Antibacterial effect of nano-chlorhexidine on Enterococcus faecalis biofilm in root canal system: An in vitro study.

Background: A new method to improve the properties of the materials is nano-encapsulation, which improves the biological properties, antibacterial activity along with reduction of toxicity. Due to the spread of nano-knowledge, the present study was performed to evaluate the antibacterial effect of nano-chlorhexidine (CHX) on Enterococcus faecalis biofilm in the root canal system. Materials and Methods: In this in vitro experimental study, 55 matured single-root mandibular premolars were decoronated and the canals were prepared by single length method up to #F3 ProTaper Universal system. Five teeth were selected as negative control. Then, the teeth were randomly divided into three experimental groups (n = 15) and a positive control group (n = 5). The experimental groups were irrigated with 2% nano- CHX gel, 2% CHX solution, and 5.25% sodium hypochlorite (NaOCl), respectively. Finally, the number of colonies was counted. Kruskal-Wallis test was used to compare the number of colonies among groups. The level of significance was set at P < 0.05. Results: The mean number of colonies in the groups of nano-CHX, NaOCl, CHX, and positive control were obtained as 17.73 ± 18.69, 35.53 ± 36.42, 38.8 ± 31.8, and 96.8 ± 22.52, respectively. There was a significant decrease in the number of colonies in all the experimental groups compared to the control group (P < 0.05). However, difference in the number of colonies among these three groups was not significant (P > 0.05). Conclusion: The use of nano-CHX in removing E. faecalis biofilm from root canal is as effective as the use of CHX and NaOCl.

Pattern of Endodontic Lesions of Maxillary and Mandibular Posterior Teeth: A Cone-Beam Computed Tomography Study.

The pattern of expansion of endodontic lesions in the jaws has been less commonly addressed in the literature. For this reason, the aim of this study is to assess the pattern of endodontic lesions of maxillary and mandibular posterior teeth using cone-beam computed tomography (CBCT). This cross-sectional study was conducted on 317 endodontic lesions of posterior teeth on CBCT scans retrieved from a radiology center in Qazvin, Iran, from 2020 to 2022. Endodontic lesions were assessed on sagittal, coronal, and axial sections by an endodontist and dental student using the Romexis software. The largest lesion diameter was measured occluso-apically, mesiodistally, and buccolingually. Lesion size was analyzed based on age, gender, jaw, tooth type, and presence/absence of root filling by independent samples t-tests and a one-way Analysis Of Variannce (ANOVA). The largest diameter of lesions in the maxilla and mandible was recorded in the occluso-apical dimension followed by buccolingual and mesiodistal dimensions (p > 0.05). The pattern of lesions was the same in teeth with and without endodontic treatment, but it was significantly different in maxillary and mandibular endodontically treated teeth in the occluso-apical and buccolingual dimensions (p < 0.05). No significant correlation was noted with tooth type or jaw except for maxillary and mandibular first molar lesions, which were significantly different in the occluso-apical dimension (p < 0.05). Lesion size in all three dimensions was significantly greater in males than females (p < 0.05), and was the highest in the occluso-apical dimension in both genders. In the maxilla, the mean lesion size significantly decreased in the mesiodistal dimension with age (p < 0.05). In conclusion, the largest lesion diameter in the maxilla and mandible was found in the occluso-apical dimension, indicating the role of bone density in the pattern of lesions.

Comparison of the effect of post space preparation time on the apical seal of two different sealers.

BACKGROUND: The present study compared the effect of post space preparation time on the apical seal of two different sealers. METHODS: In the in vitro study, 94 central incisors were used. After the samples' root canal preparation, they were randomly assigned to four experimental groups (n = 21). The samples in groups 1 and 2 were obturated with AH Plus sealer, gutta-percha, and in groups 3 and 4 with Endoseal MTA bioceramic sealer and single cone technique. The post spaces in groups 1 and 3 were prepared immediately and in groups 2 and 4 with a delay. The samples were evaluated at 7-, 30-, and 90-day intervals for apical microleakage using the fluid filtration technique. The data were analyzed with SPSS 25, using three-way ANOVA and independent t-test. RESULTS: The apical microleakage in groups 3 and 4, obturated with Endoseal MTA bioceramic sealer and prepared immediately and after a delay, respectively, was not significantly different between the interval times. In group 2, obturated with AH Plus sealer and prepared for post space with a delay, the apical microleakage was significantly less than all the other groups. Group 1, obturated with AH Plus sealer and prepared for post space immediately, exhibited the least microleakage after seven days, but its microleakage increased over time to reach the level of groups 3 and 4. CONCLUSION: According to the results, the apical microleakage in the AH + sealer group and the delayed post-space preparation method, was significantly less than all the other groups over time.

