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Background: The aim of this in vitro study was to compare the degree of microleakage on enamel and dentin margins of class V cavities prepared with either a high-speed drill or an Er,Cr:YSGG laser (2780 nm) and to associate their use with a beveling method for the margin.

Purpose: To evaluate the effect of three different fluoride treatments on the surface microhardness and morphology of human enamel exposed to two different bleaching agents.Materials and Methods: Twenty-three extracted human third molars were sectioned to obtain 90 enamel fragments, mounted on acrylic resin supports, polished and randomly divided into 9 groups (n = 10). The specimens were exposed to a combination of two bleaching agents (22% carbamide peroxide [CP] and 38% hydrogen peroxide [HP]) and three fluoride treatments (0.05% NaF daily, 0.2% NaF weekly and 5% NaF final topical fluoridation). The positive control group specimens were not exposed to bleaching agents or fluoride treatments. The negative control group specimens were exposed to the bleaching agents but none of the fluoride treatments. All specimens were stored in artificial saliva during the entire experiment, and enamel microhardness was evaluated. Surface microhardness data were statistically analysed using two-way ANOVA and Tukey's post-hoc test at a significance level of α = 0.05. Additionally, three specimens of each experimental group were examined under SEM.Results: Two-way ANOVA revealed significant differences between the experimental groups (p < 0.05). The bleached group specimens which did not receive fluoride treatment exhibited significantly lower microhardness than those treated with fluoride (p < 0.05). Varying degrees of surface changes were observed among the experimental groups.Conclusion: Both bleaching agents significantly reduced enamel microhardness and the topical fluoride treatments after bleaching significantly enhanced the surface microhardness of the enamel. The surface morphology of the enamel was altered after bleaching and fluoride treatments. [ABSTRACT FROM AUTHOR]

Purpose: To determine the ability of 5 contemporary fluoride-releasing restoratives and 3 fluoride-releasing adhesives to inhibit enamel demineralisation surrounding restorations, and the associations between inhibition and the levels of fluoride released from these materials.Materials and Methods: Five fluoride-releasing restoratives (Fuji IX GP, Ketac N100, Dyract Extra, Beautifil II and Wave) and 3 fluoride-releasing adhesives (Stae, Prime & Bond NT and Fluoro Bond II) were investigated. Eight disks of each material were prepared. Fluoride release was measured daily using a fluoride-ion-selective electrode for 15 days. Twenty-four cavities for each group were restored with a restorative and an adhesive. Specimens were subjected to thermal stress and stored for 30 days in saline solution. After a 15-day pH-cycling regimen, two 150-μm-thick sections were derived from each specimen. Enamel lesion depth was measured at 0, 100, and 200 μm from each restoration's margin via polarised light microscopy.Results: Of the restoratives investigated, Fuji IX GP released the most fluoride. The fluoride-releasing restoratives tested exhibited shallower enamel lesions than did the control group at all distances tested (p < 0.05). Fuji IX GP yielded significantly lower enamel lesion depth than did the other experimental materials. The depths of enamel lesions did not differ significantly when comparing restoratives applied with a fluoride-releasing adhesive with those applied with a non-fluoride-releasing adhesive.Conclusion: The fluoride-releasing materials tested reduced enamel demineralisation but to different extents, depending on their levels of fluoride release. Fluoride-releasing adhesives did not influence enamel lesion formation. [ABSTRACT FROM AUTHOR]

Aim The aim of the present study was to evaluate the effect of preheating and shade on the surface microhardness of silorane-based composites. Methods Three shades of two different types of composites were evaluated: a silorane-based composite and a methacrylate-based composite. The composites were tested at 23°C, and after preheating at 55°C. Five specimens were prepared for each experimental group. The top surface of the specimens was irradiated for 20 s using an LED unit. Vickers microhardness test was used to evaluate both top and bottom surfaces of the specimens, followed by 24-h storage in the dark. Statistical analysis was performed using one-way anova and Tukey's post-hoc test at a level of significance of α = 0.05. Results There was a significant rise in microhardness as the temperature increased from 23 to 55°C for both the top and bottom surfaces of the tested composites ( P < 0.05). The C2 shade of both composites exhibited the lowest microhardness ( P < 0.05), while the A2 and A3 shades did not show significant differences compared to each other ( P > 0.05) Filtek Silorane presented significantly lower microhardness than Filtek Z250 ( P < 0.05), regardless of the temperature, shade, or depth of measurement. Conclusions Preheating, shade, and composition of the tested composite resins affected their surface microhardness. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study was to evaluate the fluoride release ability, during a 30-day period and the fluoride recharge ability, after 0.02% and 0.04% NaF solution treatments, of five fluoride-releasing restorative materials (Fuji IX GP, Ketac N100, Dyract Extra, Beautifil II, and Wave) and three fluoride-releasing dental adhesives (Stae, Prime & Bond NT, and FL-Bond II). Eight disk-shaped specimens for each material were prepared. Fluoride release was measured using a fluoride ion selective electrode daily for 30 days. For refluoridation procedures, the specimens were immersed in 0.02% NaF for 5 min. Fluoride measurements were carried out at 24 hr intervals for 5 days. This refluoridation regime was repeated twice, and measurements were again recorded. After 15 days, the same procedure was carried out using 0.04% NaF. During the 30-day period, Fuji IX GP released the highest amount of fluoride among the restorative materials while Prime & Bond NT was the highest among the dental adhesives. After NaF solution treatments, Fuji IX GP again ranked the highest in fluoride release among the restorative materials while FL-Bond II ranked the highest among dental adhesives. It was concluded that fluoride recharge abilities of fluoride-releasing dental materials depend on their compositions and setting mechanisms and that low-concentration fluoride solutions which are indicated for children affect fluoride re-release. [ABSTRACT FROM AUTHOR]

Accidental ingestion of instruments or their components is a possible complication of dental treatment. Although in many cases the foreign object can pass through the gastrointestinal tract without any need for surgical intervention to retrieve it, sometimes such incidents can be life-threatening. This paper reports a case of accidental ingestion of an airwater syringe tip during routine dental treatment for which endoscopic retrieval was required. The present case highlights the need for dental professionals to be aware of the fact that dental equipment comprising multiple components may be associated with a risk of accidental detachment of a component and its ingestion or aspiration by a patient receiving treatment. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to measure the temperature increase induced by various light-curing units during photo-polymerization beneath ceramic restorations., Methods: Three light-curing units were used; a high intensity QTH unit Elipar 2500 and two LED units: Translux Power Blue and Excelled 1400. The 15 ceramic specimens (CEREC Blocks) used in this study were of 2.5 mm thickness, 5 mm wide and 6 mm long and made using a slow speed saw. Using the same slow speed saw the occlusal enamel portion of 15 mandibular third molars was removed and 15 dentin discs of 1 mm height were prepared. The thickness of the luting cement was delimited to 0.5 mm, using a Teflon mold and then brought into contact with the dentin disc. Light-curing time for all the groups was 20 sec. The temperature rise was measured placing underneath the dentin disc a K-type thermocouple wire connected to a data logger. Five measurements were carried out for each group. Statistical analysis was performed using ANOVA (a=0.05)., Results: The results indicated that there was a lower temperature rise induced from Translux Power Blue than from the other two light-curing units, which did not present statistically significant difference (p<0.05). However, temperature rise from the light-curing units used in this study is lower than 5.5°C, which is the limit of pulpal damage., Conclusions: Within the limitations of this study, although the type and characteristics of light-curing units may affect temperature rise under ceramic restorations, this influence is possibly not of clinical significance.