To the uninformed, the process of finishing and polishing dental restorations may seem purely cosmetic — even trivial. But clinicians know these steps are crucial to the restorative process.
Finishing Dental Restorations
No matter how well the color of a composite restoration matches the rest of a patient’s dentition, or how translucent and lifelike it looks, if the restoration is not finished correctly it will never look or wear right. Through the process of finishing, excess material on direct restorations is removed, margins are refined, anatomical contours and details defined and correct occlusion ensured. For this, an assortment of instruments comes in handy.
Carbide finishing burs and an array of bonded abrasive stones are included in the finishing lineup. Mounted on stainless steel shanks that can be snapped into rotary handpieces and glittering like sugared gumdrops in their holders, “stones” are, in reality, resin, silicone, glass/ceramic or elastomeric shapes ranging from discs, wheels, cups, and cones, to footballs, flames, and points onto which particles of grit have been bonded.
Grits are typically offered from coarse to superfine. The most typical materials used as grits are aluminum oxide, silicon carbide and diamond. There are also coated abrasives integrated onto flexible discs or strips, as well as unbonded abrasives that can be used in paste form. 1Fabris J, Stone R. All shapes and sizes. Mentor.2016;7(07):26–28,30. 2Stone R. Smooth Operator. Mentor.2013;4(4): 34–37.
The various shapes and sizes of these instruments are designed to help clinicians address different tooth surfaces. For instance, points may be helpful in reaching into occlusal pits and fissures, while interproximal finishing instruments are preferred for minor adjustments in cuspal areas. Such instruments will lend a more natural-looking convex contour, than would those with more elliptical or ovoid shapes, which could create a concavity — not the look most clinicians are going for. 3Loew R. CE Sponsored by Shofu–Clinical update on composite restoratives. Decisions in Dentistry.2017;3(7):37–42.
Polishing Dental Restorations
Once a direct restoration has been finished to the point that it looks like a real tooth, it must be polished to create surface luster. The same is true of indirect restorations. While finishing and polishing are usually thought of in conjunction with direct restorations, in some instances, a clinician will need to polish an indirect prosthesis, Typically finished and glazed in the lab, ceramic prostheses must often be adjusted chairside to ensure correct occlusion. This process takes off the glaze. The surface must then be polished — along with the rest of the restoration as, even after glazing, the surface may still be microscopically rough, which makes it more prone to staining. 4Stone R. Smooth Operator. Mentor.2013;4(4): 34–37. 5Vichi A, Fonzar RF, Goracci C, et al. Effect of finishing and polishing on roughness and gloss of lithium disilicate and lithium silicate zirconia reinforced glass Ceramic for CAD/CAM systems. Oper Dent.2018;43:90–100.
Polishing instruments include felt or synthetic buffers, rubber abrasives and polishing brushes, which excel at reaching the grooves in occlusal surfaces. 6Vichi A, Fonzar RF, Goracci C, et al. Effect of finishing and polishing on roughness and gloss of lithium disilicate and lithium silicate zirconia reinforced glass Ceramic for CAD/CAM systems. Oper Dent.2018;43:90–100.
But many are really just more finely gritted iterations of finishing instruments. Starting with the coarsest polishing instrument and working successively through grit sizes to a superfine grit is recommended. Surfaces, often with the help of a polishing compound or paste, are buffed until they shine and no marks or scratches are detectable. 7Stone R. Smooth Operator. Mentor.2013;4(4): 34–37.
In addition to promoting esthetics, polishing also promotes oral health. That’s because glossy surfaces are a poor substrate for bacterial growth. In addition, polished restorative materials are less abrasive, less likely to stain, and kinder to opposing dentition, especially in the case of zirconia and lithium disilicate restorations. 8Stone R. Smooth Operator. Mentor.2013;4(4): 34–37. 9Barnes CM. Polishing esthetic materials. Mentor.2013, 4(2): 20–23.
Lucky for clinicians, manufacturers will typically offer entire kits dedicated to finishing and polishing. One of the only challenges remaining is isolation.
For practitioners who would rather not compromise that esthetic direct restoration through moisture contamination, systems such as Isolite or Isody can work wonders. By not only protecting patients from inhaling or ingesting dental work byproducts, but also lending clinicians a helping hand through added illumination, retraction, and continuous evacuation, such integrated systems help ensure that whatever kind of restoration is placed, it will be a successful one.