Outcome of secondary root canal treatment: a systematic review of the literature

Prevalence, predictive factors and clinical course of persistent pain associated with teeth displaying periapical healing following nonsurgical root canal treatment: a prospective study

AIMS

To investigate the prevalence, pain catastrophizing and other predictive factors and clinical course of persistent pain/discomfort associated with teeth displaying periapical healing following nonsurgical root canal treatment (NSRCT).

METHODOLOGY

One hundred and ninety-eight patients (264 teeth) who had NSRCT were reviewed at 5-14 months, postoperatively. Teeth with persistent post-treatment pain or discomfort, plus evidence of periapical healing were further monitored 0.5, 4 and 10 years later. Pain Catastrophizing Scale (PCS) and Short Form of the McGill Pain Questionnaire (SF-MPQ) were completed. Predictive factors were investigated using logistic regression models.

RESULTS

Twenty-four per cent (60/249) of teeth displaying periapical healing at first review were associated with persistent pain or discomfort. Fifty-five teeth monitored 6-7 months later were associated with reduction in pain (17/30) or discomfort (7/25). Cone beam computed tomography (CBCT) of eight teeth with persistent symptoms and complete periapical healing (by conventional radiographs) revealed distinct, small apical radiolucencies (n = 3) or root apex fenestration through the buccal plate (n = 2). History of chronic pain (headache, temporo-mandibular joint, masticatory muscle, neck, shoulder or back pain; P = 0.005), preoperative pain (P = 0.04), responsive pulp (P = 0.009), tooth crack (P = 0.05) and small periapical radiolucency (P = 0.005) were significant predictive factors. The PCS revealed 16 patients (22 teeth) were catastrophizers (PCS ≥ 30), but this had no influence on post-treatment symptoms (P = 0.5).

CONCLUSIONS

Persistent pain or discomfort associated with teeth showing periapical healing at the first review after NSRCT, decreased in intensity in most cases over the following 6 months. Longer-term follow-up revealed spontaneous improvement or symptom resolution in the majority of those with confirmed radiographic the absence of periapical disease. Five predictive factors (history of chronic pain, teeth with responsive pulps, association with pain, diagnosis of tooth crack before treatment and diameter of preoperative radiolucency) were identified.

Assessing a training programme for primary care dental practitioners in endodontics of moderate complexity: Pilot data on skills enhancement and treatment outcomes

Aims

To explore the impact of dedicated training to extend the skills of primary care practitioners on the quality of endodontic care, using clinical, radiographic and patient-related outcomes.

Methods

The quality of endodontic treatment performed at the beginning and end of training to become dentists with extended skills (DES) in endodontics was assessed in vitro and in vivo from endo-training blocks and self-reported logbooks containing clinical notes and radiographs respectively. The quality of endodontic care delivered by DES post-training was measured using clinical and radiographic outcomes. Patient-related outcomes were assessed using a self-report questionnaire, including the Oral Health Impact Profile – Endodontic Outcome Measure (OHIP-EOM).

Results

Data on eight dentists were examined pre-and post-training, five of whom participated in further follow-up investigations on the quality of endodontic care delivered to their patients. Significant improvements in skills were seen for all domains in vitro (p <0.05), and for all domains of the clinical treatment process, and achieving the correct working length of the root filling as seen by radiography in vivo (p <0.05). The quality of the clinical process was maintained following training. Positive patient outcome (OHIP-EOM) scores were recorded (mean score of 34.72, SD = 10.74, n = 120 pre-treatment and 25.85, SD = 7.74, n = 47 representing reduced impact at follow-up). The majority of patients reported being satisfied, or very satisfied, with the service they received (72.5%, n = 98); would use the service again (68.1%, n = 92); and would recommend the service to friends and family (74.8%, n = 101).

Conclusions

Findings suggest that training for dentists working in practice can be successful in enhancing skills and changing practice, with evidence of high patient satisfaction and good clinical and patient-related outcomes. Pilot results must be interpreted with caution and further research is required.

