Aim: To evaluate the antibacterial potential of dental cements on the growth of the colonies of Streptococcus mutans. Materials & methods: Ten Discs were prepared from three types of bioactive materials; light cure calcium hydroxide, light cure resin modified glass ionomer, and Biodentine. Bacterial Strain S. mutans was suspended in Tryptone Soy Broth (TS) medium and incubated for 18 h. Agar diffusion test was used to evaluate the antibacterial activity by measuring the gauge of inhibition zone around the discs. Statistical analysis was performed by using one-way Anova test and differences were considered significant at the 95% confidence level (P < 0.05). Results: A significant difference of antibacterial characteristics between groups at p 0.001. Biodentin had the largest inhibition zone (15.14 ± 0.34), followed by Resin modified glass ionomer (11.22 ± 0.13). Light cured Calcium hydroxide showed the smallest inhibition zone (9.15 ± 0.3). Conclusion: While Biodentin showed the strongest antibacterial properties, the VLC bioactive glass ionomer and calcium hydroxide cements are also effective as standard pulp-capping products in inhibiting the growth of S. mutans organism commonly found at the base of a cavity preparation.

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Introduction: Despite of the recent advances in the adhesive dentistry, high possibility of microbial biofilm development at the resin restoration surfaces may lead to marginal gaps and recurrent caries. Degree of conversion of the dental adhesive represents a relative assessment to its quality, and a direct correlation with its mechanical behavior. This in vitro study was carried out to investigate the minimum inhibitory concentration of antimicrobial silver nanoparticles incorporated in two forms into the self-etch adhesive system and the effect of their incorporation on the degree of conversion of the self-etch adhesive. Methods: Minimum Inhibitory Concentration of the self-etch adhesive system incorporated with nanosilver powder and solution against Streptococcus mutans was tested using an agar diffusion test. The effect of nanosilver incorporation (powder and ethanol-based solution) in the self-etch adhesive system on its degree of conversion was assessed using Attenuated Total Reflectance/ Fourier Transform Infra-Red spectrometer (ATR/ FTIR). Results: The results showed that silver nanoparticles incorporation (powder or ethanol based at 12.5 µg/ml concentration) significantly increased the antibacterial efficacy of the self-etch adhesive against Streptococcus mutans (P< 0.05). Nanosilver powder possessed higher significant antibacterial effect when compared to silver ethanol based solution (P< 0.05). Degree of conversion of self-etch adhesive containing nanosilver powder showed non-significant difference from the control group (p > 0.05). In contrast, self-etch adhesive with nanosilver solution recorded significantly lower values when compared to the control or nanosilver powder group (P< 0.05). Conclusion:  The antibacterial efficacy of the adhesive system can be greatly potentiated with the addition of silver nanoparticles (12µg/mL concentration) especially the nanosilver powder. Incorporation of the antibacterial nanosilver powder in the adhesive system didn’t compromise the degree of conversion of the adhesive resin.

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Aim: This study aimed to compare the diagnostic predictive values of a light induced fluorescence intra oral camera (VistaCam iX) versus visual assessment method (ICDAS-II) in identification of occlusal carious lesion. Methodology: Occlusal surfaces of 199 molar teeth from 43 adult patients who fulfill the eligibility criteria were examined by two observers using two diagnostic methods. The teeth were firstly assessed visually according to the criteria of the International Caries Detection and Assessment System (ICDAS-II) then by fluorescence camera. Inter observer agreement was measured for ICDAS-II using Kappa and weighted Kappa Values and for the camera using inter class correlation (ICC). Correlation between methods was calculated using Spearman's rank correlation coefficient (r s) and the Receiver Operating Characteristic (ROC curve) between the tested methods was estimated. Results: Significant positive correlation was found between the ICDAS-II and the camera measurements (r s = 0.8739, P< 0.001). The area under the ROC curve was (0.932, p< 0.001) indicating a great association between the two tested methods when selecting adequate cutoff values for the camera. There was a statistically significant agreement between the two observers for ICDAS-II values (Kappa =0.8125, weighted Kappa = 0.8558). Excellent inter examiner agreement was found between the two observers when using the FC, ICC = 0.9774 (95% CI, 0.789 to 0.889), (p<0.001). Conclusion: The camera showed high reliability and agreement with ICDAS-II for initial occlusal caries detection. Sensitivity and specificity values for the camera varied depending on the cutoff value.

Aim: This study was conducted to evaluate bulk fill and nanohybrid resin composite at different cavity depth and after different testing periods. Materials & methods:Standardized simple box class II occluso-mesial (OM) cavities were prepared in the selected first maxillary premolar in each quadrant. The cavity depth was adjusted to be either 2mm or 4mm in each patient. For the bulkfill composite, both the two and four-millimeters cavities, one increment of the resin composite material (Xtra-fil) was packed inside the cavity while for the nanohybrid resin composite (Grandio), the four millimeters cavities were filled incrementally by packing two increments of 2mm thickness while for the two millimeters cavities one increment (2mm) was packed to fill the cavity and light cured for 20 seconds, finished, polished and left for the assigned time. The restored tooth was extracted atraumatically and teeth were sectioned to produce beam-shaped specimens of (1 ± 0.1 mm 2 ). The beam specimens were attached with cyanoacrylate gel to fit the Instron Universal testing machine. The tensile load was applied at a cross-head speed of 0.5mm/minute until specimen failure occurred. At this point the failure load in Newton was recorded.Results: Cavity depth of 2 mm showed the highest significant mean microtensile bond strength compared with that of 4 mm. Nanohybrid resin composite showed the highest significant mean micro tensile compared with Bulkfill resin composite. The testing period of 24 hours showed highest significant mean microtensile bond strength that one tested after 3 and 6 months. Conclusion:(1) cavity depth has an apparent influence on tensile bond strength of the tested restoratives to dentin. (2) Microtensile bond strength of the tested restorations deteriorates by aging.