Application of Real-time Augmented Reality-guided Osteotomy and Apex Location in Endodontic Microsurgery: A Surgical Simulation Study Based on 3D-printed Alveolar Bone Model

IntroductionAugmented reality (AR) is a novel visualization technique in which pregenerated virtual 3D content is superimposed on surgical sites. This study aimed to validate the viability of AR-guided endodontic microsurgery (ARG) and compare the changes in objective and subjective outcomes of surgical simulation using ARG and freehand (FH) endodontic microsurgery on customized 3D-printed models.MethodsWe created and printed a customized 3D alveolar bone model with artificial periapical lesions (APLs) based on cone-beam computed tomography. Eight models with 96 APLs were equally divided into ARG and FH groups. We planned surgical trajectories on rescanned printed models. Four inexperienced residents (IRs) performed ARG and FH on the models and completed pre and intraoperative confidence questionnaires for the subjective outcome. Postoperative cone-beam computed tomography scans of the models were reconstructed and analyzed, and all procedures were timed. We used pairwise Wilcoxon rank sum tests to compare objective outcomes. Kruskal–Wallis tests and post hoc pairwise Wilcoxon rank sum tests were used to compare subjective outcomes.ResultsCompared to the FH group, the ARG group significantly reduced deviation of the volume of bone removal, root-end resection, and deviation of bevel angle, with improved confidence of the IRs (P < .05); it also significantly increased surgical time and volume of unremoved APL (P < .05).ConclusionsWe customized an APL model through 3D printing and developed and validated a low-cost AR application framework, based on free AR software, for endodontic microsurgery. ARG allowed IRs to perform more conservative and precise surgical procedures with enhanced confidence.     

The Influence of Bone Tissue Deficiency on the Outcome of Endodontic Microsurgery: A Prospective Study

IntroductionThis study assessed the influence of deficiencies of the periapical and marginal bone tissue on clinical outcomes after endodontic microsurgery.MethodsData were collected from the Microscope Center of the Department of Conservative Dentistry at the Dental College of Yonsei University, Seoul, South Korea, between August 2004 and March 2011. In total, 199 teeth that required endodontic surgery were included in the study. During the surgical procedure, deficiencies of the periapical and marginal bone tissue were measured immediately before the flap was repositioned. The patients were recalled 6 months and 1 year after the surgical procedure to assess the clinical and radiographic signs of healing. The Student's t test or the Mann-Whitney U test and logistic regression were performed to evaluate the parameters. Significant associations between the outcome and all the evaluation parameters were analyzed using the Pearson chi-square test or the Fisher's exact test with a significance level of 0.05.ResultsA recall rate of 67.8% (135/199 teeth) was obtained. The height of the buccal bone plate was the only significant predictor (P = .040) of the healing outcome, suggesting that teeth with a buccal bone plate >3 mm presented a higher success rate than teeth with a buccal bone plate that was ≤3 mm high (94.3% vs 68.8%, P < .001).ConclusionsThese data suggest that a favorable prognosis can be expected when teeth are covered with a buccal bone plate that is >3 mm in height regardless of the amount of marginal bone loss.     

Retrospective Analysis of Root-end Microsurgery Outcomes in a Postgraduate Program in Endodontics Using Calcium Silicate–based Cements as Root-end Filling Materials

IntroductionThe purpose of this retrospective study was to determine the clinical and radiographic outcomes of root-end microsurgery in a postgraduate program in endodontics using modern techniques and calcium silicate–based root-end filling materials (ProRoot MTA; Dentsply International, Johnson City, TN, and EndoSequence Root Repair Material [ERRM]; Brasseler USA, Savannah, GA) and to identify any potential prognostic factors that may have affected healing outcomes.MethodsClinical records and periapical radiographs were collected from patients who had undergone endodontic microsurgery between 2007 and 2018 in a postgraduate endodontic clinic with a minimum follow-up interval of 6 months. Either ProRoot MTA or ERRM was used as the root-end filling material. Outcomes were categorized into healed, healing, and nonhealing based on clinical and radiographic findings. Healed and healing cases were pooled and considered as successes, whereas nonhealing cases were considered as failures.ResultsA total of 129 patients with 142 teeth were included in the final analysis. Seventy-six cases were root-end filled with ProRoot MTA and 66 root-end filled with ERRM. The ProRoot MTA group had a success rate of 92.1%, and the ERRM group had a success rate of 92.4% with no significant difference between the groups (P > .05). Vertical root fracture was found to be the predominant cause of failure. No patient- or treatment-related factor was identified to have any significant impact on healing.ConclusionsHigh overall success can be achieved in a postgraduate endodontic program when either ProRoot MTA or ERRM is used as the root-end filling material.     

