Dentin bonding agent with improved bond strength to dentin through incorporation of sepiolite nanoparticles

The study aims to investigate the effect of incorporation of sepiolite nanoparticles on the microtensile bond strength of an experimental dentin bonding to the human dentin. The sepiolite nanoparticles were incorporated into an experimental methacrylate-based dentin bonding system in concentrations of 0.0, 0.2, 1.0, 2.0, and 5.0 weight percents. The specimens were then ultrasonicated to finely disperse the nanoparticles in the adhesive matrix. The coronal enamel of 30 intact human premolars was cut to expose dentin. Having etched, rinsed, and blot dried the experimental bonding agents were applied to dentin surface. Adper Single Bond was used as control group according to the manufactor?s instruction. Then all the teeth were built up by composite and sectioned in stick form for microtensile test. The fracture surface was observed using SEM. The data were analyzed by ANOVA and Tukey?s post-Hoc test. The results indicated that the incorporation of the nanofiller, improved the bond strength to dentin with the highest values obtained at 1 w% sepiolite nanoparticle content. Sepiolite nanoparticles can be considered as novel fillers to improve the mechanical properties of dentin bonding agents

Evaluating the relationship between dental caries number and salivary level of IgA in adults

Dental caries are the most common mouth infectious disease and also chronic disease of childhood. Saliva plays different roles in oral cavity; for example, salivary immunoglobulins play significant role in body and oral immunity. Various studies were conducted on the different effects of IgA on oral cavity, especially dental caries, and reported controversial results. The current study aimed to compare salivary IgA level at different stages of dental caries in adults. A total of 40 adults, aged 20 to 40 years, referred to the department of oral medicine at Qazvin Faculty of Dentistry, were selected voluntarily based on the number of decayed teeth. Their unstimulated saliva was collected by the spitting method. The cases were assigned to 4 groups each of 10, based on the number of decayed teeth, as follows: Group 1: Caries free, Group 2: With 1 or 2 decayed teeth, Group 3: With 3 or 4 decayed teeth, and Group 4: With 5 or more decayed teeth. None of the cases had systemic diseases or the history of using medicines which affect the quality or quantity of saliva. The salivary IgA level of the cases was measured immunoturbidometrically and analyzed by ANOVA and t test. Significant difference was observed between the groups 1 and 4, but there was no significant difference between the other groups. According to the results of the current study, the salivary IgA can be considered as an index for the function of immune system, which may be increased by the number of decayed teeth. In fact, the increase of salivary IgA is just the response of immune system to the accumulation of microorganisms and may be the attempt of body to control them

Evaluation of the efficacy of DIAGNOdent Laser in Comparison with Clinical Observation Technique in Occlusal Caries Diagnosis

Background and Aim: Considering the high prevalence of dental caries, early detection of occlusal caries, which is difficult is very important. The aim of this study was to evaluate the efficacy of two methods of clinical observation and DIAGNOdent laser in the diagnosis of occlusal caries. Materials and Methods: In this experimental study, 75 qualified molar teeth were evaluated for occlusal caries by clinical observation and DIAGNOdent laser techniques. Then, after caries removal (as gold standard), the depths of cavities were measured with a probe. Finally, data analysis was performed using SPSS 21 software and kappa test. Efficiency, agreement and correlation between the mentioned methods were determined. Results: The efficacy of occlusal caries detection is significant in both clinical observation and DIAGNOdent methods compared to the gold standard (For both: P = 0). According to evaluation of agreement with gold standard, Kappa value was 0.59 for clinical observation and 0.29 for DIAGNOdent laser. Evaluation of the correlation between the two methods, the r value for clinical observation and gold standard was 0.7 and for laser and gold standard was 0.54. Conclusion: The significant relationship between both clinical observation and DIAGNOdent laser with gold standard showed occurrence of diagnostic error in both methods. However, clinical observation is a more effective way to evaluate early occlusal caries in comparison to DIAGNOdent. Clinical observation and the gold standard also have a direct and relatively strong relationshi

Effect of incorporation of amorphous calcium phosphate on bonding strength of a dental adhesive

Amorphous calcium phosphate (ACP) which is a transient phase in natural bio-mineralization process has recently gained the spotlight. This study aimed to assess the effect of incorporation of nano-ACP (NACP) in a dental adhesive with/without surface treatment with silane coupling agent on bond strength. NACP was synthesized by the wet chemical precipitation technique. To characterize the structure of NACP, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy were used. Forty molars were randomized into 4 groups of 10. The teeth were restored with composite resin and the bonding agent (one of the four groups). Adper Single Bond 2 was used as the control group. In 4wt% NACP group, NACP fillers were added to the bonding agent. In 0.4wt% and 4wt% SNACP groups, silanized NACP fillers were added to the bonding agent. Finally, the mode of failure of specimens was determined. Data were analyzed by one-way ANOVA and Tukey's post-hoc tests. P<0.05 was considered statistically significant. Addition of 4wt% non-silanized NACP decreased the bond strength compared with the control group (P<0.05). The bond strength of the groups with silanized fillers was not significantly different from that of the control group. Addition of silanized NACP to dental adhesive had no significant adverse effect on bond strength, which is a promising finding to pave the way for the synthesis of bonding agents containing bioactive fillers