A survey was conducted to assess the current state of predoctoral endodontic education in the United States. Fifty-one schools received surveys and 73% responded. Seventy-six percent were from public schools with most having a graduate endodontic program (84%). Preclinical training most often began in the spring of second year and clinical training started in the fall of third year (each 54%). All programs that responded stated that endodontists routinely instruct students in the clinic. Sodium hypochlorite 2.5% was the irrigation of choice. Calcium hydroxide was the most common intracanal medicament. Cold lateral condensation with gutta-percha was the most frequently indicated obturation technique. Sixty-two percent of programs had microscopes, with 1-2 cases treated with microscope per week. Findings suggest that endodontists are still an integral part of teaching predoctoral dental students in the United States.

Cracked teeth may be difficult to diagnose. Craze lines rarely become symptomatic or require treatment. Cracks in the enamel and dentin alone may or may not become symptomatic and require restorative treatment. However, cracks extending into the enamel, dentin, and pulp chamber provide an avenue for bacteria to establish infection and this commonly results in symptoms and the need for endodontic and restorative treatment. The published endodontic literature has limited information regarding the prevalence or predictive factors for cracks extending into the pulp chamber of teeth. The purpose of this study was to determine the prevalence and classification of intrapulpal cracks in maxillary premolars and to identify factors that may aid in diagnosing the existence and extent of a crack. The cracks were classified according to the Intrapulpal Crack Classification System proposed by Detar in 2014. All maxillary premolar teeth treatment planned for non-surgical root canal therapy (NSRCT) or retreatment (RETX) at Virginia Commonwealth University (VCU) Graduate Endodontic Practice from January 2014 through February 2015 were included in the study after obtaining patient consent. Teeth were examined visually, stained, and examined microscopically for the presence of an intrapulpal crack. Demographic information, subjective data associated with the chief complaint, objective results of diagnostic testing (percussion, palpation, bite stick test, transillumination, probing depths), existing restorations, pulpal diagnosis, and periapical diagnosis were analyzed using chi-square and multiple logistic regression (P

The aim of this study was to compare the incidence of root canal dentinal micro-cracks after canal instrumentation using reciprocating files (WaveOne Gold® and Twisted Adaptive®) and continuous rotation files (Edge Evolve® and EndoSequence®) in an ex-vivo benchtop study. This project used a novel methodology of finding dentinal defects using the “K-cube”, which allows evaluators to visualize sectioned root surfaces before instrumentation and after instrumentation. Mesial roots from 40 human mandibular first molars were divided into 4 groups of 10 for each file type. Root section pictures were taken with a Zeiss Discovery V20 stereomicroscope before and after canal instrumentation. Each of the pre-instrumentation and post-instrumentation images were evaluated for dentinal defects by four calibrated endodontists utilizing REDCap survey. Using a chi-square analysis, there was no statistically significant difference between dentinal defects created by continuous and reciprocating rotation (p=0.1924) and no difference between the four file types (p=0.2317).

Introduction: The aim of this in vitro study was two part. The first being to assess and compare the amount of dentin removed by an instrument with a taper of 0.04 versus an instrument with a taper of 0.06 using the Edge Evolve® file system at different increments within the canal system. Secondly, this study evaluated whether instrumentation with either taper resulted in a remaining dentin thickness (RDT) of less than 0.3mm. If this RDT was imposed upon, fracture resistance was compromised. Both pre and post instrumentation measurements were taken of samples instrumented with the 0.04 and 0.06 tapered files. Methods: Ten maxillary premolars exhibiting Weine class III canal systems and minimal to no root canal curvature were mounted in an acrylic resin filled K-cube. Each acrylic resin cube was sectioned horizontally at 3, 6, 9, and 12mm increments from the apex. The K-cube is a device which allows the investigator to disassemble and then reassemble root slices in their original orientation. Dentin thickness was measured at three positions on each canal using the Zeiss Discovery V20 stereomicroscope. The sections were then reassembled into the K-cube. The ten premolar roots were separated into two groups. In half of the teeth the buccal canals were instrumented with 0.04 tapered files and the lingual canals instrumented with 0.06 tapered files. In the other half of the teeth, instrumentation was reversed: the buccal canals were instrumented with 0.06 tapered files and the lingual canals were instrumented with 0.04 tapered files. Root sections were again separated, and the remaining dentin thickness was measured. A repeated-measures mixed-model ANCOVA was performed to analyze the effect of taper on RDT. Results: The amount of dentin removed was statistically different between the two tapers (P=0.02). Across all of the slices and positions, the 0.04 tapered instruments had an average pre-post difference of 0.1313mm. The 0.06 tapered instruments had an average pre-post difference of 0.1672mm. None of the instruments imposed upon the recommended 0.3mm RDT. Conclusion: The 0.04 tapered files instrument with greater conservancy than the 0.06 tapered files. The 0.06 tapered files had their greatest effect on the canal in the 9mm and 12mm sections. However, neither taper imposed upon the recommended RDT for optimal fracture resistance within the apical 12mm root portion observed in this study. Keywords: Instrumentation, Edge Evolve, Root canal preparation, Taper

