Evaluation of bonding performance and multi-ion release of S-PRG fillercontaining self-adhesive resin composite.

The bonding performance of a surface pre-reacted glass ionomer (S-PRG) filler-containing self-adhesive flowable resin composites to enamel and dentin were evaluated using a tensile bond test with thermal cycling. Also, the quantities of various ions released from the materials were measured using ICP atomic emission spectrometry and a fluoride ion electrode. The initial bond strengths of the materials were approximately 6 MPa, and decreased after thermal cycling. The S-PRG filler-containing self-adhesive flowable resin composites materials exhibited much higher ion release compared with the commercial self-adhesive flowable resin composite possibly due to different acidic monomers contained. It was suggested that the S-PRG filler containing self-adhesive flowable resin composites should be limited as a lining material or to restore small cavities in non-stress bearing areas.

Use of new scratch test and tensile test for evaluation of bond strength of selfadhesive flowable resin composite for repair of artificial tooth erosion.

The purpose of this study was to use a new scratch test and tensile test to evaluate the bond strength between artificial erosive enamel or dentin and self-adhesive resin composites as a coating material. Coronal enamel or dentin surface was exposed to an erosive cycle (artificial saliva [AS], pH:7.0 for 6.5 h and acidic carbonated beverages for 5 min, alternated 3 times per day) for the eroded-surface or stored in AS for the remineralized-surface. Two self-adhesive flowable resin composites, Fusio and LLB-CR6 (prototype), and a conventional flowable resin composite, BEAUTIFIL FLOW with self-etching primer system, Clearfil Mega Bond, were applied to enamel or dentin surfaces; and then the bond strengths were measured. For the eroded-surface, there were no significant differences in bonding strength among all materials, as assessed by the new scratch test. Thus, these self-adhesive flowable resin composites might be useful for coating materials on acid-eroded tooth surfaces.

Antibacterial activity of composite resin with glass-ionomer filler particles.

The purpose of this study was to examine the antibacterial activity of composite resin with glass-ionomer filler particles versus that of contemporary commercial composite resins. Three composite resins were used: Beautifil II (containing S-PRG filler), Clearfil AP-X, and Filtek Z250. Resin blocks were bonded to maxillary first molars, and plaque accumulation on the resin block surface was examined after 8 hours. For the antibacterial test, the number of Streptococcus mutans in contact with the composite resin blocks after incubation for 12 hours was determined, and adherence of radiolabeled bacteria was evaluated. Less dental plaque was formed on Beautifil II resin block as compared to the other two materials. Antibacterial test revealed that there were no significant differences in the number of Streptococcus mutans among the three composite resins. However, the adherence of radiolabeled bacteria to the saliva-treated resin surface was significantly (p<0.01) lower in Beautifil II than in the other two materials. These results suggested that Beautifil II could reduce dental plaque formation and bacterial adherence, leading to prevention of secondary caries.

Influence of different self-etching primers on the bond strength of orthodontic lingual buttons.

The aim of this study was to evaluate the influence of six self-etching primers (SEPs) on the shear/peel bond strength (SPBS) of orthodontic lingual buttons. A total of 150 extracted human premolars were randomly divided into six equal groups. In all groups, the lingual buttons were bonded with BeautyOrtho Bond and the enamel was conditioned with the following-group I (Control): Primers A & B; group II: Transbond Plus SEP; group III: Clearfil Mega Bond FA™; group IV: AdheSE; group V: Peak SE & Peak LC Bond; and group VI: Bond Force. The teeth were stored at 37°C for 24 hours and the SPBS was tested (0.5 mm/minute). The results were calculated in mega pascals (MPa) and statistically analysed [mean, standard deviation, Scheffè, analysis of variance (P < 0.05)]. The adhesive remnant index (ARI) was also evaluated and statistically analysed with a chi-square test. All groups demonstrated higher SPBS than the force suggested as necessary to accomplish orthodontic tooth movement, except group IV (7.7 ± 1.7 MPa), which showed a significantly lower value than groups I (10.7 ± 2.4 MPa), II (11.3 ± 3.1 MPa), and V (10.9 ± 2.8 MPa). The values of groups III (9.9 ± 1.6 MPa) and VI (10.5 ± 1.6 MPa) were comparable with those of groups I and V. Significant differences (P < 0.05) were found among the groups in ARI scores. The SPBS values of all groups could be clinically acceptable and lingual buttons might be successfully bonded with any of these SEPs except AdheSE since that conditioner significantly influenced bond strength. As the SPBS was lower in all groups than the value at which enamel fractures have been found, a sound enamel surface might be left after removal of lingual buttons.

Artificial plaque removal from interproximal tooth surfaces (maxillary premolar and molar) of a jaw model.

PURPOSE: The aim of this study was to compare the ability of the bristles of newly developed toothbrushes in removing artificial plaque deposits from the interproximal areas of a jaw model. MATERIALS AND METHODS: Four toothbrushes were evaluated in this study: A, two differences in level patterns, combination of flat and extremely high-tapered filaments; B, one difference in level pattern, combination of flat and extremely high-tapered filaments; C, rippled pattern and high-tapered filaments; and D, rippled pattern and tapered filaments. The brushing simulator was adjusted to provide a horizontal brushing stroke of 20 mm at a rate of 190 strokes per minute for a duration of 1 min. A 200-g force was applied to the brush head. A plaque-like substrate was placed in the facial and the interproximal sides of the artificial teeth that had the cross-sectional dimensions of mesial face in the maxillary right first molar and distal face in the second premolar. The results were photographed, and the area of penetration and the cleaning effectiveness were calculated for each picture by computer digital image analysis. This test was repeated five times for the toothbrush for each design that was evaluated. The resulting data were analysed using ANOVA and the Scheffe test. RESULTS: The rate of plaque removal was the highest with toothbrush A that gave a significantly greater removal of the artificial plaque than the other three toothbrushes on the maxillary right first molar mesial surface (P < 0.05). CONCLUSION: These results suggest that toothbrush A was more effective in plaque removal in this in vitro model used for determining the interproximal penetration of the four bristle designs.