1
Tissue Management & Impression Techniques for Fixed Prosthodontics
Khaled Q Al HamadBDS MSc MRD RCSEd
Assistant Professor, Faculty of DentistryJordan University Of Science & Technology
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
2
Tissue management
Impression techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
3
Part I: tissue management
Tissue management Aims and principles Techniques
Mechanical Chemo mechanical Surgical Combination
Haemostatic agents New cordless techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
4
The impression should provide a precise and clear model of the prepared tooth and the surrounding tissues for the technician to fabricate an accurate dies and to produce a biologically, functionally and esthetically satisfactory fit restoration
The impression should provide a precise and clear model of the prepared tooth and the surrounding tissues for the technician to fabricate an accurate dies and to produce a biologically, functionally and esthetically satisfactory fit restoration
Donovan & Chee 2004 Donovan & Chee 2004
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
5
Impressions not accurately recording Impressions not accurately recording the gingival finish lines the gingival finish lines
Impressions not accurately recording Impressions not accurately recording the gingival finish lines the gingival finish lines
Not reproducible finish line Not reproducible finish line
Inflamed gingival Inflamed gingival inflammation and/or inflammation and/or
recessionrecession
Inflamed gingival Inflamed gingival inflammation and/or inflammation and/or
recessionrecession
Inadequate restorationsInadequate restorationsInadequate restorationsInadequate restorations
Open marginsOpen marginsOpen marginsOpen margins OverhangsOverhangsOverhangsOverhangs
Loss of CALLoss of CALLoss of CALLoss of CALIncreased PDIncreased PDIncreased PDIncreased PD Bone resorptionBone resorptionBone resorptionBone resorption
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
6
Tissue DisplacementTissue Displacement
Academy of Prosthodontics. Academy of Prosthodontics. Glossary of Prosthodontic Terms Glossary of Prosthodontic Terms
20052005
Academy of Prosthodontics. Academy of Prosthodontics. Glossary of Prosthodontic Terms Glossary of Prosthodontic Terms
20052005
““The deflection of the The deflection of the marginal gingiva away from marginal gingiva away from
the tooth” the tooth”
““The deflection of the The deflection of the marginal gingiva away from marginal gingiva away from
the tooth” the tooth”
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
7
Tissue Displacement Tissue Displacement PurposesPurposes
Tissue Displacement Tissue Displacement PurposesPurposes
Create sufficient lateral and vertical Create sufficient lateral and vertical space between the gingival finish line space between the gingival finish line and the gingival tissueand the gingival tissue
Create sufficient lateral and vertical Create sufficient lateral and vertical space between the gingival finish line space between the gingival finish line and the gingival tissueand the gingival tissue
Nemetz et al 1984 Nemetz et al 1984 Nemetz et al 1984 Nemetz et al 1984
Provide absolute control of gingival Provide absolute control of gingival fluid seepage and hemorrhagefluid seepage and hemorrhageProvide absolute control of gingival Provide absolute control of gingival
fluid seepage and hemorrhagefluid seepage and hemorrhage
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
8
Ideal Retraction Material CharacteristicsIdeal Retraction Material Characteristics
Should not cause significant and Should not cause significant and irreversible tissue damageirreversible tissue damage
Should not cause significant and Should not cause significant and irreversible tissue damageirreversible tissue damage
Effective for its intended useEffective for its intended use Effective for its intended useEffective for its intended use
Should not produce potentially Should not produce potentially harmful systemic effectsharmful systemic effects
Should not produce potentially Should not produce potentially harmful systemic effectsharmful systemic effects
Donovan et al Donovan et al 19851985
Donovan et al Donovan et al 19851985
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
9
Part I: tissue management
Tissue management Aims, purposes and principles Techniques
Mechanical Chemo mechanical Surgical Combination
Haemostatic agents New cordless techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
10
Techniques Techniques
Mechanical Mechanical MethodsMethods
Retraction cordsRetraction cords
Mechanical Mechanical MethodsMethods
Retraction cordsRetraction cordsChemomechanical MethodsChemomechanical MethodsRetraction cord+ Haemostatic agents Retraction cord+ Haemostatic agents
Chemomechanical MethodsChemomechanical MethodsRetraction cord+ Haemostatic agents Retraction cord+ Haemostatic agents
Surgical Methods Surgical Methods Electro surgeryElectro surgeryRotary gingival curettageRotary gingival curettage
Surgical Methods Surgical Methods Electro surgeryElectro surgeryRotary gingival curettageRotary gingival curettage
Combination of theseCombination of theseCombination of theseCombination of these
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
11
Retraction cordsRetraction cords
Traditionally been the most popular Traditionally been the most popular methodmethodTraditionally been the most popular Traditionally been the most popular methodmethod
98% of respondents 98% of respondents used gingival used gingival