Current and future options for dental pulp therapy

Dental pulp is a connective tissue and has functions that include initiative, formative, protective, nutritive, and reparative activities. However, it has relatively low compliance, because it is enclosed in hard tissue. Its low compliance against damage, such as dental caries, results in the frequent removal of dental pulp during endodontic therapy. Loss of dental pulp frequently leads to fragility of the tooth, and eventually, a deterioration in the patient’s quality of life. With the development of biomaterials such as bioceramics and advances in pulp biology such as the identification of dental pulp stem cells, novel ideas for the preservation of dental pulp, the regenerative therapy of dental pulp, and new biomaterials for direct pulp capping have now been proposed. Therapies for dental pulp are classified into three categories; direct pulp capping, vital pulp amputation, and treatment for non-vital teeth. In this review, we discuss current and future treatment options in these therapies.

Immunological profile of teeth with inflammatory periapical disease from chronic liver disease patients

AIM

To evaluate the mRNA expression levels of the cytokines interferon-γ, tumour necrosis factor-α, interleukin (IL)-1β, IL-10, IL-6, VEGF, and AGT and the chemokine CCL2/MCP-1 in periapical interstitial fluid associated with root canal infections before and after the reduction of the bacterial load using a cleaning procedure.

METHODOLOGY

The case group included 11 patients with chronic liver disease, and the control group included 11 healthy patients. Clinical samples were taken from teeth with pulp necrosis. After cleaning and drying the canal, three paper points were introduced into the root canal and passed through the root apex (2 mm) into the periapical tissues for 1 min. The samples were collected immediately after root canal cleaning and 7 days later to characterize those gene expression levels using real-time PCR. The data were subjected to the Shapiro-Wilk and the Wilcoxon tests.

RESULTS

In the control group, significantly increased expression of the pro-inflammatory cytokines IFN-γ and TNF-α was observed in teeth with restrained bacterial loads (day 7) (P < 0.05). Similarly, increased TNF-α expression was found on day 7 in the liver group (P < 0.05). No differences were observed in the expression levels of the IL-1β, IL-10 and, IL-6, MCP-1/CCL-2 and VEGF between the first collection (day 0) and second collection (day 7), over time in either group.

CONCLUSION

Chronic liver disease patients exhibited sufficient immunologic ability showing relatively similar expression levels of cytokines, chemokines and angiogenic factors in periapical samples compared with the responses from no-chronic liver disease patients. The outcomes of this study suggest that liver impairment did not compromise the periapical immune response.

Tooth Survival after Surgical or Nonsurgical Endodontic Retreatment: Long-term Follow-up of a Randomized Clinical Trial

INTRODUCTION

The aim of the study was to determine long-term tooth survival after endodontic retreatment and whether the presence of intraradicular posts influences the outcome.

METHODS

Ninety-five teeth were randomly assigned to surgical or nonsurgical endodontic retreatment. Forty-seven teeth in 45 patients were treated by conventional endodontic surgery and 48 teeth (47 patients) by nonsurgical retreatment, including the removal of intraradicular posts in 37 (77%). The outcome was tooth survival; follow-up continued until the tooth had been extracted, at least 10 years had elapsed since retreatment, the patient declined further follow-up, or the patient died. The Fisher exact test was used to analyze differences between the groups.

RESULTS

The median follow-up time was 10.1 years (range, 0.0-15.6 years). The overall survival rate was 76%, with no significant differences in long-term tooth survival between retreatment methods or the presence of an intraradicular post. The reasons for tooth extraction were related to the retreatment method. Vertical root fractures were significantly more frequent in the nonsurgical group when retreatment included post removal (P = .036).

CONCLUSIONS

There was no significant difference in long-term tooth survival after surgical or nonsurgical retreatment. The presence of intraradicular posts did not affect long-term tooth survival, but for teeth with posts, those retreated nonsurgically were more frequently extracted because of vertical root fractures than those retreated surgically (P = .036). The major limitations of the study were a smaller sample size and the use of outmoded retreatment techniques.

