77236914 Study Guide Treatment of Edentulous Patients

7/25/2019 77236914 Study Guide Treatment of Edentulous Patients

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STUDY GUIDE Prosthodontic Treatment of the Edentulous Patient

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Table of ContentsINTRODUCTION Overview Attendance Student Performance & Evaluation Lab Attire LabManual and Assigned Texts Criteria Sheets Due Dates Faculty Critique Lab Supplies

STUDY GUIDE for Boucher's Prosthodontic Treatment of the Edentulous Patient

Chapters1. EVALUATION OF THE PATIENT Diagnosis and Prognosis for Complete Dentures 2. LIMITATION OF COMPLETE DENTURES Nature of the Denture Foundation Complications in Wearing Completcient use of Complete Dentures Problems of the Adjustment Period The Need for Tissue Recovery Periods Cleaning and Storing Dentures Importance of Recall Necessity of a Good Diet Propaganda and Its Sources When and How Patient Education Should Be Presented Present Status of Patient Education

3. PRELIMINARY IMPRESSIONS AND STUDY CASTS4. ANATOMY OF THE EDENTULOUS PATIENT Maxillary Mandibular 5. FINAL IMPRESSIONS -NOTES

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General Discussion Anatomic Considerations in Complete Denture Extension

6. CUSTOM TRAYS, BORDER MOLDING, AND FINAL IMPRESSIONS Custom Trays Border Molding and Final Impressions 7. CONSTRUCTION OF A STABLE RECORD BASE AND WAX OCCLUSAL RIMS 8. MAXILLO - MANDIBULAR RELATIONSHIPS Posterior Palatal Seal / Post Dam Face Bow Transfer - Mounting the Maxillary Cat Centric Relation Record - Mounting the Mandibular Cast Clinical Adjustment ofContour Rims & Tentative Registration of Maxillo-Mandibular Relations

9. ARTIFICIAL TEETH & 0 DEGREE SET-UP General Discussion Denture Teeth - Acrylic vs. Porcelain Set-Up of 0 Degree Teeth

10. TRY-IN AND COMPLETION Try-In Speech Sounds and Anterior Tooth Position Complete Denture Wax-Uw Preservation Processing and Finishing Dentures Insertion and Occlusal Evaluation Denture Care Instructions Post-Insertion Treatment

11. SET-UP OF 30 DEGREE DENTURE TEETH 12. ADDITIONAL DENTURE SERVICES Immediate Dentures Repairing Fractured Dentures Replacing Teeth Denture RelinDenture Rebasing

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EVALUATION OF THE PATIENTChapter 1

EVALUATION OF THE PATIENT: DIAGNOSIS AND PROGNOSIS FOR COMPLETE DENTURES In theconstruction of complete dentures, success or failure may depend upon a clear understanding of the limits and possibilities of each case. To obtain this, a thorough, systematic examination of all the conditions of the mouth and of the patient is essential. The following outline will aid in completing the Complete Denture Record Chart and in evaluating the patient. 1. AGE Record chronological age whenever possible. When the exact information is unobtainable, an estimate may bemade and age listed as "under 40", "40 to 60 years", and "over 60 years". The significance of the age from the prosthodontistc standpoint is in the ability of apatient to wear dentures successfully. Two main factors present themselves: A.Adaptability It is generally believed that young people adapt themselves with greater ease and therefore are more likely to have successful denture experiences.Preservation of tissues is of vast importance as well. Mental attitudes of thepatient must also be considered and discussed with the students. B. Physiological Condition of Supporting Structures Age is a factor in the condition of the supporting structures. From the biological standpoint, it would be difficult to name the period in a patient's life when the ridges are least subject to change. There probably is never a static period. Normally, the rate of change in the edentulous alveolar ridge is comparatively slow. Generally, however, metabolism or therate of interchange of nutritious elements for bone formation is better in youngpeople. Under normal conditions, the process of aging (from the prosthetic stan

dpoint) would imply poorer calcification of bones. The role of the endocrine glands in this connection is now better understood, especially the influence of thesex glands on calcium metabolism. In older people, when sex hormones are at a minimum or entirely absent, the quality of the bone is poor and more unfavorableexperiences in wearing dentures may be anticipated. The overlying mucosa is affected in a manner similar to the bone. 4


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2. SEX Record the sex of the patient. Sex has a bearing on denture constructionfrom the standpoint of esthetics and of the influence of sex hormones on the supporting structures. In the first category, women can be more demanding and are usually more concerned with their appearance than men. Unlike men, women may regard appearance even above the efficient functioning of the replacement teeth. Inthe second consideration, normal physiologic change decrees that women undergo menopause, a period productive of many problems which mitigate against easy denture construction. The withdrawal of some or most of the ovarian secretion affectsthe alveolar ridge adversely, both as to the bone and the overlying gingivae. Often, mental instability of varying degrees accompanies the menopause and this factor may make difficult the wearing of dentures oven to a greater degree than do the physical changes. 3. OCCUPATION The occupation of an individual may demandspecial consideration in denture construction from the standpoint of esthetics,phonetics, or function. People generally making public appearances, such as artists, actors, salesmen, public speakers, singers, teachers, etc., are particularly concerned with the esthetics and phonetics of replacements while tradesmen, mechanics, or laborers, etc., are concerned with functional efficiency. Occupation is also important because of possible deleterious effects on health as in occupational metal poisonings, or bronchial irritations. People like beauticians, who open bites bobby pins with their teeth, might place leverage on the front of the CD and cause problems of function; i.e. retention. 4. GENERAL HEALTH Record on chart as normal or indicate pertinent illnesses. The general health of an individual has a bearing on success in denture construction. This is especially so since so many of these patients are at an age that general health deficiencies of

varying degrees expected. Healthy patients can make a better adjustment than the ill, tense, nervous patient. Many chronic, debilitating diseases offer a poorprognosis. Many diseases have early oral manifestations. Some diseases affect the jaws more directly than others and may give rise to symptoms which, if recognized, may save the operator considerable annoyance and enable him to serve the patient better. The symptoms may be subjective, as pain or burning sensations; orthey may be objective, actually involving tissue change in both bone and overlying integument. Some of the diseases causing pain or burning sensations may be anemia, diabetes, aclorhydria, estrogen privia or other endocrine or nutritional disorders.

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Prominent here also are psychological disturbances resulting from financial troubles, family worries, or maladjusted sex relations. Diseases causing actual tissue changes are syphilis, tuberculous, blood dyscrasias, diabetes, endocrinopathies such as acromegly, neoplasms or osteodystrophies of undetermined origin. Caution should be exercised in the care necessary in denture construction followingradiation therapy in the region of the jaws because of the detrimental effect onthe ability of tissues to repair and because of the susceptibility of infectionfollowing injury. Other types of diseases affecting success in wearing denturesare those relating to the bronchi, as in asthma. Metal poisonings are very seldom encountered in edentulous cases; bismuth or phosphorous might be considered occupational but more properly would belong under the pathological as they are not induced by occupation. For example, bismuth poisoning may not be an occupational disease solely, as this metal is used to a considerable extent in the treatment of syphilis and some nervous disorders. The following is a list of some of the diseases frequently encountered in a prosthodontic practice and the considerations that must be made by the dentist: DIABETES How is the problem met by the prostbodontist? a. The patient must have this condition under proper medical control. This is important, for the success of dentures goes hand in hand with medical control. b. The operator should use an impression technique that will producemaximum physiologic compatibility of the denture base with the supporting tissues c. Careful occlusal corrections should be accomplished to remove all interferences. d. The food table should be small and the patient should be given detailedinstructions on eating habits and oral hygiene. e. Frequent evaluation of the dentures is necessary. ARTHRITIS The problems for the prosthodontist are as follo

ws: a. The limited movement of the mandible during impression making may necessitate special trays and procedures.

