anterior composite restoration

anterior composite restoration in dentistry

1. Anterior Composite Restorations Basil Jose St.Gregorios dental college

2. CONTENTS INTRODUCTION TO COMPOSITES INDICATIONS. CONTRAINDICAIONS. ADVANTAGES. DISADVANTAGES. CLINICAL TECHNIQUES FOR COMPOSITE RESTORATIONS. ANTERIOR COMPOSITE RESIN RESTORATIONS: CLASS III CAVITY PREPARATION FOR COMPOSITE RESINS.

3. CLASS IV CAVITY PREPARATION FOR COMPOSITE RESINS. CLASS V CAVITY PREPARATION FOR COMPOSITE RESINS. RESTORATIVE TECHNIQUES. CONCLUSIONS.

4. INTRODUCTION TO COMPOSITES DEFINITION: It is solid formed from two or more distinct phases that have been combined to produce properties superior to or intermediate to those of the individual components.

5. CLASSIFICATION OF DENTAL COMPOSITES 1)Based on filler particle type Homogeneous composites Macrofill- Macro fillers in the range of 10-100um. Midifill- Midfillers from 1-10um Minifill – Minifillers from 0.1-1um Microfill –Microfillers from 0.01-0.1 Nanofill- Nanofillers from 0.001-0.01um Megafill- Very large individual fillers particles, called megafillers. Heterogeneous composites Hetero-Midfill Hetero-Minifill Hetero-Microfill Hybrid composites Midi-Micro Hybrid Mini-Micro hybrid Mini-Nano Hybrid

6. Based on matrix composition BIS-GMA based composites. UDMA based composites Based on polymerization method Light cured composites Chemical cure composites Dual cure composites Based on viscosity Packable composites Flowable composites

7. COMPOSITION OF COMPOSITE RESINS THE BASIC COMPONENTS OF COMPOSITE RESINS INCLUDE THE FOLLOWING: RESIN MATRIX. FILLERS. COUPLING AGENTS. ACTIVATOR-INITIATOR SYSTEMS. INHIBITORS. OPTICAL MODIFIERS/ COLORING AGENTS.

8. RESIN MATRIX It is the continuous phase to which the other ingredients are incorporated. Most composite resins contain the following resin matrices: BisGMA (bisphenol A glycidyl methacrylate). UDMA (urethane dimethacrylate ) Combination of bisgma and UDMA.

9. FILLERS Fillers in composite resins are usually a type of glass such as quartz, silica, barium glass etc. The types of fillers used include quartz, silica, borosilicate glass, barium, strontium, zinc, zirconium . The filler content in composite resins ranges from 30%-70% or 50%-85% by weight.

10. COUPLING AGENTS The coupling agent binds the filler particles to the resin matrix and allow more flexible resin matrix to transfer stresses to the stiffer filler particles. Oraganic silanes like gamma-methacryloxy propyl trimethoxy silane is commonly used.

11. ACTIVATOR-INITIATOR SYSTEMS Composite resins polymerize by an addition polymerization mechanism that is brought about by the release of free radicals. Free radicals are released by: Chemical activation. Light activation: UV light. Visible light.

12. INHIBITORS These are added to prevent spontaneous polymerization of the monomers by inhibiting the free radical. Butylated hydroxy toluene 0.01% is added as inhibitor in composite resins.

13. OPTIMAL MODIFIERS/COLORING AGENTS Metal oxides in minute amounts are added to the composite resin to produce different shades of composites. Aluminium oxides and titanium oxide in small amounts provide opacity to composite resins. Darker shades and greater opacities have a lesser depth of curing than lighter shades.

14. POLYMERIZATION OF COMPOSITE RESINS High intensity quartz-tungsten-halogen (QTH) lights. Plasma arc curing (PAC) lights. Light emitting diode (LED) lights. Argon laser curing lights.

15. PROPERTIES OF COMPOSITE RESINS Polymerization shrinkage. Mechanical properties Linear coefficient of thermal expansion. Wear Water sorption. Solubility. Marginal integrity. Radiopacity. Esthetics, color, and color stability. Biocompatibility.

16. INDICATIONS Class I and class II cavities. Class III, class IV and class V cavities. Class VI cavities. Foundations or core buildups. Esthetic enhancement procedures. Luting cements. Interim restorations. Miscellaneous applications .

17. CONTRAINDICATIONS High caries incidence and poor oral hygiene. Heavy, abnormal occlusal stresses. Access and isolation difficulties. Subgingival extensions. Limited operator skill and knowledge .

18. ADVANTAGES Esthetics Conserve tooth structure. Adhesion. Low thermal conductivity. Universal application. Command set. Repairable. Can be polished at the same appointment.

