Protection of dentin by triclosan toothpaste in a bacterial demineralisation model

The effect of the addition 0.3% triclosan to a non-fluoride and fluoride to othpaste was tested in an in vitro demineralisation model. This model compr ised bovine dentin specimens overlaid with acidogenic Streptococcus mutans suspensions in agarose at two different concentrations of cells. Before the experiments, subsurface lesions were made in the dentin specimens in a met hylcellulose gel system. In a first set of experiments, the toothpastes wer e diluted in the S. mutans suspensions at w/v dilutions of 1:100, 1:1,000, and 1:10,000, respectively. After 22 h of incubation at 37 degrees C, the s uspensions were removed and assessed for calcium, lactate and pH. In this s et of experiments, an additive protective effect of triclosan to the non-fl uoride toothpaste was found at the lowest concentration of S. mutans cells and when the toothpaste was relatively undiluted (1:100 w/v). No additive e ffect was observed to the fluoride toothpaste. In the second set of experim ents, the specimens were immersed daily for 3 min in 30% (w/v) slurries of the toothpastes before the 22-h incubations with the S. mutans suspensions. At the lowest concentration of S, mutans cells, triclosan had an additiona l protective effect to the non-fluoride and fluoride toothpaste. It is conc luded that triclosan may contribute to the protection of dentin under a mil d acid attack both when it is present in dental plaque and when it has been adsorbed to the dentin.