Relationship between dental fluorosis, dental caries and salivary levels of Streptococcus mutans.

Background and Objective: Worldwide, dental caries is an endemic infection and a significant public health problem. Fluoride reduces caries by helping to prevent demineralisation, by remineralising early carious lesions, and by decreasing the activity and growth of Streptococcus mutans (S. mutans). Fluoride intake above the optimal levels leads to a condition known as dental fluorosis, which causes hypo-mineralisation of the tooth. Some studies have revealed that the severity of fluorosis is directly proportional to caries, but some showed opposite results. Hence, with these contradicting results, this study was undertaken to identify the relationship between different grades of dental fluorosis, dental caries and the most common cariogenic bacteria S. mutans in saliva. Materials and Methods: A total of 90 subjects within 14- to 16-year age range were selected and categorised depending on the severity of fluorosis into three groups: group I (mild), group II (moderate) and group III (severe) based on modified Dean's fluorosis index criteria (1942). Unstimulated whole saliva samples were collected using the oral rinse technique and processed for quantification of S. mutans using Mitis Salivarius Bacitracin Agar medium. The number of colony-forming units (CFUs) was determined using a colony counter and expressed as ≥102, ≥103, ≥104 and ≥105 CFUs per ml of the sample, in accordance with the scale recommended by the manufacturer (HiMedia Laboratories). The severity of the caries was measured using decayed, missing or filled teeth (DMFT). Results: Observations revealed that the overall DMFT was directly proportional to the level of S. mutans titres. It was observed that 67 to 73% of participants showed fewer colony counts (102 and 103) with minimal DMFT scores and 27 to 33% showed higher counts (104 and 105) with higher DMFT scores in all the groups. 105 CFUs of group III showed the highest mean DMFT scores (2.9) with an increased number of involved subjects than group II (2.3) and group I (1.5). In all, male participants had higher bacterial titres and DMFT scores than females. Conclusion: Fluoride in the drinking water served as anticariogenic agent regardless of the severity of fluorosis. Severe fluorosis with a higher incidence of caries and increased CFUs of S. mutans clearly indicates the importance of preventive measures and early treatment to reduce the severity of fluorosis and prevalence of dental caries.

Stromal changes in apparently normal mucosa of smokers and pan chewers: a multi-parametric approach

Aim: To compare and contrast the various changes in the connective tissue among patients with the habits of smoking, pan chewing and controls by using fluorescence spectroscopy, histopathology and transmission electron microscopy. Method: Thirty subjects were categorized into three groups: pan chewers, smokers and controls without any oral lesions. Fluorescence spectroscopy was carried out using FLUOROMAX-2. Excitation spectroscopy was performed at 280 and 320nm respectively and Emission spectroscopy was performed at 340 and 390nm excitation. Subsequently, histopathological evaluation and transmission electron microscopy was done for biopsies taken from test groups and controls. Results: The mean, standard deviation and test of significance of mean values between different groups for intensity-380nm, intensity–420nm and intensity – 460nm at 320 nm excitations, showed that the Mean values in group I and group II were significantly higher than the mean value in group III with a p-value of less than 0.001. Considering the histopathological parameters, the pattern of the sub-epithelial connective tissue, the presence of chronic inflammatory cells and lysis of connective tissue was significant. The ultrastructural analysis revealed the presence of epithelioid, spindle or elongated and stellate shaped fibroblasts in the connective tissue. Conclusion: In this pilot study, we could find variations in emission characteristics of various amino acids which correlated with histopathology and electron microscopy. Our study suggests that there are connective tissue changes in oral mucosa among smokers and pan chewers, though it is apparently normal in clinical presentation. These initial connective tissue changes could determine the progression of altered mucosa to a pre-cancer or cancer, which is further related to other complex interactions. Elaborate studies are required to evaluate the significance of our hypothesis.