Comparative evaluation of pericervical dentin preservation and fracture resistance of root canal-treated teeth with rotary endodontic file systems of different types of taper - An in vitro study.

Aims: The aim of this study was to evaluate and compare the pericervical dentin preservation and fracture resistance of root canal-treated teeth with rotary endodontic file systems of different types of taper. Subjects and Methods: Thirty-two single-rooted human-extracted premolars were used. They were mounted in wax, and preoperative cone-beam computed tomography (CBCT) scans were taken with 11 × 8 Field of view (FOV). The evaluation of the pericervical dentin thickness was done at the cementoenamel junction level. After pre-CBCT, the 32 samples were divided into four groups (n = 8) - Group A: fixed tapered hand files, Group B: variable regressive tapered TruNatomy, Group C: progressive tapered ProTaper Gold, and Group D: fixed tapered HyFlex EDM. Following instrumentation, postoperative CBCT scans were taken to evaluate pericervical dentin thickness. Obturation was done and access cavity was restored with composite. Fracture strength was checked for all the samples using "universal testing machine" until fracture, and calculated in newtons (N). Statistical Analysis Used: Student's t-test and ANOVA test, along with Tukey's post hoc analysis, were used for comparing mean values between the groups, and P < 0.05 was considered statistically significant. Results: The results of this study showed that there is no statistically significant difference in preserving pericervical dentin with file system of different types of taper and fracture resistance between the groups. Conclusions: Within the limitations of the study, it was concluded that different types of file taper systems used for root canal preparation have no significant effect on the preservation of pericervical dentin and fracture resistance of teeth.

Comparative evaluation of genotoxicity and cytotoxicity of flowable, bulk-fill flowable, and nanohybrid composites in human gingival cells using cytome assay: An in vivo study.

Context: Biocompatibility is one of the major prerequisites for safe clinical application of materials. Resin composites release their components into oral environment following restoration which cause adverse reactions. Aims: To evaluate and compare the genotoxicity and cytotoxicity of flowable, bulk-fill flowable, and nanohybrid composites with glass ionomer cement in human gingival cells using epithelial-based cytome assay. Methodology: Sixty healthy patients with noncarious cervical lesions were selected and randomly assigned to four groups (n = 15): Group A, glass ionomer cement; Group B, flowable composite; Group C, bulk-fill flowable composite; and Group D, nanohybrid composite. Class V restorations were done in each group with the respective restorative materials. Samples of epithelial cells were collected from gingiva before (control) (T1) and after 10 and 30 days (T2 and T3) postrestoration and examined for the presence of micronuclei and other nuclear anomalies. Statistical Analysis Used: The results were subjected to statistical analysis using Friedman's test and Kruskal-Wallis test. Results: The highest level of cytotoxicity was noted at T2 time point with a significant decline at T3 time point. Least cytotoxic damage was exhibited by Group A followed by Group D. Highest cytotoxic effect was shown by Group B followed by Group C. There was no significant level of genotoxicity induced by any of the materials tested at different time points. Conclusion: There is significant cytotoxicity induced by the tested composite materials which had no long-term effects and no genotoxicity was induced by any of the restorative materials tested.

Canal transportation and centering ability of root canals prepared using rotary and reciprocating systems with and without PathFiles in cone-beam computed tomography-based three-dimensional molar prototypes.

BACKGROUND: It is important to use instruments that cause minimal changes in the canal path for root canal preparation. There is inadequate literature comparing rotary and reciprocating systems and hand files. No study used three-dimensional printed models to compare rotary, reciprocating, and hand files. AIMS: We aimed to assess the canal transportation and centering ability of WaveOne Gold, ProTaper Gold, and NiTi Flex K-file systems with and without glide path preparation. MATERIAL AND METHODS: Forty-nine resin models were randomly divided into Group I A - WaveOne Gold with WaveOne Gold Glider and Group I B - WaveOne Gold without glide path; Group II A - ProTaper Gold with ProGlider and Group II B - ProTaper Gold without glide path; and Group III A - NiTi Flex K-files with no. 10 stainless steel K-file and Group III B - NiTi Flex K-files without glide path. Pre- and postinstrumentation cross-sectional images at levels 3, 5, 7, 9, and 11 mm were compared. RESULTS: WaveOne Gold caused the least canal transportation and improved centering ability (P < 0.05). NiTi Flex K-files transported the canal more than others in the apical levels (3, 5 mm). Glide path creation reduced canal transportation and improved canal-centering ability. CONCLUSIONS: WaveOne Gold system has better centering ability and lesser canal transportation than ProTaper Gold and NiTi Flex K-file. Glide path creation reduced canal transportation and improved canal-centering ability.

