Effect of Topical Application of Dentol Drop on the Success of Inferior Alveolar Nerve Block for Teeth with Irreversible Pulpitis: A Double-blind Randomized Clinical Trial

Introduction: The failure rate of inferior alveolar nerve (IAN) block is high for mandibular molars with irreversible pulpitis. This double-blind, randomized, clinical trial aimed to assess the effect of topical application of Dentol drop on the rate of successful anaesthesia of mandibular molars with irreversible pulpitis due to deep carious lesions. Methods and Materials: Seventy-two patients with mandibular first and second molars with irreversible pulpitis and deep cavitated carious lesions participated in this study. The patients were randomly assigned to the test and control groups (n=36). In the test group, a cotton pellet, dipped in Dentol drop, was placed in the cavity for 10 min. A placebo was used _in the same manner_ in the control group. Level of pain was measured before the intervention, 15 min after anaesthesia (when patients reported numbness at the corner of the mouth), during access cavity preparation, upon pulp exposure and after introduction of the initial file into the root canal; using a Heft-Parker “Visual Analog Scale” (VAS). Data were analysed using ANCOVA. Results: Levels of pain were recorded during access cavity preparation (P<0.001), pulp exposure (P<0.001) and file introduction into the canal (P=0.018). In the test (Dentol) group, the obtained levels of pain were significantly lower than those of the corresponding values in the control group. Conclusion: Topical application of Dentol drop increased the success rate of IAN block for root canal treatment of mandibular molars with irreversible pulpitis.Keywords: Dentol Drop; Inferior Alveolar Nerve Block; Irreversible Pulpiti

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla

The Effect of Gates-Glidden Drills on the Quality of Root Canal Treatment by Pre-Clinical Dental Students

AIM: This study was conducted to investigate the effect of applying Gates-Glidden (GG) drill by pre-clinical dental students on root canal treatment quality. METHOD: A total of 56 first molars consisting of 168 canals were selected in this study. For this purpose, 56 students who had been formerly trained by two methods of root canal preparation were randomly divided into two groups (n = 28). Group 1: the step-down method by GG and Group 2: step-back technique without GG. The prepared teeth were filled with gutta-percha/ZOE sealer using lateral condensation. Periapical radiographs were taken before and the following treatment to survey occurrence of preparation errors and CBCT images to determine residual dentine at furcation region. RESULTS: The findings showed that among 10 error types in specimens prepared by students, the occurrence of underfilling, overfilling, inappropriate, ledge formation, and single cone was more common without GG. There were no significant differences in residual dentine amount at furcation region between preparation with and without using GG (P > 0.05). CONCLUSION: Using GG for root canal preparation by dental students resulted in low errors and not an increased dentine removal risk

Applying the Taguchi Method to the Optimization of Anticancer Activity of Bacterial Alginate-CuO Bionanocomposite

AIM: In recent decades, despite various types of cancer inflicting many people worldwide, the existing therapies are not satisfactory and have many side effects. The present study was conducted to optimise the synthesis of novel alginate-CuO nanocomposite with utmost anticancer activity. METHODS: In this study, 9 nanocomposites were designed using Taguchi method and three factors including copper oxide nanoparticles, alginate biopolymer and stirring times were assessed at three different levels. The anticancer activity of the synthesised nanocomposites was evaluated on the MCF-7 cell line using the MTT method. Using the Qulitek-4 software, we determined the optimum conditions for the synthesis of alginate-CuO nanocomposite with the highest anticancer activity. RESULTS: The results indicated that all three factors (copper oxide, alginate and stirring time) were effective on the anticancer activity of the alginate-CuO nanocomposite. Also, the nanocomposite produced under the conditions of experiment 9 (8 mg/ml of copper oxide, 2 mg/ml of alginate and 60 min of stirring time) provided the highest growth inhibition rate as 75.63% against cancer cells. CONCLUSION: The synthesised alginate-copper oxide nanocomposites in this study showed a significant anticancer effect. Therefore, the synthesised nanocomposite under optimal conditions can be used in the design of new anticancer drugs

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla

Knowledge of General Dentists of Kermanshah about Root Canal Therapy in 2012

Introduction: The present study was conducted to analyze the knowledge of general dentists of Kermanshah about root canal therapy in 2012. Methods: In this descriptive cross-sectional study, a two-part questionnaire was designed and given to 93 general dentists in Kermanshah to complete. The first part of the questionnaire comprised of personal and professional information of the participant dentists and the second part of the questionnaire determined the awareness of the dentists about root canal therapy. Data were analyzed by SPSS software (version 20) using Pearson correlation coefficient, one-way analysis of variance (ANOVA) and independent t-test. Results: A total of 84 dentists with the mean age of 39.3±7.1 completed the questionnaires. The mean for 12 correct responses was 63.3%. The highest number of correct responses (86.2%) belonged to using proper intra-canal medication (calcium hydroxide) and the lowest number of correct responses (41.4%) was associated with the number of root canals in maxillary first molar (four canals). There was a reverse correlation between awareness and work experience (P=0.002, r=-0.337). Also, participation in retraining courses did not have significant impact on the knowledge of the dentists (P =0.82). Conclusion: General dentists have average knowledge about root canal therapy. Higher quality regular training is recommended to promote the knowledge of the dentists about endodontic therapies

Sperm matrix metalloproteinase-2 activity increased in pregnant couples treated with intrauterine insemination: a prospective case control study

Matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) have an important role in the reproductive system and in the fertilisation process. The aim of this study was to investigate the MMP2 and MMP9 activity in semen and their association with the pregnancy rate, semen parameters and seminal plasma oxidative stress parameters in couples who were treated with intrauterine insemination (IUI). The semen specimens were obtained from 60 men who attended with their spouse for the IUI in the infertility unit. A controlled ovarian stimulation was performed with clomiphene citrate in IUI cycles. Women with positive pregnancies were recorded (n = 29). The results showed the activity of sperm MMP2 and seminal plasma MMP9 was significantly higher in the pregnant group, compared to the non-pregnant group (p < .05). There was a correlation between the sperm MMP2 activity and the total thiol group (TTG) (r = 0.276, p < .05) and the total antioxidant capacity (TAC) of seminal plasma (r = 0.304, p < .05). The sperm MMP9 showed a positive correlation with the seminal plasma TAC (r = 0.330, p < .05) and an inverse correlation with the lipid peroxidation (LP) of seminal plasma (r = –304, p< 0.05). In addition, the seminal plasma MMP2 activity was correlated to sperm viability (r = 0.266, p< .05) and the TTG of seminal plasma (r = 0.298, p < .05). The MMP2 activity in the sperm may be an important factor for determining the pregnancy rate after IUI.Impact statement What is already known on this subject? Previous studies have reported that the fusion between the sperm and zona pellucida required the activity of matrix metalloproteinase 2 (MMP2), whereas the inhibition of MMP2 can significantly decrease the in vitro fertilisation (IVF) rate. What do the results of this study add? This study has identified that the sperm MMP2 activity was significantly higher in the pregnant couples in comparison with the non-pregnant couples, who treated with intrauterine insemination (IUI). The findings showed there was a correlation between sperm MMP2 activity and the total thiol group (TTG) and the total antioxidant capacity (TAC) of the seminal plasma. What are the implications of these findings for clinical practice and/or further research? MMP2 activity in the sperm could influence the IUI outcome and it is an important factor for IUI success

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique

Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one-and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4 ∘ . Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by onestage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one-and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique