INSIDE Educación Continua ODONTOLOGÍA RESTAURADORA PERIODONCIA
Blanqueamiento del diente unitario oscurecido
Cambiar el color de un solo un diente del sector anterior implica unos retos particulares Por Van Haywood DMD y Anthony J. DiAngelis DMD MPH
Cuando un paciente presenta decoloración o tinción, tanto intrínseca como extrínseca, que sugiere un tratamiento mediante blanqueamiento dental, existen una serie de factores a tener en cuenta y varias opciones que el clínico debe considerar: ¿Cuál es la causa de la decoloración? ¿Ha habido un traumatismo previo? ¿Ha sido el diente tratado con endodoncia? ¿Cuál es el mejor método a ofrecer para el estilo de vida, situación financiera y grado de compromiso del paciente par el cumplimiento del tratamiento domiciliario?. El diente unitario oscurecido representa un reto importante a la hora de obtener un cambio de color y el clínico debe conocer los principios básicos del cambio de color de uno o varios dientes con el propósito de implementar un plan de tratamiento exitoso.
RESUMEN'
El'diente'unitario'oscurecido'representa'un'reto'importante'a'la'hora'de'obtener'los'mejores' resultados' esté:cos' para' la' sonrisa' del' paciente.' Las' opciones' de'tratamiento' incluyen' coronas' unitarias,' carillas' de' cerámica,' composite' de'recubrimiento,' o' blanqueamiento.' El' blanqueamiento' es' la' opción' más'conservadora' a' considerar' si' bien' el' potencial' para' alcanzar' un' tratamiento'exitoso'varía'en'relación'a'la'causa'y'extensión'de'la'decoloración.'
42 INSIDE DENTISTRY | September 2010 | insidedentistry.net
Bleaching the Single Dark ToothChanging the color of just one anterior tooth presents unique challenges.By Van B. Haywood, DMD | Anthony J. DiAngelis, DMD, MPH
W hen a patient presents with either intrin-sic or extrin-sic staining or discoloration and seems to
be a candidate for tooth bleaching, there is a variety of factors and options for the clinician to consider. What is the cause for the discoloration? Is there tooth trauma involved, or has the a!ected tooth been endodontically treated? What is the best delivery method for the patient’s lifestyle, financial situation, and commitment level to home care? Single dark teeth present a unique chal-lenge for color change and the clinician
must be aware of the basic principles of changing the color of one or more teeth in order to implement a successful treat-ment plan.
The Initial ExaminationThe first and most important con-sideration is to determine the cause of the tooth discoloration. A clinical examination is conducted, which in-cludes evaluation of the color of the teeth and the adjacent gingiva (Figure 1). Additionally, transillumination, ra-diographs, and pulp testing may be ap-propriate. Radiographs should always be taken of a single dark tooth, as teeth can undergo pulpal necrosis without any other symptom than becoming dark (Figure 2). From this examination, the determination is made of whether the tooth is vital or not. A vital tooth may be darker due to trauma and resultant bleeding into the dental tubules with-out loss of vitality. Vital teeth may also discolor from internal or external re-sorption, calcific metamorphosis, as well as decay or leaking restorations on the proximal or lingual surfaces. A non-vital tooth may have become darker from the same reasons as a vital tooth, but also have experienced pulpal death. A tooth that has received endodontic treatment may also later darken, especially if there is a poor seal of the endodontic access opening (Figure 3).
Even if a tooth tests as non-vital, it may not require endodontic therapy. If there is no radiographic evidence of pa-thology and no clinical symptoms, then
there is no reason to initiate endodontic therapy based on vitality testing alone. Often single dark teeth are the result of trauma, which should be determined in the dental history. It can take anywhere from 1 to 20 years after the trauma be-fore any pulpal problems develop.
Additional considerations for the single dark tooth are the color of the gingival tissues around the tooth, as well as whether there is any root structure visible due to recession. A smile analysis is used to determine these conditions as well as the movement of the lip during smiling and whether a “gummy smile” exists. The dentin in the root is di!er-ent from the dentin in the anatomic crown, and does not bleach well if at all, regardless of whether internal or external bleaching is attempted. Also, discolorations of the gingiva may cause a tooth that may be a perfect color match to not be harmonious. Either of these conditions is magnified if the lip exposes much of the root or gingiva because of a hyperactive lip or gummy smile.
Trauma and Calcific MetamorphosisMany studies suggest that the preva-lence of traumatic dental injuries (TDI) is high, although significant variation occurs between countries, populations, age, and gender.1-4 Epidemiological studies, while not always comparable, support the growing body of evidence that TDIs represent a significant chal-lenge for clinicians.5 A study by Koste and colleagues reported that 25% of 6- to 50-year-olds in the United States had experienced a TDI.6 Approximately 30% of children have sustained a TDI to their primary dentition, and 25% of all school-aged children have experienced a TDI.7-9 Other reports document that luxations represent the majority of primary teeth injuries, whereas crown fractures constitute the most commonly
occurring injury in permanent teeth.10,11 Also, studies have reported that 71% to 92% of TDIs occur by age 19.12
The etiology of dental injuries varies by age. In the 0 to 6 age group, falls pre-dominate.13 As children enter school, falls, collisions with other children and objects, as well as participation in organized physical activities and sports contribute to dental injuries.9,14-16 TDIs in the teen and young-adult age group are more the result of sports and motor vehicle accidents.14 Several studies have documented that approximately one third of dental injuries are sports-re-lated.15-23 Other causes of TDIs include physical abuse, fights, and assaults—of-ten involving alcohol as an aggravating factor.24-26
The pulp can respond to trauma in a limited number of ways. Primarily it can survive, die, or undergo pulp canal obliteration (PCO), often referred to as calcific metamorphosis.27 The latter represents a common finding subse-quent to luxation injuries, 3.8% to 24%, and root fractures, 69% to 73%.2,28-30
The precise mechanism of PCO is not known but disruption of the neurovas-cular bundle appears to stimulate the rapid formation of hard tissue (dentin or osseous) beginning within the pulp chamber and progressing along the pulp canal walls.31 It may present as partial or total obliteration of the pulp canal space. Although radiographs may reveal what appears to be total oblitera-tion of the pulp canal, generally there remains clinical evidence of a pulp canal and pulpal tissue.32,33 Clinically, the tooth will appear dark yellow due
VAN B. HAYWOOD, DMDProfessor Director of DentalContinuing EducationDepartment of Oral RehabilitationSchool of Dentistry Medical College of GeorgiaAugusta, Georgia
ANTHONY J. DIANGELIS, DMD, MPHChief Department of Dentistry Hennepin County Medical CenterMinneapolis, Minnesota
ProfessorUniversity of MinnesotaMinneapolis, Minnesota
ABSTRACTSingle dark teeth represent a major challenge to obtain best esthetic outcome in a patient’s smile. Treatment options may include single crowns, veneers, bonding, or bleaching. Bleaching is the most conservative option to consider, but the potential for a successful outcome varies based on the cause and extent of the discoloration.
INSIDE CONTINUING EDUCATION RESTORATIVEPERIODONTICS
Learning Objectives
VAN$B.$HAYWOOD,$$DMD$Catedrá5co$Director$de$Educación$Dental$Con5nua$Departamento$de$Rehabilitación$Oral$Escuela$de$Odontología$Facultad$de$Medicina$de$Georgia$Augusta'(Georgia)'
42 INSIDE DENTISTRY | September 2010 | insidedentistry.net
Bleaching the Single Dark ToothChanging the color of just one anterior tooth presents unique challenges.By Van B. Haywood, DMD | Anthony J. DiAngelis, DMD, MPH
W hen a patient presents with either intrin-sic or extrin-sic staining or discoloration and seems to
be a candidate for tooth bleaching, there is a variety of factors and options for the clinician to consider. What is the cause for the discoloration? Is there tooth trauma involved, or has the a!ected tooth been endodontically treated? What is the best delivery method for the patient’s lifestyle, financial situation, and commitment level to home care? Single dark teeth present a unique chal-lenge for color change and the clinician
must be aware of the basic principles of changing the color of one or more teeth in order to implement a successful treat-ment plan.
The Initial ExaminationThe first and most important con-sideration is to determine the cause of the tooth discoloration. A clinical examination is conducted, which in-cludes evaluation of the color of the teeth and the adjacent gingiva (Figure 1). Additionally, transillumination, ra-diographs, and pulp testing may be ap-propriate. Radiographs should always be taken of a single dark tooth, as teeth can undergo pulpal necrosis without any other symptom than becoming dark (Figure 2). From this examination, the determination is made of whether the tooth is vital or not. A vital tooth may be darker due to trauma and resultant bleeding into the dental tubules with-out loss of vitality. Vital teeth may also discolor from internal or external re-sorption, calcific metamorphosis, as well as decay or leaking restorations on the proximal or lingual surfaces. A non-vital tooth may have become darker from the same reasons as a vital tooth, but also have experienced pulpal death. A tooth that has received endodontic treatment may also later darken, especially if there is a poor seal of the endodontic access opening (Figure 3).
Even if a tooth tests as non-vital, it may not require endodontic therapy. If there is no radiographic evidence of pa-thology and no clinical symptoms, then
there is no reason to initiate endodontic therapy based on vitality testing alone. Often single dark teeth are the result of trauma, which should be determined in the dental history. It can take anywhere from 1 to 20 years after the trauma be-fore any pulpal problems develop.
Additional considerations for the single dark tooth are the color of the gingival tissues around the tooth, as well as whether there is any root structure visible due to recession. A smile analysis is used to determine these conditions as well as the movement of the lip during smiling and whether a “gummy smile” exists. The dentin in the root is di!er-ent from the dentin in the anatomic crown, and does not bleach well if at all, regardless of whether internal or external bleaching is attempted. Also, discolorations of the gingiva may cause a tooth that may be a perfect color match to not be harmonious. Either of these conditions is magnified if the lip exposes much of the root or gingiva because of a hyperactive lip or gummy smile.
Trauma and Calcific MetamorphosisMany studies suggest that the preva-lence of traumatic dental injuries (TDI) is high, although significant variation occurs between countries, populations, age, and gender.1-4 Epidemiological studies, while not always comparable, support the growing body of evidence that TDIs represent a significant chal-lenge for clinicians.5 A study by Koste and colleagues reported that 25% of 6- to 50-year-olds in the United States had experienced a TDI.6 Approximately 30% of children have sustained a TDI to their primary dentition, and 25% of all school-aged children have experienced a TDI.7-9 Other reports document that luxations represent the majority of primary teeth injuries, whereas crown fractures constitute the most commonly
occurring injury in permanent teeth.10,11 Also, studies have reported that 71% to 92% of TDIs occur by age 19.12
The etiology of dental injuries varies by age. In the 0 to 6 age group, falls pre-dominate.13 As children enter school, falls, collisions with other children and objects, as well as participation in organized physical activities and sports contribute to dental injuries.9,14-16 TDIs in the teen and young-adult age group are more the result of sports and motor vehicle accidents.14 Several studies have documented that approximately one third of dental injuries are sports-re-lated.15-23 Other causes of TDIs include physical abuse, fights, and assaults—of-ten involving alcohol as an aggravating factor.24-26
The pulp can respond to trauma in a limited number of ways. Primarily it can survive, die, or undergo pulp canal obliteration (PCO), often referred to as calcific metamorphosis.27 The latter represents a common finding subse-quent to luxation injuries, 3.8% to 24%, and root fractures, 69% to 73%.2,28-30
The precise mechanism of PCO is not known but disruption of the neurovas-cular bundle appears to stimulate the rapid formation of hard tissue (dentin or osseous) beginning within the pulp chamber and progressing along the pulp canal walls.31 It may present as partial or total obliteration of the pulp canal space. Although radiographs may reveal what appears to be total oblitera-tion of the pulp canal, generally there remains clinical evidence of a pulp canal and pulpal tissue.32,33 Clinically, the tooth will appear dark yellow due
VAN B. HAYWOOD, DMDProfessor Director of DentalContinuing EducationDepartment of Oral RehabilitationSchool of Dentistry Medical College of GeorgiaAugusta, Georgia
ANTHONY J. DIANGELIS, DMD, MPHChief Department of Dentistry Hennepin County Medical CenterMinneapolis, Minnesota
ProfessorUniversity of MinnesotaMinneapolis, Minnesota
ABSTRACTSingle dark teeth represent a major challenge to obtain best esthetic outcome in a patient’s smile. Treatment options may include single crowns, veneers, bonding, or bleaching. Bleaching is the most conservative option to consider, but the potential for a successful outcome varies based on the cause and extent of the discoloration.
