Effect of Nano-hydroxyapatite and Low-level Laser Therapy on Dentin Hypersensitivity Control: Clinical, Randomized, Double-blind, Placebo-controlled Study

GLASER received the laser application using the infrared light spectrum with wavelength of 808 nm with its active AsGaAl medium in two points of the vestibular face of the hypersensitive teeth. It was applied at each point 60 J / cm², for 16 seconds. The laser was applied in 2 sessions with a time interval of 24 hours. GLASERnHAP first received laser application and then the application of nanohydroxyapatite according to the manufacturer's recommendations. Before initiating laser therapy, the equipment was calibrated with a tester (MMOptics Ltda®, São Carlos, SP, Brazil).

The GnHAP volunteers were submitted to the application of Desensibilize Nano P on the vestibular surfaces of hypersensitive teeth with the aid of a Microbrush applicator (Microbrush, 3M ESPE, São Paulo, Brazil) for 10 minutes. Then, a rubber cup (Unid Microdont, São Paulo, SP, Brazil) mounted on a low speed handpiece (Dabi Atlante, Ribeirão Preto, SO, Brazil) was used to scrub the desensitizing gel on teeth for 20 seconds in each tooth, according to the manufacturer's specifications. GPLACEBO followed the same protocol used in Gn-HAP. In addition to the desensitization treatment, all GnHAP and GPLACEBO volunteers received the positioning of the laser tip to mimic the light emission produced in GLASER and GLASERnHAP. The noise emitted by the laser device during mimicry was simulated through the sound reproduction of a smartphone application (HD Voice Recorder - iPhone 6s, Apple®, Cupertino, California, USA).