19. DISADVANTAGES Polymerization shrinkage. Technique sensitivity. Time-consuming and expensive. Difficult to finish and polish. Increased coefficient of thermal expansion.

20. CLINICAL TECHNIQUES FOR COMPOSITE RESTORATIONS PRELIMINARY STEPS: Local anesthesia. Oral prophylaxis. Shade selection. Isolation. Check occlusal contacts.

21. SHADE SELECTION GUIDELINES FOR SHADE SELECTION The shade must be selected before drying the teeth because drying makes the teeth lighter in shade due to loss of translucency. Use shade guides for shade selection. Use good lighting, either natural or artifical during shade selection. For complex situation use a combination of shades. The shade selection should be made quickly within 30sec.

22. GENERAL CONCEPTS FOR CAVITY PREPARATION FOR COMPOSITES Minimal extensions. Pulpal and or axial walls of varying depth. Enamel bevel. Butt joint on root surfaces. Tooth preparation walls must be rough.

23. ANTERIOR COMPOSITE RESIN RESTORATIONS CLASS III CAVITY PREPARATION FOR COMPOSITE RESINS: CLASS III RESTORATIONS ARE DONE ON PROXIMAL SURFACES OF ANTERIOR TOOTH WHICH DO NOT INVOLVE THE INCISAL ANGLES.

24. CLASS III TOOTH PREPARATION There is a choice between facial or lingual entry into the tooth. INDICATIONS FOR LINGUAL APPROACH : To conserve facial enamel for enhanced esthetics. Carious lesions is positioned lingually. Lesion is accessible from the lingual.

25. Indications for facial approach: The carious lesion is positioned facially. Teeth is irregularly aligned, making lingual access undesirable. Extensive caries extent into the facial surfaces. Faulty restoration that was originally placed at the facial.

26. CLINICAL STEPS IN A CLASS III CAVITY PREPARTION: INITIAL CLINICAL PROCEDURE. TOOTH PREPARATION. LINGUAL VS FACIAL APPROACH. OUTLINE FORM. INITIAL TOOTH PREPARATION. FINAL TOOTH PREPARATION. RESTORATIVE TECHNIQUE MATRIX APPLICATION. PLACEMENT OF ADHESIVE. INSERTION AND LIGHT ACTIVATION OF THE COMPOSITE. CONTOURING AND POLISHING OF THE COMPOSITE.

27. TOOTH PREPARATION TOOTH PREPARATION FOR CLASS III DIRECT COMPOSITE RESTORATION INVOLVES: Obtaining access to the defect (caries, fracture). Removing faulty structures (caries, defective dentin, defective restoration). Creating convenience form for the restoration. DEPENDING UPON THE EXTENT OF THE PREPARATION TO BE THE RESTORED, THERE ARE THREE DESIGNS: Conventional. Beveled conventional. Modified.

28. BEGINNING CLASS III TOOTH PREPARATION(LINGUAL):

29. RESTORATIVE TECHNIQUE Matrix application. Placement of adhesive. Insertion and light activation of the composite. Contouring and polishing of the composite.

30. CLASS V CAVITY PREPARATIONS FOR COMPOSITE RESINS: CLASS V RESTORATIONS ARE DONE ON THE GINGIVAL THIRD OF FACIAL AND LINGUAL SURFACES OF ALL TEETH.

31. TOOTH PREPARATION After the usual preliminary procedure, the initial tooth preparation is accomplished with a round diamond bur, eliminating the entire enamel surface lesions or defect. The completed preparation is made with etched enamel and primed dentin.

32. CLASS V PREPARATION FOR LARGE LESIONS EXTENDING INTO ROOT SURFACES :

33. RESTORATIVE TECHNIQUE Acid etching and placement of the adhesive. Insertion and light activation of the composite. Contouring and polishing of the composite.

34. CLASS IV CAVITY PREPARATION FOR COMPOSITE RESINS: CLASS IV CAVITY PREPARATIONS ARE DONE ON THE PROXIMAL SURFACES OF ANTERIOR TOOTH THAT INCLUDE THE INCISAL ANGLES.

35. TOOTH PREPARATIONS SMALL DEFECT: The treatment of the teeth with minor coronal fracture requires minimal preparation. If the fracture is confined to enamel, adequate retention attained by beveling the sharp cavosurface margins in the fractured area with a flamed shaped diamond instrument followed by bonding.

36. LARGE DEFECT: Using A round carbide bur or diamond instrument of appropriate size at high speed with air-water coolant, the outline form is prepared. All weakened enamel is removed and initial axial wall depth is established. The bevel is prepared at 45 degree angle to the external tooth surface with flame shaped diamond instrument. The width of the bevel should be 0.5 to 2mm.

