Outcome of nonsurgical retreatment and endodontic microsurgery: a meta-analysis

Evaluation of a Novel Drilling Approach for Dynamic Navigation-Aided Endodontic Microsurgery: A Surgical Simulation Comparison Study

INTRODUCTION

This study investigated the feasibility of a novel drilling approach that integrates a pilot trephine into dynamic navigation (DN) for guided osteotomy and root-end resection (RER) with unimanual operation in endodontic microsurgery.

METHODS

Two operators with varying levels of DN experience performed guided osteotomy and RER using 2 unimanual drilling methods with DN-aided operation on 3-dimensional printed jaw models. Method 1 (M1) involved drilling with a conventional trephine. Method 2 (M2) involved drilling with a pilot trephine, followed by drilling with a conventional trephine. Accuracy, time, and safety of M1 and M2 were compared. Accuracy measurements included platform deviation (PD), end deviation (ED), angular deviation (AD), resection length deviation (RLD), and resection bevel angle (RBA). Additional parameters included osteotomy and RER time (OT) and bur slippage number (BSN). Statistical analyses were conducted using a 2-sample t-test or Mann-Whitney U test, with the significance level set at .05.

RESULTS

The PD, AD, RBA, and BSN in the M2 group were significantly less than in the M1 group (P < .05). For M1, the novice operator (NO) exhibited significantly higher values of PD, ED, OT, and BSN than the experienced operator (EO) (P < .05). For M2, the NO exhibited significantly higher value of ED only (P < .05), and drilling depth >7 mm was significantly associated with a longer OT (P < .05).

CONCLUSION

In this surgical simulation comparison study, the incorporation of a pilot drill improved the accuracy and safety of DN-aided endodontic microsurgery.

Outcome of root canal retreatment filled with gutta-percha techniques: A systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis aimed to evaluate the success rate of root canal retreatment filled with gutta-percha and the variables related to retreatment success.

DATA

The PRISMA guidelines were followed for the present review. The study protocol was registered in the International Prospective Database of Systematic Reviews (PROSPERO CRD42021283134). Risk assessment was performed using the Newcastle-Ottawa scale. Funnel plots were used to detect publication bias and asymmetry was assessed using Egger's tests.

SOURCES

PubMed, Scopus, ScienceDirect, Cochrane, and additional sources were searched.

STUDY SELECTION

Studies published until 10 December 2022. Clinical studies evaluating the success of root canal retreatment filled with gutta-percha with at least a 1-year follow-up were selected.

RESULTS

Ten studies and one unpublished study fulfilled the inclusion criteria for quantitative analysis. The success rate of non-surgical root canal retreatment was 71% (95% CI: 66%-76%) with strict criteria and 87% (79% - 93%) with loose criteria for 1-3 years of follow-up, and 77% (66% - 86%) with strict criteria for a 4-5 years of follow-up. Endodontically retreated teeth with periapical lesions had a lower success rate under strict criteria. The tooth type, dental arch, initial periapical index (PAI) score, and the number of visits also affected the treatment success rate under strict criteria. For the loose criteria, teeth with larger periapical lesions and higher initial PAI scores had a lower success rate.

CONCLUSIONS

According to the present systematic review and meta-analysis, non-surgical root canal retreatment results in favourable outcomes. The presence of a periapical radiolucency, periapical lesions >5mm, a higher initial PAI score, multiple-visit retreatments, and mandibular and molar teeth resulted in a lower success rate.

CLINICAL SIGNIFICANCE

Non-surgical root canal retreatment filled with gutta-percha techniques is a relatively predictable procedure with a high success rate. Several variables can affect retreatment success, mainly the presence and size of a periapical lesion and the type of tooth.

Risk factors associated with the survival of endodontically treated teeth: A retrospective chart review

BACKGROUND

Studies on risk factors affecting tooth retention after endodontic treatment in dental school settings are limited. Understanding these factors is crucial for preserving teeth. The aim of this retrospective study was to evaluate patient- and tooth-level risk factors associated with the survival of endodontically treated teeth.

METHODS

Electronic health records of patients who underwent endodontic treatment at the School of Dental Medicine at the University of Pennsylvania from 2017 through 2020 were analyzed. Patient-level factors included age, sex, American Society of Anesthesiologists Physical Status Classification, smoking history, diabetes status, and amoxicillin allergy. Tooth-level factors included position, presence of restorations, and periodontal conditions with preprosthetic treatments.

RESULTS

The results of this study indicate that the patient-level factors significantly associated with tooth retention included age, sex, American Society of Anesthesiologists Physical Classification Status, and amoxicillin allergy. Tooth-level factors such as core buildup, full-coverage crown, healthy periodontium, and scaling and root planing were also associated with higher survival rates. Mandibular premolars had higher survival rates than mandibular molars.

