Faculty Bibliography

AIM/OBJECTIVE:Periapical mucositis (PAM) is defined as inflammation of the periapical tissues and localized oedema of the maxillary sinus mucosa, typically resulting from periradicular disease. Radiographically on cone-beam computed tomography (CBCT), PAM presents as mucosal thickening or a dome-shaped soft tissue expansion along the floor of the maxillary sinus, adjacent to the affected root apex. Although several studies have evaluated PAM, their findings vary considerably. This study aims (1) to evaluate the prevalence of PAM in maxillary posterior teeth amongst patients at NYU College of Dentistry, Department of Endodontics, and (2) to identify predisposing factors associated with PAM. METHODOLOGY/METHODS:CBCT evaluation and chart review were conducted at NYU College of Dentistry from 2016 to 2021. A total of 586 scans were screened, and 335 scans were included. The presence of PAM, periapical osteoperiostitis, maxillary sinus floor bony erosion, age, sex, pulpal and periapical diagnosis, size of the lesion, the vertical and horizontal distance between the sinus floor and roots, number of roots with apical lesions, type of tooth and iatrogenic errors during treatment were recorded. Chi-square, Fisher's exact tests and logistic regression were used to analyse the data. RESULTS:Of the 335 scans included, 13 presented with mucositis without periradicular disease and were excluded from the analysis. A total of 322 scans were analysed. The prevalence of PAM was 55.5%. The presence of maxillary sinus floor bone erosion was associated with 7.56 times higher odds of PAM than those without sinus floor erosion (p < 0.001). Each incremental increase in CBCTPAI was associated with a 1.43-fold increase in the odds of PAM occurrence (p = 0.004). CONCLUSION/CONCLUSIONS:PAM was present in over half of patients presenting with apical periodontitis affecting the posterior maxillary dentition. Maxillary sinus bony floor erosion and periapical lesion size were predisposing factors to PAM development.

INTRODUCTION/BACKGROUND:The purpose of this study was to evaluate long-term outcomes of nonsurgical retreatment (NS-ReTx) procedures performed by a single endodontist in private practice. METHODS:This retrospective cohort study evaluated NS-ReTx procedures performed between the years 1986 and 2019, meeting the following inclusion criteria: minimum of 1-year follow-up and preoperative, postoperative, and follow-up radiographs available for analysis. Procedures were evaluated clinically and radiographically, and treatment outcomes were reported. A subset of cases included cone-beam computed tomography (CBCT) images and CBCT-assessed periapical healing was reported for these cases. The effect of clinical factors on radiographic healing was assessed using a Cox proportional hazard regression model. The Kaplan-Meier method estimated the probability of tooth survival at each year of follow-up. RESULTS:A total of 241 NS-ReTx procedures from 202 patients met the inclusion criteria. The median patient age at time of NS-ReTx was 54 years. Molars were the most frequently treated tooth type, 57.68%. Radiographic healing at the median follow-up time, 9.14 years (n = 231) was 64.07% healed (148 of 231), 7.36% healing (17 of 231), and 28.57% unhealed (66 of 231). An additional 10 teeth were extracted before any radiographic follow-up. CBCT-assessed periapical healing ("strict" criteria) was 65.63% over a median follow-up time of 9.18 years. Tooth survival following NS-ReTx was 93.3% at 5 years and 85.3% at 10 years. CONCLUSIONS:The study demonstrates that radiographic periapical healing and treatment success improve over time and that tooth survival following NS-ReTx is favorable long-term.

This study evaluated changes in the number of cycles to fracture (NCF) of Nickel-Titanium (NiTi) files after repeated use in simulated canals and investigated the potential relationship with stress-induced martensite (SIM) transformation effect. A total of 225 ProTaper Ultimate (PTUL) files were divided into three groups: Group 1 consisted of new files, Group 2 comprised files used to shape two resin simulated canals, and Group 3 consisted of files used to shape four canals. The simulated resin canals with a 16 mm length of J-shaped with 35° curvature were prepared using PTUL Slider, Shaper, F1, F2, and F3 files sequentially. After instrumentation, the cyclic fatigue resistance of each sequential file was assessed in a 35° curved steel canal by rotating at 400 rpm using a custom-made device. Statistical analysis was performed using one-way ANOVA with Tukey's post hoc test or Kruskal-Wallis with Dunn's test with Bonferroni correction for parametric and non-parametric data, respectively. Slider and Shaper maintained stable NCF across all groups (p > 0.05). In contrast, F1 showed a transient increase (117.7%) after two uses but declined significantly (91.6%) after four uses (p < 0.05). F2 and F3 demonstrated progressive NCF reductions (F2: 72.9%; F3: 71.5% after four uses), with F3 showing the most pronounced decline (p < 0.05). Repeated use of NiTi files reduced their cyclic fatigue resistance in a file-specific manner, with larger finishing files most affected. The distinctive F1 pattern suggests potential preload-related or SIM transformation effects that warrant further metallurgical investigation.

