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Background: There are controversies on the analgesic and anti-inflammatory effects of low-level laser therapy on pain, edema, and trismus after mandibular third molar extraction surgery. This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) on discomforts occurring after the mandibular wisdom tooth removal. Materials and Methods: This double-blind, split-mouth design, randomized clinical trial study was performed on 36 healthy controls with bilateral symmetrical mandibular third molar referred to the Department of Oral and Maxillofacial Surgery of Dental Faculty from January to November 2019. After surgical extraction, the laser group underwent laser (Ga-Al-As diode laser, 808 nm, 200 mW) intraorally and extraorally just after surgery and 24 h after surgery. For the placebo group, the handpiece was inserted without laser irradiation. The pain level was assessed by Baker Wong scale at 2, 4, 6, 12, 24, 36, 48, and 60 h postoperatively, and the edema and the extent of mouth opening were examined before surgery, at the 1st and 7th days after surgery. The data were collected and analyzed by SPSS at the significant level of 0.05. Results: The statistical analysis of 32 participants' data (laser group: n = 32, placebo group: n = 32) indicated that the mean score of pain in 3 days after surgery in the interventional group was significantly lower than the score of the placebo group (P < 0.001). Furthermore, the swelling and the extent of the mouth opening differed significantly between the two groups at 1st and 7th days after the procedure (P < 0.001). Conclusion: Our findings showed that the LLLT had beneficial effects on the management of pain, edema, and trismus following after 3rd molar extraction surgery.
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OBJECTIVE: The purpose of this study was to measure the thickness of the palatal bone using cone beam computed tomography images for placement of mini-screws and their relationship with palatal vault depth. METHODS: This study was performed on 150 maxillary cone beam computed tomography images, 50% (n = 75) had deep palate and 50% (n = 75) had normal palate and 27.3% (n = 41) were male and 72.7% (n =109) were female. Coronal sections with a thickness of 1 mm were prepared at distances of 4 mm, 8 mm, 12 mm, 16 mm, 20 mm, and 24 mm from the posterior wall of the incisive foramen. Then, in each section, in the midsagittal line and at distances of 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm from that to the lateral sides, the bone thickness was measured. The Korkhaus index was used to identify the patients with a high palatal vault. RESULTS: The results showed that at the posterior sections in the midsagittal and parasagittal area, a significant difference (P < .05) was observed between deep and normal palate, and in these points, the bone thickness in the normal palate was greater. Also, in the section of 4 mm and 8 mm, a significant difference was observed between males and females in most of these points, and those were greater in males than females. CONCLUSION: The maximum thickness of the palatal bone was observed first along the midsagittal line and then the paramedian and in the anterior section. Patients with deep palate had less palatal bone thickness in the posterior sections.
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Purpose: This study aimed to determine the expression of Bone Morphogenic Protein-4 (BMP-4) in dentigerous cyst (DC), unicystic-ameloblastoma (UA), and Multicysticameloblastoma (MA), and assess whether this marker can be a differentiation measure. Materials and methods: This study included 30 DC, 30 UA, and 30 MA blocks if the histopathologic diagnosis of the lesion was definitive, the clinical information and medical records were complete, and the microscopic slides and the paraffin block were available. Age, gender, and location of the lesion were recorded. The samples were analyzed after the immunohistochemical staining (Envision technique). BMP-4 marker was evaluated and reported using Intensity Score (IS), Proportional Score (PS), and Total score (TS). The data were analyzed using SPSS version 21.0. Kruskal-Wallis and Mann-Whitney U tests were applied at the significance level of 0.05. Results: In this study, DCs, UA, and MA had a significant tendency to occur in males compared to females (p<0.001, p<0.001, and p<0.001 respectively), and in the mandible compared to the maxilla (p=0.02, p=0.024, and p=0.02 respectively). The epithelial IS was significantly different among three lesions (p<0.001). IS was higher in MA than UA and DC (p<0.001 and p=0.006, respectively). The IS was not significantly different among the three lesions in connective tissue and around micro-vessels (p=0.3 and p=0.26 respectively). The PS in the epithelium and connective tissue of DC, UA, and MA had no statistical difference (p=0.549 and p=0.540 respectively). The epithelial TS was statistically different among DC, UA, and MA (p<0.001). The TS was higher in UA than MA and DC (p=0.004 and p<0.001 respectively). Conclusion: The expression of BMP-4 in the epithelium was higher in ameloblastoma compared to DCs. BMP-4 is a potential measure to differentiate different types of ameloblastoma and dentigerous cyst. The differentiation of these lesions is important as the right treatment plan changes according to the diagnosis.