CONCLUSIONS

This investigation revealed that the tooth retention rate of endodontically treated teeth was 96.2% after initial root canal treatment, 92.4% for nonsurgical re-treatment, and 97.8% for surgical re-treatment.

PRACTICAL IMPLICATIONS

The tooth retention of the endodontic treatment was associated with healthy periodontium, tooth structure, tooth position, tooth restoration, and the patient's overall health.

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.

Clinical Outcome and Predictors of Endodontic Microsurgery Using Cone-beam Computed Tomography: A Retrospective Cohort Study

INTRODUCTION

The aim of this retrospective cohort study was to evaluate the clinical outcomes and identify the prognostic factors of endodontic microsurgery based on cone-beam computed tomographic (CBCT) scans.

METHODS

Patients who underwent endodontic microsurgery in teeth with asymptomatic apical periodontitis were included. The clinical outcomes were determined based on clinical and radiographic examinations after surgery 12-48 months. Radiographic healing was assessed on CBCT images by using the modified PENN 3-dimensional criteria and classified into 4 categories: complete, limited, uncertain, and unsatisfactory healing. Multivariate logistic regression was performed to detect outcome risk factors.

RESULTS

Of the 204 teeth in 173 invited patients, 148 teeth of 126 patients were examined at review. On CBCT images, 88 teeth (59.5%) showed complete healing, and 42 (28.4%) teeth showed limited healing. All these 130 teeth were asymptomatic and achieved a clinical success rate of 87.8%. Uncertain healing was observed in 9 teeth, one of which was symptomatic. The remaining 9 teeth were unsatisfactory healing on CBCT scans, including 6 teeth with clinical symptoms and 3 free. Lesion type and root-end filling quality were significant outcome predictors (P < .05). The risk of treatment failure for teeth with combined endodontic-periodontal lesions was 8.6 times higher than that for teeth with isolated endodontic lesions. Adequate root-end filling quality improved the probability of success by 5.3 times.

CONCLUSIONS

Based on CBCT data, an adequate performed endodontic microsurgery could have predictable success in teeth without periodontal involvement.

Treatment-Related Factors Affecting the Success of Endodontic Microsurgery and the Influence of GTR on Radiographic Healing-A Cone-Beam Computed Tomography Study

The primary objective of this retrospective study was to assess the correlation between treatment-related factors (resection angle, depth of retrograde filling, length of resected root and use of guided tissue regeneration-GTR) evaluated using cone-beam computed tomography (CBCT) scans and the treatment outcomes of endodontic microsurgery (EMS). The secondary purpose of this research was to evaluate the influence of the GTR technique on the radiographic healing state, taking into account the initial parameters of periapical lesions. In 161 cases, the local factors (volume of a lesion, bone destruction pattern, presence/absence of cortical bone destruction) were measured using preoperative CBCT images before undergoing EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure (based on radiographic and clinical criteria). Using postoperative CBCT, treatment-related factors (resection angle, depth of retrograde filling, and length of resected root) were measured. Additionally, the status of radiographic healing was evaluated (in accordance with modified PENN 3D criteria). Eighteen cases (11.18%) were classified as failures, and 143 were classified as successes (88.82%). Univariate analysis showed that there was no statistically significant influence of treatment-related factors on the healing outcome of EMS. An exact Fischer's test showed the significant impact of GTR on radiographic healing (P < 0.001) in apical lesions (P < 0.001), lesions with a volume between 100 mm3 and 450 mm3 (P < 0.009) and over 450 mm3 (P < 0.001), lesions with the destruction of one plate (P < 0.001), and lesions with the destruction of two plates (through and through) (P = 0.022). The use of GTR in apical lesions, lesions with volumes over 100 mm3, and lesions with the destruction of at least one plate is significantly associated with better radiographic healing.

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).

Outcomes reporting in systematic reviews on non-surgical root canal treatment: A scoping review for the development of a core outcome set

BACKGROUND

Studies related to non-surgical root canal treatment are amongst the most frequently performed clinical studies in endodontics. However, heterogeneity in reporting outcomes and lack of standardization is a significant challenge to evidence synthesis and guideline development.

OBJECTIVES

The aims of the present scoping review were to (a) identify outcomes reported in systematic reviews evaluating non-surgical root canal treatment; (b) identify how and when the reported outcomes were measured; (c) assess possible selective reporting bias in the included studies. The information obtained in this study should inform the development of a core outcome set (COS) for non-surgical root canal treatment.