INSIDE CONTINUING EDUCATION RESTORATIVEPERIODONTICS
Learning Objectives
ANTHONY$J$DIANGELIS,$$DMD,$$MPH$Jefe$del$Departamento$de$Odontología$Complejo$Hospitalario$$del$Condado$de$Hennepin$Minneapolis,'Minnesota'Catedrá5co$Universidad$de$Minnesota$Minneapolis,'Minnesota'
El Examen Inicial La primera y más importante consideración es determinar la causa de la decoloración del diente. Se lleva a cabo un examen clínico que incluye la valoración del color del diente y la encía adyacente (Figura 1). Adicionalmente, pueden ser necesarias la transiluminación, pruebas radiográficas y tests pulpares. Se deben realizar siempre radiografías del diente oscurecido porque puede haber una necrosis pulpar sin otro síntoma que la decoloración (Figura 2). Tras este examen se determina si el diente está vital o no. Un diente vital puede haberse oscurecido debido al traumatismo y al sangrado resultante dentro de los túbulos dentinarios sin perder su vitalidad. El diente vital puede decolorarse por reabsorción externa o interna, metamorfosis cálcificante, caries, o filtraciones que afecten a restauraciones localizadas en las superficies proximales o linguales del diente. Un diente no vital puede haberse oscurecido por las mismas razones pero adicionalmente haber sufrido una necrosis pulpar. El diente que ha recibido tratamiento endodóncico puede oscurecerse posteriormente al tratamiento de conductos, en especial si no se ha sellado adecuadamente la cavidad de apertura (figura 3). Aunque los tests pulpares definan un diente como no vital puede que no requiera tratamiento endodóncico si no muestra evidencias radiográficas de patología ni síntomas clínicos, en consecuencia, no hay razones para iniciar un tratamiento endodóncico basándose únicamente en los test pulpares. A menudo, el diente unitario decolorado es el resultado de un traumatismo que se aclara durante la historia clínica pudiendo haber ocurrido entre 1 y 20 años antes de que se desarrolle cualquier problema pulpar.
44 INSIDE DENTISTRY | September 2010 | insidedentistry.net
INSIDE CONTINUING EDUCATION
the form of a discolored incisor presents a long-term esthetic challenge. The most conservative approach to managing PCO-induced discoloration is bleach-ing without endodontic therapy.
Tray BleachingThere are a number of types of bleach-ing techniques to consider for both vital and non-vital teeth, but these types may be divided mainly into those performed in-o!ce or those continued at home. With the advent of nightguard vital bleaching involving tray application of 10% carbamide peroxide, a method for bleaching single dark teeth became more readily available, and did not in-volve the use of highly caustic chemi-cals.43 The original recommendation for a single dark tooth was to make a non-scalloped, no-reservoir tray, and bleach all the teeth. The tooth that was darker generally took longer, so an “X” was made on that tooth mold of the tray so the patient could continue to bleach that tooth longer than the other teeth. The use of the “X” on the teeth to be bleached was also helpful when the pa-tient already had crowns on some teeth, and placing bleaching material on them was a waste of material. While this tray system was simple and e"ective, it did not always result in a perfect match of the teeth. All the teeth would lighten, but often the darker tooth was not able to lighten as much as the normal teeth, and the resultant outcome was lighter teeth, but still with one tooth slightly darker than the others. Some authors have recommended using a reservoir on the darker tooth, but the use of res-ervoirs has not been shown to increase
bleaching e!cacy.44 It is not possible to “spot bleach” a tooth either, because the bleaching material goes through the enamel and dentin to the pulp in 5 to 15 minutes, and bleaches under res-torations and from one surface to the other (facial to lingual). It has also been shown to bleach beyond the borders of the tray, generally to the cementoe-namel junction (CEJ), even if the tooth is only partially erupted.
The ideal bleaching tray is fabricated on a horseshoe-shaped cast with no vestibule to provide good adaptation of the bleaching tray material. Also, the cast should be trimmed such that the central incisors are vertical to avoid folds on the facial. One challenge in fabrication of the single-tooth or regu-lar bleaching tray is trimming the cast without abrading either the teeth or the gingiva. This outcome is accomplished by trimming the cast from the base rather than the sides (Figure 5).
Single-Tooth Bleaching TrayAn improvement on this concept is the use of the “single-tooth” bleaching tray when one tooth is darker, but the other teeth are reasonably acceptable (Figure 6). In this tray design, a conven-tional non-scalloped, no-reservoir tray is fabricated. Then the teeth molds on either side of the dark tooth are removed (Figure 7 and Figure 8). The patient is given one syringe of bleaching mate-rial and applies it only to the single dark tooth mold and sleeps in the appliance. Teeth will bleach at di"erent rates and to di"erent color levels. The goal is to de-termine how light the single dark tooth will bleach first. If the color of the single
to the increased deposition of under-lying dentin. Additionally, there may be a gradual diminution in response to electrical and thermal pulp testing. PCO occurs more frequently in teeth with open apices and in more severe luxation injuries involving displace-ment.2,34 Extrusive and lateral luxation injuries in immature permanent teeth have demonstrated high rates of PCO.35 A recent study by Netto and colleagues reported the chances of PCO in in-truded permanent teeth to be six times greater than in mature teeth, open vs closed apex, and that PCO occurred in 26.7% of such injuries.36 PCO can oc-cur in subluxated and crown-fractured teeth, although with less frequency.37
As mentioned previously, PCO is a common occurrence after root frac-tures. The location of PCO is thought to be indicative of the type of healing. PCO in the apical segment only is sug-gestive of hard-tissue callus formation, whereas PCO in the coronal segment or in both coronal and apical fracture seg-ments is indicative of connective tissue repair of the fracture.2,38
Pulp necrosis as evidenced by periapi-cal radiolucency is an infrequent sequela to PCO occurring in approxi mately 7% to 16% of cases; consequently, prophy-lactic endodontic therapy is not recom-mended by most authors.28,39-41 Teeth with PCO likely have diminished heal-ing capacity, and it is not well established whether a secondary trauma or addi-tional dental treatment causes necro-sis. In some instances, such as prepar-ing a tooth with PCO for an abutment, it may be prudent to perform prophylactic endodontic therapy before the definitive
restorative procedure. A recent article by daCunha and colleagues suggests implementing endodontic therapy prior to development of a periapical radiolu-cency in a tooth with PCO, based on two major considerations: (1) the technical di!culty and complications that may occur in treating these teeth; and (2) their review of a study that demonstrat-ed a 97.9% success rate for teeth treated without periapical radiolucencies vs a 62.5% success rate for teeth treated with periapical radiolucencies.42 Specific clinical situations will dictate clinical decisions; however, given the relatively low incidence of pulp necrosis in teeth with PCO, endodontic treatment usually is not recommended in the absence of a periapical radiolucency or symptoms. Nonetheless, if a periapical lesion de-velops, endodontic therapy can be both challenging and fraught with complica-tions (Figure 4). The use of operatory microscopes in the hands of a skilled clinician is warranted and improves the chances of a successful outcome.
Most traumas to primary teeth are luxation injuries that frequently result in radiographic evidence of PCO. Although this may or may not result in crown dis-coloration, it ceases to be a concern for the patient, parent, or clinician as the tooth is eventually exfoliated. The only indication for bleaching primary teeth, which are generally very light, is trauma that caused the tooth to become dark and the patient is being a"ected psychologi-cally by the darker teeth. There is no in-dication for endodontic therapy.
In contrast, younger patients who sustain TDIs where development of the permanent tooth is incomplete, PCO in
CLINICAL EXAMPLES (3.) A radiograph will indicate wheth-er the dark color is related to materials remaining in the pulp chamber, leaking restorations, caries, internal resorption, or failed endodontic therapy. (4.) Endodontic therapy was attempted on a tooth with calcific metamorphosis, with subsequent perforation and file fracture in the PDL.
FIG. 4FIG. 1 FIG. 2
CLINICAL EXAMPLES (1.) A clinical examination demonstrates a single, very dark lateral incisor and a moderately dark central incisor with a crown on the adjacent central incisor and several dark gingival areas. (2.) A radiograph finds no pulp chamber in the slightly dark central incisor and a silver point on the darkest lateral incisor. A titrated approach to bleaching was needed us-ing individual tooth treatments.
FIG. 3
Fig.% 1=% El% examen% clínico% muestra% un% único% incisivo% lateral% muy% oscurecido% y% un% incisivo%central% moderadamente% oscuro% con% una% corona% en% el% incisivo% central% adyacente% y% varias%áreas% gingivales% oscuras.% Fig.% 2=% La% radiogra=a% no% detecta% cámara% pulpar% en% el% incisivo%central%ligeramente%oscuro%y%hay%una%punta%de%plata%en%el%incisivo%lateral%más%oscurecido.%Se%necesita% una% tentaAva% evaluaAva% de% blanqueamiento% uAlizando% tratamientos% de% dientes%individualizados.%
44 INSIDE DENTISTRY | September 2010 | insidedentistry.net
INSIDE CONTINUING EDUCATION
the form of a discolored incisor presents a long-term esthetic challenge. The most conservative approach to managing PCO-induced discoloration is bleach-ing without endodontic therapy.
Tray BleachingThere are a number of types of bleach-ing techniques to consider for both vital and non-vital teeth, but these types may be divided mainly into those performed in-o!ce or those continued at home. With the advent of nightguard vital bleaching involving tray application of 10% carbamide peroxide, a method for bleaching single dark teeth became more readily available, and did not in-volve the use of highly caustic chemi-cals.43 The original recommendation for a single dark tooth was to make a non-scalloped, no-reservoir tray, and bleach all the teeth. The tooth that was darker generally took longer, so an “X” was made on that tooth mold of the tray so the patient could continue to bleach that tooth longer than the other teeth. The use of the “X” on the teeth to be bleached was also helpful when the pa-tient already had crowns on some teeth, and placing bleaching material on them was a waste of material. While this tray system was simple and e"ective, it did not always result in a perfect match of the teeth. All the teeth would lighten, but often the darker tooth was not able to lighten as much as the normal teeth, and the resultant outcome was lighter teeth, but still with one tooth slightly darker than the others. Some authors have recommended using a reservoir on the darker tooth, but the use of res-ervoirs has not been shown to increase
bleaching e!cacy.44 It is not possible to “spot bleach” a tooth either, because the bleaching material goes through the enamel and dentin to the pulp in 5 to 15 minutes, and bleaches under res-torations and from one surface to the other (facial to lingual). It has also been shown to bleach beyond the borders of the tray, generally to the cementoe-namel junction (CEJ), even if the tooth is only partially erupted.
