Periodontal disease in a remote Asian population: association between clinical and microbiological parameters.

OBJECTIVE: The aim was to clinically and microbiologically describe the periodontal conditions in a remote adult Asian population with poor oral hygiene. METHODS: The subjects were 30-60-year-old adults of Karen Hill tribes with no access to dental care. Eighty-six subjects were selected randomly. Clinical registrations included number of remaining teeth, plaque index (PlI), bleeding on probing (BoP), clinical attachment loss (CAL), and probing pocket depth (PPD). Subgingival plaque samples were collected and analyzed with the checkerboard method. RESULTS: Subjects of the study group had mean number of remaining teeth of 26.5 despite the abundant plaque and a high bleeding score. Severe periodontitis (CAL ≥ 7 mm) was recorded in 12.9% of the youngest age group (30-39 years) while it was significantly higher (52%) in the middle group (40-49 years) and (60%) in the eldest age group (50-60 years). Pathological pocketing (PPD ≥ 7 mm) was significantly lower in all age groups. Age, betel chewing, and a microbiological cluster including at least one of Prevotella tannerae, Filifactor alocis and Porphyromonas endodontalis significantly correlated with the severity of periodontal disease. CONCLUSION: Age, betel chewing, and a new bacterial complex other than the "red complex" correlated to periodontal breakdown in this remote adult Asian population.

pH and bacterial profile of dental plaque in children and adults of a low caries population.

OBJECTIVE: This study compares pH and microbiological profile of dental plaque in children and adults of a low caries population. MATERIAL AND METHODS: Thirty-nine children, 12-14 years of age and 45 adults between 20 and 39 years of age in 5 Karen villages of the Tak province, Northern Thailand were examined for plaque, calculus, caries (DMFT) and pH measurements in resting plaque and after a sucrose rinse. Information on dietary and oral hygiene habits was obtained through interviews using a fixed questionnaire. Microbiological profile of plaque samples was analyzed with DNA-DNA checkerboard technique. RESULTS: Mean DMFT was 0.77 ± 1.56 and 87% of the adults and 67% of the children were caries free (p < 0.05). The mean resting pH was for both age groups in the range of 7.0-7.1 and significantly higher than a Swedish caries free reference group. Karen adult men had significantly lower pH minimum than females and children (p < 0.05). Supragingival plaque samples showed high levels of low acidogenic and anaerobic species, which dominated over strong acid producers such as streptococci. CONCLUSION: The study indicates that the Karen children and adults has a plaque physiology and microbiology predominating by low acidogenic anaerobes, which in addition to the low sucrose intake explains the low caries prevalence in this population.

Oral microflora in betel-chewing adults of the Karen tribe in Thailand.

OBJECTIVE: To study a possible influence of betel chewing on the composition of the oral microflora in plaque and saliva and on oral health parameters as well as a possible betel effect on oral bacteria in vitro. MATERIAL AND METHODS: Thirty-two adults (16 betel chewers and 16 non-betel-chewing controls) of the Karen Hill tribe in Thailand were investigated. Saliva samples and 2 pooled supragingival plaque samples were taken from each individual for microbial analysis with culture and 4 subgingival samples for analysis with the DNA-DNA hybridization method against 12 periodontitis associated bacterial species. Caries (DMFS), plaque (PlI%) and bleeding on probing (% BoP) was registered as well as number of sites with >5mm probing pocket depth (PPD). Water extract of the betel (areca chatechu) nut was tested for its antimicrobial effect in vitro against 10 oral bacterial species with the agar diffusion method. RESULTS: An antimicrobial effect of betel nut water extract was found on the oral microorganisms in vitro. The levels of mutans streptococci and lactobacilli in saliva were low or absent in both chewers and controls. The prevalence of the periodontitis associated bacteria was >90%. Betel chewers had significantly lower levels of some bacteria in subgingival plaque (Prevotella intermedia p<0.001) than non-chewers. This study population was low in missing teeth (mean 0.7 and 0.3), caries decay (DS 2.1 vs 1.6), and number of deep pockets (mean 1.9 vs 1.3). Great variation in oral hygiene (PlI and BoP) between the subjects was seen. CONCLUSIONS: An antimicrobial effect of the betel nut was found in vitro and with a possible effect also in vivo; however it did not seem to influence clinical parameters such as plaque index, caries prevalence (DMFS), bleeding on probing and number of deep pockets.