Background & Aim: People in some areas of Ramsar, a city in northern Iran, receive an average whole body dose, that is about 5 times higher than the normal background radiation level. The high background radiation in these areas of Ramsar is primarily due to the presence of very high amounts of 226 Ra and it’s decay products (like radon), which are brought to the earth’s surface by hot springs. 226 Ra is chemically similar to Ca and tends to accumulate in bones and teeth. The object of this study was to evaluate dental & periodontal health status of the people residing in the high background radiation areas (HBRAs) of Ramsar, compared to a control region (with much lower level of natural radiation), in this city. Method & Materials: This analytic case-control study was accomplished on 322 people aged 15-75, residing in Talesh Mahaleh & Chaparsar, as the case group and Talesh Mahaleh of Katalom, as the control group. The method of collecting the data, was all-counting. CPI, DMFT indices were considered to evaluate dental & periodontal health. SPSS11 and SAS 8 softwares were used for the data analysis.
Results: Considering the highest CPI codes, there was a significant difference between two groups (p<0.05): 1.1% and 6.9% of the subjects had normal periodontium (code 0), 9.6% and 13.9% of the subjects had bleeding on probing (code 1), 50.6% and 49.3% of the subjects had subgingival calculus (code 2), 35.4% and 25.7% of the subjects had shallow pockets (code 3), 3.4% and 4.2% of the subjects had deep pockets (code 4), in HBRAs and the control region, respectively. Concerning codes 3 & 4 together, as the major periodontal disease level, the percentages of this level were 38.8% and 29.9% in the case and control groups, respectively. There was a significant difference in DMFT, between HBRAs and the control group: mean D was 5.77±3.47 and 4.70±3.72 (p<0.05), mean F was 1.19±2.09 and 0.51±1.37 (p<0.01), and mean DMFT was 13.13±6.10 and 10.83±6.61 (p<0.01), in two regions, respectively. There was no significant difference in mean M between the two groups (p>0.05).
Conclusion: Considering the DMFT and CPI scores, we can conclude that the condition of dental and periodontal health in people residing in HBRAs of Ramsar is different and poorer from the control area. These results can’t be explained by the differences of gender, age group, literacy, smoking, frequency of brushing, dental attendance and the kind of drinking water, between two regions. It seems that being exposed to high levels of natural radiation can contribute to the findings.
J Dent Sch 2006 24(1): 17