Hyaluronic acid (HA) is found in connective tissue and participates in wound healing. We investigated the efficacy of a HA gel (2% hyaluronic acid; 1% antioxidants, coenzyme Q10 and vitamin E; and 5% benzocaine) on healing of palatal wounds in rats. We established two groups of rats: a control group treated with vehicle and an HA group treated with HA gel. The control group was divided into five subgroups and the HA group was divided into four subgroups according to the day on which animals were sacrificed. Wounds were created by elevating 5 mm diameter full thickness flaps. Healed and unhealed wound areas were measured using photographs. Transforming growth factor (TGF)-β, insulin-like growth factor (IGF), and collagen I and III expressions were determined using immunohistochemistry. The number of fibroblasts increased and inflammatory cells decreased from day 0 to 21 in both groups. The HA group exhibited more fibroblasts by day 7 compared to controls; (TGF)-β and IGF levels were similar between HA and control groups. HA groups exhibited fewer inflammatory cells than controls on days 3 and 7. We found significant differences in TGF-β and IGF levels among HA groups between days 3 and 21, and among control groups between days 0 and 21. Collagen I and III levels were greater for the day 3 HA group compared to controls. We observed improved wound healing in HA treated rats within 7 days.

Aim: In this study, we aimed to evaluate the possible changes in hypoxia markers and bacterial compo-nents in patients with periodontitis and bruxism. Methods: Four study groups were created: 20 healthy individuals without bruxism (Group 1), 20 periodontitis patients without bruxism (Group 2), 20 healthy individuals with bruxism (Group 3), and 20 periodontitis patients with bruxism (Group 4). Plaque index, gingival index, and clinical attach-ment levels were recorded and gingival crevicular fluid (GCF) and dental plaque samples were taken. The GCF vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-alpha (HIF-1α) levels were determined. Subgingival plaque samples were evaluated for 5 bacterial species (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fu¬sobacterium nucleatum). Results: Compared to patients with periodontitis, plaque index, gingival index, and clinical attachment levels were significantly lower in healthy individuals. The GCF and serum levels of VEGF and HIF-1α were similar (p>0.05). The A. actinomycetemcomitans, T. denticola, and F. nucleatum counts did not differ significantly between the study groups (p>0.05). P. gingivalis counts were lowest in Group 1 and increased with both periodontitis and bruxism. T. forsythia counts were higher in Group 1 and Group 2 than in Group 3 and Group 4. The levels in Group 1 were lower than those in Group 2. Conclusion: Individuals with and without bruxism were found to be similar in terms of hypoxia in periodontal health and disease. However, one of the major oral pathogens, P. gingivalis, is af¬fected by the presence of bruxism, regardless of periodontitis.