Anatomical localization of posterior superior alveolar artery: A retrospective study by cone-beam computed tomography.

BACKGROUND: Familiarity with the anatomy of the arteries in the sinus wall is essential to prevent the perforation of the sinus membrane and bleeding during dental implant surgery. OBJECTIVES: The aim of the study was to evaluate the anatomical position of the posterior superior alveolar artery (PSAA), using cone-beam computed tomography (CBCT). MATERIAL AND METHODS: A total of 245 CBCT scans met the eligibility criteria for this cross-sectional study. The vertical distance from the lower border of the artery to the lower border of the sinus floor, the diameter of the artery, and the type of artery (intrasinusoidal, intraosseous or superficial) in the first and second premolar and molar regions were measured. The data was analyzed with the t tests, the one-way analysis of variance (ANOVA) and the χ2 tests. RESULTS: The maxillary PSAA was recognized in 187 (76.3%) scans. The mean distance between the artery and the floor of the sinus was 6.87 ±3.68 mm. The mean diameter of the artery was 1.37 ±0.61 mm. The greatest mean diameter of the artery was observed in the second premolar region, and the smallest in the first molar region. As many as 63.6% of the arteries were intraosseous, 28.9% intrasinusoidal, and 7.5% superficial. CONCLUSIONS: Due to the high prevalence of the intraosseous type, in most cases of sinus lift surgery there is an increased possibility of PSAA damage. As the largest diameter of the artery was observed in the second premolar region, the possibility of severe bleeding during sinus lift surgery in this area is increased. The average distance between the artery and the floor of the sinus was approx. 7 mm. Consequently, it is recommended that the lower border of the sinus access window should be as high as 7 mm to the floor of the sinus.

IL29 expression in gingival tissues of chronic periodontitis and aggressive periodontitis patients: An immunohistochemical analysis.

BACKGROUND: Interleukin-29 (IL-29) is one of the cytokines which has immunomodulatory properties and might play a role in the pathogenesis of periodontal diseases. The aim of this study was an immunohistochemical analysis of IL-29 in gingival tissues of chronic and aggressive periodontitis. MATERIALS AND METHODS: In this cross-sectional study based on clinical evaluation and inclusion and exclusion criteria, 20 patients with generalized chronic periodontitis, 13 patients with generalized aggressive periodontitis, and 20 periodontally healthy individuals were enrolled. Gingival tissue samples were obtained during periodontal flap and crown lengthening surgery in periodontal patients and healthy individuals, respectively. Tissue samples were examined to determine the level of IL-29 expression by immunohistochemistry. The data were analyzed using SPSS and paired t-test, ANOVA test, and Tukey's test (P < 0.05). RESULTS: A total of 53 participants (34 females and 19 males) were enrolled in this study. IL-29 expression in the connective tissue of the patient groups was more than the healthy one (P < 0.001). In the aggressive periodontitis group, there was a significant increase of IL-29 expression compared to the other two groups, but there was no significant difference between the chronic periodontitis and healthy groups. CONCLUSION: According to the results of this study, IL-29 expression was increased in the gingival tissue of aggressive and chronic periodontitis. IL-29 local expression in aggressive periodontitis is higher than the chronic periodontitis and healthy groups, which could suggest the role of IL-29 in the etiopathogenesis of aggressive periodontitis.

In vitro assay for osteoinductive activity of different demineralized freeze-dried bone allograft.

PURPOSE: Various bone graft materials have been used for periodontal tissue regeneration. Demineralized freeze-dried bone allograft (DFDBA) is a widely used bone substitute. The current widespread use of DFDBA is based on its potential osteoinductive ability. Due to the lack of verifiable data, the purpose of this study was to assess the osteoinductive activity of different DFDBAs in vitro. METHODS: Sarcoma osteogenic (SaOS-2) cells (human osteoblast-like cells) were exposed to 8 mg/mL and 16 mg/mL concentrations of three commercial types of DFDBA: Osseo+, AlloOss, and Cenobone. The effect of these materials on cell proliferation was determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. The osteoinductive ability was evaluated using alizarin red staining, and the results were confirmed by evaluating osteogenic gene expression using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In the SaOS-2 cells, an 8 mg/mL concentration of Osseo+ and Cenobone significantly increased cell proliferation in 48 hours after exposure (P<0.001); however, in these two bone materials, the proliferation of cells was significantly decreased after 48 hours of exposure with a 16 mg/mL concentration (P<0.001). The alizarin red staining results demonstrated that the 16 mg/mL concentration of all three tested DFDBA induced complete morphologic differentiation and mineralized nodule production of the SaOS-2 cells. The RT-PCR results revealed osteopontin gene expression at a 16 mg/mL concentration of all three test groups, but not at an 8 mg/mL concentration. CONCLUSIONS: These commercial types of DFDBA are capable of decreasing proliferation and increasing osteogenic differentiation of the SaOS-2 cell line and have osteoinductive activity in vitro.