A randomized controlled trial on the plaque-removing efficacy of a low-abrasive air-polishing system to improve oral health care.

OBJECTIVES: While air polishing with abrasive powders has been proved efficient for sub- and supragingival application, only few studies concerning the quality of supragingival biofilm removal using the low-abrasive erythritol powder (EP) exist. The aim of the present randomized controlled trial was to clinically compare the efficacy of supragingival air polishing using EP in comparison with the rubber cup method, and to juxtapose the corresponding biofilm regrowth rates. METHOD AND MATERIALS: Thirty-two young adults, suspending oral hygiene for 48 hours, were enrolled in the present double-blind short-term investigation. Using a split-mouth design, tooth polishing was conducted by means of either air polishing or rubber cups with prophylaxis paste (control). While 16 participants received air polishing in the second and fourth quadrants (and rubber cup prophylaxis in the first and third ones), the reverse sequence was applied with the remaining 16 subjects. Biofilms were assessed using the modified Quigley-Hein index (QHI), and QHI sum scores achieved both prior to and immediately after the polishing procedure, as well as 24 hours later, were assessed using a two-way analysis of variance (ANOVA), followed by Tukey's HSD to test multiple pairwise comparisons. RESULTS: Both methods revealed a significant reduction of QHI scores (P < .001). Compared to the rubber cup method, air polishing resulted in significantly lower scores, both after tooth cleaning and after 24 hours (P < .001). CONCLUSIONS: Supragingival biofilm removal by means of air polishing combined with low-abrasive erythritol seems to be more efficacious than the traditional polishing method, and should improve oral health care.

Bond strength of fiber posts after the application of erbium:yttrium-aluminum-garnet laser treatment and gaseous ozone to the root canal.

The aim of the present study was to investigate the effects of antibacterial agents (erbium:yttrium-aluminum-garnet [Er:YAG] laser or gaseous ozone) intended to disinfect root canals on bond strengths of fiber posts compared with canals that were finally irrigated using chlorhexidine (CHX). One hundred forty-four human anterior teeth were divided into three groups (n = 48); root canal instrumentation was performed, and antimicrobial pretreatment was conducted as follows: control group: CHX, group 2: Er:YAG laser, and group 3: gaseous ozone. In all groups, fiber posts were inserted using Panavia F 2.0 (Kuraray, Osaka, Japan), Variolink II (Ivoclar Vivadent, Schaan, Liechtenstein), RelyX Unicem (3M Espe; Seefeld, Germany), or Ketac Cem (3M Espe) (n = 12 each). Push-out bond strengths to root canal dentin were affected by the type of luting agent but not by the antimicrobial pretreatment regimen. However, significant interactions between the luting agent and pretreatment could be observed, and adhesion of the self-adhesive resin cement RelyX Unicem was significantly reduced after using gaseous ozone.

Effect of adhesive resin cements and post surface silanization on the bond strengths of adhesively inserted fiber posts.

This study evaluated the tensile bond strengths and the effect of silanization of fiber posts inserted with different adhesive systems. Sixty DT Light Posts (size 1) were used. Thirty posts were pretreated with silane. The posts were cemented into form-congruent artificial root canals (12 mm) of bovine dentine. Six groups were formed: G1, Prime&Bond NT/Calibra; G2, Monobond-S+Prime&Bond NT/Calibra; G3, ED Primer/Panavia 21ex; G4, Monobond-S+ED Primer/Panavia 21ex; G5, RelyX Unicem; and G6, Monobond-S+RelyX Unicem. The mean (standard deviation) tensile bond strengths (megapascals) were 7.69 (0.85) for G1, 7.15 (1.01) for G2, 6.73 (0.85) for G3, 6.78 (0.97) for G4, 4.79 (0.58) for G5, and 4.74 (0.88) for G6. G1 achieved significantly higher bond strengths than G3 and G5; G3 had significantly higher values than G5 (P < .05; Scheffé procedure). Silanization had no significant effect (P > .05, one-way analysis of variance). Tensile bond strengths were significantly influenced by the type of resin cement. Silanization of fiber post surfaces seems to have no clinical relevance.

Influence of adhesive systems on bond strength between fiber posts and composite resin cores in a pull-out test design.

The aim of this study was to evaluate the effects of post surface conditioning with adhesive systems on tensile bond strength between two composite resin core systems and FRP posts (ER DentinPost). Forty-eight posts were trimmed at the coronal part, and the upper part of 3 mm was covered with a standardized composite resin core build-up. Twenty-four posts were treated with the respective adhesive systems. Four groups were formed: G1 - ClearfilCore; G2 - Clearfil New Bond + ClearfilCore; G3 - MultiCore Flow; and G4 - AdheSE + MultiCore Flow. Mean (SD) bond strengths in MPa were 7.53 (0.89) for ClearfilCore and 8.08 (0.93) for New Bond + ClearfilCore; 5.80 (0.39) for MultiCore Flow and 5.92 (0.43) for AdheSE + MultiCore Flow. ClearfilCore achieved significantly higher bond strengths than MultiCore Flow (two-way ANOVA; p<0.0001). In conclusion, composite resin core materials exerted a significant influence on tensile bond strength, while adhesive systems did not significantly affect the results.

The influence of human plasma used for dentin perfusion on tensile bond strength of different light-curing materials.

PURPOSE: To evaluate the influence of two perfusion solutions, saline and human plasma, on tensile bond strengths of five different light-curing materials in an in vitro investigation. METHODS: 150 human third molars were used. All teeth were prepared in a special manner allowing the simulation of intrapulpal pressure and dentin perfusion. Dentin specimens with a thickness of 3.5 mm were obtained under standardized conditions. The specimens were randomly assigned to 10 experimental groups. Five groups were perfused with physiologic saline while with the other five with human plasma under constant hydrostatic pressure of 30 cm H2O was used for at least 1 hour. Tensile bond strength of the different dentin bonding agents and composite or compomer materials (A: Syntac/Tetric, B: Prime & Bond NT/Spectrum TPH, C: Solobond Plus/Arabesk, D: Compoglass SCA/Compoglass, E: Dyract PSA/Dyract) was evaluated using an Zwick Universal testing machine 10 minutes after light-curing. RESULTS: Pairwise comparison showed a significant increase of bond strengths in all human plasma perfused subgroups (P< 0.05; Wilcoxon). The influence of the different dentin adhesives was significant (P< 0.001; ANOVA). The significantly highest values were observed for the composite groups Syntac/Tetric and Solobond Plus/Arabesk (P< 0.05; closed test procedure). The compomer Group D (Compoglass SCA/Compoglass) showed significantly decreased values compared to all other groups (P< 0.05; closed test procedure). Within the limitations of an in vitro study, it can be concluded that the use of human plasma might result in higher tensile bond strength compared to saline.

Gene expression of human beta-defensins in healthy and inflamed human dental pulps.

Human beta-defensins (hBDs) are antimicrobial peptides that play an important role in the innate host defense against bacterial invasion, contribute to promotion of adaptive immune responses, and show chemotactic activities. The aim of this study was to compare the gene expression of hBD-1, -2, -3, and -4 in healthy teeth and teeth with pulpitis. Samples of healthy and inflamed dental pulps were obtained from extracted third molars and during treatment of teeth with pulpitis. Gene expression was assessed by using reverse transcriptase reaction and real-time polymerase chain reaction. HBD-2 and hBD -3 were only weakly expressed in healthy and inflamed pulps. In contrast, the expression of hBD-1 and hBD -4 was significantly increased in inflamed compared with healthy pulps. These results suggest that hBD-1 and hBD-4 might play a role in the pulpal host defense.