INTRODUCTION/BACKGROUND:There is a lack of epidemiology studies on cemental tears. This study aimed to (i) investigate the prevalence of cemental tears among the patients referred to a Postgraduate Endodontic Clinic, (ii) classify the cases diagnosed with cemental tears, and (iii) assess factors associated with cemental tears. MATERIALS AND METHODS/METHODS:This retrospective, cross-sectional study included 445 cases/teeth recruited between 1 September 2019 and 31 March 2024 at a University Postgraduate Endodontic Clinic. Information was collated from the clinical records of case history, clinical findings and radiographic interpretations from periapical radiograph (PR) and cone beam computed tomography (CBCT) images. For each case/tooth, cemental tear/s were categorised as either absent or present, and those with cemental tear/s were further classified. Thirty potential factors were studied, including patient-, jaw-, tooth-, previous endodontic treatment and periodontal-related factors. Factors were individually tested using univariate analysis with Pearson chi-squared (exact) tests. Any significant factors identified were further subjected to multiple logistic regression analyses based on a forward stepwise regression model (p < 0.05). RESULTS:Cemental tear/s were found in 25 out of 445 cases/teeth, with a prevalence of 5.6%. Sensitivity and specificity of PR in detecting cemental tears were 0.6 and 1.0, respectively. Most cases/teeth detected were classified as Class 2 and 4 (n = 19, 76%) or Stage C and D (n = 19, 76%). Mean age of the subjects with cemental tears was 58.7 years, with comparable prevalence between males and females. Most cases (72%) with cemental tear/s had root canal treatment initiated or completed. Incisors, increased tooth mobility, severe crestal bone loss and adequate root filling quality were significantly associated with the higher prevalence of cemental tears (p < 0.05). CONCLUSION/CONCLUSIONS:Cemental tears should always be considered as a differential diagnosis in endodontic practice. Clinicians should be particularly vigilant for increased risks of cemental tears in incisors, mobile teeth, teeth exhibiting increased crestal bone loss and those with adequately filled root canals, as they may be misdiagnosed as periodontal-endodontic lesions. The use of CBCT is crucial for accurate diagnosis, guiding effective treatment planning and improving clinical outcomes in endodontic management.

BACKGROUND:Evidence suggests that pediatric patients requiring endodontic treatment in the permanent dentition are often a "missed population". AIM/OBJECTIVE:This study surveyed pediatric dentists and endodontists about the frequency with which they encounter pediatric patients requiring endodontic treatment, their training, practice patterns, and decision-making considerations for the treatment of immature permanent teeth. DESIGN/METHODS:analysis. The level of significance was set at 0.05. RESULTS:The response rate was 13.1% (n = 840). The frequency of clinicians encountering pediatric patients requiring endodontic treatment for permanent teeth did not differ significantly by specialty. Pediatric dentists and endodontists reported statistically significant differences in their practice patterns related to the performance of vital pulp therapy (p < 0.001) and procedures for necrotic immature permanent teeth (p < 0.001). Among specialists, apexification was more frequently performed than regenerative endodontic procedures (REPs) (p < 0.001). When asked to consider clinical and patient factors related to the treatment of necrotic immature permanent teeth, pediatric dentists most frequently responded that they were "unsure" of their preferred treatment. CONCLUSION/CONCLUSIONS:Standardized clinical knowledge and management of immature permanent teeth between specialties may improve interdisciplinary care for pediatric patients.

INTRODUCTION/BACKGROUND:This study aimed to evaluate the correlation between the fibrous area ratio and the number of cycles to failure (NCF) in terms of fatigue fracture resistance of NiTi rotary files. METHODS:ProTaper Universal (PTU) and ProTaper Gold (PTG) files of size F2 (25 mm) were tested to make cyclic fatigue fracture using a custom-made device simulating a 35° canal curvature (n = 24). Using the fractured fragments, scanning electron microscopy (SEM) was taken to analyze the fracture surfaces, focusing on fibrous areas on the cross-sections. Fibrous area ratios were calculated using ImageJ software, and NCF was determined by multiplying the time to fracture by rotational speed. Statistical analysis was performed to evaluate differences between groups and assess the correlation between fibrous area ratio and NCF (P < .05). RESULTS:SEM analysis revealed a higher fibrous area ratio in PTU files (P < .05). The correlation analysis indicated a weak relationship between fibrous area ratio and NCF in both groups. PTG files demonstrated significantly higher NCF compared to PTU files (P < .05). PTG group had a significantly lower fibrous area ratio than the PTU group (P < .05). CONCLUSION/CONCLUSIONS:While PTG files show improved cyclic fatigue resistance due to thermal processing, the fibrous area ratio is not a strong representing factor or predictor of NCF. Heat treatment influences the property of fracture resistance more significantly than propagation process of cyclic fatigue fracture.