The ideal bleaching tray is fabricated on a horseshoe-shaped cast with no vestibule to provide good adaptation of the bleaching tray material. Also, the cast should be trimmed such that the central incisors are vertical to avoid folds on the facial. One challenge in fabrication of the single-tooth or regu-lar bleaching tray is trimming the cast without abrading either the teeth or the gingiva. This outcome is accomplished by trimming the cast from the base rather than the sides (Figure 5).
Single-Tooth Bleaching TrayAn improvement on this concept is the use of the “single-tooth” bleaching tray when one tooth is darker, but the other teeth are reasonably acceptable (Figure 6). In this tray design, a conven-tional non-scalloped, no-reservoir tray is fabricated. Then the teeth molds on either side of the dark tooth are removed (Figure 7 and Figure 8). The patient is given one syringe of bleaching mate-rial and applies it only to the single dark tooth mold and sleeps in the appliance. Teeth will bleach at di"erent rates and to di"erent color levels. The goal is to de-termine how light the single dark tooth will bleach first. If the color of the single
to the increased deposition of under-lying dentin. Additionally, there may be a gradual diminution in response to electrical and thermal pulp testing. PCO occurs more frequently in teeth with open apices and in more severe luxation injuries involving displace-ment.2,34 Extrusive and lateral luxation injuries in immature permanent teeth have demonstrated high rates of PCO.35 A recent study by Netto and colleagues reported the chances of PCO in in-truded permanent teeth to be six times greater than in mature teeth, open vs closed apex, and that PCO occurred in 26.7% of such injuries.36 PCO can oc-cur in subluxated and crown-fractured teeth, although with less frequency.37
As mentioned previously, PCO is a common occurrence after root frac-tures. The location of PCO is thought to be indicative of the type of healing. PCO in the apical segment only is sug-gestive of hard-tissue callus formation, whereas PCO in the coronal segment or in both coronal and apical fracture seg-ments is indicative of connective tissue repair of the fracture.2,38
Pulp necrosis as evidenced by periapi-cal radiolucency is an infrequent sequela to PCO occurring in approxi mately 7% to 16% of cases; consequently, prophy-lactic endodontic therapy is not recom-mended by most authors.28,39-41 Teeth with PCO likely have diminished heal-ing capacity, and it is not well established whether a secondary trauma or addi-tional dental treatment causes necro-sis. In some instances, such as prepar-ing a tooth with PCO for an abutment, it may be prudent to perform prophylactic endodontic therapy before the definitive
restorative procedure. A recent article by daCunha and colleagues suggests implementing endodontic therapy prior to development of a periapical radiolu-cency in a tooth with PCO, based on two major considerations: (1) the technical di!culty and complications that may occur in treating these teeth; and (2) their review of a study that demonstrat-ed a 97.9% success rate for teeth treated without periapical radiolucencies vs a 62.5% success rate for teeth treated with periapical radiolucencies.42 Specific clinical situations will dictate clinical decisions; however, given the relatively low incidence of pulp necrosis in teeth with PCO, endodontic treatment usually is not recommended in the absence of a periapical radiolucency or symptoms. Nonetheless, if a periapical lesion de-velops, endodontic therapy can be both challenging and fraught with complica-tions (Figure 4). The use of operatory microscopes in the hands of a skilled clinician is warranted and improves the chances of a successful outcome.
Most traumas to primary teeth are luxation injuries that frequently result in radiographic evidence of PCO. Although this may or may not result in crown dis-coloration, it ceases to be a concern for the patient, parent, or clinician as the tooth is eventually exfoliated. The only indication for bleaching primary teeth, which are generally very light, is trauma that caused the tooth to become dark and the patient is being a"ected psychologi-cally by the darker teeth. There is no in-dication for endodontic therapy.
In contrast, younger patients who sustain TDIs where development of the permanent tooth is incomplete, PCO in
CLINICAL EXAMPLES (3.) A radiograph will indicate wheth-er the dark color is related to materials remaining in the pulp chamber, leaking restorations, caries, internal resorption, or failed endodontic therapy. (4.) Endodontic therapy was attempted on a tooth with calcific metamorphosis, with subsequent perforation and file fracture in the PDL.
FIG. 4FIG. 1 FIG. 2
CLINICAL EXAMPLES (1.) A clinical examination demonstrates a single, very dark lateral incisor and a moderately dark central incisor with a crown on the adjacent central incisor and several dark gingival areas. (2.) A radiograph finds no pulp chamber in the slightly dark central incisor and a silver point on the darkest lateral incisor. A titrated approach to bleaching was needed us-ing individual tooth treatments.
FIG. 3
Fig.% 3=% La% radiogra-a% indicará% si% el% color% oscuro% está%relacionado% con% materiales% depositados% en% la% cámara%pulpar,% restauraciones% filtradas,% caries,% reabsorción%interna%o%fracaso%de%la%terapia%endodóncica.%Fig.%4=%Se%intentó%una%terapia%endodóncica%en%un%diente%con% metamorfosis% calcificante,% con% subsecuente%perforación%y%fractura%en%el%PDL.%
Otras consideraciones respecto al diente unitario decolorado son el color de la encía adyacente, o si hay estructura radicular visible por causa de una recesión. El análisis de la sonrisa se utiliza para determinar tales condiciones, el movimiento del labio en sonrisa, o si existe sonrisa gingival. La dentina radicular es diferente a la dentina de la corona anatómica y generalmente no blanquea bien independientemente de que se intente un blanqueamiento externo o interno. Los cambios de color de la encía también pueden producir que un diente de un color adecuado resulte no ser armonioso. Cualquiera de estas condiciones se magnifica si el labio expone una porción sustancial de la raíz y de la encía debido a un labio hiperactivo o a una sonrisa gingival. Trauma y Metamorfosis Calcificante La mayoría de los estudios publicados sugieren que la prevalencia de lesiones dentales traumáticas (LDT) es elevada, aunque existen diferencias significativas entre países, poblaciones, edades y sexo.1-‐4 Los estudios epidemiológicos, aunque no son comparables, sugieren una evidencia creciente de que las LDT representan un reto significativo para los clínicos.5 Un estudio de Koste y cols. refiere que el 25% de los habitantes de EEUU entre 6 y 50 años de edad ha experimentado una LDT.6 Aproximadamente el 30% de los niños ha sufrido una lesión traumática en su dentición primaria y el 25% de los niños en edad escolar ha experimentado una LDT.7-‐9 Otros trabajos documentan que las luxaciones representan la mayoría de las lesiones en los dientes primarios, mientras que las fracturas coronales constituyen las más comunes en los dientes permanentes.10 11 La etiología de las lesiones dentales varía con la edad. En el grupo de 0 a 6 años predominan las caídas.13 En los niños en edad escolar, las caídas, colisiones con otros niños u objetos, así como la participación en actividades físicas organizadas y deportes, son los contribuyentes principales de las lesiones dentarias.9, 14-‐16 Las LDT en los adolescentes y adultos jóvenes son generalmente causados por los deportes y los accidentes de circulación.14 Varios estudios han documentado que aproximadamente un tercio de las lesiones dentales están relacionadas con el deporte.15-‐23 Otras causas de LDT incluyen los abusos físicos, peleas y asaltos, que a menudo incluyen el alcohol como factor agravante.24-‐26 La pulpa puede responder al traumatismo con un número limitado de variantes. Fundamentalmente puede sobrevivir, necrosarse o resultar en una obliteración del canal pulpar (OCP), a menudo reseñada como metamorfosis calcificante.27 Esta última representa un hallazgo común posterior a las lesiones por luxación (3,8-‐24%), y más frecuentemente a las fracturas radiculares (69-‐73%).2,28-‐30 Aunque el mecanismo preciso de la OCP no se conoce, parece que la disrupción del paquete neurovascular estimula una rápida formación de tejidos duros (dentina o hueso) que comienza en la cámara pulpar y se va extendiendo a lo largo de las paredes del canal,31 pudiendo presentarse como una obliteración total o parcial del canal pulpar. Aunque las radiografías pudiesen revelar lo que parece una obliteración total del canal pulpar, generalmente permanecen evidencias clínicas de canal y tejido pulpar.32,33 Clínicamente, el diente aparece amarillo oscuro debido a una aposición incrementada de dentina subyacente y pudiese haber una disminución gradual del la respuesta térmica y eléctrica de los tests pulpares.
La OCP ocurre con más frecuencia en dientes con ápices abiertos y en las luxaciones que conllevan un desplazamiento lateral severo.2,34 Los dientes permanentes inmaduros que han sufrido luxación lateral y extrusiva han demostrado altos niveles de OCP.35 Un estudio reciente realizado por Netto y cols. refiere que los eventos de la OCP en la intrusión dentaria ocurren con una frecuencia seis veces superior en los dientes con ápice inmaduro, y que se producen en el 26,7% de tales lesiones.36 La OCP puede presentarse en los dientes con subluxación y fractura coronaria, aunque con una frecuencia inferior.37 Como se ha mencionado previamente, la OCP es un hecho frecuente después de las fracturas radiculares. Se cree que la localización de la OCP es indicativa del tipo de cicatrización. La OCP que se circunscribe al segmento apical sugiere el desarrollo de un callo de tejido duro, mientras que la localización de la OCP en el segmento coronal, o en ambos segmentos, coronal y apical, son indicativos de reparación de fractura con tejido conectivo.2,38 La necrosis pulpar evidenciada como radiolucidez apical es una secuela infrecuente de la OCP que ocurre solamente en 7-‐16% de los casos; y en consecuencia la mayoría de los autores no recomienda la endodoncia profiláctica.28,39-‐41 Los dientes con OCP suelen tener una capacidad de cicatrización disminuida y no ha quedado verificado si los traumatismos ulteriores o tratamientos odontológicos adicionales sobre el diente puedan causar necrosis. En algunos casos, como cuando se prepara el diente como pilar para prótesis fija, puede ser prudente realizar la endodoncia profiláctica antes de realizar el tratamiento restaurador definitivo. Un artículo reciente de daCunha y cols. sugiere realizar la terapia endodóncica antes de que se desarrolle la radiolucidez en un diente con OPC basándose en las siguientes consideraciones principales:
