An analysis of the relationship between dietary pattern changes and temporomandibular joint inflammation in diabetic rats.

Background: The temporomandibular joint (TMJ) is the most commonly used joint in the human body. Recent studies have shown pathologic relationships between inflammation, diabetes, and musculoskeletal disorders (MSDs). Chewing disorder is a significant sign of dysfunction in the masticatory system. This study investigated dietary pattern changes in response to TMJ inflammation in diabetic rats. Methods: This experimental study was carried out on 30 male rats. The rats were fed concentrated 20-mg dietary tablets. Complete Freund's adjuvant (CFA) was used to induce TMJ inflammation and streptozotocin (STZ) was used to induce diabetes. The animals were randomly divided into three groups (n=10), including group I (CFA+STZ), group II (healthy rats+CFA), and group III (healthy rats, no injection). Parameters such as overall food intake, food intake duration, food intake frequency, and the interval between meals were recorded in a checklist and analyzed by Mann-Whitney and Kruskal-Wallis tests (P<0.05). Results: The results showed no significant difference between groups in overall food intake and food intake frequency on days 0 and 1, but this difference was significant from day 2 to day 7. Regarding the time and end of food intake, there was a significant difference between the three groups from day 1 to day 7, but this difference was not significant on day zero. Conclusion: Dietary pattern changes were similar in the diabetic TMJ inflammation and TMJ inflammation groups. These changes can be used as a behavioral marker for TMJ inflammation in rats.

Effect of Diode Low-level Laser Irradiation Time on Socket Healing.

AIM: The purpose of this research was to survey the effect of low-level laser irradiation time on socket healing in rats. MATERIALS AND METHODS: This randomized nonblinded animal study was done on 24 male rats that were divided into four groups. First maxillary molars of rats were extracted through general anesthesia, and laser was used in all four groups: first group with zero radiation time, second group with 3 minutes, third group with 5 minutes, and fourth group with 10 minutes of radiation by the diode laser (power: 100 mW, wavelength: 980 nm). Half of the rats (three rats) were sacrificed on the 3rd day and another half of rats were sacrificed on the 7th day. Then, the presence of angiogenesis, bone trabeculae, fibroblasts, neutrophil cells, macrophage cells, and lymphocyte cells was assessed. Data were analyzed by SPSS (version 21) using parametric tests. RESULTS: Among 24 rats, on the 3rd day, the percentage of macrophage and bone trabecula increased significantly in the 5 minute group (p = 0.041 and p < 0.01, respectively). Other changes in days 3 and 7 were not statistically significant (p > 0.05). CONCLUSION: Low-level laser radiation can accelerate the process of tooth socket healing, which was particularly noticeable in the 5 minute radiation over 3 days. CLINICAL SIGNIFICANCE: Using a low-level laser can be helpful in accelerating the healing of the tooth socket and reduce the complications after tooth extraction.

Effect of education based on health belief model on observation of standard precautions by dental students in Rafsanjan in 2019.

INTRODUCTION: It is vital importance to observe standard precautions (SPs) in dentistry to prevent the transfer and spread of blood-borne diseases in the community. The aim of the present study was to evaluate the effect of educational intervention using health belief model (HBM) on the observation of SPs by dental students in 2019. MATERIALS AND METHODS: Eighty-seven dental preclinical students were included in the present quasi-experimental study. The students were randomly assigned to two groups, and data were collected using a questionnaire designed based on HBM. Educational intervention was carried out after the pretest analysis in four 60-min sessions. Data were analyzed with independent t-test and paired t-test using SPSS 16 at a significance level of P < 0.05. RESULTS: After the educational intervention, the mean score of awareness (P = 0.001), perceived susceptibility (P = 0.01), perceived severity (P = 0.02), perceived benefits (P < 0.001), cues to action (P = 0.006), self-efficacy (P = 0.002), and behavior (0.03) in the intervention group was significantly increased. CONCLUSION: Despite the effect of education on increasing the students' scores in HBM constructs and observation of SPs, the most important barriers to the adoption of precautionary behaviors were deficiencies in protective tools and aids.

Effect of Topical Honey on Mandibular Bone Defect Healing in Rats.

AIM: In medicine, honey is known for its various biological or pharmacological effects, from wound dressing to anticancero-genic and from anti-inflammatory to antibacterial activities. The aim of the current study was to evaluate the effect of honey on healing of mandibular bone defects in a rat model. MATERIALS AND METHODS: This animal study was performed on 24 wild-type Wistar rats. Following shaving, disinfection, and extraoral incision, a 2 × 2 mm defect was created at mandibular angle. In the experimental group, the defect was filled with sterile honey, while it was left unfilled in the control group. The rats were sacrificed after 2 and 4 weeks and defects were assessed histologically. The results were compared using Mann-Whitney U-test (α = 0.05). RESULTS: After 2 weeks, five samples of the experimental group were in mineralization phase, while all samples of the control group were in the vascularization phase (p = 0.015). After 4 weeks, the defects were filled in four samples of the experimental group, while all samples of the control group were in the mineralization stage (p = 0.002). Histomorphometric assessment revealed that the mean new bone formation in the experimental group was significantly more than the control group, both after 2 and 4 weeks (p = 0.041). CONCLUSION: The results showed that honey could accentuate bone healing of mandibular small defects in rats. CLINICAL SIGNIFICANCE: Honey might have potential in repair of human alveolar bone defects.

Effect of low-level laser on healing of temporomandibular joint osteoarthritis in rats.

OBJECTIVE: Temporomandibular disorders (TMD) are clinical conditions characterized by pain and sounds of the temporomandibular joint (TMJ). This study was designed to assess the effect of low-level laser therapy (LLLT) on healing of osteoarthritis in rats with TMD. MATERIALS AND METHODS: Thirty-two male Wistar rats (250-200 g) were housed in standard plastic cages. After injection of Complete Freund's adjuvant into the TMJ, rats were randomly divided into two groups of 16 (case and control) and anesthetized; then osteoarthritis was induced via intraarticular injection of 50 µl of Complete Freund's adjuvant; into the bilateral TMJs. In the case group, LLLT was done transcutaneously for 10 minutes daily, starting the day after the confirmation of osteoarthritis. Exposure was performed for 10 minutes at the right side of the TMJ with 880 nm low-level laser with 100 mW power and a probe diameter of 0.8 mm. Control rats were not treated with laser. RESULTS: After three days of treatment the grade of cartilage defects, number of inflammatory cells, angiogenesis, number of cell layers and arthritis in rats in the case group were not significantly different compared with controls (P>0.05). After seven days, the grade of cartilage defects, number of inflammatory cells, number of cell layers, and arthritis in the case group improved compared to controls (P<0.05); angiogenesis in both groups was similar. CONCLUSION: Treatment of TMD with LLLT after 7 days of irradiation with a wavelength of 880 nm was associated with a greater improvement compared to the control group.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide.

OBJECTIVES: The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. MATERIALS AND METHODS: A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. RESULTS: All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. CONCLUSIONS: This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.