A novel treatment based on powder jet deposition technique for dentin hypersensitivity: a randomized controlled trial.

BACKGROUND: This study aimed to evaluate the efficacy and safety of dentin hypersensitivity (DH) treatment using a newly developed device based on a powder jet deposition (PJD) technique that creates a hydroxyapatite (HAP) layer on the dentin surface, thereby alleviating the hypersensitivity. The effect of the PJD treatment was compared with that of conventional treatment using Teethmate Desensitizer (TMD; calcium-phosphate containing material with TTCP (Ca4(PO4)2O) and DCPA (CaHPO4)), which has been used clinically in Japan with well-confirmed effectiveness. MATERIALS AND METHODS: A randomized controlled trial was conducted including 35 patients who had symptoms of DH in two or more quadrants. Two test teeth were selected per patient (70 teeth in total) and randomly assigned to PJD or TMD treatment. The efficacy was evaluated using the improvement rate for air and scratch pain according to the scores obtained via visual analog scale 12 weeks after treatment. The safety assessment was performed focusing on gingival index (GI) and spontaneous pain. The t-test was used to analyze the non-inferiority of PJD treatment compared to TMD treatment. RESULTS: The improvement rate of air pain was 69.0% for PJD and 69.7% for TMD. The improvement rate of scratch pain was 80.8% for PJD and 81.7% for TMD. Non-inferiority with a margin of 10% was not observed for both air and scratch pain. No change was observed in GI from baseline and the improvement rate of spontaneous pain for PJD was higher than that for TMD. CONCLUSION: Non-inferiority of PJD to TMD treatment was not observed in this study; however, it was not statistically demonstrated, and the results were thus interpreted as inconclusive. PJD did improve the DH symptoms, as did TMD. PJD's therapeutic effect was most likely attributable to the deposition of a HAP layer on the tooth surface, which would alleviate hypersensitivity for at least 12 weeks without causing severe adverse events. TRIAL REGISTRATION: UMIN-CTR. ID: UMIN000025022. date: 02/12/2016.

Usefulness of conventional glass ionomer cements in an environment of insufficient moisture exclusion.

PURPOSE: Moisture exclusion while treating dental caries can be challenging, and the glass ionomer cements (GICs) used for these procedures are susceptible to water. Few studies have examined the effects of the powder/liquid ratio (PLR) on the physical properties of GICs exposed to water. In this study, the hardness and thickness of the water-susceptible surface layer of three GICs were evaluated. METHODS: Three conventional GICs were mixed in increasing PLRs, and hardness over time was measured under conditions of no water exposure, distilled water exposure, and saliva exposure. Furthermore, the thickness of the water-susceptible layer for each GIC was determined. RESULTS: A water-susceptible layer of approximately 250 µm was evident for all GICs, and the thickness decreased with increasing PLR. GIC hardness increased with increasing PLR in conditions without water for all GIC types. Furthermore, the removal of the water-susceptible layer restored the physical properties of each GIC. CONCLUSION: Overall, the results indicate that conventional GIC restoration with the removal of the water-susceptible surface layer is a feasible strategy for treating dental caries in individuals for whom exclusion of moisture can be difficult.

Clinical Evaluation of Monolithic Zirconia Crowns: A Short-Term Pilot Report.

PURPOSE: This study aimed to prospectively evaluate the clinical performance of monolithic zirconia crowns made of yttria-stabilized tetragonal zirconia polycrystal. MATERIALS AND METHODS: A total of 26 crowns placed on premolar or molar teeth in 18 patients were evaluated at the time of crown placement and at 2 weeks, 6 months, 1 year, and 2 years after placement. RESULTS: Twenty-five crowns rated as satisfactory according to the California Dental Association quality evaluation system. Most of the abutment and antagonist teeth showed good periodontal condition. An enamel cracking occurred on one antagonist tooth 1 year after placement. CONCLUSION: Monolithic zirconia crowns can be a clinically acceptable prosthetic option.

Influence of maxillary obturator prostheses on facial morphology in patients with unilateral maxillary defects.

STATEMENT OF PROBLEM: Facial asymmetry is prominent with individuals with unilateral bone resorption and can lead to decreased quality of life. PURPOSE: The purpose of this study was to investigate the influence of maxillary obturator prostheses on facial morphology of individuals with unilateral maxillary defects by using 3-dimensional digital stereophotogrammetry. MATERIAL AND METHODS: The facial data of 8 participants with unilateral maxillary defects were acquired with a noncontact 3-dimensional digitizer, both with and without maxillary prostheses. The mid-facial plane was established by overlapping an original facial image with its mirror image. Displacement at 18 measurement points, including 7 bilateral pairs, was compared between the 2 sides, with and without the prostheses. Asymmetry indices of these 7 pairs also were calculated. Multivariate repeated-measures ANOVA was used to determine differences. RESULTS: Displacements of the lateral and inferior points at the ala of the nose were significantly greater on the defect side than on the normal side. The distances between the ideal and defect side points at the superior ala, the upper lip, and the angle of the mouth decreased significantly with the prosthesis. No significant differences were found in asymmetry indices, but the angle of the upper lip line to the mid-sagittal plane increased significantly with the prosthesis. CONCLUSIONS: The 3-dimensional analyzing method developed in this study can be useful in evaluating facial reconstruction with maxillary obturator prostheses with individuals with unilateral maxillary defects. The prostheses affect the region of the nasal ala, the upper lip, and the angles of the mouth.