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Tissue Management & Impression Techniques for Fixed Prosthodontics

Khaled Q Al Hamad BDS MSc MRD RCSEd Assistant Professor, Faculty of Dentistry 1 Jordan University Of Science & Technology

Tissue management Impression techniques

8 April 09

Tissue Management and Impression Techniques for Fixed Prosthodontics

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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

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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 20048 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 4

Impressions not accurately recording the gingival finish lines Not reproducible finish line Inadequate restorations Open margins Overhangs

Inflamed gingival inflammation and/or recession Increased PD 8 April 09Tissue Management and Impression Techniques for Fixed Prosthodontics

Loss of CAL

Bone resorption 5

Tissue Displacement

The deflection of the marginal gingiva away from the tooth

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Academy of Prosthodontics. Glossary of Prosthodontic Terms Glossary of 2005 6 Tissue Management and Impression Techniquesfor Fixed Prosthodontics

Tissue Displacement PurposesCreate sufficient lateral and vertical space between the gingival finish line and the gingival tissue Provide absolute control of gingival fluid seepage and hemorrhageNemetz et al 1984 NemetzTissue Management and Impression Techniques for Fixed Prosthodontics 7

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Ideal Retraction Material Characteristics

Effective for its intended use Should not cause significant and irreversible tissue damage Should not produce potentially harmful systemic effectsDonovan et al 1985 8 Tissue Management and Impression Techniquesfor Fixed Prosthodontics

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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

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TechniquesMechanical Methods Chemomechanical Methods Retraction cords Retraction cord+ Haemostatic agents Surgical Methods Electro surgery Rotary gingival curettage Combination of these8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 10

Retraction cordsTraditionally been the most popular method

Safe 98% of respondents Easy gingival used retraction cords, with Quick 44% of them using a Effectivecord plain Inexpensiv Hansen 2007 Poss 2007 Hansen et 1999 Poss et 19998 April 09

e

Tissue Management and Impression Techniques for Fixed Prosthodontics

Ferencz 1991 1991

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Gingival retraction cord may damage the periodontal tissues

Liu et al 2004 al 2004

Tissue damage may occur, with friable thin gingival tissue particularly susceptible and subject to Poss tearing 200712

8 April 09

Tissue Management and Impression Techniques for Fixed Prosthodontics

Factors Affecting Damage

Force used in packing the cord Size or Number of retraction cords Length of time the cord is left inplace within the sulcus

Chemical agent with which thecord has been impregnated8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics

Ferencz 1991 Ferencz 1991 Goodacre 1990

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If the gingiva is healthy initially, healing will occur rapidlyYap & Ong Yap & Ong 1994

Took about 8 days to heal, but with average postoperative gingival recession of about 0.2 - 0.1 mmRuel et al. 1980 . 1980

Healing occurred histologically in 7 to 10 daysGoodacre 1990 Goodacre 1990

The damage healed clinically within two weeks as was indicated by the GI8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics

Feng et al. 2006 Feng et al. 200614

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

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Haemostatic Agent-epinephrine -potassium aluminum sulfate (ALUM) -aluminum chloride (Hemodent) -ferric sulfate -zinc chloride -tetrahydrozoline

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Tissue Management and Impression Techniques for Fixed Prosthodontics

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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 effects8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 17

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

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Cordless Techniques Expasyl

Magic Foam Cord

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Tissue Management and Impression Techniques for Fixed Prosthodontics

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Expasyl

(Kerr cooperation, Orange, Kerr cooperation, CA) )

Viscous paste acts as a chemomechanical haemostatic and retraction agent Component

Organic,Easy and quick tissue displacement clay material (kaolin) Aluminum chloride Hemostatic agent (15%) Additional ingredients include colorants, Soll 2001 20 Tissue Management and Impression Techniques 8 April 09 water, and essential oil of lemon for Fixed Prosthodontics

ExpasylCartridge Form Stainless Steel Dispenser Disposable Tips

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Tissue Management and Impression Techniques for Fixed Prosthodontics

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Technique PrincipleThe strength of the epithelial attachment is 1 N/ mm2 Injured by the application of a pressure of 2.5 N/ mm2 Pressure of 0.1 N/mm2 enable sulcus opening of 1.5 mm & a delayed recovery up to 2 minutes per 0.5 mm opening Too low to damage Sufficient to obtain sulcus openingLesage 2002 20028 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 22

Efficacyhas yet to be established

8 April 09

Tissue Management and Impression Techniques for Fixed Prosthodontics

Donovan & Chee 2004 Donovan

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Magic Foam CordColtne/Whaledent Coltne/Whaledent

The first expanding PVS material designed for easy and fast retraction of the sulcus

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Tissue Management and Impression Techniques for Fixed Prosthodontics

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Magic Foam CordColtne/Whaledent Coltne/Whaledent

Cartridge similar to the regular impression materials Disposable tips Cotton cap (Comprecap) Used with the same gun of the regular addition silicone impression material8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 25

Principle of WorkSilicone foam expands in the sulcus and its mass becomes larger precisely to achieve the retraction we require

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Tissue Management and Impression Techniques for Fixed Prosthodontics

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Effect on gingival health Efficiency in gingival retraction

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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:

10531058.

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 bleeding8 April 09 Tissue Management and Impression Techniques for Fixed Prosthodontics 28

Part I: tissue management Tissue management Aims and principles Techniques Mechanical Chemo mechanical Surgical Comb