Prognostic Factors after Endodontic Microsurgery: A Retrospective Study of 111 Cases with 5 to 9 Years of Follow-up

IntroductionA study was performed of the healing rate of teeth subjected to endodontic microsurgery after a minimum follow-up of 5 years with an analysis of the influence of different pre- and postoperative factors on the outcome.MethodsThis was a retrospective study of patients subjected to endodontic microsurgery with the use of mineral trioxide aggregate (MTA) for retrograde filling between January 2011 and December 2015. In patients with multiple treated teeth, only 1 random tooth was selected for the statistical analysis. Clinical and radiographic parameters were used to assess healing. Simple binary logistic regression models were used to analyze the influence of patient age and sex, the type of tooth, prior radiographic lesion size, the presence of a post, the type of restoration, and the apical extent of prior filling of the root canal on the endodontic microsurgery success rate. Two calibrated observers evaluated the periapical radiographs on an independent basis.ResultsA total of 111 patients (63.1% women and 36.9% men) were included in the study. Of the 111 teeth analyzed, 90 were classified as healed (mean healing rate = 81.1%). Patient age and sex, the presence of a post, the type of tooth, the type of restoration, and the apical extent of prior filling of the root canal had no significant impact on the outcome. Large lesions (>5 mm) were associated with a lower healing rate than smaller lesions, although the difference was not significant. Anterior teeth had a significantly higher healing rate (93.8% maxillary and 100% mandibular) than molars (70.8% maxillary and 57.1% mandibular) (P < .05). The differences between the anterior teeth and the molars were statistically significant.ConclusionsThe mean healing rate of teeth subjected to endodontic microsurgery was 81% after 5–9 years of follow-up. The success rate was lower for upper and lower molars than for teeth in the anterior zone, although the sample was small and further studies are needed to establish whether the type of tooth influences the treatment outcome.     

Healing of 295 Endodontic Microsurgery Cases After Long-Term (5-9 Years) Versus Middle-Term (1-4 Years) Follow-up

IntroductionSome evidence suggests that teeth treated with endodontic surgery and considered to have healed over the short term are seen to relapse when evaluated again after 3 or more years. However, long-term evidence is limited. This study compares healing after endodontic microsurgery over long-term (5–9 years) vs middle-term (1–4 years) follow-up and assesses the influence of different healing predictors over time.MethodsA retrospective study was made, comparing the endodontic microsurgery healing rates after 1–4 vs 5–9 years of follow-up. Healing was assessed based on clinical and radiographic parameters. Simple binary logistic regression models were used to analyze the influence of patient age and gender, the type of tooth, previous radiographic lesion size, apical extent of previous root canal filling, the presence of a post, type of restoration, and interproximal bone level upon the endodontic microsurgery healing rate. A sensitivity analysis was used excluding cases of vertical root fracture. Two calibrated observers independently evaluated the periapical radiographs.ResultsA total of 332 patients (60% women and 40% men) were included in the study. Of the 332 analyzed teeth, 198 were subjected to middle-term follow-up (1–4 years), with a healing rate of 86.9%, while 134 were subjected to long-term follow-up (5–9 years), with a healing rate of 67.2%. There were no statistically significant differences in terms of gender, age, type of tooth, size of the lesion, apical extent of previous root canal filling, presence of a post, or type of restoration. The regression models identified 2 statistically significant associations: cohort and interproximal bone level (P < .05).ConclusionsA success rate of 86.9% was recorded after 1-4 years of follow-up, vs 67.2% after 5–9 years. Excluding cases of vertical root fractures, in the shortest follow-up cohort (1–4 years), the healing rate was 92.5%, vs 82.6% in the cohort with longer follow-up (5–9 years). The prognosis was influenced by the crestal bone level in relation to the cementoenamel junction of the tooth, being significantly poorer when probing depth was >3 mm mesial or distal to the treated tooth.     

