Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro root MTA in in-vitro and in-vivo studies have been proven. On the other hand, based on some studies, root MTA (Iranian Pro root MTA) and Portland cement are similar to Pro root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time) of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro root MTA, white Pro root MTA, root MTA (Iranian Pro root MTA), Portland Cement (type I) and positive and negative control groups. root canals were instrumented using the step- back technique. root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556). Culture media were observed every 24h for color change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro root MTA, White Pro root MTA. root MTA and Portland Cement (type I) had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time) of the four tested root- end filling materials (P=0.9958). Conclusion: Based on the results of this study, there were no significant differences in leakage among the four tested groups at 60 days. The results suggest that root MTA and Portland Cement can be used as less expensive root filling materials.

Background: The purpose of the present study was to evaluate the influence of asthma on the degree of apical root resorption in patients treated orthodontically. Methods: Sample comprised 683 patients treated orthodontically; 240 with asthma and 443 who did not present any kind of respiratory allergy or asthma. The Levander and Malmgren score was used for the evaluation of the degree of root resorption. This evaluation was performed in the initial and final periapical radiographs of the maxillary and mandibular incisors of all patients in the sample. Then, the sample was divided as follows: Group 1: 614 patients presenting mild or no root resorption with scores 0, 1 and 2, with mean initial age of 14. 37 years, final age of 16. 44 years and treatment time of 2. 07 years; group 2: 69 patients who had moderate to severe root resorption with scores 3 and 4, with mean initial age of 15. 09 years, final age of 17. 81 years and treatment time of 2. 72 years. Results: The results revealed that asthma was not a statistically significant factor for severe root resorption. The group with severe root resorption showed higher initial and final age, and longer treatment time than the group with mild root resorption. In addition, performing extractions is a risk factor for the occurrence of severe root resorption. Conclusions: Asthma is not a risk factor for the occurrence of severe root resorption after orthodontic treatment.

Background and Aim: Mineral Trioxide Aggregate (MTA) is a material used in many endodontic problems.Recently a number of studies have reported that Portland Cement (PC) and MTA have similar physical, chemical and biologic properties. In addition, a material known as root MTA which is produced in Iran has been claimed to have similar properties to Pro root MTA. If these claims are true, possible use of PC and root MTA in clinic instead of Pro root MTA will be quite cost effective. The aim of this study was to investigate the toxicity of Pro root MTA, root MTA and Portland Cement on L929 mouse fibroblasts.Materials and Methods: In this experimental study 0, 4, 24 hours and 7 days' extracts of materials were transferred to cell culture plates containing L929 fibroblasts. After 24 hours incubation, cells were stained by Neutral Red (NR), and optical density (OD) of each cell was read with ELISA reader. Data were analyzed using Tukey HSD and one way analysis of variance. P<0.05 was considered as the level of significance.Results: In all surveyed groups and negative control group, at all time points separated cells from the base of the well were round. Refraction which is a characteristic of cellular death was not observed, whereas the separated cells from the base of well in positive control group showed refractional characteristic.Conclusion: Based on the findings of this study Pro root MTA, PC and root MTA have the same biocompatibility. PC seems to have the potential to be used in the same clinical situation as MTA. However in order to replace MTA with these less expensive materials more in vitro and in vivo studies are suggested.

Background and Aim: The goal of endodontics is to seal the root canal system from the orifice to apical constriction completely and tridimensionally. Hence perforations during root canal therapy, because of caries or resorptions must be sealed and obturated with ideal materials. The aim of this study was to histologically compare two kinds of mineral trioxide aggregate root MTA and Pro root MTA for furcal perforation repair in developed teeth in dog. Materials and Methods: In this experimental study, thirty teeth consisting of second, third and fourth mandibular premolars of five German shepherd dogs were selected. Twenty-four teeth were randomly divided into four experimental groups (6 teeth each). One pair of root MTA and Pro root MTA groups studied in one month and the other in three months intervals. Positive and negative control groups was each contained three teeth. In positive control group, perforations were not treated and negative control group contained intact teeth. In experimental groups perforations repaired after one week exposure to oral cavity with root MTA or Pro root MTA. After time intervals animals were subjected to vital perfusion and 6 mm histologic sections were prepared. Inflammation and hard tissue formation were ranked by Cox criteria. Data were analysed using Mann-Whitney and Chi-Square statistical tests with P<0.05 as the limit of significance. Results: There was statistically significant lower inflammation and higher hard tissue formation in three months root MTA and Pro root MTA groups compared to one month interval (P<0.05). There was no statistically significant difference in inflammation and hard tissue formation between root MTA and Pro root MTA in each intervals (P>0.05). Conclusion: Mineral Trioxide Aggregate is an adequate material for furcal perforation repair in dog’s teeth. root MTA could be a good substitute for Pro root MTA considering the lower cost and similar characteristics.

