Clinician-centered Outcomes Assessment of Retreatment and Endodontic Microsurgery Using Cone-beam Computed Tomographic Volumetric Analysis

Two- and three-dimensional healing assessment after endodontic microsurgery in through-and-through periapical lesions: 5-year follow-up from a randomized controlled trial

AIM

To evaluate clinical and radiographic outcome of endodontic microsurgery in through-and-through periapical lesions at 1-year and 5-year follow-up with adjunct use of platelet-rich plasma (PRP).

METHODOLOGY

Thirty-two patients with large through-and-through periapical lesions were randomized in platelet-rich plasma (PRP) group and control group. Two-dimensional (2D) healing was evaluated with Molven's criteria and three-dimensional (3D) healing with modified PENN 3D criteria. Healing at resection plane (R), apical area (A), buccal cortex (BC), palatal cortex (PC) and overall bone healing (B) was assessed using CBCT scans. The volume of lesion was measured using ITK-Snap software. The analysis included comparison of 1- to 5-year intragroup (Friedman test/McNemar test) and intergroup scoring (Chi-square/ Mann-Whitney test). Logistic regression analysis was performed to determine the effect of various factors on healing at 5 years.

RESULTS

Out of 32 patients/59 teeth evaluated after 1-year of endodontic microsurgery, 24 patients/44 teeth reported at 5 - year follow-up. Healing assessment with modified PENN 3D criteria revealed improvement in overall success rate of 66.7% at 1 year to 83.3% at 5 years, with no deterioration in any healing category. PRP group exhibited significantly better 3D healing than control group; both at 1 year (84.6% vs. 45.5%) and 5 years (100% vs. 63.6%). A significantly higher number of completely healed teeth were observed in PRP group than the control group at 5 years with respect to R, BC and B parameters. A volume reduction of 88% (91.4% PRP, 84% control) was depicted at 1 year and 94% (97.1% PRP, 91.1% control) at 5 years. None of the recorded factors including age, gender, size of lesion, preoperative swelling and sinus, histology of lesion, use of PRP, tooth location, preoperative buccal bone had significant effect on 3D healing at 5 years.

CONCLUSIONS

This 5-year study suggested improvement in 3D radiographic healing of large through-and-through periapical lesions from 1 to 5 years with no deterioration in any healing parameter in both control and PRP groups. The additional use of PRP led to significantly better healing in such lesions. RACB index using CBCT allows better estimation of healing at resected, apical and cortical plane over modified PENN 3D or Molven's criteria.

Advancements in guided surgical endodontics: A scoping review of case report and case series and research implications

This scoping review examined current case series and reports on guided surgical endodontic applications in order to provide a critical platform for future research. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews guidelines were followed. A search on PubMed and Scopus yielded 611 articles, with 17 case reports and 1 series meeting inclusion criteria. Overall, guided surgery addressed anatomical complexities, with 15 articles employing static protocols and 3 dynamic. Results showed minimal iatrogenic errors and reduced chair time, with no postoperative issues reported. Within the cases described, guided endodontic surgery exhibited satisfactory results in management of anatomical complex cases. Cost-effectiveness, the need for adequate follow-up, procedure's reproducibility and accuracy, and objective measurement of the reduction in operative times and iatrogenic errors are some of the limitations in the current reports that need to be considered for planning of future experimental and cohort studies.

The trend of radiographic healing after root canal treatment in teeth with apical periodontitis based on cone-beam computed tomography: A 4-year longitudinal study

OBJECTIVES

The aim of this study was to observe the radiographic healing of periapical lesions after root canal treatment via volumetric measurements based on cone-beam computed tomography (CBCT) over 4 years.

METHODS

In total, 162 single-root teeth from patients with chronic periapical periodontitis who underwent primary root canal treatment were included in this retrospective study. Follow-up visits were scheduled at 1, 2, and 4 years after treatment. The volume of radiolucency at pretreatment and follow-up were measured, and the radiographic outcomes were classified into 4 categories: absence, reduction, uncertain or enlargement. Reduction or enlargement was considered when the volumetric change in radiolucency was 20 % or more.

