Bilateral Presence of Two Distobuccal Canals in Maxillary First Molars: A Case Report

This article describes the diagnosis and treatment of bilaterally maxillary first molars with two canals in their distobuccal roots. A 13-year-old male came to the clinic with a severe pain of tooth #14. In the first session, after access and finding the main canals and the second mesio-buccal (MB2) canal, another canal was noticed in the distobuccal root. All teeth were examined and a severe decay was observed in the left maxillary first molar. After preparing the access cavity, another orifice was found between the palatal and distobuccal canals. The presence of the second distobuccal canal was confirmed using an apex locator and radiography.Keywords: Anatomic Variation; Maxillary First Molar; Root Canal System; Second Distobuccal Canal

Endodontic Treatment of a Maxillary Lateral Incisor with Two Canals: A Case Report

Variations in the number of roots and canals have been extensively reported in endodontic literature. One rare variation is presence of two separate root canals in maxillary lateral incisors. This study reports a maxillary lateral incisor with two canals. Although rare, knowledge about this anatomical variation can help in successful endodontic treatment of such teeth.Keywords: Anatomic Variation; Root Canal; Tooth Abnormalitie

Evaluation of Cytotoxic Effects of Various Endodontic Irrigation Solutions on the Survival of Stem Cell of Human Apical Papilla

Introduction: Root canal disinfection is an important step in regenerative endodontic treatments. An ideal irrigating solution must have high antimicrobial activity and minimum cytotoxicity. This study sought to assess the effect of some irrigating solutions on stem cells from the human apical papilla (SCAP) after different periods of exposure. Methods and Materials: Stem cells were isolated from immature, impacted mandibular third molars, transferred to 24-well plates, randomly divided into 6  experimental groups and exposed to BioPure MTAD Cleanser, QMix, 17% EDTA, 2% chlorhexidine (CHX), 5.25% sodium hypochlorite (NaOCl), sterile saline and untreated control group. Cytotoxicity of these solutions was assessed after 1, 5 and 15 min of exposure using the methyl thiazol tetrazolium (MTT) assay. Data were statistically analyzed using repeated measures ANOVA. Level of significance was set at 0.05. Results: The mean percentage of viable cells in all experimental groups was significantly different from the control and sterile saline groups at all the time points (P<0.0001). The mean percentage of viable cells significantly decreased over time in NaOCl, QMix, EDTA and MTAD groups, but no significant reduction was noted in CHX group. At all the time points the highest and the lowest cytotoxicity were seen in MTAD and normal saline groups, respectively. Cytotoxicity of the understudy materials from the highest to the lowest was as follows: MTAD>EDTA>QMax=NaOCl>CHX> sterile saline. Conclusion: Chlorhexidine had the lowest cytotoxicity compared to EDTA, MTAD, QMix and NaOCl and its cytotoxicity did not change over time compared to other solutions.Keywords: Apical Papilla; Cytotoxicity; Irrigating Solution; MTT Assay; Stem Cell

The effect of different irrigants and intra canal dressing on sinus tract closure

Introduction: Antimicrobial activity of irrigants and interappointment intracanal dressing is an important consideration in endodontics. The aim of this study was to evaluate the clinical efficacy of chemomechanical preparation of the necrotic canals with different irrigants and intra canal dressing in the control of root canal infection and sinus tract closure. Materials &Methods: In this study, 65 patients with sinus tract were treated. They were randomly divided into 4 groups. Sodium hypochlorite (NaOCl) and chlorhexidine (CHX) was used as the irrigation solutions in the group one and two, then the canals were filled. In group three, after irrigation with NaOCl, Ca (OH) 2/sterile Saline was used as intra canal medicament, and similar to group three Ca (OH) 2/CHX was used in group four after irrigating by CHX. After 7 days, the intra canal paste was removed and the canals were filled. The sinus tract closure was followed up within 7, 14, and 21-day intervals. The data were analyzed using Chi Square and Kruskal-Wallis statistical tests. Results: The highest mean time of sinus tract closure was for Ca (OH)2/sterile Saline and the lowest was for Ca(OH)2/CHX. The differences of sinus tract closure between group 2&4 (p=0.04), group 3&4 (p=0.004). Groups were statistically significant. Conclusion: It was concluded that Ca (OH)2/CHX paste as intra canal dressing has good clinical efficacy in the control of root canal infection and sinus tract closure

