Journal of Mashhad Dental School
Year:2017 | Volume:41 | Issue:4|Papers Count:10

Introduction: Tooth extraction is the most common surgical procedure performed in dental office. Various drugs are used to accelerate wound healing in soft and bone tissues. In this study, the effect of 0.2% chlorhexidine gel and 10% betadine gel on tooth socket healing was investigated.Materials and Methods: This experimental study was performed on 45 male mice randomly divided into three groups of 15. Under general anesthesia, the right maxillary second molar of all of the mices were extracted. The socket of the first group was covered with 0.2% chlorhexidine gel and the second group was covered with 10% betadine gel, and the socket of third group was left empty. On the third, seventh and fourteenth days after surgery, one third of the animals were sacrificed from each group. Then the prepared slides from each group were examined.Results: The extent of granulation tissue on the third day after tooth extraction in the chlorhexidine group was greater than the remaining two groups. The number of lymphocyte on the seventh day after tooth extraction in the chlorhexidine group were lower than the control group. The number of macrophage on the 14th day after tooth extraction in the chlorhexidine and betadine groups was lower than the control group. The number of fibroblasts in the chlorhexidine group on the 14th day after tooth extraction were higher than the control group. These differences were statistically significant.Conclusion: According to the results of this study, 0.2% chlorhexidine gel can accelerate the process of tooth socket healing.

Introduction: Pain control is essential to the behavioral management of children in pediatric dentistry. Effective anesthesia plays a key role in this regard, especially in pulp therapy. In order to achieve successful anesthesia, the type of analgesics and injection techniques should be considered. The present study aimed to compare the anesthetic efficacy of articaine infiltration and lidocaine inferior alveolar nerve block in the pulp therapy of lower primary molars.Materials and Methods: This randomized, crossover, triple-blind clinical trial was conducted on 64 children aged 4-10 years, who required the bilateral pulp therapy of the lower primary molars. Subjects were randomly divided into two groups. Treatment was performed for two sessions, and one lower primary molar was treated in each session. In the first treatment session, subjects in group A were injected with lidocaine inferior alveolar nerve block, and in the second session, they were injected with articaine infiltration. In group B, all the procedures were similar to group A. In the first treatment session, subjects in group B were injected with articaine infiltration, and in the second session, they were injected with lidocaine inferior alveolar nerve block. Pain intensity was measured upon the initiation of the pulp exposure using the visual analogue scale (VAS). Data analysis was performed by crossover analysis, paired t-test, and independent two-sample t-test.Results: During the study period, mean pain intensity in the children treated by lidocaine inferior alveolar nerve block was significantly lower compared to those treated by articaine infiltration. However, the two techniques had no statistically significant difference in the children aged 4-6 years and the treatment of the first primary molars.Conclusion: According to the results, lidocaine inferior alveolar nerve block has higher anesthetic efficacy in the pulp therapy of the lower primary molars compared to articaine infiltration. On the other hand, articaine infiltration could be a proper alternative to lidocaine inferior alveolar nerve block in the children aged 4-6 years and the treatment of the first primary molars considering its greater ease and lower risk.

Introduction: Bond strength between the restorative material and tooth structure is one of the major factors in the selection of restorative materials, which plays a key role in durable restoration and reducing microleakage. Considering the recent attention of researchers to low-shrinkage composites, the present study aimed to compare the micro-shear bond strength of silorane-based composite (P90) with the conventional methacrylate-based composite (Z250) to the dentin of primary teeth.Materials and Methods: In this experimental study, 24 intact primary canines were selected. Two disks (thickness: 2 mm) were prepared from each tooth, and the samples were randomly divided into four groups (n=12). Composite resin cylinders (r=0.7) were adapted on each dentin surface, as follows: g1: (silorane bond system+P90), g2: (etch+silorane bond system+P90), g3: (single bond+Z250), g4: (etch+single bond+Z250). Afterwards, the samples were subjected to a micro-shear bond strength test until failure. Data analysis was performed using Tamhane’s T2 (P<0.05).Results: Statistically significant differences were observed between the four groups of g1, g2, g3, and g4. The highest bond strength was reported in the second group (etch+silorane bond+composite P90), while the third group (single bond+Z250) had the lowest micro-shear bond strength compared to the other groups.Conclusion: According to the results, silorane-based composite (P90) has higher micro-shear bond strength to the primary dentin compared to the methacrylate-based composite (Z250). Moreover, etching the surfaces could increase the bonding efficiency of P90 to the primary dentin.

