Long-term Outcome of the Cases Classified as Successes Based on Short-term Follow-up in Endodontic Microsurgery

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.

Accuracy and efficiency of dynamic navigated root-end resection in endodontic surgery: a pilot in vitro study

BACKGROUND

The operation accuracy and efficiency of dynamic navigated endodontic surgery were evaluated through in vitro experiments. This study provides a reference for future clinical application of dynamic navigation systems in endodontic surgery.

MATERIALS AND METHODS

3D-printed maxillary anterior teeth were used in the preparation of models for endodontic surgery. Endodontic surgery was performed with and without dynamic navigation by an operator who was proficient in dynamic navigation technology but had no experience in endodontic surgery. Optical scanning data were applied to evaluate the length and angle deviations of root-end resection. And the operation time was recorded. T tests were used to analyze the effect of dynamic navigation technology on the accuracy and duration of endodontic surgery.

RESULTS

With dynamic navigation, the root-end resection length deviation was 0.46 ± 0.06 mm, the angle deviation was 2.45 ± 0.96°, and the operation time was 187 ± 22.97 s. Without dynamic navigation, the root-end resection length deviation was 1.20 ± 0.92 mm, the angle deviation was 16.20 ± 9.59°, and the operation time was 247 ± 61.47 s. Less deviation was achieved and less operation time was spent with than without dynamic navigation (P < 0.01).

CONCLUSION

The application of a dynamic navigation system in endodontic surgery can improve the accuracy and efficiency significantly for operators without surgical experience and reduce the operation time.

Periapical healing following endodontic microsurgery with collagen-based bone-filling material: A randomized controlled clinical trial

AIM

To evaluate two- and three-dimensionally the effect of resorbable collagen-based bone-filling material on periapical healing of endodontic lesions with four-wall defects following endodontic microsurgery (EMS).

METHODOLOGY

This parallel, randomized controlled superiority clinical trial involved 86 lesions with the strictly endodontic origin and four-wall defect morphology. EMS procedures were performed by calibrated postgraduate residents. Before flap closure, osteotomies were randomized to the control or treatment group. In the control group, the flap was repositioned with no material added. In the treatment group, a collagen-based bone-filling augmentation material was placed into the osteotomy. Clinical and radiographic examinations were completed after 12 months. Periapical healing was evaluated by blinded evaluators using periapical (PA) radiographs according to Molven's criteria and cone beam computed tomography (CBCT) scans according to PENN's 3D criteria. Cortical plate healing was scored according to the RAC/B index. The data were analysed using Fisher's exact test, Logistic regression models and Chi-squared test. The significance level was predetermined at p < .05.

RESULTS

Sixty-six cases were evaluated at the 12-month follow-up, with 30 and 36 cases in the control and treatment groups, respectively. Only the asymptomatic cases (control = 26, treatment = 32) were included in the radiographic evaluation. Twenty-three cases (88.5%) in the control and 28 (87.5%) cases in the treatment group demonstrated complete healing on PA radiographs (p = 1.000). On CBCT, 10 (38.4%) and 21 (65.6%) cases had completely healed in the control and treatment groups, respectively (p = .095). The re-establishment of the buccal cortical plate was detected in 12 (46.2%) and 22 (68.8%) cases in the control and treatment groups, respectively (p = .243).

CONCLUSION

Within the limitations of the present study, the use of collagen-based bone-filling material had no statistically significant effect on the periapical healing of endodontic lesions with four-wall defect following EMS at the 12-month follow-up when evaluated by PA radiographs or CBCT scans. However, the observed higher percentage of a re-established cortical plate in the treatment group could suggest a clinical benefit that is of interest after surgical endodontic treatment.

The effect of hard tissue defects on the clinical outcome of endodontic microsurgery: a systematic review and meta-analysis

OBJECTIVES

The purpose of this systematic review was to appraise the existing literature on the effect of hard tissue defects on the clinical outcome of endodontic microsurgery (EMS).

METHODS

MEDLINE (PubMed), Embase, Web of Science, Cochrane Library and grey literature were searched from January 2000 to May 2023. Study selection and data extraction were performed in duplicate. Eligible studies were critically appraised for the risk of bias using the Cochrane Risk of bias tool. The quality of evidence was assessed using GRADE. Review Manager (RevMan Computer program Version 5.4, The Cochrane Collaboration, 2020) was utilized and the Mantel Haenszel fixed or random effects model was applied, depending on the heterogeneity of the studies. Meta-analysis was performed to estimate the Risk ratio (RR) and 95% Confidence Interval (CIs) to correlate the effects of these factors on treatment outcomes.

RESULTS

Nineteen studies were included. The EMS overall pooled success rate was 84.5%. Five characteristics of hard tissue were identified. The size of the lesion (Small ≤ 5 mm: 78.4% vs. Large > 5 mm: 63.3%, RR = 1.12, 95% CI 1.00-1.26, P ≤ .05), significantly affected the outcomes of EMS. Endodontic lesions exhibited slightly better outcomes than endodontic-periodontal lesions (81.4% vs. 68.2%, RR = 1.14 95% CI 0.98-1.33, P > .05). Cases with the height of the buccal bone > 3 mm also exhibited slightly better outcomes (91.5% vs. 71.4%, RR = 1.20, 95% CI 0.88-1.62, P > .05). Additionally, through and through lesions exhibited better outcomes when grafting was completed during the EMS procedure both in 2D (RR = 1.12 95% CI 0.97-1.29, P > .05) and 3D evaluation ((RR = 1.28 95% CI 0.69-2.37 P > .05). The overall quality of evidence was graded as low to high.