Purpose: The aim of this study was to assess the outcome of treatment of teeth with open apices managed by the orthograde placement of a bioceramic apical barrier as well as to identify potential outcome factors for this type of treatment. Methods: Patient records were pooled from graduate resident cases completed at Virginia Commonwealth University between January 1, 2010 and May 31, 2018. A total of 515 patients were identified using relevant ADA codes and a key word search within the patient record database. A total of 104 patients (119 teeth) had an open apex that had NSRCT utilizing a bioceramic apical barrier, with 32 of the patients (36 teeth) returning for follow-up. Results: Of the 36 examined teeth (30.8% recall rate),72% were considered healed. 92% were considered healed or healing. No predictive variable analyzed had a significant effect on the outcome. Conclusion: Overall, these results indicate that a bioceramic apical barrier technique is a promising treatment option for obturating teeth with open apices during NSRCT.

Purpose: This study aimed to survey current 3rd and 4th year dental students, academic deans, and department chairs within U.S. dental schools to analyze the level of understanding; education; guidelines; and overall awareness regarding antibiotic use within dentistry and antimicrobial resistance. Methods: A 25-question survey intended for 3rd and 4th year dental students and a 20-question survey intended for academic deans and various department chairs of U.S dental schools were each developed utilizing REDCap. The survey invitations were sent via e-mail to the current academic dean of each U.S. dental school for distribution. Results: There were a total of 18 respondents from the academic dean and department chair survey and 172 student respondents. Overall, 71% of students reported that they could benefit from more education regarding antibiotics. The majority of both groups agreed that dentistry should play an important role in reducing antimicrobial resistance, but most dental students were ‘not at all familiar’ with the term antimicrobial stewardship and several were unsure if clinical guidelines were present at their schools. Conclusion: Improvements to the dental educational curriculum regarding the responsible use of antibiotics, along with the implementation of stewardship programs within dentistry are strongly encouraged.

Purpose: Determine the timeframe of bacterial penetration that occurs to the apex when obturation material (gutta percha) is exposed to bacteria for a set period of time (45 days) and to determine if bacterial penetration of the obturated root is influenced by the type of irrigant used during the final rinse (17% EDTA vs 2% Chlorhexidine vs full strength 5.25% NaOCl). Methods: Thirty-six extracted teeth, including six controls, were instrumented and irrigated with 5.25% NaOCl followed by a final rinse of either: 17% EDTA, 2% Chlorhexidine, or 5.25% NaOCl, and then obturated. Each root was suspended between two chambers: the coronal chamber inoculated with brain heart infusion broth and 〖10〗^8 colony-forming units of Enterococcus faecalis, the apical chamber with brain heart infusion broth. The latter was checked daily for turbidity, indicating bacterial leakage. Results: After excluding teeth with clear indications of experimental failure, 21 teeth were included in the analysis. Leakage rates were not significantly difference across the three groups (Chlorhexidine: 14%, EDTA: 67%, NaOCl: 50%; p-value=0.1581). Time to leakage was not significantly difference across the three groups (p-value=0.2470). Conclusion: Within the limitations of this study it was shown that leakage occurs between 4-42 days and that there was no significant difference between the different solutions in preventing leakage.