METHODOLOGY

Structured literature searches were performed to identify systematic reviews on non-surgical root canal treatments published in English between January 1990 and December 2020. Two reviewers undertook study selection and data extraction. Outcomes were categorized according to a healthcare taxonomy into five core areas (survival, clinical/physiological changes, life impact, resource use, and adverse events). The outcome measurement tools and length of follow-up were recorded.

RESULTS

Seventy-five systematic reviews were included, of which 40 included meta-analyses. Most reviews reported on physiological and clinical outcomes, primarily pain and/or radiographic assessment of periapical status, and a variety of measurement tools and scales were used. Few reviews focused on tooth survival, life impact, resources, and adverse events. The heterogeneity amongst the reviews was large on all parameters. Less than 40% of the reviews assessed the risk of selective reporting.

DISCUSSION

Overall aims of the included reviews were highly heterogenic; thus, outcomes and how they were measured also varied considerably. Patient-centred outcomes and the use of resources were rarely reported on.

CONCLUSIONS

Most studies reported on physiological and clinical outcomes, in particular pain and/or radiographic healing. Measurement tools, scales, thresholds, and follow-up periods varied greatly within each outcome, making comparison across studies complicated. Less than 40% of the reviews assessed risk of selective reporting; thus, selective bias could not be ruled out. The presented information on reported outcomes, measurement tools and scales, and length of follow-up may guide the planning of future research and inform the development of a COS for non-surgical root canal treatment.

Dislodgement pushout resistance of five bioceramic root-end filling materials

This study evaluated the dislodgement push-out resistance of five bioceramic materials. One hundred single-rooted teeth with one canal had the apical 3 mm and crown resected to create a 14 mm standardized length. The canals were instrumented to an apical size 80 with a 3 mm root-end preparation made with ultrasonic diamonds. The prepared roots were randomly divided into 5 root-end restorative groups (n=20). ProRoot MTA, Biodentine, EndoSequence Root Repair Material, EndoSequence Fast Set Putty, and EndoSequence BC Sealer with each material placed following manufacturer's instructions and stored at 100% humidity for 2 weeks. An apical-to-coronal static testing load with the identified dislodgement force converted into MPa with mean results analyzed with Kruskal-Wallis and Dunn's post hoc tests (α=0.05). ProRoot MTA and Biodentine displayed similar push-out stress resistance and exhibited significantly greater stress resistance than the similar Endosequence materials. However, all materials failed cohesively and were not dislodged from the root canal surface.

Factors Affecting the Success of Endodontic Microsurgery: A Cone-Beam Computed Tomography Study

The purpose of this retrospective study was to verify preoperative local parameters of periapical lesions evaluated on cone-beam computed tomography (CBCT) scans as a potential prognostic factor in endodontic microsurgery (EMS). Among 89 cases, local factors (dimensions of lesion, bone destruction pattern, presence/absence of cortical bone destruction, height of buccal bone plate, apical extend of root canal filling, presence/absence of communication with anatomical cavities, type of lesion restriction) were measured on preoperative CBCT images before EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure. Ten cases (11.24%) were classified as a failure and 79 as a success (88.76%). Symptomatic lesions (OR = 0.088 (95% CI 0.011-0.731); p = 0.024), apicomarginal lesions (OR = 0.092 (0.021-0.402); p = 0.001) and an association with molar teeth (OR = 0.153 (0.032-0.732); p = 0.019) were found as negative predictive factors in the univariate analysis, whereas large apicocoronal dimension (OR = 0.664 (0.477-0.926); p = 0.016), apicomarginal lesions (OR = 0.058 (0.006-0.55); p = 0.013), and an association with molar teeth (OR = 0.047 (0.003-0.869); p = 0.04) were identified as negative predictive factors in the multivariate analysis model. Symptomatic lesions, apicomarginal lesions, lesions associated with molar teeth and large apicocoronal dimensions are significantly associated with the failure of EMS.

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.

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.

Leukocyte platelet-rich fibrin in endodontic microsurgery: a report of 2 cases

Endodontic microsurgery is a predictable treatment option when orthograde treatment or retreatment is unsuccessful or unfeasible. However, when there is a gross compromise of periapical bone, achievement of bone regeneration after the surgical procedure may be hampered. In such cases, the application of guided tissue regeneration principles, with adjunctive use of leukocyte platelet-rich fibrin to fill the bone defect as a bone substitute and as a membrane to cover the site, provides a cost-effective solution with the benefits of accelerated physiological healing and reduced post-surgical pain and discomfort. This case report presents 2 cases of endodontic microsurgery of the upper lateral incisors with loss of buccal cortical plate, where platelet-rich fibrin was successfully applied.