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b. It may be difficult to get proper registrations. Generally, the tactile method is the most satisfactory. c. Occlusal corrections must be made often because of arthritic changes in the tempromandibular joint. BELL

S PALSY In the fabrication of complete dentures, the following problems are presented: a. Retention is often hard to achieve, and an adhesive may be necessary. b. Support becomes a problem. Both function and esthetics emphasize the importance of support for paralyzed musculature. Such support can be accomplished by using resins, modeling compound or wax extensions. c. The patient should be educated in mastication and oral hygiene. PARKINSON'S DISEASE a. Control of the patient during fabrication of thedenture can be accomplished with sedatives. b. Retention is difficult, and an adhesive may be necessary. c. It may be wise to remove dentures when they are notin use. This will add to the comfort of the patient and eliminate the danger ofswallowing them. ANEMIA It is important that patients with anemia first be placed under proper medical care. Next, the dentist must achieve: a. Efficient dentures, since diet is such an important part of the medical treatment. b. A small food table with maximum supporting area to keep the supporting tissue from beingoverstimulated. c. Careful patient instruction for good oral hygiene. RADIATIONRadiation is such an extremely complex subject that hours could be spent discussing it alone. Though I can do no more than mention it, the following should be remembered.-

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a. If dentures are to be made, it in imperative that no abrasion or irritation be present on the supporting tissues. b. An open lesion may be the start of a serious condition, namely osteonecrosis. c. It is best not to use dentures at all over irradiated tissues, but if dentures are necessary, they should not be used until at least two years after radiotherapy. NICOTINIC STOMATITIS Nicotinic Stomatitis is a form of chemical injury to the oral mucosa and mucous glands. a. Thearea may be covered with a denture.

b. Even in patients with natural dentition, the area is covered as part of the treatment. c. Because of excessive secretion from the mucous glands, plaster is the impression material of choice. CLEIDOCRANIAL DYSOSTOSIS a. The prosthetic treatment calls for fabrication of the dentures over the unerupted teeth.

b. Teeth should be removed at they erupt, for very little bone structure would be left if the supernumerary, impacted and unerupted teeth were all extracted atonce. OSTEITIS Osteitis Deformans in a chronic osseous disturbance. The prosthetic situation is this: The continual enlarging and changing of supporting structures, especially of the maxillary tuberosities, necessitate frequent remakes andadjustments. AGROMEGLIA The prosthetic requirement is simply this:

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Make a periodic check of the prosthesis to determine whether the continuing growth of the mandible and maxilla necessitates any adjustment or reconstruction. LEUKOPLAKIA Leukoplakia is a term often loosely applied to smooth white, diffuse patches on the mucous membranes of lips, tongue, and cheeks. a. Biopsy is the method of diagnosis; if the histologic examination indicates a premalignant lesion,the affected area should be removed. If reports state that the patch on the membrane is heaped-up keratin, surgical intervention is unnecessary.

b. It may be covered with a denture. 5. DENTURE HISTORY - DENTURE WEARING EXPERIENCE The length of time and the fact that patients have worn dentures have a bearing on the type of foundation present, muscle tone and development, functionalability, mental reaction and cooperation and the correctness and ease of establishing vertical and maxillo-mandibular relations. The type of denture, whether full or partial, metal or plastic, may have either a beneficial or detrimental effect on the end results obtained. The ease with which patients can establish newhabits is important. A patient who has successfully worn dentures before might be easier to work with than one who has had several unattractive and/or inefficient dentures. Important is the patient with a bag full of dentures. They usuallypresent a bleak outlook. How could so many dentists all be wrong? Yet a favorable denture history offers a good prognosis. Register the complaints and problemsof previous dentures. Examine old dentures and evaluate them for retention, stability, occlusion, extension, etc. If old dentures were completely satisfactory,use these as models. 6. MUSCULAR TONE Usually normal when no degenerative changes have occurred in the muscles of expression and mastication,

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Chapter 2 LIMITATION OF COMPLETE DENTURESSome patient have mistakenly believe that complete dentures mean the end to oralproblems and that the original dentures should last forever. Nothing is furtherfrom the truth and expectations of this nature must be corrected. The relining,remaking, or occlusal correction of complete dentures is necessary whenever tissue changes that promote instability of the denture have occurred. Patients mustbe made fully aware of the necessity for such procedures. Artificial substitutes are rarely as satisfactory from a standpoint of comfort and efficiency as theonce healthy structures which they replace, but in most instances appearance andspeech need not be compromised in the complete denture service. NATURE OF THE DENTURE FOUNDATION The phenomenon of bone resorption due to excessive pressure ofdentures and the resultant change in the denture foundation should be explainedto the patient. Some degree of change will usually occur under the most ideal conditions. Excessive amounts of soft tissues interposed between the denture andthe supporting bone will render the denture less stable. An unstable denture seems to exert pressures beyond the physiological tolerance of the tissue. Often observed is a vicious circle of excessive movement, traumatic pressure, resorption, and an increased amount of soft tissue. Therefore, an adequate diet and good nutrition are essential to help maintain a relatively healthy condition of the supporting structures of the dentures. Prolonged illness may also favor a faster resorption of bone than would be encountered during health. COMPLICATIONS IN WEARING COMPLETE DENTURES Certain undesirable situation of a physical, emotional oroccupational nature will be evident during the diagnostic phase of the completedenture service. Patients having complications of this nature include: (a) those

for whom oral surgery would enhance the denture foundation but is contraindicated for various reasons; (b) those who cannot control jaw or tongue movements, (c) those who have experienced excessive vertical and horizontal resorption of theresidual ridges, (d) patients who have had maxillofacial surgery,

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(e) patients who demand more than can possibly be accomplished, considering their condition, (f) patients who seemingly cannot adjust psychologically to complete dentures, (g) patients who lack mental capacity to comprehend fully the complete denture service, and (h) patients who play wind instruments. Persons who fallinto thes e categories should be informed of the limitations, imposed by theirparticular situation, on the wearing of dentures. EFFICIENT USE OF COMPLETE DENTURES Efficient use of complete dentures is a learned process. Training in the use of complete dentures is primarily directed to mastication and speech, but initially involves overcoming a feeling of strangeness when the dentures are in themouth. At first, most patients experience a sensation of fullness--the tongue feels crowded by the lower denture and the upper lip feels distended. This feelingusually passes within a few days, and it is interesting to note that eventuallymany patients feel as strange without their dentures as they did when the dentures were initially placed. Stable dentures enhance mastication and speech. The tongue can be an important factor in stabilizing complete dentures, particularlythe lower denture. The patient must learn to hold his tongue in a position on top of the lingual flanges of the lower denture and completely fill the tongue space of the lower denture. In this normal position only the occlusal surfaces of the lower teeth are visible. A retracted tongue has a tendency to physically dislodge the dentures and, at the same time, positions the floor to the mouth, thusbreaking the border seal of the denture. The retracted tongue position can be corrected through exercises and concentrated effort by the patient. Learning to eat with dentures takes time and perseverance. The patient should be advised to avoid foods that are sticky, tough, and generally difficult to prepare for swallow

ing. The chewing of softer foods should be mastered before resistant types of food are eaten. Unilateral chewing with complete dentures should be discouraged; chewing on both sides simultaneously will stabilize the dentures. The trick seemsto be to cut the food into small pieces and to divide the bolus of food in themouth and position it on both sides of the lower denture with tongue. Complete denture patients should deny themselves the natural habit of biting with the front teeth. In the denture, the relationship of the anterior teeth to the residualridge is conducive to increased tipping forces when pressure is applied to the incisal edges. The crests of the residual ridges in the anterior portion of the mouth are least suited to withstand pressure from biting, and bone seemingly resorb quite rapidly from trauma in

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these regions. Patients who had no particular desire for apples and corn on thecob when they had natural teeth seem to develop a craving for these foods when they have complete dentures. At times, food served at social gatherings demands that the denture-wearer commit acts of eating that are especially detrimental toresidual ridges. For example, celery and carrot sticks require biting rather than cutting with a knife. If such food is eaten, biting in the canine region is preferable to biting with the anterior teeth. Pressure to the upper denture, created by biting, is better tolerated when directed inward and upward. Relative values must be placed on the situation occurring at the moment, for sometimes the cure is worse than disease (embarrassment vs. biting). Correctly-made complete dentures seldom interfere with speech and often improve speech. Difficulty with certain words may occur during the "getting acquainted" period, but this is usuallyshortly resolved by practice. Difficult words should be repeated out loud untila speech defect no longer exists. On occasion, the position of the anterior teeth, the premolars, the molars, or the shape of the palatal surface will have tobe altered to clear up a speech difficulty. PROBLEMS OF THE ADJUSTMENT PERIOD Patients with new dentures usually suffer from discomfort due to soreness occurring within a few hours after the dentures have been initially placed in the mouth.Because of soreness, more than one adjustment of the dentures may be required within the first two weeks of use. The patients will accept the discomfort and the adjustment if he is forewarned; otherwise, he may question the quality of thedenture service. Under no circumstances should patients attempt to adjust the dentures themselves. THE NEED FOR TISSUE RECOVERY PERIODS Complete dentures shouldbe removed from the mouth for a minimum of six to eight hours a day to allow th

e supporting tissues to rest. Most patients find the most convenient time to doso is during the night. If sleeping without the dentures causes either temporomandibular joint disturbances or muscular disturbances, provisions should be madefor several short periods of tissue recovery during the day. Oral structures that are called upon to bear an imposed load seemingly greater than that encountered with healthy natural teeth will react more favorably to additional pressures if the forces are not constantly applied. Should the removal of the complete denture produce a mental reaction of insurmountable embarrassment, the overall benefit to the patient

s well-being should be realized by allowing the restoration toremain in the mouth except for short rest periods during privacy.

