Oral Microbiota, Caries and Periodontal Status in Smokeless Tobacco chewers

Objectives: This study compared dental caries, periodontal disease status in relation to oral microorganisms amongst smokeless tobacco chewers and non-chewers. Methods: A sample of 42 smokeless tobacco chewers and 42 non-chewers (age range 20-60 years) were assessed for dental caries, periodontal disease status using Decayed Missing Filled Surface (DMFS), Community Periodontal Index (CPI) and Loss of Attachment (LOA) indices. In addition, samples of stimulated saliva and sub-gingival plaque were collected from each subject for culture-based analysis of 20 types of oral microorganisms. Statistical analysis compared the Colony-forming units (CFU) between smokeless tobacco chewers and non-chewers by Mann-Whitney U test. Caries experience was compared by t-test. Results: Caries experience among chewers was significantly less at 61.9% (mean DMFS=3.5) compared to non-chewers 90.5% (mean DMFS=5.5) (p<0.05). Deep pockets measuring more than 5.5mm were seen among 26.2% of chewers and 19.1% non-chewers with no significant differences between the two groups (p>0.05). No significant differences were also observed for attachment loss (0-3mm) between chewers (42.9%) and non-chewers (40.5%) (p>0.05). Species of Lactobacilli were significantly lower among chewers (median CFU = 0.788) than non-chewers (median CFU = 1.52) (p<0.05). Gram-negative pigmented bacteria including Prevotella and Porphyromonas species had a median CFU of 0.004 in chewers and 0.15 in non-chewers, whereas Fusobacterium species had a median CFU of 0.002 in chewers and 0.1 in non-chewers (p< 0.05). Conclusions: The higher percentage of caries amongst non-tobacco users can be explained by greater numbers of Lactobacillus and other acid producing species in this population. Chewers of tobacco experienced a slightly higher occurrence of periodontal disease than non-users. These clinical observations suggest lower ability of gram-negative bacteria to mediate more disease in this population.