Assessment of cell phone effect on dental socket healing in rat.

BACKGROUND: Electromagnetic waves can cause biological effects on repair process. Due to the proximity of the jawbone and the soft tissue around it in a part of the face with which it has the closest contact during the cell phone use, this study aims to investigate the effect of mobile waves on socket healing after tooth extraction in rats. METHODS: This experimental study was conducted on 32 rats. The case group was exposed to a 900 MHz frequency electromagnetic field for 30 min/d. Sacrificed eight rats from the case group and 7 rats from the control group on day 14, and 8 rats from the case group and 7 rats from the control group were sacrificed on day 28 at the end of the radiation period and CBCT and microscopic examinations on the maxillary bones and soft tissue were performed. RESULTS: According to the findings, the healing process was significantly different in two groups in terms of the percentage of new bone formation on day 14 after the end of radiation (P=0.014). The other measured parameters including the degree of inflammation, thickness of the formed bone, number of osteoblasts and Gray Scale had no significant difference between the two groups in any of the 14-day and 28-day intervals. CONCLUSIONS: The results of this study showed that intermittent exposure to high frequency electromagnetic fields over a period of 20 hours has no significant effect on the healing process of alveolar socket after tooth extraction in rats.

Prevalence of Merkel Cell Polyomavirus (MCPyV) in the Oral Cavity Biopsies in Northern Iran.

OBJECTIVE: Infection with human tumor viruses is one of the hypothesized causes of cancer. The current investigation aimed to explore the presence and quantitative analysis of a new human tumor virus, Merkel cell polyomavirus (MCPyV) in tissue samples of 114 patients with oral cavity lesions including oral squamous cell carcinoma (OSCC), oral lichen planus (OLP), Dysplasia and oral irritation fibroma (OIF) in Northern Iran. METHODS: From 114 formalin fixed paraffin embedded samples; 35 with SCC, 29 with OLP, 14 with dysplasia and 36 with OIF were cut, deparaffinized and DNA was extracted. Quantitative detection of MCPyV large T antigen was performed by absolute quantitative Real-Time PCR. RESULT: MCPyV DNA was detected in 30.6% (n: 11/36) of IF, 24.1% (n; 7/29) of OLP, 21.4% (n:3/14) of dysplasia and 20% (n;7/35) of OSCC samples. The mean MCPyV DNA copy number was 2.32×10-2 ± 3.97 ×10-2, 2.02×10-2 (SD=3.13×10-2), 2.69×10-4 (SD=2.51×10-4), and 2.56×10-4 (SD=6.73×10-4) per cell in OSCC, dysplasia and both of OLP and OIF samples, respectively (P=0.76). CONCLUSION: This study provides the first data from Iran regarding the presence of MCPyV genome in oral cavity lesions and oral cancer. These results also emphasize that MCPyV has an active role in the occurrence of oral lesions and progression to cancer. Further studies should be carried out to clarify the role of MCPyV in oral cavity lesions.

Biocompatibility of Mineral Trioxide Aggregate Mixed with Different Accelerators: an Animal Study.

STATEMENT OF THE PROBLEM: Several additives have been introduced to decrease the setting time of MTA (mineral trioxide aggregate). For clinical applications, it is essential to investigate the biocompatibility of these materials. PURPOSE: The present study evaluated the tissue response to MTA that has been separately mixed with citric acid, calcium lactate gluconate (CLG), and Na2HPO4. MATERIALS AND METHOD: In this experimental study Twenty one Wistar rats were divided into three groups of 7, 14 and 30 days follow up periods. Sterile polyethylene tubes were subsequently filled with MTA separately mixed with distilled water, 0.1% citric acid, 0.43% calcium lactate gluconate (CLG) and 15% Na2HPO4 and afterwards implanted subcutaneously. Empty tubes were implanted as negative control. At the end of their respective periods, the animals were sacrificed by anesthetic overdose and a biopsy was performed. The inflammatory responses were scored, classified and statistically analyzed using Kruskal-Wallis and Man-Whitney tests. Statistical significance was defined as p< 0.05. RESULTS: There was no significant difference between test groups in any time period after implantation but the mean values of inflammatory responses were significantly more than that of the negative control group (p> 0.05). The mean values of inflammatory responses were decreasing over time in all test groups. These values did not significantly differ in any group except the CLG and Na2HPO4 groups. CONCLUSION: The inflammatory responses induced by MTA mixed with citric acid and MTA mixed with Na2HPO4 were comparable to that of the control MTA. MTA mixed with CLG provoked a moderate-to-severe inflammatory response at 7 days after implantation, so further study is required before clinical application of this cement.

Evaluation of knowledge, attitude and practice of general dentists regarding oral cancer in sari, iran.

BACKGROUND: Oral cancer has emerged as a significant cause of global public health concern. If a cancerous lesion is diagnosed in primary stages, the survival rate would be higher. Thus, the aim of this study was to evaluate knowledge, attitude and practice of general dentist regarding oral cancer in Sari, Iran. METHODS: This cross sectional analytical study was performed on general dentists of Sari, Iran. The dentists were given a questionnaire including demographic characteristics of the dentists and questions about knowledge, attitude and practice regarding oral cancer. Data were subjected to SPSS 18.0. Quantitative data were reported as mean (±SD) and qualitative data were shown as percent. Kolmogorov- Smirnoff sample test, t-test (p<0.07 was considered statistically significant)' equivalent nonparametric test and Spearman's rho test was used for statistical analysis. RESULTS: Total mean score of knowledge, mean score of females and mean score of males was 20.88±8.53, 20.96±7.62 and 20.71±10.43, respectively. Age and sex had no correlation with score of knowledge. CONCLUSION: Dentists of Sari do not have enough knowledge about oral cancer.