Caspian Journal of Dental Research
Year:2016 | Volume:5 | Issue:1|Papers Count:8

Introduction: Working length determination is important in successful endodontic treatment and retreatment. This study evaluated the accuracy of two electronic apex locators Root ZX and RaypexÒ6 (EALs) in determining the electronic working length (EWL) of the root canals in endodontic treatment and retreatment.Materials & Methods: Access cavities were prepared on forty extracted, single-rooted human teeth and the actual working length (AWL) of the canals was determined. In the first phase of the study, primary EWL of un-instrumented teeth was measured and compared between two EALs. In phase II, all of the teeth were pre-flared and divided into the control (n=10) and the retreatment groups (n=30). Canals in the retreatment group were obturated by the lateral condensation technique using Gutta percha and sealer. After 15 days, gutta-percha was removed, and then the secondary EWL was recorded and compared between the two devices, in treatment and retreatment groups. Data were analysed by paired t-test and t-test.Results: Significant differences were found between both EALs in treatment and retreatment phases of the study (p<0.001). Both EALs showed increased accuracy in retreatment group (p<0.001). However, no statistically significant differences were found between the control and retreatment groups in the second phase of the study for Root ZX (p=0.929), and RaypexÒ6 (p=0.937).Conclusion: Accuracy of the two EALs was similar and acceptable. EWLs determined by Root ZX were closer to the AWL. The EWL determination after pre-flaring improved the accuracy of EALs and root canal obturation remnant materials did not have any clear effect on the accuracy of these EALs.

Introduction: Internal bleaching is a treatment option for wightening endodontically treated discolored teeth. Cervical resorption is one of the side effects of this method. The aim of this study was to compare the sealing ability of resin composite and light-cured resin modified glass ionomer (RMGI) as intra-orifice barriers in internal bleaching.Materials & Methods: In this study, 34 single-canal anterior teeth were used. All samples were endodontically prepared and divided into two experimental groups (n=12) and two control groups (n=5). In the experimental groups, Gutta-percha was removed up to 3 mm below the cemento enamel junction (CEJ). RMGI and composite resin was placed over gutta-percha in the experimental groups up to the level of CEJ. After 24-hours incubation period, the bleaching agent (a mixture of sodium perborate and 30% hydrogen peroxide) was placed in the access cavities. The gnehcaelg agents were replaced every 3 days over 9 days. Then, the access cavity was filled with 2% methylene blue for 48 hours. All samples were longitudinally sectioned and the dye penetration range was evaluated using stereomicroscope. Data was statistically analyzed by using T-student test and variance analysis.Results: The microleakage in RMGI group was 0.945mm and in composite resin group was 0.641mm. Statistically, no significant difference was observed in microleakage between the experimental groups (p=0.121).Conclusion: Both materials can be applied as the intra-orifice barriers for internal bleaching.

Introduction: This in vitro study aimed to compare the antimicrobial effect of lavandula - 0fficinalis extract, with sodium hypochlorite (NaOCL) and chlorhexidine gluconate (CHX), as root canal irrigants, on Enterococcus faecalis (EF).Materials & Methods: Seventy five extracted single-rooted premolars were selected. Root canals were prepared using rotary ProTaper system and were infected with the culture of E. faecalis.Specimens were randomly divided into five groups (n=15), Group 1, 2: lavandula extracts (0.26 and 0.52 mg/mL), Group 3: 2.5%NaOCL, Group 4: 2%CHX, Group 5: Normal Saline. Irrigation was performed for each group for 5, 10 and 15 min. The viable bacteria obtained by collecting the canal dentin chips. Data analysis was performed with Kruskal-Wallis and Mann-Whitney u tests.Results: The mean number of viable bacteria was significantly reduced after 5 min exposure to lavandula solutions (p<0.05). A significant difference also existed between different times in the NaOCL group, being significant between 5 and 15 min (p<0.05), but there was no significant difference between different times in the CHX group. Comparison of the mean number of viable bacteria between different groups at different exposure times revealed that the difference between lavandula and NaOCL solutions with CHX was significant at 5 and 10 min (p<0.05), however, no statistically significant difference was observed between lavandula solutions and NaOCL.Conclusion: lavandula extract was effective in killing of EF. Further studies are necessary to fully understand its other properties such as tissue solubility, removal of smear layer and impact on dentin structure.

