Successful conservative endodontic treatment of fused maxillary incisors: a case report

Fusion is a rare developmental dental anomaly and its definitive diagnosis is of great importance for successful endodontic treatment. A twenty-five-year old female attended the Endodontic Department with the chief complaint about dysmorphic right front tooth and a history of vague pain since the previous 11 months, which had ceased during last one month. Oral cavity examination was performed, endodontic oriented sensitivity tests including cold, hot, and electric pulp tests were conducted, and periapical radiography was also ordered. Oral cavity examination revealed an enlarged permanent right maxillary incisor with deep caries on the lingual surface. All vitality tests were negative. Examinations were normal except for one missing tooth in the total count in the upper right quadrant. Periapical radiography clarified a fused maxillary central and adjacent lateral incisor with large coronal radiolucency involving the pulp and a periapical radiolucent area suggestive of a chronic apical periodontitis. The final diagnosis was established as fused maxillary incisors with necrosis and chronic apical periodontitis. A conservative non-surgical root canal therapy was planned and careful negotiation and obturation were performed after obtaining the informed consent, followed by the esthetic reconstruction. A six month follow-up revealed that periapical radiolucency had almost disappeared, the teeth were in function, and the patient reported no complaint

[Number of severely curved root canals preparation leading to either defect or fracture using three rotary systems]

Statement of Problem: There are many controversies regarding the usable number of rotary files in the literature

Purpose: The aim of this study was to compare three Rotary Systems in Terms of Number of Severely Curved Root Canals Preparation, Till Either Defect or Fracture

Material and methods: In this in vitro study, 60 mandibular or maxillary molar mesial roots with a mature apex and a curvature of 35-80[degree sign] were evenly divided into three groups according to their radius and curvature angle. The Pruett method was used to define the curvature degree. In all the three groups, cleaning and shaping were accomplished with a working length of 16mm.Then, the number of the prepared canals until any defect or fracture [using a 8x magnifier] was recorded and canal preparation was done with the same devices in the remaining canals. Chi-square test was applied for inters categorical variables comparisons. Kaplan-Meier curves were used to display the number of prepared canals till any defect or fracture with further comparison by a log-rank test. To compare the curve angle and radius, Kruskal-Wallis test was used. p.value of less than 0.05 was considered as statistically significant

Results: The average number [+/-SD] of the prepared canals leading to defect or fracture in flexmaster, Hero and Race systems was 11.87 [+/-2.07], 13.28 [+/-2.46], and 9.66 [+/-1.92], respectively [p <0.05]. Overall, 20 devices were found to be fractured or defective, among which 7 had defects and 13 had fractures. The rates of defects in Hero, Race and Flexmaster were 50%, 33.3% and 28.6% with the fracture rate of 50%, 60% and 71.4%, respectively [p > 0.05]

Conclusion: Hero system showed higher numbers of prepared canals and revealed less fracture rate. Meanwhile, Race system revealed the least number of prepared canals with the highest rate of the fracture. However, there were no statistically significant differences between the systems

[Evaluation and comparison of apical leakage following root canal dressing with different calcium hydroxide preparations]

The use of calcium hydroxide as an intra-canal medication can lead to leakage of permanent obturation of the canal and failure of the treatment. The purpose of this study was to evaluate the rate of the remained calcium hydroxide in radiographic views and their effect on apical leakage. For this study, 75 human extracted premolar teeth were divided into 5 groups randomly. All the teeth were prepared by step back technique and apical foramen enlarged to number 30 file. Aria dent calcium hydroxide was introduced into the canal in group 1. In group 2, Barium sulfate was added to calcium hydroxide powered in 1 to 9 proportion and the methods was gone on the same as in group 1. Dentsply calcium hydroxide was mixed with glycerin-based aqueous and introduced into the canal in group 3. Calcium Hydroxide paste [Pulpdent] was introduced into the canal with its special needle. In group 4 and 5, there was no calcium hydroxide as a control group. The canals were prepared with one sixe larger than master apical file, MAF [35 file size] to remove calcium hydroxide. The remaining of calcium hydroxide was accessed radiographically and compared using Kruskal Wallis test. Dye leakage in the 5 groups was compared, using ANOVA and Tukey tests. There was no significant difference between the five groups when dye leakage was compared, but calcium hydroxide paste [Pulpdent] shows more remained material when evaluated radiographically. The use of calcium hydroxide paste with methyl cellulose base for intra-canal medicament is not recommended

[Comparison of apical leakage using AH26 and Apatite root sealers with immediate and delayed post space preparation]

Successful preparation and treatment of root canal depends on the compatibility between filling material and canal walls. On the hand, proper crown repair most often require post and core preparation. The aim of this study was to compare the effect of immediate versus delayed root canal preparation for post-space on apical seal using 2 types of sealers Apatite root sealer and AH26. This experimental study was conducted on 76 anterior teeth with single root canals. These teeth were sectioned from the cervical area which left at least 12 mm of root portion. All teeth were randomly divided into 4 groups. There were 2 positive and 2 negative control teeth aside from 15 experimental teeth in each group. After cleaning and shaping, root canals were filled with Gutta Percha, using lateral condensation method and AH26 sealer [in groups 1 and 2], and Apatite root sealer [in groups 3 and 4]. Post-spaces were immediately prepared in groups 1 and 3, leaving the last 4 mm of Gutta Percha in root canals. The root canals in groups 2 and 4 were kept in 100% moisture for a week and post-spaces were prepared with the same technique. Finally, all teeth were kept in Indian ink for 72 hours. All teeth were then demineralized in citric acid and demoisturized using ethylic alcohol. Photographs were taken from different angles using stereomicroscope connected to computer with 40x magnification in order to detect dye preparation. Photographs were evaluated by 2 independent individuals separately and dye penetration was measured. Data were analyzed using Two-Way ANOVA and Tukey tests. The immediate AH26 group had the lowest and the delayed Apatite root sealer had the highest rate of apical leakage and dye penetration. A significant difference was detected between immediate and delayed methods of post-space preparation [P<0.01]. There was no significant difference between the 2 types of sealers used [P=0.426]. Immediate post-space preparation before sealer setting had less apical leakage. No significant difference was detected between AH26 and Apatite root sealers

[Apical leakage in obturated canals using two different sealers after immediate and delayed post space preparation]

Successful endodontic therapy depends on a well-adapted filling in conjunction with root canal. The proper restoration requires the placement of a post and core. Therefore, the time of post space preparation, and its possible effect on the quality of the apical seal is important. The purpose of this study was to compare the effect of immediate and delayed post space preparations on apical seal using two currently used sealers; AH26 and Apexit sealers. Seventy six extracted anterior teeth were used in this experimental study. Teeth were randomly divided into four groups and all canals were prepared by step back method, and then filled with gutta percha by lateral condensation technique. AH26 was the sealer used in groups 1 and 2, while in groups 3 and 4 Apexit sealer was used. In groups 1 and 3, post spaces were immediately prepared. But in groups 2 and 4 they were prepared after one week. After preparation, the teeth were immersed in India ink for 3 days and finally, were cleaned. The extent of dye penetration was determined by stereomicroscope. The data were obtained and analyzed statistically with ANOVA, Tukey and T.tests. The results showed that the lowest and highest rates of dye penetration were detected in groups 1 and 4 respectively. There was significant difference in apical leakage between the AH26 immediate, and Apexit delayed post space preparation. According to the results of this study, the immediate preparation of post space after obturation and before setting of the sealer is recommended