Iranian Endodontic Journal
Year:2006 | Volume:1 | Issue:4|Papers Count:9

Introduction: This investigation evaluates the effects of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and calcium enriched mixture (CEM) as pulp capping materials on dental pulp tissues.Materials and Methods: The experimental procedures were performed on eighteen intact dog canine teeth. The pulps were exposed. Cavities were randomly filled with CEM, MTA, or CH followed by glass ionomer filling. After 2 months, animals were sacrificed, each tooth was sectioned into halves, and the interface between each capping material and pulp tissue was evaluated by scanning electron microscope (SEM) in profile view of the specimens. Mann-Whitney test was used for statistical analysis.Results: Dentinal bridge formation as the most characteristic reaction was resulted from SEM observation in all examined groups. Odontoblast-like cells were formed and create dens collagen network, which was calcified gradually by deposition of calcosphirit structures to form newly dentinal bridge No significant difference was detected between studied groups.Conclusion: Based on the results of this in vivo study, it was concluded that these test materials are able to produce calcified tissue in underlying pulp in the case of being used as a pulp capping agent. Additionally, it appears that CEM has the potential to be used as a direct pulp capping material during vital pulp therapy.

Introduction: The aim of this study was to compare a clearing technique with conventional radiography in studying certain features of the root canal system in single root premolars. A secondary aim was to assess inter examiner agreement for these features using radiographs.Materials and Methods: Fifty-eight recently extracted single rooted premolars were included in this study. Two standard periodical radiographs were taken from buccolingual and 20o direction. The specimens were then decoronated, demineralized in 10% hydrochloric acid for 24 hours and then were cleared using methylsalicylate. The cleared teeth were examined using a magnifier (x10) and data relating to number of roots, canals, apical foramina and their positions were collected. The radiographs were examined by two independent trained endodontists using an X-ray viewer and the magnifying lens for same studied features using the clearing technique.Results: The kappa values for the agreement between the clearing technique and two examiners for the number of canals in standard radiographs were k=0.07, k=0.26 and in angulated radiographs were k=0.84, k=0.39 and k=0.31; for number of apical foramen were k=0.66, k=0.50, and k=0.19 and for detection the number of roots were %84 and %92 for examiner 1 and %92 and %88 for examiner 2.Conclusion: In general, the kappa values were low to moderate for all comparisons. It is concluded that agreement between either radiographic examiners and clearing technique were poor to moderate indicating the limited value of radiographs alone at the time of studying certain aspects of the root canal system.

Introduction: The aim of this study was to compare the efficacy of two irrigants on decreasing the pain and swelling at different times after treatment of necrotic pulp.Materials and Methods: Fifty patients with single canal tooth and necrotic pulp were selected and divided into two groups, twenty-five in each. Rotary files were used for preparing the canals and 0.2% chlorhexidine gluconate and 2.5% sodium hypochlorite were used for irrigation of canals. Then canals were filled by lateral condensation technique. A questionnaire was given to patients asking for the level of their pain and swelling. The patients were followed for 48h. Visual Analogue Scale (VAS) was used for determination of pain degree. The scale with 4 levels was used for measurement of the intensity of swelling. The data were statistically analyzed using Mann-Witney and Kruskal-Wallis tests.Results: The research showed no significant difference between irrigant solutions in decreasing the amount of pain and swelling after endodontic treatments. No significant relationship was detected between the incidence of pain with swelling, age, and sex. Flare-up in maxilla was more than mandible.Conclusion: According to results of this in vivo study it was concluded that efficacies of 0.2% chlorhexidine gluconate and 2.5% Nacl are the same.

Introduction: The aim of this study was to determine the effect of different luting agents on fracture resistance of endodontically treated teeth restored with casting post.Materials and Methods: In this experimental study, forty extracted human maxillary central incisors teeth with the mean length of 23mm were randomly assigned in to four groups. All the studied teeth were caries free without any crack. After root canal treatment, the specimens were stored in 100% relative humidity at 37°C for 72h, and were decoronated 2mm above cement enamel junction. The teeth in group 1, 2, 3, and 4 received casting post and core and they were cemented with Zinc phosphate, Panavia F, Fuji Glass Ionomer, and Rely X, respectively. All teeth received 1.5 mm shoulder finishing line and 0.5mm bevel.Samples were then restored with complete coverage crowns and were loaded with an Instron universal testing machine. The cross-head speed was 0/02 cm/min and specimens were loaded with load values (Newton) computed at a speed of 1000 point/min, until the fracture happened. Loads were applied with 135 degree at middle lingual surfaces of the samples.Fracture loads were recorded. Data were analyzed by the one-way ANOVA test.Results: There was no significant difference between the fracture resistances of four test groups.Conclusion: According to the results of this in vitro study, the type of luting cement had no influence on the fracture resistance of teeth.