Comparative Evaluation of Casein Phosphopeptide-Amorphous Calcium Phosphate-Fluoride Paste and Sodium Fluoride Mouthwash in the Prevention of Dental Erosion: An In Vitro Study.

AIM: To compare the efficacy of casein phosphopeptide-amorphous calcium phosphate-fluoride (CPP-ACP-F) paste and 0.2% sodium fluoride mouthwash in the prevention of dental erosion using profilometer. MATERIALS AND METHODS: The buccal surfaces of 36 premolar sound teeth were ground and polished to achieve a flat surface with silicone disks. Samples were allocated in three groups randomly. Group I was pretreated for 5 days four times a day with CPP-ACP-F paste. Group II was pretreated for 5 days with 0.2% sodium fluoride mouthwash four times a day. Group III remained as the control group without any pretreatment. In the next step, all the samples were exposed four times a day for 3 days to carbonated beverages. The samples were rinsed with saline after each erosive cycle and stored in artificial saliva. The profilometer was used to determine the surface loss. The data collected were evaluated using one-way analysis of variance (ANOVA) along with post hoc test. RESULTS: The erosion of group I (CPP-ACP-F paste) and group II (0.2% sodium fluoride mouthwash) was significantly less than that of group III (control group). The erosion in group II was significantly lower than in group I. CONCLUSION: Both sodium fluoride mouthwash and CPP-ACP-F paste are effective in the prevention of dental erosion. Sodium fluoride mouthwash shows higher reduction in dental erosion when compared with CPP-ACP-F paste. CLINICAL SIGNIFICANCE: This study contributes to the understanding of the efficacy of CPP-ACP-F paste and 0.2% sodium fluoride mouthwash in the prevention of dental erosion.

Effect of layer thickness on the elution of monomers from two high viscosity bulk-fill composites: A high-performance liquid chromatography analysis.

AIM: The aim is to evaluate the effect of different layer thickness on the amount of elution of monomers from two high viscosity bulk-fill composites after 24 h and 1 month storage in ethanol using high-performance liquid chromatography (HPLC) analysis. MATERIALS AND METHODS: Forty-eight samples prepared from two high viscosity bulk-fill composite resins; Tetric EvoCeram Bulk Fill and x-tra fil were divided into three groups (n = 8) based on their layer thickness, i.e., Group 1 (2 mm), Group 2 (4 mm), and Group 3 (6 mm) and were then subdivided based on their storage period. The analysis of the eluates was performed using HPLC unit. Statistical analysis was performed using One-way ANOVA, independent sample t-test, and paired "t" test at a significance level of 0.05 (P < 0.05). RESULTS: Increase in layer thickness resulted in increased amount of bisphenol A-glycidyl methacrylate (Bis-GMA) and urethane dimethacrylate (UDMA) elution for both composites, i.e., Group 3 > Group 2 > Group 1 and there was statistically significant difference among all the groups. Tetric EvoCeram Bulk Fill showed a statistically significant increase in amount of Bis-GMA and UDMA elution for all groups compared to x-tra fil. Furthermore, increase in storage period resulted in statistically significant increase in amount of Bis-GMA and UDMA elution for both composites, i.e., Group 1B > Group 1A, Group 2B > Group 2A, and Group 3B > Group 3A. The mean value of UDMA elution was higher when compared to that of Bis-GMA elution for both composites and there was statistically significant difference for all groups. CONCLUSION: Within the limitations of this in vitro study, it was concluded that increase in layer thickness resulted in increased amount of Bis-GMA and UDMA elution for both Tetric EvoCeram Bulk Fill and x-tra fil.

Evaluation and comparison on the wettability of three root canal sealers after three different irrigant activation techniques: An in vitro study.

