Presentation on theme: "Composite Resin Material"— Presentation transcript:
1 Composite Resin Material Part 11Dr. Nesrien Ateyah
2 Introduction: There were considerations regarding various properties of composites for successful composite restoration to be done. These properties generally require specific technique in the restorative proceduresCavity preparation Application of the material
3 Cavity preparations should be conservative as possible. The extent of the preparation is usuallydetermined by :Size Shape Locationof the defect
4 The extension should provide access for vision and instrumentation. The strong bond which is developed b/w: the etch enamel bonding agent compositeThis will promotes a strong indication for direct composites restoration to be used.
5 Acid Etch Phenomenon Developed by Buonocore in 1955. Technique consists of:1. Applying a solution or gel of 30 – 50 % phosphoric acid to enamel for 20 sec.to dentin for 30 sec2. Thorough rinsing with water for 20 sec.3. Drying the area with air free oil for5 Sec.
6 Acid Phenomenon (cont’n) Acid solution affect the prismatic structure of the enamel by preferential removal of eitherPrism core Prism Both Prism(I) Periphery core , periphery(II) (III)
7 This process results in an enamel surface characterized by: Acid PhenomenonThis process results in an enamel surface characterized by:1) Numerous microscopic undercuts2) Irregular surface in the enamel.
8 Acid Etch Effect Provide a higher surface energy to enhance surface area for bonding. Provide a higher surface energy to enhancewetting contact angle good bondingDemineralized porous enamel rod end (5-50Mm )The resin can penetrate and producemechanical tags (mechanical interlock)
9 Acid Etch Effect Depend on Kind of acid used. Acid concentration. Etching Time. Form of etching (gel, semi gel, solution) Rinsing Time. Way of Etching. Enamel Instrumented b / f etchant. Enamel of primary or permanent teeth. Enamel is stained,demineralized or flouridated.
10 Enamel / Dentin Bonding System Bonding agents - Resins with low viscosityused for the adhesion to enamel or dentin. Acid etching + fluid resin bonding agentthe basis for the1) Retention2) Marginal seal against microleakage of the composite resin restoration placed in cavity preparation involving enamel margins.
11 Enamel/Dentin Bonding System Dentin can be pre-treated like enamel toproduce a surface that is more retentive. Dentin bonding system consists of:1. Conditioning agent - to remove asmear layer (dentin debris)2. Low viscosity hydrophilic resin primer to ensure optimal wetting and bonding to the hydrated dentinal surface.
12 Enamel/Dentin Bonding System 3. Resin adhesive bonding agent [Unfilled resin (adhesive) BisGMA]applied to dentinoretched enamel
13 Acid Etching _ Remove 10Mm of enamel surface Conditioner _ Remove smear layer Primer _ Stabilize collagen and facilitatepenetration of bonding resin
14 Factors Affecting the Adhesive Bond Water. Saliva. Inadequate removal of acid etching.
16 Restorative Procedures: (cont’n) Bonding• brush• light air• cure 20 sec. Dry field if saliva or sulcular sweep age • reapply the acid• contact the preparation• etchant 10 sec• wash and dry.
17 Restorative Procedures: Matrix application aid in:• placing composite resin• contouring• reduce excess• minimize finishing time
18 Restorative Procedures: Two types of matrices• Polyester strip matrix• Compound supported metal matrixIII, IV cavity preparations.Shape the strip to the desired tooth contour.
19 2) To provide slight separation of the teeth. Restorative Procedures:Apply a wedge at the gingival margin:1) Help to hold the strip in position.2) To provide slight separation of the teeth.3) To prevent a gingival overhang of the composite resin material.Wedge placed from the facial approach for lingual access cavities (vice versa).
20 using hand instrument [plastic instrument] Light cure 40 sec. Application of composite using hand instrument[plastic instrument] Light cure 40 sec.
21 Finishing Technique for Composite Good technique and experience in inserting composite reduce the amount of finishing required.1) Flame shaped finishing bur removing excess and contouring
22 2)Sandpaper disc degree of abrasive. depend on the. amount of excess 2)Sandpaper disc degree of abrasive depend on the amount of excess to be removed.
23 4) Pop-on discs and mandrel 3) Sof-Lex discs• for contouring and polishing• flexible• several diameter and abrasive textures.4) Pop-on discs and mandrel• small diameter• placed, removed without the need for proper orientation.• will fit into embrasure areas.• useful in contouring and polishing gingival area.
24 6) Finishing strip (medium and fine) for • final contouring 5) No 12 surgical blade to remove inter proximal excess6) Finishing strip (medium and fine)for• final contouring• finishing of proximal surfaceShould be curved over the restoration.
25 7) Rubber polishing point 8) Aluminum oxide polishing paste for final polishing..
26 Occlusion: Remove the rubber dam Evaluate occlusion by having the patient close lightly on the articulating paper if excess is present, remove only a small amount at a time and recheck.