CONCLUSION

With a low to high quality of evidence, the size of the lesion is a key prognostic variable that significantly affects the outcome of EMS, as lesions ≤ 5 mm exhibit better outcomes as compared to larger lesions.

CLINICAL SIGNIFICANCE

The presence of hard tissue defects can affect the outcome of endodontic microsurgery (EMS). The presented data can aid the clinicians' decision-making process by examining certain pre-operative prognostic variables, when considering EMS as a treatment option. Clinical cases with more favorable hard tissue characteristics lead to a better prognosis in EMS.

Factors that influence the outcomes of surgical endodontic treatment

Surgical endodontic treatment encompasses a broad spectrum of procedures, amongst which root-end cavity preparation and filling, retrograde root canal treatment and through-and-through endodontic surgery, may be classified under the umbrella term 'Root-end surgery'. This narrative review considers the available data on periapical healing, soft tissue healing, tooth survival and oral health-related quality of life (OHRQoL), following root-end surgery and the factors that affect its outcomes. The pooled periapical healed rate for the studies published up to 2021 was 69% (95% CI: 65%, 73%) but increased to 76% (95% CI: 66%, 86%) when only data from the 2020's studies were analysed. The prognostic factors consistently reported for periapical healing have included: pre-operative periapical lesion with complete loss of buccal plate, quality of root-end preparation, remaining thickness of apical root dentine and restorative status. Soft tissue healing of the reflected flap was found to have a positive association with periapical healing. The survival rates following root-end surgery range from 48% to 93%, with failure of periapical healing associated with root and crown fracture, being the predominant reasons for tooth extraction. The factors influencing impact of root-end surgery on patients' quality of life could not be adequately evaluated due to design flaws in the available studies. In conclusion, if root canal treatment failure due to leakage through cracks, fractures or restoration margin are excluded, the remaining cases may represent localized residual infection and inflammation at the periapex that should be amenable to predictable management with the aid of modern root-end surgery.

Buccal plate thickness as a predictor for endodontic microsurgery outcomes: A retrospective cohort study

OBJECTIVE

The aim of the study was to determine the relationship between preoperative buccal plate thickness (BPT) and radiographic healing at the osteotomy site after endodontic microsurgery (EMS) with and without guided tissue regeneration (GTR) using cone beam computed tomography (CBCT) imaging.

STUDY DESIGN

The retrospective sample of 143 individuals who had EMS with pre- and postoperative CBCT scans available were divided into 2 groups: group 1 (GTR) and group 2 (no GTR), which were further divided into teeth where BPT was >1.0 mm or ≤1.0 mm. Bone healing was assessed by subjective evaluation of bone formation at the resected root surface (I₁), periapical bone formation (I₂), cortical plate formation (I₃), and a derived index (Author2-Author1 Indices) (I₄), calculated by a composite score of I₁ and I₂.

RESULTS

There was no significant impact on surgical healing with the use of GTR when BPT is >1.0 mm. The GTR had a significant impact on surgical healing when the BPT was ≤1.0 mm.

CONCLUSIONS

This study supported the use of CBCT to evaluate three-dimensional healing after EMS. The Author2-Author1 index was found to be a clinically relevant method for assessing healing. To improve healing rate, the EMS cases with a preoperative BPT of ≤1.0 mm may benefit from GTR.

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.

Outcomes reporting in systematic reviews on surgical endodontics: A scoping review for the development of a core outcome set

BACKGROUND

Evidence-informed decision-making in healthcare relies on the translation of research results to everyday clinical practice. A fundamental requirement is that the validity of any healthcare intervention must be supported by the resultant favourable treatment outcome. Unfortunately, differences in study design and the outcome measures evaluated often make it challenging to synthesise the available research evidence required for secondary research analysis and guideline development. Core outcome sets (COS) are defined as an agreed standardised set of outcomes which should be measured and reported as a minimum in all clinical trials on a specific topic. The benefits of COS include less heterogeneity, a reduction in the risk of reporting bias, ensuring all trials contribute data to facilitate meta-analyses, and given the engagement of key stakeholders, it also increases the chances that clinically-relevant outcomes are identified. The recognition of the need for COS for assessing endodontic treatment outcomes lead to the development of Core Outcome Sets for Endodontic Treatment modalities (COSET) protocol, which is registered (No. 1879) on the Core Outcome Measures in Effectiveness Trials (COMET) website.

OBJECTIVES

The objectives of this scoping review are to: (1) identify the outcomes assessed in studies evaluating surgical endodontic procedures; (2) report on the method of assessment used to measure the outcomes; (3) and assess selective reporting bias in the included studies. The data obtained will be used to inform the development of COS for surgical endodontics.

METHODS

A structured literature search of electronic databases and the grey literature was conducted to identify systematic reviews on periradicular surgery (PS), intentional replantation (IR) and tooth/root resection (RR), published between January 1990 and December 2020. Two independent reviewers were involved in the literature selection, data extraction and the appraisal of the studies identified. The type of intervention, outcomes measured, type of outcomes reported (clinician- or patient-reported), outcome measurement method, and follow-up period, were recorded using a standardised form.