Introduction: Sinus lift is a process that could be performed by two methods. In the closed sinus lift, hybrid materials enter a suitable position through a created cavity. Afterwards, the materials are pressed without damaging the sinus membrane, and the implants are usually placed at the same time. Closed sinus lift is carried out via osteotomy and piezosurgery, and each of the techniques has certain advantages and limitations. The present study aimed to compare the clinical results of closed sinus lift using the summers osteotomy and piezosurgery.Materials and Methods: In this study, 20 patients requiring dental implants in the posterior segment of the maxilla via sinus lift surgery were randomly divided into two groups. The first group received piezosurgery, and the second group underwent summers osteotomy for sinus lift. Postoperative Schneiderian membrane perforation, inflammation, pain, bone gain, and bone loss were compared between the groups six months after the surgery using Mann-Whitney U test and two-sample t-test.Results: In the groups receiving piezosurgery and summers osteotomy, mean sinus lift was 3.6±0.9 and 4.0±2.2 mm, pain score was 1.1±1.2 and 0.9±0.8, bone gain was 2.2±0.8 and 3.1±1.3 mm, and crestal bone loss was 1.1±1.2 and 0.9±0.8 mm, respectively. Moreover, no Schneiderian membrane perforation was observed in the two methods, and the differences between the groups were not considered significant (P>0.05).Conclusion: According to the results, the clinical outcomes of piezosurgery in sinus lift are similar to those of summers osteotomy. Therefore, piezosurgery could be a proper alternative to summers osteotomy in sinus lift surgery.

Introduction: Precise knowledge of the location of the apical constriction is essential to root canal treatment and long-term prognosis. Considering the differences in the apical constriction and size of the roots in single- and multiple-root teeth in various races, examination and comparison of the location of the apical constriction in single-root and multiple-root teeth are of paramount importance. The present studies aimed to measure and compare the distance of the apical constriction from the apical foramen and anatomical apex in single-root and multiple-root teeth.Materials and Methods: In this cross-sectional study, 60 roots of single-rooted teeth and 60 roots of multiple-rooted teeth were collected from the patients referring to the health centers in Isfahan, Iran. After cleansing and disinfecting the surface of the roots, the surface of the teeth was washed with hypochlorite. Based on the direction of the apical foramen, a longitudinal cut was made in the same direction, and the roots were examined microscopically at the magnification of 25. Following that, the distance of the apical constriction from the apical foramen and anatomical apex was measured using a digital camera. In addition, mean and standard deviation of the obtained distance values were determined. Distances in the single -root and multiple-root teeth were compared using independent t-test, at the significance level of <0.05.Results: Mean distance between the apical constriction and apical foramen was 0.86±0.33 mm in the single-root teeth and 0.072±0.27 mm in the multiple-root teeth. Mean distance between the apical constriction and anatomical apex was 1.14±0.36 mm in the single-root teeth and 1.03±0.36 mm in the multiple-root teeth. Moreover, the results of independent t-test showed the distance of the apical constriction from the apical foramen to be significant between single-root and multiple-rooted teeth (P=0.013). However, the distance between the apical constriction and anatomical apex was not considered significant in single-root and multiple-root teeth (P=0.095).Conclusion: According to the results, the termination of root canal treatment should be 0.86 and 0.024 mm shorter than the apical foramen, while it should be 1.14 and 1.03 mm shorter than the anatomical apex in single-root and multiple-root teeth, respectively.