1. Las complicaciones y dificultades técnicas que pudiesen ocurrir durante el tratamiento de esos dientes.
2. Su reseña de un estudio que demostraba un porcentaje de éxitos del 97,9% en los dientes tratados que no presentaban radiolucidez periapical, frente al 62,5% en los dientes que sí la presentaban.42
Situaciones clínicas particulares orientarán decisiones clínicas específicas, sin embargo, dada la relativa baja incidencia de necrosis pulpar en los dientes con OCP, no se recomienda el tratamiento endodóncico habitual en ausencia de radiolucidez periapical y síntomas. No obstante, si se desarrolla una lesión periapical la terapia endodoncia puede ser tan dificultosa como llena de complicaciones (Figura 4). El uso de microscopio de endodoncia en mano expertas garantiza y mejora las posibilidades de un tratamiento exitoso. La mayoría de los traumatismos de los dientes primarios sufren lesiones por luxación que con frecuencia muestran evidencias radiográficas de OCP. Aunque ello pudiese resultar o no en una decoloración de la corona, representan un problema para el paciente, los padres y el odontólogo, ya que el diente eventualmente se exfolia. La única indicación para blanquear un diente de leche con tinción, que en todo caso suele ser discreta, sería la repercusión psicológica que produzca la presencia del diente oscuro en el paciente. No existe indicación para la terapia endodóncica. Por el contrario, en los pacientes más jóvenes que padezcan LDT sobre un diente permanente inmaduro, la decoloración y la OCP pueden producir un menoscabo
estético duradero y en tales casos, el modo más conservador de afrontarlo es realizar un blanqueamiento coronal sin realizar el tratamiento endodóncico. Blanqueamiento Con Cubetas Hay diferentes tipos de técnicas de blanqueamiento a considerar para el tratamiento tanto de dientes vitales como no vitales, pero todos pueden dividirse fundamentalmente en aquellos que se realizan en el consultorio y los que se continúan en el domicilio. Tras la llegada del blanqueamiento vital nocturno con peróxido de carbamida al 10% en cubetas, el blanqueamiento del diente unitario se ha transformado en un procedimiento de uso inmediato que no requiere el uso de productos químicos altamente cáusticos.43 La recomendación original en el blanqueamiento del diente unitario era fabricar una cubeta no festoneada y sin reservorio, y blanquear el total de la arcada. El diente oscurecido requiere más tiempo, por lo que debería de marcarse con una X en el molde para que el paciente mantenga el blanqueamiento de ese diente durante mayor tiempo que el resto de los dientes. Marcar con una X el diente del molde a blanquear también es útil cuando el paciente es portador de coronas en algún diente para evitar que se gaste material inútilmente. Este procedimiento de cubetas era simple y efectivo pero no siempre conseguía igualar el color del diente. Al final todos los dientes finalizaban más blancos, pero a menudo el diente oscurecido no conseguía blanquearse tan eficazmente y el resultado era una arcada blanqueada con un diente ligeramente más oscuro que el resto. Algunos autores han recomendado el uso de reservorios en la porción de la cubeta del diente a tratar, pero con el uso de reservorios no se ha demostrado una mayor eficacia blanqueadora.44 Tampoco es posible intentar un blanqueamiento localizado de la mancha porque el material blanqueador atraviesa el esmalte y la dentina hacia la pulpa en un periodo de 5 a 15 minutos, blanquea bajo las restauraciones y también desde una superficie a otra (desde vestibular a lingual). Se ha visto que el blanqueamiento se produce más allá de los bordes de la cubeta, generalmente hasta la unión amelo-‐cementaria, incluso si el diente no ha erupcionado totalmente. La cubeta de blanqueamiento ideal se fabrica con acabado en forma de herradura y sin vestíbulo para proporcionar una buena adaptación al material blanqueador. El molde debe recortarse hasta que los incisivos centrales encajen en vertical sin que se produzcan pliegues en la porción vestibular de la cubeta. Uno de los retos en la fabricación tanto de cubetas de blanqueamiento ordinarias como de dientes unitarios, es recortar el molde sin desgastar el diente o la encía, este resultado se consigue recortando el molde por la base, en vez de por los lados (Figura 5). Cubetas Para Blanqueamiento De Diente Unitario Cuando solamente un diente está oscuro pero el resto tiene un color razonablemente aceptable (Figura 6) se usan cubetas de blanqueamiento para diente unitario. En este diseño, se fabrica una cubeta convencional no festoneada y sin reservorio y luego se recortan los dientes adyacentes al diente a tratar (Figuras 7 y 8).
Se le proporciona al paciente una jeringa de material blanqueador para que lo aplique solamente en el diente oscurecido y duerma con el aparato puesto. El diente irá blanqueando progresivamente en niveles de intensidad y color, el objetivo es determinar cuanto se aclara el color del diente en este primer intento. Si el diente oscuro no llega a aclararse hasta el nivel de color de los dientes adyacentes, entonces no se procederá a blanquear el resto (Figura 9). Tampoco se hará si el diente consigue el color deseado, solamente si el diente unitario blanquea en mayor medida que el resto se procederá al blanqueamiento, pero en este caso, se hará un blanqueamiento diurno en intervalos cortos para evitar que los dientes de la arcada se blanqueen más que el diente blanqueado. Generalmente, el paciente debe estar informado que el procedimiento para blanquear un diente unitario se prolonga unas 8 semanas, aunque este periodo es muy variable. Dientes anteriores tratados con endodoncia Si el diente oscurecido ha sido tratado con endodoncia, consideraciones adicionales para el tratamiento de la decoloración incluyen la presencia de materiales pulpares dentro de la cámara, selladores o relleno endodóncico, restauraciones oscuras o filtradas en el acceso endodóncico, así como el fracaso endodóncico. El tipo de relleno es también importante porque las puntas de plata plantean diferentes consideraciones respecto a las puntas de gutapercha. Las consideraciones terapéuticas también dependen de cuando se ha hecho patente el oscurecimiento del diente, si durante la terapia endodóncica o en el seguimiento ulterior.
46 INSIDE DENTISTRY | September 2010 | insidedentistry.net
INSIDE CONTINUING EDUCATION
dark tooth does not get as light as the sur-rounding teeth, then the other teeth are not bleached (Figure 9) and the closest match has been achieved. If the single dark tooth matches the other teeth then, again, the other teeth are not bleached. Only if the single dark tooth gets lighter than the adjacent teeth should they be bleached, and in that case, daytime bleaching in short intervals should be used to avoid getting the adjacent teeth lighter than the single dark bleached tooth. Generally, the patient should be informed that the bleaching time for the single dark tooth is about 8 weeks, although it is highly variable.
Endodontically Treated Anterior TeethIf the dark tooth has already received endodontic therapy, then additional considerations for the discoloration include remaining pulp materials in the pulp chamber, endodontic sealer or filler in the pulp chamber, and dark or leaking restorations in the endodontic access opening, as well as endodontic failure. The type of filler is also impor-tant, as silver points require di!erent considerations from gutta-percha fill-ers. Treatment considerations also may depend on when in the endodontic treatment and subsequent follow-up the tooth was noticed to be dark.
Endodontically treated teeth may be treated from the inside, the outside, or both. The decision for inside or outside depends on a knowledge of what has occurred inside the tooth during the endodontic therapy, as well as the type of restoration used to seal the access opening. The tooth may have received a satisfactory endodontic treatment and
CASE EXAMPLE ONE (5.) Trimming the cast only from the base (with the central incisors horizontal) until the vestibule is removed and a hole oc-curs in the palate will avoid the danger of damaging teeth from traditional trimming as well as create the best cast for use in a vacuum-former. (6.) A single dark tooth from trauma needs to be examined carefully and evalu-ated with a radiograph. The safest approach is to bleach this tooth alone until the tooth’s response and maximum lightening can be determined. (7.) The “single-tooth” bleaching tray has no reservoir or spacers and extends onto the gingiva 1 mm to 2-mm, but avoids frenum movements. The teeth not to be bleached have the tooth molds removed from the tray while maintaining the intact tray. (8.) The single-tooth bleaching tray extended further onto the palate than the traditional tray to preserve the tray integrity when the adjacent teeth molds were removed from the tray. The tray edges are hidden behind rugae and go onto the tissue in all areas. (9.) A reasonable match was obtained from about 8 weeks of single-tooth bleaching. Often patients discontinue treatment when the single tooth is no longer a mismatch, even if the outcome is not ideal. CASE EXAMPLE TWO (10.) This root canal has been successful for 30 years, but the tooth has become slightly discolored. There is no reason from the radiograph to re-enter the pulp chamber, as this will further weaken the tooth. External bleaching by a single-tooth bleaching tray is indicated (11.) The 10% carb-amide peroxide bleaching material was applied externally with the single-tooth bleaching tray nightly until the shade of the endodontically treated tooth returned to match the adjacent teeth. Should the tooth re-darken again, the process can be repeated without danger to the tooth. Figure 10 and Figure 11 courtesy of Meigan Johnson.
FIG. 7 FIG. 8
FIG. 5 FIG. 6
FIG. 9
been subsequently restored with an ac-ceptable lingual composite that matched the tooth color. However, in subsequent years, the tooth may have discolored (Figure 10). In this situation, the deci-sion for bleaching favors external bleach-ing, because going inside the tooth to remove the composite will weaken the tooth (Figure 11). However, the choice not to go inside the endodontic tooth depends on whether the treating dentist is aware of the extent to which the pulp chamber was debrided during endodon-tic therapy, as well as the height in the chamber of the cement and filler.
In-O!ce BleachingIn-o"ce bleaching is the oldest form of bleaching. Attempts to bleach single dark teeth date back to the 1800s, and bleaching a single dark tooth was one of the first bleaching research areas.45 A number of materials have been used, but hydrogen peroxide has been the historic favorite. The high concentra-tion of hydrogen peroxide could be applied externally or internally, and often involved heat and light. The classic non-vital in-o"ce bleaching technique involved the placement of 35% hydrogen peroxide into the pulp chamber, and increasing the chemi-cal reaction by the use of heat or light. However, this technique lacks precise control as to the amount of lightening. More critically, when cases of external or internal resorption were evaluated, there were four common concerns list-ed: 1) teeth had received trauma; 2) high concentrations of peroxide were used; 3) high heat was used to enhance the bleaching, and 4) there was no seal over the gutta-percha. Although the dentist cannot control the trauma, elimination of the other three areas under dental control should be done to lessen the chances of resorption and loss of the tooth. Other possibilities for resorp-tion include the fact that 10% of teeth do not have a connection between the enamel and cementum, with possible percolation of hydrogen peroxide into the surrounding areas, lowering the pH. Using a bleaching product with a higher pH or a salivary catalase are attempts to reduce resorption issues.
Walking Bleach TechniqueThe change in in-o"ce bleaching led to the next step of “walking bleaching.” In this technique, the gutta-percha was removed 2 mm below the CEJ and a
FIG. 10 FIG. 11
“One challenge infabrication of the single-tooth or regular bleaching tray is trimming the cast without abrading either the teeth or thegingiva. This outcome is accomplishedby trimming the cast from the base rather than the sides.”
