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SURFACE SHAPING, COMPOSITES

CONTOURING

AND

TEXTURING

ANTERIOR

INTRODUCTION Composite restoration is the most demanding procedure in dentistry. Anterior composite restoration is used to restore defects of tooth color, shape or position caused by developmental problems; acute or chronic trauma; or caries. There are numerous composite materials to select from and a wide variation of restorative defects, which can potentially occur including class 3,4,5 and veneering restorations. This makes understanding factors, which affect restoration success, difficult but essential to obtain long lasting health, function and esthetics Factors used to provide proper restoration of anterior teeth with composite includes 1. Smile Design 2. Color and Color Analysis 3. Tooth Color 4. Tooth Shape 5. Tooth Position 6. Esthetic Goals 7. Composite Selection 8. Tooth Preparation 9. Bonding Techniques 10. Composite Placement Techniques 11. Composite Sculpture 12. Composite Polishing The least understood and least completed of these is proper surface shaping, contouring and texturing. General shaping of embrasures, contacts, incisal edge and gingival outline establish the silhouette of a tooth while line angles and height of contour establish the face of a tooth. Controlling factors, which form the face and silhouette of a tooth, provide a perception of tooth size. Surface contours and texture further alter size perception by controlling light transmission, reflection, refraction and absorption Transmission of light is measured by translucency of a material, which defines how much light can pass through. Reflection is when light bounces off a surface. Refraction is when light enters a material but the direction of the light is bent at the surface of the material. Absorption is when light enters a material but does not leave Reflection and refraction of light is dependant on the angle at which light strikes the surface of a material. It is important to produce proper surface shape, contours and texture to control reflection and refraction and simulate natural teeth LIGHT CONTROL Controlling light is critical to color perception. When light enters enamel, it proceeds through the enamel and strikes dentin. Some light is absorbed and some reflected by dentin. Reflected light exits through enamel so the eye sees dentin color. There are several factors, which influence this color perception The first factor, which alters uniform color appearance, is enamel thickness and enamel make up. Enamel thickness lessens the amount of color, which shows through so gingival areas where enamel is thin shows more yellow. Enamel structure may include areas where improper enamel formation occurs as is seen with hypocalcification, fluorosis and


staining. Enamel construction can further be altered by aging as is seen by chipping and cracking The second factor which influences color perception is alteration of dentin color. Dentin substructure is not always one uniform color through out and can be seen through enamel as such The third factor is light direction and intensity. Light intensity determines how far light enters through enamel and reflects off dentin. Light direction determines if light is transmitted, reflected or refracted. At different angles different effects can occur and different angle relative to a small tangents to the surface vary tremendously if the surface is smooth or textured. Smooth areas produce large areas of transmission, reflection or refraction of enamel. Textured surfaces can produce hundreds of small areas of transmission, reflection or refraction of enamel and a much different effect Enamel is translucent and prismatic because of its enamel rod structure. Enamel also has varying surface contours and textures, which absorbs, reflects or refracts light. Composite does not have a prismatic effect but can be contoured and textured to mimic an enamel appearance with similar light absorption, reflection and refraction Surface contouring and texturing of a composite restoration is often done even if adjacent enamel is smooth to match enamel, which has the influence of enamel rods prismatic effect. It should be noted that often composite should be uniform in contour, non textured and smooth to blend to existing tooth structure, however, often this result is unsatisfactory

COMPOSITE SHAPING Composite shaping refers to generalized formation of the silhouette and face of a tooth, which includes embrasures, contacts, incisal edge, line angles, and gingival height of contour. It is ideal to shape a restoration to final contour, cover the composite with glycerin to avoid an oxygen inhibited layer and light cure. The reality is that very few dentists can accomplish this with composites, which prematurely thicken with ambient light, stick to instruments or do not display proper thixotropic qualities


Dentists most often overbuild restorations and reduce them to a proper dimension. Techniques vary for class 3, class 4 and class S restorations while veneers and surface restorations combine these techniques COMPOSITE CONTOURING Composite contouring refers to shaping larger composite details within the uniform contour of a tooth. Surface contouring provides details shaped flat, convex or concave. These details are usually placed after curing of composite. They are common in class four and veneering restorations. They are not as common in class three and five restoration. Light reflection on a smooth surface creates an uninterrupted white line

COMPOSITE SURFACE TEXTURING Surface texturing of composite is placement of numerous small areas of convexities and concavities on a restoration surface. A youthful natural tooth enamel surface is highly textured but as teeth age texture is lost resulting in a smooth surface. There are a variety of surface textures, which result from tooth formation and aging. Different techniques are used for placement of texture depending on the required results. Goals can be generalized as occurs with full veneering cases or defined by remaining tooth structure of the same tooth or adjacent teeth


