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Is it necessary to apply a higher acquired polish to a restoration which is smoother than its inherent polish?
It is important to properly contour a restoration and place an acquired polish slightly better than its inherent polish. Any further polishing steps would be of value if the restorative placed had a long surface-transition time. If the surface-transition time of a restorative is relatively short, additional finishing past the inherent polish could increase the surface damage of the restoration which in turn can increase wear and fracture rates. Therefore, the end result, by finishing a material with a short transition time past its inherent polish, could actually result in poor clinical performance.
I was told that I should use a special resin over all of my restorations to repair the surface damage caused by finishing. Is it true only one product works for this?
Damage from finishing varies enormously depending on the techniques used. Generally, adequate curing time (e.g. 60 seconds or more with 40 mw/mm2 with a 475 nm. blue light source) and a postcure time over 10 minutes will reduce surface damage so dramatically that it is difficult to detect with an electron microscope. It has not been fully established if any specific, commercially available, surface coating (e.g. Fortify from Bisco) provides any improvement over adding and re-curing an unfilled resin over the finished surface at a greater thickness.
A major difference between specific materials made for this purpose (e.g. Fortify from Bisco) are that they are relatively more fluid than many bonding agents and are less affected by air inhibition. This may result in greater polymerization on the surface when thin applications are applied.
Is the difference between the inherent polish of a microfill compared to a minifilled composite clinically significant?
For most restorations with minimal esthetic exposure no. However, anterior restorations in smokers, heavy coffee drinkers, and in patients who use lipstick the difference between these materials can be clinically significant. The difference becomes most noticeable on patients where the clinician is restoring the upper 6 or 8 teeth in an arch with a high lip line. Another consideration is restoration size, microfills do very well in small restorations where minifills perform clinically better in larger restorations in terms of chipping and breakage. A key indicator for the clinician should be the past clinical performance of previously placed materials. The clinician will notice that there are significant differences between patients.
Many clinicians prefer carbide burs rather than diamonds for composite finishing. Is the damage caused by carbide burs clinically significant?
For gross reduction within a 0.5 mm of the final surface contour, probably not but the way they are used could change that. During the final 0.5 mm reduction of the composite surface our clinical experience has shown noticeable differences. If a clinician does not like the use of micron diamonds they can be replaced during the final 0.5 of contouring with discs.
Do you recommend wet finishing of composites? Doesn’t dry finishing allow better visibility and a better finish?
There are many degrees of water that can be used in dentistry. They can vary from a heavy air-water spray to a gentle and occasional wetting of the surface by an assistant with a water syringe.
Wet finishing, generally, falls between these extremes since it serves a purpose other than water used during tooth preparation.
Generally, the mount of water used should be just enough to reduce any unnecessary friction or heat from developing. With a handpiece and a micron diamond a very gentle water spray will lavage debris from the surface and actually improve visibility. This benefits both the clinician as well as the restoration since surface damage is reduced. With the use of discs, a water soluble lubricant, or aluminum oxide polishing paste, reduce the rapid heating and cooling cycles which will increase chipping, especially with microfills used on thin bevels. The end result of wet finishing is mainly to reduce the trauma on the margins and restored surface. The amount used is of clinical preference. Regardless of the technique, visibility and control should never be sacrificed.
Should polishing pastes be used on microfills?
Generally not since they will usually dull the surface by removing the resin smear layer that gives microfills their high shine. However, new products are continually being introduced so I would ask the composite manufacturer what the current research has shown for that material.
Some manufacturers and clinicians claim that the newer hybrids can be polished as well as microfills. Is this true?
This depends on the polishing system used. Some polishing systems produce a similar surface smoothness on selected microfills and hybrids.
However, if the best microfill finishing techniques are used on a quality microfilled composite and the best macrofilled finishing techniques are used on a quality small particle or minifilled composite. Clinically, the microfill is the clear winner due to the ease in which a higher luster can be produced.
Should diamond burs be used on slow speed or high speed handpieces?
Excessive speed and its resulting heat can clog finishing instruments. Studies have shown that low speed is best. However, most clinicians will not bear how slowly this removes excess restorative. As an alterative we use a high speed diamond, with light touching at almost stall-out speeds. Another good alternative are intermediate speed handpieces. I use one when I want the tactile sense needed to place texture in some restorations.
Caulk’s Enhance System is said to replace the classic 4-disc polishing system. Is it as effective as those discs?
This Question involves clinical preferences as well as basic research. Our study groups place much more value on long term clinical performance than scientific studies when the end result, needs to be a clinical judgement.
If “effective” means faster then the answer is occasionally, depending on the contours involved. If “effective” means control of the surface the answer is no. We have had clinical experience with both and usually prefers a disc system since it allows for greater control over the restoration.
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