Can clusters based on caries experience and medical status explain the distribution of overhanging dental restorations and recurrent caries? A cross-sectional study in Madinah – Saudi Arabia

BACKGROUND: Overhanging dental restorations (ODRs) and secondary caries lesions (SCLs) are of high prevalence and jeopardize the fate of the restoration. OBJECTIVES: To assess the relationship between ODRs, SCLs and certain caries contributory factors. METHODS: A total of 502 radiographic records of dental patients with proximal fillings (mean age 38 ± 13 years, 50% females) were screened for ODRs and SCLs. Descriptive and inferential statistics were used. In addition, two-step cluster analysis was performed in an attempt to explain trends in ODR and SCL distribution. A p value of ≤ 0.05 was considered statistically significant. RESULTS: More than 30% of the individuals had ODRs and SCLs. No differences between genders were observed (p > 0.05). Individuals with medical conditions had more ODRs than those without (49% vs. 34%, p ≤ 0.05), while those with high caries experience had more SCLs (49%, p ≤ 0.05). The cluster analysis grouped the participants in five clusters, with the cluster involving individuals with no medical conditions and low caries experience demonstrating the lowest prevalence of ODRs and SCLs. CONCLUSIONS: Within the study limits, more than one third of the sample of dental patients had ODRs and SCLs. The medical condition was associated with ODRs, while the past caries experience was associated with SCLs.