Michael Miller, DDS
Are reservoirs really necessary for home bleaching trays? I have read in the 2000 edition of REALITY that your "own clinical study suggests reservoirs are not necessary and may even be contraindicated in some patients." Could you please elaborate on this?
We did a "split-mouth" study of 21 patients who bleached with a tray that had reservoirs on the right side, but no reservoirs on the left. Approximately one week after bleaching was ended, we evaluated the patients. The results showed no visible differences between the reservoir and nonreservoir sides. Therefore, we concluded that reservoirs do not increase the efficacy of home bleaches, including Nite White Excel 2, Opalescence PF, Zaris, Day White 2, Rembrandt Xtra Comfort, and Hi Lite 2.
Other reports are surfacing that agree with our results. One issue that still remains, however, is how quickly the bleaches degrade. It has been suggested that most bleaches work best during the first hour of treatment and should be replenished or discontinued at that point. The patients in our study bleached for short and long periods of time without any apparent differences.
I have been using Estenia for the past few months and am very happy with the esthetics and fit. What is its long-term outlook regarding wear? Can it be used for indirect onlays?
Estenia is a very interesting material. It is the hardest indirect resin we have ever tested by far and, by virtue of this hardness, the most ceramic-like. This may be an advantage or a disadvantage. If you want a harder, more ceramic-like finish, then you`ll very much appreciate Estenia. If you are using it as a replacement for a ceramic because it should be less abrasive and easier to adjust and polish like other indirect resin systems, then you may not like Estenia.
In a recent bonding study, we found the cementation of Estenia to dentin to be outstanding. This suggests that indirect onlays made of Estenia should perform quite well. Wear-resistance figures to be outstanding, although it`s still too early to tell. It has no high-strength core material, so you`ll need to go outside Kuraray for bridge reinforcement or you will need to use a metal substructure for bridges.
How does the Optilux 501 compare to other high-powered curing lights for speed, quality of curing, and bleaching ability?
As we reported in the 2000 edition of REALITY, we have not found any differences in microleakage when Class II and V restorations were cured with any of our tested lights, including the high-powered ones. Our preliminary bleaching study, using a number of lights and bleaches, failed to find any differences either.
Curing speed is another issue. The plasma arcs seem to be the fastest, but certainly not 1-3 seconds as mentioned by at least one manufacturer. Play it safe and cure for 10 seconds. Our preliminary bond- strength data for the 501 with the regular tip and the Turbo Tip for various curing times suggest no differences, so you could probably cure for 20 seconds instead of 40. We are continuing to conduct tests in this area, so the final answer on which type of light to buy is still pending. However, it`s hard to go wrong with the 501.
Dr. Miller is the publisher of REALITY and REALITY Now, the information source for esthetic dentistry. He is an international lecturer and a fellow of the American Academy of Cosmetic Dentistry, as well as a founding member. He maintains a private practice in Houston, Texas. For more information on REALITY and to receive a complimentary issue of his monthly update, REALITY Now, call (800) 544-4999 or visit www.reality=esthetics.com.