CLEANING AND STORING THE DENTURES Residual foods should be removed from the denture after each meal and the mouth should be thoroughly rinsed. Such a procedure

will help eliminate "denture breath" caused by

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decomposing foodstuffs and stagnant saliva. Food retained between the denture base and the oral tissues does not contribute to stability of the denture and mayresult in an inflammatory condition of the basal seat tissues. The dentures should be held carefully when being cleaned. A basin partially filled with water will provide a cushion if the dentures are dropped during the cleaning process. Thelower denture should be held on one side only to avoid a midline fracture due to squeezing the denture. Dentures made of acrylic resin should be placed in water or a denture cleaning solution when not in the mouth since acrylic resin dentures have a slight tendency to slight dimensional changes when allowed to dry. Covered plastic containers especially designed to store dentures are available commercially, and dentures should be safely stored in them during periods of tissuerecovery, out to the reach of curious or inquisitive persons. IMPORTANCE OF RECALL A periodic recall should be suggested, and its objective should be explainedto the patient. The elapsed time for recall will depend on the physical, mental, and emotional situations encountered during the course of treatment. Recalls spaced four or five months apart are not unusual. However, the patient should beexamined at least once a year. Early interception of a developing undesirable situation can improve the oral health of the patient as well as save him money. For example, early detection of a discrepancy between centric relation and centricocclusion may be corrected before gross changes to the supporting structures take place. NECESSITY OF A GOOD DIET It is the responsibility of the dentist to inform the patient of evidence of inadequate diet and to suggest a consultation with a physician to correct diet deficiencies or sequelae of an insufficient diet.The dentist is obligated to have the patient

s dietary deficiencies corrected b

efore proceeding with total definitive treatment. Cooperation between the patient, the dentally oriented physician and the dentist will result in a greater service to the patient than would otherwise be possible. It is important that dietary habits be evaluated at each recall appointment. Literature on the preparationof foods to render them suitable for mastication by patients with complete dentures should be supplied by the dentist. PROPAGANDA AND ITS SOURCES Some commercial firms employ the media of television, radio, and newspapers and other periodicals to advertise services or products for patients who have complete dentures. For the most part, this bombardment of advertising is directed toward correctingthe ills of faulty dentures. The advertising is legal but is an injustice to many denture wearers, since

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it not only suggests usually unobtainable results but also delays many patientsfrom seeking the advice of a dentist. Another source of misinformation to the patient with complete dentures is a fellow denture wearer. The experiences of onepatient are relayed to another patient and are represented as the gospel. But each patient has individual problems and what applies to one will not necessarilyapply to another. Patients should be warned about miracle fix-its and should seek advice about dentures only from a dentist. WHEN AND HOW PATIENT EDUCATION SHOULD BE PRESENTED Education of the patient begins at the initial contact with thedentist. Patients are very sensitive to their reception, the demeanor of the dentist, and the atmosphere of the dental office. Education of the patient should continue throughout the complete denture service, but is of primary importance atthe presentation of the treatment plan. Patients have a right to know the whats, whys and hows of that which is being performed on and for them. Questions should be answered logically and patiently; explanations or demonstrations which will be informative to the patient should be given. Predicted problems and limitations of his complete denture service are usually well- accepted by the patient; unanticipated problems,. arising after the initial placement of the dentures, arenot as readily excused by the patient. An enthusiastic approach to patient education on the part of the dentist will be reflected in the patient

s acceptance of the treatment plan, problems., and limitations. The progress of the complete denture service is of vital importance to the patient, and often his acceptance is heightened by visual aids that help him understand his own oral problems. Thepatient should not be expected to retain all the information presented to him prior to the completion and insertion of the restorations. For this reason, one of

the current booklets containing the salient points of complete denture treatment and care should be given the patient for review. PRESENT STATUS OF PATIENT EDUCATION Currently, the education of patients is probably one of the most neglected phases of the complete denture service. Many dentists are not motivated to provide adequate information about complete dentures; therefore, they do not take the time to give this important service. The lack of motivation may be the resultof weariness on the part of the dentist - his repeated educational efforts having constantly fallen on the ears of his indifferent patients - or it may be theresult of inadequate instruction concerning the importance of patient education.However, a dentist has a moral as well as a professional obligation to presentto the patient any information which may be useful in solving the oral problemsfor which the patient initially sought help.

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Chapter 3

PRELIMINARY IMPRESSIONSA. DEFINITIONA negative imprint of an edentulous arch.

B. PURPOSETo make a negative imprint of an edentulous dental arch from which a positive cast can be poured.

C. OBJECTIVES1. Perform and discuss tray selection for preliminary impressions for CDs. 2. List types of materials for preliminary impressions for CDs. 3. Be familiar with the advantages and disadvantages of each impression material. 4. Be familiar withthe properties and characteristics of alginate impression material. 5. Performan impression procedure using alginate. 6. List the requirements of a good impression. 7. Be familiar with the properties of dental stone. 8. Perform and discuss the beading and boxing of an alginate impression. 9. Be familiar with alternate methods for #8 above. 10. Perform and describe the mixing, pouring and trimming of a preliminary study cast. 11. Discuss the requirements of a good preliminary/study cast.

D. INSTRUMENTS AND MATERIALS1. Assortment of sterilized perforated edentulous impression trays 2. Knife 3. A

lginate 4. Mixing bowl and spatula 5. Water measurer 6. Periphery wax 7. Boxingwax

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height of the border. Keep the blade in constant contact with the tray border. Pull the blade downward with one hand as the tray is rotated in the other hand. Wipe along the inside of the tray between borderge crest bilaterally. For maxillary spread the material across the palate. These movements serve to spread the material evenly in the tray, to eliminate bubbles and remove any excess material.At this point additional material may be added if necessary.

Making the ImpressionMaxillary: While holding the upper lip forward, position the loaded tray slightly anterior to its final position and carry the tray upward and slightly posteriorly until the alginate just fills the mucolabial-muconuccal fold. The fully seated tray should be positioned to that 1) the handle is approximately parallel tothe ala-tragus line antero-posteriorly; 2) parallel to a line through the pupilsof the eyes from an anterior aspect; and 3) centered over the arch. The impression can be removed by grasping the tray with the thumb and first two fingers ofthe hand and by inserting the index finger of the other hand between the patient

s cheek and posterior flange of the impression. This will break the seal and permit it to be removed. Rinse the impression with cold water, shake off excess water and examine for details. Study the entire impression to make certain of thefollowing: 1) that the basal seat area is included; 2) that the entire mucobuccal-mucolabial fold is filled; 3) that the buccal and labial frena are indicated;4) that the pterygomaxillary notches and fovea palatinae are indicated; and 5) that the tissue surface of the impression present a smooth, non-grainy, non-folded surface. Mandibular: While holding the lower lip forward, position the loaded

tray over the mandibular ridge. During the seating of the tray, direct the patient to raise the tongue above the tray in order to prevent impingement of the tongue and tissues of the floor of the mouth. Carry the tray to place in a downwarddirection to complete its placement and simultaneously direct the patient to relax the tongue. The fully seated tray is positioned so that 1) its handle is approximately parallel to the inferior border of the body of the mandible antero-posteriorly; 2) parallel to a line through the pupils of the eyes from an anterioraspect; and 3) in the center of the face from a superior aspect. Remove the impression in a manner similar to that described for the maxillary impression. Rinse the impression with cold water, shake and examine for details. Make certain ofthe following: 1) that the entire basal seat area is included; 2) that the frena attachments are all indicated; 3) that the external oblique and mylohyoid ridges are indicated; 4) that the retro-molar areas are included; and 5) that the su

rface of the alginate is smooth, non-grainy and without folds. Dentiform: Centerthe loaded tray over the dentiform and seat with a gentle rocking motion untilexcess alginate appears at all of the borders. Prior to final set, excess material along the base of the dentiform can be removed with the edge of the spatula.If the material has set, excess can be removed with a sharp knife. When the material is set, grasp the tray handle and the base of the dentiform and slowly pullapart. In some instances a gentle pry with a knife may be required. Examine impression for accuracy of

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anatomy, lack of voids and bubbles, proper seating of tray and lack of pressurespots. The impression should also be smooth, non-grainy and without folds. If large voids or pressure spots appear, or, if the tray has been improperly seated,remove impression material and DO IT OVER!

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F. PROBLEMS AND ERRORS1. Selecting an impression tray to small will result in incomplete coverage of the basal seat area and a penetration of the flanges of the tray through the alginate. 2. Selecting an impression tray to large results in a distortion of the border tissues and an incomplete compression of the alginate over the ridge areas.3. Improper mixing of the alginate will result in an inaccurate impression and/or the lack of detail on its surface. 4. Improper loading and distribution of the alginate in the tray will cause an over distortion of the border tissues in some areas and an incomplete impression in others. 5. Failure to center the tray properly results in metal flanges of the tray making contact or cutting the ridgetissues. The alginate is then prevented from filling in the mucobuccal fold onthe tight side and an over distribution of the cheek on the opposite side. 6. Improper removal of the tray, such as removing before rigidity has been achieved,will result in a distortion. Distortion may also occur as a result of careless handling before pouring the cast, such as storing the impression for too long.