RESULTS

During the 4-year follow-up period, 128 teeth were reviewed at least once, including 3 extracted teeth. Of the remaining 125 teeth, the volume of radiolucency was reduced in 116 teeth (90.6 %), uncertain in 5, and enlarged in 4 teeth during 1 to 4 years after treatment. Among the 43 teeth with reduced radiolucency at 1 year after treatment, 42 (97.7 %) had continuing reduced lesions at 4 years. In the 2 teeth with enlarged radiolucency at 1 year, the volume of radiolucency doubled at 4 years. Cox regression analysis revealed that the preoperative radiolucency size was a risk factor for persistent periapical radiolucency.

CONCLUSIONS

The efficacy of root canal treatment for apical periodontitis was predictable. When the radiolucency changed by 20 % or more in volume on CBCT scans at 1 year after treatment, reversal of the radiographic healing tendency was rare.

CLINICAL SIGNIFICANCE

The volumetric changes in radiolucency on CBCT could reflect trends in the healing process and may foster early clinical decision-making.

Accuracy comparison of single- and double-sleeve endodontic guides for fiber post removal

BACKGROUND

This study aimed to assess the accuracy of two different endodontic guides for fiber post removal.

METHODS

In this in vitro study, 54 maxillary canine fiber posts were mounted on 36 maxillary stone casts; 18 teeth were mounted unilaterally, and 36 teeth were mounted bilaterally. Static endodontic guides were fabricated according to baseline cone-beam computed tomography (CBCT) and intraoral optical scans using Blue Sky software. In the single-sleeve endodontic guides group (SSG), two anterior and two posterior teeth were included in a 5-unit guide. In the double-sleeve endodontic guides group (DSG) group, the guide was passed through the midline to include both canine teeth and extended by 2 teeth posterior to the canine teeth bilaterally (a 10-unit guide). After drilling, postoperative CBCT scans were taken and superimposed on the virtually designed path, and the maximum coronal deviation (MCD) at the marginal entry point of the tooth, maximum apical deviation (MAD) at 10 mm apical to the tooth margin, and maximum angular deflection (MAnD) of the drill were calculated.

RESULTS

The mean MCD, MAD, and MAnD were 0.34 mm, 0.6 mm, and 2.32 degrees, respectively, in the SSG and 0.31 mm, 0.7 mm, and 2.37 degrees, respectively, in the DSG. The two groups were not significantly different from each other in terms of MCD (P = 0.573), MAD (P = 0.290), or MAnD (P = 0.896).

CONCLUSIONS

The accuracies of the two techniques, the extended double sleeve guide and the single sleeve guide, were comparable and thus DSG may be used for removal of fiber posts in adjacent or distant teeth.

Non-surgical root canal treatment and retreatment versus apical surgery in treating apical periodontitis: A systematic review

BACKGROUND

In addition to non-surgical root canal treatment or retreatment, apical surgery may be carried out to manage teeth with apical periodontitis. However, it is unclear which treatment option is more effective.

OBJECTIVE

To systematically review the effectiveness of apical surgery compared with non-surgical treatment or retreatment in terms of clinical and patient-related outcomes in teeth with apical periodontitis.

METHODS

A literature search of electronic databases, the grey literature, the reference lists of included articles and previous reviews, and a hand search of leading endodontic journals, was conducted. Randomised and non-randomised control trials, and longitudinal observational studies on patients undergoing surgical (treatment group) and non-surgical root canal treatment or retreatment (control group) of teeth with apical periodontitis were included. The risk of bias was appraised using the Cochrane risk-of-bias tool; ROBINS-I and the Newcastle-Ottawa Scale.

RESULTS

Five studies, consisting of two randomised clinical trials, two non-randomised clinical trials, and a retrospective cohort study, were included. The interobserver agreement was high and kappa correlation coefficient was good. In total 529 teeth were available for follow-up that varied from 6 months to 8.7 years. The overall risk of bias was high for four studies and raised some concerns in one study. Apical surgery showed seemly better results regarding periapical healing and less need for more and further intervention, although tooth survival was higher in the control group. Given the heterogeneity of the studies, meta-analysis was not possible.

DISCUSSION

Previous systematic reviews have conducted an indirect comparison by separately pooling the outcomes of studies analysing either non-surgical, or surgical, treatment. In this systematic review, only studies that compared both treatments were included. Most results of this and previous reviews were similar.

CONCLUSION

No treatment option showed clear superiority. However, to arrive at statistically supported conclusions there is a need for additional high-quality comparative trials.

