Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An ex vivo study.

AIM: To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems. METHODOLOGY: Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used. RESULTS: Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05). CONCLUSION: The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.

The Outcomes of Endodontically Treated Teeth Restored with Custom-Made Cast Post-and-Core Restorations: A Retrospective Cohort Study.

INTRODUCTION: Custom-made cast post-and-core (CMCPC) restorations have long been used to restore structurally deficient endodontically treated teeth (ETT). However, the evidence regarding their impact on the outcomes of ETT is largely inconclusive. This study evaluated the long-term treatment outcome of ETT restored with CMCPC. METHODS: This retrospective cohort study examined the dental records of patients that received CMCPC at a specialty private practice in Toronto, Canada between 1999 and 2021. The proportion of ETT with complete periapical healing and those that survived were estimated, and prognostic factors were investigated using multiple logistic and Cox regression analyses respectively (P < .05). RESULTS: A total of 500 and 1000 teeth met periapical healing and survival criteria, respectively. The periapical healing rate was 88.8% and was associated with the presence of baseline periapical radiolucency [odds ratio = 0.1; 95% confidence interval (CI), 0.05-0.2; P < .001]. The survival after a median follow-up time of 52.9 months (interquartile range: 26.5-99.4) was 90.1% and was associated with <75% of root length in bone [hazard ratio (HR) = 2.6; 95% CI, 1.0-6.6; P = .033], type and quality of final restoration (HR = 2.09; 95% CI, 1.1-3.9; P = .020; HR = 2.3; 95% CI, 1.2-4.5; P = .008, respectively), and the presence of periapical radiolucency at the latest recall (HR = 3.2; 95% CI, 1.7-6.3; P < .001). CONCLUSIONS: The outcome of ETT restored with CMCPC was favorable. CMCPC may be regarded as a viable restorative option for structurally deficient ETT.

A Scoping Review of Four Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies: Part 3-A Proposed Framework for Standardized Data Collection and Reporting of Endodontic Outcome Studies.

INTRODUCTION: Despite initiatives to standardize and improve reporting of rapidly growing endodontic outcome research studies, issues related to missing and ambiguous information are still of great concern. In this article, we propose a framework for standardized data collection and a compiled checklist for reporting of various study designs on endodontic outcome. METHODS: A comprehensive search was carried out to locate randomized controlled trials, cohorts, case-control studies, or case series of >100 patients that reported on endodontic outcomes. We reviewed these articles to develop a Data Collection Template and compiled a checklist for reporting of future endodontic outcome research. RESULTS: Out of 354 eligible articles previously reported in our scoping review on endodontic outcome studies, 109 articles were selected and screened for study variables or levels of categorization. Our complied Data Collection Template was developed in 19 domains to highlight important demographic, preoperative, intraoperative, and postoperative variables. Because of the specific needs for endodontic outcome literature, we also proposed a compiled checklist (consisting of 4 main domains) to facilitate the reporting of various study designs on endodontic outcome studies. This checklist included simple descriptions of the required items and examples on reporting from published endodontic studies. CONCLUSIONS: By facilitating the collection and reporting of relevant research data by investigators in private practice and academia, we hope that the proposed Data Collection Template and reporting guideline can highlight the importance of standardization among clinicians and researchers while producing valid scientific information that will support evidence-based treatment decisions.

A Scoping Review of 4 Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies-Part 2: Outcome Measures.

INTRODUCTION: Inconsistencies in the definitions of endodontic outcome terminology jeopardize evaluations of proposed interventions and patient care quality. This scoping review aimed to provide groundwork to develop a set of basic outcomes in endodontics. METHODS: We performed a comprehensive literature search for randomized controlled trials, cohort studies, case-control studies, and case series (≥10 patients) published after 1980 with patients ≥10 years of age with any preoperative pulpal and periapical diagnosis in permanent teeth requiring nonsurgical root canal treatment, retreatment, or apexification. Abstracted data on outcome assessment methods, assessors, and domains were reported after univariate and bivariate analyses. RESULTS: Treatment outcomes were evaluated radiographically (88%) or clinically (73%). Although 2-dimensional radiography exceeded 3-dimensional radiography, the use of the latter has increased since 2010, mostly for nonsurgical retreatments. Of 19 identified outcomes, 5 were most frequent: success (168 studies, 40%), radiographic healing (128 studies, 30%), survival (of an asymptomatic tooth [48 studies, 12%] or of a procedure code in administrative databases [31 studies, 7%]), pain assessment (14 studies, 3%), and quality of life (11 studies, 3%). Clinician-centered outcomes have been most frequently studied since the 1980s (71%), in academic settings (76%), and using a prospective design (45%). Patient-centered outcomes were reported in 19% of studies before 2010 and 30% since 2010. They were more common among retrospective studies (49%). CONCLUSIONS: Patient-centered outcome measures are lacking in endodontic studies. The state of available research can provide a baseline for the development of a core outcome set in endodontics, which should represent the important patient-centered outcomes in conjunction with well-validated clinician-centered outcomes.