BACKGROUND: Wettability of root canal sealers to the root canal wall plays a significant role in the attainment of a fluid-tight seal. AIMS: This study aimed to evaluate and compare the wettability of three different root canal sealers on the root canal walls after three different irrigant activation techniques using the contact angle meter. SUBJECTS AND METHODS: Thirty-six single-rooted mandibular premolars after decoronation and cleaning and shaping up to size #35 were randomly divided into three groups with 12 samples in each group (n = 12) based on the different activation techniques: Group I (passive irrigation with side-vented needle), Group II (manual dynamic agitation), and Group III (passive ultrasonic irrigation). Root segments were split longitudinally and were subdivided into three subgroups based on the root canal sealers tested with four samples in each subgroup (n = 4): Subgroup A (Tubliseal EWT), Subgroup B (AH Plus), and Subgroup C (Endosequence BC sealer). A controlled volume droplet of sealer was placed on each specimen and was subjected to the contact angle meter. STATISTICAL ANALYSIS: Data were statistically analyzed using the one-way ANOVA and Tukey's post hoc test at a significance level of 0.05 (P < 0.05). RESULTS: A statistically significant difference was seen among all the groups and subgroups with the highest contact angle value for Group III and Subgroup C and the least value for Group I and Subgroup A. CONCLUSIONS: Passive irrigation with side-vented needle and Tubli-Seal EWT showed better wettability on dentin.

Comparative Evaluation of Antibiofilm Efficacy of Chitosan Nanoparticle- and Zinc Oxide Nanoparticle-Incorporated Calcium Hydroxide-Based Sealer: An In vitro Study.

AIM: This study evaluated the antibiofilm efficacy of calcium hydroxide-based sealer incorporated with chitosan nanoparticles (CS-NPs) and zinc oxide nanoparticles (ZnO-NPs) against two strains of Enterococcus faecalis (ATCC 29212, OG1RF). MATERIALS AND METHODS: The materials tested were Apexit Plus sealer in the commercial unmodified form and two modified forms with CS-NP and ZNO-NP, respectively. Crystal violet assay and confocal laser scanning microscopy (CLSM) study were used to assess the bacterial viability of biofilms grown in wells of microtiter plate and glass slides, respectively. Two E. faecalis strains (ATCC 29212, OG1RF) were used for the study. RESULTS: The crystal violet assay done on E. faecalis strain ATCC 29212 showed a significant decrease in the optical density (OD) value with ZNO-NP-incorporated calcium hydroxide sealer when compared with CS-NP. In the case of E. faecalis strain OG1RF, only ZNO-NP-incorporated calcium hydroxide-based sealer showed reduction in the OD value. In CLSM study done on E. faecalis strain ATCC 29212, only ZNO-NP-incorporated calcium hydroxide-based sealer showed reduction in the thickness of biofilm. No groups of OG1RF strain showed reduction in the thickness of biofilm. CONCLUSION: The incorporation of nanoparticles (ZnO and CS) into calcium hydroxide-based sealers significantly enhances the antibiofilm efficiency against E. faecalis strain ATCC 29212 but has questionable effectiveness against E. faecalis strain OG1RF. The present study demonstrates that ZNO-NP shows better antibiofilm efficacy than CS-NP against both strains of E. faecalis.

Classification of Imbalanced Data by Oversampling in Kernel Space of Support Vector Machines.

Historical data sets for fault stage diagnosis in industrial machines are often imbalanced and consist of multiple categories or classes. Learning discriminative models from such data sets is challenging due to the lack of representative data and the bias of traditional classifiers toward the majority class. Sampling methods like synthetic minority oversampling technique (SMOTE) have been traditionally used for such problems to artificially balance the data set before being trained by a classifier. This paper proposes a weighted kernel-based SMOTE (WK-SMOTE) that overcomes the limitation of SMOTE for nonlinear problems by oversampling in the feature space of support vector machine (SVM) classifier. The proposed oversampling algorithm along with a cost-sensitive SVM formulation is shown to improve performance when compared to other baseline methods on multiple benchmark imbalanced data sets. In addition, a hierarchical framework is developed for multiclass imbalanced problems that have a progressive class order. The proposed WK-SMOTE and hierarchical framework are validated on a real-world industrial fault detection problem to identify deterioration in insulation of high-voltage equipments.

Prevalence, Characteristics, and Complications of Supernumerary Teeth in Nonsyndromic Pediatric Population of South India: A Clinical and Radiographic Study.

