The nanofill (Supreme) and minifill (Esthet-X) composites presented a surface roughness comparable to a microfill (Durafill), independent of the polishing system used, and a gloss comparable to a microfill, when polished with a one-step system (Pogo). As compared with the multiple-step systems, the smoothest surfaces and the highest gloss values were achieved using the one-step system (Pogo) for all the evaluated composites.

ObjectiveThe present study evaluated the association between lactotransferrin (LTF) gene polymorphism (exon 2, A/G, Lys/Arg) and dental caries.Material and MethodsA convenience sample of 110 individuals, 12 years old, was divided into: group 1, 48 individuals without caries experience (DMFT=0), and group 2, 62 subjects with caries experience (DMFT≥1). DNA was obtained from a mouthwash with 3% glucose solution, followed by a scrapping of the oral mucosa. After DNA purification, polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP) was performed to access the study polymorphism. The LTF A/G (Lys/Arg) polymorphism had been previously reported as located in exon 1.ResultsAllele 1 of the study polymorphism was associated with low DMFT index and showed a protective effect against caries experience (OR=0.16, IC=0.030.76, p=0.01).ConclusionLactotransferrin A/G (exon 2, Lys/Arg) polymorphism was associated with susceptibility to dental caries in 12-year-old students.

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©Operative Dentistry, 2007, 32-6, 589-594 JB da Costa • RF Mazur Clinical RelevanceThe results of this study suggest that tooth bleaching may lead to a reduction in enamel microhardness. Nonetheless, the application of a high concentration fluoride post-bleaching treatment may increase enamel microhardness and may restore enamel hardness to a level similar to non-bleached enamel, if the bleaching formula contains fluoride, potassium or ACP. SUMMARYThis in vitro study evaluated the new formulas of bleaching products and the effect of subsequent applications of fluoride on the hardness of enamel during and after tooth bleaching. The crowns of 60 extracted intact human molars were sectioned longitudinally; the buccal part was embedded in acrylic resin, the occlusal part was ground flat, exposing enamel and dentin, and then polished. Baseline Knoop microhardness (KHN) of enamel was determined. The specimens were then randomly divided into six groups of 10 specimens, and each group was assigned to a specific 10% carbamide peroxide (CP) bleaching agent. A: Opalescence, B: Opalescence PF (3% potassium nitrate and 0.11% fluoride), C: Nite White Excel 3 (ACP), D: Opalescence + F (acidulated phosphate fluoride 1.23%), E: Opalescence PF + F, F: Nite White Excel 3 + F. The teeth were bleached for eight hours; after each procedure, the specimens were stored in artificial saliva at 37°C. Immediately after day 21 of bleaching, the specimens in groups D, E and F received fluoride 1.23% for five minutes. KHN tests were performed before (baseline=control), during (14, 21) and two weeks (35 days) after the bleaching procedure and were statistically compared using ANOVA/Tukey's t-test (α<0.05). The statistical analysis revealed no significant difference among the bleaching materials (p=0.123). A significant enamel KHN reduction (p<0.001) was observed for all bleaching materials, with no difference among them. Two weeks after bleaching, all the groups that received fluoride showed a significant increase in microhardness. For the new bleaching formulas, the enamel was restored to a value similar to baseline.

The purpose of this study was to evaluate the push-out strength of two different adhesive cements (total etch and self-adhesive) for glass fiber post (GFP) cementation using two different techniques (microbrush and elongation tip) of cement application. In addition, this study evaluated the effect of total-etch conditioning before the use of a self-adhesive cement. Sixty premolar specimens with a single root canal were selected, endodontically treated, and shaped for GFP cementation. The specimens were randomly placed into one of six groups according to the cement and technique used: RelyX ARC (ARC): ARC + microbrush, ARC + elongation tip; RelyX Unicem (RU): RU + microbrush, RU + elongation tip; or RelyX Unicem + 37% phosphoric acid (RUE): RUE + microbrush, RUE + elongation tip. Each specimen root was cut perpendicular to the vertical axis yielding six 1.0-mm-thick sections. Push-out strength test was performed, followed by statistical analysis using three-way analysis of variance and the Games-Howell test (p<0.05). Statistically significant differences between the groups were found (p< 0.05). The cervical third of the roots had the highest mean push-out strength values, while the apical third had the lowest mean values regardless of the technique used. The elongation technique produced higher mean push-out strength values compared to the microbrush technique. The self-etch adhesive cement had the highest mean push-out strength value in all thirds. The addition of a conditioning step before the self-etch adhesive cementation appears to be effective in enhancing push-out strength with GFPs.