Comparison of antibacterial activity of glass-ionomer cement and amalgam in class two restorations by Streptococcus mutans count analysis at fixed intervals: an in vivo study.

AIM The purpose of the present study was to determine the influence of glass ionomer cement and amalgam restoration on the level of Streptococcus mutans in the interproximal plaque at periodic intervals and also to compare these values. MATERIALS AND METHODS Seventeen adult patients having two proximal carious lesions on any quadrant of the jaw (either opposing or contralateral) were selected for this study. Carious lesions were diagnosed clinically and from bitewing radiographs. Of the two carious lesions, one was restored with glass ionomer cermet cement and another with amalgam. Plaque samples were collected from interproximal areas before and at 1 month and 3 months post-treatment in a test tube containing 5 ml of modified Stuart's liquid transport fluid. Identification of organisms in the colony was done after Gram staining. RESULTS Comparison of values before restoration and after restoration at 1 month interval showed a statistically significant decrease (p<0.001). Similarly, comparison of values before and after restorations at 3 months also showed statistically significant decrease (p<0.02). But comparison of restorations of 1 and 3 months intervals showed no statistical significant difference (p>0.05). CONCLUSION Glass ionomer restorations have definite advantage over the amalgam, as the tunnel preparation is more conservative and fluoride release from the glass ionomer inhibits the growth of S. mutans in the plaque. CLINICAL SIGNIFICANCE Glass ionomer cement should be preferred over amalgam in conservatively prepared restorations as it reduces the microbial activities due to fluoride release.