CASO%EJEMPLO%1%%Fig.% 5=% Recortando% el% molde% solamente% desde% la%base%(con%los%incisivos%centrales%en%horizontal)%hasta%que% se% extrae% todo% el% vesGbulo% y% se% produce% un%hueco%en%el%paladar%evitará%el%peligro%de%dañar% los%dientes% respecto% al% recortado% tradicional% así% como%crea%el%molde%más%idóneo%para%la%máquina%de%vacío.%%FigN% 6=% Los% dientes% unitarios% que% ha% resultado%traumaPzados% precisan% ser% examinados%cuidadosamente%mediante% radiograQas.% La% prácPca%más% segura% es% blanquear% este% diente% en% solitario%hasta% que% la% respuesta% del% diente% y% el% máximo%aclaramiento% pueda% ser% determinado% Fig.% 7=% La%cubeta% de% blanqueamiento% de% diente% unitario% no%Pene% reservorio% ni% espaciadores,% y% se% exPende%sobre% la% encía% 1% o% 2% mm% pero% evitando% los%movimientos%del% frenillo.% Los%dientes%que%no%van%a%blanquearse%se%recortan%de% la%cubeta%manteniendo%el% resto%de% la% cubeta% intacta.% Fig.% 8% =% La% cubeta%de%blanqueamiento%de%diente%unitario%se%exPende%más%sobre% el% paladar% que% la% cubeta% tradicional% para%preservar% la% integridad% de% la% cubeta% % cuando% se%recortan% los% dientes% adyacentes.% Los% límites% de% la%cubeta% se% esconden% bajo% las% rugosidades% y% van%dispuestos% sobre% todas% las%áreas%de% tejido.% Fig.% 9%=%Se%ha%obtenido%un%parecido%de%color%razonable%tras%aproximadamente% 8% semanas% de% blanqueamiento%de% diente% unitario.% A% menudo,% los% pacientes%%interrumpen%el% tratamiento% antes%de%que%el% diente%no%haya% llegado%a%alcanzar%su%color%ópPmo,% incluso%aunque%el%resultado%no%sea%el%ideal.%
El diente con terapia endodóncica puede ser tratado desde dentro, desde fuera, o de ambas formas. La decisión de un blanqueamiento externo o interno depende de si sabemos qué ha ocurrido dentro del diente durante la terapia endodóncica y también el tipo de restauración que se ha usado para el sellado de la apertura cameral. El diente puede haber recibido un tratamiento endodóncico satisfactorio y haber sido
restaurado con una restauración lingual de composite que coincida en color, y que no obstante puede haberse oscurecido en los años posteriores (Figura 10). En esta situación, se prefiere el blanqueamiento externo porque la penetración dentro del diente mediante la remoción del composite podría debilitar su estructura (Figura 11). Sin embargo, la decisión de penetrar al interior del diente tratado endodóncicamente depende de si el dentista que lo trata es capaz de proceder al desbridamiento completo del relleno de la cámara pulpar de la terapia endodóncica original, así como de acceder a la altura del cemento y el relleno dentro de la cámara. Blanqueamiento en el consultorio El blanqueamiento en el consultorio es la forma más antigua de blanqueamiento dental. Los intentos de blanquear los dientes se remontan al siglo XIX y el blanqueamiento del diente unitario ha constituido una de las primeras áreas de investigación.45 Se han usado diferentes materiales, pero el peróxido de hidrógeno ha sido históricamente el favorito. El peróxido de hidrógeno a alta concentración podía ser aplicado externa o internamente, y a menudo incluía luz y calor. La técnica clásica de blanqueamiento no vital en el consultorio implicaba el disponer el peróxido de hidrógeno al 35% en el interior de la cámara pulpar e incrementar la reacción química mediante el uso de luz o calor. Sin embargo, esta técnica carece de un control preciso sobre la cantidad de blanqueamiento. De un modo más crítico, cuando se evaluaban los casos de reabsorción externa e interna había cuatro problemas comunes que se detallan:
1. Los dientes habían sufrido un traumatismo. 2. Se usaban altas concentraciones de peróxido. 3. Se utilizaban altas temperaturas para potenciar el blanqueamiento. 4. No se hacía sellado sobre la gutapercha.
Aunque el dentista no puede controlar el trauma, sí puede eliminar las otras tres áreas que están bajo control dental para reducir los eventos de reabsorción y pérdida dentaria.
46 INSIDE DENTISTRY | September 2010 | insidedentistry.net
INSIDE CONTINUING EDUCATION
dark tooth does not get as light as the sur-rounding teeth, then the other teeth are not bleached (Figure 9) and the closest match has been achieved. If the single dark tooth matches the other teeth then, again, the other teeth are not bleached. Only if the single dark tooth gets lighter than the adjacent teeth should they be bleached, and in that case, daytime bleaching in short intervals should be used to avoid getting the adjacent teeth lighter than the single dark bleached tooth. Generally, the patient should be informed that the bleaching time for the single dark tooth is about 8 weeks, although it is highly variable.
Endodontically Treated Anterior TeethIf the dark tooth has already received endodontic therapy, then additional considerations for the discoloration include remaining pulp materials in the pulp chamber, endodontic sealer or filler in the pulp chamber, and dark or leaking restorations in the endodontic access opening, as well as endodontic failure. The type of filler is also impor-tant, as silver points require di!erent considerations from gutta-percha fill-ers. Treatment considerations also may depend on when in the endodontic treatment and subsequent follow-up the tooth was noticed to be dark.
Endodontically treated teeth may be treated from the inside, the outside, or both. The decision for inside or outside depends on a knowledge of what has occurred inside the tooth during the endodontic therapy, as well as the type of restoration used to seal the access opening. The tooth may have received a satisfactory endodontic treatment and
CASE EXAMPLE ONE (5.) Trimming the cast only from the base (with the central incisors horizontal) until the vestibule is removed and a hole oc-curs in the palate will avoid the danger of damaging teeth from traditional trimming as well as create the best cast for use in a vacuum-former. (6.) A single dark tooth from trauma needs to be examined carefully and evalu-ated with a radiograph. The safest approach is to bleach this tooth alone until the tooth’s response and maximum lightening can be determined. (7.) The “single-tooth” bleaching tray has no reservoir or spacers and extends onto the gingiva 1 mm to 2-mm, but avoids frenum movements. The teeth not to be bleached have the tooth molds removed from the tray while maintaining the intact tray. (8.) The single-tooth bleaching tray extended further onto the palate than the traditional tray to preserve the tray integrity when the adjacent teeth molds were removed from the tray. The tray edges are hidden behind rugae and go onto the tissue in all areas. (9.) A reasonable match was obtained from about 8 weeks of single-tooth bleaching. Often patients discontinue treatment when the single tooth is no longer a mismatch, even if the outcome is not ideal. CASE EXAMPLE TWO (10.) This root canal has been successful for 30 years, but the tooth has become slightly discolored. There is no reason from the radiograph to re-enter the pulp chamber, as this will further weaken the tooth. External bleaching by a single-tooth bleaching tray is indicated (11.) The 10% carb-amide peroxide bleaching material was applied externally with the single-tooth bleaching tray nightly until the shade of the endodontically treated tooth returned to match the adjacent teeth. Should the tooth re-darken again, the process can be repeated without danger to the tooth. Figure 10 and Figure 11 courtesy of Meigan Johnson.
FIG. 7 FIG. 8
FIG. 5 FIG. 6
FIG. 9
been subsequently restored with an ac-ceptable lingual composite that matched the tooth color. However, in subsequent years, the tooth may have discolored (Figure 10). In this situation, the deci-sion for bleaching favors external bleach-ing, because going inside the tooth to remove the composite will weaken the tooth (Figure 11). However, the choice not to go inside the endodontic tooth depends on whether the treating dentist is aware of the extent to which the pulp chamber was debrided during endodon-tic therapy, as well as the height in the chamber of the cement and filler.
In-O!ce BleachingIn-o"ce bleaching is the oldest form of bleaching. Attempts to bleach single dark teeth date back to the 1800s, and bleaching a single dark tooth was one of the first bleaching research areas.45 A number of materials have been used, but hydrogen peroxide has been the historic favorite. The high concentra-tion of hydrogen peroxide could be applied externally or internally, and often involved heat and light. The classic non-vital in-o"ce bleaching technique involved the placement of 35% hydrogen peroxide into the pulp chamber, and increasing the chemi-cal reaction by the use of heat or light. However, this technique lacks precise control as to the amount of lightening. More critically, when cases of external or internal resorption were evaluated, there were four common concerns list-ed: 1) teeth had received trauma; 2) high concentrations of peroxide were used; 3) high heat was used to enhance the bleaching, and 4) there was no seal over the gutta-percha. Although the dentist cannot control the trauma, elimination of the other three areas under dental control should be done to lessen the chances of resorption and loss of the tooth. Other possibilities for resorp-tion include the fact that 10% of teeth do not have a connection between the enamel and cementum, with possible percolation of hydrogen peroxide into the surrounding areas, lowering the pH. Using a bleaching product with a higher pH or a salivary catalase are attempts to reduce resorption issues.
Walking Bleach TechniqueThe change in in-o"ce bleaching led to the next step of “walking bleaching.” In this technique, the gutta-percha was removed 2 mm below the CEJ and a
FIG. 10 FIG. 11
“One challenge infabrication of the single-tooth or regular bleaching tray is trimming the cast without abrading either the teeth or thegingiva. This outcome is accomplishedby trimming the cast from the base rather than the sides.”
CASO%EJEMPLO%2%FIG.%10%=%La%endodoncia%ha%funcionado%con%éxito%durante%30%años%pero%el%diente%se%ha%decolorado%ligeramente.%A%la%vista%de%la%radiograIa,%no%hay% razón% para% una% reNentrada% en% la% cámara% pulpar% porque% ello%debilitaría%más%el%diente.%Está%indicada%la%cubeta%de%blanqueamiento%de%diente% unitario.% Fig.% 11% =% El% peróxido% de% carbamida% al% 10%% se% aplica%externamente% con% la% cubeta% de% blanqueamiento% de% diente% unitario%uTlizada% por% la% noche% hasta% que% el% color% del% diente% tratado%endodóncicamente%coincida%con%el%color%de%los%adyacentes.%Si%el%diente%se%vuelve%a%decolorar%puede%repeTrse%el%procedimiento%sin%peligro%de%dañar%el%diente.%(FigN10%y%11%son%cortesía%de%Meigan%Johnson)%
Otras circunstancia a tener en cuenta respecto a la reabsorción incluye el hecho de que el 10% de los dientes no tienen un buen acoplamiento entre el esmalte y el cemento, y puede producirse la percolación del peróxido de hidrógeno en los tejidos adyacentes y disminuir el pH. Se intenta reducir los fenómenos de reabsorción utilizando productos con un pH más elevado, o con catalasa salival. Técnica de blanqueamiento ambulatorio La evolución en la técnica de blanqueamiento en el consultorio condujo a la técnica de blanqueamiento ambulatorio. En esta técnica se extirpaba la gutapercha 2 mm por debajo del nivel de la línea amelocementaria y se ponía una base para aislar el sellado endodóncico del espacio de la cámara pulpar. Luego, inicialmente se aplicaba un peróxido de hidrógeno de alta concentración, se sellaba, y el paciente abandonaba el consultorio mientras el peróxido de hidrógeno oxidaba la decoloración. El tratamiento consigue el éxito después de 1 a 6 aplicaciones por semana. La cuestión es que las altas concentraciones de peróxido de hidrógeno pueden ser cáusticas tanto para el dentista como para el paciente. Más tarde, esta técnica evolucionó incorporando al peróxido de hidrógeno el perborato de sodio formando una mezcla que era más fácil de manipular. El perborato de sodio se disocia para generar alrededor de un 3% de solución de peróxido de hidrógeno. Finalmente se eliminó la alta concentración de peróxido de hidrógeno y se uso únicamente perborato de sodio. La técnica de blanqueamiento interno continuaba añadiendo catalasa para neutralizar el peróxido de hidrógeno y elevar el pH a todo lo largo del diente. Con cualquier tratamiento blanqueador debe darse tiempo para la estabilización del tono y la disipación del oxígeno del diente. Si se inicia la restauración inmediatamente después del blanqueamiento hay un 25% de reducción de las fuerzas de adhesión debido a la inhibición del fraguado del composite por el oxígeno remanente, resultando en un acortamiento de los tags o indentaciones del material en el esmalte. La estabilización de color y el retorno de la adhesión a la normalidad ocurre aproximadamente en dos semanas. Más tarde, se encontró que el peróxido de carbamida era tan efectivo como el perborato de sodio para el blanqueamiento interno, a la misma concentración con el beneficio adicional de que causa una elevación del pH que puede ser beneficioso para evitar las reabsorciones. Una solución de peróxido de carbamida al 10% es equivalente a peróxido de hidrógeno al 3, 5% y 6,5% de urea. Es la urea la que causa el incremento del pH, a niveles de 8 dentro de los 5 primeros minutos de aplicación, algo que no se consigue con las presentaciones que solo contienen peróxido de hidrógeno. Además, el peróxido de carbamida produce una lenta liberación de peróxido y éste es activo durante más tiempo que en las formulaciones de peróxido de hidrógeno en solitario. Esta liberación retardada de peróxido parece que favorece las tasas de cambio de color.