INTRODUCTION: Supernumerary teeth are the presence of more number of teeth over the normal dental formula and may occur in permanent as well as early mixed dentition. This study determined the prevalence, characteristics, and complications caused by supernumerary teeth in nonsyndromic South Indian pediatric population. MATERIALS AND METHODS: Characteristics of supernumerary teeth determined by clinical and radiographic examination were recorded. The age, sex, number of supernumerary teeth, eruption status, morphology, position, orientation, and complications (if any) associated with supernumerary teeth were recorded for each patient who had supernumerary teeth. The data collected were statistically analyzed. RESULTS: Supernumerary teeth were detected in 45 subjects (1.1%), of which 34 (75.6%) were male and 11 (24.4%) were female. There was no association between the number of supernumerary teeth and the gender of the patient. The total number of supernumerary teeth among the affected 45 patients was 54. The average number of supernumerary teeth per person was 1.2. The number of supernumerary teeth was one in 35 cases, two in 8 cases, and 3 in 1 case. Of the 45 patients, 8 patients with supernumerary teeth were in deciduous dentition stage, 29 patients were in mixed dentition stage, and 8 patients were in permanent dentition stage. Most supernumerary teeth presented in the anterior maxilla. Morphologically, conical-shaped supernumerary teeth were the most common finding. 68.5% of supernumerary teeth presented with straight orientation and inverted orientation was seen in 24.1%. Complications seen in patients with supernumerary teeth were delayed or noneruption of adjacent tooth malposition or rotation of adjacent teeth, diastema formation, and formation of dentigerous cyst. CONCLUSIONS: Supernumerary teeth have an incidence of 1.1% in South Indian population and can cause many complications that can harm the developing occlusion. Knowledge about supernumerary teeth may help the dentist in early diagnosis and early intervention.

Incidence of Endodontic Flare-ups and Its Related Factors: A Retrospective Study.

AIMS AND OBJECTIVES: The aim and objective of the study were to determine the incidence of flare-ups during endodontic treatment and to identify the risk factors associated with flare-ups. SUBJECTS AND METHODS: A total of 1725 patients who were treated during the time period of 2009-2014 by the same endodontist were reviewed. Incidence of flare-up, patients' age, gender, status of pulp, tooth position, number of roots, and treatment provided were taken from their dental records. Relationship between these factors and flare-ups was examined. Statistical analysis was done using Pearson Chi-square test and Fisher's exact test. RESULTS: A total of 2% incidence of endodontic flare-ups was seen out of 1725 cases. Patient's age, gender, and diagnosis had a significant effect on the development of flare-ups (P < 0.05). Tooth type, position of tooth, number of root canals, number of visits, and treatment modality had no significant effect on flare-up incidence. CONCLUSIONS: Diagnosis plays an important role in predicting the incidence of flare-ups. Patients in the age group of 40-60 years had a higher risk of developing flare-ups. Women compared to men are more prone to flare-ups.

Complete Overlay Denture for Pedodontic Patient with Severe Dentinogenesis Imperfecta.

Dentinogenesis imperfecta (DI) is a hereditary condition that may affect both primary and permanent dentition and is characterized by abnormal dentin formation. The teeth may be discolored with chipping of enamel and, in untreated cases, the entire dentition may wear off to the gingiva. This may lead to the formation of abscesses, tooth mobility, and early loss of teeth. In the Indian population, DI is found to have an incidence of 0.09%. Treatment of DI should aim to remove infection, if any, from the oral cavity; restore form, function, and esthetics; and protect posterior teeth from wear for maintaining the occlusal vertical dimension. Treatment strategies should be selected based on the presenting complaint of the patient, patient's age, and severity of the problem. This case report presents the management of severe DI with tooth worn off until gingival level in a very young patient using complete overlay denture, which has not been reported earlier. How to cite this article: Syriac G, Joseph E, Rupesh S, Mathew J. Complete Overlay Denture for Pedodontic Patient with Severe Dentinogenesis Imperfecta. Int J Clin Pediatr Dent 2017;10(4):394-398.

Root canal treatment of a maxillary first premolar with three roots.

Successful root canal treatment needs a thorough knowledge of both internal and external anatomy of a tooth. Variations in root canal anatomy constitute an impressive challenge to the successful completion of endodontic treatment. Undetected extra roots and canals are a major reason for failed root canal treatment. Three separate roots in a maxillary first premolar have a very low incidence of 0.5-6%. Three rooted premolars are anatomically similar to molars and are sometimes called "small molars or radiculous molars." This article explains the diagnosis and endodontic management of a three rooted maxillary premolar with separate canals in each root highlighting that statistics may indicate a low incidence of abnormal variations in root canal morphology of a tooth, but aberrant anatomy is a possibility in any tooth. Hence, modern diagnostics like cone beam computed tomography, and endodontic operating microscope may have to be used more for predictable endodontic treatment.