The influence of removable partial dentures on the level of Streptococcus mutans in saliva

Abstract

S everal clinical studies have investigated the incidence of caries and plaque accumulation in patients with removable partial dentures (RPDs). In two long-term studies, caries and plaque accumulation on abutment teeth were found to be high.‘,* In two other studies, plaque was noted particularly on tooth surfaces associated with a denture clasp or the denture base.3p4 Twice daily toothbrushing, reportedly, did not fully offset the increase in plaque accumulation.3 However, patients with RPDs, who received a program of intensive and reinforced oral hygiene instruction, were found to have low plaque scores and minimal caries incidence.5j6 Similarly, the placement of fixed orthodontic appliances has been associated with increased plaque retention.’ Several studies have also reported proliferation of Streptococcus mutans, the microorganism most associated with caries activity,&” in patients wearing orthodontic appliances. ‘*-I4 The increased proportion of S. mutans in such patients is perhaps because this microorganism colonizes retentive tooth sites more readily than nonretentive sites.15 Furthermore, S. mutans has been noted to colonize the acrylic resin of complete dentures.16 Given the association of S. nzutans with caries incidence, the present study was done to establish whether a change in the level of this microorganism also occurs in patients who receive RPDs. Thus salivary concentrations of S. mutans were analyzed in partially edentulous patients both before and after insertion of their dentures.