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BEADING, BOXING & POURING STUDY CASTSA. MATERIALS1. Beading or periphery wax 2. Boxing wax 3. Wax spatula 4. Mixing bowl 5. Plaster spatula 6. Glass slab 7. Knife

B. DIRECTIONS BEADINGIt is usually very difficult to apply beading or periphery wax to an alginate impression that is made in the clinic in a real patients mouth. However, wax can be applied to a clinical impression or to the impression made of the dentiform ifthe alginate is trimmed back properly. Excess alginate should be trimmed back to, and just short of the periphery roll. That is - the mucobuccal fold should bepreserved and the tray exposed (refer to diagrams at the end of this chapter).Place 2 strips of beading wax or 1 strip of periphery wax around the entire edgeof the impression, about 2-3 mm below the height of the peripheral roll. Be certain that, when viewed occlusally, the beading wax can be seen around the entireimpression. The mandibular impression must also be filled with a sheet of wax (use boxing wax here) in the lingual/tongue area. The beading creates the "land"of the cast and preserves the outer portion of the mucobuccal fold or border area. *NOTE: All mandibular casts for Prosthodontics have a full base. Except for certain procedures in Fixed Prosthodontics, NEVER MAKE A HORSESHOE SHAPED LOWER.

BOXINGUse a strip of boxing wax long enough to surround the impression with about an inch overlap. Place the boxing wax strip about the beading wax with its flat surf

ace perpendicular to the beading wax. *NOTE: Once the boxing is completed, be certain that when viewed from above, the beading wax can be seen COMPLETELY aroundthe impression especially at the mandibular retro-molar pad areas - otherwise there will be little if any land in those areas of the poured cast.

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POURINGFollow the manufacturer's directions and prepare a proper amount of artificial stone in a plaster bowl. A denser mix, free of air bubbles, may be achieved by useof a Vacuspat mechanical spatulator. Use the Vacuspat if it is available. Turn on the vibrator and hold the boxed impression in one hand with one corner slightly higher than the rest of the impression. Flow the stone into one posterior corner of the impression from the tip of the spatula, allowing the stone to flow slowly over the interior of the impression guarding against the entrapment of air bubbles. **The entire interior of the impression should be filled in this manneruntil the stone reaches the top of the boxing wax.

ALTERNATE POURING METHOD - INVERTING (see diagram)Follow the above directions down to **... The interior of the impression shouldbe filled in this manner until the stone reaches slightly above the mucobuccal fold of the impression. Without use of a vibrator, place the remainder of the stone on the piece of tile or the glass slab in the form of a mound. Invert the previously poured impression in this mass and depress it to develop a cast thickness of 3/8 inch at the thinnest portion and allow the stone to exceed beyond the fold slightly.

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RECOVER CASTSAllow stone to set for 40 to 45 minutes. Remove boxing and beading wax. If stonehas pushed up and onto the tray use a knife to remove this thin "flash" beforetrying to recover the cast. Use the knife to gently separate the impression fromthe cast. Using a model trimmer, trim both casts to approximately the size of the patient's dentiform. You should keep this size in mind for trimming clinical casts. REMEMBER - the base of the cast shoul d be 3/8ths to 1/2 inch thick and theland area should be 4mm wide!

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Chapter 4 ANATOMY OF THE EDENTULOUS PATIENT A. OBJECTIVES1. Identify, locate and discuss the importance and/or action of macroscopic supporting and limiting structures in the fabrication of a complete denture. 2. List, describe and discuss primary and secondary denture stress bearing areas 3. Describe and discuss relief and retentive areas 4. Be familiar with microscopic anatomy 5. Discuss clinical considerations of microscopic anatomy 6. Discuss non-surgical methods of patient preparation for CD

s 7. Discuss surgical methods of patient preparation for CD

s

MAXILLARY COMPLETE DENTURE BORDERSThe following is a list of the significance and movements or manipulations the dentist and/or the patient make to capture the following important denture borderlandmarks: 1. Labial Frenum Usually no muscular fibers in the edentulous state.Must be manipulated by the operator in order to get a more defined recording. 2. Orbicularis Oris Exaggerated "M" sound. 3. Buccal Frenum Buccinator "O" or "E"sound or in patients inability to Muscle/Buccinator Insertion manipulate by pulling corner of mouth out and down. 4. Coronoid Process Lateral border of post malar pocket. Open moderately wide and move mandible side to side. 5. Palatoglossus Posterior border of post malar pocket. Open wide and place tongue out of the mouth.

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6. Hamular Notch DOES NOT interfere with pterygomandibular raphe (from hamulus to retromolar pad) between tuberosity and hamulus of medial pterygoid plate posterior boundary. Open and close several times. 7. Pterygomandibular Ligament/RapheIs pulled forward when mouth is open wide 8. Fovea Palatini Remnants of nasopharyngeal ducts (coalescence of mucous glands). Always on soft tissues. 9. Post Dam Area Comprised of tensor palatini; predominantly horizontal fibers Levator veil palatini; predominantly oblique fibers. Uvealis; predominantly vertical fibers. 10. Vibrating Line Imaginary line - notch to notch, usually about 2mm in frontof fovea. Always on soft tissue. Higher vault - more abrupt and forward. Flat vault - more posterior. Denture ends at/or 1-2mm past this line.

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MANDIBULAR COMPLETE DENTURE BORDERSWhen teeth are lost the mandible gets shorter and narrower bucco-lingually. Thecrest gets narrow and sharp. The width of bone widens in molar areas as crest resorbs. In the anterior, bone is lost from the lingual and bone appears to move forward. Bone is often at the level of floor of mouth when mandible is viewed from side. Overall, mandibular ridge is high in posterior and low in the anterior.The following is a list of the significance of, and movements or manipulations the dentist and/or the patient make to capture the following important denture border landmarks:

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1. Labial Frenum No muscular fiber. Should manipulate. 2. Orbicularis Oris Exaggerated "M" sound. 3. Anterior Masseter Fibers pass outside buccinator. Muscle pushes in. Clenching or biting closing force while bordermolding will contract muscle. 4. Pterygomandibular Ligament Open wide. Stretch. 5. Retromylohyoid Posterior Border Styloglossus, Stylohyoid, Palatalglossus; Place tongue over handle oftray. 6. Mylohyoid Fibers become shorter or smaller progressing anteriorly. Place tongue into opposite cheek. 7. Genioglossus Place tongue over handles of trayand wet upper lip. 8. Anterior Portion Several muscles attached (buccal frenum to buccal frenum). Short flange (mental foramen - often on top of ridge). Labialfrenum attached to orbicularis oris sensitive and active. 9. Buccal Vestibule Extends from buccal frenum to retromolar pad and from crest of ridge to cheek. 10.Buccal Frenum "OU" or "E" sound if necessary. Connects with band from maxillarythru modiolus. Fibers will pull and must be free to move. Lip must be supported. 11. Buccinator Muscle "OU" or "E" sound if necessary. Extends from modiolus topterygomandibular raphe. 12. Buccal Shelf Bordered: medially by crest of ridge,anteriorly by buccal frenum, laterally by external oblique ridge and distally by retromolar pad. Buccinator fibers run anterior-posterior and parallel to the bone. Inferior portion attached to buccal shelf. WILL NOT LIFT DENTURE 1 stress bearing area of mandibular denture. Has good cortical bone at right angle to occlusal plane.

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13. Buccal flange Extends from frenum to anterior masseter. Is wide and extendsinto the cheek to cover buccal shelf. 14. External Oblique Ridge DOES NOT LIMITextent of buccal flanges. Flange can extend up to or over ridge wherever the muccobuccal fold ends. Use the external ridge AS LANDMARK -- TEST FOLDS IN THIS AREA WITH MIRROR. 15. Distobuccal Flange Masseter region - flange converges medially with action of masseter. 16. Distal Extent Limited by buccinator and lateral bony process. Denture extends to include retromolar pad which provides a soft tissue seal. 17. Retromolar Pad Contains some glandular tissue, tendon of temporalmuscle, buccinator fibers, fibers of the superior pharyngeal constrictor on thelingual and from the pterygomanidular raphe at the distal.

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CHAPTER 5 FINAL IMPRESSIONS - NOTES A. DEFINITIONAn impression is a record of the negative form of the tissues of the oral cavitythat make up the basal seat of the denture. It is used to make a CAST - a positive replica. Maximum support is provided by thick fibrous connective tissue thatis attached firmly to compact bone. The mid-palatal suture, for example, has non-resilient mucous membrane that does not tolerate much. Therefore, impressionsmust selectively place pressure on mucous membrane and bone in amounts compatible with their histological tolerances.

