ABSTRACT
Background: Knowledge about the anatomic variations of the root canal system and their prevalence is necessary for clinicians to ideally clean the root canal system. The anatomic complexity of the root canal system is one of the reasons for its inadequate debridement, resulting in residual microorganisms and root canal treatment failure. The present study aimed to evaluate the prevalence of middle mesial root canals in mandibular molars in an Iranian population. Materials and Methods: The samples in the present descriptive/cross-sectional study consisted of mandibular first and second molars (n = 100, with 50 first and 50 s molars). A convenient sampling method was used to collect samples. The teeth were mounted in gypsum and scanned using a micro-computed tomography unit. The images were reconstructed with software, and the relevant checklist was completed by the observers. The data were analyzed with SPSS v26 using the Chi-squared test at a significance level of P < 0.05. Results: The prevalence of the middle mesial root canal in the present study was 36% for mandibular first molars and 22% for mandibular second molars, with an overall prevalence of 29%. The prevalence of the middle mesial root canal was not significantly different between the first and second mandibular molars (P = 0.12). The mean distance between the mesiobuccal and mesiolingual root canal orifices in the teeth with a middle mesial root canal was significantly higher than in those without the middle mesial root canal (P < 0.001). In addition, there was no significant difference in the prevalence of the middle mesial root canal between the teeth with and without the second distal root canal (P = 0.89). Conclusion: The prevalence of the middle mesial root canal in the studied population was 29%, which is significant clinically. In addition, the mean distance between the mesiobuccal and mesiolingual root canal orifices in teeth with a middle mesial root canal was higher than that in teeth without this root canal.
ABSTRACT
BACKGROUND: The purpose of this study was to evaluate the prevalence of middle mesial canal in mandibular first molars using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: In this descriptive study, a total of 768 radiographs of mandibular first molars, 384 for males and 384 for females, taken at a private radiology center in Isfahan, were assessed for the presence of middle mesial canal based on the gender of the patients. All samples had been prepared by one CBCT machine. The images were evaluated by endodontists and radiologists. Then, the morphology of first molar mesial root canals was assessed by Vertucci classification, and the obtained results were analyzed by SPSS software using a Chi-square test. The comparison was considered statistically significant at P < 0.05. RESULTS: Twenty-four samples (3.13%) had a middle mesial canal. The prevalence rates of the middle mesial canal in the females and males were found to be 9 and 15 (2.35% vs. 3.92%), respectively, indicating no statistically significant difference (P = 0.21). Of 24 teeth with middle mesial canal, 17 samples (70.8%) were of Type XII and 7 samples (29.2%) were of Type VIII. There was no statistically significant difference between genders with regard to the prevalence of different types of middle mesial canals (P = 0.19). CONCLUSION: The prevalence of the middle mesial canal was rather low in this study, and it is necessary to detect additional canals in the patients under root canal treatment.
ABSTRACT
BACKGROUND: Antibacterial activity is one of the important characteristics of an ideal root canal sealer. The aim of this study was to investigate the antibacterial activity of five different sealers against Enterococcus faecalis using two different methods. MATERIALS AND METHODS: The mineral trioxide aggregate (MTA) Fillapex, Tg-sealer, Endomethasone, AH-26, and RoekoSeal sealers were placed into the brain heart infusion (BHI) culture medium containing E. faecalis (PTCC1393). The diameter of the bacterial zone of inhibition was measured. In the direct contact test, a suspension containing grinded set sealers and E. faecalis bacteria was cultured in BHI after 6, 15, and 60 min. The number of colonies in milliliter was calculated. Data were subjected to one-way ANOVA and Tukey's multiple comparisons test (P < 0.05). RESULTS: In the agar diffusion test, Endomethasone had the highest antibacterial activity against E. faecalis compared to other sealers (P < 0.001). In the direct test, the antibacterial effect of MTA Fillapex was significantly higher than that of all other sealers (P < 0.001). CONCLUSION: The technique and components of the tested sealers affect the antibacterial activity results. This study showed that all of sealers had antimicrobial effect.
ABSTRACT
INTRODUCTION: Sealing ability is an important factor for a root-end filling material in endodontic surgeries. This in vitro study aimed to compare the sealing ability of mineral trioxide aggregate (MTA) and a new endodontic cement named calcium enriched mixture (CEM) cement as root-end filling materials. MATERIALS AND METHODS: The experiments were carried out in dry, saliva or blood contaminated root-end cavities of hundred single-rooted extracted human teeth. After decoronation, the root canals were cleaned, shaped, obturated, and stored in 100% humidity for 5 days. Removing the apical 2-3mm of each root, a 3mm deep root-end cavity was ultrasonically prepared. Samples were randomly divided into 2 test groups of 45 roots/experimental material, and one subgroup (n=15) for each environmental condition as follows; a) dried before placing the filling material, b) filled after contamination with saliva, and c) filled after contamination with blood. Ten roots were used as positive/negative controls. Samples were placed in an incubator at 37°C for a day and immersed in methylene blue dye under reduced pressure environment for 48hours. Roots were sectioned longitudinally and examined under stereomicroscope by an independent observer. RESULTS: Using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction, the results demonstrated significantly less leakage for the CEM cement in saliva contaminated condition when compared to MTA (P<0.001). CONCLUSION: It can be concluded that the sealing ability of CEM cement was superior to MTA in saliva contaminated condition.