REGISTRATION

PROSPERO database (Registration number CRD42021260300).

Clinical and radiological outcomes of dynamic navigation in endodontic microsurgery: a prospective study

OBJECTIVES

This study was aimed at evaluating the clinical and radiological outcomes of novel dynamic navigation (DN)-aided endodontic microsurgery (EMS), with an analysis of potential prognostic factors.

MATERIALS AND METHODS

Forty-six teeth from 32 patients who received DN-aided EMS were included. Clinical and radiographic assessments were performed at least 1 year postoperatively. Two calibrated endodontists assessed radiological outcomes according to two-dimensional (2D) periapical radiography (PA) and three-dimensional (3D) cone-beam computed tomography (CBCT) imaging using Rud's and Molven's criteria and modified PENN 3D criteria, respectively. Fisher's exact test was used for statistical analysis of the predisposing factors.

RESULTS

Of the 32 patients with 46 treated teeth, 28 with 40 teeth were available for follow-up. Of the 28 patients, four (five teeth) refused to undergo CBCT and only underwent clinical and PA examinations, and the remaining 24 (35 teeth) underwent clinical, PA, and CBCT examinations. Combined clinical and radiographic data revealed a 95% (38/40) success rate in 2D healing evaluations and a 94.3% (33/35) success rate in 3D healing evaluations. No significant effect was found in sex, age, tooth type, arch type, preoperative lesion volume, preoperative maximum lesion size, presence/absence of crown and post, and the root canal filling state on the outcome of DN-aided EMS.

CONCLUSIONS

DN-aided EMS has a favorable prognosis and could be considered an effective and reliable treatment strategy. Further investigations with larger sample sizes are required to confirm these results.

CLINICAL RELEVANCE

DN-aided EMS could be considered an effective and reliable treatment strategy.

The effect of periapical lesion size on the success rate of different endodontic treatments: a systematic review and meta-analysis

INTRODUCTION

This systematic review evaluated the effect of periapical lesion (PL) size on the success rate of different endodontic treatments, including root canal treatment (RCT), non-surgical retreatment (NSR), and apical surgery (AS).

METHODS

Cohorts and randomized controlled trials investigating the outcomes of endodontic treatment of permanent teeth with PL and its size were identified electronically through Web of Science, MEDLINE, Scopus, and Embase databases. Two reviewers independently conducted the study selection, data extraction, and critical appraisal process. The quality of the included studies was evaluated using the Newcastle-Ottawa Scale and the 11-item Critical Appraisal Skills Program checklist for randomized controlled trials. The success rates of the endodontic treatments (small lesions and large lesions) were estimated using the rate ratios (RRs) with an associated 95% confidence interval (CI).

RESULTS

Out of 44 included studies, 42 were cohort, and 2 were randomized controlled trials. Thirty-two studies had poor quality. For the meta-analysis, five studies in RCT, 4 in NSR, and 3 in AS were considered. The RR of the endodontic treatment success in PLs was 1.04 in RCT (95% CI, 0.99-1.07), 1.11 in NSR (95% CI, 0.99-1.24), and 1.06 in AS (95% CI, 0.97-1.16). Only sub-group analysis of long-term follow-up of RCT showed a significantly higher success rate in small lesions than in large lesions.

CONCLUSIONS

Considering the quality of studies and variation in outcomes and size classification, our meta-analysis demonstrated that the PL size had no significant effect on the success rate of different endodontic treatments.

Outcomes of endodontic microsurgery using different calcium silicate-based retrograde filling materials: a cohort retrospective cone-beam computed tomographic analysis

PURPOSE

To evaluate the outcomes of endodontic microsurgery (EMS) using mineral trioxide aggregate (MTA; Dentsply Sirona, Charlotte, NC, USA), EndoSequence root repair material (RRM putty; Brasseler, Savannah, GA), and injectable Bioceramic (BC) sealer (Brasseler USA) followed by the application of RRM putty (lid technique) as root-end filling materials.

METHODS

One hundred and ten patients who underwent EMS between 2016 and 2020 at King Abdulaziz University Dental Hospital were recruited for clinical and radiographic follow-up after a minimum of 1 year. Radiographic assessment was performed using periapical radiographs (PAs) and cone-beam computed tomography (CBCT). Volumetric analysis of periapical radiolucencies (PARLs) was performed using Amira software.

