Evaluating the Efficacy of Chemical Disinfectants on Contaminated Dental Materials Contaminated by An Airborne Disease Tuberculosis Similar to COVID-19.

BACKGROUND: Tuberculosis (TB) is a communicable disease as well as an airborne disease. Mycobacterium tuberculosis (MTB) could survive on dental materials shipped to dental laboratories. AIMS: The aim of this study was to determine the number of bacilli held on the prosthetic material and the effect of chemical disinfection agents on various prosthetic materials that were shipped to dental laboratory of TB patient. MATERIALS AND METHODS: The study consisted of three study groups, and a control group. 10 mm x 2 mm disc-shaped (n = 18 for each group, n = 72 in total) nickel-chromium alloy (Ni-Cr), polymethylmethacrylate (PMMA), and dental ceramic (DC) samples were prepared. After exposure to MTB 24 hours in a 37°C incubator, six samples for each group (PMMA), Ni-Cr alloy and a control group DC samples) were exposed to three disinfectants; 10 minutes into 2% glutaraldehyde, 10 minutes into 5% sodium hypochlorite, and 1 minute into alcohol-based disinfectant after vortexed in distilled water. Colony forming units (CFU/ml) were calculated per milliliters. Two-way ANOVA statistical analysis method was used, and a P value less than 0.05 was considered as significant. RESULTS: The bacteria count for six Ni-Cr alloy disc-shaped specimens were recorded as 40, 10, 8, 6, 5, and 4 CFU/ml, respectively. Intensity of the colonies were found to be lower in other groups. 5 CFU/ml were detected on a single PMMA sample in the control group, and 40 CFU/ml were detected on one of the dental ceramic sample. No MTB uptake was observed on any sample in the 2% glutaraldehyde and 5% NaOCl disinfectant study groups. In alcohol-based disinfectant group, 1 CFU/ml was observed on Ni-Cr alloy sample. The effect of prosthetic materials used in this experimental study were not statistically significant on the CFU (p = 0.293). However, the disinfectants use was statistically significant on the number of colonies (p = 0.004). CONCLUSION: NaOCl and glutaraldehyde appeared to be more effective than alcohol-based disinfectant in removing MTB from Ni-Cr alloy, PMMA and dental ceramic surfaces.

Surface roughness of fluoride-releasing restorative materials after topical fluoride application.

AIM: The aim of this study was to assess the effect of a single application of two topical fluoride agents: NNaF and APF (2% neutral sodium fluoride gel and 1.23% acidulated phosphate fluoride gel, respectively) on the surface roughness (Ra) of Fuji IX GP, Ketac N100, Vitremer, Dyract AP, Compoglass F and Filtek Ultimate. STUDY DESIGN: The effect of NNaF and APF on the surface roughness of fluoride-releasing restorative materials was tested on disk-shaped material specimens with a surface profilometer. METHODS: All materials were handled according to manufacturer's instructions. ISO standardised specimens were prepared for each material and then stored in distilled water for 24 hr. Each sample was polished with 600 and 1200 grit sandpaper on both sides while keeping the material surface wet. Ra measurements were performed on untreated specimens initially and after 1 min, 4 min and simulated 2-years for both fluoride applications, respectively. The mean Ra values for all specimens were measured using a surface profilometer. STATISTICS: Differences in surface roughness values were assessed using paired t-test. The differences between the experimental groups were analysed with one-way ANOVA; p<0.05 was accepted as statistically significant. RESULTS: The results of the present study indicated that Ra values for Fuji IX GP and Vitremer increased significantly after all APF, but not NNaF applications. All tested materials exhibited increased Ra values for both treatment regimes, but this was not found statistically significant. CONCLUSION: APF gel application significantly increased the surface roughness of both Fuji IX GP and Vitremer for all time periods.