Effectiveness and safety of rotary and reciprocating kinematics for retreatment of curved root canals: a systematic review of in vitro studies

Objectives

This systematic review (register-osf.io/wg7ba) compared the efficacy and safety of rotary and reciprocating kinematics in the removal of filling material from curved root canals.

Materials and Methods

Only in vitro studies evaluating both kinematics during retreatment were included. A systematic search (PubMed/MEDLINE, Scopus, and other databases, until January 2021), data extraction, and risk of bias analysis (Joanna Briggs Institute checklist) were performed. Efficacy in filling removal was the primary outcome.

Results

The search resulted in 2,795 studies, of which 15 were included. Efficacy was measured in terms of the remaining filling material and the time required for this. Nine studies evaluated filling material removal, of which 7 found no significant differences between rotary and reciprocating kinematics. Regarding the time for filling removal, 5 studies showed no difference between both kinematics, 2 studies showed faster results with rotary systems, and other 2 showed the opposite. No significant differences were found in apical transportation, centering ability, instrument failure, dentin removed and extruded debris. A low risk of bias was observed.

Conclusions

This review suggests that the choice of rotary or reciprocating kinematics does not influence the efficacy of filling removal from curved root canals. Further studies are needed to compare the kinematics safety in curved root canals.

Outcome of single-visit- versus two-visit root canal retreatment in teeth with periapical lesions: a randomized clinical trial

AIM

To evaluate the clinical and radiographic outcome of single-visit root canal retreatment and to compare the results with conventional two-visit root canal retreatment as control group.

METHODOLOGY

One hundred root canal-treated, single-rooted asymptomatic teeth with periapical lesion were retreated by one operator. Fifty of the teeth were randomly assigned to the single-visit group and the others were treated in two-visits. In both groups, root canal filling material was removed, and re-instrumentation of the root canal was performed using step-back technique with hand files using 2.5% NaOCl and 5% EDTA as irrigants. In the single-visit group 5 ml 2% chlorhexidine (CHX) were applied as the final irrigation and in the two-visit group, calcium hydroxide paste was placed into the root canal as an interappointment dressing. All root canal obturations were performed with lateral compaction. All patients were followed up for 24 months. Success was determined depending on both healed and healing cases. The chi-square or Fisher's Exact test was used to analyse the differences between the groups for success rates and the factors affecting the outcome.

RESULTS

The recall rate was 89 (89%). At 24 months, 39 teeth (88.6%) were considered as healed, 3 teeth (6.8%) as healing, and 2 teeth (4.5%) were identified as failed in the single-visit group, while in the two-visit group 39 teeth (86.7%) had healed, 2 teeth (4.4%) were scored as healing, and 4 teeth (8.9%) as failed. There was no statistically significant difference in the success rates between the two groups (P > 0.05). Size of the lesion and the preoperative length of root canal filling had a statistically significant impact on the outcome (P < 0.05).

CONCLUSION

No statistically significant difference was observed in terms of healing in 24-month follow-up of retreatments completed in single-visit or two-visits in asymptomatic teeth with periapical lesions. Size of the periapical lesion and initial apical level of root canal filling have affected the outcome of root canal retreatment.

Psycho-social perspectives of nonsurgical versus surgical endodontic interventions in persistent endodontic disease

INTRODUCTION

Patients' experiences related to dental treatment could influence care-seeking behaviour and engender personal bias. Although endodontic retreatment and apical surgery are procedures often performed to manage previously treated teeth with persistent disease, there is lack of information regarding psycho-social perspectives of patients who undergo these treatments. Our aim was to compare experiences of patients who received these two treatment modalities using a qualitative approach.

METHODS

A purposive sample of patients was taken from our previous study utilizing the Oral Health Impact Profile to compare oral health-related quality of life of 150 patients who received retreatment and apical surgery. Patients who reported impact and no impact were invited to participate in focus group discussions (FGDs). Eighteen patients from the retreatment group and 15 patients from the surgical group participated in six FGDs. Thematic analysis was conducted to identify key themes.

RESULTS

Four themes emerged: (1) psycho-social disability associated with dental procedures, (2) physical disability associated with dental problems, (3) reliance on dentist's advice for treatment and (4) self-management to preserve treated teeth. Patients undergoing endodontic retreatment reported significant time loss from work and were less informed of alternative treatment options. However, they were pleased with the aesthetics of their teeth, especially if new crowns were made. Patients undergoing surgery experienced anxiety related to loss of control during surgery and apprehension on visualizing the wound post-surgery. They reported more impact on their diet, social interaction and sleep quality and some felt self-conscious due to post-treatment gingival recession. Patients in both groups placed great trust in professional advice and expressed a clear desire to maintain their natural dentition. There was low awareness regarding long-term care and future sequelae of their treated tooth.

