No abstract

One-step polishing systems may be successfully used for polishing nanocomposites.

Aims:The aims of this study were to evaluate the effect of various finishing and polishing procedures on the surface roughness of six different composite resin materials (Artemis Enamel, TPH Spectrum, Filtek A-110, Filtek Supreme Enamel, Solitaire 2, and Filtek P-60) as well as to evaluate the effectiveness of the surface sealant application (BisCover) on the surface roughness after finishing and polishing procedures of tested composites.Methods and Materials: Specimens (n=168) measuring 5 mm in diameter x 2 mm in thickness were fabricated in a plexiglass well covered with a Mylar strip using six composite resins. A control group of seven specimens of each material received no polishing after being cured under the Mylar strip. Twenty-one specimens for each composite were randomly divided among three finishing and polishing groups (n=7). Each group was polished using a different system: Carbide bur/Sof-Lex disc, Carbide bur/Enhance disc with polishing paste, and Carbide bur/Edenta composite finishing kit. The average surface roughness (Ra, µm) of the control and treated specimens were measured with the Mitutoyo Surftest-402 Surface Roughness tester. After a surface sealant (BisCover) was applied to all treated specimens, according to manufacturer's instructions, the average roughness (Ra) was measured again. Results were statistically analyzed using analysis of variance (ANOVA) and the post-hoc Scheffe's test at a p<0.05 significance level.Results: Significant differences were found for the surface roughness (p<0.05) with interaction among composite resins and the finishing systems used (p<0.05). Enhance/Biscover finishing and polishing procedure surface was not significantly different from the Mylar strip surface groups (p>0.05). The Mylar strip group was not significantly different from the Sof-Lex/BisCover and Edenta/BisCover groups. Abstract © Seer PublishingThe ranking of mean Ra values by materials was as follows: Filtek Supreme Enamel < Filtek A110 < TPH Spectrum < Artemis

The aims of this study were firstly to investigate the fluoride-releasing characteristics of two composite resins (Tetric and Valux Plus), two polyacid-modified resin composites (Compoglass and Dyract), and conventional glass-ionomer cement (Ceramfil beta). The second aim was to assess the fluoride uptake and subsequent release from the same range of materials. Fifteen discs (6 mm diameter and 1.5 mm height) were prepared for each material. Each disc was immersed in 4 ML of deionized water within a plastic vial. The release of fluoride was measured daily at 1, 2, 3, 4, 5, 15, 30 and 60 days. After daily fluoride release was measured for 60 days, samples were refluoridated in 1000-ppm sodium fluoride (NaF) solutions (pH 6.6) for 10 min and fluoride release was measured daily for a total of 5 days. The release of fluoride from aesthetic restorative materials was measured by using specific fluoride electrode and an ionanalyser. Results were statistically analysed by two-way repeated measure ANOVA and Duncan's multiple range test. The results revealed that all fluoride-containing materials (Ceramfil beta, Compoglass, Dyract, Tetric) released fluoride initially and the release was greatest at the first day. At any time during the test period Ceramfil beta released the most and Valux Plus did not release any detectable fluoride (P < 0.01). Sample exposures to 1000 ppm NaF solution increased the 24-h fluoride release from all fluoride-containing materials. This difference lasted only 24-48 h after exposure. Ceramfil beta had a tendency to recharge not seen with the other materials (P < 0.05).