Introduction : Ozone exerts various physiological and pathophysiological effects via modulation of oxidative stress levels. Ozone ultrafine-bubble water (OUFBW) is reportedly highly biocompatible with several cell types including fibroblasts and epithelial cells, and it suppresses bacterial activity. However, the underlying mechanisms, especially―those of the effect of OUFBW on wound healing remain unknown. This study aimed to clarify the mechanisms of OUFBW effect on wound healing.

  Materials and Methods : After inflicting a wound on the dorsal of mice (male, 8 weeks old ; C57BL/6J), OUFBW or OUFBW inactive was placed on the wound area every day. Tissue morphometric and histological analysis and qPCR using granulation tissue were performed.

  Results : The in vivo mouse model of wound healing revealed that wound healing was significantly accelerated in the OUFBW group upon morphometric analysis at 7 days after wounding. Furthermore, mRNA expression of the inflammatory markers, tumor necrosis factor-α (TNF-α) and interleukin 6 mRNA, was significantly downregulated, while fibroblast growth factor-2 was upregulated in granulation tissue of OUFBW mice at 7 days. Histological analysis revealed no sign of infection, acute inflammation, and abnormal healing in OUFBW mice at 7 days. However, TNF-α and collagen type Ⅳ mRNA expression was significantly upregulated at 3 hours after OUFBW administration in the early phase of wound healing.

  Conclusion : Variations in the expression levels of the aforementioned inflammatory cytokine genes may influence wound healing after OUFBW treatment. To the best of our knowledge, this study is the first to demonstrate that OUFBW enhances wound healing via modification of inflammation.

  Purpose : This study investigated the durability and optimal retentive force for patient satisfaction of mandibular single-implant overdentures (SIOD) using locator attachment.

  Materials and Methods : Twenty-one patients with mandibular complete dentures were each treated with a single symphyseal implant to retain an overdenture using locator attachments with blue or pink nylon patrices. The retentive force of the SIOD with locator was measured monthly until patrix replacement, for a period of 10 months. Patient satisfaction with retentive force was evaluated monthly on a 100-mm visual analog scale, beginning after the first month of use. On the date of patrix replacement, patients were asked how many times they inserted and removed the SIOD daily. The durability of nylon patrices was analyzed by Kaplan-Meier estimation, and correlation was evaluated using Spearman's rank correlation coefficient. The cutoff value for optimal retention was estimated with the receiver operating characteristic curve.

  Results : The median durability for both locator patrices was 6 months (blue : 5 months, pink : 7 months). There was no statistically significant difference in durability between blue and pink nylon patrices. Spearman's correlation coefficient was 0.39 (P＜0.0001) between retention and satisfaction. Retentive forces6.05 N and8.32 N had80% sensitivity with a correct classification rate＞66%, high likelihood ratio (LR)＋, and low LR－. The area under the curve was 0.69.

  Conclusions : Locator patrices had an estimated durability of6 months with sufficient retention. Retentive forces＞6-8N provided the highest level of patient satisfaction.