Titanium (Ti) and its alloys are widely used as dental implant materials because of their high mechanical properties, biocompatibility, and corrosion resistance. This research was undertaken to study the effect of polymethyl-methacrylate (PMMA) sealing layer on the corrosion performance of plasma electrolytic oxidation (PEO)-coated titanium-based dental implants in pure saliva and fluoride-containing saliva solutions. The phase structure, chemical composition, and microstructure of coatings were investigated via X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy, respectively. The corrosion behavior of the samples was evaluated by open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy tests. The deposition of the PMMA layer on the PEO-coated Ti dental implants was found to effectively seal the micropores and microcracks of the TiO2 coatings and block corrosive ions' penetration routes through the coating. Thereby, the results indicated that better corrosion performance was observed when the PMMA layer is applied on PEO-coated Ti dental implants than on the simple PEO coatings.

BACKGROUND: Oroantral fistula (OAF) is a pathological communication between maxillary sinus and oral cavity, which treated by various surgical methods including buccal flap and associated with post-operative discomfort and relatively long healing period. AIM: The objective of the study was to evaluate the effect of 0.2% hyaluronic acid (HA) gel on the healing period after surgical buccal flap treatment of OAF. METHODS: The records of 20 patients of both genders included and reviewed retrospectively. Ten patients treated with topical 0.2% HA gel while the other 10 patients treated without it. Patients healing process followed up for suture removal appointment. RESULTS: Statistically significant p ≤ 0.05 decreases in healing period when we compare patients treated with topical HA gel and those without topical HA gel. CONCLUSION: The use of topical HA gel may have advantages for soft-tissue healing and decrease healing period for patients has OAF treated with surgical buccal flap.

Anterior mandibulotomy (mandibular swing) is an essentialsurgicalapproachto tumors of the oral cavity, oropharynx and parapharyngeal space. Objectives: to evaluate the feasibility of the technique, to determine frequency of complications and outcomes.This study consisted of 11 patients surgically treated for primary tumors in oral cavity, oropharynx and parapharyngeal space which included 7 females (64%) and 4 males(36%) with a mean age of 41.3 years, range from 40-65 years; lesion size range was 4-8 cm in greatest dimension. All patients underwent planned mandibular swing approach as part of the ablative surgery for different lesion in oral cavity, oropharynx and parapharyngeal space. Preoperative work-up included mandible evaluation with panoramicradiography that provided information on the dental anatomy and the mental foramen position. The mandibular swing approach that performed for patients has been evaluated regarding the surgical exposure which was obtained and achievement of these procedures.Paramedianmandibulotomy was used in 9 cases (82%) which used for exposure of lesions in oropharynx and parapharyngeal space, while median mandibulotomy was used in 2 cases (18%) which used for lesions in oral cavity. monocortical plate and screws were used in ten cases (91%), while transosseous wiring used in one case (9%) which result in subsequent nonunion mandibular osteotomy site. In ten cases (91%) the exposure was good, while in one case (9%) the exposure was limited. these procedures allow total removal of lesion in ten cases(91%) and it alloweddebulking of one case (9%). Only three patients (27%) have been received postoperative radiotherapy as adjuvant treatment for malignant lesion. The complication related to mandibular swing approach has been assessed and it was found that complication rate through the following up period that range from 6 -18 months was 36%. One patient had lost one of the incisors adjacent to the mandibulotomy site during the operation. One patient suffered from bony nonunion, one patient suffered from facial neuroparesis due to marginal mandibular nerve injury. The complication rate related to osteotomy was 18%.The lower lip splitting with paramedianmandibulotomy with miniplate fixation, is a safe, simple and reliable technique for providing excellent access to tumor of the oral cavity, oropharynx and parapharyngial space.

Objective Head and neck cancer (HNSC) is the sixth most usual type of cancer in the world. The heterogeneity of this type of cancer is more elevated by the rising rate of human papillomavirus (HPV)-related (HPV+) HNSC, which defines an etiological subtype significantly different from the more common tobacco and alcohol associated HPV-negative (HPV-) HNSC. The aim of this study was to identify the RNA-binding proteins (RBPs) with immune role, and study of their relation with HPV status and drug resistance. Methods By using the Cancer Genome Atlas (TCGA) and utilizing clinical data, at the first, differential expressed RBPs analysis was performed and among selected RBPs, the genes which consider as immune genes were identified. Then, downstream analyses to characterize this tumor based on HPV status, including pathway mapping, survival analysis, immune infiltration and drug resistance was conducted. Results 99 differentially expressed genes were detected that were similar in RBPs genes and immune genes (IGs) in HNSC. These genes were enriched in some significant pathway and the association of candidate genes with HPV were applied by Chi-squared test and the level of which were evaluated in HPV + and HPV -. Then, the prognostic value of genes was evaluated in HPV + and the correlation of them with immune infiltration and drug resistance was evaluated. Conclusions Identifying the RBPs with immune role and recognizing the molecular differences between HPV + and HPV − tumors could cause the opportunity to find specific genes and the therapeutic approaches for targeting them.