Evaluation of concentrated growth factor and blood clot as scaffolds in regenerative endodontic procedures: A retrospective study

The study aims to investigate and compare the success rate of concentrated growth factor (CGF) and blood clot (BC) as scaffolds in regenerative endodontic procedures (REPs). Immature permanent necrotic teeth treated by REPs with at least a 6-month follow-up were included. These teeth were divided into the CGF (53 teeth) and BC (68 teeth) groups. Treatment outcomes were assessed using a combined clinical and radiographic scoring system. The total success rate was 91.74% over a mean follow-up period of 23.15 months. There was no significant difference between the CGF group (86.79%) and BC group (95.59%). The success rate of traumatic teeth (84.31%) was significantly lower than that of teeth with developmental dental anomalies (98.39%) (p < 0.05). CGF may be a suitable alternative scaffold in REPs when adequate bleeding cannot be achieved. Moreover, compared to developmental dental anomalies, traumatic teeth treated by REPs may be more vulnerable to failure.     

Prognostic Predictors of Endodontic Microsurgery: Radiographic Assessment

ObjectiveThis study aimed to compare the healing outcomes of endodontic microsurgery (EMS) using 2-dimensional (2D) and 3-dimensional (3D) radiographic evaluation in a Chinese population. The prognostic factors of EMS were identified according to the 2D and 3D healing classifications.Materials and methodsThe teeth (n = 82) were studied using 2D and 3D radiographic examinations. The 2D and 3D healing criteria were used to evaluate the healing outcome. Prognostic factors were investigated based on healing outcomes. Data were analysed using SPSS, and P < .05 was considered significant.ResultsThere were significant differences between 2D and 3D healing outcomes (P = .004). For the 3D images, age older than 45 years was found to be a significant negative predictor (P = .005).ConclusionsCone-beam computed tomographic images provided more precise evaluation of periapical lesions and healing outcomes of EMS than conventional periapical radiographs. Age (>45 years) of the patients exhibited a significant influence on the healing outcome of EMS as determined using 3D images.     

Periapical healing after simplified endodontic treatments: A digital subtraction radiography study

AimTo evaluate the 6-month outcome of endodontic treatment of periapical lesions with integrated systems by clinical examination and digital subtraction radiography (DSR).MethodologyEighty-four patients with chronic periapical pathosis were randomly allocated to two groups and received endodontic treatment with Revo-S/One Step Obturator (G1, n = 41) or GTX/GTX Obturator (G2, n = 43). Six months later, clinical examination and DSR analysis were performed. Non-parametric statistical methods were used (p < 0.05).ResultsTotal healing, partial healing and failure occurred in 48.4%, 48.4% and 3.2% of cases in G1, in 50.0%, 43.8% and 6.2% of cases in G2, respectively. No significant difference was detected.ConclusionsThe integrated endodontic techniques allowed for a high 6-month success rate in both groups in accordance with literature data.     

Evaluation of Microsurgery with SuperEBA as Root-end Filling Material for Treating Post-treatment Endodontic Disease: A 2-year Retrospective Study

Introduction

This retrospective study assessed the effects of microsurgical treatment of post-treatment endodontic disease using SuperEBA (Bosworth, Skokie, IL) as the root-end filling material and evaluated the potential prognostic factors in relation to outcome.

Methods

Data were collected from patients diagnosed with post-treatment endodontic disease who then underwent endodontic microsurgery between April 2007 and October 2010. The effect was evaluated 2 years after the operation. Surgical procedures were performed by a single endodontic specialist. After surgery, operation records were recorded including preoperative, intraoperative, and postoperative factors from the clinical and radiographic measures. For statistical analysis of the predisposing factors, the dependent variable was the dichotomous outcome (ie, success vs failure).

Results

Eighty-two patients with 101 treated teeth met the inclusion criteria. The recall rate was 87.2%. Of these microsurgically treated cases, the overall healing rate was 93.1%. At the 0.05 significance level, age, sex, tooth position, size of periapical radiolucency, biopsy result of periapical lesion, and presence of a sinus tract appeared to have no significant effects on the outcome (P > .05).

Conclusions

Microsurgical endodontic treatment using SuperEBA as the root-end filling material is a favorable option for post-treatment endodontic disease.     