Introduction: Socioeconomically disadvantaged children have limited access to orthodontic services not only because of their families’ competing needs for limited resources, but also because of the limited availability of orthodontists in their communities and a shortage of orthodontists who are willing to treat patients enrolled in Medicaid. We will systematically explore the hypothesis that an early interceptive treatment protocol using removable appliances provides the same treatment outcome but better cost-effectiveness than a traditional fixed-appliance protocol. Methods: Interim data on a prospective study with patients being treated either in private practice with rational fixed Phase I orthodontic treatment (n=11) or in a community clinic with removable interceptive orthodontic treatment (n=10). Initial and post treatment study models were acquired along with pretreatment PAR and clinical photos. PAR and ICON scores were assessed on all initial and final casts. Cost effective analyses were performed comparing the two treatment groups as well as comparing the removable group to no treatment. Sensitivity analyses were performed to assess the robustness of our data while manipulating certain treatment outcome variables. Results: For the fixed group the average PAR score at T2 was 7.6 with a 68% reduction from T1 to T2, while the ICON average score was 16.2 with a 67% reduction. In the removable group the average PAR score at T2 was 13.4 with a lesser reduction from T1 to T2 than the fixed group at 48% (p=0.20), while the ICON average score was 25.3 with a significantly lower reduction of 39% when compare to the fixed group (p=0.037). Cost effectiveness analyses showed that the removable appliance treatment protocol was cost effective when compared to no treatment but not cost effective when compared to 3 the traditional fixed Phase I treatment using the studies measured probabilities of success. Conclusion: The removable appliance protocol used at the Fruitvale community clinic can effectively reduce the severity of malocclusions. However, in order for this treatment to be cost effective when compared to a traditional fixed Phase I protocol it needs to demonstrate consistent clinical results and minimize the probability of “No Improvement”.

ABSTRACT Introduction: Medical imaging continues to play an increasing role in health care and is an integral part of medicine and dentistry. Recent technological advancements have led to the development of fully automated landmark identification (ALI) systems capable of tracing Cone-Beam Computed Tomography (CBCT). The purpose of this study was to evaluate the accuracy and reliability of an ALI system as a tool for automatic landmark location compared to human judges. Methods: One hundred subjects’ CBCT volumes from multiple imaging centers were traced by two human judges who were calibrated and had an ICC close to 1. Fifty-three landmarks were identified in the x, y, and z coordinate planes using Checkpoint Software (Stratovan Corporation, Davis, CA). The ground truth was created by calculating the mean values of the x, y, and z coordinates for each landmark across both judges’ landmark identification. To evaluate the accuracy of ALI, the mean absolute error at each coordinate and mean error distance (mm) between the human landmark identification (ground truth) and the ALI were determined, and a successful detection rate (SDR) was calculated. Results: Overall, the ALI system was as successful at landmarking as the human judges with the exception of a few landmarks. The mean error distance for all 53 landmarks was 4.04 mm ± 6.5. Forty-nine out of 53 landmarks were located within a mean error of 4mm when the average for the coordinates of human judges was considered as a ground truth. Conclusion: Across all three coordinate planes, 96% of the landmarks had a mean absolute error of less than 4mm when compared to the ground truth. The ALI was more precise than humans when identifying landmarks on the same image at different times. This study demonstrates the promise of ALI in aiding orthodontists with landmark identification on CBCTs in the future.

The objective of this study was to evaluate the biofilm removal efficacy of three root canal treatment systems: ProUltra® PiezoFlow™, traditional needle irrigation, and the GentleWave® system in an ex-vivo benchtop study. Twenty-four extracted maxillary and mandibular molars were selected. Teeth were all instrumented to a master apical file size #25 with 4% taper. Teeth were then randomly divided into four experimental groups and two control groups. The root canals were inoculated with a culture of Enterococcus faecalis and incubated for five weeks to form a biofilm. Each group was then treated with one of the different root canal treatment systems using 6% sodium hypochlorite (NaOCl) as per the respective manufacturer’s recommendation followed by a rinse with water. Following treatment, teeth were decoronated and roots were sectioned longitudinally. Three scanning electron microscope images were taken at the apical level per root half at 5000x magnification. Images were scored by four calibrated examiners blind to group membership using a four-point scoring system (<5% coverage, 5-33%, 34-66%, and >66%). Results were analyzed using mixed model ANOVA. All the experimental groups were significantly better than the positive control group in removing biofilm. Among the experimental groups, the GentleWave® 15/04 group was significantly better than the other groups. There was no significant difference between the GentleWave® and the ProUltra® PiezoFlow™. Traditional needle irrigation scored the worst in reducing E. faecalis biofilm. The GentleWave™ system was as effective at intracanal biofilm removal as the ProUltra® PiezoFlow™ and better than traditional needle irrigation using 6% NaOCl as an irrigant.