Evaluation of Streptococcus mutans Colonization and Oral Hygiene Status in Primary Molars Restored with Two Different Crowns: A Randomized Clinical Trial

Abstract

Background: Full-coverage restorations are commonly employed choice of treatment in treating multisurface carious lesions in primary teeth. Aim: To assess the amount of Streptococcus mutans (S. mutans) colonization and oral hygiene status in deciduous molars restored with preformed zirconia and stainless steel crowns (SSC). Materials and methods: A total of 21 children aged between 4 and 7 years with bilateral carious primary molars were randomly divided into two groups of zirconia and SSC. Plaque collection was done using sterile swabs at baseline and 1-month intervals. S. mutans was cultured on mitis salivarius-bacitracin agar (MSBA). The microorganisms were then counted and expressed as colony-forming units. The plaque and gingival indices were recorded during the follow-up visits. All data were tabulated and subjected to statistical analysis, with the level of significance set at 5%. Results: A total of 21 children with 42 teeth were randomized into group I—SSC and group II—zirconia crowns using the split-mouth technique, respectively. The zirconia group showed a statistically significant reduction in the adhesion of S. mutans (p < 0.001). On comparing the plaque and gingival indices between the groups, plaque index (PI) and gingival index (GI) scores were significantly low in the zirconia group as compared with the SSC, with a mean difference of 0.08 at 3 months in group II (p < 0.001). Conclusion: Streptococcus mutans (S. mutans) adhesion to zirconia crowns was significantly less when compared with SSC, with better gingival health and oral hygiene.