Immediate hyperbaric oxygen after tooth extraction ameliorates bisphosphonate-related osteonecrotic lesion in rats.

BACKGROUND: This study aims to assess whether hyperbaric oxygen (HBO) applied immediately after tooth extraction could ameliorate medication-related osteonecrosis of the jaw in rats. METHODS: To evaluate whether osteonecrosis could be successfully induced, healing of extraction maxillary molars was examined in 40 female Sprague Dawley rats received zoledronic acid (7.5 µg/kg) plus dexamethasone (1 mg/kg). Rats were divided into four groups, receiving zero, two, four, or seven injection(s) for 7 days, respectively. Effect of HBO, pressurized to 2.5 atmospheres absolute (ATA) at rate of 0.15 ATA/min with 100% oxygen for 90 minutes, applied immediately after tooth extraction, on the development of osteonecrosis was evaluated. Lesions among groups were compared by size of ulceration, exact area (mm2 ) or relative area (%), and by histology. RESULTS: Unhealed ridge was observed in all nine rats in four and seven injection groups, but none of 10 rats in the control (non-injection) group. Immediate HBO significantly reduced the lesions in rats that received four injections, regardless of the distribution and the total/relative areas of lesions (P <0.01). Histological findings showed the lesions were uncovered epithelium and severe tissue inflammation. CONCLUSION: This is the first in vivo study demonstrating the HBO applied immediately after tooth extraction effectively decreases the development of medication-related osteonecrosis.

Therapeutic applications of resveratrol and its derivatives on periodontitis.

Periodontitis is an inflammatory disease of the supporting tissues of the teeth induced by periodontopathic bacteria that results in the progressive destruction of periodontal tissues. Treatment of periodontitis is painful and time-consuming. Recently, herbal medicines have been considered for use in treating inflammation-related diseases, including periodontitis. Resveratrol and its derivative 2,3,5,4'-tetrahydroxystilbene-2-O-ß-glucoside (THSG), a polyphenol extracted from Polygonum multiflorum, have anti-inflammatory properties and other medical benefits. Here, we highlight the importance of resveratrol and its glycosylated derivative as possible complementary treatments for periodontitis and their potential for development as innovative therapeutic strategies. In addition, we present evidence and discuss the mechanisms of action of resveratrol and THSG on periodontitis, focusing on Porphyromonas gingivalis-induced inflammatory responses in human gingival fibroblasts and animal modeling of ligature-induced periodontitis. We also illuminate the signal transduction pathways and the cytokines involved.

Carvacrol Ameliorates Ligation-Induced Periodontitis in Rats.

BACKGROUND: This study aims to evaluate the ameliorative effect of carvacrol, an anti-inflammatory monoterpenoid phenol and a major component of Plectranthus amboinicus, on periodontal damage in an experimental rat model of periodontitis. METHODS: Forty Sprague-Dawley rats were divided into ligation (Lig), non-ligation (n-Lig), and two ligation plus carvacrol (Lig+C) groups. Carvacrol (17.5 or 35.0 mg/kg body weight/day) was administered intragastrically from 1 day before ligation. On day 8, dental alveolar bone loss and gingival inflammation in periodontal specimens were examined by dental radiography, microcomputed tomography, and histology. Expressions of tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, and inducible nitric oxide synthase messenger (m)RNAs, and levels of matrix metalloproteinase (MMP)-2 and MMP-9 in gingiva were examined by reverse transcription-polymerase chain reaction and zymography. RESULTS: Dental radiography revealed periodontal bone-supporting ratios in Lig and Lig+C groups were lower than the n-Lig group, with Lig group ratios being lowest. Compared with the n-Lig group, the cemento-enamel junction-bone distance was significantly longer in Lig and Lig+C groups, with Lig+C groups showing shorter distances regardless of radiographic methods used. Histology and histometry showed less inflammatory area and stronger connective tissue attachment in Lig+C groups than in the Lig group. Cytokine/mediator mRNA expression and MMP-9 levels were reduced in the Lig+C groups. CONCLUSIONS: Carvacrol reduced tissue damage and bone loss caused by ligation-induced periodontitis. The present results indicate that carvacrol might reduce tissue destruction by downregulating expression of proinflammatory mediators and MMP-9.