@article { author = {Mokhtari, Majid Reza and moeintaghavi, amir and Arab, Hamid Reza and bagheri sabzevar, sabete}, title = {Critical Appraisal of Studies Conducted in the Department of Periodontics, Mashhad School of Dentistry, in the Last Twenty Years (1994-2014)}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {1-15}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.17651}, abstract = {Critical appraisal of research studies is an essential process in quality assessments and development, in which various aspects of a subject are carefully analyzed. In recent decades, many articles have been published in medical journals especially in dental field, without being officially criticized. Citing results of these epidemiological studies requires proper validation. The validation is performed through ‘critical appraisal’ according to standard criteria and checklists. In this paper, 81 studies conducted between 1994 and 2014 in periodontics field in dentistry were divided into five categories: observational studies, diagnostic, clinical, animal, and meta-analysis, and reviewed by STROBE, STARD, CONSORT, ARRIVE, PRISMA Checklists. In most studies, participants' characteristics and inclusion and exclusion criteria were mentioned. In most studies, random sampling was not performed without bias. It is hoped that in future studies, researchers will use standard checklists from the initial stages of the study to obtain valid and scientific results.}, keywords = {Critical appraisal,Research Studies,Periodontal}, url = {https://jdmt.mums.ac.ir/article_17651.html}, eprint = {https://jdmt.mums.ac.ir/article_17651_b42888a2ad0393c403e558411d0ad56c.pdf} } @article { author = {Grayli, Ensieh and Peyvandi, Alireza and Mallahi, Maysa and Naeemi, Shabnam and Afshari, Elham}, title = {Radiographic Evaluation of Iatrogenic Errors of Root Canal Treatments Performed in an Undergraduate Dental Clinic}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {16-21}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.17655}, abstract = {Introduction: Iatrogenic errors may occur during root canal treatments (RCTs) performed by undergraduate students. The current study explores the iatrogenic errors of RCTs made by undergraduate students at Gorgan School of Dentistry, Golestan, Iran. Methods: This cross-sectional study was conducted using 236 randomly selected treatment records of RCTs performed on first molars by undergraduate dental students. Periapical radiographs were independently explored for the following errors: overfilling, underfilling, legde formation, and apical transportation. Data analysis was performed using Statistical Package for Social Sciences (SPSS) version 17.0, and a Chi-square test at the 0.05 level of significance. Results: Periapical radiographs of 236 endodontically treated first molars were assessed. The results showed that 87.1% of root canals were adequately filled to the working length. Among the teeth treated by fifth- and sixth-year students, 62.5% and 66.4% of teeth were adequately filled to the working length, respectively, resulting in no statistically significant difference (P>0.05). In respect to the prevalence of ledge formation and apical transportation errors, there was no statistical difference either between the treatments performed by fifth- and sixth-year students (P>0.05) or the location of the treated tooth (mandible or maxilla) (P>0.05). Conclusion: Within the limitations of the present study, the results showed a rather low, but non-negligible prevalence of procedural errors in RCTs performed by fifth- and six-year undergraduate students at Gorgan School of Dentistry. Prevalence of errors made by fifth- and six-year students was similar.}, keywords = {Endodontics,Dental Student,Iatrogenic,Procedural Errors,Radiography}, url = {https://jdmt.mums.ac.ir/article_17655.html}, eprint = {https://jdmt.mums.ac.ir/article_17655_56325483f100fdc0888029ef5a648e78.pdf} } @article { author = {sahebalam, rasoul and Arian, Yeganeh and boruziniat, alireza and Rangrazi, Abdolrasoul}, title = {Microshear Bond Strength and Microleakage of a Restorative Composite Resin with Salivary Contamination at Different Time Intervals}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {22-27}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.17657}, abstract = {Introduction : Saliva contamination is an inevitable and common challenge in the field of restorative dentistry. Recognizing and considering the key time of isolation is an effective strategy to prevent the deleterious effects of salivary contamination. The purpose of this study was to evaluate the effect of salivary contamination in the course of light curing on microshear bond strength and microleakage of a restorative composite resin. Methods: 140 human third molars were divided into seven groups each containing 10 samples for measuring the microleakage and the microshear bond strength. The specimen of each group was contaminated with human saliva at a certain time, while group1 was contaminated in prior to light curing. The samples in groups 2 to 7 were contaminated with saliva at 2, 5, 10, 15, and 20 s after the start of light curing, respectively. The specimens of group7 were light cured and contaminated afterwards with human saliva. Results: According to the gathered results, the time of saliva contamination had significant negative effects on the microshear bond strength to the dentin and enamel in the course of light curing throughout the first 2s and 5s, respectively. It was indicated by the microleacage test that the saliva contamination in the first 2s, 5s, and 10s during light curing had a higher microleakage than the other times. Conclusion: In conclusion, during light curing of the composite resin, the first 10s was high sensitive to saliva contamination and therefore the isolation is very important in this time.