The Importance of Finishing and Polishing Dental Restorations
Over the past decade, the entire field of dentistry has been migrating away from metal fillings and moving toward ceramics, composites or hybrid ceramic-composites. With the spread of CAD/CAM dentistry, we also are seeing procedures once primarily done in a lab setting completed right in the dental office. Dentists are now creating both direct and indirect dental restorations, and in many ways the dentist’s role as a clinician has expanded to include some of the duties of the dental technician.
But fabricating an anatomical, esthetic and functional dental prosthesis is only one part of this process, and your techniques for finishing and polishing these restorations are more important than ever. The key here is to not rush past these important steps. A smoother filling will result in a happier patient. Plus, a properly polished restoration will be less likely to build up stain over time.
Surface Coated: The most classic option for finishing and polishing is the “sand paper” style, similar to the classic Moore’s discs. Moving past paper, these can be attached to more sturdy materials such as plastics or metals to extend the life of the abrasive. These systems can be limited by the eventual loss of the abrasive from the surface of the material which can decrease their effectiveness.
Impregnated Materials: Brushes, cones, and points can all be impregnated with abrasives to allow for various levels of polishing. These tend to be useful for the final steps of polishing rather than coarse adjustments. Similar to stones, these materials usually have the abrasives throughout the material.
Stones: The best benefit to using a stone material to polish dental restorations is the grit is constant throughout its life of polishing. Many stones also come impregnated with materials such as silicon carbide to help get the job done. These can be used on metals, composites and porcelains.
Carbide Options: Burs transition from coarse to fine by increasing the number of flutes on the bur. Consider the shape of the bur to adapt to the largest possible area to avoid cross strokes on the material.
Diamond Burs: Similar to increasing the flutes of a carbide bur, these polishers go from coarse diamonds to increasingly fine surface coatings. These are especially useful for initial shaping and coarse adjustments to your restoration.
Shapes: All of the previously noted finishing and polishing instrument types are available in a range of shapes, from points, to cups, to discs, wheels and more. Consider the type and location of procedure you are doing. For example, is this an incisal repair, a lingual composite, or a posterior occlusal filling? Choose the shape that will fit and adapt completely to the surface you are polishing. Some systems use various brush shapes which may be more universally adaptable so you don’t have to switch as often.
Polishing Pastes: To achieve a final high gloss finish, polishing pastes make a great impact. They are mixed with abrasives such as diamond particles, and can be used with cups or brushes.
Keys to Success:
While this might sound obvious, it is incredibly important to understand the correct sequence to use when going from coarse to fine. It may be appropriate at times to jump in mid-sequence depending on how much finishing and polishing is required. There also are single-step polishing systems designed to do the job with just one polisher.
The main thing to avoid is creating a gloss finish over a bumpy surface. Because of this, it also is important to understand the material you are working on, and what works best in those situations.
If you are ever unsure about how to finish a particular material, there is perhaps no better resource than your lab technician. Schedule a time to head over there for a short tutorial. There is a reason why the restorations always look so fantastic when they come from the lab.
Questions to Ask
What types of finishing and polishing systems do I need for the materials I prefer to use?
How many shapes are available?
How many grits are available?
Will I need a paste for finishing the polishing?
How long can each instrument be expected to last?
Does the system work with multiple types of materials?