RESULTS

Seventy-nine patients (103 teeth: MTA group, n = 28; RRM putty, n = 41; lid technique, n = 34), attended the follow-up visit, with an average follow-up period of 24 months (recall rate = 74.5%). Of the 103 teeth, 40 were anteriors, 24 were premolars, and 39 were molars. All three groups of retrograde filling materials (MTA, RRM putty, and lid technique) showed high success rates on both PA (85.7, 85.4, 94.1%, respectively) and CBCT imaging (67.9, 75.6, 88.2%, respectively), without any significant difference among the success rates of different materials. Overall, a slight agreement was noted between the PA and CBCT outcomes, with a statistically significant difference (P = 0.029). None of the patient-, tooth-, or treatment-related factors significantly influenced the outcomes of EMS. Adequate density of root canal filling material was significantly associated with a high percentage of completely healed cases on CBCT (P = 0.044). PARL volumes were reduced significantly over 1-4 years follow-up after EMS (P < 0.001) CONCLUSIONS: EMS showed high success rates on both PA and CBCT when MTA, RRM putty or lid technique were used as retrograde filling materials. CBCT imaging is more precise than PA in detecting the healing outcomes of EMS.

Outcome and associated predictors for nonsurgical management of large cyst-like periapical lesions: A CBCT-based prospective cohort study

AIM

The aim of this cone-beam computed tomography (CBCT)-based study was to evaluate the outcome of nonsurgical root canal treatment (RCT) performed for the management of large cyst-like periapical lesions (LCPL) and to identify the predictive factors affecting healing.

METHODOLOGY

Fifty-four subjects (77 permanent maxillary anterior teeth) with LCPL (>10 mm) of endodontic origin were included. A single operator performed standardized multi-visit RCT. Patients were clinically and radiographically examined at 6, 12 months, and a CBCT scan was taken at 24 months. Two independent blinded evaluators measured the pre- and postoperative volume of periapical lesions on CBCT scans using ITK snap software (version 3.8.0-beta-20181028-win64). The outcome was assessed as a percentage change in lesion volume and dichotomized as success (resolved/reduced) or failure (unchanged/enlarged). Ten preoperative (gender; age; intraoral draining sinus, soft tissue swelling, tooth discoloration, pulp canal obliteration, open apex, root resorption, cortical bone defect and lesion volume) and four intraoperative (apical extent and density of root filling; number of treatment visits and type of root filling) predictive factors were observed. Bivariate and stepwise multivariable linear regression analysis was performed to identify independent predictors affecting treatment outcomes. The significance level was set at 5%.

RESULTS

A recall rate of 88% was achieved. The success rate of RCT was 82.2% (8.9% resolved, 73.3% reduced). Median lesion volume reduction was 75% (IQR 61%-93%). No pre- or intra-operative factors were related to treatment failure. However, presence of preoperative cortical bone defect (palatal versus no cortical defect, β = -51.5; 95% CI: -86.9 to -16, p = .006) and apical extent of obturation (long versus flush, β = -27.2; 95% CI: -53.8 to -0.6, p = .04) were negatively associated with reduction in lesion volume (%).

CONCLUSION

Large cyst-like periapical lesions may be successfully managed with RCT. Preoperative cortical bone defect and apical extent of obturation may negatively influence osseous healing.

Comparison of Endodontic Failures between Nonsurgical Retreatment and Endodontic Surgery: Systematic Review and Meta-Analysis with Trial Sequential Analysis