Debido a que el trauma es uno de los iniciadores de la reabsorción, su influencia no puede ser totalmente eliminada y en los dientes que no han sido blanqueados cabe la posibilidad de que puedan comenzar un proceso de reabsorción. Los dientes que han sufrido un traumatismo deben ser revisados radiográficamente cada uno o dos años tanto si han sido blanqueados como si no. Blanqueamiento interno Cuando realizamos blanqueamiento interno en un diente que ha sido sometido a terapia endodóncica es importante la limpieza del interior de la cámara pulpar (Figura 12). A menudo, cuando se hace una endodoncia terapéutica debido a un traumatismo la cámara pulpar es amplia y con los cuernos pulpares elevados, en ese caso, la apertura cameral hacia el ápice puede no haber incluido el desbridamiento total de la cámara pulpar (Figura 13). El dentista que realice la restauración debe abrir suficientemente el acceso extendiéndose tanto a nivel incisal como lateral de la cámara pulpar. Con frecuencia, la remoción del tejido cameral remanente modificará de forma significativa el color del diente incluso antes de que el blanqueamiento haya empezado (Figura 14).
48 INSIDE DENTISTRY | September 2010 | insidedentistry.net
INSIDE CONTINUING EDUCATION
base was applied to seal the endodontic filling material from the pulp chamber. Then, initially, a high concentration of hydrogen peroxide was applied, sealed, and the patient “walked out of the o!ce” while the hydrogen peroxide oxidized the discoloration. This treatment took anywhere from 1 to 6 weekly applica-tions. The challenge was that the high concentration of hy drogen peroxide could be caustic to either the dentist or the patient. Later, this technique evolved into mixing the hydrogen per-oxide with sodium perborate to form a mixture that was easier to handle. Sodium perborate breaks down into about a 3% solution of hydrogen per-oxide. Finally, the high concentration of hydrogen peroxide was eliminated and sodium perborate alone was used. Internal bleaching treatment was fol-lowed by the use of a catalase to neu-tralize the hydrogen peroxide and el-evate the pH around the tooth. With any bleaching treatment, time should be allowed for the shade to stabilize and the oxygen to dissipate from the tooth. If bonding is initiated immediately af-ter bleaching, there is a 25% reduction in bond strengths due to the inhibition of the composite set from the oxygen in the tooth, resulting in shorter enamel tags. It generally takes about 2 weeks or longer for the shade to stabilize and the bond strength to return to normal.
Later, 10% carbamide peroxide was found to be equally as e"ective as so-dium perborate for internal bleaching, at the same concentration, with the additional benefit of causing a rise in pH, which may be beneficial to avoid resorption. A 10% solution of carb-amide peroxide is equivalent to 3.5% hydrogen peroxide and 6.5% urea. It is the urea that causes the increase in pH within 5 minutes after application to a level above 8, which cannot be ac-complished with hydrogen peroxide alone. Also, the carbamide peroxide has a slower peroxide release and is active longer than hydrogen peroxide. This slower application of peroxide seems to favor the rate of color change. Because trauma is one of the initia-tors of resorption, that event cannot be totally eliminated. Even teeth that have not been bleached can begin to have resorption, so there is always that possibility. Traumatized teeth should have recall radiographs taken every 1 to 2 years, whether they have been bleached or not.
Inside BleachingWhen performing internal bleaching on a non-vital tooth that has received endodontic therapy, it is important to clean out the inside of the pulp cham-ber (Figure 12). Often, when endodon-tic therapy is performed because of trauma, the pulp chamber is large, with high pulp horns. The access opening to the apex may not include debride-ment of the chamber (Figure 13). The restorative dentist should open the access opening enough to access both the incisal extent as well as the lateral extent of the pulp chamber. Often, re-moval of the remaining pulp chamber will significantly alter the color of the tooth, even before the bleaching has begun (Figure 14).
Inside-Outside Closed BleachingOne of the best options for an endodon-tically treated tooth is to use both the inside and outside techniques in combi-nation. Entering the inside of the tooth will allow removal of any pulp tissue, filler, or cement sealer, as well as discol-ored restorations in the chamber. The classic walking-bleaching treatment is performed as described above (Figure 15 and Figure 16), then the tooth is temporarily sealed while a single-tooth bleaching tray is fabricated. Bleaching continues at home externally using the single-tooth tray approach until the sin-gle dark tooth has reached its maximum lightness (Figure 17). Then the patient waits 2 weeks for the shade to stabilize and the bond strengths to return to normal. Upon return to the dentist, a comparison of the single tooth is made to the adjacent teeth. If the endodon-tically treated tooth remains slightly darker than the remaining teeth, an opaque stark-white composite is used internally to fill the pulp chamber and provide an additional slight lightening of the tooth (Figure 18). The final ori-fice is closed with the appropriate color-matched composite to the external por-tion of the tooth. Some clinicians prefer to use a resin-modified glass ionomer internally to improve the bond to dentin, followed by the traditional composite restoration to close the opening. This approach of both inside and outside bleaching with a closed pulp chamber gives the benefits of both techniques. The inside bleaching segment allows the tooth to be cleaned as well as tem-pers the final color with a composite
FIG. 13FIG. 12
FIG. 14
FIG. 16
FIG. 15
FIG. 17
CASE EXAMPLE THREE (12.) The initial examination and radiograph determined that the dark lateral incisor was abscessed. After endodon-tic therapy, the tooth was then ready for bleaching. Had bleaching been performed without the radiograph, the abscess would have remained untreated and further damaged the tooth. (13.) The endodontic access opening should be enlarged until it can be certain that all the remaining brown pulp tissue has been removed from the lateral walls of the pulp chamber as well as the incisal extent. Pulps that became necrotic when the tooth was young often have pulp chambers much larger than the endodontic access opening. (14.) Even before bleaching the tooth, the re-moval of the brown necrotic pulp remnants and dental materials makes the tooth much lighter. This occurrence demonstrates how the materials inside the tooth a!ect the color of the outside. (15.) For internal bleaching, the gutta-percha should be removed 2 mm below the CEJ. (16.) Once the gut-ta-percha has been removed to the appropriate depth and from the walls of the pulp chamber, the endodontic filler is sealed from the pulp chamber with a resin-modified glass ionomer. Etching is not required for bleaching. (17.)The patient may bleach externally (as well as internally) with a full tray rather than a "single-tooth tray" to lighten all the teeth or because there are crowns that will not change color. To identify the dark tooth for ad-ditional treatment, an “X” is placed on the tooth mold for the placement of the bleaching material. If the tray is to be worn during the day rather than at night, the “X” should be placed on the lingual. (18.) After the tooth being bleached has reached its maximum lightening, the bleaching process should be stopped for 2 weeks to allow the shade to stabilize and the bond strengths to return to normal. Then an opaque whiter composite can be placed in the chamber if needed to further harmonize the tooth color.
FIG. 18
CASO%EJEMPLO%3%Fig.%12%=%El%examen%inicial%y%la%radiogra>a%determinaron%que%el% incisivo% lateral% oscurecido% estaba% abscesificado.% Tras% la%terapia% endodóncica,% el% diente% estará% entonces% preparado%para% el% blanqueamiento.% Si% se% hubiese% hecho% el%blanqueamiento% sin% radiogra>a,% el% absceso% quedaría% sin%tratar%con%daño%adicional%para%el%diente.%Fig.%13%=%El%acceso%endodónico% debe% agrandarse% hasta% estar% seguros% de% que%todo% el% tejido% pulpar% remanente% ha% sido% exOrpado% de% las%paredes%laterales%de%la%cámara%pulpar%así%como%de%la%porción%incisal.%En%las%pulpas%que%se%necrosaron%cuando%el%diente%era%joven% la% cámara% pulpar% es% mucho% mayor% que% la% apertura%endodóncica.Fig.% 14% =% % % % Incluso% antes% de% blanquear% el%diente,% la% exOrpación% de% los% remanentes% necróOcos%marrones%de%la%pulpa%y%de%los%materiales%dentales%hacen%que%el%diente%aparezca%mucho%más%claro.%Este%hecho%demuestra%en%qué%medida%los%materiales%dentro%del%diente%afectan%a%la%apariencia% de% color% externa.% Fig.% 15% =% % Para% el%blanqueamiento% interno% la% gutapercha% debe% exOrparse% a% 2%mm%por%debajo%de%la%unión%amelocementaria.%Fig.%16%=%%Una%vez%que%se%ha%extraído%la%gutapercha%a%la%altura%adecuada%y%de% todas% las% paredes% de% cámara% pulpar,% el% relleno%endodóncico% se% sella% desde% la% cámara% pulpar% con% un%ionómero%de%vidrio%modificado%con%resina.%El%grabado%no%se%requiere% para% el% blanqueamiento.% Fig.% 17% =% El% propio%paciente% puede% blanquear% externamente% (así% como%internamente)%con%una%cubeta%completa,%mejor%que%con%una%“cubeta%de%diente%único”%para%blanquear%todos%los%dientes%o%quizá%porque%en%su%boca%Oene%coronas%que%no%cambiarán%de%color.% %Para% idenOficar%el%diente%oscurecido%en% la%cubeta%se%pondrá%una%X%en%el%diente%del%molde%para%marcar%la%posición%donde%se%dispondrá%el%material%blanqueador.%Si%la%cubeta%es%para%ser%usada%durante%el%día%y%no%durante%la%noche%la%X%se%marcará%en%lingual.%Fig.%18%=%Después%de%que%el%diente%se%ha%blanqueado% hasta% alcanzar% su% máxima% clarificación,% el%proceso% de% blanqueamiento% ha% de% pararse% durante% 2%semanas% para% permiOr% la% estabilización% de% los% maOces% de%color%y% la%normalización%de% las% fuerzas%de%adhesión.% Luego,%puede% ponerse% en% la% cámara% un% composite% opaquer% si% se%necesita%una%armonización%de%color%adicional.%
Blanqueamiento ambulatorio externo e interno Una de las mejores opciones para un diente tratado mediante endodoncia es usar las técnicas externa e interna en combinación. El acceso al interior del diente permitirá la remoción de cualquier resto pulpar, rellenador o cemento sellante, así como restauraciones decoloradas dentro de la cámara. El tratamiento ambulatorio clásico se realiza como se describía antes (Figuras 15 y 16), y a continuación se sella el diente temporalmente mientras se fabrica la cubeta. El blanqueamiento externo continua en el domicilio sondeando con la cubeta de diente unitario los máximos niveles de aclaramiento del diente oscurecido (Figura 17). Luego el paciente espera dos semanas para que la estabilización del tono y de las fuerzas de adhesión retornen a la normalidad. En cuanto vuelva al dentista se hará una comparación entre el diente tratado y los adyacentes. Si el diente se mantiene levemente más oscuro que el resto se utiliza un composite opaquer ultrablanco para rellenar la cámara pulpar y proporcionar un ligero aclaramiento adicional al diente (Figura 18). El orificio se rellena finalmente con el composite del color del diente en su porción más superficial. Algunos clínicos prefieren el uso de ionómeros modificados con resinas en el interior para mejorar la adhesión a la dentina, seguido de un composite convencional de restauración para cerrar la apertura. Este intento de blanqueamiento tanto interno-‐externo con una cámara pulpar cerrada aporta los beneficios de ambas técnicas. La parte dedicada al blanqueamiento interno permite que el diente esté limpio y al mismo tiempo calibra el color final con la restauración composite, mientras que el periodo de blanqueamiento interno permite al paciente blanquear durante el tiempo necesario para obtener el máximo aclaramiento del diente hasta que regresa al consultorio (Figuras 19 y 20).