CONCLUSIONS

Patients reported different psycho-social and physical impacts following endodontic retreatment and apical surgery. Patients undergoing endodontic retreatment were more satisfied with aesthetic outcomes but experienced greater impact related to complexities and length of time taken for treatment. Patients undergoing surgery were better informed of treatment options but experienced greater physical and psycho-social disability during the recovery phase. Clinicians could consider incorporating findings from this study into the patient-dentist discussion.

Healing after surgical retreatment at four time points: A retrospective study

AIM

To evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 months post-operatively, and to search for prognostic factors that may affect the outcome.

METHODOLOGY

Clinical records and intraoral periapical radiographs were collected from patients who had undergone surgical retreatment between 2009 and 2015 and attended 6-, 12-, 24- and 48-month follow-up visits. Surgical retreatment was performed by one endodontist and involved minimal root-end resection and maximal length root-end preparation using prebent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing, based on clinical and radiographic findings. The complete and incomplete categories were pooled and considered successes, while uncertain and unsatisfactory outcomes were considered failures. Changes in healing outcome were analysed using the McNemar-Bowker test, and prognostic factors were analysed using univariate analysis.

RESULTS

The study cohort included 297 patients with 384 teeth. The overall success rate after 48 months was 90.6% compared with 88.5%, 93% and 92.4% after 6, 12 and 24 months respectively. Age, gender, presence of isthmus and length of canal preparation had no significant influence on the outcome. Lesion size and tooth type had a significant influence only after 6 and 12 months, respectively, with no significant differences at other time points. Fifty per cent of the teeth classified as unsatisfactory or uncertain healing at the 6 months follow-up improved to incomplete or complete healing after 12 months. None of the cases classified as unsatisfactory healing after 12 months subsequently improved, and only 2 cases that were classified as uncertain healing after 12 months improved after 24 months.

CONCLUSIONS

Surgical retreatment was found to be a predictable procedure with a high success rate of 90.6% after 4 years. Over the follow-up periods, only a minor regression in the success rate was found. The 12 months follow-up results closely indicated the long-term outcome of surgical retreatment.

A Comparative Analysis of the Piezoelectric Ultrasonic Appliance and Trephine Bur for Apical Location: An In Vitro Study

To compare and contrast the accuracy of piezoelectric ultrasonic insert (PUI) and trephine bur (TB) osteotomy site preparation techniques for apical location. (1) Material and methods: A total of 138 osteotomy site preparations were randomly distributed into one of two study groups. Group A: TB technique (n = 69) and B: PUI technique (n = 69). A preoperative cone-beam computed tomography scan and an intraoral scan were performed and uploaded to implant-planning software to plan the virtual osteotomy site preparations for apical location. Subsequently, the osteotomy site preparations were performed in the experimental models with both osteotomy site preparation techniques and a postoperative CBCT scan was performed and uploaded into the implant-planning software and matched with the virtually planned osteotomy site preparations to measure the deviation angle and horizontal deviation as captured at the coronal entry point and apical end-point between osteotomy site preparations using Student’s t-test statistical analysis. (2) Results: The paired t-test found statistically significant differences at the coronal entry-point deviations (p = 0.0104) and apical end-point deviations (p = 0.0104) between the TB and PUI study groups; however, no statistically significant differences were found in the angular deviations (p = 0.309) between the trephine bur and piezoelectric ultrasonic insert study groups. (3) Conclusions: The results showed that the TB is more accurate than the PUI for apical location.

Adding Two Antimicrobial Glasses to an Endodontic Sealer to Prevent Bacterial Root Canal Reinfection: An In Vivo Pilot Study in Dogs

Current endodontic procedures continue to be unsuccessful for completely removing pathogens present inside the root canal system, which can lead to recurrent infections. In this study, we aimed to assess the antimicrobial capacity and tissue response of two inorganic bactericidal additives incorporated into a paste root canal sealer on contaminated root dentin in vivo. An experimental study was performed in 30 teeth of five Beagle dogs. After inducing microbiological contamination, root canal systems were treated by randomly incorporating one of two antimicrobial additives into a commercial epoxy-amine resin sealer (AH Plus), i.e., G3T glass-ceramic (n = 10) and ZnO-enriched glass (n = 10); 10 samples were randomized as a control group. After having sacrificed the animals, microbiological, radiological, and histological analyses were performed, which were complemented with an in vitro bactericidal test and characterization by field emission scanning electron microscopy. The tested groups demonstrated a non-significant microbiological reduction in the postmortem periapical index values between the control group and the bactericidal glass-ceramic group (p = 0.885), and between the control group and the ZnO-enriched glass group (p = 0.169). The histological results showed low values of inflammatory infiltrate, and a healing pattern characterized by fibrosis in 44.4% of the G3T glass-ceramic and 60.0% of ZnO-enriched glass. Bactericidal glassy additives incorporated in this root canal sealer are safe and effective in bacterial reduction.