Background and Objectives: In the presence of a persistent endodontic lesion or endodontic failure, the alternative for the recovery of the dental element is endodontic retreatment or endodontic surgery, which consists in the surgical removal of the root apices with retrograde closure of the endodontium. The objective of this systematic review and meta-analysis was to provide an updated value of the Risk Ratio between the two types of treatment in order to offer to clinicians who propose a non-surgical endodontic retreatment or an endodontic surgery a direct comparison. Materials and Methods: The revision was performed according to PRISMA indications: three databases (PubMed, Scopus and Cochrane register) were consulted through the use of keywords relevant to the revision topic: surgical endodontic retreatment, endodontic retreatment, apicoectomy. This search produced 7568 records which, after eliminating duplicates and applying the inclusion and exclusion criteria, resulted in a total of seven included articles. The meta-analyses were conducted by applying fixed-effects models, given the low percentage of heterogeneity. In addition, trial sequency analysis (TSA) was performed for the analysis of the statistical power of the results and GRADE for the quality of the evidence. Results: The results of the meta-analyses’ data report an aggregate risk ratio (RR) between non-surgical endodontic retreatment and surgical endodontic retreatment of: 1.05 [0.74, 1.47] at one year of follow-up; RR 2.22 [1.45, 3.41] at two years of follow-up; an RR 1.08 [0.73 1.62] for a follow-up period of 3–4 years; and an RR 0.92 [0.53, 1.61] for a follow-up period of 8–10 years. Conclusions: The results of the present meta-analysis show that in the long term, the risk of failure is identical for the two groups, and there is only a slightly higher risk of failure for non-surgical endodontic retreatments, when only two years of follow-up are considered.

Present Status and Future Directions - Surgical Endodontics

Endodontic surgery encompasses several procedures for the treatment of teeth with a history of failed root canal treatment, such as root-end surgery, crown- and root resections, surgical perforation repair, and intentional replantation. Endodontic microsurgery is the evolution of the traditional apicoectomy techniques and incorporates high magnification, ultrasonic root-end preparation and root-end filling with biocompatible filling materials. Modern endodontic surgery uses the dental operating microscope, incorporates cone-beam computed tomography (CBCT) for preoperative diagnosis and treatment planning, and has adopted piezoelectric approaches to osteotomy and root manipulation. Crown- and root resection techniques have benefitted from the same technological advances. This review focuses on the current state of root-end surgery by comparing the techniques and materials applied during endodontic microsurgery to the most widely used earlier methods and materials. The most recent additions to the clinical protocol and technical improvements are discussed, and an outlook on future directions is given. While non-surgical retreatment remains the first choice to address most cases with a history of endodontic failure, modern endodontic microsurgery has become a predictable and minimally invasive alternative for the retention of natural teeth.

Prognostic Predictors of Endodontic Microsurgery: Radiographic Assessment

Objective

This 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 methods

The 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.

Results

There 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).

Conclusions

Cone-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.

Diagnosis Efficacy of Cone-Beam Computed Tomography in Endodontics—A Systematic Review of High-Level-Evidence Studies

Introduction: The integration of clinical inspection and diagnostic imaging forms the basis for endodontic diagnosis, decision making, treatment planning, and outcome assessments. In recent years, CBCT imaging has become a common diagnostic tool in endodontics. CBCT should only be used to ensure that the benefits to the patient exceed the risks. As such, our aim in this study was to evaluate the high level diagnostic efficacy studies and their risk of bias. Methods: A systematic search of the literature was conducted to identify studies evaluating the use of CBCT imaging in endodontics. The following databases were searched: Medline (PubMed), Scopus, and Cochrane Central. The identified studies were subjected to rigorous inclusion criteria. Studies considered as having a high efficacy level were then subjected to a risk of bias assessment using the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. Results: Initially, 1568 articles were identified for possible inclusion in the review. Following title and abstract assessment, duplicate removal, and a full-text evaluation, 22 studies were included. Of those studies, 2 had a low risk of bias and 20 had a high risk of bias. Six studies investigated non-surgical treatment, eight investigated surgical treatment, two investigated both non-surgical and surgical treatment, and six studies investigated diagnostic thinking or decision making. Conclusion: The evidence for the influence of CBCT on decision making and treatment outcomes in endodontics is predominantly based on studies with a high risk of bias.

A prospective cohort study evaluating the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions

AIM

To evaluate the impact of various predictors on the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions after a minimum of 2 years.

METHODOLOGY

One hundred and twenty previously root canal treated symptomatic mandibular first molars with periapical lesions which were diagnosed as symptomatic apical periodontitis or acute apical abscess with localized intraoral swelling were included. Root canal retreatment was performed by an experienced endodontist using a standardized treatment protocol. The teeth were followed up clinically and radiographically and the radiographic outcome was assessed using a modified periapical index scale (PAI). The cumulative success proportion and the influence of predictors on the outcome of the root canal retreatment were analysed using Kaplan-Meier analyses and log-rank tests, and the hazard ratios for the predictors were also investigated using Univariate Cox Proportional Hazard regression analysis at a significance level of 5%.

