The effects of sugar-free chewing gums on dental plaque regrowth: a comparative study

Sugar-free chewing gum has been claimed to be a useful means of reducing dental plaque accumulation. The incorporation of additives, such as enzymes, abrasives and divalent metal ions, into gum formulations might improve their antiplaque activity, particularly at the buccal and lingual surfaces of the teeth. Objectives The aim of this study was to investigate the plaque inhibitory effects of three sugar-free chewing gums each containing lactoperoxidase (LP), micro granules of silicon dioxide (SD), and zinc gluconate (ZG). Methods The study was an observer-masked, randomized cross-over design balanced for carryover effects, involving 12 healthy volunteers in a 4-day plaque regrowth model. An additive-free (AF) gum served as positive/negative control for occlusal and smooth surfaces, respectively. On day 1, subjects received professional prophylaxis, suspended oral hygiene measures, and commenced chewing their allocated product. Gum chewing was one piece chewed for 30 min 4 times a day. On day 5, subjects were scored for disclosed plaque. Results There were no significant differences in antiplaque activity of the gums tested, neither for the smooth nor for the occlusal surfaces ( P = 0.447 and P = 0.418, respectively). Similar results were obtained for the anterior and posterior sites of smooth surfaces ( P > 0.05), and for the lower and upper sites of occlusal surfaces ( P = 0.451 and P = 0.53, respectively). Conclusions These findings suggest that the chewing gums containing LP, SD and ZG would provide no plaque inhibitory effects on smooth surfaces. The gums containing these additives, therefore, should not be recommended as adjuncts to mechanical oral hygiene.