A Digital Microscopic Inspection of Dentinal Defects after Using Endodontic Retreatment Files

Aim

The study aimed at evaluating the incidence of dentinal defects after root canal retreatment with ProTaper Universal retreatment (PTUR) and XP-endo Shaper and Finisher R (XP).

Materials and Methods

Sixty extracted single-rooted human premolars were selected and divided into 4 groups of 15 teeth each. In the negative control group, the teeth were left unprepared. In the positive control group, the teeth were prepared with ProTaper Next and obturated with no further retreatment. In the PTUR and XP groups, the teeth were prepared and obturated followed by removal of the filling material at body temperature using PTUR and XP instruments, respectively. The roots were then sectioned at 3, 6, and 9 mm from the apex and observed under a digital microscope to detect defects.

Results

PTUR group showed significantly higher (p value <0.05) incidence of defects than the other groups. Comparison of no defects versus defects between groups in different areas of root canals demonstrated significant difference among the groups in the apical and cervical regions.

Conclusion

Within the limitations of the present study, PTUR files created significantly more dentinal defects than XP files, with most of those defects at the cervical and apical areas of the root canals.

Efficacy of Computer-Aided Static Navigation Technique on the Accuracy of Endodontic Microsurgery. A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to analyze the efficacy of the computer-aided static navigation technique on the accuracy of root apex location in endodontic microsurgery.

MATERIAL AND METHODS

A systematic literature review and meta-analysis, based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, of clinical studies that evaluated the apex location rate of the computer-aided static navigation techniques applied to endodontic microsurgery. A total of four databases were consulted in the literature search: Pubmed-Medline, Scopus, Cochrane, and Web of Science. After eliminating duplicated articles and applying the inclusion criteria, seven articles were selected for the qualitative and the quantitative analysis.

RESULTS

The root apex location success rate stated at 96.8% (confidence interval (CI): 93.0-100%) of the cases performed through a computer-aided static navigation technique. The prediction interval ranges from 91.4% to 100%. The meta-analysis did not detect heterogeneity between the combined studies (Q-test = 6.15; p-value = 0.407; I2 = 2.4%). The computer-aided static navigation techniques showed a root apex location success rate 27 times higher than conventional endodontic microsurgery procedures (Q test = 0.80; p = 0.671; I2 = 0%). Three studies of computer-aided static navigation techniques and control group were compared using a random effects model with the Mantel-Haenszel method with a statistically significant odds success ratio of 27.7, with a 95% confidence interval between 11.3 and 68.1 (z test = 7.23; p < 0.0001).

CONCLUSIONS

According to in vitro studies analyzed, endodontic microsurgeries performed through computer-aided static navigation techniques show a high precision.

Retrievability of bioceramic-based sealers in comparison with epoxy resin-based sealer assessed using microcomputed tomography: A systematic review of laboratory-based studies

Aim:

The objective was to evaluate the retrievability of bioceramic sealers in comparison with epoxy resin-based sealers assessed using microcomputed tomography.

Materials and Methods:

Four reviewers independently conducted a systematic literature search in four electronic databases. The risk of bias was assessed using modified Joanna Briggs Institute Critical Appraisal tools for Quasi-Experimental Studies.

Results:

Ten articles were included in this review and all had a moderate risk of bias. The results across the included articles were inconsistent with some indicating easier/difficult removal of bioceramic sealers, while others indicate no difference. The studies varied in terms of the type of bioceramic sealer used, root canal anatomy, and retreatment techniques followed. Due to heterogeneity, only a qualitative analysis was performed and no meta-analysis was conducted.

Conclusion:

The quality of evidence is low and no definitive conclusion could be derived regarding the retrievability of bioceramic sealer/AH plus sealer from the root canals during retreatment procedures.

Nonsurgical endodontic management of mandibular first premolar with incomplete root-end resection

The complexity of the nonsurgical endodontic retreatment should be weighed against the benefit of surgical approach. This case report describes uncommon diagnosis and successful nonsurgical endodontic management of mandibular first premolar with a previous history of failed apicoectomy and incomplete root-end resection using mineral trioxide aggregate and cone-beam computed tomography.

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.