retraction cords, with retraction cords, with 44% of them using a 44% of them using a
plain cordplain cord
98% of respondents 98% of respondents used gingival used gingival
retraction cords, with retraction cords, with 44% of them using a 44% of them using a
plain cordplain cord
Hansen et 1999Hansen et 1999Hansen et 1999Hansen et 1999
SafeSafeSafeSafe
EasyEasyEasyEasy
QuickQuickQuickQuick
Effective Effective
InexpensivInexpensivee
InexpensivInexpensivee
Poss 2007 Poss 2007 Ferencz 1991 Ferencz 1991
Poss 2007 Poss 2007 Ferencz 1991 Ferencz 1991
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
12
““Gingival Gingival retraction retraction cord may cord may
damage the damage the periodontal periodontal
tissues”tissues”
““Gingival Gingival retraction retraction cord may cord may
damage the damage the periodontal periodontal
tissues”tissues”Liu et al 2004Liu et al 2004 Liu et al 2004Liu et al 2004
““Tissue Tissue damage may damage may occur, with occur, with friable thin friable thin
gingival tissue gingival tissue particularly particularly
susceptible and susceptible and subject to subject to tearing”tearing”
““Tissue Tissue damage may damage may occur, with occur, with friable thin friable thin
gingival tissue gingival tissue particularly particularly
susceptible and susceptible and subject to subject to tearing”tearing”Poss 2007Poss 2007Poss 2007Poss 2007
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
13
Factors Affecting DamageFactors Affecting DamageFactors Affecting DamageFactors Affecting Damage
Ferencz 1991Ferencz 1991Ferencz 1991Ferencz 1991Goodacre 1990 Goodacre 1990 Goodacre 1990 Goodacre 1990
Force Force used in packing the cordused in packing the cordForce Force used in packing the cordused in packing the cord
SizeSize or or NumberNumber of retraction cords of retraction cordsSizeSize or or NumberNumber of retraction cords of retraction cords
Length of Length of timetime the cord is left in the cord is left in place within the sulcusplace within the sulcusLength of Length of timetime the cord is left in the cord is left in place within the sulcusplace within the sulcus
ChemicalChemical agent with which the agent with which the cord has been impregnatedcord has been impregnatedChemicalChemical agent with which the agent with which the cord has been impregnatedcord has been impregnated
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
14
If the gingiva is healthy initially, healing If the gingiva is healthy initially, healing will occur will occur rapidlyrapidlyIf the gingiva is healthy initially, healing If the gingiva is healthy initially, healing will occur will occur rapidlyrapidly
Took about Took about 8 days8 days to heal, but with average to heal, but with average postoperative gingival recession of about 0.2 postoperative gingival recession of about 0.2 - 0.1 mm- 0.1 mm
Took about Took about 8 days8 days to heal, but with average to heal, but with average postoperative gingival recession of about 0.2 postoperative gingival recession of about 0.2 - 0.1 mm- 0.1 mm
Ruel et alRuel et al. . 19801980Ruel et alRuel et al. . 19801980
The damage healed clinically within The damage healed clinically within two two weeksweeks as was indicated by the GI as was indicated by the GIThe damage healed clinically within The damage healed clinically within two two weeksweeks as was indicated by the GI as was indicated by the GI
Feng et alFeng et al. . 20062006 Feng et alFeng et al. . 20062006
Yap & Ong Yap & Ong 19941994
Yap & Ong Yap & Ong 19941994
Healing occurred histologically in Healing occurred histologically in 7 to 10 days7 to 10 daysHealing occurred histologically in Healing occurred histologically in 7 to 10 days7 to 10 days
Goodacre 1990Goodacre 1990Goodacre 1990Goodacre 1990
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
15
Part I: tissue management
Tissue management Aims and principles Techniques
Mechanical Chemo mechanical Surgical Combination
Haemostatic agents New cordless techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
16
Haemostatic Agent
-epinephrine-potassium aluminum sulfate (ALUM)-aluminum chloride (Hemodent)-ferric sulfate-zinc chloride-tetrahydrozoline
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
17
epi (0.1%-0.8%): -creates local vasoconstriction -a 1 inch of cord with 1.0mg of epi contains 2.5x the max dose for healthy patients and 12x the dose recommended for cardiac patients -contraindications for epi use in cord: hx of cardiovascular disease, hyperthyroidism, allergy to epi -signs of epi syndrome: tachycardia, increase in respirations, nervousness, increase in B.P., post op. depression---these symptoms will appear after the cord has been in place for a few minutes or shortly after it is removed. -ALUM (potassium aluminum sulfate): -only slightly less effective than epi at shrinking tissues -Hemodent (aluminum chloride):5-10%: -conc in excess of 10% will cause local tissue destruction -there are no major contraindications and minimal systemic effects -Ferric sulfate (13.3%): -astringent -very good for hemostasis -does not noticeably traumatize tissues and heal more rapidly than hemodent -temporarily discolors tissues for 1-2 days -provides tissue displacement for at least 30min -Zinc chloride (Bitartrate):8% & 40%: -tissue displacement equal to epi -* tissue necrosis is high -NOT RECOMMENDED FOR USE -Tetrahydrozoline (visine, afrin, murine plus, neosynephrine) -a sympathomimetic amine that produces vasoconstriction with minimal side effects
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
