Background This study investigated the potential effects of Injectable Platelet-Rich Fibrin (I-PRF) on root coverage of free gingival graft surgery. Material/Method A total of 40 patients with Miller class I or II gingival recession were included. The patients who participated in this study were randomly divided into 2 groups, including the control and experiment groups. The patients in the control group were treated only with free gingival graft (FGG). The patients in the experiment group were treated with free gingival graft and injected with I-PRF as a root surface biomodification agent (FGG+I-PRF). The patients were called back after 3 months, and the amount of exposed root surface was determined and compared to the preoperative findings. Results The mean initial exposed root surface was 4.7±1.49 mm for the FGG+I-PRF group, 4.1±1.07 mm for the FGG group, and 4.4±1.31 mm for all subjects. Three months after the operation, the mean root surface coverage values of the 2 groups were 3.5±1.05 and 3.9±0.78 mm in the control and experiment groups, respectively. Conclusions The findings showed that the injection of Injectable Platelet-Rich Fibrin (I-PRF) had a positive effect on root coverage in free gingival graft surgery.

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Background: The objective of this study was to investigate whether long term formaldehyde inhalation may affect periodontal membrane and alveolar bone loss leading to periodontitis. The negative effects of formaldehyde were described using vascular endothelial growth factor (VEGF), matrix metallopeptidase 2 (MMP-2) and osteonectin antibodies involved in the extracellular matrix and angiogenetic development. Materials and methods: Thirty adult Wistar albino rats were used in this study. Rats were divided into two groups: a control group (n = 15) and formaldehyde administered group (n = 15). Formaldehyde group was exposed to inhalation of 10 ppm formaldehyde 8 hours a day, 5 days a week for 5 weeks. Maxillary bone regions were dissected under anaesthesia. After fixation in 10% formaldehyde solution, tissues were passed through graded ethanol series to obtain paraffin blocks. Five-micrometre histological sections were cut with RM2265 rotary microtome stained with Masson trichrome and VEGF, MMP-2 and osteonectin antibodies for examination under Olympus BH-2 light microscopy. Results: The present study revealed that congestion in blood vessels, degeneration of collagen fibres and alveolar matrix around alveolar bone were observed to be more significant in formaldehyde group than the control group (p ≤ 0.001). Interestingly, VEGF expression in the formaldehyde group was the most significant finding between the two groups (p < 0.001). When compared inflammation, MMP-2 and osteonectin expressions were significant (p < 0.01) in the formaldehyde group. Conclusions: It was suggested that formaldehyde toxicity decreased the expression of MMP-2 and in osteoblasts as well as affecting the retention of MMP levels in tooth cavity, which is very low in collagen fibres. But, vice versa for the expression of VEGF in dilated vascular endothelial cells and osteocytes in alveolar bone. As a conclusion, formaldehyde disrupts the periodontal membrane and may cause collagen fibres degeneration by affecting the alveolar bone matrix.

Purpose To investigate the effects of allopurinol administration on osteoinductive reaction and bone development with graft material. Methods Thirty-six Wistar albino rats were divided into 3 groups. In the control group, calvarial bone defect was only created without any treatment. In the Defect + Graft group, allograft treatment was performed by forming 8 mm calvarial bone defect. In the Defect + Graft + Allopurinol group, alloplastic bone graft was placed in the calvarial bone defect and then, allopurinol (50 mg/kg/day) treatment was intraperitoneally applied for 28 days. Results Histopathological examination revealed inflammation, congestion in the vessels, and an increase in osteoclast cells in the defect area. We also observed that new osteocyte cells, increase in connective tissue fibers, and new bone trabeculae. Osteopontin expression was positive in osteoblast cells and lacunated osteocyte cells were located in the periphery of the new bone trabeculae. Osteopontin expression was also positive in osteoblasts and osteocytes cells of new bone trabeculae in the graft site. Conclusion It has been shown that allopurinol treatment in rat calvaria defects may induce osteoblastic activity, matrix development, mature bone cell formation and new bone formation when used with autogenous grafts.

Background. Tumor necrosis factor alpha (TNF-α) is an inflammatory mediator whose levels are increased in the gingival crevicular fluid and blood serum in the case of chronic periodontitis.