SHAPING CLASS THREE AND FOUR RESTORATIONS Class three and four restorations require shaping and removal of excess composite on the facial, lingual and interproximal surfaces. Facial surfaces, which are convex, are shaped with sandpaper disks or polishing cups starting with coarse and proceeding to fine polishers. The progression from coarse to fine under wet conditions minimizes heat generation and negative affects which can occur from composite expansion. Lingual surfaces, which are convex and/or concave, can require sandpaper disks, polishing cups and points, and bedew wheels. If reduction of large amounts of excess composite is required, diamond or finishing burs are used. Care must be taken to avoid heavy pressure, which could provide sufficient trauma to separate composite material from tooth structure at the cavosurface area. The result is a white line resulting from a gap collecting polishing debris. It should be noted that a composite white line can also occur from material not being placed fully into position or being pulled away from tooth structure during instrumentation. The author prefers a flame shaped 12 fluted Midwest 7901 for general shaping. On lingual areas where a deeper concavity occurs, a fine football shaped diamond is used Inter proximal surfaces are initially shaped by slight curvature of a mylar strip prior to light curing. Final shaping is done with a 7901 flame shaped bur or sandpaper disks and inter proximal sand paper strips CLASS FIVE When large amounts of composite is to be removed for gross reduction, fine flame shaped diamond burs or 12 fluted 7901 burs are used. Further shaping is accomplished with coarse polishing cups. Final shaping is done with fine polishing cups or very soft webbed prophy cups COMPOSITE VENEERS Composite veneers are shaped as if they are combinations of class 3,4 and 5 restorations. There are many techniques, which can be used depending on personal preference. The author's preference includes, general shaping which is done with coarse sand paper disks. Forming of definitive line angles, embrasures and gingival height of contour is done with a 22 fluted 7901 finishing bur. Gingival areas are further shaped with gray and green polishing cups. Surface contouring is then done with medium and fine polishing sandpaper disks SURFACE CONTOURING and TEXTURING ANTERIOR RESTORATIONS There are many techniques, which produce similar and specialized results. Instrumentation and the techniques, which can be done with each, define expected results. Instrumentation to do composite surface contouring and texturing includes


sandpaper disks, burlew wheels, 7901 flame shaped 12 fluted finish bur, polishing points, polishing cups, diamond burs and finish burs SANDPAPER DISKS Sandpaper disks are used to form general contours by placing the flat sandpaper surface against a composite surface and changing the angle as it move across a convex surface. To form surface lines and concave areas into composite, as occurs with lines in mamelon areas, the edge of a sandpaper disk at approximately a 30 degree angle is moved gingival-incisally and then moved laterally with less pressure and less angle To form individual lines on a composite surface, a medium or fine sandpaper disk is held at a 45-degree angle and moved along the line. Less angulation forms a finer line or indentation. A generalized surface texturing, is accomplished by rapid movement back and forth at various locations Fine sandpaper disks at high revolution under water or polishing paste are used for a high gloss finish. Angling the disk allows a high gloss finish into even fine areas. Fine sandpaper disks remove very little composite so detail is rarely lost BURLEW WHEELS Burlew wheels are used to produce detail with a relatively high polish. Burlew wheels disintegrate quickly so generalized shaping or fine line formation is difficult. They are fine grit and remove small amounts of composite so heat generation can be high if large amounts of composite are removed Burlew wheels are ideal for placement of concave areas such as long indentations or spot round indentations. The shape of the burlew wheel is easily altered against green stones to form custom shape and size indentations in composite. Burlew wheels are further ideal for fine adjustment of lingual occlusion


7901 FINISHING BUR The 7901 finishing bur is an ideal instrument to do any type of shaping dependant of the dentist's ability to free hand shaped. The 7901 are flame shaped with convex external surfaces. The cutting convex surface always produces concave surfaces on composite when moved back and forth. More pressure and a deeper cut produces a larger concavity Circular concavities are produced by moving the 7901 in a circular movement. The size of the resulting dimple is dependant on pressure and depth Lines are formed by moving the bur up and down along its long axis. The width of a resulting line is dependant on which part of the bur strikes the composite. If the end of the bur is used, a sharp line forms. If the middle of the bur is used, the line is more concave matching the diameter of the middle of the bur

POLISHING CUPS AND POINTS Grey polishing cups produce large convex surfaces and are ideal for general shaping. The side of a grey cup can be used for forming lines and some general anatomy Green polishing cups provide very high polish with little composite removal. They are used to place a high gloss after use of grey polishing cups. In addition, green cups are used for high polish of fine, highly texture surfaces. Turning the cup at a 45 degree angle, allows polishing into fine areas. Turning the drill at different angles further allows the green cup to enter all fine areas Polishing points work in the same way as cups. Polishing points, however, must be kept pointed to allow the diameter to be as small or smaller than composite concavities or polishing cannot occur DIAMOND BURS Diamond burs create a generalized rough textured surface when diamonds of medium, coarse or extra coarse grit are used. Fine and super fine diamonds produce little texturing effect but are used for some shaping. The author does not use diamonds often for shaping but does produce generalized surface texturing with them


A medium diamond creates a fine textured surface while a coarse diamonds creates larger, wider lines of texture. Texture is produced by running the diamond over the entire surface in a back and forth motion. Reduction of texture in areas or overall can be achieved with burlew wheels, medium sandpaper or coarse grey cups and points. To produce a high gloss after using diamonds, fine sandpaper disks or fine green polishing cups are used

FINISHING BURS Finish burs are used for final shaping and contouring. Finish burs have concave, convex or flat cutting surfaces so results vary depending on the bur. This means that each bur must be analyzed for shape to predict what various cutting motions will produce Finishing burs are important to get into fine areas such as embrasures and subgingival combined with manual gingival retraction RECOMMENDED MATERIALS COMPOSITE: POINT 4 BONDING AGENT: OPTIBOND SOLO PLUS CURING LIGHT: L.E. DEMETRON 1


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