Mercury exposure and periodontitis among a Korean population: the Shiwha-Banwol environmental health study.
BACKGROUND
The oral effect of chronic low-level mercury exposure is not completely understood. This study examined whether mercury exposure is associated with periodontitis.


METHODS
This study cross-sectionally surveyed 1,328 residents (598 males and 730 females) from the prospective Shiwha and Banwol cohort in Korea from July 2005 to August 2006 at baseline. Two dentists assessed periodontitis, an outcome, using the Community Periodontal Index (CPI): CPI 3 or 4 and CPI 0 to 2 were classified as periodontitis and non-periodontitis, respectively. The hair mercury level, the predictor, was analyzed. The mercury level was categorized according to the reference dose of the Environmental Protection Agency of the United States: normal = <1 ppm and high = > or =1 ppm. Age, gender, economic status, smoking, frequency of daily toothbrushing, diabetes mellitus, hyperlipidemia, and obesity were assessed as confounders. Logistic regression analysis was used to evaluate the adjusted association. Subgroup analyses for gender were also performed.


RESULTS
Mercury exposure was independently associated with periodontitis (odds ratio = 3.17). Males with high mercury levels had a 50.0% higher probability of having periodontitis than females with normal mercury levels. Of them, the interaction effect between the body burden of mercury and gender was 39.0%. The odds ratio between periodontitis and high mercury levels was higher for males than females (95% confidence interval: 0.99 to 2.23 versus 0.59 to 1.26, respectively).


CONCLUSIONS
These results suggest that mercury exposure had an independent association with periodontitis. High body-burden mercury in males might be a contributory factor linked with periodontitis.
Han
Dong-Hun
DH
Department of Preventive and Community Dentistry, School of Dentistry, Pusan National University, Busan, Korea.
Lim
Sin-Ye
SY
Sun
Bo-Cheng
BC
Janket
Sok-Ja
SJ
Kim
Jin-Bom
JB
Paik
Dai-Il
DI
Paek
Domyung
D
Kim
Hyun-Duck
HD
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001822:Body Burden; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D004781:Environmental Exposure; D005260:Female; D006197:Hair / Q000737:chemistry; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology; D007723:Korea / Q000453:epidemiology; D008297:Male; D008628:Mercury / Q000009:adverse effects* / Q000032:analysis; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D010512:Periodontal Index; D010518:Periodontitis / Q000453:epidemiology*; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D012923:Social Class; D014099:Toothbrushing / Q000706:statistics & numerical data; D055815:Young Adult
D008628:Mercury