In vitro and in vivo studies on salifluor/PVM/MA copolymer/NaF combination as an antiplaque agent.

Salifluor (5-n-octanoyl-3'-trifluoromethyl-salicylanilide), a broad spectrum antimicrobial agent, was investigated for its ability to inhibit dental plaque formation. A combination of salifluor with PVM/MA copolymer and NaF was optimized for its antiplaque effect in mouthrinse and dentifrice formulations based on a series of both laboratory and clinical studies. It was found that salifluor, a highly hydrophobic compound, could not be adequately solubilized with the conventional amount of sodium lauryl sulfate (SLS), the most commonly used anionic surfactant in oral hygiene products. However, it was possible to prepare stable mouthrinse formulations using a mixed surfactant system containing both anionic and nonionic surfactants. The most suitable mixture was found to be a combination of SLS, Pluronic and Tauranol in a proportion of 1:1:1. This combination provided adequate stability and high antimicrobial activity as determined by in vitro microbiological tests. Addition of a PVM/MA copolymer to the formulation improved the adsorption and retention of salifluor on stimulated tooth surfaces in vitro (saliva coated hydroxyapatite disks) by almost two-fold and also increased the antiplaque efficacy in both laboratory and human clinical studies. It was also found that a non fluoride dentifrice containing a combination of salifluor and PVM/MA copolymer with a dicalcium phosphate dihydrate abrasive, was highly effective in reducing smooth surface and fissure caries in rats. The results of the present studies demonstrated that salifluor is an effective antiplaque agent in mouthrinse and dentifrice when carefully formulated to maximize its delivery and bioavailability on oral surfaces. They also illustrated the difficulties encountered in exploiting the antimicrobial efficacy of highly hydrophobic, nonionic antimicrobial agents such as salifluor in commonly used oral hygiene vehicles.

Antiplaque effects of dentifrices containing triclosan/copolymer/NaF system versus triclosan dentifrices without the copolymer.

A dentifrice containing triclosan/PVM/MA, Colgate Gum Protection Formula Toothpaste (GPF), was found to be highly effective against oral bacteria with minimal inhibitory concentration ranging from 0.3 to 5.35 micrograms/ml. A variety of in vitro model systems simulating oral environment were used to compare dentifrices containing triclosan/PVM/MA versus the dentifrices containing triclosan without PVM/MA, such as Crest Gum Health Toothpaste (CGH) and Neo-Mentadent P Toothpaste (N-MP). The uptake of triclosan on saliva-coated hydroxyapatite (HA) disks and buccal epithelial cells was significantly higher from the GPF versus the other dentifrices. Uptake on HA disks was 132 micrograms/disk versus 11 micrograms/disk from CGH; on buccal epithelial cells the uptake was 59 micrograms/2 x 10(5) cells with GPF versus 30.0 micrograms with CGH per same number of cells. The retained triclosan on the surfaces provided a sustained and higher antibacterial effect up to 4 hours post-treatment with GPF, but not with N-MP and CGH. In dynamic plaque model systems such as the chemostat or the controlled saliva flow system, GPF was significantly (P = 0.05) more effective than N-MP or CGH in reducing plaque thickness, protein and carbohydrate contents of plaque films. Collectively, the results of these microbiological and biochemical investigations indicate that the GPF has the potential to provide superior clinical efficacy versus the dentifrices without the copolymer.