A Scoping Review of 4 Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies-Part 1: Process and General Results.

INTRODUCTION: Despite initiatives to standardize reports, variances in study design, outcomes assessed, and tools used are persistent in the literature. This review scoped the existing literature on endodontic outcome studies for future development of core outcome sets. METHODS: A comprehensive literature search of randomized controlled trials, cohort studies, case-control studies, and case series (≥10 patients) published after 1980 including patients ≥10 years of age with any preoperative pulpal and periapical diagnosis in permanent teeth requiring nonsurgical root canal treatment (NS-RCT), retreatment (NS-ReTx), or apexification was performed. Abstracted data were reported through descriptive statistics. RESULTS: Of the 9957 studies screened, 354 were included. An increase in the quantity of endodontic outcome publications and levels of evidence in their study design was noted over the past 4 decades. Although 41% of the studies included participants 26-50 years of age, literature including participants >50 years old has increased since 2000. Apexification and NS-ReTx were mostly provided by specialists and postgraduate students. The most common follow-up period was 2-5 years (35%), and most randomized controlled trials (58%) reported follow-up times <1 year. Multiple-visit treatment was most common in apexification studies (85%). Deficiency, inconsistency, and ambiguity were observed across many reports. CONCLUSIONS: NS-ReTx and NS-RCT/NS-ReTx studies have increased over the past 2 decades, particularly those focusing on molars and patients >50 years old. Despite the progress in endodontic research, heterogeneity in reporting styles yields considerable limitations, particularly data standardization challenges and inconsistencies in methods and results reporting. This scoping review highlighted the state of available research and supported the development of standardized guidelines for future investigations.

Efficacy of 3 Supplementary Irrigation Protocols in the Removal of Hard Tissue Debris from the Mesial Root Canal System of Mandibular Molars.

INTRODUCTION: Instrumentation of the mesial root canal system of mandibular molars may hinder disinfection by packing hard tissue debris within the isthmuses. The removal of accumulated hard tissue debris (AHTD) by 3 supplemental irrigation systems, 2 ultrasonically activated and 1 multisonic, was assessed with micro-computed tomographic imaging. METHODS: Twenty-four extracted mandibular molars with 2 mesial canals connected by an isthmus and converging to a single foramen were selected. After preparation of the mesial canals with WaveOne Gold instruments (Dentsply Maillefer, Ballaigues, Switzerland), anatomically matched specimens were assigned to 3 final irrigation protocols (n = 8): intermittent ultrasonic (IU) with an ultrasonically energized 200-µm wire (Irrisafe; Satelec, Bordeaux, France), continuous ultrasonic (CU) with an ultrasonic irrigation needle (ProUltra PiezoFlow, Dentsply Maillefer), and GentleWave (GW) system (Sonendo Inc, Laguna Hills, CA). Specimens were scanned (SkyScan 1176; Bruker-microCT, Kontich, Belgium) at 17.18-µm pixel size before and after preparation and irrigation protocols. Data sets were coregistered, and the percentage reduction of AHTD calculated within the canals and isthmus for each specimen was statistically compared using 1-way analysis of variance and post hoc Tukey tests with a 5% significance level. RESULTS: The mean percentage reduction of AHTD in canals and isthmuses was significantly higher for GW (96.4% and 97.9%, respectively) than for CU (80.0% and 88.9%, respectively) (P < .05). AHTD reduction for IU (91.2% and 93.5%, respectively) did not differ significantly from GW and CU (P > .05). CONCLUSIONS: GW achieved greater efficacy in the removal of AHTD from the mesial root canal system of mandibular molars compared with CU but not IU. The efficacy of CU and IU was comparable.

Assessment of Apical Extrusion during Root Canal Irrigation with the Novel GentleWave System in a Simulated Apical Environment.

