Background
discolored teeth, DH, tooth, Dentin hypersensitivity
DENTAL CARIES, DENTIN HYPERSENSITIVITY
Dentin hypersensitivity (DH) is caused by the exposure of dentin because of defection of enamel or cementum [To solve these problems, we focused on the powder jet deposition (PJD) technique [
Photographs of PJD-UNIT (a) main body and handpiece of PJD-UNIT, (b) application of spraying on the tooth, (c) after application of PJD-UNIT (after injection test)In addition, we confirmed the safety of soft and hard tissues in Beagle dogs (approval number 19MedA-1 6: Committee of the Tohoku University Environmental & Safety Committee) based on consultation with Japanese regulatory authorities (e.g., the Pharmaceutical and Medical Device Agency). Based on these results, we obtained certification for the implementation of clinical trials. Therefore, we previously conducted an exploratory clinical trial to determine the effectiveness and safety of the HAP layer formed by the PJD-UNIT in treatment of dental caries, DH, and discolored teeth [Based on the results of preclinical studies and exploratory clinical study, the effectiveness and safety of the PJD-UNIT for DH were demonstrated. Nevertheless, as the exploratory clinical trial was a single-arm trial with a limited number of subjects, both the clinical effectiveness and safety were insufficient in terms of obtaining pharmaceutical approval. As mentioned above, the PJD-UNIT may have advantages in DH treatment over conventional methods because better sealing of dentinal tubules with high biocompatible HAP can be achieved [