}, keywords = {Saliva,Contamination,Composite Resin,Microshear,Microleakage}, url = {https://jdmt.mums.ac.ir/article_17657.html}, eprint = {https://jdmt.mums.ac.ir/article_17657_935130257e467be9643834601d30c71f.pdf} } @article { author = {Doganay Yildiz, Ezgi and Fidan, Mehmet and Dincer, Buket}, title = {Influence of Various Irrigation Protocols on Resistance to Vertical Root Fracture in Root Canal Treated Teeth}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {28-33}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.51819.1393}, abstract = {Introduction: This study compared influence of various irrigation protocols on vertical root fracture resistance of root canal treated teeth. Methods: Forty-eight extracted mandibular premolars were included in the study. The root canals of teeth were instrumented and specimens were allocated into 4 (n = 12) groups according to the irrigation solutions: Group 1: 5% EDTA, 2.5% NaOCl and DW; Group 2: 5% EDTA, 2.5% NaOCl, DW and 2% CHX; Group 3: 5% EDTA, 2.5% NaOCl and 5% Na2S2O3; Group 4: 5% EDTA, 2.5% NaOCl, 5% Na2S2O3 and 2% CHX. Root canals were filled and a load in a vertical direction was applied a week later to specimens. The data were analysed using two-way ANOVA test (P < 0.05). Results: Interaction between using DW or Na2S2O3 and using or not using CHX had a significant effect on fracture resistance to vertical forces (P < 0.001). Irrigation with Na2S2O3 improves fracture resistance to vertical forces when compared to irrigation with DW (P < 0.001). Irrigation with CHX did not affect fracture resistance to vertical forces (P = 0.759). Conclusion: The irrigation solutions statistically affect resistance of root canal treated teeth to vertical fracture forces.}, keywords = {irrigation,final irrigation,sodium thiosulfate,fracture resistance}, url = {https://jdmt.mums.ac.ir/article_17591.html}, eprint = {https://jdmt.mums.ac.ir/article_17591_aa0d449e3bd83d28ff80edc96e7813a4.pdf} } @article { author = {Mohammadipour, Hamideh and akbari, majid and Bagheri, Hossein and Malekmohammadi, Mohammadtaghi and karimian, elnaz and Sekandari, Salehe}, title = {Evaluation and Comparison of Newly Developed Phosphoric Acid Gel (Exir) with Two Different Common Gels in Iran}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {34-43}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.51018.1388}, abstract = {Introduction: Different surface treatments were preposed to prepare the tooth structure for resin composite bonding. One of the most common preparation is using of phosphoric acid etching. This study conducted to determine the etching effectiveness of a new formulated acid etchant (Exir) and compared it with two commercial products. Methods: To determine the physical properties, the viscosity and shelf life were evaluated by a viscometer and a centrifuge over the time, respectively. SEM micrographs were uesd to show the geometry of bovine enamel and dentin surfaces which were treated by three etchants. The µSBS of composite to treated dental tissues was also investigated. Data were analyzed by ANOVA and Tukey test (α=0.05). Results: Exir etchant showed the lower viscosity compared with two other gels and two-phase separation did not significantly increase during suggested period. The SEM images of enamel samples treated with Exir etchant showed regular etching patterns and less remnant in comparison with other groups. The SEM mages of dentin samples treated with Exir etchant, unlike others, showed wide open dentin tubules with clear exposed collagen fibers. Enamel and dentin µSBS were 30.08±6.79 and 7.29±1.27 for Exir etchant, 23.31±6.64 and 8.49±3.61 for Morva Etch and 23.22±7.05 and 6.16±1.68 for Ultra-Etch, respectivley. The µSBS values ​​for enamel was significantly higher in Exir treated group (P=0.017), while there was no significant difference in dentin µSBS values among three tested etchants (P=0.07). Conclusion: The results of this study showed Exir etchant can provide acceptable results used on dentin and enamel substrates.}, keywords = {Phosphoric acid,acid etching,Micro-shear bond strength,Etch pattern}, url = {https://jdmt.mums.ac.ir/article_17633.html}, eprint = {https://jdmt.mums.ac.ir/article_17633_0880e4b0cead7bd65ef234738f9f8624.pdf} } @article { author = {Ostovar Rad, Farzaneh and nemati, somaye and Yousefi, Zahra and Manavi, Nadia}, title = {Retrospective Evaluation of Position of Mental Foramen and Its Relationship with Gonial Angle Using Cone Beam Computed Tomography}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {44-53}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.49596.1378}, abstract = {Introduction: Mental foramen (MF) appearance is quite diverse. Failure to properly diagnose and protect the nerve may result in its damage during medical procedures such as surgery and placement of dental implants. This study evaluated the position of MF and its relationship with gonial angle using cone beam computed