Outcome of Nonsurgical Root Canal Retreatment Procedures Obturated with Warm Gutta-percha Techniques: A Longitudinal Clinical Study

IntroductionTo evaluate the success rate of nonsurgical root canal retreatment at the 2–3-year follow-up and identify the possible prognostic factors.MethodsPatients who underwent root canal retreatment at a university dental clinic were contacted for clinical and radiographic follow-up. The retreatment outcomes in these cases were based on clinical signs, symptoms, and radiographic criteria. Inter- and intraexaminer concordances were calculated using Cohen's kappa coefficient. The retreatment outcome was dichotomized into success or failure according to strict and loose criteria. The radiographic success criteria consisted of complete resolution or absence of a periapical lesion (strict criteria) or a reduction in the size of an existing periapical lesion at recall (loose criteria). χ² tests were used to evaluate possible variables associated with retreatment outcomes (age, sex, tooth type, location, contact points, periapical status, quality of previous and final root canal filling, previous and final restoration, number of visits, and complications).ResultsOverall, 129 teeth (113 patients) were included in the final evaluation. The success rate was 80.6% under strict criteria and 93% under loose criteria. Molars, teeth with an initially higher periapical index score, and teeth with >5 mm periapical radiolucency had a lower success rate according to the strict criteria model (P < .05). When the loose success criteria were used, teeth with larger (>5 mm) periapical lesions and those that had been perforated during retreatment showed a lower success rate (P < .05).ConclusionsThe present study demonstrated that nonsurgical root canal retreatment is a highly successful procedure after an observation period of 2–3 years. Treatment success is primarily affected by the presence of large periapical lesions.     

Prevalence of Nonendodontic Diagnoses in Periapical Biopsies: A 6-year Institutional Experience

IntroductionThe purpose of this study was to identify nonendodontic periapical lesions (NPLs) mimicking endodontic pathosis, which are most frequently encountered by clinicians.MethodsA retrospective study was conducted on biopsies obtained from 2015–2020 at Texas A&M College of Dentistry’s oral pathology laboratory. The online database was screened for cases submitted as suspected endodontic pathology using specific key words. Histologic diagnoses were collected to determine the prevalence of NPLs that were originally thought to be of endodontic origin. The frequency and percentage of endodontic pathology and NPLs were documented.ResultsAmong 6704 biopsies clinically diagnosed as endodontic lesions, 190 (2.8%) were histopathologically diagnosed as NPLs. The most frequent NPLs were odontogenic keratocytes’ (n = 70, 36.8%), cemento-osseous dysplasia (n = 27, 14.2%), and dentigerous cysts (n = 22, 11.6%). Of all NPLs, 3.7% were malignant neoplasms, with the most common diagnosis being squamous cell carcinoma. Of 6514 endodontic histologic diagnoses, the prevalence of periapical granulomas and cysts was 60.2% (n = 3924) and 39.1% (n = 2549), respectively.ConclusionsAlthough most endodontic submissions are likely to be histologically diagnosed as periapical granulomas or cysts, the clinician should be aware that a small portion of these lesions may be nonendodontic in origin and possibly neoplastic in nature. Histopathologic evaluation of biopsied specimens is critical to achieve a proper diagnosis to ensure the appropriate management of patients.     

Regenerative Endodontic Procedures in Necrotic Mature Teeth with Periapical Radiolucencies: A Preliminary Randomized Clinical Study

IntroductionThis preliminary study compared clinical and radiographic outcomes of regenerative endodontic procedures (REPs) with that of conventional root canal treatment (CRCT) in necrotic mature teeth with periapical radiolucencies.MethodsFifty-six mature necrotic teeth with large periapical radiolucencies were distributed into 2 groups: group 1, REPs and group 2, CRCT (n = 28/group). Clinical and radiographic follow-up assessments were undertaken up to 12 months. Statistical analysis was performed using the independent samples t test and the chi-square test, and the level of significance was set at P = .05.ResultsWith a follow-up rate of about 73.4% of the total patients for 12 months, favorable clinical and radiographic outcomes were found in 92.3% and 80% in REPs and CRCT groups, respectively, and the difference was not statistically significant (P > .05). Half of the teeth treated with REPs responded to the electric pulp test.ConclusionsRegenerative endodontic procedures have the potential to be used as a treatment option for mature teeth with large periapical radiolucencies.     

