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The antibacterial activity, and the effect of the application of additional topical fluoride on the bacterial activity, biofilm formation, and surface roughness of new-generation hybrid/fluoride-releasing materials were investigated. Two hundred and forty specimens were prepared in split Teflon molds (8 × 2 mm) from a resin composite (as negative control: G-aenial A’Chord/GC), Equia Forte HT Fil(GC), Equia Forte HT Fil+Equia Forte Coat, Riva Self-Cure (SDI), Riva Self-Cure+Equia Forte Coat, Zirconomer (Shofu), Beautifil II (Shofu), and Riva Silver (Shofu). Penicillin G,1U was used as positive control. The antibacterial activity was evaluated by the agar diffusion test immediately after the materials set using Streptococcus mutans (S. mutans) and Lactobacillus casei (L. casei), and repeated after application of 0.20% w/w (900 ppm) topical fluoride. The biofilm formation of S. mutans on each material was quantified by crystal violet staining. Surface roughness of the specimens was measured by a profilometer. The data were analyzed by Kruskal–Wallis, Dunn’s, one-way ANOVA, and Tukey’s HSD tests (p < 0.05). None of the tested restorative materials showed antibacterial activity and no inhibition zones were observed after treatment of the restoratives with additional topical fluoride. There were significant differences among the groups in terms of biofilm formation (p < 0.005). Equia Forte HT Fil with and without coating showed the lowest, while Riva self-cure without coating and Zirconomer showed the highest biofilm accumulation. None of the new-generation hybrid/fluoride-releasing materials demonstrated antibacterial activity and additional topical fluoride application did not make any change. Biofilm formation of the tested materials differed. All tested materials showed different surface roughness values (p < 0.005). Characteristics and compositions of the materials seemed to be more effective than the surface roughness.

Aim. The aim of this study was to evaluate the presence of the cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in human periapical lesions. Subjects and methods. Samples were obtained from three groups of teeth: symptomatic teeth, asymptomatic lesions, and uninflamed periradicular tissues as a control. Results. TNF-alpha levels were significantly increased in symptomatic lesions compared to control. Group with asymptomatic lesions had significantly higher concentrations compared to control. There were no significant differences in TNF-alpha levels between symptomatic and asymptomatic lesions. In group with symptomatic lesions, IL-6 levels were significantly higher than in group with asymptomatic lesions. The IL-6 levels in symptomatic group also showed significantly higher concentration in comparison with control group. In asymptomatic group, the IL-6 level had significantly higher concentrations compared to control. Conclusion. These results indicate that symptomatic lesions represent an immunologically active stage of disease, and asymptomatic lesions are the point from which the process advances toward healing. [ABSTRACT FROM AUTHOR]

Prior research reveal that low-viscosity resin is able to significantly penetrate initial caries lesions, which leads to their stabilization. The objective of the present report is to assess the shear bond strength (SBS) of orthodontic brackets bonded with different adhesives to demineralized enamel treated with a low-viscosity resin infiltrant. It also aims to compare the achieved bond strengths to those achieved in relation to sound enamel (SE). A total of 48 newly extracted third molars were collected, distributed in four groups (n=12), covered with a nail varnish, with 4 x 4 mm of uncoated area, immersed in Buskes demineralizing solution (14 days, 37 °C) or remained untreated. Group I: SE + Transbond XT; Group II: demineralized enamel (DE) + ICON + Transbond XT; Group III: DE + ICON + Scotchbond Universal; Group IV: DE + ICON + Assure PLUS. SBS was quantified in megapascals (MPa) and statistically analyzed (ANOVA, p ≤ 0.05). The mode of failure was assessed microscopically (10 x magnification). The highest SBS detected was in Group IV, and the difference was statistically significant (F = 14.37; p = 0.000). Treatment with a resin infiltrant on DE does not impair the shear bond strength when compared to SE, although it does produce a significantly higher strength when combined with Assure PLUS.

The purpose of this in vitro study was to evaluate the microtensile bond strength of one-step self-etch adhesive to human dentin surface modified with air abrasion and sonic technique and to assess the morphological characteristics of the pretreated dentin surface. The occlusal enamel was removed to obtain a flat dentin surface for thirty-six human molar teeth. The teeth were randomly divided into three experimental groups (n = 12 per group), according to the pretreatment of the dentin: (1) control group, (2) air abrasion group, and (3) sonic preparation group. Microtensile bond strength test was performed on a universal testing machine. Two specimens from each experimental group were subjected to SEM examination. There was no statistically significant difference in bond strength between the three experimental groups (P > 0.05). Mean microtensile bond strength (MPa) values were 35.3 ± 12.8 for control group, 35.8 ± 13.5 for air abrasion group, and 37.7 ± 12.0 for sonic preparation group. The use of air abrasion and sonic preparation with one-step self-etch adhesive does not appear to enhance or impair microtensile bond strength in dentin.