The relationship between different types of caries and periodontal disease severity in middle-aged and elderly people: findings from the 4th National Oral Health Survey of China

Abstract Background: The relationship between dental caries and periodontal disease is still controversial. The objective of this study is to explore the relationship between different types of caries and periodontal disease severity in middle-aged and elderly people in China.Methods: The study population consisted of 4,387 middle-aged and 3,225 elderly subjects. Caries were divided into the following three types: type A, crown caries; type B, lesions involving both the crown and root, representing a mixed type; and type C, root caries. These three types together represent the overall caries situation, which we call type ABC. Caries were quantitated by decayed and filled teeth (DFT index). Periodontitis was evaluated by clinical attachment loss.Results: Middle-aged people with periodontitis had a significant association with DFT of type ABC (OR: 1.09, 95% CI: 1.06‐1.11), type A (OR: 1.05, 95% CI: 1.02‐1.08), type B (OR: 1.20, 95% CI: 1.16-1.28) and type C (OR: 1.36, 95% CI: 1.15-1.60). Elderly people with periodontitis had a significant association with DFT of type ABC (OR: 1.05, 95% CI: 1.03-1.07), type B (OR: 1.07, 95% CI: 1.05-1.10) and type C (OR: 1.30, 95% CI: 1.19-1.42) but not type A.Conclusions: Different types of caries in middle-aged people and overall caries and caries types involving the root surface in elderly people were significantly associated with periodontal disease severity.