RESULTS

Twenty-six systematic reviews consisting of 19 studies for PS, three studies for IR and four studies for RR were selected for inclusion. Outcome measures identified for PS and IR included pain, swelling, mobility and tenderness, outcomes related to periodontal/soft tissue healing (including sinus tract), periradicular healing, tooth survival, life impact (including Oral-Health-Related-Quality-of-Life), resource use and/or adverse effects. For RR, in addition to tooth survival, endodontic complications, and adverse effects, the outcome measures were primarily periodontal-related, including pocket depth reduction, attachment gain, periodontal disease, and periodontic-endodontic lesions. The majority of outcome measures for PS, IR, and RR were assessed clinically, radiologically and/or via patient history. Specific tools such as rating scales (Visual Analog Scale, Verbal rating Scale, Numerical Rating Scale, and other scales) were used for the assessment of pain, swelling, and tenderness, and validated questionnaires were used for the assessment of oral health-related quality of life. The range of follow-up periods were variable, dependent on the outcome measure and the type of intervention.

CONCLUSIONS

Outcome measures, method of assessment and follow-up periods for PS, IR and RR were identified and categorised to help standardise the reporting of outcomes for future research studies. Additional outcome measures that were not reported, but may be considered in the COSET consensus process include loss of root-end filling material, number of clinic visits, surgery-related dental anxiety and muco-gingival aesthetic-related measures, such as scarring, black triangles, root surface exposure, and tissue discolouration.

Sealing ability of two root-end filling materials at different retro-preparation lengths

PURPOSE

The aim of the present study was to evaluate the sealing performance, expressed as microleakage (ML), of two root-end filling materials when used at different retro-preparation lengths.

METHODS

Fifty single-rooted human teeth were collected for the study. The teeth were cut at the cement-enamel junction and endodontic treatment was performed. Each root was cut at 3 mm from the apex and then stored in wet condition. The teeth were divided into three groups according to the retro-preparation length: control group (no retro-preparation); group 1 (retro-preparation of 3 mm); group 2 (retro-preparation of 9 mm). The teeth were equally allocated to either Biodentine or Super EBA treatment group. The teeth were immersed in 3% methylene blue dye solution for 24 h. The samples were split longitudinally and the depth of dye penetration was examined through light microscopy.

RESULTS

No significant statistical differences were found at different retro-preparation lengths (P > 0.05). Differences were found between materials (P > 0.05).

CONCLUSION

Biodentine showed significantly lower ML when compared to Super-EBA and no statistical significative differences were observed when samples were retro-prepared at 3 mm or 9 mm.

Impact of Periodontal Attachment Loss on the Outcome of Endodontic Microsurgery: A Systematic Review and Meta-Analysis

Background and Objectives: Endodontic microsurgery (EMS) aims to eradicate the sources of infection once the apical root resection removes most of the infected anatomical structures and repairs potential procedural errors in the apical region. An endodontic-periodontal lesion yields a pathological communication between the pulp and the periodontium. The purpose of this systematic review and meta-analysis is to evaluate the impact of periodontal attachment loss on the outcome of teeth submitted to EMS. Materials and Methods: PRISMA guidelines were followed. An electronic search was performed in EBSCOhost, Embase and PubMed databases with the following search key: (“endodontic microsurgery” AND “outcome”). No filters were used concerning the year of publication or language. Only randomized clinical trials, prospective and retrospective clinical studies in humans, with a minimum one-year follow-up, defined clinical and radiographic outcome criteria and estimable success rate for endodontic-periodontal lesion were included. Statistical analysis was performed using OpenMeta[Analyst] software. Results: Of a total of 113 articles, 34 were selected for full-text reading after duplicates deletion and title and abstract analysis. Thirteen and six studies were included in the systematic review and meta-analysis, respectively. A total of 2775 pooled teeth were submitted to EMS, of which 492 teeth and 4 roots had periodontal involvement. According to the qualitative analysis, success rates of the endodontic-periodontal group ranged from 67.6% to 88.2%. Meta-analysis revealed that the absence of periodontal attachment loss was predictive of a higher likelihood of success with an odds ratio of 3.14. Conclusions: Periodontal attachment loss presents a risk factor for EMS outcome. Although endodontic-periodontal lesions were associated with lower success rates considering a 1 to 10 years follow-up period, long-term successful prognosis following EMS has been reported, therefore presenting a fully valid and viable therapeutic option for the management of this type of lesions.

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

INTRODUCTION

A 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.

METHODS

This 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.

RESULTS

A 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.

CONCLUSIONS

The 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.

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.

Accuracy of root-end resection using a digital guide in endodontic surgery: An in vitro study

Background/Purpose

It is difficult to achieve accurate root-end resection clinically. This in vitro study was conducted to evaluate the operation accuracy of a digital endodontic surgical guide.

Materials and methods

56 extracted maxillary anterior teeth were prepared for endodontic surgical models. The models were randomly divided into 4 groups equally according to the guide (with guide/no guide) and the operator (experienced/inexperienced). Endodontic microsurgeries were performed on models in each group. The deviations in length and angle of the root-end resection were measured based on the optical scanning data of the pre- and postoperative teeth. The general linear model was performed to analyze the effect of a guide on root-end resection deviation.