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OBJECTIVE: The purpose of this study was to investigate the pulpal effect of diode low-level laser therapy (LLLT) of 810 nm on the alleviation of pain in patients requiring dental procedures. METHODS: The current study was a double-blind randomized clinical trial carried out on twenty participants. The electric pulp testing (EPT) was recorded at baseline. Patients were randomly divided into sham laser and laser group respectively receiving low-level laser with placebo and active probes. Low-level laser at 810 nm, 200 MW constant power, 30s irradiation time and energy dose of 6 J was used. The electric pulp testing (EPT) method was again adopted to assess the rate of induced anesthesia. Laser and sham laser treatments were carried out in two different sessions with a one-week interval to ensure avoiding the potential false placebo results. Data were analyzed in SSPS-24 using Chi-square test and t-test. The p-value was set at 0.05. RESULTS: A low-level laser at 810 nm significantly alleviate EPT-induced pain compared to the pain before laser irradiation (P≤0.001). While the difference of EPT-induced pain before and after sham laser irradiation was not significant in control group (P>0.05). There was no correlation between the anesthetic effects of a laser application at 810 nm and other variables including age and gender (P>0.05). CONCLUSION: An 810 nm low-level laser is a powerful device for induced anesthesia applications in patients requiring dental procedures. It also lessens the patients' fear of dental procedures.
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BACKGROUND: One of the concerns in using composite resins is color change. The aim of this study was to investigate the effect of preheating on color stability of composite resins when immersed in coffee and tea. MATERIAL AND METHODS: This experimental study included 60 composite disks. The samples were divided into 2 groups, one group prepared at room temperature and the other prepared at 68 °C. After curing, the samples were placed in 37 °C distilled water for 24 hours. The color of the samples was measured (t0) using spectrophotometer according to CIE-L*a*b* system. The samples of each group were then divided into 3 subgroups and respectively immersed in distillated water, coffee and tea for 30 days and the final color (t1) was measured. The difference between the measured colors was calculated (∆E) and the results were analyzed using version 21.0 of SPSS software, Paired t-test, ANOVA, Tukey's test, and Dunnett t-test. RESULTS: The preheated composites showed significantly lower staining in the coffee solution than the room temperature composites (p<0.0001). In contrast, no statistically significant difference was observed for the tea solution (p =0.317). The staining of the preheated composites in distillated water was higher than those in the room temperature, however, the difference was not significant (p =0.99). CONCLUSIONS: Within the limits of this study, preheating was effective to improve color stability of composite resin after long time immersion in coffee solution. Key words:Composite resin, color stability, preheating.
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BACKGROUND: Methotrexate (MTX) is an immunosuppressive drug, widely used in inflammatory disturbances including rheumatoid arthritis. However, there is no consensus regarding the effect of MTX on implant osseointegration. OBJECTIVE: The purpose of this experimental study was to investigate the effect of low dose MTX on Bone-Implant Contact (BIC) of dogs. METHODS: Six mandibular premolar teeth (bilateral) of 8 mature dogs were extracted. After 3 months of healing, 6 implants (bone level, resorbable blast media surface) were inserted into the mandible of each dog (3 in each side). Dogs were randomly divided into a study group (receiving 2.5 mg/week MTX orally, 3 times per week for 4 weeks) and a control group each containing 4 dogs. In the 1st week, postoperative BIC was evaluated in 4 dogs, two from each group. In the 4th week, reverse torque and BIC were evaluated in the remaining 4 dogs. Data were analyzed with two-way ANOVA test for 95% confidence interval. RESULTS: The reverse torque test of the 4th week, showed a satisfying osseointegration. Histopathologic evaluation revealed that the BIC was significantly higher in the control group in comparison to the MTX group in the 1st and 4th week. In addition, the BIC of both groups were significantly increased in the 4th week in comparison to the 1st week in both groups. CONCLUSION: MTX has the potential to interfere with osseointegration process.
