An In Vitro Comparison of Clinpro™ XT and Duraphat Varnish for Protecting Teeth from Discoloration during Orthodontic Treatment

Abstract

Objective. During orthodontic treatment, a higher caries risk has been reported, so fluorides and other remineralizing compounds have been proposed. Currently, fluoride varnish is commonly available in conventional and light-curable forms. This in vitro study was performed to evaluate the effectiveness of two different materials, Clinpro™ XT (light-curable forms) and Duraphat (conventional forms) varnish, whose main active principle according to their manufacturers is fluoride in preventing tooth discoloration during orthodontic treatment with appliances attached with metal brackets or resin. Materials and Methods. This study included 120 premolars free of white spot lesions and caries that were randomly divided into the following six groups (n = 20): resin control (RCTR), resin Clinpro (RC), resin Duraphat (RD), bracket control (BCTR), bracket Clinpro (BC), and bracket Duraphat (BD). All the samples were exposed to 180 ml of coffee (4 times × 5 min/day) for 7 or 28 days. When not immersed in coffee, the teeth were stored in artificial saliva, which was replaced every day. The lightness ( $L^{\ast }$ ), red/green axis ( $a^{\ast }$ ), and yellow/blue axis ( $b^{\ast }$ ) values were recorded with a dental spectrophotometer (Easy shade Advance 4.0) on days 0 (baseline), 7, and 28. The color difference ( $\Delta E^{\ast }$ ) on days 7 and 28 was also calculated. Results. The data were statistically analyzed using one-way ANOVA and Bonferroni’s test (α = 0.05). Significant differences were observed between the $\Delta E^{\ast }$ , $L^{\ast }$ , $a^{\ast }$ , and $b^{\ast }$ values of the Clinpro™ XT and Duraphat groups and those of the control groups after 7 and 28 days regardless of the attachment type ( $P$  < 0.001). On day 7, no significant differences were observed between the Clinpro™ XT and Duraphat groups, whereas on day 28, the Duraphat groups with metal and resin attachments exhibited significant differences from the Clinpro™ XT groups ( $P$  < 0.001). No significant differences correlated to the attachment type were observed throughout the discoloration procedure. Conclusions. The application of fluoride varnish during orthodontic treatment can significantly reduce tooth discoloration caused by the staining solution. Clinpro™ XT varnish showed a longer period of efficacy in protecting teeth from discoloration than Duraphat. No differences in tooth discoloration were observed between the groups with fixed and clear appliances.