37. RESTORATIVE TECHNIQUE Contouring and polishing the class iv composite is similar to the technique of class iii composite but usually more difficult. The primary differences are: The involvement of the incisal angle and edge of the tooth and extended facial surface in large class iv. Close assessment of the incisal edge length and thickness. The potential occlusal relationship may be greater and require more adjustment and refinement.

38. RESTORATIVE TECHNIQUES FOR ANTERIOR COMPOSITE RESTORATIONS

39. ACID ETCHING This is done using 37% phosphoric acid liquid or gel . The gel may be applied using a syringe applicator or brush. The etching time is 15sec for both enamel and dentin preparations. Following this it has to be thoroughly rinsed with A water spray for 5 to 15sec. When the preparation is only in enamel, the surface can be dried with clean dry air. The etched enamel will appear frosty white due to the removal of both prism cores and peripheries creating microscopic irregularities. When the preparation involves both enamel and dentin, the surface should be dried using cotton pellets. This is because acid etching of dentin removes the surface hydroxyapatite from the intertubular and peritubular dentin thus opening the tubules leaving an interconnected layers of collagen fibrils.

40. BONDING For the smear layer removing dentin bonding agents, the primer and adhesive are combined in one bottle thus simplifying the bonding process. The bonding agent is applied using a micro brush. The bonding agent penetrates the irregularities on enamel and bonds micromechanically by formation of resins tags. On dentin the bonding agent penetrates the collagen network and the dentinal tubules forms a hybrid layer consisting of a resin-dentin interdiffusion zone.

41. MATRIX PLACEMENT The matrix may be placed either before or after etching and bonding. It is better to place the matrix band first before etching and bonding as it has the following benefits: Good isolation of the prepared tooth to allow proper adhesion. It can help assess the soundness of gingival cavosurface margin during wedge placement. For class iii cavities, clear polyester strip matrices are used. For class iv cavities, clear polyester strip or thin clear plastic crown form may be used. No matrix is needed for class v cavities.

42. Two types of matrices are available - polyester matrix - metal matrix • various matrix retainer which can be used are - Tofflemire retainer - Compound supported metal matrix - Sectional matrix system- palodent contact

43. Various matrices used in anterior composite restorations are: Clear plastic matrix: Transparent plastic strips are employed as matrices for tooth-coloured restoration as they allow light to be transmitted during polymerization of composite resins. Window matrix: This is modification of the tofflemire matrix. It is used for class v amalgam restoration. Tin foil matrix: This is used for class V restoration for conventional GIC. Tin foil may be preshaped and cut according to the gingival third of the buccal and lingual surfaces of the teeth to be restored. Preformed transparent cervical matrix: They are commercially available in various contours for use in anterior and posterior teeth.

44. INSERTION OF COMPOSITE RESIN The composite resin is built incrementally using special hand instruments in 1-2mm thickness. The material is contoured before light curing. The cavity is filled and contouring using the matrix before final curing.

45. DIFFERENT DESIGNS OF INCREMENT PLACEMENT 1. Three increment design One flat increment at gingival & Occlusal wall & two oblique Increments both at proximal box Occlusal box. 1st increment thinner than 1.00mm. 2. Horizontal layering design Small increments placed horizontally One above the other, starting from Gingival wall to occlusal wall.

46. 3 . Oblique layering design Each increment is placed obliquely Starting from any sides & Curing Is done from all three sides. 4 . U-shaped layering design At base, both gingival & occlusal gingival, U-shaped increment is given

47. 5 . Vertical layering technique Increments are placed in vertical fashion starting from one wall and carried on to another wall and curing is done from behind the wall. 6. Layering technique In the proximal box and curing each increment by inserting the fiber-optic microtip into composite.

48. FINISHING AND POLISHING After filling the entire cavity, the matrix is removed and the restoration is finished and polished using finishing burs, stones and strips. They are of two types:- Natural abrasives Manufactured or synthesized abrasives

49. CONCLUSION Composite resins have provided clinicians with a wide range of restorative options. They satisfy almost all the requirements of an ideal restorative material. Their use has risen almost exponentially in the last two decades and have enabled dentists to implement preventive and minimally invasive techniques, a prospect previously desired but never truly attained. More importantly, patients can retain their teeth longer, with a more esthetic appearance, resulting in a healthier and self-confident population.

50. REFERENCES Sturdevant’s art and science of operative dentistry. Clinical operative dentistry – Ramya Raghu. Basic dental materials – John J Manappallil.