Development of delivery systems for treatment of dentin hypersensitivity

The study aimed to evaluate the penetraion depht and effects of different carrier systems (Chitosan, Carbomer and HPMC) in combination with sodium flouride (NaF), Clinpro white varnish alone and combination of all with Nd:YAG laser (1.5 W,10 Hz, 60 sn) on open dentinal tubules in vitro. Dentin specimens were collected from freshly extracted human impacted third molar teeth. The dentin samples derived from root surfaces of the teeth were divided into 22 groups (n=15). Changes in dentin surfaces and tubules were evaluated using scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). The results of SEM images were statistically analyzed with Kruskall Wallis and Dunn multi-comparison test, the penetration depths of the gels were statistically analyzed with one-way ANOVA and LDS tests. In conclussion, it was observed that all test products resulted in an occlusal layer on the dentin surface and significantly reduced the diameter of dentinal tubules after treatment in comparison with the control group (P<0.05). NaF- Chitosan combinated group represented the most profound effect in obturating dentinal tubules diameter. Furthermore, the number of open tubules was decreased compared to those in control group. In laser therapy group there is no statistically significant change in penetration depth, however combination of clinpro white varnish and laser increased the occlusion of dentinal tubules. The highest penetration depth was determined in clinpro white varnish group (P<0.05). Due to prolonged retantion of NaF on the dentinal surfaces and decreased dentinal permability, these carrier systems can be suggested as promising in the treatment of DH.