B. CHARACTERISTICS OF A GOOD IMPRESSION1. Include everything within limits of health and function 2. Borders should bein harmony with limiting structures 3. Physiologic type bordermolding 4. Properspace allowed for impression material 5. Selective pressure while making impression 6. Should not damage tissue 7. Should be properly positioned 8. Dimensionally stable materials 9. Shape of impression is similar to form of denture

C. 5 OBJECTIVES OF IMPRESSION to provide:1. Retention 2. Stability 3. Support 4. Esthetics 5. Maintain Health 1. Retention - Resistance to removal in direction opposite that of insertion. Resists gravity, sticky foods, opening and closing jaws. It is the means by which dentures are held in mouth. If tissues are displaced under pressure the denture may lose retention because of change in adaptation of basal surface. 2. Stability - Qualityof denture to be firm, steady and constant in position when forces are appliedto it. It especially provides resistance against horizontal rotating movement. I

t depends on the size and form of basal seat, quality of final impression, formof polished surfaces and location and arrangement of artificial teeth. 3. Support - Resistance to vertical components of mastication and occlusal direction towards the basal seat 31


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4. Esthetics 5. Maintain Health

D. THE IMPRESSION ITSELF1. Consistency - can control the position and shape of the oral tissues. Soft orfluid impression materials displace tissues less. Stiffer impression materialswill displace tissue. 2. Tray of Correct Size a. should not displace tissues b.design of tray should be related to type of impression material selected, e.g.,-compound needs lot of room - ZOE (like toothpaste is thin and requires very little room - plaster of Paris is in between 3. ZOE, plaster, irreversible hydrocolloid, silicone, polysulfide, polyether, tissue conditioning materials all have been used for secondary (final) impression a. Plaster usually sets slow, requiresa separating medium before pouring, and absorbs mucous secretions. b. ZOE requires a tray of almost exact dimensions. It is so thin that mucous secretions cause defects in surface of impression. c. Hydrocolloid capture mucous bubbles, losemoisture, and distorts easily. It should be poured immediately and the weight of stone may distort it. d. Tissue Conditioning Materials are very good, accurateand good for functional impressions because it flows up to 24 hours. e. RubberBase (polysulfide rubber). Tray must fit accurately so that rubber can be closely confined to tissues to be accurate. Very good for thin mandibular ridges withsoft tissue undercuts. Can also be removed (separated) from cast without breaking cast. f. Polyether is good. It can be shaped with fingers and can support itself 4-5 mm. Its disadvantage is that it is opaque -- CANNOT SEE PRESSURE SPOTS inthe impression.

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E. TECHNIQUE1. First you have to BORDERMOLD the final impression tray. Border mold by movingtissues against soft material that is SUPPORTED and controlled by tray. Bordersof tray must be 2 mm short of reflection of tissue. The tray should always be checked in the mouth before border molding is started as the preliminary cast mayhave been more than 2 mm over extended. Green stick is added in sections, heated in a flame, tempered in a water bath, and placed in mouth. 2. Border molding will be affected by: a. viscosity of material (soft or stiff) b. space availablefor material c. type and amount of manipulation d. quality of tissue - loose ortight 1. Maxillary border molding - upper lip out, down and in - buccal frenum -cheek out, down, in, back and forward - post buccal - cheek out, down, in, movejaw side to side for coronoid process - post palatal area - compound is put onthe tray over the vibrating line area and thru hamular notches. Place in mouth -relax, swallow, relax, open wide - border molding of post palatal seal will i.slightly displace soft tissue to enhance seal ii. guide for positioning tray forimpression iii. prevent excess from running down throat 2. Mandibular border molding - anterior labial - lip out, up, in - buccal frenum - cheek out, up, in, back, forward - buccal shelf - cheek out, up, in - mandibular lingual flange - 5steps i. anterior region - look for clearance of lingual frenum, sublingual folds, submaxillary ducts ii. add compound to anterior lingual flange. Have patientstick out tongue and then push tongue against the palate to get functional border. iii. premylohoid fossa area (canine - premolar area) - flange will extend below mylohyoid line in this area and will slope towards tongue.

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iv. add to molar regions between pre and post mylohyoid areas, protrude tongue,allow action of mylohyoid muscle to shape the flange in this area. NOTE: After you are finished - relieve compound to prevent the tray from binding in this area. The area will be recaptured by the impression material. v. very back of lingual flange - add compound and protrude tongue so that the retromylohyoid curtain and superior constrictor muscle will shape the area. Also - ask patient to closeto contract medial pterygoid. - When finished - patient should be able to touchupper lip without much displacement of tray

CHAPTER 6

BORDER MOLDING AND FINAL IMPRESSIONSBORDER MOLDING A. OBJECTIVESStudents will be able to make a border of modeling compound on a shortened impression tray in relation to a patient's dentiform while observing anatomical landmarks.

B. EQUIPMENT/SUPPLIES1. Patient's dentiform 2. Final impression trays 3. Green stick compound 4. Vaseline 5. Alcohol Torch 6. Alcohol lamp 7. Knife

C. DIRECTIONS1. Lubricate dentiform with vaseline 2. Verify proper length of tray first on preliminary casts and then on patient dentiform 3. Borders should be 2mm short of

mucobuccal/mucolingual fold 4. Frenum attachments should be well relieved with "V" notches

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Maxillary Will be done in 8 sections:

1. Buccal space 2. Buccal frenum 3. Labial frenum 4. Buccal frenum 5. Buccal space 6. Hamular notch 7. Opposite hamular notch 8. Post dam area

Mandibular Suggested sections 1. Buccal Shelf 2. Buccal frenum 3. Labial Portion4. Buccal frenum 5. Buccal shelf 6. Distal border/ retromylohyoid area 7. Lingual flange 8. Sublingual crescent area 9. Lingual flange 10. Distal border/ retromylohyoid area

5. Hold stick of compound over flame. Twirl stick as compound is being heated. It is ready to use when stick first begins to slump. NOTE: If overheated, the compound will drip and flow in an uncontrolled manner. It must be kept under control. When melted it is extremely hot and likely to burn if it should contact skin.6. Add the softened compound carefully to the edge of tray building the compound to a height of 3-4mm above border of the tray. NOTE: After using desired amount of compound, chill the remainder of stick of softened compound in a bowl of cold water to prevent compound from sticking to the work bench. 7. Shape the compound with vaselined fingers. 8. Flame the compound with the alcohol torch, sweeping the flame back and forth.

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9. Temper the compound on tray (about 3 seconds). 10. Quickly seat the tray in place on the dentiform. Using a wet or vaselined finger, press the compound intoplace, molding it into the peripheral roll. 11. Remove - chill in water - examine for detail. 12. Use a knife to remove excess compound that has flowed inside the tray. NOTE: Remove compound from tuberosity areas but NOT from post dam area.13. Continue addition of compound until all areas/borders have been captured. Compound should be dull in order. Each new section should be smooth, rounded, andwell blended into previous sections.

Both Maxillary and Mandibular:14. Remove excess inside tray 15. Remove flash from outside tray (LAND area of dentiform). 16. Scrape very lightly a thin layer of compound from inside of compound border to prepare room for impression material.

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FINAL IMPRESSIONS A. OBJECTIVESThe student shall be able to select a proper material for a secondary impression, properly manipulate that material and make an acceptable secondary impressionusing that material.

B. EQUIPMENT/SUPPLIES1. Edentulous dentiform 2. Border molded custom trays 3. Mixing spatula 4. Glassslab 5. Final impression material 6. Knife

C. DIRECTIONS1. Examine border molded custom tray . 2. Correct any discrepancies before impression. 3. Relieve compound at the land areas and any excess that oozed inside the tray. NOTE: Your impression will be a "wash" type; basically intended to add tissue detail to an already border molded custom tray which has been extended into the height/depth of the fold areas. The less body or "carrying power" a material has, the more dependent it is upon support from the tray. Therefore, the accuracy of the impression depends on the accuracy of the tray. 4. Coat the inside of the tray as well as the borders. 5. Place equal amounts of base and catalyst materials on glass slab. 6. Using the edge of the spatula, incorporate the base and catalyst until thoroughly mixed and free of any color streaks. 7. Scrape allmaterial together in center of glass slab. 8. Lift all at once with spatula - twirling it as you approach tray to gather up any impression material that may betrailing from the spatula. NOTE: The fewer transfers the neater the job. Quick,decisive movements will result in better control of readily flowing materials. 3

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9. To load the tray, first load the border area by scraping the flat surface ofthe blade along the outside of the tray at the height of the border. Keep the blade in constant contact with the tray border. Pull the blade slowly downward with one hand as the tray is rotated in the other hand. 10. When the border is covered, wipe along the inside of the tray between border and ridge crest bilaterally. For maxillary, spread across the palate. NOTE: These movements serve to spread the material in the tray, to eliminate air bubbles, and to remove any excess material. 11. At this point, additional material may be added if necessary. A thin, unpenetrated layer of material should remain, as this is a "wash" type impression. 12. Excess material along the base of the dentiform can be removed with the edge of the spatula prior to final set. If material has set, excess can be removed with a sharp knife. 13. When material is set, grasp the tray handle and thebase of the dentiform and pull slowly apart. In some instances a gentle pry with a knife may be required. 14. Examine impression for accuracy of anatomy, lackof voids and bubbles, proper seating of tray, and pressure spots. Four voids less then 3mm in size in noncritical areas are acceptable. If large pressure spotsappear, make a note of their location, remove impression material, scrape compound to relieve pressure, and remake the impression. 15. If large voids appear orif tray has been improperly seated, remove impression material and D.I.O. (DO ITOVER).

