Faculty Bibliography

BACKGROUND:There exists limited data in the literature regarding the efficacy and safety of consumer-available, paint-on bleaching solutions. PURPOSE/OBJECTIVE:The purpose of this in vitro study was to evaluate the effect of two consumer-available, paint-on bleaching products on enamel microhardness against a control and a dentist-prescribed, home-applied (DPHA) bleaching product. MATERIALS AND METHODS/METHODS:Eighty enamel slabs were obtained from extracted human teeth and randomly divided into four treatment groups: (1) control; (2) Opalescence (Ultradent Products, Inc., South Jordan, UT, USA); (3) Crest Night Effects (Procter & Gamble, Cincinnati, OH, USA); and (4) Colgate Simply White Night (Colgate-Palmolive Co., Piscataway, NJ, USA). Opalescence is a carbamide peroxide DPHA product, whereas Crest Night Effects and Colgate Simply White Night are consumer-available products. The specimens in groups 2 to 4 underwent 2 weeks of treatment for 8 h/d. Specimens were maintained in artificial saliva at 37 degrees C between treatments. Subsequently, one-half of the specimens in groups 2 to 4 (n=10) underwent an additional seven treatments for 8 h/d, while the other half were stored in artificial saliva, receiving no further treatment. Microhardness was measured as Knoop hardness numbers (KHNs) at baseline and after 1, 7, 14, and 21 treatment days. The results were analyzed for statistical significance both intra- and intergroups using analysis of variance (p=.05). RESULTS:A statistically significant reduction in mean KHN was observed compared with baseline at 1, 7, 14, and 21 treatment days for group 4 and at 7 treatment days for group 3. When compared with the control or DPHA product, group 4 was the only treatment that resulted in significantly lower mean KHNs at 7, 14, and 21 treatment days. CONCLUSION/CONCLUSIONS:When evaluating enamel microhardness, consumer available, paint-on bleaching solutions may adversely affect enamel microhardness compared to a control and 10% carbamide peroxide DPHA bleaching solution. CLINICAL SIGNIFICANCE/CONCLUSIONS:With numerous consumer-available bleaching products on the market, it is crucial to be judicious in their selection and use. The results of this in vitro study showed that the consumer-available, paint-on bleaching solutions adversely affected enamel microhardness at some time during the study. Consumers should be made aware of this effect on enamel.

UNLABELLED:Reproducing the form, function, and optical characteristics of natural dental structures with direct composites in large and moderately large proximoincisal (Class IV) restorations represents a great challenge for clinicians in general. Understanding color is fundamental to achieving success when restoring these defects, as was discussed in Part I of this two-part article (Volume, 16, Number 6). The proper restoration of the functional lingual contour is also a challenge that cannot be overcome without close attention to the restorative technique. In this second article, the composite application technique is discussed and presented in detail. Clinical photographs illustrate the proposed technique. CLINICAL SIGNIFICANCE/CONCLUSIONS:The proposed clinical protocol, including a try-in of the shades in a mock-up restoration to more accurately define color and shape, and a silicone guide to transfer the lingual and proximoincisal contour of the mock-up to the final restoration, is of great help to successfully restore proximoincisal defects.