Oral cleansing effect of sugar-free chewing gum with sodium hexametaphosphate and xylitol

To investigate the effect of sugar-free gum (SFG) with xylitol and sodium hexametaphosphate (SHMP) on oral cleansing by in vitro tests and a human clinical trial.

Hydroxyapatite (HA) discs were pre-treated with SHMP and evaluated for inhibition of stain formation caused by infusion of black tea in vitro. Subsequently, the effect of SFG formulated with different levels of SHMP was determined using a laboratory chewing apparatus to establish effective dosage of SHMP. Stain levels in both tests were assessed by colorimetry to determine L*, a*, b* values. Finally, a 12-week randomized, single blind, parallel arm human clinical study was performed to test effects of xylitol gum with SHMP on clinical indices of stain (Lobene Stain Index) and plaque (Plaque Index). 195 subjects were enrolled, with 181 subjects completing the trial.

In vitro pre-treatment of HA discs with SHMP significantly inhibited tea-induced stain. Results from the chewing machine study showed that gums with SHMP significantly inhibited stain formation at 7 and 14 days, with a minimum effective level of 16.5 mg. The clinical study showed that SFG with 50% xylitol and 0.5% SHMP significantly inhibited plaque after 12 weeks compared with baseline and no-gum control (P< 0.05). The test gum also demonstrated a significant reduction of stain formation compared with baseline, no-gum control and commercial gum after 12 weeks (P< 0.05), reducing surface stain by 34% compared with baseline (P< 0.05). It was concluded that sugar-free gum containing xylitol and a low level of SHMP can provide an effective oral cleansing benefit, adjunctive to regular toothbrushing.

In addition to its well-recognized anticariogenic benefit, sugar-free gum formulated with xylitol and a low level of SHMP can also provide an effective oral cleansing benefit by helping control extrinsic tooth stain and plaque accumulation.