Anti-plaque and antibacterial effect of two toothpastes

Objectives: Aim of this double-blind, randomized, cross-over study was to compare the antiplaque and the antibacterial effect of two toothpaste formulations containing triclosan or zinc chloride. Methods: After a professional toothcleaning seventeen volunteers refrained from all oral mechanical hygiene measures for the subsequent 24 hrs (Day 0). Thereafter a plaque sample was taken from 3 teeth and analyzed for vitality of the plaque bacteria by means of the vital fluorescence technique (VF 0; in %). After assessment of this baseline value the subjects had to brush their teeth for 2 min with 1.2 ml of the allocated toothpaste containing (a) 0.2% zinc chloride or (b) 0.3% triclosan. For the following 8 hrs no oral hygiene measures were allowed. After 4 (VF 4) and after 8 hrs (VF 8) further plaque samples were analyzed for biofilm vitality as described above. For the following 3 days the volunteers had to brush twice daily for two minutes with their toothpaste. On day 4, plaque index was assessed using the criteria of Quigley and Hein (Turesky modification). After a washout time of 2½ days a new test cycle was started. Results: Both toothpastes reduced the biofilm vitality significantly at VF 4 and VF 8 compared to VF 0. While the zinc chloride toothpaste obtained higher reductions (38%, 47%) than the triclosan toothpaste (35%, 34%), results for plaque index were the same in both toothpastes (0,62, respectively). Conclusion: Both toothpastes show a prolonged antibacterial effect up to 8 hours with a benefit to the zinc chloride toothpaste.