RESULTS

Of the 120 teeth, 103 teeth were re-examined with an 85% recall rate. The cumulative success rate was 88% in which 64% were healed and 24% were healing, and failure rate was recorded as 12%. None of the preoperative predictors, including age, gender, soft tissue tenderness, intraoral swelling, size of the lesion, PAI score, apical level and density of root canal filling before root canal retreatment, nor intraoperative predictors, such as active exudate drainage, density of root canal filling after root canal retreatment and restoration type had an influence on the outcome of root canal retreatment (p > .05). The only factor that significantly reduced the success rate of root canal retreatment was the apical level of the root canal filling; when it was more than 2 mm short of the radiographic apex in teeth where apical patency was not established, the success was significantly lower (p = .023).

CONCLUSIONS

Root canal retreatment in symptomatic mandibular first molars with periapical lesions resulted in a success rate of 88%. None of the predictors had a significant influence on the outcome, except for the apical level of the root canal filling after root canal retreatment with short root fillings being associated with significantly more post-treatment endodontic disease.

Endodontic Retreatment Using Dynamic Navigation: A Case Report

INTRODUCTION

Dynamic navigation systems are used in dental implantology to optimize the accuracy of dental implant placement.

METHODS

A 30-year-old man was seen at the endodontic clinic of the Universidad Autónoma de Yucatán for pain in the left maxillary lateral incisor. A previously treated tooth with symptomatic apical periodontitis was diagnosed. The patient accepted treatment, and after signing an informed consent form, minimally invasive coronal access was performed through a zirconia crown. Then a post removal was performed with an ultrasonic tip to 2 mm before the apical gutta-percha limit, and the removal of material was completed manually with a K-file.

RESULTS

This case report demonstrates the use of dynamic navigation to remove a post from under a zirconia crown for the retreatment of a failing root canal procedure. The removal of fiber posts from endodontically treated teeth can present a unique challenge for clinicians. Numerous techniques and instrument kits are recommended for the removal of fiber posts, but the risk of excessive root structure damage is a major concern because the ability to differentiate the color difference between peripheral dentin and a bonded fiber post can complicate the accuracy of the removal.

CONCLUSIONS

The dynamic navigation system enabled minimally invasive removal of the fiber post with a high degree of accuracy, thus ensuring that there was no unnecessary removal of root structure. Dynamic navigation using real-time monitoring could reduce the attendant risk of iatrogenic errors in complex treatment cases.

Targeted Endodontic Microsurgery: A Retrospective Outcomes Assessment of 24 Cases

INTRODUCTION

Targeted 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.

METHODS

Potential 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.

RESULTS

Combined 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.

CONCLUSIONS

This 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.

Four-year Outcome of Nonsurgical Root Canal Retreatment Using Cone-beam Computed Tomography: A Prospective Cohort Study

INTRODUCTION

The purpose of this prospective study was to investigate the 4-year outcome and prognostic factors of nonsurgical root canal retreatment determined by measuring the volumetric change of periapical radiolucencies on cone-beam computed tomographic (CBCT) scans.

METHODS

Ninety-seven endodontically treated teeth from 80 patients diagnosed as apical periodontitis and indicated for root canal retreatment were included. Retreatment was performed by 7 endodontic specialists using a standardized treatment protocol. The teeth were reexamined clinically and radiographically 48-67 months after retreatment. The volume of preoperative and postoperative periapical radiolucencies on CBCT images was independently measured by 2 examiners. Radiographic outcome is presented in 4 categories: absence, reduction, enlargement, or unchanged. Reduction or enlargement was determined when the volumetric change of radiolucency was 20% or more. Multivariate logistic regression was performed for predictor analysis.

RESULTS

Sixty-two teeth (63.9%) from 50 patients returned for follow-up. Fifty-eight teeth were included in the prognostic analysis, all of which were symptom free. The 4 remaining teeth that had been extracted because of fracture were excluded. The total volume of periapical radiolucencies at 4 years postoperatively decreased by 94.6% compared with that preoperatively (P < .001), with an average reduction of 83.4% (95% confidence interval, 69.2%-97.5%). The periapical radiolucencies were determined as absence in 44 teeth (75.9%), reduction in 10 teeth (17.2%), unchanged in 1 tooth (1.7%), and enlargement in 3 teeth (5.2%). Tooth type was identified as an outcome predictor (P < .05).