tomography (CBCT) images. Methods: 128 gonial angles from 64 CBCT images were measured and divided into low-angle (≤125°) and high-angle (>125°) categories. MF was divided into five types considering its position in cross-sectional profiles: type A (under apex of first premolar); B (under apex of second premolar); C (between first and second premolars); D (anterior to first premolar); and E(posterior to second premolar).The length of mental canal and its buccolingual and superior-inferior position was also evaluated. Independent T-test and Chi-square tests were used with statistical significance set at p Results: The highest frequency of MF position in the high and low-gonial angle categories was type C and the lowest in high-angle and low-angle were type E and D, respectively. The position of the foramen and measurements of the mental canal was not affected by age, gender, or gonial angle (P>0.05). Conclusion: Position of MF was not found to be related to patients’ age, sex, or gonial angles. Since a precise determination of the MF position is difficult due to its different anatomical variations and also because of potential damages during the treatment procedures in this area, radiographic analysis and determining its location among different populations is necessary.}, keywords = {mental foramen,gonial angle,Cone beam computed tomography}, url = {https://jdmt.mums.ac.ir/article_17626.html}, eprint = {https://jdmt.mums.ac.ir/article_17626_412f84e163a3af230a2b1367d0248cae.pdf} } @article { author = {mousavi, seyed mohammad and abdal, khadijeh and noori, meysam and Kazemi, Parisa}, title = {The Impact of Mandibular Advancement Surgery on Upper Lip Length in Class II Patients}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {54-58}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.17642}, abstract = {Introduction: One of the most common maxillofacial malformations is mandibular advancement, a class II malformation or malocclusion. One treatment is mandibular advancement surgery. This research aimed to investigate the effect of mandibular advancement surgery on upper lip length in class II patients. Methods: This retrospective study was conducted with 16 patients having class II malformations who underwent mandibular advancement surgery. Data analysis was conducted using SPSS 19. Results: Results showed that although height of philtrum increased after surgery, there was no significant difference in the height of the philtrum from before to after the mandibular advancement surgery (p > 0.05). Evaluation of the patients showed that although commissure height and vermilion height decreased after surgery, this difference was not statistically different(p > 0.05). However, there was a statistically significant difference between before and after commissure height (p <0.05) at camouflage in patients. There was also a statistically significant difference in height of philtrum and vermilion between before and after camouflage in patients (p <0.05). Conclusions: The results of this study suggest that mandibular advancement surgery plays a serious role in the clinical appearance of lip soft tissue, which can be used as a predictor of patient profile prior to surgery.}, keywords = {Lip vermilion,upper lip,Philtrum,Mandibular}, url = {https://jdmt.mums.ac.ir/article_17642.html}, eprint = {https://jdmt.mums.ac.ir/article_17642_0d4d50b16d2a663b75f65a9d6b41cb3a.pdf} } @article { author = {eftekhari, aida and Bagherpour, ali and Jafarzadeh, Hamid}, title = {Evaluation of the Morphology of Mandibular Incisors using the Cone Beam Computed Tomography}, journal = {Journal of Dental Materials and Techniques}, volume = {10}, number = {1}, pages = {59-61}, year = {2021}, publisher = {Mashhad University of Medical Sciences}, issn = {2322-4150}, eissn = {2252-0317}, doi = {10.22038/jdmt.2021.17664}, abstract = {Introduction: Cone beam computed tomography (CBCT) imaging was developed to provide an improved visual representation of hard dental tissues in three dimensions. This in vitro study aimed to evaluate the morphology of the roots and canals of the mandibular incisors using CBCT. Methods: In total, 100 extracted mandibular central incisors and 100 extracted mandibular lateral incisors were mounted on separate putty blocks, which were completely immobile during imaging. The teeth were imaged using the CBCT unit (kVp=70, mA=8, and exposure time of 12 s). Vertucci’s classification was utilized to record the number of roots and the canals in each root, as well as the type of the canals. Results: Almost all mandibular incisors were single-rooted. Among the mandibular central incisors, the most common canal morphology proved to be type 1 (51%), followed by type 3 (47%). Totally, 2% of the teeth represented type 2 within Vertucci’s classification. Furthermore, mandibular lateral incisors were more varied in terms of anatomical classification. The most common types were recorded as types 3 (55%) and 1 (41%). Moreover, types 6, 2, and 5 comprised 2% of the cases. Conclusion: A high percentage of mandibular incisors have two canals, and based on Vertucci’s classification, the most common anatomies of these teeth were types 1 and 3.}, keywords = {Mandibular incisor,Root canal morphology,Vertucci’s classification}, url = {https://jdmt.mums.ac.ir/article_17664.html}, eprint = {https://jdmt.mums.ac.ir/article_17664_bdb1077924889c7600448bc7a830b400.pdf} }