Dental caries in first and second molars among adolescents: a comparative cross-sectional study

Dental caries in permanent molars is common among adolescents, however, evidence directly comparing the extent, level, severity, and patterns of caries between first and second permanent molars are limited. Therefore, this study aimed to compare caries experience between first and second permanent molars among adolescents and to evaluate caries-related risk factors. A cross-sectional study was performed on 80 adolescents aged 12–19 years. Participants were examined to assess caries extent, site, level, and distribution in first and second molars. In addition, demographic data, oral hygiene habits, and dental care practices data was collected. Statistical analyses, including chi-square tests and multinomial logistic regression, were used to examine the associations between the collected data and caries in both molars. The findings demonstrated significantly higher caries level in first molars compared to second molars (P< .05). Factors such as frequency of brushing, history of toothache, and visits to the dentist were associated with caries levels and classification (P< .05). The first molars were more frequently affected by Class 1 and 2 caries, while lower second molars were more likely to develop Class 1 caries (P< .05). Multinomial regression identified that presence of a history of toothache significantly increased the odds of having more caries in the first molars compared to the second molars (OR = 8.3E7, P< .001), more class 2 caries in comparison to Class 1 caries (OR = 2.99E7, P< .001), and more upper and lower carious lesions in comparisons to having lower lesions only (OR = 6.0E7, P< .001). First molars are more susceptible to caries than second permanent molar among adolescents. History of toothache is associated with more caries in first molars, Class 2 caries, and having both upper and lower lesions. This highlights the importance of caries prevention measures and good oral hygiene in preventing caries in both first and second molars. Thus, targeted caries preventive strategies, such as fluoride treatments and sealants, are advised to address the higher caries risk in permanent molars. Further longitudinal studies are recommended to track caries progression in molars and the effectiveness of preventive strategies over time, particularly in lower-income adolescents.