We used a polymicrobial (PM) biofilm model to examine associations of bacterial adhesiveness with surface characteristics of various dental materials. Four types of dental materials (apatite pellet, zirconia, ceramic, and composite resin) with rough and mirror surfaces were used. Surface roughness, surface free energy, zeta potential, and colony-forming units (CFUs) of the biofilm formations were measured. Biofilms were cultured for 24 h under anaerobic conditions, plated onto blood agar medium, and anaerobically cultured for 4 days. After culturing, CFU per mm 2 was calculated, and samples were observed under a scanning electron microscope. Means and standard deviations of the experimental data were estimated, and one-way ANOVA and Tukey multiple comparison assays were performed. Pearson correlation coefficients were obtained for the CFU and surface characteristics. Surface roughness and surface free energy appeared to affect generation of PM biofilms on oral materials, and zeta potential was involved in generation of PM biofilms on mirrorground oral materials.

Background: Silane coupling agents are used as a bonding agent between ceramics and resins in dentistry. The effectiveness of these agents is often enhanced by the addition of acid or by heat treatment. Objective: This study aimed to evaluate, the clinical characteristics, TBS (tensile bond strength) and water resistance of eight commercial ceramic primers (seven silane coupling agents and one alumina zirconia primer). Method: Glass plates were used as the adherent. The TBS of the resin composite and the wettability of the resin monomer to glass surfaces treated with ceramic primers was investigated, with 3-MPS (methacryloxypropyltrimethoxysilane) used as a control. The values obtained from the experiments were analyzed using one-way ANOVA followed by Tukey's multiple comparison tests (p < 0.05). Results: No significant differences in TBS were observed between the commercial products and MPS, except for the alumina zirconia primer. However, four products (three of the seven agents and the alumina zirconia primer) exhibited significantly lower TBS values after application of thermal stress when compared with those stored in water (p < 0.05). All but one of the eight primers displayed significantly higher contact angles between the treated glass and the resin monomer when compared with MPS (p < 0.05). These results suggest that some commercial ceramic primers may contribute to increased strength and durability.

we surveyed new patients examined in the Department of Operative Dentistry between April 1, 2019 and March 31, 2020. The following six items were extracted from the patients' electronic dental records: referral (yes/no) , sex, age, residence, chief complaint, and site of chief complaint. Patients were subsequently divided into groups according to referral status for comparison of the other items. To identify factors associated with referrals, we performed logistic regression analysis with referral as the dependent variable and sex, address, age, chief complaint, and site as independent variables; odds ratios and 95% confidence intervals were calculated for each variable. Odds ratios were high for age, site, chief complaint, and sex and yielded the following conclusions concerning these variables. Regarding age, most patients in the referral group were in their 40s and 50s, while most patients in the nonreferral group were in their 60s and 70s. The majority of new patients were female, while the percentage of male patients was slightly higher in the referral group than in the nonreferral group. The most common sites were the molars in both groups. The most common chief complaints in the referral group and the nonreferral group were apical periodontitis and class 2 caries, respectively. These results suggested that compared with the nonreferral group, patients in the referral group were younger, were diagnosed earlier, and visited our hospital with greater expectation of dental preservation through highquality treatment.

The events of each phase must happen in a precise and regulated manner. In this process, many factors can affect wound healing by interfering with one or more of those phases, which can cause improper or impaired tis-sue repair.One of the critical stages in healing is inflammation, in which neutrophils and macrophages are recruited to remove debris from the wound site to prevent infection.The inflammatory response consists of a variety of events characterized by immune cells, which involves the influx of leukocytes and proangiogenic molecules to the wound (1) . Interleukin (IL) -1β is required for proper wound healing in a mouse wound model (2) . IL -6, which acts as a proinflammatory cytokine, is required to stimulate intestinal epithelial proliferation in the process of mucosal wound healing (3) , and IL -6 is induced soon after injury Correspondence to：