18
Part I: tissue management
Tissue management Aims and principles Techniques
Mechanical Chemo mechanical Surgical Combination
Haemostatic agents New cordless techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
19
Cordless TechniquesCordless TechniquesCordless TechniquesCordless Techniques
Expasyl®Expasyl®
Magic Foam Magic Foam Cord®Cord®
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
20
ExpasylExpasylExpasylExpasyl
Viscous paste acts as a chemo-Viscous paste acts as a chemo-mechanical haemostatic and retraction mechanical haemostatic and retraction agentagent
ComponentComponentOrganic, clay material (kaolin)
Aluminum chloride (15%)
Additional ingredients include colorants, water, and essential oil of lemon
Viscous paste acts as a chemo-Viscous paste acts as a chemo-mechanical haemostatic and retraction mechanical haemostatic and retraction agentagent
ComponentComponentOrganic, clay material (kaolin)
Aluminum chloride (15%)
Additional ingredients include colorants, water, and essential oil of lemon
Soll 2001Soll 2001
((Kerr cooperation, Orange, Kerr cooperation, Orange, CACA) ) ((Kerr cooperation, Orange, Kerr cooperation, Orange, CACA) )
Easy and quick tissue displacementEasy and quick tissue displacementEasy and quick tissue displacementEasy and quick tissue displacement
Hemostatic agentHemostatic agent
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
21
ExpasylExpasylExpasylExpasyl
Cartridge Form Cartridge Form
Stainless Steel Dispenser Stainless Steel Dispenser
Disposable TipsDisposable Tips
Cartridge Form Cartridge Form
Stainless Steel Dispenser Stainless Steel Dispenser
Disposable TipsDisposable Tips
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
22
Technique PrincipleTechnique Principle
Lesage 2002Lesage 2002Lesage 2002Lesage 2002
The strength of the epithelial attachment The strength of the epithelial attachment is is 1 N/ mm21 N/ mm2
Injured by the application of a pressure of Injured by the application of a pressure of 2.5 N/ mm22.5 N/ mm2
Pressure of Pressure of 0.1 N/mm20.1 N/mm2 enable sulcus enable sulcus opening of opening of 1.5 mm1.5 mm & a delayed recovery up & a delayed recovery up to to 2 minutes per 0.5 mm2 minutes per 0.5 mm opening opening
The strength of the epithelial attachment The strength of the epithelial attachment is is 1 N/ mm21 N/ mm2
Injured by the application of a pressure of Injured by the application of a pressure of 2.5 N/ mm22.5 N/ mm2
Pressure of Pressure of 0.1 N/mm20.1 N/mm2 enable sulcus enable sulcus opening of opening of 1.5 mm1.5 mm & a delayed recovery up & a delayed recovery up to to 2 minutes per 0.5 mm2 minutes per 0.5 mm opening opening
Sufficient to obtain Sufficient to obtain sulcus openingsulcus openingSufficient to obtain Sufficient to obtain sulcus openingsulcus openingToo low to damageToo low to damageToo low to damageToo low to damage
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
23Donovan & Chee 2004Donovan & Chee 2004Donovan & Chee 2004Donovan & Chee 2004
EfficacyEfficacyEfficacyEfficacyhas yet to be establishedhas yet to be establishedhas yet to be establishedhas yet to be established
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
24
Magic Foam CordMagic Foam CordMagic Foam CordMagic Foam CordColtène/Whaledent Coltène/Whaledent Coltène/Whaledent Coltène/Whaledent
The first expanding PVS The first expanding PVS material designed for easy material designed for easy and fast retraction of the and fast retraction of the
sulcussulcus
The first expanding PVS The first expanding PVS material designed for easy material designed for easy and fast retraction of the and fast retraction of the
sulcussulcus
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
25
Cartridge similar to the regular Cartridge similar to the regular impression materialsimpression materials
Disposable tipsDisposable tips
Cotton cap (Comprecap)Cotton cap (Comprecap)
Used with the same gun of the Used with the same gun of the regular addition silicone impression regular addition silicone impression materialmaterial
Cartridge similar to the regular Cartridge similar to the regular impression materialsimpression materials
Disposable tipsDisposable tips
Cotton cap (Comprecap)Cotton cap (Comprecap)
Used with the same gun of the Used with the same gun of the regular addition silicone impression regular addition silicone impression materialmaterial
Magic Foam CordMagic Foam CordMagic Foam CordMagic Foam CordColtène/Whaledent Coltène/Whaledent Coltène/Whaledent Coltène/Whaledent
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
26
Silicone foam expands in the Silicone foam expands in the sulcus and its mass becomes sulcus and its mass becomes
larger precisely to achieve the larger precisely to achieve the retraction we requireretraction we require
Silicone foam expands in the Silicone foam expands in the sulcus and its mass becomes sulcus and its mass becomes
larger precisely to achieve the larger precisely to achieve the retraction we requireretraction we require
Principle of Principle of WorkWork
Principle of Principle of WorkWork
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
27
Effect on gingival health Effect on gingival health
Efficiency in gingival Efficiency in gingival retractionretraction
Effect on gingival health Effect on gingival health
Efficiency in gingival Efficiency in gingival retractionretraction
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
28
A clinical study on the effects of cordless and conventional retraction techniques on the gingival and periodontal health.