Results

Using a guide, the mean length deviation for experienced/inexperienced operators reduced from 0.99 mm (95% CI [confidence interval, CI], 0.66–1.33 mm)/1.18 mm (95% CI, 0.50–1.86 mm) to 0.31 mm (95% CI, 0.20–0.42 mm)/0.31 mm (95% CI, 0.24–0.37 mm). The mean angle deviation for experienced/inexperienced operators reduced from 16.74° (95% CI, 10.61–22.86°)/15.06° (95% CI, 9.19–20.94°) to 5.04° (95% CI, 3.31–6.77°)/6.79° (95% CI, 4.91–8.67°). The difference was significant between procedures performed with and without a guide (P < 0.01).

Conclusion

Application of the digital guide in vitro endodontic surgery could improve the accuracy of root-end resection.

Prognostic Factors of Long-Term Outcomes in Endodontic Microsurgery: A Retrospective Cohort Study over Five Years

The aim of this study was to analyze the long-term outcomes of endodontic microsurgeries in a cohort and identify their association with prognostic factors. A cohort of endodontic microsurgeries followed up periodically with complete clinical and radiographic records for at least 5 years were reviewed retrospectively. Their survival and healing status and profile characteristics were analyzed by Pearson chi-square test and logistic regression (α = 0.05) to identify prognostic factors that influenced outcomes. Of 652 cases in the cohort, 225 (34.5%) were included. The mean follow-up period was 90.4 months (range, 60–168 months). The long-term success rate was 80.5%, and the 5-year survival rate was 83.5%. Logistic regression showed higher success in anteriors compared to molars (OR = 5.405, (95% CI, 1.663–17.571; p = 0.005)) and in teeth with crown restorations (OR = 10.232, (95% CI, 3.374–31.024; p < 0.001)). Conversely, lower success was found in teeth with periodontal disease (OR = 0.170, (95% CI, 0.032–0.900; p = 0.037)) and maxillary sinus involvement (OR = 0.187, (95% CI, 0.035–0.994; p = 0.049)). Endodontic microsurgery has a highly favorable long-term outcome. Tooth position, crown restoration, periodontal disease, and maxillary sinus involvement were identified as main prognostic factors.

Root-end microsurgery using a premixed tricalcium silicate putty as root-end filling material: a prospective study

OBJECTIVES

The purpose of this study was to assess the clinical and radiographic outcome of root-end microsurgery using a premixed fast-set calcium silicate putty as root-end filling material in human teeth.

MATERIALS AND METHODS

This study included 50 teeth in 35 patients, whose ages ranged from 16 to 69 years. After clinical and radiographic examination, informed consent was obtained and one resident performed all surgical procedures using an endodontic microsurgical approach. A tricalcium silicate-based putty (TotalFil FS putty, FKG Dentair, La Chaux-de-Fonds, Switzerland) was used as a root-end filling material. Patients were recalled and treated teeth were examined clinically and radiographically at 3 months, 6 months, and 1 year postoperatively. The outcome was determined based on clinical and radiographic results. Radiographic healing was classified into 4 categories: complete, incomplete, uncertain, and unsatisfactory. Analysis of predictors was performed using the Pearson chi-square or Fisher's exact test.

RESULTS

At the time of surgery, 3 teeth were diagnosed with cracks and were excluded from the study. The recall rates were 85% at 3 months, 100% at 6 months, and 95% at 1 year. One tooth failed at 3 months, 3 failed at 1 year, with a success rate of 93%. None of the predictors investigated had a significant influence on the outcome of microsurgery.

CONCLUSIONS

Premixed fast-set tricalcium silicate putty is a suitable root-end filling material for use in endodontic microsurgery.

CLINICAL RELEVANCE

Tricalcium silicate-based cements have shown promising biological properties as a root-end-filling material. Premixed and fast-set formulations achieved high success rates in clinical studies.

TRIAL REGISTRATION

Clinicaltrials.gov registration number NCT03733938.

Healing of Periapical Lesions After Surgical Endodontic Retreatment: A Systematic Review

Background: Surgical root canal retreatment is required when peri-radicular pathosis associated with endodontically treated teeth cannot be treated by non-surgical root canal therapy (retreatment), or when retreatment was ineffective, not feasible or contraindicated. Endodontic failures maybe happen when irritants remain within the confines of the root canal, or when an extra-radicular infection cannot be eradicated by orthograde root canal treatment. Following enhanced microsurgical techniques in the last years, the success rates of surgical root canal retreatment have improved considerably.

Objective: The aim of this systematic review is to gather updated data in regard to the surgical root canal (retrograde) retreatment to heal the periapical lesions.

Materials and methods: The electronic databases PubMed and Google Scholar were searched in this review using specific inclusion and exclusion criteria. The search was performed in June 2019 and updated in November 2019. Among 3900 studies, 10 studies satisfied the eligibility criteria and were included in the review to be analyzed.

Results: The 10 studies showed the importance of surgical root canal retreatment as a treatment option in removing infections within the root canal system and its efficiency in periapical tissue healing. These studies investigated different aspects of healing of periapical lesion after surgical (retrograde) retreatment including success rates, follow-up duration, and updated studies in surgical (retrograde) retreatment.

Conclusions: Surgical root canal (retrograde) retreatment demonstrates its efficiency in reducing the period needed for healing of the periapical lesions in short-term follow-up compared to conventional orthograde retreatment.