Introduction: Candida Albicans (CA) is by far the most common yeast of oral infections, including endodontic infections. The aim of this study was to evaluate and compare the antifungal effect of white-colored mineral trioxide aggregate (WMTA) and Portland Cement (PC) using a tube-dilution test.Materials and Methods: WMTA and PC were tested freshly mixed and after 24 h. The experiment was performed in 24-well culture plates. Fifty wells were used and divided into four experimental groups (freshly-mixed WMT Afreshly-mixed PC, 24 h-set WMTA, and 24 h-set PC) of 10 wells each and control groups of five wells each. Plates of Sabouraud dextrose agar mixed with CA served as positive control and Sabouraud dextrose agar without CA served as negative control. Fresh inoculate of CA was prepared by growing an overnight culture from a stock culture. Aliquots of CA were then taken from the stock culture and plated on the agar compound of the experimental and control groups. All plates were incubated at 37°C for in, 24 h, and 72 h. Growth of fungi was monitored daily by the presence of turbidity. Kruskal-Wallis test was used for data analysis.Results: Findings showed that in the freshly mixed as well as 24 h-set WMTA and PC, fungal growth was observed during 1h incubation; where as by increasing the incubation time, no fungal growth was observed in 24 h and 72 h.Conclusion: It was concluded that WMTA and PC (freshly mixed and 24-h set) were effective against CA.

Introduction: Recently, attention has been drawn to the influence of smear layer removal on apical seal, and the relation of root canal filling material with canal wall surface in the presence and absence of the smear layer. The purpose of this study was to evaluate the influence of the smear layer removal on the apical sealing ability of AH26 sealer.Materials and Methods: Forty extracted human anterior teeth were used in this study.All teeth were decoronated at CEJ. Root canals were prepared; and before obturation, they were randomly divided into two groups (n=17): Group A in which the smear layer was left intact, and in Group B smear layer was removed. Six roots were served as controls. After obturation, micro leakage was measured by the electrochemical method for 30 days with 3-day intervals. Data were then analyzed by using Mann-Whitney test.Results: Based on the results of this study, in the absence of the smear layer, a highly significant decrease of apical leakage was found (P<0.001).Conclusion: This study showed that the removal of the smear layer can significantly improve the apical sealing ability of AH26 sealer.

Introduction: Apexogenesis is a way to save vitality of open apex damaged teeth with mild or moderate pulp involvement. Such teeth are not repaired through normal and usual treatments. This treatment provides usual and physiological conditions for root to develop in normal length. The aim of this study was to determine the success rate of apex genesis according to the duration of pulp exposure.Materials and Methods: In this animal study, mineral trioxide aggregate (MTA) and calcium hydroxide (CH) were used. The examined teeth were canines of cats with open apices. The treatment was accomplished in three periods of 1, 3, and 6 weeks after pulpal exposure. Four months later, the results were evaluated histologically and radio graphically.Results: The results showed no significant difference between the success rate of MTA and CH. Besides, after 6 weeks of pulpal exposure the treatment was successful. Root development and apical closure was detected in approximately 42% of teeth, while 33% of samples had a healthy Hertwig's sheath.Conclusion: The findings of this study suggested that the conservative treatment in traumatized teeth after 1.5 month of pulpal exposure could be successful.

This report presents a case of 10 years old girl who was referred to the pediatric dentistry clinic sustaining a sever trauma led to crown fracture and intrusive luxation of immature maxillary incisors. Antibiotic therapies were initiated at first visit, and after surgical exposure both intruded and extruded teeth were endodontically treated by calcium hydroxide.Orthodontic repositioning was performed and root canal filling with gutta-percha was accomplished. Six years after orthodontic repositioning, clinical and radio graphical examinations revealed satisfactory apical and periodontal conditions.

Introduction: The effectiveness of low power lasers for incisional wound healing, because of conflicting results of previous research studies, is uncertain. Therefore, this study was carried out to evaluate low power laser effects on incisional wound healing.Materials and Methods: Incisional wound was produced on thirty-six mature male guinea pigs under general and local anesthesia. In half of the cases, He-Ne laser radiations were used for five minutes and the rest were left untreated. Animals were divided into six groups of six animals each that were killed after 3, 5 and 14 days. After histopathology processing and H&E staining, specimens were examined for acute and chronic inflammations, epithelial cell migration, epithelial seal and barrier formation, fibroblast migration, fibrosis, clot formation and granulation tissue formation. Mann-Whitney U and the Wilcoxon tests were used for statistical analysis.Results: Statistically significant differences were found between fibroblast migration, acute and chronic inflammation of radiated groups and the control group at 5 days interval (p<0.05). There was no statistically significant difference at 3 and 14 days between laser radiated and control groups.Conclusion: This study showed that He-Ne laser had beneficial effects on incisional wound healing particularly at 5 days interval; however, further research on chronic ulcers is recommended.