Effect of Prolonged Water Aging on the Bond Strength and Marginal Seal of Three Novel Restorative Materials.

AIM: To assess and contrast the shear bond strength (SBS) and microbial leakage of Cention-N, Fuji IX, and nanohybrid composite restorative materials after being exposed to prolonged water aging. MATERIALS AND METHODS: A total of 30 self-curing acrylic blocks were prepared for SBS analysis. Extracted teeth were affixed on the acrylic resin to incorporate the root section. To expose the occlusal dentin, 3 mm of the midcoronal portion was sectioned. The sectioned samples were allocated into the following three groups: Group I: Fuji IX; group II: Filtek Z350; and group III: Cention-N. Cylindrical plastic tubing was used to place each material as directed by the manufacturer and water aging for 7, 14, and 28 days at 37°C. Also, a universal testing machine (UTM) was utilized for testing followed by a scanning electron microscope (SEM). For microleakage analysis, a total of 30 class-V cavities were prepared. The prepared samples were allotted to respective groups; Later, 200 thermocycles at 5°C and 55°C were applied for 30 seconds to mimic the oral environment. The root apices sealed with sticky wax and the exception of a 1-mm around the edges of the restorations were then painted twice with clear nail varnish and submerged in 0.5% basic fuchsin dye at 37°C. Samples were washed, dried, and sectioned longitudinally followed by stereomicroscopic evaluation. RESULTS: Groups I (0.083), group II (0.083), and group III (0.102) did not show significant variation in the SBS after water degradation. At the end of 28 days of water aging, group III showed 33.3% adhesive failure and 66.7% mixed failure mode. For marginal leakage in group III, the mean and standard deviation (SD) were 334.90 ± 418.454 with the p = 0.001 showing a significant difference compared to groups I and II. CONCLUSION: Compared to nanohybrid composite and Fuji IX, Cention-N showed a superior SBS after being exposed to water aging and exhibited lesser marginal leakage. CLINICAL SIGNIFICANCE: Cention-N outperformed in its marginal adaptation with superior shear resistance and can be considered as an alternative bulk filling material.

Estimation of the Efficacy of Remineralizing Agents on the Microhardness of Deciduous Teeth Demineralized Using Pediatric Formulations.

AIM: This study aimed to evaluate the demineralizing effect of commonly used pediatric syrup formulations on primary teeth and the efficacy of two readily available remineralizing agents in treating this effect. MATERIALS AND METHODS: Ninety primary teeth were used for sample preparation and divided into three groups: antibiotic syrup (group A), cough syrup (group B), and control (group C) groups. These groups were further categorized into intragroups according to the treatment with remineralizing agents: groups A1, B1, and C1 received GC Tooth Mousse (casein phosphopeptide-amorphous calcium phosphate, CPP-ACP paste) and groups A2, B2, and C2 received Clinpro Tooth Crème. The samples were subjected to a series of demineralization cycles for 14 days, and remineralization cycles until 30 days were performed using two remineralizing agents, that is, GC Tooth Mousse (CPP-ACP paste) and Clinpro Tooth Crème and were evaluated using Vicker's microhardness test. RESULTS: Antibiotic syrup (group A) and cough syrup (group B) showed a significant decrease in surface microhardness compared with control (group C). All intragroups showed an increase in surface microhardness after treatment with remineralizing agents, which was significantly higher in intragroups A1, B1, and C1 treated with GC Tooth Mousse (CPP-ACP paste). CONCLUSIONS: Oral liquid medications showed definite demineralization potential. CPP-ACP paste was found to be better than Clinpro Tooth Crème for demineralized teeth. CLINICAL SIGNIFICANCE: The use of over-the-counter drugs has increased among the average Indian population, especially for the treatment of fever, cold, and cough. Unwise use of medications by the present population without proper medical guidance will lead to irreparable changes in future generations.

Evaluation of Probiotic Effects of Lactobacilli on Mutans Streptococci: An In Vitro Study.

AIM: The aim of the present study is to evaluate the probiotic effect of Lactobacillus acidophilus and Lactobacillus rhamnosus on clinical isolates of Mutans Streptococci (MS) and antibiotic susceptibility of these strains to commonly used antibiotics in dentistry. MATERIALS AND METHODS: Plaque samples from permanent first molars were collected and transferred aseptically onto Mitis-Salivarius agar and incubated at 37°C for 24 hours in the presence of 5-10% CO2. Mutans streptococci colonies were identified biochemically using Hi-Strep identification kit. The inhibitory activity of the clinical strains of MS on Lactobacilli was investigated using agar-overlay interference technique. Positive inhibition was appreciated as a clear zone around the Lactobacilli. Disk diffusion assay was done as described by CLSI M100-S25 for antibiotic susceptibility. The zone of growth inhibition caused by Lactobacilli and antibiotics on MS clinical strains was measured directly using a vernier caliper. Statistical analysis was done using independent t-test. RESULTS: Mutans streptococci exhibited positive inhibition with both the probiotic strains and L. acidophilus showed more zones of inhibition than L. rhamnosus. Antibiotic susceptibility of clinical strains of MS showed sensitivity to penicillin and vancomycin, however, tetracycline and erythromycin showed very few resistant strains. The highest zone of inhibition was shown by cephalothin followed by penicillin, tetracycline, ciprofloxacin, erythromycin, and vancomycin. CONCLUSION: L. rhamnosus and L. acidophilus have strong inhibitory effects on clinical strains of MS. Lactobacillus acidophilus showed a higher zone of inhibition. All the clinical strains of MS were sensitive to penicillin and vancomycin. The highest zone of inhibition was shown by cephalothin. CLINICAL SIGNIFICANCE: Dental caries remains silent epidemic and increasing antibiotic resistance is another major challenge that threatens the world. Newer methods such as whole-bacteria replacement therapy using probiotics for decreasing harmful oral pathogens and reducing the intake of antibiotics must be explored. More researches to promote use of probiotics should be initiated due to its possible preventive and health maintenance benefits providing an end to new cavities and antibiotic resistance.