Background & Objective: Continuing professional development is a key method to meet the intended professional standards, as well as an important source of the required information for appraisal revalidation and recertification. Discovering the strengths and weaknesses of the continuing dental education (CDE) program is essential for dentists. In this regard, evaluating comparative studies and benefitting from the experiences of successful universities are of paramount importance. The present study aimed to compare the elements of CDE in Iran with the high-ranked CDE in other countries.Materials and Methods: Data were collected via searching in the CE websites of various countries. These programs were compared in terms of their elements, including organization, provider, teaching and learning methods, curriculum and learner evaluation, and educational contexts and resources. In addition, the Beredy pattern was used, which determined the four stages of description, interpretation, proximity, and comparison in comparative studies.Results: CDE program in Iran was observed to be favorable in some elements, such as learning and teaching methods and program evaluation, while other subjects, such as communication skills, marketing, economy, and office supplies, could also be added to the courses. With regard to the organizations and providers, all the CDE programs in Iran are formally conducted by institutions and universities as the providers, while in other countries, professional associations, industries, and commercial companies are involved in establishing the accredited CDE program.Conclusion: Despite the strengths in the CDE program in Iran, some limitations need to be improved through the continuous validation and modification of these affairs. Major revisions in this regard must include modifying the teaching methods, adding suitable subjects with higher practical importance, and updating the subjects based on the ongoing professional needs. In general, findings of this study could largely contribute to the developers and modifiers of the CE curriculum in Iran.

Introduction: Topical fluoride may deteriorate dental restorations. The present study aimed to evaluate the effects of topical fluoride on the marginal microleakage of composite resin and resin-modified glass ionomer (RMGI) restorations in primary molars.Materials and Methods: In this experimental study, 60 primary molars were randomly divided into six groups of 10 based on the type of the restoration materials and before/after the application of fluoride gel, including FC (fluoride+composite), CF (composite+fluoride), C (composite), FG (fluoride+RMGI), GF (RMGI+fluoride), and G (RMGI). Class V cavities were prepared on the buccal surface, so that the gingival margins were located in cementum. After storing, thermocycling, and immersing the specimens in basic fuchsin, they were sectioned buccolingually and evaluated in terms of dye penetration. Data analysis was performed in SPSS version 18 using Kruskal-Wallis and Mann-Whitney U test at the significance level of 0.05.Results: No significant difference was observed between the three composite groups in terms of microleakage (P>0.05). In the RMGI groups, GF showed a significantly higher microleakage compared to G (P=0.029). However, no significant difference was observed between the other groups in this regard (P>0.05). Moreover, comparison of composite and RMGI groups (matched in terms of fluoride application) indicated that microleakage was significantly higher in FG than FC (P=0.024), as well as in GF than CF (P=0.002). However, no significant difference was observed between groups C and G in this regard (P=0.268).Conclusion: According to the results, the marginal seal of composite restorations in the primary molars were not affected by the acidic fluoride gel. On the other hand, applying the acidic fluoride gel was associated with a higher microleakage in the cavities restored with RMGI.

Introduction: While using an implant-supported removable partial prosthesis, the implant abutments should be parallel to one another along the path of insertion. If the implants and their attachments are placed vertically on a similar occlusal plane, not only is the retention improved, the prosthesis will also be maintained for a longer period.Case Report: A 65-year-old male patient referred to the School of Dentistry in Mashhad, Iran with complaints of discomfort with the removable partial dentures for his lower mandible. Due to the lack of parallelism in the supporting implants, prefabricated ball abutment could not be used. As a result, a customized ball abutment was fabricated in order to correct the non-parallelism of the implants.Conclusion: Using UCLA abutments could be a cost-efficient approach for the correction of misaligned implant abutments in implant-supported overdentures.