Varnish: A New Vehicle to Increase Xylitol Release in Saliva

Objective: This study evaluated the kinetics of xylitol in saliva along time after application of varnishes containing 10% and 20% xylitol. Methods: First, 15 bovine enamel blocks (8X4 mm) were randomly allocated to 3 varnish groups (n=5/group), as follows: 10% xylitol, 20% xylitol or no xylitol (control). After application of 4mg of varnish, blocks were immersed in 500 µL of artificial saliva. Saliva samples were collected at different times after application (1, 8, 12, 16, 24, 48 and 72h) and xylitol concentrations were analyzed colorimetrically. Second, a cross-sectional in vivo study was performed. At different days, each one of 3 varnishes was applied on the buccal surface of incisors teeth of 10 volunteers. Saliva samples were collected after 5 min, 10 min, 15 min, 30 min, 1h, 1h30 min, 2h, 4h and 8h following varnish application. Data were analyzed by t test (in vitro) and two-way repeated-measures ANOVA (in vivo) (p<0.05). Results: (In vitro) - Xylitol concentrations in artificial saliva were negligible for the control group. Significantly higher xylitol concentrations were released in saliva by the 20% varnish up to 8 h after application. However, from then on, xylitol concentrations released by the 10% varnish were significantly higher. (In vivo) – Xylitol concentrations in saliva were significantly higher when both xylitol varnishes were used, when compared to placebo. The 20% xylitol varnish led to significantly higher xylitol concentrations in saliva when compared to its 10% counterpart only at 5 min following application. For both xylitol varnishes, significantly higher salivary xylitol values in respect to baseline levels were seen up to 30 min after application, but the values were still 3-4 times higher up to 90 min upon application. Conclusions: Xylitol varnish can be regarded as a promising vehicle for increasing xylitol release along time. Sponsors: FAPESP, CNPq, and DANISCO/Brazil.