Objective: Anesthetic techniques like the Akinosi technique were introduced to surmount the problems of the conventional inferior alveolar nerve block (IANB) technique. This study aimed to compare the local anesthetic efficacy of IANB via the conventional and Akinosi techniques in patients presenting to the Maxillofacial Surgery Department of School of Dentistry, Shahid Beheshti University.Methods: This clinical trial was conducted on 80 candidates for bilateral extraction of mandibular molars. For each patient, local anesthesia was induced by IANB injection, which was done by the conventional technique in one side and by the Akinosi technique in the other side of the mouth. The allocation of technique to side was randomized. Time to anesthesia for the long buccal, lingual and inferior alveolar nerves (IAN), degree of pain during injection and tooth extraction and incidence of positive aspiration in the two techniques were evaluated and analyzed using Wilcoxon Signed Rank and Chi square tests.Results: The mean time to anesthesia for the IAN was 2.82 minutes in the conventional and 3.05 minutes for the Akinosi technique. These values were 1.47 and 1.55 minutes, respectively for the lingual nerve and 1.43 and 1.56 minutes, respectively for the long buccal nerve. Four patients in the Akinosi technique and 12 patients in the conventional technique had positive aspiration. During anesthetic injection with the Akinosi technique, 72.5% were pain free, 18.8% experienced mild, 5% experienced moderate and 3.8% experienced severe pain. These values in the conventional technique were 51.3%, 27.5%, 11.3% and 10%, respectively.Conclusion: Considering the lack of a significant difference between the success rate of conventional and Akinosi IANB techniques, Akinosi technique seems to be a suitable alternative to the conventional technique since it is less painful and has lower risk of positive aspiration.

Background and Objective: One of the great challenges in dental practice is root perforation sealing. At present time, there are two therapeutic methods for perforation, filling and surgical removal of affected area. In this in vitro study, we compared the sealing ability of two implanted materials, Iranian domestic Mineral Trioxide Aggregate (root MTA) and foreign (Pro root MTA).Materials and Methods: In this experimental study, 58 selected maxilary and mandibular molar teeth were assigned into four experimental groups of 13 teeth and 2 groups of three teeth as control. Availability of the cavities was assessed prior to perforating of the furcal areas utilizing a No. 2 round bur. The defects were then filled using foreign MTA (Pro root) and Iranian MTA. All of the subjects were incubated for 72 hours. In the next step, nail polish was applied in two layers to the surfaces of the teeth, except for the perforation areas and coronal portions which were filled with Amalgam. Once the nail polish dried, they were placed into 2% fuchsine solution for 12 hrs. The teeth were then mesiodistally resected using 72mm disk and evaluated separately by two endodontists using a stereomicroscope with a magnification of x 20. Data were analysied by T-test and ANOVA.Results: Results indicated that there was a significant difference between the two groups regarding dye leakage (p=0.025). Pro MTA showed a lower leakage compare to Iranian MTA (root MTA).Conclusion: The quality of root MTA as a filling material may need to be improved in order to gain enough qualification as an alternative to Pro root MTA.

Statement of Problem: The major objectives of root canal treatment are removal of all irritant from the root canal space and accomplish a proper shaping of the space and total obturaion of this space. So, diagnosis of root curvature is critical and can affect on proper preparation and prevention of procedural accidents.Purpose: The aim of this study was to measure and evaluate the root curvature of permanent teeth that were treated at Endodontic Department of Shiraz Dental School (2001-2002).Materials and Methods: In this case control study, all endodontic treated patients with standardized radiographic films to determine the working length were analyzed and the angel of root curvature, were evaluated by Schneider method. After image projection and drawing of two lines, one on long axis of the canal and the other from apical foramen to the first line, the constructed angel was measured.Results: From 398 evaluated films, the root curvatures in posterior teeth were more than that in anterior teeth. Most of the roots (80%) had root curvatures directed to the mesial or distal plane although root curvatures to distal plane were more common. All of the roots had mild to moderate curvatures (0-25 degrees) except the mesial root of the first mandibular molar that had severe root curvature (more than 25 degrees). The mean of root curvature of permanent teeth were between 2.76 to 28.28 degrees.Conclusion: The results indicated that root curvatures in teeth were common and practitioners should be aware in the case of any difficulty, and refer the case to a specialist.

Background and Objectives Nowadays, most digital imaging systems offer different types of images processing techniques, considering the importance of imaging accuracy and its wide application. The aim of the current study was to comparison the effect of changing illumination on the detection of vertical root fracture in conventional digital radiography.Subjects and Methods In this ex-vivo study, the root treatment of 24 extracted anterior teeth of the patients was performed before induction of VRF (Vertical root Fracture) and radiographs were prepared. Then, after complete VRF, radiographs were taken again. To simulate the bone, the teeth were placed in a mold made of plaster and acrylic powder in an equal ratio. Gentle hammer pressure was used to create induced VRF. The images were evaluated by changing the degree of brightness (high brightness, intermediate brightness and low brightness) by 2 observers.Results Sensitivity, specificity and overall accuracy were calculated using Roc (Az) curve analysis, Kappa and MacNemar test. According to the statistical tests performed and the results obtained, the highest sensitivity, specificity and overall accuracy are related to images with high brightness and the lowest sensitivity, specificity and overall accuracy are related to images with low brightness.Conclusion Images with high brightness level have the highest sensitivity, specificity and overall accuracy, and the lowest sensitivity, specificity and overall accuracy are related to images with low brightness level. Based on the results obtained from this study, it is suggested to use radiography with high brightness in the diagnosis of vertical root fracture.