Subgingival calculus: where are we now? A comparative review

Objective: To critically analyse the formation, composition, ethnic variati ons and pathogenic potential of subgingival calculus in comparison with sup ragingival calculus. Data sources: Using CD-ROM and index medicus, scientific papers relating to subgingival calculus or subgingival and supragingival calculus written in the English language since 1960 were considered, with the emphasis on more recent articles. Study selection: Studies were selected for their relevance and contemporary nature re:composition and formation of dental calculus and comparisons of ethnic groups with regard to dental calculus, especially subgingival calcul us. Some similar studies were not included. Data extraction: Abstracts of studies were kept brief unless particularly i mportant to the review. Population, methodology, statistics and accurate co nclusions were used as important guides to the quality and validity of stud ies. Data synthesis: Similarities and differences between supragingival and subgingival calculus in composition and formation were shown. Different mo rphological types of subgingival calculus were demonstrated. There was evid ence for an association between calculus formation and ethnicity with regar d to supragingival and subgingival calculus, and an association between sub gingival calculus composition and ethnicity was indicated. Conclusions: An association between ethnicity and subgingival calculus form ation and composition was found. Further research into the reasons for thes e ethnic differences in dental calculus and the role of the mineral constit uents especially of subgingival calculus would be valuable. (C) 2000 Elsevi er Science Ltd. All rights reserved.