Preserving the Neurovascular Bundle in Targeted Endodontic Microsurgery: A Case Series

Endodontic microsurgery encompasses the use of microscopy, specialized instruments, and advanced imaging with cone-beam computed tomographic (CBCT) imaging. This treatment modality results in high clinical success rates and facilitates the enucleation of osteolytic lesions, the resection of apical root canal complexities harboring persistent bacterial biofilms, and the evaluation of possible root defects and fractures. However, there is the risk of injury to important anatomic structures, particularly when treating posterior teeth. Neurovascular bundles are among these structures at risk for injury. Fortunately, high-resolution CBCT scans can be used to detect these structures that are known to have a high anatomic variability. In addition, CBCT information can be combined with high-resolution intraoral scans to plan, design, and fabricate surgical guides to be used in a targeted endodontic microsurgery (TEMS) approach. We report 3 cases with previous endodontic treatment having persistent apical periodontitis that were treated with TEMS to avoid damage to the neurovascular bundles at risk of injury. In the first case, the palatal root of tooth #14 was adjacent to the greater palatine artery. In the second case, the mental nerve exited through 2 separate foramina close to the predictive osteotomy site for the mesial root of tooth #19. In the third case, the posterior superior alveolar artery was in close proximity to the mesiobuccal root of tooth #14. Collectively, these cases illustrate the diagnostic value of CBCT imaging for detecting neurovascular bundles and the use of TEMS to mitigate the risk of injury to these important structures. Thus, the combination of CBCT imaging and TEMS can potentially minimize the risk of intraoperative complications and postoperative sequelae while increasing the predictability of endodontic microsurgeries in complex cases.

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.

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.

The application of "bone window technique" using piezoelectric saws and a CAD/CAM-guided surgical stent in endodontic microsurgery on a mandibular molar case

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical ‘bone-window technique’ using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

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.

Evaluation of Two Shaping Systems and Two Ultrasonic Irrigation Devices in Removing Root Canal Filling Material from Mesial Roots of Mandibular Molars: A Micro CT Study

We assessed the efficiency of two shaping file systems and two passive ultrasonic irrigation (PUI) devices for removing filling material during retreatment. The mesial canals from 44 extracted mandibular molars were prepared and obturated. The teeth were randomly divided into two groups, and then one group was retreated with Reciproc R25 (VDW, Munich, Germany) (n = 44) and the other group was retreated with 2Shape (TS, Micro Mega, Besançon, France) (n = 44). A micro-computed tomography (CT) scan was taken before and after the retreatment to assess the volume of the filling material remnants. The teeth were then randomly divided into four groups to test two different PUI devices: Irrisafe (Satelec Acteon Group, Merignac, France) and Endo Ultra (Vista Dental Products, Racine, WI, USA). The teeth in Group A were retreated with 2Shape to test the Endo Ultra (n = 22) device, the teeth in Group B were retreated with 2Shape in order to test the Irrisafe (n = 22) device, the teeth in Group C were retreated with Reciproc to test the Endo Ultra (n = 22) device, and Group D was retreated with Reciproc to test the Irrisafe (n = 22) device. A third micro-CT scan was taken after the retreatment to test the PUIs. The percentage of Gutta-Percha (GP) and sealer removed was 94.75% for TS2 (p < 0.001) and 89.3% for R25 (p < 0.001). The PUI significantly enhanced the removal of the filling material by 0.76% for Group A (p < 0.001), 1.47% for Group B (p < 0.001), 2.61% for Group C (p < 0.001), and by 1.66% for Group D (p < 0.001). 2Shape was more effective at removing the GP and sealer during retreatment (p = 0.018). The supplementary approach with PUI significantly improved filling material removal, with no statistical difference between the four groups (p = 0.106).

Long-term survival of teeth in the posterior region after apical surgery

Oftentimes the discussion of long-term success rates and treatment modalities becomes a central issue in consultations with patients. The aim of this study was to retrospectively evaluate survival rates of teeth after apicoectomy in an established private practice for Oral and Maxillofacial Surgery in Kiel, Germany. All teeth treated with apicoectomy between 2001 and 2006 were included. Treatment success was previously defined as preservation of the tooth. Putative influence factors on success as kind and quality of endodontic treatment, additional intraoperative endodontic filling, inflammatory status, tooth mobility, and pre- and postoperative X-rays were further evaluated. A total of 149 teeth could be included. The mean observation period was 6.3 (SD: 4.4) years. In all, 48.3% of these teeth could be retained after a 10-year period. Teeth that received an additional retrograde root canal filling during surgery resulted in a significantly higher success rate (p = 0.0237) compared to those with orthograde root canal fillings or without additional endodontic treatment. The quality of endodontic treatment had no impact (p = 0.125). Our results suggest that apical surgery is a reliable procedure to treat and ensure the survival of symptomatic teeth in the posterior region for several years. A significant improvement was further determined for a retrograde filling.