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.

Boxing -- Maxillary and Mandibular1. A strip of boxing wax is wrapped around each beaded impression and sealed atall margins. The wax should be placed so as to create a cast base that is 1/2 to3/4 inch thick. Future procedures will be compromised if the bases are too thick.

Pouring Impressions:1. The impressions are poured in yellow dental stone that has been mixed at a ratio of 30ml/100gm.

Separating Impression from Casts:1. After stone is set (about 45 minutes) remove all wax. 2. Place casts in hot water to soften border molding compound. This will facilitate separation of impressions from casts. 3. Gently pry with knife at border of stone and plaster/pumice and separate the two. If more force is needed, rap the plaster./pumice portionwith a spatula handle to initially loosen cast, then tray again. The plaster nippers may also be used to remove the plaster/pumice.

TRIM THE MASTER CASTS so that:1. The bases are parallel to the projected plane of occlusion; 2. The bases are1/2 inch thick; 3. A minimum of 3mm of land area remains - are smooth and beveled; 4. Peripheral sulcus has been preserved; and 5. Grooves have been placed for

indexing.

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CUSTOM TRAYS A. DEFINITIONA Custom Tray is an individualized tray made from a cast recovered from a preliminary impression. It is used in making a final impression.

B. OBJECTIVES1. Recognize and discuss the significance of anatomical landmarks on the preliminary casts related to oral anatomy. 2. Describe and discuss the requirements ofa good final/custom impression tray as set forth in the evaluation criteria sheet. 3. Outline tray borders on casts prior to their construction and discuss thesignificance of that outline. 4. Perform the proper manipulation of self-polymerizing acrylic resin. 5. Identify those areas of the cast requiring relief. 6. List the various materials used to relieve a cast. Perform the cast relieving procedure. 7. Perform and describe the fabrication of a final/custom tray by adapting tray material to the cast and adding a tray handle during or following polymerization of the tray proper. 8. Perform the trimming and polishing and finish offinal/custom trays. 9. Be familiar with properties and characteristic of self-curing acrylic resin. 10. Be familiar with different types of custom impression trays. 11. Be familiar with the advantages and disadvantages of each of the abovetrays.

C. MATERIALS1. Diagnostic casts 2. Shellac Baseplate 3. Vaseline 4. Pink wax 5. Sharp knife6. Red/Blue pencil and scissors

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D. DIRECTIONSPart I: Outlining the casts: Maxillary: 1. Using the blue pencil, outline the depth of fold. Posteriorly the line extends from hamular notch to hamular notch, 2mm posterior to the fovea. 2. Using red pencil, draw a line 2mm short of the mucobuccal fold (the line of flexure of the mucous membrane as it passes from the maxilla or mandible to the cheek). Be certain to provide ample room for the frenum attachments. Posteriorly the red line should extend from hamular notch to hamular notch, COINCIDING with the blue line. Mandibular: 1. Using blue pencil, outline the depth of fold. 2. Using red pencil, draw a line 2 mm short to the mucobuccal fold... Start at the retromolar pad. Outline the distal extent of the pad line should coincide with the blue line at this point only. Carry the lateral endof the line to the external oblique ridge. Follow the ridge to about the 2nd bicuspid area. As you approach the 2nd bicuspid area, the outline leaves the ridgeand is continued 2 mm above the mucobuccal fold, to the same point on the opposite side. Remember to leave adequate room for frena. Lingually the tray outlineis 2mm short of the floor of the mouth. The distal-lingual border is obtained bydropping a line from the distal of the retromolar pad perpendicular to the floor of the mouth.REMEMBER: The outline of the tray is an educated approximation. Clinically, 1 impression are often more than 2 mm overextended. All trays are subject to refinement when tried in the mouth.

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Part II: Fabrication of shellac base plate trays:1. Forming the tray: Upon consultation with your instructor, it may be advisableto relieve the tray by use of a suitable material, e.g., ring liner material, wax or tinfoil. In general the following areas may require relief: a. Labial undercut on maxillary anterior ridge b. Slight buccal undercuts in the bicuspid region c. Tori d. Labial undercut on the mandibular ridge e. Retromylohyoid areas f.Areas of non-operable redundant tissue These may be relieved as necessary by one of the above fillers before the tray is fabricated. 1. Lubricate the cast withVaseline ( Petroleum jelly). Heat a pink wax and place it over the cast to serve as wax relief or wax spacer.

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2. Heat the shellac base plate and adapt it first in the palate and working peripherally over the ridge and into the fold areas of the cast. 3. For the lower, adapt the material on one side of arch first and move over the remaining portionof the arch. 4. Use a sharp knife to cut excess material beyond the land area ofthe cast.. 5. Excess material can be shaped into a tray handle and placed ontothe front of the tray in the shape to the LENGTH, WIDTH AND INCLINATION OF 2 CENTRAL INCISORS. The handle should be positioned just lingual to the crest of theridge, in the midline and so that it will not interfere with the lip or with border molding. Bind the material of the handle to make it smooth and wrinkle freeand flatten top handle of the tray.

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E. PROBLEMS AND ERRORS1. An incorrectly outlined model will result in a tray which is severely overextended or under-extended, either of which will complicate the final impression. 2. Excessively thick trays require much mechanical reduction and polishing at thechairside to make them useful in the mouth. 3. Excessively thin trays will be weak and distort in the final impression procedure. Thin trays may also break. 4.Incorrectly designed tray handles will prevent proper manipulation of the trayand interfere with accurate impression procedures. 5. Any imperfection on the internal surface of the tray is a reflection of an inaccurate cast.

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CHAPTER 7 CONSTRUCTION OF A STABLE RECORD BASE A. OBJECTIVE:The student will prepare the master cast for the construction of a "brush on" base plate, fabricate the base plates, and "accurately" fit this temporary base tothe master cast in a manner that will be stable in the mouth when transferred.

B. MATERIALS/SUPPLIES:1. 2. 3. 4. 5. 6. 7. Red/blue pencil Base plate wax Self-cured acrylic resin andliquid Vaseline Acrylic brush Acrylic bur Micromotor

C. PROCEDURE/DIRECTIONS:

Maxillary Cast:1. With instructors help, identify undercuts. 2. Fill all undercuts with base plate wax. Do not use heavy block out in the maxillary anterior area. 3. Lubricatethe cast with Vaseline ( Petroleum jelly). 4. Apply mixed resin on the cast, starting it first in the palate and working peripherally over the ridge and into the fold areas. 5. For the lower, apply the resin material on one side of arch first and moving over the remaining portion of the arch. 6. Use a sharp knife to cut excess material beyond the land area of the cast. Be careful not to stretch any of the peripheral resin. 7. Use an acrylic bur to remove any areas internallythat may be binding as the tray is placed on and off the cast.

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8. Use an acrylic bur on a micromotor to remove and trim excess material so thatit has a full peripheral roll for added stability.

DO NOT POLISH THE TISSUE (INTERNAL) SURFACE..

Mandibular Cast:Follow same procedure as for maxillary cast.

FABRICATION OF WAX OCCLUSION RIMS A. OBJECTIVE:The student will be able to construct occlusion rims on record bases in a mannerthat will enable him to restore facial contours for the edentulous patient.

B. MATERIALS/EQUIPMENT:1. Trail record bases 2. Master casts 3. Patient dentiform 4. Base plate wax 5.Sticky wax 6. Wax spatulas 7. Broad wax spatula/rim former 8. Alcohol lamp

C. DIRECTIONS:1. A bead of sticky wax is applied to the crest of the ridge of each trial record base. 2. A sheet of baseplate wax is warmed over the alcohol lamp 3. The wax is rolled after heating to make a log of wax. 4. The soft log of wax is bent andplaced on the trial record base, centered over the crest of the ridge. 5. A HOTspatula is used to seal the baseplate wax to the trial record base.

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6. While wax is still soft the cast should be inverted onto the glass slab to flatten the occlusal surface. 7. If necessary fill in the buccal/facial surface with wax to make it a solid Surface. 8. Use the broad wax spatula to smooth the facial and buccal surfaces of the occlusal rims. 9. The broad wax spatula is alsoused to flatten the occlusal surface of the occlusion rim. 10. The smaller wax spatulas are used to smooth the lingual surfaces of the occlusal rim. NOTE: The above procedures are used to fabricate both The maxillary and mandibular occlusion rims.