Outcome of Regenerative Endodontic Procedures in Nonvital Immature Permanent Teeth Using 2 Intracanal Medications: A Prospective Randomized Clinical Study

IntroductionThis randomized clinical trial aimed to assess and compare the long-term clinical and radiographic outcomes of regenerative endodontic procedures (REPs) in treating nonvital immature permanent teeth using 2 intracanal medicaments.MethodsForty-five patients yielding a total of 50 anterior and posterior nonvital immature teeth were randomly divided into 2 groups. REPs using either nonsetting calcium hydroxide (Ca[OH]₂) (n = 25) or modified triple antibiotic paste (TAP) (n = 25) as intracanal medicaments were performed. NeoMTA Plus (Avalon Biomed Inc) was applied for coronal sealing. Cases were followed up clinically and radiographically for 36 months. The survival rate, success rate, and clinical outcome measures were analyzed. Preoperative and recall radiographs were evaluated for dimensional changes in root length, dentin thickness, apical diameter, and periapical radiolucency.ResultsAt the 36-month follow-up, the success and survival rates were 81.6% and 100%, respectively, in which 79.4% of cases showed complete resolution of periapical radiolucency with no significant difference between the nonsetting Ca(OH)₂ and modified TAP groups (P > .050). The cumulative changes in root length, root dentin thickness, and apical diameter throughout the study period were observed in 47.9%, 77.1%, and 89.6% of cases, respectively, with no significant differences between groups (P ≥ .39). Intracanal calcifications were detected in 60% of cases with no significant difference between groups (P = .77).ConclusionsREPs, using either nonsetting Ca(OH)₂ or modified TAP as the intracanal medicament, exhibited high success and survival rates over a follow-up period of 36 months with equally favorable clinical and radiographic outcome data.     

Clinical Outcome of Nonsurgical Root Canal Treatment Using a Matched Single-Cone Obturation Technique with a Calcium Hydroxide–based Sealer: A Retrospective Analysis

IntroductionThe aim of this retrospective study was to estimate the outcome of nonsurgical root canal treatment using matched single-cones with a calcium hydroxide–based sealer and to identify the various prognostic factors influencing the outcome.MethodsThis was a retrospective study that enrolled 272 patients who underwent routine endodontic therapy and were obturated with matched single-cones and Sealapex as sealer. This study involved 223 patients with 261 teeth meeting the selection criteria and recalled between 24 and 84 months. The outcome was categorized as success (healed/healing clinically and radiographically) or failure (not healed clinically and/or radiographically). Two calibrated examiners assessed the treatment outcomes. A binomial logistic regression model was performed to identify the effect of various prognostic factors. The χ² test was used to find the association between sealer extrusion and the initial periapical index scores.ResultsThe overall success rate was found to be 89.7% for a mean recall period of 39.18 (±11.05) months. An increase in age was associated with increased odds of success, whereas the success rates were reduced by an increase in the number of roots and negative pulp sensibility status. Initial periapical index scores, presence of preoperative sinus tract, number of visits, and sealer extrusion did not affect the outcome significantly (P > .05).ConclusionWithin the limitations of this study, it was found that teeth obturated with matched single-cone and Sealapex achieved substantial success rates. Sealer extrusion did not have any significant effect on the treatment outcome.     

Outcome of Endodontic Microsurgery Using Mineral Trioxide Aggregate or Root Repair Material as Root-end Filling Material: A Randomized Controlled Trial with Cone-beam Computed Tomographic Evaluation

IntroductionThe purpose of this randomized clinical trial was to evaluate healing after endodontic microsurgery (EMS) using mineral trioxide aggregate (MTA) versus EndoSequence root repair material (RRM; Brasseler, Savannah, GA) as root-end filling materials.MethodsTwo hundred forty-three teeth with persistent or recurrent apical periodontitis were randomly assigned to either the MTA or RRM group. EMS was performed, and follow-up visits with clinical and radiographic investigation were scheduled at 6, 12, and 24 months with follow-up cone-beam computed tomographic (CBCT) imaging after 12 months.ResultsOne hundred twenty teeth with an average follow-up of 15 months were evaluated. The overall success rate was 93.3% for periapical (PA) evaluation and 85% for CBCT evaluation. The RRM group exhibited 92% and 84% success rates as assessed on PA and CBCT imaging, respectively. The MTA group exhibited 94.7% and 86% success rates as assessed on PA and CBCT imaging, respectively. No significant difference was observed between the 2 groups. Microsurgical classification, root canal filling quality, root-end filling material depth, and root fracture were found to be significant outcome predictors.ConclusionsEMS is a predictable procedure with successful outcome both 2-dimensional and 3-dimensional radiographic evaluation when RRM or MTA was used as the root-end filling material.     