Factors influencing the long-term prognosis of root tip resected teeth

Introduction: The aim of the study was to investigate possible predictive factors influencing the long-term success of root tip resection. Methods: The retrospective study included 216 patients (♂ 111, ♀ 106, median age 43.3 years). A total of 261 root tip resections were performed on these patients between 1989 and 2012. In addition to determining the success rates 5 and 10 years postoperatively, the factors gender, age, tooth type, use of bone replacement material and preoperative periodontal tooth status were examined with regard to their significance for the long-term prognosis of root tip resected teeth. Results: The evaluation showed an average success rate of 63.6% for all included teeth over the entire observation period (tooth at least one year postoperatively still in situ). The 5-year success rate was 78.2%, the 10-year success rate 63.1%. A dependence of the success rates on the tooth type could not be evaluated. However, the examination showed a clear dependence of the success on the age of the patients. Root tip resections in patients in the age group 60 years and older had significantly worse success rates compared to the age groups 20 to 39 years and 40 to 59 years. The prognosis was also significantly better for patients in the age group 20 to 39 years than for patients in the age group 40 to 59 years. Periodontally compromised teeth showed only a tendency for a poorer prognosis than periodontally healthy teeth. With regard to sex and intraoperative filling of the resection defect with bone replacement material, no differences in the success rates were found. Conclusions: A root tip resection is a good option, largely independent of the type of tooth, to preserve a tooth in the medium to long term after unsuccessful endodontic treatment. However, a revision of the endodontic treatment or even an extraction with subsequent implantation should always be considered as an alternative, especially with increasing age.

Detection of Simulated Periradicular Lesions in Porcine Bone by Optical Coherence Tomography

INTRODUCTION

The accurate detection of periradicular lesions located under a nonperforated cortical plate poses a challenge in endodontic microsurgery. Optical coherence tomography (OCT) is a noninvasive imaging method that has been successfully used in many dental applications. In this study, we investigated if spectral-domain OCT (SD-OCT) could be used to determine simulated periradicular lesions.

METHODS

Twenty-eight cavities with different depths were prepared on bone plates obtained from 5 porcine mandibles. Both 3-dimensional SD-OCT imaging and micro-computed tomographic (micro-CT) imaging were used to image the bottom of the air-filled cavity and the cavity filled with soft tissue for comparison. The residual bone thickness under the cavity was measured by SD-OCT and micro-CT imaging and compared using the Pearson correlation.

RESULTS

The air-filled lesions were readily detected; yet, filling of the cavity with soft tissue diminished the appearance of the lesion boundaries in the SD-OCT images. The optical values of residual bone thickness obtained from SD-OCT ranged from 0.14-2.11 mm, which corresponded to the range of 0.26-1.18 mm from micro-CT imaging. A strong correlation was found between the 2 imaging modalities (r = 0.96; range, 0.94-0.98). The slope (1.56) of the linear regression matched the bulk refractive index of bone tissues.

CONCLUSIONS

SD-OCT allows for visualization of the lesion boundaries via intact bone surfaces and may be a promising, practical, and nonirradiating adjunct tool for chairside localization of periradicular lesions in bone.

Quorum sensing LuxS/autoinducer-2 inhibits Enterococcus faecalis biofilm formation ability

OBJECTIVE

To investigate the relation between biofilm formation ability and quorum sensing gene LuxS/AI-2.

MATERIALS AND METHODS

Enterococcus faecalis (E. faecalis) standard strain ATCC 29212 was used in the study. Long flanking homology polymerase chain reaction method was used to build the LuxS gene knockout strain. Sequential culture turbidity measurement and CFU counting were used to assess the proliferation ability of E. faecalis after the depletion of LuxS. 96-well plate assay was used to quantify the biofilm formation ability; CLSM was used to observe the attached bacteria areas, while scanning electron microscopy (SEM) was performed to observe biofilm microstructure conditions.

RESULTS

LuxS gene knockout strains were successfully constructed and identified. The results showed that proliferation ability of E. faecalis was not affected by the depletion of the luxS gene, and the biofilm formation ability of ΔLuxS 29212 significantly decreased (P<0.05).

CONCLUSIONS

Collectively, our studies provide the LuxS gene's key role in controlling biofilm formation of E. faecalis, which presented a negative regulation, and furthermore, providing us a possible way to conquer the persistent apical periodontitis.

Outcome of Endodontic Surgery: A Meta-analysis of the Literature-Part 3: Comparison of Endodontic Microsurgical Techniques with 2 Different Root-end Filling Materials

INTRODUCTION

The aim of the present study was to investigate the influence of root-end preparation and filling material on endodontic surgery outcome. A systematic review and meta-analysis was conducted to determine the outcome of resin-based endodontic surgery (RES, the use of high-magnification preparation of a shallow and concave root-end cavity and bonded resin-based root-end filling material) versus endodontic microsurgery (EMS, the use of high-magnification ultrasonic root-end preparation and root-end filling with SuperEBA [Keystone Industries, Gibbstown, NJ], IRM [Dentsply Sirona, York, PA], mineral trioxide aggregate [MTA], or other calcium silicate cements).