Debido a que ya disponemos del molde con el que fabricamos la cubeta de diente unitario, y en caso de que éste haya blanqueado más que el resto, se puede fabricar una nueva cubeta para que el paciente la use diariamente y hasta alcanzar el color deseado semejante al diente que fue tratado. El tiempo medio de tratamiento para el diente unitario parece ser de 8 semanas, aunque existe un amplio rango de intervalos de
tiempo. Mientras el peróxido de carbamida al 10% se utiliza generalmente en los tratamientos nocturnos, se pueden usar concentraciones más elevadas una vez que se ha determinado que la sensibilidad no es un problema.
INSIDE CONTINUING EDUCATION
restoration, while the outside bleaching segment allows the patient to bleach as long as necessary to obtain the maxi-mum whitening of the tooth without returning to the o!ce (Figure 19 and Figure 20). Because a cast already ex-ists for the single-tooth tray, should the single tooth get lighter than adjacent teeth, a new bleaching tray can be fab-ricated and the patient can use it for day wear to titrate the color to a final match. The average treatment time for single dark teeth seems to be 8 weeks, although there is a wide range of treat-ment times. While 10% carbamide per-oxide is generally used for traditional overnight treatment, higher concentra-tions may be used once it is determined that sensitivity is not a problem.
Inside-Outside Open BleachingIn special patients and situations, the dentist may chose to perform inside and outside bleaching while leaving the ac-cess opening unrestored. In this situa-tion, the patient injects carbamide per-oxide into the pulp chamber and the tray, then seats the tray in the mouth to pro-tect the opening. While this may shorten treatment time due to the continued ap-plication of fresh bleaching material, it is essential that the patient be able to perform their part, and also return to the o!ce to have the opening closed. While the tooth will not get any tooth decay during the bleaching process due to the increase in pH a"orded by the carbamide peroxide,46 there is the dan-ger that the patient may cease bleach-ing but not return in a timely fashion to have the orifice sealed. If the o!ce is not equipped to fabricate the additional
single-tooth tray, then the standard re-placement of the internal carbamide peroxide is performed weekly, taking 1 to 6 o!ce visits for completion. A pro-visional restoration maintains the seal, and the patient is instructed to call the o!ce immediately if occlusion or food disrupts the provisional seal.
Bleaching or Crown DecisionsThe question is often asked why the an-terior endodontically treated tooth is not crowned today as it once was in the past. One reason for the resurgence of bleaching single anterior teeth is that the research has shown that while pos-terior teeth that have received a root ca-nal should be crowned, anterior teeth should only be crowned if they needed a crown regardless of the endodontic therapy. The reason is because the single greatest predictor of survival of an end-odontically treated tooth is the amount of remaining dentin. If an intact anterior tooth has a root canal, the external enam-el and dentin is still intact. Preparing the tooth for a crown after the endodontic treatment removes the remaining den-tin and results in a premature loss of the tooth. Research has also shown that the post does not strengthen the tooth, and cannot compensate for the loss of dentin. Hence, the tooth has a better prognosis to be bleached and restored with composite than to receive a post, core, and crown.
Conclusion The single dark tooth is an esthetic challenge regardless of the treatment approach. Bleaching the single tooth alone is the safest, most conservative approach to determining the response of the single tooth before changing the
adjacent tooth colors. A “single-tooth” bleaching tray is the tray of choice for external bleaching. Single dark teeth with calcific metamorphosis should not be treated endodontically unless there are clinical symptoms of pain or radio-graphic evidence of an abscess.
For internal bleaching of an end-odontically treated tooth, a “walking bleach” approach using 10% carbamide peroxide internally seems to a"ord the safest approach over previous tra-ditional methods. The combination of one internal bleaching appointment to debride the pulp chamber, followed by tray bleaching with a single-tooth tray or full non-scalloped, no reservoir tray pro-vides the flexibility of unlimited time of treatment without incurring significant in-o!ce charges. Additionally, waiting 2 weeks after bleaching for the shade to stabilize and the bond strengths to re-turn to normal and then using internal composite bonding can harmonize final shade discrepancies. Regardless of the technique used for bleaching, a relapse is possible in 1 to 3 years, and is generally best addressed by outside bleaching in a single-tooth tray with 10% carbamide peroxide to re-bleach the tooth until it matches the surrounding teeth.
References1. Glendor U, Halling A, Andersson L, Eilert-Petersson E. Incidence of traumatic tooth injuries in the county of Västmauland, Sweden. Swed Dent J. 1996;20:15-28.2. Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 4th ed. Oxford, England: Blackwell Munskgaard; 2007.3. Davis GT, Knott SC. Dental trauma in Australia. Aust Dent J. 1984;29:217-221.4. Brunner F, Krasti G, Filippi A. Dental trauma in adults in Switzerland. Dental Traumatol. 2009;25:181-184.5. Glendor U. Epidemiology of traumatic dental injuries—a 12 year review of the literature. Dent Traumatol. 2008;24:603-609.6. Kaste LM, Gift HC, Bhat M, Swango PA. Prevalence of incisor trauma in persons 6-50 years of age: United States, 1988-1991. J Dent Res. 1996;75:696-705.7. Petti S, Tarsitani G, Arcadi P, et al. The preva-lence of anterior tooth trauma in children 6 to 11 years old. Minerva Stomatol. 1996;45:213-218.8. Rocha MJ, Cardoso M. Traumatized perma-nent teeth in Brazilian children at the Federal University of Santa Catarina, Brazil. Dent Traumatol. 2001;17:245-249.9. Flores MT. Traumatic injuries in the primary dentition. Dent Traumatol. 2002;18:287-298.
10. Hedegård B, Stalhane I. A study of trauma-tized permanent teeth in children aged 7-15 years. Part 1. Swed Dent J. 1973;66:431-450.11. Gelbier S. Injured anterior teeth in chil-dren. A preliminary discussion. Br Dent J. 1967;123:331-335.12. Davis GT, Knott SC. Dental trauma in Australia. Aust Dent J. 1984;29:217-221.13. Kramer PF, Zembruski C, Ferreira SH, Feldens CA. Traumatic dental injuries in Brazilian preschool children. Dent Traumatol. 2003;19:299-303.14. Skaare AB, Jacobsen I. Dental injuries in Norwegians aged 7-18 years. Dent Traumatol. 2003;19:67-71.15. Hosnik A. Emergency treatment of dentoal-veolar trauma. Phys Sports Med. 2004;32(9):1-10.16. Onetto JE, Flores MT, Garbarino ML. Dental trauma in children and adolescents in Valparaiso, Chile. Endo Dent Traumatol. 1999;10:223-227.17. Cornwell H. Dental trauma due to sport in the pediatric patient. Calif Dent Assoc J. 2005; 33(6)457-461.18. Zerman N, Caralleri G. Traumatic injuries to permanent incisors. Endod Dent Traumatol. 1993;9:61-64.19. Skaare AB, Jacabsen I. Etiological factors related to dental injuries in Norwegians aged 7-18 years. Dent Traumatol. 2003;19:304-8.20. Gassner R, Bösch R, Tulit, Emskoff R. Prevalence of dental trauma in 6000 patients with facial injuries: Implications for treatment. Oral Surg Oral Med Oral Path Oral Radiol Endod. 1999;87:27-33.21. Brunner F, Krasti G, Filippi A. Dental trauma in adults in Switzerland. Dent Traumatol. 2009;25:181-184.22. Promoting oral health: interventions for preventing dental caries, oral and pharyngeal cancers and sports related craniofacial injuries: a report on recommendations of the Task Force on Community Preventive services. MMWR. 2001;50(RR21):1-13.23. Tuli T, Hachl O, Hohlrieder M, et al. Dentofacial trauma in sports accidents. Gen Dent. 2002;50(3):274-279.24. Needleman HL. Orofacial trauma in child abuse: types, prevalence, management and the dental profession. Pediatr Dent. 1986;8:71-80.25. Dimitroulis G, Eyre J. A 7-year review of maxillofacial trauma in a central London hos-pital. Br Dent J. 1991;170:300-302.26. Perkeentupa U, Laukkanen P, Veijola J, et al. Increased lifetime prevalence of dental trauma is associated with previous non-dental injuries, mental distress and high alcohol consumption. Dent Traumatol. 2001;17:10-16.27. Feiglin B. Dental pulp response to traumatic injuries—a retrospective analysis with case reports. Endod Dent Traumatol. 1996;12:1-8.28. Amir FA, Gutmann JL, Witherspoon DE.
FIG. 19
CASE EXAMPLE FOUR ((19.) The endodontically treated canine is much darker than the adjacent teeth, but in this less-esthetic area, a full tray was used to lighten all the teeth. The canine was bleached internally with one treatment and externally to completion. (20.) After 3 weeks of external bleaching with 10% carbamide peroxide at night, the adjacent teeth reached their maximum lightness. While the other teeth are slightly lighter than the canine, the color match was much closer and pleasing to the patient.