An Endodontic Forecasting Model Based on the Analysis of Preoperative Dental Radiographs: A Pilot Study on an Endodontic Predictive Deep Neural Network

IntroductionThis study aimed to evaluate the use of deep convolutional neural network (DCNN) algorithms to detect clinical features and predict the three-year outcome of endodontic treatment on preoperative periapical radiographs.MethodsA database of single-root premolars that received endodontic treatment or retreatment by endodontists with presence of three-year outcome was prepared (n = 598). We constructed a 17-layered DCNN with a self-attention layer (Periapical Radiograph Explanatory System with Self-Attention Network [PRESSAN-17]), and the model was trained, validated, and tested to 1) detect 7 clinical features, that is, full coverage restoration, presence of proximal teeth, coronal defect, root rest, canal visibility, previous root filling, and periapical radiolucency and 2) predict the three-year endodontic prognosis by analyzing preoperative periapical radiographs as an input. During the prognostication test, a conventional DCNN without a self-attention layer (residual neural network [RESNET]-18) was tested for comparison. Accuracy and area under the receiver-operating-characteristic curve were mainly evaluated for performance comparison. Gradient-weighted class activation mapping was used to visualize weighted heatmaps.ResultsPRESSAN-17 detected full coverage restoration (area under the receiver-operating-characteristic curve = 0.975), presence of proximal teeth (0.866), coronal defect (0.672), root rest (0.989), previous root filling (0.879), and periapical radiolucency (0.690) significantly, compared to the no-information rate (P < .05). Comparing the mean accuracy of 5-fold validation of 2 models, PRESSAN-17 (67.0%) showed a significant difference to RESNET-18 (63.4%, P < .05). Also, the area under average receiver-operating-characteristic of PRESSAN-17 was 0.638, which was significantly different compared to the no-information rate. Gradient-weighted class activation mapping demonstrated that PRESSAN-17 correctly identified clinical features.ConclusionsDeep convolutional neural networks can detect several clinical features in periapical radiographs accurately. Based on our findings, well-developed artificial intelligence can support clinical decisions related to endodontic treatments in dentists.     

Targeted Endodontic Microsurgery: A Retrospective Outcomes Assessment of 24 Cases

IntroductionTargeted endodontic microsurgery (TEMS) replaces freehand carbide or diamond bur osteotomy and root-end resection with a guided approach using an end-cutting trephine bur rotated within a guide tube. TEMS departs from traditional endodontic microsurgery in osteotomy size, control of resection level and bevel, surgical time, and resection method; yet, the impact of these departures on clinical outcomes has yet to be assessed. The aim of this study was to assess clinical outcomes of TEMS surgeries at least 1 year after treatment.MethodsPotential cases were retrospectively identified from a secure database of all patients who received TEMS in the Air Force Postgraduate Dental School from June 2017–May 2019 with a postsurgical follow-up examination at 1 year or beyond (23 patients with 24 teeth). Two board-certified endodontists completed a calibration exercise before assessing radiographs. A retrospective outcomes assessment was conducted considering follow-up clinical and radiographic findings to assign 1 of 3 healing designations: complete healing, reductive healing, or failure.ResultsCombined clinical and radiographic data led to 20 designations of complete healing, 2 designations of reductive healing, and 2 failures (91.7% success rate). Considered alone, radiographic criteria for complete healing were met for 20 cases, reductive healing for 3 cases, and radiographic failure for 1 case.ConclusionsThis limited retrospective outcomes assessment is an early indication that TEMS-guided trephine bur root-end resection leads to similar success as is established for freehand carbide and diamond bur resection. Controlled clinical trials with long-term follow-up are warranted.     

