The Relationship between Dental Caries in Primary Teeth and Permanent First Molars in Schoolchildren Aged 8–9 Years in Wasit Governorate-Iraq

“first molar’’ has an important role at individual's dental health among the known risk factors, the experience of previous caries is of the best predictors for future caries. The aim of this study is to determine the relationship between dental caries in primary teeth and permanent first molars. The sample examined in this study consisted of 436 schoolchildren aged 8–9 years in Wasit governorate divided into control group (children with caries free in permanent first molars) and case group (children with at least caries in one permanent first molars) these case group subdivided into four groups according to the value of DMFT of the first molars. All children subjected to clinical examination to obtain information about ‘’dental caries’’ of permanent 1^st molars (DMFT) by assessment of decayed teeth, missing teeth due to caries and filling teeth according to WHO 1997. Also information obtained about dental caries prevalence and severity in primary teeth (dmft/dmfs) by assessment decayed teeth/surfaces, missing teeth/surfaces due to caries and filling teeth/surfaces according to Gruebbel 1944. The data collection started from 1/March to 20/April 2018. Data analyzed using statistics package for social science SPSS Inc, 2016 version 24 for windows and Excel 2007. The mean value of dmft in control group was (3.42 ± 2.30) while in total case group was (5.48 ± 2.25), statistical analysis showed highly significant difference in the mean value of dmft between the two groups. The mean value of dmfs in control group was (0.09 ± 0.07) while in case group was (0.15 ± 0.10), statistical analysis showed significant differences in the mean value of dmfs between the two groups also. It was concluded that caries status in ‘’primary teeth’’ can be used as a ‘’risk indicators’’ for predicting caries in ‘’permanent teeth’’.