Efficacy of ProTaper NEXT Compared with Reciproc in Removing Obturation Material from Severely Curved Root Canals: A Micro-Computed Tomography Study

INTRODUCTION

The aim of this study was to compare the remaining root canal obturation, volume of dentin removed, and apical transportation after retreatment of severely curved root canals by using Reciproc (REC) or ProTaper NEXT (PTN) systems.

METHODS

Twenty-eight mesial canals of mandibular molars were instrumented and then obturated with gutta-percha and sealer and allocated into 2 balanced groups (n = 14), the REC group (R25 file) and the PTN group (X3 and X2 files). Micro-computed tomography analysis was performed to assess the percentage of residual obturation material, the amount of dentin removed, and apical transportation. The effective time for the removal of obturation and procedural errors were recorded.

RESULTS

Obturation was effectively removed from the root canal in the REC and PTN groups (P ≤ .001), and the percentages of remaining obturation material were similar between both groups (84.8% PTN vs 86.5% REC) (P > .05). The amount of dentin removed (3.17 ± 2.64 mm(3) PTN versus 3.50 ± 2.82 mm(3) REC), apical transportation (at 1 mm: 0.096 ± 0.189 mm PTN versus 0.093 ± 0.186 mm REC; at 3 mm: 0.059 ± 0.069 mm PTN versus 0.082 ± 0.080 mm REC; at 5 mm: 0.097 ± 0.093 mm PTN versus 0.133 ± 0.138 mm REC), and the working time (269.69 ± 19.25 seconds PTN versus 268.62 ± 16.37 seconds REC) were also similar in both groups (P > .05). One file fractured in the REC group.

CONCLUSIONS

Both systems were equally effective in the removal of obturation from severely curved canals and can be used for retreatment. Neither system could completely remove the obturation material; therefore, additional techniques are needed to improve cleaning of the root canal.

Relationship between the Mental Foramen, Mandibular Canal, and the Surgical Access Line of the Mandibular Posterior Teeth: A Cone-beam Computed Tomographic Analysis

INTRODUCTION

The purpose of this study was to investigate the relationships between the location of the mental foramen (MF) and the mandibular canal (MC) and the surgical access line (SAL) of the mandibular posterior teeth using cone-beam computed tomographic (CBCT) scans.

METHODS

CBCT scans of 204 subjects ranging in age from 18-76 years old were evaluated. The vertical and horizontal distances from the MF to the SAL of the mandibular premolars and first molars and the vertical distance from the MC to the SAL of the second premolars and first molars were measured via CBCT scans.

RESULTS

The average vertical distance between the MF and the SALs showed significant increases sequentially from the first premolars to the distal roots of the first molars, and the shortest average distance of 2.74 mm was obtained for the first premolars. The SALs of the second premolars were the closest to the MF in the horizontal direction with an average distance of 1.5 mm. In 19.9% of the cases, the vertical and horizontal distances between the MF and the SALs of the second premolars were less than 2 mm. In addition, the MF was located superior to the root apices in 6.62% of the cases. The majority of the SALs were located at a vertical distance from the MC that was more than 2 mm. Men and women exhibited significant differences in both the horizontal distance from the MF to the SALs of the first premolars and the vertical distance from the MC to the SALs of the second premolars.

CONCLUSIONS

To improve the success of endodontic microsurgery, adequate knowledge of the anatomic relationships between the location of the MF and MC and the SAL of the mandibular posterior teeth is indispensable to surgeons.

Apicoectomy of maxillary anterior teeth through a piezoelectric bony-window osteotomy: two case reports introducing a new technique to preserve cortical bone

Two case reports describing a new technique of creating a repositionable piezoelectric bony window osteotomy during apicoectomy in order to preserve bone and act as an autologous graft for the surgical site are described. Endodontic microsurgery of anterior teeth with an intact cortical plate and large periapical lesion generally involves removal of a significant amount of healthy bone in order to enucleate the diseased tissue and manage root ends. In the reported cases, apicoectomy was performed on the lateral incisors of two patients. A piezoelectric device was used to create and elevate a bony window at the surgical site, instead of drilling and destroying bone while making an osteotomy with conventional burs. Routine microsurgical procedures - lesion enucleation, root-end resection, and filling - were carried out through this window preparation. The bony window was repositioned to the original site and the soft tissue sutured. The cases were re-evaluated clinically and radiographically after a period of 12 - 24 months. At follow-up, radiographic healing was observed. No additional grafting material was needed despite the extent of the lesions. The indication for this procedure is when teeth present with an intact or near-intact buccal cortical plate and a large apical lesion to preserve the bone and use it as an autologous graft.