CONCLUSIONS

The 4-year outcome of endodontic retreatment is predictable, with a significant volumetric reduction in periapical radiolucencies.

The Buffalo study: Outcome and associated predictors in endodontic microsurgery- a cohort study

AIM

To (i) evaluate and compare the outcome of endodontic microsurgery (EMS) using periapical radiographs (PAs) and cone-beam computed tomography (CBCT) scans; (ii) identify prognostic factors affecting the outcome; and (iii) correlate the effect of guided tissue regeneration (GTR) on the pattern of apical bone remodelling.

METHODOLOGY

Eighty-two patients (101 teeth) who received EMS were included and followed-up using clinical and radiographic examinations (PAs and CBCT scans). Two calibrated endodontists evaluated the radiographic healing (favourable or unfavourable) by assessing PAs and CBCT. The success (favourable radiographic outcome with no clinical symptoms) and survival rates (tooth retention without clinical symptoms) were calculated, and the cause of failure (diseased or fractured) was identified. Pre-treatment (age, sex, tooth type, position, sequence of treatment, quality of root canal before surgery, presence/absence of through-and-through lesion, presence/absence apico-marginal defect) and treatment (presence/absence of errors during surgery, type of error (major or minor), retro-preparation depth, presence/absence of an isthmus, retro-filling material used, presence/absence bone graft material and/or resorbable membrane) factors were recorded. Data were analysed statistically to determine the inter-observer, intra-observer and inter-radiographic agreements. Univariate, bivariate and logistic regression analysis were used to determine prognostic factors affecting the outcome and the effect of GTR on the pattern of apical bone remodelling. The significance level was set at 5%.

RESULTS

Sixty-eight patients (83 teeth) presented for outcome evaluation (recall rate: 84%). The survival rate was 93%. The success rate was 88% using PA and 86% using CBCT when vertical root fracture (VRF) cases were included and 94% using PAs, and 91% using CBCT when VRF cases were excluded. The intra- and inter-observer agreements were substantial using CBCT, slight to a fair agreement using PA (P < 0.001), and slight to moderate for inter-radiographic agreement. The occurence of a major procedural error during surgery was the only negative predictor for the outcome of EMS (P = 0.013). GTR did not affect the success rate or the type of healing when assessed using PA but it affected the type of healing on CBCT scans (complete vs incomplete healing) and the pattern of cortical plate remodelling (P < 0.001).

CONCLUSION

The success and survival rate of endodontic microsurgery was very high, and the occurrence of a major procedural error during surgery was the only factor affecting the outcome. GTR did not improve the outcome, but did affect the quality of apical bone remodelling following EMS.

Long-Term Prognosis of Endodontic Microsurgery-A Systematic Review and Meta-Analysis

Background and objectives: The long-term outcome of endodontic microsurgery (EMS) performed on root-filled teeth affected by post-treatment apical periodontitis (AP) has been a matter of debate, re-launched by the introduction of novel root-end filling materials which have been proven to improve the short-term outcome of EMS. The purpose of this systematic review and meta-analysis is to evaluate the clinical and radiographic long-term outcome of endodontic microsurgery in teeth diagnosed with secondary AP through radiographic evaluation. Materials and Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion and exclusion criteria were defined a priori to select the best longitudinal evidence. Only randomized clinical trials (RCT) and prospective clinical studies (PCS), with a follow-up ≥ 2-year, and exhibiting well-established clinical and radiographic outcome criteria, were selected. Results: A total of 573 articles were obtained, from which 10 fulfill inclusion criteria: 6 PCS and 4 RCT. Meta-analysis showed a pooled proportion of success rate of 91.3%, from an overall amount of 453 treated teeth included in RCT; from overall 839 included teeth in PCS, a pooled success rate of 78.4% was observed, with the follow-up time ranging from 2 to 13-years. Survival rate outcomes varied from 79 to 100% for the same follow-up period. Five prognostic factors with influence on the outcome were disclosed: smoking habits, tooth location and type, absence/presence of dentinal defects, interproximal bone level, and root-end filling material. Conclusions: High success rates and predictable results can be expected when EMS is performed by trained endodontists, allowing good prognosis and preservation of teeth affected by secondary AP.