Al Hamad et al., J Clin Periodontol 2008; 35: 1053–1058.
Principal findings: all retraction techniques caused a temporary inflammation, measured through the gingival index.The recovery at 7 days was slower for Expasyl. Bleeding during or after retraction was only encountered with the use of conventional retraction cords.
Practical implications: This study showed that none of the techniques tested seems to harm the tissues in the long term; however, clinicians should be aware that Expasyl use is less friendly to the gingival tissues. Cordless techniques do not require haemostatic agents to control bleeding
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
29
Part I: tissue management
Tissue management Aims and principles Techniques
Mechanical Chemo mechanical Surgical Combination
Haemostatic agents New cordless techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
30
Lecture Outline
Tissue management
Impression techniques
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
31
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
32
Classification: Elasticity
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
33
Viscosity
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
34
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
35
Polysulphide Base:
Short chain Thiokol polymer. Used extensively in building industry where it is supplied as
a one pack and setting takes place under atmospheric oxygen (weeks).
In dentistry, setting is brought about by oxidizing agent (lead dioxide)
Molecule of water is produced for every link that is made. (condensation)
Objectionable odor Long setting time High shrinkage High tear resistance High permanent deformation
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
36
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disnfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
37
Polyether Base
Polyether polymer with imine group Plasticizer & Inert filler
Activator Aromatic Sulphonate Plasticizer & Inert filler
Short working time Less permanent deformation than polysulfide but not as
low as silicones. Stiff The least dimensional change except the addition type
silicone. Absorb water.
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
38
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
39
Silicone Rubber
Condensation Type Base:
Hydroxyl terminated Dimethyl siloxane (reactive OH). Catalyst:
Alkyl silicate. Different viscosities produced by different MW of Dimethyl
siloxane and the concentration of the filler. Condensation reaction producing alcohol. Resulting in
dimensional change occuring mainly during the first 24 h. Addition Type
Prepolymer of polydimethyl siloxane in which some of the methyl groups are replaced by vinyl groups in one paste and with hydrogen in the other paste.
Catalyst: Platinum containing compound (chloroplatinic acid). Addition reaction producing no by products. Increase in Temperature and Moisture increases the reaction. Early when they first introduced(1950’s) gaseous hydrogen
was produced as a result of the cross linking reaction. Mechanism is unclear !(side reaction of the hydroxil group ? Or a reaction of the catalyst with moisture??)
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
40
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
41
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
42
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
43
Comparison of elastomers
Setting time - Polysulfides > Silicones > Polyethers
Tear strength - Polysulfides > Silicones > Polyethers
Stiffness - Polyethers > Silicones > Polysulfides
Dimensional Change - Cond Silicone > Polysulfides > Polyethers > Addition Silicone
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
44
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
45
Materials
Polyvinylsiloxane impression material
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
46
Trays
Stainless steel perforated trays(metal)Polytrays (Polycarbonate/Yellow)Orthodontic impression trays(red)
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
47
Part II: Impression Techniques
Classifications Available materials
Polysulphide Polyether Silicones
Condensation-type Addition-type
Comparisons
Packaging & Techniques Disinfection
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
48
Disinfection DISINFECTANTS FOR IMPRESSION
MATERIALS: Glutaraldehyde: - Indicated for all impression materials
except hydrocolloids Phenols: - Indicated for polysulfide rubber base
only Iodophors and NaOCl: - Indicated for all impression materials
8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics
49
Clinical Case