Outcomes of Nonsurgical Retreatment and Endodontic Surgery: A Systematic Review

IntroductionThe purpose of this systematic review was to compare the clinical and radiographic outcomes of nonsurgical retreatment with those of endodontic surgery to determine which modality offers more favorable outcomes.MethodsThe study began with targeted electronic searches of MEDLINE, PubMed, and Cochrane databases, followed with exhaustive hand searching and citation mining for all articles reporting clinical and/or radiographic outcomes for at least a mean follow-up of 2 years for these procedures. Pooled and weighted success rates were determined from a meta-analysis of the data abstracted from the articles.ResultsA significantly higher success rate was found for endodontic surgery at 2–4 years (77.8%) compared with nonsurgical retreatment for the same follow-up period (70.9%; P < .05). At 4–6 years, however, this relationship was reversed, with nonsurgical retreatment showing a higher success rate of 83.0% compared with 71.8% for endodontic surgery (P < .05). Insufficient numbers of articles were available to make comparisons after 6 years of follow-up period. Endodontic surgery studies showed a statistically significant decrease in success with each increasing follow-up interval (P < .05). The weighted success for 2–4 years was 77.8%, which declined at 4–6 years to 71.8% and further declined at 6+ years to 62.9% (P < .05). Conversely, the nonsurgical retreatment success rates demonstrated a statistically significant increase in weighted success from 2-4 years (70.9%) to 4–6 years (83.0%; P < .05).ConclusionsOn the basis of these results it appears that endodontic surgery offers more favorable initial success, but nonsurgical retreatment offers a more favorable long-term outcome.     

The Correlation of Crack Lines and Definitive Restorations with the Survival and Success Rates of Cracked Teeth: A Long-term Retrospective Clinical Study

IntroductionCracked teeth frequently require protective adhesive restorations. This long-term, longitudinal retrospective clinical study aimed to evaluate the factors influencing the success and survival rates of cracked teeth with crack lines (CLs) in different directions when restored early with onlays or full-coverage crowns.MethodsThe dental records of 71 patients with a total of 86 cracked teeth with different pulpal and periapical diagnoses and with follow-ups spanning over 1–11 years were included. Data regarding the demographics; clinical symptoms and signs; bruxism; occlusal interferences; eating habits; pulpal and periapical diagnoses; number, direction, location, and extent of CLs; probing depth; and coronary condition before and after the placement of definitive restorations were collected. Univariate associations between tooth survival and explanatory variables were assessed. The long-term survival rate was estimated using Kaplan-Meier analysis and the log-rank test. A multivariate analysis was performed using Cox regression analysis.ResultsThe overall success rate was 93.0%, and the overall survival estimates of cracked teeth restored early were 98.6%, 94.9%, and 55.9% at the 1-, 5-, and 11-year follow-ups, respectively. The direction of the CLs did not influence the survival of the tooth. No significant association was observed between the type of tooth, probing depth, root canal treatment, and tooth loss (P > .05). The multivariate analysis showed that previously treated cracked teeth (P < .05), the provision of onlay restorations (P < .05), and the placement of posts (P < .05) had higher correlations with tooth loss. Additionally, the placement of full-coverage crowns resulted in lower tooth loss compared with the placement of onlays (P < .05).ConclusionsPrevious endodontic treatment in teeth that subsequently develop CLs has a negative impact on the survival rate of the teeth. Moreover, early placement of full-coverage crowns should be implemented for cracked teeth regardless of the direction or the number of CLs because it is associated with a higher cracked tooth survival rate.     

A Cadaver-based Comparison of Sleeve-guided Implant-drill and Dynamic Navigation Osteotomy and Root-end Resections

IntroductionThis study compared the accuracy and efficiency of fully guided static and dynamic computer-assisted surgical navigation techniques for osteotomy and root-end resection (RER).MethodsFifty roots from cadaver heads were divided into two groups: fully guided static computer-assisted endodontic microsurgery (FG sCAEMS) and dynamic computer-assisted endodontic microsurgery (dCAEMS) (all, n = 25). Cone-beam computed tomography scans were taken pre and postoperatively. The osteotomy and RER were planned virtually in the preoperative cone-beam computed tomography scan and guided using 3D-printed surgical guides in the FG sCAEMS and 3D-dynamic navigation system in the dCAEMS. The 2D and 3D deviations and angular deflection were calculated. The osteotomy volume, resected root length, and resection angle were measured. The osteotomy and RER time and the number of procedural mishaps were recorded.ResultsFG sCAEMS was as accurate as dCAEMS, with no difference in the 2D and 3D deviation values or angular deflection (P > .05). The osteotomy and RER time were shortened using FG sCAEMS (P < .05). The FG sCAEMS showed a greater number of incomplete RERs than dCAEMS. Osteotomy volume, RER angle, and root length resected were similar in both groups (P > .05). FG sCAEMS and dCAEMS were feasible for osteotomy and RER.ConclusionsWithin the limitations of this cadaver-based study, FG sCAEMS was as accurate as dCAEMS. Both FG sCAEMS and dCAEMS were time-efficient for osteotomy and RER.