In-vitro Comparison of NiTi Tee, RaCe and Protaper Instruments in Dentinal Crack Formation

Background and Aim:Root canal preparation with rotary instruments may cause dentinal cracks leading to tooth fracture. The aim of this study was to compare three different rotary systems ProTaper, RaCe and Niti Tee on formation of dentinal cracks following root canal preparation. Materials and Methods: In this experimental study, 50 extracted mandibular first molars were selected. Teeth having roots with previous cracks and defects were excluded from the study. The crowns and distal roots of teeth were cut. Silicon impression material was used to simulate tooth PDL. The mesial roots were randomly prepared using ProTaper (up to F3) RaCe and Niti Tee systems (up to ≠30/0.06) in three groups of 15. Five teeth remained unprepared as the control group. The specimens were then sectioned horizontally in 3, 5 and 9 mm distances from the apex. Cracks exploration was done by digital stereomicroscope. The occurrence of dentinal cracks with different systems were statistically analyzed by chi-square test. Results: Dentinal defects were observed in 3 (20%), 4 (26.7%) and 2 (13.3) of root canals following the preparation with ProTaper, Niti Tee and RaCe files, respectively. Two of the 3 defects in protaper group were as complete crack. The overall incidence of crack among the rotary files was 20%. No significant differences were found in defect formation between the three rotary systems (P>0.05).  Conclusion: Under the condituion of this study Dentinal cracks were observed in all systems. The overall incidence of crack among the rotary files was 20%. Although more cracks were observed in NTiTee group, the differences were not significant

Analysis of methylation and mRNA expression status of FADD and FAS genes in patients with oral squamous cell carcinoma

Background: Apoptosis is an important mechanism that is responsible for the physiological deletion of harmful, damaged, or unwanted cells. Changed expression of apoptosis-related genes may lead to abnormal cell proliferation and finally to tumorigenesis. Our aims were to analyze the promoter methylation and gene expression profiles of FADD and FAS genes in risk of OSCC. Material and Methods: we analyze the promoter methylation status of FADD and FAS genes using Methylation - Specific PCR (MSP) in 86 OSCC tissues were kept in paraffin and 68 normal oral tissues applied as control. Also, FADD and FAS genes expression were analyzed in 19 cases and 20 normal specimens by Real-Time Reverse- Transcripts PCR. Results: Aberrant promoter methylation of FADD and FAS genes were detected in 12.79 % (11 of 86) and 60.46 % (52 of 86) of the OSCC cases, respectively, with a significant difference between cases and healthy controls for both FADD and FAS genes ( P <0.001). The gene expression analysis showed statistically significant difference between cases and healthy controls for both FADD ( p <0.02) and FAS ( p <0.007) genes. Conclusions: To the best our knowledge, the data of this study are the first report regarding, the effect of promoter hypermethylation of the FADD and FAS genes in development of OSCC. To confirm the data, it is recommended doing further study in large sample sizes in various genetic populations

Location of mental foramen in a southeast iranian population: a digital panoramic assessment

Introduction: Mental foramen is an important landmark in mandible and knowledge regarding the actual location of mental foramen is important in dentistry. Materials &Methods: A total of 1172 digital panoramic radiographs were evaluated for assessment of the location of the mental foramen. The location was classified into six groups in relation to the apices of the premolars and first molar. Results: In 957 of panoramic radiographs, fulfilling the inclusion criteria, the most common location of the mental foramen was at the apex of the mandibular second premolar. In 837 cases (87.5%), the mental foramen was located symmetrically on both sides of the mandible. Therefore, the apex of the second premolar was the most common symmetric location in both genders. Conclusion: The results showed that the most common location of the mental foramen in population of southeast Iran was at the apex of the second premolar

