With diamond-impregnated rubber instruments now standard for polishing both composite and porcelain, the need to use a paste is greatly diminished. This is especially true when polishing a restoration extraorally with a straight handpiece. However, polishing pastes may still raise the gloss of a restoration one notch higher than is possible with a rubber instrument. A paste also helps to clean the surface of the restoration of any rubber instrument polishing debris and will aid in retaining surface texture by imparting a gloss without the abrasion of a rubber instrument or disc.
Overuse of rubber cups and especially discs can remove facial anatomy and texture, resulting in an unnatural look to restorations. In addition, carrying the paste interproximally with floss may impart a polishing effect on the proximal surfaces without leaving abrasive residue or opening the contacts. These pastes are also useful for hygienists and expanded duty auxiliaries to repolish restorations at recalls.
While aluminum oxide is still the main abrasive in many composite polishes, the fine diamond particles that have been the mainstay in porcelain polishes are being reduced in size even more. This means some diamond pastes can polish a composite to a higher shine compared to aluminum oxide. However, diamond pastes tend to be much more expensive, which could limit their widespread usage on composite.
As a general rule, aluminum oxide pastes work better when placed directly on the tooth and then the polishing instrument is moistened with increasing amounts of water as polishing proceeds. On the other hand, diamond pastes typically are more effective dry. Once saliva gets on the tooth or polishing instrument, the effectiveness of a diamond paste can drop precipitously. Exceptions to these general rules are noted, when applicable, in the product commentaries.
Almost as important as the paste itself is the type of instrument that actually delivers the paste to the restoration. Here is a list of options. Just be aware that, everything else being equal, using a straight handpiece instead of a contra-angle will enhance the result.
Prophy Cup Webbed with a latch-type mandrel is superior to any type of prophy cup in a disposable prophy angle. However, rubber prophy cups typically will not maximize the efficacy of any of these polishes. Nevertheless, with their ability to flare along a gingival margin, they may be the only choice when polishing this area, especially subgingivally.
Discs With Felt-Like Surface Sold by several manufacturers, these discs are typically more effective than prophy cups, but are too thick to get into many embrasures and their shape limits their effectiveness at the gingival margin. In our intraoral polishing simulation, FlexiBuffs were superior to prophy cups with virtually all pastes. This applied to our test composite, Esthet•X HD as well as our test porcelain, which is a leucite-based, pressable ceramic.
Brushes Can be very effective. Available in several different shapes, such as cups, points, and wheels. While the wheels tend to be the most effective, especially on occlusal surfaces, they may not be able to access the gingival margins. Cups that have a ring of brush fibers around a hollow center work much better gingivally, although the fibers can injure the tissue if you are not careful. Points are the least effective and typically would not be used unless no other instrument could access a specific area.
Felt Wheels Usually the most effective of all, but typically too large for many intraoral applications and very difficult to clean and sterilize. In our extraoral polishing test, felt wheels in a straight handpiece produced the overall best shine.
We ranked the various pastes based on whether they were able to create a gloss similar to enamel. On both composite and porcelain, the pastes were used after smoothing with rubber polishers. Both materials were polished using an intraoral simulation, which included using latch-type instruments in a contra-angle handpiece. The results are listed in the commentary of each product under Effectiveness.
NOTE All the CHOICES for porcelain were able to polish it to a high shine with a felt wheel in a straight handpiece.