METHODS

An exhaustive literature search was conducted to identify prognostic studies on the outcome of root-end surgery. Human studies conducted from 1966 to the end of December 2016 in 5 different languages (ie, English, French, German, Italian, and Spanish) were searched in 4 electronic databases (ie, Medline, Embase, PubMed, and Cochrane Library). Relevant review articles on the subject were scrutinized for cross-references. In addition, 5 dental and medical journals (Journal of Endodontics; International Endodontic Journal; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics; Journal of Oral and Maxillofacial Surgery; and International Journal of Oral and Maxillofacial Surgery) were hand checked dating back to 1975. All abstracts were screened by 3 independent reviewers (H.B., M.K., and F.S.). Strict inclusion-exclusion criteria were defined to identify relevant articles. Raw data were extracted from the full-text review of these selected articles independently by each of the 3 reviewers. In case of disagreement, an agreement was reached by discussion, and qualifying articles were assigned to group RES. For EMS, the same search strategy was performed for the time frame October 2009 to December 2016, whereas up to October 2009 the data were obtained from a previous systematic review with identical criteria and search strategy. Weighted pooled success rates and a relative risk assessment between RES and EMS were calculated. To make a comparison between groups, a random effects model was used.

RESULTS

Sixty-eight articles were eligible for full-text review. Of these, per strict inclusion exclusion criteria, 14 studies qualified, 3 for RES (n = 862) and 11 for EMS (n = 915). Weighted pooled success rates for RES were 82.20% (95% confidence interval [CI], 0.7965-0.8476) and 94.42% for EMS (95% CI, 0.9295-0.9590). This difference was statistically significant (P < .0005).

CONCLUSIONS

The probability for success for EMS proved to be significantly greater than the probability for success for RES, providing best available evidence on the influence of cavity preparation with ultrasonic tips and/or SuperEBA (Keystone Industries, Gibbstown, NJ), IRM (Dentsply Sirona, York, PA), MTA, or silicate cements as root-end filling material instead of a shallow cavity preparation and placement of a resin-based material. Additional large-scale randomized clinical trials are needed to assess other predictors of outcome.

An Insight into Histopathologic Examination as a Gold Standard for the Diagnosis of Chronic Apical Periodontitis

Objective: The purpose of our study was to determine the level of correlation between histopathologic results after surgery for chronic apical periodontitis and the radiographic and clinical diagnosis. The status of gold standard technique of histologic examination was evaluated in the diagnosis of apical radiolucency in necrotic teeth.

Methods: Out of 154 patients with incorrect root fillings and apical radiolucency included in an endodontic retreatment protocol, 87 patients (108 teeth) were scheduled for apical surgery at 3-6 months control recall. Clinical and radiographic exams were completed prior to surgery and compared to the histological results of apical biopsies. The collected data were statistically analyzed with the SPSS version 20.0 and the Chi-square test was used to determine the associations between clinical and histologic diagnosis. A value of p <0.05 was considered statistically significant.

Results: There was a statistically significant difference between the number of cases diagnosed as granulomas or cysts during clinical and radiological evaluation compared to histologic evaluation of tissue samples, with 40.9% to 75.9% and 54.2% to 16.8% respectively (p<0.05).

Conclusions: The final diagnosis was obtained only after histologic examination of apical tissue samples, which means that the observations made based on radiologic investigations must be confirmed by biopsy.

Comparison of the effect of endodontic-periodontal combined lesion on the outcome of endodontic microsurgery with that of isolated endodontic lesion: survival analysis using propensity score analysis

OBJECTIVES

The purpose of this retrospective clinical study was to evaluate the effect of lesion types related to endodontic microsurgery on the clinical outcome.

MATERIALS AND METHODS

Patients who underwent endodontic microsurgery between March 2001 and March 2014 with a postoperative follow-up period of at least 1 year were included in the study. Survival analyses were conducted to compare the clinical outcomes between isolated endodontic lesion group (endo group) and endodontic-periodontal combined lesion group (endo-perio group) and to evaluate other clinical variables. To reduce the effect of selection bias in this study, the estimated propensity scores were used to match the cases of the endo group with those of the endo-perio group.

RESULTS

Among the 414 eligible cases, the 83 cases in the endo-perio group were matched to 166 out of the 331 cases in the endo group based on propensity score matching (PSM). The cumulated success rates of the endo and endo-perio groups were 87.3 and 72.3%, respectively. The median success period of the endo-perio group was 12 years (95% CI: 5.507, 18.498). Lesion type was found to be significant according to both Log-rank test (P = 0.002) and Cox proportional hazard regression analysis (P = 0.001). Among the other clinical variables, sex (female or male), age, and tooth type (anterior, premolar, or molar) were determined to be significant in Cox regression analysis (P < 0.05).

CONCLUSION

Endodontic-periodontal combined lesions had a negative effect on the clinical outcome based on an analysis that utilized PSM, a useful statistical matching method for observational studies.

CLINICAL RELEVANCE

Lesion type is a significant predictor of the outcome of endodontic microsurgery.

Hyaluronan induces odontoblastic differentiation of dental pulp stem cells via CD44

Background

Dental pulp tissue contains many undifferentiated mesenchymal cells, which retain the ability to differentiate into mature cells. Induced pluripotent stem cells have been developed from various cell sources, including dental pulp-derived stem cells, and evaluated for potential application to regenerative therapy. Dental pulp tissues overexpress CD44, a cell-adhesion factor involved in the induction of mineralization. In this study, we investigated the effects of hyaluronan—a known CD44 ligand—on dental pulp stem cells (DPSCs).

Methods

DPSC CD44 expression was analyzed using immunofluorescence staining, flow cytometry, and western blotting. Cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Effects of hyaluronan on the cell cycle were analyzed by flow cytometry. Alkaline phosphatase activity was employed as marker of mineralization and measured by fluorometric quantification and western blotting. Bone morphogenetic protein (BMP)-2, BMP-4, dentin sialophosphoprotein (DSPP), and dentin matrix acidic phosphoprotein 1 (DMP-1) levels were measured using real-time polymerase chain reaction. Odontoblastic differentiation and the close cell signaling examination of DPSC differentiation were determined using western blotting.