Management of a complex traumatic dental injury: Crown, crown-root, and root fracture.

Dental trauma can result in different kinds of injuries based on the extent, direction, and location of the impact. Multidisciplinary management of traumatized teeth is critical for successful treatment and improvement of the prognosis.

Revascularization and vital pulp therapy in immature molars with necrotic pulp and irreversible pulpitis: A case report with two-year follow-up.

Management of teeth with inflamed pulp has been always a challenge. Revascularization and vital pulp therapy are suggested as procedures for successful treatment of immature molars diagnosed with pulp necrosis and irreversible pulpitis, respectively.

Cone-Beam Computed Tomographic Evaluation of Artifact Effects of Three Different Sealers.

Introduction: Cone-beam computed tomography (CBCT) is one of the most important diagnostic tools in maxillofacial imaging. Nowadays different sealers are used in root canal therapy and some of them can create artifact in CBCT images. The aim of this study was to evaluate the effect of different sealers including AH-26, Diadent, and Anyseal in creation of artifact bands in the CBCT images based on voxel size. Methods and Materials: A total of 44 single rooted extracted teeth were selected. The canals were prepared by crown-down technique. All teeth were manually filed up to master apical file (MAF) size 45 and 1 mm shorter than the apical foramen. The teeth were divided into 4 equal groups. The canals were filled with gutta-percha and either of sealers AH-26, Diadent or Anyseal by lateral condensation technique. The control group were filled just with gutta-percha without any sealer. The CBCT images were taken in voxel sizes of 0.3 and 0.15. The Fisher exact and McNemar tests were used for statistical analysis. Results: Although, the control group had the lowest ratio of presence to absence of artifact, the ratio of presence to absence of artifact in voxel size of 0.3 and 0.15 mm were significantly lower in Anyseal than AH-26 (P=0.031, P=0.020) and Diadent (P=0.001, P=0.002). No significant difference was detected between two voxel sizes (P>0.05). Conclusion: In this in vitro study, all evaluated sealers induced artifacts in the CBCT images. Anyseal sealer had the lowest artifact in both evaluated voxel sizes.

Evaluation of Root Canal Morphology of Mandibular First and Second Premolars Using Cone Beam Computed Tomography in a Defined Group of Dental Patients in Iran.

BACKGROUND: Successful dental root canal treatments require a complete knowledge of dental anatomy and root canal morphology. MATERIALS AND METHODS: One hundred and forty-five cone beam computed tomography (CBCT) images were used to assess the anatomy and morphology of mandibular premolars based on Vertucci's classifications in a defined group of dental patients in Iran. The number of roots and root canals, root canal morphology, root and canal shape (curvature), existence of C-shaped canal, and influence of sex on each of these were evaluated. A chi-squared test was used for statistical analysis. RESULTS: The mandibular first and second premolars had a single root in 95.97% and 100% cases, respectively. In the mandibular first premolars, 62.2% were of type I, 0.8% type II, 10.9% type III, 0.8% type IV, 20.3% type V, 4.2% type VI, and 0.8% type VII; in the second premolars, 78% of canals were of type I, 3% type II, 11% type III, 7% type V, and 1% type VI. C-shaped canals did not exist in either of the premolars. The most prevalent root and canal shape was straight. The most prevalent root curvature was a distal curvature in both premolars (71.4% and 74% of first and second premolars, resp.). The most prevalent canal curvature was lingual and buccal for the first premolars (7.6% each) and distal for the second premolars (11%). No significant difference was found between men and women in nearly all of the above (P > 0.05). CONCLUSION: The results suggest that there is a need to conduct further evaluations on finding root and canal variations among more populations to gain better knowledge prior to root canal treatment.