Caspian Journal of Dental Research

8-13

Authors: Mehrdad Barekatain , Maryam Zare Jahromi , Salma Habibagahi *

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 bleaching 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.

21-28

Authors: Yasser Samadi, Azadeh Harandi *, Ali Soleymani , Soraya Khafri , Saeid Tavanafar

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 Raypex®6 (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 Raypex®6 (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.

36-42

Authors: Shaghayegh Sadeghloo, Fariba Ezoji *, Farnoosh Nikkhah, Hemmat Gholinia

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 37° C. 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.

47-51

Authors: Razieh Eshghi, Fahimeh Rashidi Maybodi*, Arezoo Khabazian, Shahab Shahhosseini

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.