INTRODUCTION: This study assessed apical extrusion during treatment with GentleWave (GW; Sonendo Inc, Laguna Hills, CA), a conventional open-ended 30-G needle (CN), or Endovac (EV; SybronEndo, Orange, CA) in root canals enlarged to different dimensions with and without apical constriction. METHODS: Sixteen mandibular molars were mounted in an in vitro apparatus. Roots were immersed in a pressure-regulated chamber containing distilled water with pressure kept at 5.88 ± 0.15 mm Hg to simulate periapical back pressure. Mesiobuccal (curved ≤30°) and distal (straight) canals were instrumented to the working length (WL) as follows: minimal instrumentation (MI, #15/.04), traditional instrumentation (#35/.06), or overinstrumentation (OI, #35/.06, to the WL + 1 mm). Canals were tested 5 times each with distilled water using GW, CN (at WL-3 mm), or EV and the mass (g) of extruded water recorded. Extrusion frequency and mean extruded mass were compared for each canal, irrigation group, and canal instrumentation mode (Wilcoxon t test, P < .05). RESULTS: No extrusion occurred with GW and EV, whereas the frequency of extrusion with CN was 33%. Mean extruded water mass using CN ranged in mesial canals from 0.000 ± 0.000 g (OI) to 0.047 ± 0.098 g (MI) and in distal canals from 0.123 ± 0.191 g (MI) to 0.505 ± 0.490 g (OI). With traditional instrumentation and OI instrumentation, extruded mass in distal canals was significantly higher than in mesial canals (P < .002) and distal canals with MI (P < .020). CONCLUSIONS: Within this study's limitations, root canal treatment with GW and irrigation with EV was not associated with extrusion. Extruded irrigation mass using the open-ended 30-G needle depended on the canal type and enlargement. These results have to be interpreted with caution, and further investigations are warranted to evaluate the possibility of extrusion using GW in different tooth types and clinical situations.

A systematic review of computer-assisted learning in endodontics education.

Results of the efficacy and time efficiency of computer-assisted learning (CAL) in endodontics education are mixed in the literature. The objectives of this study were to compare the efficacy and time efficiency of CAL with traditional learning methods or no instruction. The search strategy included electronic and manual searches of randomized controlled trials (RCTs) completed in English up to June 2009. The intervention comprised any method of CAL, while the control group consisted of all traditional methods of instruction including no further instructions. Various outcome measures of CAL efficacy were considered and were categorized using Kirkpatrick's four-level model of evaluation: reaction, learning, behavior, results, with the addition of return on investment as a fifth level. The time efficiency of CAL was measured by the time spent on the learning material and the number of cases covered in a unit period. Seven RCTs met the inclusion criteria. Overall, students' attitudes were varied towards CAL. Results from the knowledge gain outcome were mixed. No conclusions can be made about students' performance on clinical procedures or cost-effectiveness of CAL. Better time efficiency was achieved using CAL compared to traditional methods. CAL is as efficacious as traditional methods in improving knowledge. There is some evidence to suggest that CAL is time efficient compared to traditional methods. Overall, the number of studies included in this review was small, thus warranting the need for more studies in this area and the exploration of various CAL techniques.

Antibacterial efficacy of MTAD final rinse and two percent chlorhexidine gel medication in teeth with apical periodontitis: a randomized double-blinded clinical trial.

INTRODUCTION: Clinical assessment of the efficacy of novel root canal disinfection protocols is an important focus in endodontic research. This randomized double-blinded study assessed the antibacterial efficacy of a final rinse with BioPure MTAD (MTAD) and intracanal medication with 2% chlorhexidine gel (CHX) in teeth with apical periodontitis. METHODS: Canals in 30 teeth (single-rooted and multi-rooted) were prepared by using 1.3% NaOCl, rinsed with MTAD or saline in random sequence, medicated with CHX for 7 days, irrigated with 1.3% NaOCl, and filled. Bacteriologic root canal samples were obtained by aspiration before (1A) and after (1B) canal preparation, after the final rinse (1C), after CHX was flushed (2A), and after final irrigation (2B). Bacteria were enumerated by epifluorescence-microscopy (EFM) by using 2 staining methods and by colony-forming-unit (CFU) counts after 14 days of incubation. RESULTS: Bacterial counts (EFM) in 1B were greater than 95% decreased from 1A. Low bacterial densities in 1B, 1C, 2A, and 2B did not differ significantly from each other. EFM counts were consistently higher than CFU counts. CONCLUSIONS: The final rinse with MTAD and medication with CHX did not reduce bacterial counts beyond levels achieved by canal preparation with NaOCl.