Cariogenic Potential of Infant Formulas-An In Vitro Study.

Objectives: To compare the in vitro cariogenic potential of two infant formulas (IF, for ages 6-12 months) processed with sterile distilled water with or without 1 ppm fluoride. Study design: Nine specimens in each water type were inoculated with Streptococcus mutans (SM) suspension. The specimens were then divided into one group of samples cultured immediately on Mitis salivarius (MS) agar plates (T0) and another group of specimens cultured on MS agar plates after incubation at 37°C for 4 hours in anaerobic conditions (T4). Six-fold dilutions of each sample were incubated for 48 hours, and colony-forming units (CFUs) of SM were numerated. The pH changes associated with bacterial fermentation of each of the suspensions were measured at T0 and at T4 following incubation. Results: The pH was lower at T4 than at T0 in both IF. The SM colonies increased significantly at T4 compared to T0 in both IF (P < 0.001). There was no significant difference between the CFUs of the mediums at T0 and T4 or relation between SM colonies of IF based on fluoridated and non-fluoridated distilled water. Conclusion: The cariogenic potential was not significantly different between two IF prepared with fluoridated or non-fluoridated distilled water.

The effect of commonly used sutures on inflammation inducing pathogens - an in vitro study.

INTRODUCTION: Sutures are a vital part of nearly every surgical procedure designed to close and stabilize wound margins consequently allowing undisturbed wound healing. AIM: The aim of this study was to evaluate in vitro antimicrobial effect of 4 commonly used sutures. MATERIALS AND METHODS: The Direct Contact Test was used to evaluate the antibacterial properties of 4 types of sutures: 2 absorbable and 2 non-absorbable braided sutures, immediately or after aging for 2 or 7 days. The tested bacteria were: Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa. Three-way ANOVA, two-way ANOVA, one-way ANOVA and Tukey multiple comparison were used for statistical analysis. RESULTS: The absorbable Vicryl Plus exhibited a bactericidal effect against the Staphylococcus strains, which was unaffected by aging. With P. aeruginosa, there was only an initial delay in bacterial growth. All other tested sutures did not have antibacterial effects against any of the tested bacteria (p < 0.001). CONCLUSIONS: Vicryl Plus had sustained bactericidal effect against the Staphylococcus strains but not against P. aeruginosa. None of the other sutures presented any antibacterial properties.

Salivary Candida, caries and Candida in toothbrushes.

BACKGROUND: Candida species are common inhabitants of the normal oral microbiota. A few studies founded a relationship between high levels of Candida albicans in the oral cavity and high DMF scores. Toothbrushes can also be reservoirs of microorganisms, the proliferation of these microorganism on a toothbrush could be a major factor for its distribution in the oral cavity. AIM: To examine the associations between salivary Candida and DMF, and between salivary Candida and Candida in the toothbrush. METHOD: 46 healthy school children, who attended a University pediatric dental clinic, were tested for Candida in their saliva and in their toothbrush. Their DMF was recorded. RESULTS: 38 children were Candida-positive (79.2%), out of whom 5 demonstrated a positive growth of Candida in the toothbrushes. No correlation was found between Candida in the saliva and in the toothbrush. The number of Candida-positive girls was significantly higher than the number in boys. No significant relationship between caries experience and the presence of Candida was found CONCLUSIONS: No correlation was found between Candida in the saliva and in the toothbrush. The origin of the Candida in the toothbrush is not totally clear.

Antibacterial efficacy of a new chlorhexidine slow release device to disinfect dentinal tubules.

Dentinal tubules of 27 cylindrical bovine root specimens were infected with Enterococcus faecalis. In nine specimens, 5% chlorhexidine was placed in a slow-release device (Activ Point) for 7 days, in another nine irrigation with 10 ml of 0.2% chlorhexidine was used, and the remaining nine served as positive control. Powder dentin samples obtained from within the canal lumina using ISO 025 to 033 burs were examined for the presence of vital bacteria by inoculating brain-heart infusion plates and counting colony forming units. Results were analyzed using analysis of variance and covariance with repeated measures. Heavy bacterial infection was observed at the layer close to the lumen in the control specimens, decreasing rapidly from layer to layer up to the deepest layer tested (400-500 microm), which contained several hundred colony forming units. Viable bacteria in each layer of dentin were significantly reduced with chlorhexidine irrigation solution (p < 0.01) and were completely eliminated with the chlorhexidine slow-release device (p < 0.01).

Surface antibacterial properties of fissure sealants.

PURPOSE: Sealants form a physical barrier between the oral environment and deep fissures that contribute to caries prevention. It is postulated that sealants possessing antibacterial properties are advantageous. The purpose of this study was to evaluate the antibacterial properties of four pit and fissure sealants using direct contact test (DCT) and agar diffusion test (ADT). METHODS: For the DCT, 8 samples of Helioseal F (Vivadent), Ultraseal XT (Ultadent-Weldent), Conseal F (SDI), and Dyract Seal (Dentsply) were placed on the sidewalls of wells of a 96-microtiter plate. After polymerization, freshly grown Streptococcus mutans cells (circa 1 x 10(6)) were placed on the surface of each sample for 1 hour at 37 degrees C. Fresh media was then added to each well and bacterial growth was followed for 16 hours by temperature-controlled spectrophotometer. Similarly prepared samples were aged in phosphate buffered saline for 14 and 30 days and the DCT was repeated. The ADT was performed by placing samples in uniform wells punched in agar plates. RESULTS: Freshly polymerized samples in the DCT, Dyract Seal and Ultraseal XT possessed prominent antibacterial properties. Dyract Seal also demonstrated the most potent antibacterial properties, which lasted 14 days but faded within 30 days. In ADT, the halo in the bacterial lawn was measured after 48 hours, and only Dyract Seal demonstrated an inhibition zone. CONCLUSIONS: The compomer-based sealant Dyract Seal possessed the most potent and longest lasting antibacterial activity.