Introduction: Since the emergence of normal occlusion concept, selecting an appropriate treatment plan with or without tooth extraction has been a controversial subject. Nowadays, both methods can be successfully used for treatment of patients. However, some clinicians still believe that non-extraction orthodontic treatments have fewer complications. The purpose of this study was to evaluate dental arch dimensional changes following non-extraction orthodontic treatment.Materials & Methods: A total of 200 pre- and post-treatment diagnostic dental casts belonging to 100 patients (non-ext treated by 0.18 roth system) who met the inclusion criteria for this study were collected from the archives of Shahid Beheshti Dental School. Sampling was nonrandomized. A digital caliper with the accuracy of 0.1 mm was used for the measurement of variables such as inter-canine width, inter-premolar width and inter-molar width.Results: Non-extraction orthodontic treatment increased all the variables, except for the mandibular inter-canine width and incisor-canine distance.Conclusion: Non-extraction orthodontic treatment causes a significant increase in almost all dental arch parameters. This increase manifests as teeth flaring.

Introduction: Bleaching of discolored tooth may affect the tooth/composite interface. The aim of this study was to evaluate the effect of different concentrations of carbamide peroxide (CP) on the marginal seal of composite restorations bonded with a self-etch adhesive.Materials & Methods: In this experimental study Class V cavities were prepared on the buccal and lingual surfaces of 24 intact extracted human molar teeth with gingival margins in dentin and occlusal margins in enamel. The cavities were restored using the adhesive system Clearfil SE Bond and the composite Filtek Z250. Finally, they were randomly divided into four groups (1 control and 3 bleached groups). The control group was kept for two weeks in distilled water at 37oC. The bleached groups were bleached with 10%, 22% and 35% CP gel for 8 hours a day for 14 days. After that, the samples were immersed in 0.5% fuchsin solution and sectioned. Then gingival microleakage was graded. Data was analyzed using Kruskal Wallis and Mann Whitney U test (P£0.05).Results: Microleakage was observed in the gingival wall of all groups. There was a significant difference between the control group and the bleached groups. Microleakage in the 22% bleached group was less than the other concentrations, but this difference was not significant.Conclusion: Bleaching with different concentrations of CP can increase the microleakage of the gingival wall of Composite restorations bonded with clearfil SE Bond self-etch adhesive and does not recommend.

Introduction: The aim of this study was to investigate the effect of dentinal pretreatment on the static contact angle of a bonding agent as a measure of dentin surface wettability.Materials & Methods: Twenty mid-coronal dentin surfaces were prepared and randomly allocated to four groups (n=5) according to the priming solutions. All segments were etched with 35% phosphoric acid gel for 15 s, rinsed for 30 s and dried. Each group was rehydrated with 10 μL of distilled water, 0.2 % chlorhexidine, 70% ethanol and 5.25% Sodium Hypochlorite respectively and the excess solution was removed after 60 sec using an absorbent paper. Using a micro syringe, a droplet of the Adper Single Bond 2 was placed on each prepared surface. Then the profile and the static contact angle of the droplet were analyzed with a video-based optical contact angle measuring system. The statistical analysis was performed using One-way ANOVA and Dunnett’s t tests (p<0.05).Results: There was a statistically significant difference between the water and sodium hypochlorite groups which indicates the negative effect sodium hypochlorite may have on dentinal surface energy. (p=0.013). The differences between the water and ethanol groups (p=0.168) and between the water and chlorhexidine groups (p=0.665) were not significant.Conclusion: The use of 5.25% sodium hypochlorite as a priming solution in bonding procedure is not recommended. There is no improvement in dentinal surface wettability by using 70% ethanol or 0.2% chlorhexidine instead of water and the recommendation for use of any of the two should be based on other long-term or short-term effects they may have on the bonding procedure.

Introduction: Periodontal disease is a common chronic inflammatory disease, considered as a primary cause of tooth loss due to the destruction of periodontal tissues. Various studies have shown that vitamin D has anti-inflammatory and anti-microbial properties and plays a significant role in musculoskeletal health. There is strong evidence that vitamin D deficiency may increase the likelihood of osteoporosis and osteopenia as well as chronic inflammatory diseases such as periodontitis.Materials & Methods: This case–control study included 30 females with moderate or severe chronic periodontitis (CP) and 30 periodontally healthy females. The mean age of the CP group and the control group was 34 years. Indices of Probing depth (PD), clinical attachment level (CAL) and bleeding index (BI) as well as the serum level of vitamin D (1, 25 (OH) 2D) were measured in both groups. The statistical analyses including t-tests, Pearson correlation coefficient and odd ratio.Results: There was a significant indirect relationship between the serum level of vitamin D and the periodontal indices (p<0.05). The odd ratio (OR) measures showed that subjects with vitamin D dose of less than 10 ng/ml were 5.6 times more likely to have periodontitis compared to those with a normal dose of vitamin D (p=0.03). Moreover, subjects with vitamin D dose of 10-29 ng/ml were about 1.46 times at a higher risk to develop periodontitis than those with sufficient dose of vitamin D (p>0.05).Conclusion: It is recommended that serum levels of vitamin D in patients with chronic periodontitis be measured and then if necessary, treatment should begin.