The DIMENSIONS of each rim are as follows: MAXILLARY:1. Terminate just anterior to the tuberosity 2. Occlusal plane parallel to baseof cast 3. 10mm high at molar area (measure from the outer surface of the Baseplate on top of the ridge, anterior to the tuberosity, to top of wax) 4. 22mm highat anterior (frenum to occlusal plane) 5. 10mm wide at molar area 6. 4mm wide at anterior area 7. 2-5 degree incisal flair 8. 45 degree angle at posterior end

MANDIBULAR:1. Terminate just anterior to retromolar pad 2. Occlusal plane parallel to baseof cast 3. Distal occlusal height even with 1/2 height of retromolar pad 4. 18mmhigh at anterior (frenum to occlusal plane) 5. 10mm wide at molar area 6. 4mm wide at anterior area 7. 2 degree incisal flair 8. 45 degree angle at posterior end Both rims should be given a final smoothing and finishing with the alcohol torch.

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Chapter 8 CLINICAL ADJUSTMENT OF CONTOUR RIMS & THE TENTATIVE REGISTRATION OF MAXILLO-MANDIBULAR RELATIONSA. DEFINITION: A tentative registration of the positional relationship of the mandibular arch to the maxillary arch in centric relation at a given vertical dimension. B. PURPOSE: 1. To establish the posterior extent of the maxillary denture. 2. To establish esthetic labial and buccal contours. 3. To establish the occlusal plane. 4. To mark the mid-line, high lip line, and cuspid-to-cuspid distance. 5. To mount the maxillary cast on the articulator in a manner which relates itto certain cranial landmarks. 6. To measure rest relations. 7. To register thevertical dimension of occlusion and centric relation.

C. INSTRUMENTS AND MATERIALS:1. Mouth mirror 2. Ball burnisher 3. Cleoid instrument 4. Alcohol torch 5. Hot plate 6. Bench knife 7. Dental floss

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In the Class II throat form, the posterior border will vary from 2 to 4 millimeters beyond the fovea palatini:

In the Class III throat form, the posterior border of the maxillary denture mustbe located at or close to the vibrating line:

Insert the maxillary contour rim and direct the patient to say "ahh" several times or blow as above. Study the relation of its posterior border and shorten it by scraping it with a sharp bench knife until it conforms to the above describedlength. The post-dam should vary in width and amount of pressure exerted according to the resiliency of the underlying tissues. The further posterior the denture will be extended, the greater will be the need for increasing the depth of thepost-dam. The greatest amount of resilient tissue lies between the pterygo-maxillary notch and the median line on each side. The underlying tissue at this point is ordinarily the belly of the tensor veil palatini muscle. The least resilient tissue is located in the median line area and is composed mainly of tendinoustissue. With the aid of an egg-shaped ball burnisher, record the degree of displaceability of the tissues in the patient

s mouth just anterior to the previouslydetermined posterior border of the maxillary denture. Test various points alongthis border from one pterygomaxillary notch to the other. Record the displaceability of the tissue as to width as well as depth at

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the various points. Divide the recorded measurements of displaceability along the posterior border by two and mark this figure on the cast at the various pointsalong the border. A typical post-dam picture on a cast would like the followingdiagram:

Place the contour rim which was place to determine posterior extension of the denture on the stone cast. With a sharp pencil or knife, trace the posterior border of the baseplate on the master cast. Remove the contour rim and draw the anterior termination of the postdam on the cast based upon observations of the displaceability in the mouth. Scrape the post-dam into the cast by means of the cleoidor other sharp suitable instrument, to follow these outlines, reducing the amount of scraping gradually toward the anterior border, so that at the anterior termination of the post-dam, the stone is cut to a minimum and blends with the unscraped palatal area of the cast. This procedure will also compensate for the palatal lift of the methyl methacrylate denture resulting from processing (See Dental Materials section.) Readapt the baseplate by adding Duralay acrylic in the manner taught in Preclinic lab (see sheet earlier in this manual). Reinsert the contour rim into the mouth and test its retention against anterior dislodging force. Its retention should be greatly improved.

2. Establishing Esthetic Labial and Buccal Contours:The final labial contour of the maxillary denture is established by altering that surface of the contour rim. With the maxillary contour rim in the patient

s mouth, observe the facial contours from both the front and side views. If necessar

y, recontour the facial surface of the rim until the desired contour is achieved. Observe the relationship of the rim to the relaxed upper lip.

3. The Occlusal Plane is next established using the following guidelines:a) The level of the anterior portion of the occlusal {plane usually extends 1 mmbelow the lower border of the relaxed upper lip}.

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b) The antero-posterior component of the plane is parallel to (but not at the same level as) a line drawn from the ala of the nose to the tragus of the ear (ala-tragus line). c) The lateral component of the plane is parallel to a line drawnbetween the pupils of the eyes (the interpupillary line). Trim or add wax to the contour rim to achieve this relationship. With the contour rim in the mouth, insert the Fox gauge against its occlusal surface. Study the relationship of theFox gauge to the interpupillary and ala-tragus lines. It should be trimmed or adjusted until it is parallel to both of these guidelines. Final adjustment to theguidelines is achieved by use of the hot plate.

4. Establishing the Midline, High Lip and Cuspid Line:With the maxillary contour rim in the patient

s mouth, study the face from a front view. Divide the philtrum of the lip and mark this point on the labial surface of the contour rim with a #7 spatula. This is the midline of the anterior segment. The distal surface of the natural maxillary canine is usually located nearthe corner of the mouth and a vertical line dropped from the ala of the nose tothe occlusal plane will often pass through the middle of the natural maxillary canine. These landmarks will provide an estimation of the position for the artificial canines and the width of six artificial teeth on a curve. Direct patient tosmile and make a horizontal mark at the lower border of the upper lip. This isthe high lip line. This mark is used to estimate the length of a maxillary central incisor.

5. To Measure Rest Relation:

In order to establish the proper interarch distance and the required interocclusal distance or Freeway Space of 2-4mm, it is necessary to study and measure restrelation of the mandible with respect to the maxilla. Rest relation is the postural relation of the mandible to the maxilla when the patient is resting comfortably in the upright position and the condyles are in a neutral unstrained position in the mandibular fossae. Cut two small triangles of tape and place one on the tip of the nose and the other on the chin at the midline so that their apicesface one another. Direct the patient to sit upright, free of any back or head support and relax. Insert the upper contour rim. Ask the patient to count slowly from 1 to 10. Then direct the patient to moisten the lips and swallow. Measure the distance between the apices of the tape with a ruler or a Boley gauge. Repeatthe measurement several times until a consistent result is obtained. Make sure that the position of the mandibular triangle is not influenced by the mentalis co

ntraction. Make a note of the rest position measurement. It will be used the registration of the vertical dimension of occlusion.

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6. To Register the Vertical Dimension of Occlusion (VDO) and Centric Relation (CR):Insert the mandibular occlusal rim and adjust its occluding surface until rest position is achieved. There should be uniform contact between the maxillary and the mandibular rims at this level. At this point it is often necessary to re-evaluate the previous tentative determination of the occlusal plane in order to permit proper placement of teeth. The occlusal plane may be altered bearing in mindthat the lateral orientation of the plane remains parallel to the interpupillaryline. The VDO is established by an arbitrary reduction of 2-3mm from the vertical dimension at rest relation. The Freeway Space is evaluated at this time. Lookat the "Closest Speaking Space" - when the patient makes "S", "SH" and "SH" sounds the posterior portions of the wax rims should just miss. If this is not thecase, the rims should be adjusted accordingly, keeping in mind anterior esthetics and the "fixed" height of the posterior mandibular rim. Remove 2mm of wax fromthe MANDIBULAR rim from the 1st bicuspid back on both sides and THEN make 2 small "V" notches. On the maxillary rim make 2 small nonparallel "V" notches on both sides and lightly vaseline. Soften Alu wax and place a "mound" on both sides of the mandibular posterior to a level at least 2mm higher than the occlusal plane. Insert wax rims in the patient

s mouth and guide the patient

s closure into Centric Relation. Remove the rims and mount the mandibular cast on the articulator.

Please Note: This procedure may have to be repeated as the patient frequently resists being guided into position until he understands what is being done. It is

wise to practice with the patient before the final registration is made.

E. PROBLEMS AND ERRORS1. When the posterior border of the maxillary denture is too short, the seal isreduced resulting in a less retentive denture. 2. When the posterior border of the maxillary is too long, the soft palate tissues are irritated and the seal isbroken by the movement of the soft palate. 3. When the cast is not cut deep enough for the posterior palatal seal, the denture will not make sufficient contactwith the tissues resulting in poor retention. 4. When the cast is cut too deeplyfor the posterior palatal seal the denture will displace the tissue excessivelyresulting in irritation of the related tissues. 5. When the labial surface of the contour rim is improperly formed the anterior teeth will be malpositioned resulting in a non-esthetic denture.

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6. When the occlusal plane is incorrectly oriented, the teeth will be incorrectly positioned resulting in 1) decreased stability in either or both dentures; 2)poor esthetics; 3) poor articulation. 7. When the VDO is excessive, the FreewaySpace is reduced or eliminated resulting in excessive pressure on the alveolar ridges and premature contacts of the teeth during nonmasticatory functions. 8. When the VDO is insufficient the Freeway Space is increased resulting in possibleTMJ disturbances, neuromuscular disorders and distortions of facial contours. 9.Incorrect CR will result in an occlusion of the teeth which is not in harmony with the proper position of the condyles in the mandibular fossae.

FACE BOW TRANSFER

MOUNTING THE MAXILLARY CAST

A. OBJECTIVE:The student shall be able to use the Whip Mix face bow instrument to register the relationship of the maxillary member of the typodont to the condylar analogueof the typodont, transfer that relationship to the articulator and mount the maxillary master cast on the articulator and mount the maxillary master cast on thearticulator using the face bow.

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B. MATERIALS / EQUIPMENT1. Whip Mix articulator 2. Face bow with accessories 3. Patient dentiform 4. Record bases & occlusal rims 5. Buffalo knife 6. Mounting plaster 7. Plaster bowl &spatula 8. Cast supporter 9. Red cake compound 10. Water Bath

C. DIRECTIONS:1. Mark the midline of the maxillary arch on the base of the dentiform with a pencil. 2. Place maxillary record base on the "patient" and score the wax rim at the midline. 3. Place notches, 2 each on either side between the 1st premolar area and end of wax rim, 2 mm. deep and 2 mm. wide. Lightly vaseline the notches. 4. Soften a cake of red compound in the water bath. Wrap the softened compound around the face bow fork. 5. Remove maxillary record base and invert the occlusalsurface onto the softened compound, lining up the midline in wax with the gold knob on the face bow fork. 6. Place record base with fork into "patient's mouth". 7. Attach bow to end of fork and attach the ear pieces to the ears of patient. 8.Attach the nasion indicator to the anterior of the bow and adjust it to the nose of the patient. Tighten screws, a little at a time, first one, then the other,then the first, then the second, until both are tightened firmly.

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9. Remove nasion indicator from face bow. 10. Remove face bow apparatus from patient. 11. Attach cast supporter and face bow supporter to lower member of articulator. 12. Attach face bow to its supporter on the articulator making certain the maxillary wax rim is centered from right to left between upper and lower halves of the articulator. 13. Place soaked and notched maxillary master cast into baseplate. 14. Check for adequate clearance of master cast superiorly and posteriorly. 15. Lightly vaseline ONLY THE NOTCHES of cast. 16. Attach maxillary cast toarticulator with mounting plaster. 17. Trim and smooth mounting plaster when set.

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CENTRIC RELATION RECORD AND MOUNTING OF MANDIBULAR CAST

PRE-CLINIC LABORATORY STEPS A. OBJECTIVES:The student will be able to record centric relation on the dentiform, transfer that recording to the articulator and mount the mandibular cast at the proper articulator settings.

B. DEFINITION:Centric relation is the most retruded relation of the mandible to the maxilla when the condyles are in their most posterior unstrained position in the glenoid fossa from which lateral movement can be made, at any degree of jaw separation. When a centric relation record is made there are three requirements that must always be fulfilled. They are: 1. The mandible should be in its correct horizontalrelationship to the maxilla.

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2. There should be equal bilateral vertical contact between the occlusion rims or opposing recording surfaces. The ideal recording medium is a freely-flowing material that will allow bilaterally equalized pressure. The material should be rigid and stable upon setting. Quick-setting plaster, ZnOE Bite Registration Pasteand Aluwax are three such acceptable mediums. 3. The relation record should becapable of being separated and rechecked in the mouth and must be stable and recognizably accurate in the horizontal, vertical and sagittal planes.

C. PROCEDURE:Wax is removed from the mandibular wax rim (2mm in depth) from the first bicuspid area back. The platforms on the mandibular rim are then scored with a knife sothe registration medium will adhere to these areas. The maxillary rim is then lubricated lightly with vaseline so that it will separate easily. Aluwax is thensoftened over a flame and/or in hot water, placed on mandibular platforms and built up to a level of at least 3 mm. above the occlusal plane. The dentiform is closed as the patient would close in the centric relation position and the aluwaxis allowed to harden. The aluwax should completely fill the maxillary grooves.After the wax is completely hard, excess wax is trimmed away from the registration area with a sharp knife. Remove both record bases (as a unit if possible). Place the maxillary base on the maxillary cast, invert the articulator, gently place the mandibular cast into the mandibular baseplate. Check to see that the relationship is stable, that the heels of the casts do touch and that there is sufficient clearance for mounting plaster.

PLEASE NOTE:1. Mandibular cast should be scored and soaked before it is mounted. 2. ALL ARTICULATOR SETTING SHOULD BE AT ZERO! 3. THE INCISAL PIN SHOULD BE AT ZERO! 4. THEINCISAL PIN SHOULD TOUCH THE INCISAL TABLE!

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POSTERIOR PALATAL SEAL / POST DAM

A. OBJECTIVESTo be able to define a post dam, list its purpose and list its types in writing.To be able to answer questions about the former on a written exam. To be able to prepare a post dam on the pre-clinic laboratory cast and baseplate and on a clinical case. To be able to demonstrate or delineate the post dam area on a patient.

B. EQUIPMENT / MATERIALS:1. Patient dentiform 2. Maxillary master cast 3. Maxillary record base and occlusal rime 4. #8 round laboratory carbide bur 5. Duralay 6. Dappen dishes 7. Foilcoat 8. Paint brush 9. Buffalo knife 10. Cleoid-discoid 11. Laboratory acrylic bur 12. Color transfer sticks

C. DIRECTIONS:1. Using color transfer applicator draw terminal edge of denture in "patient

s"mouth from hamular notch to hamular notch at the vibrating line. 2. Place recordbase on patient. The purple line should be transferred onto the record base. 3.The record base is trimmed back to the line. 66


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4. Place record base on the master cast. 5. Scribe a line in cast along terminaledge of record base. 6. Draw gull wing shape in palate of "Patient" as described in lecture. 7. Replace record base on "patient" and transfer gull wing shape onto it. 8. Place record base back onto master cast and transfer gull wing shapeonto cast. 9. Remove record base. 10. Using #8 round bur in the slow speed handpiece, re-scribe terminal line of post dam to a depth of 1 to 1 1/2 mm. 11. Usingthe cleoid-discoid carve post dam area by removing stone from the outlined area. 12. REMEMBER: The post dam is deepest in the posterior and should fade to a feather edge anteriorly. 13. The entire area should then be smoothed with the backend of the Buffalo knife. 14. Paint the posterior area of the master cast withfoilcoat and let it dry. 15. Build up the post dam area with Duralay. 16. Paintthe posterior portion of the record base with Duralay monomer. 17. Seat the record base solidly and firmly on the master cast. 18. Allow Duralay to set. 19. Remove the record base and inspect the post dam. 20. Remove flash around the anterior portion with a knife. 21. Trim along the posterior portion with acrylic bur.

REMEMBER! Your "patient" does not have compressible tissue. Do not try to forcethe record base on. This exercise was only to demonstrate how a post dam is added to an acrylic record base. Before continuing on to the next phase of denture fabrication, the Duralay post dam must be removed with an acrylic bur. 67


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Chapter 9ARTIFICIAL TEETH - GENERAL DISCUSSION A. DEFINITION:Denture teeth are artificial substitutes for the coronal portions of the missingteeth. They are usually made of porcelain or plastic. Porcelain denture teeth contain various retentive devices such as platinum-iridium pins and diatoric holes, to secure them to the plastic denture base.

B. PURPOSE:To select the proper anterior and posterior denture teeth which will fulfill theesthetic and functional requirements of the patient.

C. INSTRUMENTS and MATERIALS:1. Occlusion and contour rims 2. Tooth mold and shade guides 3. Flexible ruler 4. Large hand mirror

D. PROCEDURE:

1. The maxillary anterior denture teeth are selected according to size, shape, shade and material. a. Size:Insert the maxillary occlusion and contour rim which was used to establish the tentative vertical dimension and centric relation. If the contour rim lacks retention, it is advisable to use denture adhesive. With the patient

s facial musculature relaxed, indicate the midline of the face on the labial aspect by inscribing a line parallel to the mid-sagittal plane of the head with a #7 spatula. This

line usually bisects the philtrum of the upper lip. It does NOT ALWAYS coincidewith the labial frenum.

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Establish the level of the high lip line on the contour rim by asking the patient to smile broadly. This will aid in the determination of the tooth length. Thewidth of the six maxillary anterior teeth is determined by using the following methods: 1) by dropping a perpendicular from the lateral surface of the ala of the nose. This indicates the center of the cuspid. 2) By marking the corner of themouth with the lips relaxed on the contour rim with the #7 spatula. This indicates the distal of the cuspid. 3) By dropping a perpendicular midway between theala of the nose and the pupil of the eye and marking it with the #7 spatula on the contour rim. This may also indicate the distal of the cuspid. These guides are used as a starting point for the selection

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77236914 Study Guide Treatment of Edentulous Patients

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