FIG. 20
50 INSIDE DENTISTRY | September 2010 | insidedentistry.net
CASO%EJEMPLO%4%Fig.%19%=%El%canino%tratado%con%endodoncia%es%mucho%más%oscuro%que%los%dientes%adyacentes,%pero%en%esta%zona%menos%estéGca%se%uGliza%una%cubeta% completa% para% blanquear% todos% los% dientes.% El% canino%internamente% en% una% sesión,% y% externamente% hasta% el% final% del%tratamiento.% Fig.% 20% =% Después% de% 3% semanas% de% blanqueamiento%externo% nocturno% con% peróxido% de% carbamida% al% 10%% los% dientes%adyacentes% alcanzaron% su% máxima% clarificación.% Aunque% los% otros%dientes% son% ligeramente%más% claros% que% el% canino,% % el% color% combina%mejor%y%el%paciente%está%saGsfecho.%
Blanqueamiento interno y externo abierto En determinados pacientes y situaciones, el dentista puede optar por realizar un blanqueamiento externo-‐interno mientras deja abierto el acceso sin restauración. En esta circunstancia, el paciente inyecta peróxido de carbamida dentro de la cámara pulpar y de la cubeta, luego asienta la cubeta en la boca para proteger la apertura. Aunque esta técnica acorta el tiempo de tratamiento debido a la aplicación continua de material nuevo, es esencial que el paciente sea capaz de realizar su parte y también volver al consultorio para cerrar la apertura. A pesar de que el diente no sufrirá ninguna caries durante el proceso de blanqueamiento debido al incremento de pH conseguido por el peróxido de carbamida,46 existe el peligro de que el paciente abandone el tratamiento blanqueador pero no regrese a la consulta en el momento más adecuado para sellar el orificio. Si el consultorio no está equipado para fabricar la cubeta tradicional de diente unitario se procederá al reemplazo clásico de peróxido de carbamida interno realizado semanalmente, lo que ocupará de 1 a 6 visitas para completar el tratamiento. En este caso, se mantiene el sellado con una restauración provisional y se instruye al paciente para que llame al consultorio inmediatamente si la oclusión o el alimento desmoronan la restauración provisional. Toma de decisiones: Blanqueamiento o corona La cuestión que se plantea actualmente es por qué un diente anterior tratado endodóncicamente no se trata con corona de recubrimiento como se hacía en le pasado. Una de las razones del resurgimiento del blanqueamiento del diente unitario del sector anterior es que la investigación ha demostrado que el diente posterior tratado con endodoncia debe ser tratado con corona, los dientes anteriores solamente deben ser enfundados si necesitan una corona con independencia de la terapia endodóncica. La razón es que el único factor que predice la supervivencia del diente endodonciado es la cantidad de dentina remanente. Si un diente del sector anterior intacto sufre una endodoncia, la dentina y el esmalte exterior permanecen igualmente intactos. Si hacemos una preparación para corona extirpamos la dentina remanente y se producirá una pérdida prematura del diente. Los estudios también han demostrado que los postes intrarradiculares no refuerzan el diente y no compensan la pérdida de dentina. Por tanto, el diente tiene mejor pronóstico si se blanquea y se restaura con composite que si recibe un poste, reconstrucción y una corona. Conclusión El diente unitario oscurecido es un reto estético independientemente de la estrategia de tratamiento. Blanquear solamente el diente oscurecido es el intento más conservador y seguro para determinar su respuesta antes de cambiar el color de los dientes adyacentes. La cubeta de blanqueamiento de diente unitario es la cubeta de elección para el blanqueamiento externo. El diente único oscurecido que sufre metamorfosis calcificante no debe ser tratado con endodoncia a menos que haya síntomas clínicos de dolor o evidencia radiográfica de un absceso.
Para el blanqueamiento interno de un diente tratado endodóncicamente, un intento de blanqueamiento ambulatorio utilizando peróxido de carbamida al 10% internamente parece ofrecer el método más seguro frente a métodos tradicionales previos. La combinación de una cita de blanqueamiento interno para desbridar la cámara pulpar, seguido por una cubeta de blanqueamiento de diente unitario, o una cubeta completa no festoneada y sin reservorio, proporciona la flexibilidad del tiempo ilimitado de tratamiento sin incurrir en gastos de consulta significativos. Adicionalmente, esperar 2 semanas después del blanqueamiento para estabilizar el tono y la normalidad de las fuerzas de adhesión y luego, utilizando una restauración de composite se pueden armonizar discrepancias finales de color. Cualquiera que sea la técnica utilizada para blanquear, es posible una recidiva entre 1 y 3 años después, y esta es habitualmente mejor aceptada si se usa una técnica ambulatoria de cubeta de diente unitario con peróxido de carbamida al 10% que vuelva a blanquear el diente hasta que coincida con el color de los dientes adyacentes. ,
BIBLIOGRAFÍA 1. Glendor U, Halling A, Andersson L, Eilert-‐Petersson e. incidence of traumatic
tooth injuries in the county of Västmauland, sweden. Swed Dent J. 1996;20:15-‐28.
2. Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 4th ed. Oxford, england: Blackwell Munskgaard; 2007.
3. Davis Gt, Knott SC. Dental trauma in Australia. Aust Dent J. 1984;29:217-‐221.
4. BrunnerF,KrastiG,FilippiA. Dental trauma in adults in Switzerland. Dental Traumatol. 2009;25:181-‐184.
5. Glendor U. Epidemiology of traumatic dental injuries—a 12 year review of the literature. Dent Traumatol. 2008;24:603-‐609.
6. Kaste LM, Gift HC, Bhat M, Swango PA. Prevalence of incisor trauma in persons 6-‐50 years of age: United states, 1988-‐1991. J Dent Res. 1996;75:696-‐705.
7. Petti S, Tarsitani G, Arcadi P, et al. The prevalence of anterior tooth trauma in children 6 to 11 years old. Minerva Stomatol. 1996;45:213-‐218.
8. Rocha MJ, Cardoso M. Traumatized permaent teeth in Brazilian children at the Federal University of Santa Catarina, Brazil. Dent Traumatol. 2001;17:245-‐249.
9. Flores MT. Traumatic injuries in the primary dentition. Dent Traumatol. 2002;18:287-‐298.
10. Hedegård B, Stalhane I. A study of traumatized permanent teeth in children aged 7-‐15 years. Part 1. Swed Dent J. 1973;66:431-‐450.
11. Gelbier S. Injured anterior teeth in children. A preliminary discussion. Br Dent J. 1967;123:331-‐335.
12. Davis Gt, Knott SC. Dental trauma in Australia. Aust Dent J. 1984;29:217-‐221.
13. Kramer PF, Zembruski C, Ferreira SH, Feldens CA. Traumatic dental injuries in Brazilian preschool children. Dent Traumatol. 2003;19:299-‐303.
14. Skaare AB, Jacobsen I. Dental injuries in norwegians aged 7-‐18 years. Dent Traumatol. 2003;19:67-‐71.
15. Hosnik A. Emergency treatment of dentoalveolar trauma. Phys Sports Med. 2004;32(9):1-‐10.
16. Onetto JE, Flores MT, Garbarino ML. Dental trauma in children and adolescents in Valparaiso, Chile. Endo Dent Traumatol. 1999;10:223-‐227.
17. Cornwell H. Dental trauma due to sport in the pediatric patient. Calif Dent Assoc J. 2005; 33(6)457-‐461.
18. Zerman n, Caralleri G. Traumatic injuries to permanent incisors. Endod Dent Traumatol. 1993;9:61-‐64.
19. Skaare AB, Jacabsen I. Etiological factors related to dental injuries in norwegians aged 7-‐18 years. Dent Traumatol. 2003;19:304-‐8.
20. Gassner R, Bösch R, Tulit, Emskoff r. Prevalence of dental trauma in 6000 patients with facial injuries: implications for treatment. Oral Surg Oral Med Oral Path Oral Radiol Endod. 1999;87:27-‐33.
21. BrunnerF,KrastiG,FilippiA. Dental trauma in adults in Switzerland. Dent Traumatol. 2009;25:181-‐184.
22. Promoting oral health: interventions for preventing dental caries, oral and pharyngeal cancers and sports related craniofacial injuries: a report on recommendations of the task Force on Community Preventive services. MMWR. 2001;50(rr21):1-‐13.
23. Tuli T, Hachl O, Hohlrieder M, et al. Dentofacial trauma in sports accidents. Gen Dent. 2002;50(3):274-‐279.
24. Needleman HL. Orofacial trauma in child abuse: types, prevalence, management and the dental profession. Pediatr Dent. 1986;8:71-‐80.
25. Dimitroulis G, Eyre J. A 7-‐year review of maxillofacial trauma in a central London Hospital. Br Dent J. 1991;170:300-‐302.
26. Perkeentupa U, Laukkanen P, Veijola J, et al. Increased lifetime prevalence of dental trauma is associated with previous non-‐dental injuries, mental distress and high alcohol consumption. Dent Traumatol. 2001;17:10-‐16.
27. FeiglinB. Dental pulp response to traumatic injuries -‐a retrospective analysis with case reports. Endod Dent Traumatol. 1996;12:1-‐8.
28. Amir FA, Gutmann JL, Witherspoon DE. Calcific metamorphosis: a challenge in endodontic diagnosis and treatment. Quintessence Int. 2001;32:447-‐455.
29. Andreasen J. Luxation of permanent teeth due to trauma. Scand J Dent Res. 1970;78:273-‐286.
30. Andreasen FM, Yu Z, Thomsen BL, Andersen PK.. The occurrence of pulp canal obliteration af-‐ ter luxation injuries in the permanent dentition. Endod Dent Traumatol. 1987;3:103-‐15.
31. Robertson A, Andreasen FM, Bergenholtz G, et al. Incidence of pulp necrosis subsequent to pulp canal obliteration from trauma to permanent incisors. J Endod. 1996;22:557-‐606.
32. Kuyk JK, Walton RE. Comparison of the radiographic appearance of root canal size to its actual diameter. J Endod. 1990;16(11):528-‐533.
33. Piatteli A. Generalized “complete” calcific degeneration or pulp obliteration. Endod Dent Traumatol. 1992;8:259-‐263.
34. Jacobsen I, Kerekes K. Long term prognosis of traumatized permanent anterior teeth showing calcifying processes in the pulp cavity. Scand J Dent Res. 1977;85(7):588-‐598.
35. Holcomb JB, Gregory WB Jr. Calcific metamorphosis of the pulp; its incidence and treatment. Oral Surg Oral Med Oral Pathol. 1967;24(6):825-‐830.
36. Netto JJ, Gondim JO, deCarralho FM, Giro EM. Longitudinal clinical and radiographic evaluations of severely intruded permanent incisors in a pediatric population. Dent Traumatol. 2009;25(5):510-‐514.
37. Robertson A. A retrospective evaluation of patients with uncomplicated crown fractures and luxation injuries. Endod Dent Traumatol. 1998;14:245-‐256.
38. Andreasen FM, Andreasen JO, Bayer T. Prognosis of root fractured permanent incisors: prediction of healing modalities. Endod Dent Traumatol. 1989;5:11-‐22.
39. Schindler WG, Gullickson DC. Rationale for the management of calcific metamorphosis secondary to traumatic injuries. J Endod. 1988;14(8):408-‐412.
40. Smith JW. Calcific metamorphosis: a treatment dilemma. Oral Surg Oral Med Oral Pathol. 1982;54(4):441-‐444.
41. Akertblon A, Hasselgren G. The prognosis for endodontic treatment of obliterated root canals. J Endod. 1988;14(11)565-‐567.
42. daCunho FM, Desouza IM, Monnerat J. Pulp canal obliteration subsequent to trauma: perforation management with M.T.A. followed by canal localization and obturation. Brazilian J Dent Traumatol. 2009;1(2):64-‐68.
43. Haywood VB. Tooth Whitening: Indications and Outcomes of Nightguard Vital Bleaching. Hanover Park, ill: Quintessence; 2007
44. Haywood VB. The “bottom line” on bleaching 2008. Inside Dentistry. 2008;4(2):82-‐89.
45. Haywood VB. History, safety, and effectiveness of current bleaching techniques and applications of the nightguard vital bleaching technique. Quintessence Int. 1992;23:471-‐488.
46. Haywood VB. Orthodontic caries control and bleaching. Inside Dentistry. 2010;6(4):36-‐50.