Results

Hyaluronan induced expression of the odontoblastic differentiation markers DMP-1 and DSPP. Moreover, the odontoblastic differentiation induced by hyaluronan was mediated by CD44—but not by Akt, Smad1 or MAPK signaling.

Conclusions

Our results indicate that hyaluronan induces odontoblastic differentiation of DPSCs via CD44. This suggests that hyaluronan plays a crucial role in the induction of odontoblastic differentiation from DPSCs. Our findings may aid the development of new, inexpensive, and effective conservative treatments for dental pulp repair.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0399-8) contains supplementary material, which is available to authorized users.

Scanning electron microscopy reveals severe external root resorption in the large periapical lesion

The present study was designed to investigate the relationships between clinicopathological findings and the resorptive conditions of root apices of teeth with periodontitis. The samples included 21 root apices with large periapical radiolucent lesions. The preoperative computed tomography (CT) and intraoperative findings were correlated with the presence, extension, and the progression pattern of periapical resorption using a scanning electron microscope. The subjects' age, gender, chief complaint, type of tooth, percussion test results, size of periapical lesion using CT, and intraoperative findings were recorded. All apicoectomies were performed under an operative microscope for endodontic microsurgery. A significant large size was observed in cystic lesions compared with granulomatous lesions. The cementum surface at the periphery of the lesion was covered with globular structures (2-3 μm in diameter). Cementum resorption started as small defect formations at the surface. As the defect formation progressed, a lamellar structure appeared at the resorption area, and the size of globular structures became smaller than that of globules at the surface. Further resorption produced typical lacuna formation, which was particularly observed in fracture cases. The most morphologically severe destructive pattern of dentin resorption was observed in large cystic lesions. This study is the first report to elucidate the relationships between three clinical types of undesirable periapical lesions: (1) undertreatment, (2) periapical fracture, (3) macro-level resorption, and the microstructure of external root resorption including from small defects at the cementum surface to a significant destructive pattern inside the dentin. Microsc. Res. Tech. 79:495-500, 2016. © 2016 Wiley Periodicals, Inc.

A Survey over the Dentists' and Endodntists' Approaches towards the Management of Endodontic Emergencies in Mashhad, Iran

Introduction:

Pain or swelling caused by various stages of inflammation/infection of the pulp/periradicular area is among endodontic emergencies. Determining the most effective method of emergency treatment is a challenging issue in endodontics. The goal of this study was to determine and compare the level of knowledge in general dentists and endodontists about endodontic emergency treatment plan in Mashhad, Iran in 2012-2013.

Methods and Materials:

In this cross-sectional descriptive study, 152 questionnaires were distributed among 120 general dentists and 32 endodontists of Mashhad. The questionnaire contained two separate parts. The first part included demographic information and in the second part different treatment protocols were suggested for 12 various conditions of pulp/periapical emergencies, and the participants were asked to choose the correct option(s). To determine the relationship between qualitative variables, the chi-square analysis was used. The level of significance was set at 0.05.

Results:

There were significant differences between treatment plans presented by general dentists and endodontists about endodontic emergencies, especially in cases of necrotic pulp and subsequent swelling.

Conclusion:

Level of knowledge of dentists about the indications of incision and drainage, intra-canal medicament, root filing beyond the apical foramen and antibiotic prescription was not enough. These findings highlight the importance of refreshing courses for general dentists to improve their competency in the management of endodontic emergencies.

Agreement between 2D and 3D radiographic outcome assessment one year after periapical surgery

AIM

To compare 2D with 3D radiography in assessing the treatment outcome 1 year after periapical surgery.

METHODOLOGY

In this prospective study, periapical radiographs (PA) and cone beam computed tomography (CBCT) were performed 1 year after periapical surgery. Three calibrated observers independently evaluated the radiographs for the presence and type of periapical radiolucencies. Ratings in PA were compared to those in bucco-lingual and mesio-distal CBCT images (coronal and sagittal planes), and the ratings of the latter two were also compared between each other. Further, maximum size diameters of radiolucencies were measured on CBCT scans, and the calculated means were correlated with the types of radiolucency. Statistical analysis was completed using Friedman rank sum tests, the Wilcoxon signed rank test and the Pearson correlation coefficient.

RESULTS

A total of 61 roots in 54 patients were eligible for the final assessment. On average, the intra-observer ratings were identical in 59.6% when comparing PA and CBCT (kappa 0.112 to 0.192). A very high intra-observer agreement (93.4%) was noted when comparing bucco-lingual and mesio-distal CBCT ratings (kappa 0.797 to 1). Interobserver agreement was higher for PA (68.8%) than for CBCT (bucco-lingual 45.9%, mesio-distal 47.5%), but without reaching significant differences. The calculated mean size of persistent radiolucencies in CBCT scans correlated well with the assigned types of radiolucency.

CONCLUSION

CBCT images showed in nearly a third of the evaluated cases a worse situation than PA. There is a need to define criteria to assess the 'radiographic healing' in CBCT following periapical surgery.

Three-year outcomes of apicectomy (apicoectomy): Mining an insurance database

OBJECTIVES

The outcome of apicectomy in clinical reality is supposed to be different compared to outcomes reported from clinical trials. The objective of this study was to measure the outcome of apicectomies under practice conditions by mining an insurance data base.