INTRODUCTION/BACKGROUND:from an endodontic model that duplicated a root canal configuration of a human natural tooth. METHODS:. Data were analyzed using two-way analysis of variance test (α = .05). RESULTS:than the conventional group regardless of the type of needle (P < .05). However, no significant difference was found among the needles in the PUI group. CONCLUSIONS:regardless of the type of irrigation needle.

BACKGROUND:Historical reports of unpredictable outcomes associated with vital pulpal therapies, particularly direct pulp capping (DPC), have contributed to clinicians' skepticism of the procedure. Contemporary reports highlight more predictable outcomes of vital pulpal therapies, inclusive of DPC. There is a dearth of reported patient-centered outcomes of these procedures. METHODS:Insurance claims were used in an observational, retrospective cohort study to evaluate outcomes of DPC performed on permanent teeth. Statistical analyses included Kaplan-Meier survival estimates and Cox proportional hazards regression. Log-rank tests were used to evaluate unadjusted differences in survival. Cox proportional hazard regression was used to evaluate the adjusted hazard of adverse event occurrence. RESULTS:The analytic cohort included 4,136 teeth from 3,716 patients. DPC procedures were identified in public-payer (85.5%) and private-payer (13.4%) insurance claims databases. After DPC, procedure survival rate was 83% and tooth survival rate was 93% during a mean follow-up time of 52 months. Molar tooth type, same-day permanent restoration placement, and amalgam restoration type were significant positive predictors of procedure (DPC) survival. Age was not a statistically significant predictor of procedure survival after controlling for tooth type, gender, time to restoration, and restoration type. Nonmolar tooth type and younger age were significant positive predictors of tooth survival after DPC. Failures were most likely to occur within the first year. CONCLUSIONS:DPC has favorable patient-centered outcomes and contributes to long-term tooth survival. PRACTICAL IMPLICATIONS/CONCLUSIONS:The favorable patient-centered outcomes of DPC bolster calls to consider cost-effectiveness and access to care for endodontic procedures.

INTRODUCTION/BACKGROUND:The objective of this study was to report the long-term outcome of autotransplantation of premolars to other premolar recipient sites. METHODS:The sample was limited to adolescents seeking orthodontic treatment, and all had 1 or 2 premolars transplanted to a recipient site in which a premolar was congenitally missing. The transplantations were performed between 1980 and 2008, comprising 29 premolars in 22 males and 28 premolars in 22 females. Systematic clinical and radiographic follow-up varied from 1 year to 36.8 years, with a mean observation time of 18.9 years and a median of 19.2 years. Of the 57 transplanted teeth, 52 were subjected to orthodontic forces. RESULTS:A total of 9 of 57 teeth (15.8%) were lost during the observation period, and 8 of 9 lost teeth had been functional for at least 9 years posttransplantation. Of the 48 surviving transplants, 6 did not meet the criteria for success, giving an overall success rate of 73.7%. Complications were diagnosed within 5 years from the transplantation in 4 of 57 teeth (7.0%) and later in 11 of 57 (19.3%). The Kaplan-Meier survival curve shows that the complication-free proportion of transplants decreased at a constant rate over the observation time. The average survival time, taking censoring into account during follow-up of 36.8 years, was estimated as 28.5 years. The complications in the 15 teeth were classified into 4 categories: periapical lesions (6 teeth), inflammatory resorption (5 teeth), abrupt fracture (2 teeth), and ankylosis (2 teeth). CONCLUSIONS:Overall, premolar transplants in all stages of root formation have high success and survival rates. Transplants with complications may survive temporarily and preserve critical arch space and alveolar bone. Transplants with normal healing may have latent weaknesses that can eventually affect long-term survival.

INTRODUCTION/BACKGROUND:The purpose of this study was to evaluate the effect of side flattening of cutting flutes on the cyclic resistance and torsional resistance of nickel-titanium files. METHODS:Both novel flattened Platinum V.EU (PL) and standard nonflattened CC Premium V.EU (CC) rotaries were tested. For cyclic fatigue tests, all the files were rotated in an artificial root canal with a curvature of 45° and a radius of 6.06 mm at 300 rpm (n = 15 in each group). The number of cycles to failure (NCF) was calculated. For torsional tests, the files were rotated at 2 rpm clockwise until fracture occurred. The maximum torque value at fracture was measured and the toughness and distortion angle were computed. Subsequently, 5 fragments were randomly selected in each experiment, the cross-section and longitudinal direction of the fragments were photographed using a scanning electron microscope. An unpaired t-test was performed at a significance level of 95%. RESULTS:There was a statistically significant difference in NCF between CC and PL (P < .05). CC showed higher NCF than PL. There was no statistically significant difference between CC and PL with regards to the parameters related to torsional resistance (distortion angle, ultimate strength, and toughness) (P > .05). CONCLUSION/CONCLUSIONS:Within the limitations of this study, side flattening of the file did not improve cyclic resistance or torsional resistance of the files. As side flattening may reduce a file's cyclic resistance, such files should be used with caution in clinical practice.