Detection of Carious Lesions and Restorations Using Particle Swarm Optimization Algorithm

Background/Purpose. In terms of the detection of tooth diagnosis, no intelligent detection has been done up till now. Dentists just look at images and then they can detect the diagnosis position in tooth based on their experiences. Using new technologies, scientists will implement detection and repair of tooth diagnosis intelligently. In this paper, we have introduced one intelligent method for detection using particle swarm optimization (PSO) and our mathematical formulation. This method was applied to 2D special images. Using developing of our method, we can detect tooth diagnosis for all of 2D and 3D images. Materials and Methods. In recent years, it is possible to implement intelligent processing of images by high efficiency optimization algorithms in many applications especially for detection of dental caries and restoration without human intervention. In the present work, we explain PSO algorithm with our detection formula for detection of dental caries and restoration. Also image processing helped us to implement our method. And to do so, pictures taken by digital radiography systems of tooth are used. Results and Conclusion. We implement some mathematics formula for fitness of PSO. Our results show that this method can detect dental caries and restoration in digital radiography pictures with the good convergence. In fact, the error rate of this method was 8%, so that it can be implemented for detection of dental caries and restoration. Using some parameters, it is possible that the error rate can be even reduced below 0.5%

Comparative Evaluation of Root Canal Transportation by Three NiTi Single-File Systems in Curved Canals: A Cone Beam Computed Tomography Study

Introduction. This study is aimed at evaluating root canal transportation in the mesiobuccal canal of mandibular first molars prepared with One Shape, Reciproc, and M-One nickel titanium (NiTi) single-file rotary systems using cone beam computed tomography (CBCT). Materials and Methods. In this ex vivo study, CBCT scans of 45 extracted human mandibular first molars with 20–40° curvature were obtained. The teeth were randomly divided into three groups (n=15) for preparation of the mesiobuccal canal with One Shape, Reciproc, and M-One rotary systems according to the manufacturers’ instructions. CBCT scans were obtained again after canal preparation. Changes caused by preparation in the coronal, middle, and apical thirds were determined on CBCT scans and analyzed using the Kruskal–Wallis test at P≤0.05 level of significance. Results. No significant difference was noted in the amount of canal transportation among the three groups (P>0.05). M-One caused greater transportation in the apical third compared with Reciproc and One Shape, and One Shape caused greater transportation in the coronal third compared with other groups, although its magnitude was less than 0.3 mm. Conclusion. Reciproc, One Shape, and M-One are not significantly different in terms of canal transportation

Detection of Carious Lesions and Restorations Using Particle Swarm Optimization Algorithm

Background/Purpose. In terms of the detection of tooth diagnosis, no intelligent detection has been done up till now. Dentists just look at images and then they can detect the diagnosis position in tooth based on their experiences. Using new technologies, scientists will implement detection and repair of tooth diagnosis intelligently. In this paper, we have introduced one intelligent method for detection using particle swarm optimization (PSO) and our mathematical formulation. This method was applied to 2D special images. Using developing of our method, we can detect tooth diagnosis for all of 2D and 3D images. Materials and Methods. In recent years, it is possible to implement intelligent processing of images by high efficiency optimization algorithms in many applications especially for detection of dental caries and restoration without human intervention. In the present work, we explain PSO algorithm with our detection formula for detection of dental caries and restoration. Also image processing helped us to implement our method. And to do so, pictures taken by digital radiography systems of tooth are used. Results and Conclusion. We implement some mathematics formula for fitness of PSO. Our results show that this method can detect dental caries and restoration in digital radiography pictures with the good convergence. In fact, the error rate of this method was 8%, so that it can be implemented for detection of dental caries and restoration. Using some parameters, it is possible that the error rate can be even reduced below 0.5%