1. Composite Resin Material
Part 11
Dr. 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 procedures
Cavity preparation Application of the material

3.  Cavity preparations should be conservative
as possible.
 The extent of the preparation is usually
determined by :
Size Shape Location
of 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
 composite
This 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 sec
2. Thorough rinsing with water for 20 sec.
3. Drying the area with air free oil for
5 Sec.

6. Acid Phenomenon (cont’n)
Acid solution affect the prismatic structure of the enamel by preferential removal of either
Prism core Prism Both Prism
(I) Periphery core , periphery
(II) (III)

7. This process results in an enamel surface characterized by:
Acid Phenomenon
This process results in an enamel surface characterized by:
1) Numerous microscopic undercuts
2) 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 enhance
wetting  contact angle good bonding
Demineralized porous enamel rod end (5-50Mm )
The resin can penetrate and produce
mechanical 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 viscosity
used for the adhesion to enamel or dentin.
 Acid etching + fluid resin bonding agent
the basis for the
1) Retention
2) 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 to
produce a surface that is more retentive.
 Dentin bonding system consists of:
1. Conditioning agent - to remove a
smear 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 dentin or
etched enamel

13.  Acid Etching _ Remove 10Mm of enamel
surface
 Conditioner _ Remove smear layer
 Primer _ Stabilize collagen and facilitate
penetration of bonding resin

14. Factors Affecting the Adhesive Bond
 Water.
 Saliva.
 Inadequate removal of acid etching.

15. Restorative Procedures:
 Shade selection
 Cavity preparation
 Etching liquid - for larger area sec.
Gel
• brush , syringe
• untouched 15 sec
• rinse 20 sec
• dry 5 sec

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 matrix
III, 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 excess
6) Finishing strip (medium and fine)
for
• final contouring
• finishing of proximal surface
Should 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.

27. THANK
YOU