METHODS

This retrospective study was based on claims data of a major German national health insurance company (BARMER GEK). Through the company's data warehouse fee codes and treatment dates were accessible and allowed the tracing of clinical courses. Kaplan-Meier survival analyses for the target event 'extraction' were conducted for all teeth that underwent apicectomies within a 3 year period. Testing for differences among survival rates across groups was performed with the Log-Rank-test.

RESULTS

A total of 93,797 teeth in 77,636 patients could be traced after apicectomy. The cumulative 3-year survival rate was 81.6%. Anterior teeth showed a significantly higher survival rate of 84.0% compared to premolars (80.4%) and molars (80.2%). The survival rate in men (83.5%) was significantly higher than in women (80.6%). Analysis of survival by age revealed continuously declining survival rates with age (93.3% for subjects under 18 years of age to 75.6% for subjects over 84 years of age).

CONCLUSIONS

The 3-year outcomes of apicectomy were still acceptable for an intervention that is mostly conducted as a retreatment after failure of a preceding measure. However at a population level, the question remains to be answered whether other treatment options would potentially be more effective.

The outcome of apical microsurgery using MTA as the root-end filling material: 2- to 6-year follow-up study

AIM

To evaluate the influence of various predictors on the healing outcome 2-6 years after apical microsurgery (AMS) using MTA as the root-end filling material.

METHODOLOGY

A total of 90 anterior teeth with asymptomatic persistent periradicular periodontitis of strictly endodontic origin that failed after either nonsurgical or surgical treatment were included. Surgery was completed under local anaesthesia using a standardized clinical protocol. Clinical and radiographic measures as well as the follow-up period were used to determine the healing outcome. For statistical analysis of the predictors, the outcome was dichotomized into healed cases and nonhealed cases. Odds ratios were calculated, and Pearson chi-square or Fisher's exact tests were used to analyse the data.

RESULTS

Clinical and radiographic assessment of AMS revealed that 80% were healed, 14.4% were nonhealed, whilst 5.6% were judged to be uncertain. None of the various predictors investigated had a significant influence on the outcome of AMS.

CONCLUSIONS

The results of this clinical study demonstrated that 80% of cases that received apical microsurgery healed when using MTA as the root-end filling material.

Endodontic-periodontal microsurgery for combined endodontic-periodontal lesions: An overview

Endodontic and periodontal microsurgery has surpassed the success rates for traditional endodontic and periodontal surgical procedures. Excellent healing results are being attributed to both the techniques, when employed, for isolated endodontic or periodontal defects. Combined endodontic-periodontal lesions have been referred to as a true challenge, requiring not only endodontic microsurgical management but also concurrent bone grafting and membrane barriers techniques. The prevention of epithelial downgrowth and regeneration of periodontal cementum, fiber, and bone seals the fate of these cases. Achieving primary closure with submergence of grafts has a positive effect on GTR outcome. New techniques of periodontal microsurgery, such as minimally invasive papilla preserving flaps with passive internal mattress suturing, have managed to obtain 90% primary flap closure over grafted sites. Root surface treatment and conditioning has also shown to be beneficial for GTR. Endodontic microsurgery for the combined lesion has not integrated these advances yet. These advances, along with a recently suggested treatment strategy, are ushering in the level next in management of the combined lesions. This article offers an overview of the combined lesion, the disease, its classification, treatment strategy, regenerative tools, microsurgical recommendations, and outcome studies.

Guided tissue regeneration in endodontic surgery by using a bioactive resorbable membrane

INTRODUCTION

Guided tissue regeneration is a valuable technique available to the endodontist because the quality, quantity, or extent of bone loss cannot be visualized by the surgeon until the tissue is reflected and the surgical site is exposed.

METHODS

After repeated attempts at nonsurgical treatment, a patient with a recurring sinus tract over the distobuccal root of an upper molar ultimately had the distobuccal root resected, leaving a 10 × 10 mm bony defect. This dehiscence was filled with freeze-dried bone and covered with a flexible and absorbable bioactive membrane that was new to endodontics.

RESULTS

Healing was uneventful, and bone regeneration was rapid and extensive as observed at the time of a second surgery just 5 months later. This can be attributed at least in part to the use of the bioactive membrane that contains an array of growth factors that enhance cell proliferation, inflammation, recruitment of progenitor cells, and metalloproteinase activity.

CONCLUSIONS

The use of the bioactive membrane in endodontic surgery should be considered to best restore the attachment apparatus to the tooth and prevent the downgrowth of a long junctional epithelium. The endodontist's attention must not be limited to the apical region alone.

Nonsurgical management of an extensive endodontic lesion in an orthodontic patient by calcium-enriched mixture apical plug

Periapical lesion is a general term used to describe the periapical inflammatory process that occurs in response to the invasion of micro-organisms in the root canal system as well as inflamed vital pulp. This phenomenon necessitates endodontic intervention and if the necrosis has occurred prior to tooth maturation, wide patency of the apical foramen requires some treatment modalities such as apexification or apical plug. Orthodontic treatment, on the other hand, is cautiously done for previously traumatized teeth due to increased risk for necrosis of the compromised tooth. This article tends to review the successful treatment process with calcium-enriched mixture (CEM) cement apical plug for an immature previously traumatized incisor tooth with an extensive periapical lesion, which was under orthodontic treatment as well.