The-Effect of Single-Application of a Novel Varnish on Dentin-Hypersensitivity: a-Pilot-Study

Objectives: This study aimed to determine the effect of the newly formed Rennou® (Theobromine, calcium(Ca) and phosphate(P)) varnishes on dentin permeability in human extracted teeth.
Methods: Twelve extracted human third molars collected. The teeth stored in 0.1% thymol before the start of the study.The teeth were partially embedded in acrylic discs and ground flat until the dentin was exposed. The dentin surface was etched with 37% orthophosphoric acid for 30 s to simulate open tubules and followed by washing with water to simulate open tubules that cause dentin hipersensitivity, rinsed in water for 25s, and dried with absorbent paper. 12 dentin samples was equally allocated into four groups, classified as follows: Group 1: 3% Rennou® varnish (Theodent LLC, New Orleans, La., USA) , Group 2: 5% NaF containing varnish ,Group 3: 5% NaF varnish + 3% Rennou® varnish, Group 4: Rosin. The varnishes applied with a microbrush to the dentin surface and kept for 10 minutes before cleaning.The varnishes have been removed from the tooth surface,then samples were then placed on SEM holders and got sputter-coated with a standardized gold layer of 8.0 nm Images were obtained using scanning electron microscopy (SEM). A surface assessment was performed at 2500x magnifcation.
Results: After the acid challenge, dentin surfaces treated with 3% Rennou® varnish remained with most of the tubules occluded. The 3% Rennou® group presented a deposition of a compound containing theobromine, calcium and phosphate(Ca/P). SEM analysis found mineral particles covering the dentinal surface and obliterating the tubules for the dentine samples that were treated with 5% NaF + 3%rennou® varnish. SEM images did not present tubule obliteration in samples from the rosin group.
Conclusions: The composition containing theobromine, Ca and P effectively occluded dentinal tubules and therefore exhibits a potential for reducing the discomfort caused by dentin hypersensitivity.