Feasibility of assessing training of primary care dental practitioners in endodontics of moderate complexity: mapping process and learning

Objectives

To explore the feasibility of measuring quality of endodontic care provided by general dental practitioners (GDPs), using clinical, radiographic and patient-related outcomes, as well as understanding practitioner views and estimating financial costs.

Methods

Multi-faceted mixed-methods two-part study involving retrospective analysis of the educational component (course assessments, endodontic training blocks and analysis of a sample of teeth treated at the beginning and end of training), and prospective analysis of patients treated by these dentists after completion of training.

Participant

Dentists working in and patients treated in primary dental care in London.

Intervention

Twenty-four-month training in endodontics.

Comparison

Dentists enrolled in the training at different time points.

Outcome

Measuring outcome of endodontic treatment.

Results

Eight dentists (mean 36 years, SD = 8.2 years) participated in training. Subsequently, five of these dentists (mean 34.2 years, SD = 7.08 years) contributed to the prospective study and recruited 135 patients. Thirty-five patients completed all patient-related outcome questionnaires, and of these there were 16 cases with complete clinical and radiographic data (12%) at follow-up (10.1–36.4 months). Preliminary analysis revealed that a minimum of 45 cases of complete data would be required for multivariate analysis, requiring the recruitment of in excess of 375 patients to future studies to account for this level of loss to follow-up.

Conclusions

Findings suggest it is possible to carry out mixed-methods and treatment-related outcome-based research in primary care. Measurement/data capture tools developed were tested and used successfully in measuring the adherence to treatment processes and outcome of endodontic treatment.

Comparison of the effectiveness of various rotary and reciprocating systems with different surface treatments to remove gutta-percha and an epoxy resin-based sealer from straight root canals

AIM

To compare the Reciproc Blue, Reciproc and ProTaper Universal Retreatment systems with regard to the effective removal of epoxy resin-based sealer and gutta-percha during the retreatment of oval, straight root canals.

METHODOLOGY

Forty-five extracted, human mandibular first premolars with single straight oval canals were selected on the basis of cone beam computed tomography evaluations. The root canals were instrumented with the ProTaper Next system up to the X2 file, and filled with gutta-percha and epoxy resin-based sealer using the cold lateral condensation technique. After 1 month, the samples were randomly divided into three groups (n = 15) according to the retreatment system used: Reciproc Blue R40, Reciproc R40 and ProTaper Universal. The specimens were scanned at the resolution of 1.2 μm by a microcomputed tomography device after the root filling and retreatment procedures, and the decrease in the volume of filling material after each retreatment protocol was measured. The results were analysed using the Kruskal-Wallis test and additional box-and-whisker plots.

RESULTS

Although the volume of the filling material decreased significantly in all three groups (P < 0.05), none of the systems removed the material completely. The Reciproc system removed significantly more material than the ProTaper Universal (P < 0.001) and Reciproc Blue (P = 0.005) systems, with the latter two exhibiting equal volumes of remaining material (P = 0.068).

CONCLUSION

The Reciproc system was more effective than the Reciproc Blue and ProTaper Universal Retreatment systems during the removal of filling material from oval, straight canals, although none of the systems completely removed the filling material.

Regenerative Endodontics for Adult Patients

The goal of endodontics is to save teeth. Since inception, endodontic treatments are performed to obturate disinfected root canals with inert materials such as gutta-percha. Although teeth can be saved after successful endodontic treatments, they are devitalized and therefore susceptible to reinfections and fractures. The American Association of Endodontists (AAE) has made a tremendous effort to revitalize disinfected immature permanent teeth in children and adolescents with diagnoses including pulp necrosis or apical periodontitis. The American Dental Association (ADA) in 2011 issued several clinical codes for regenerative endodontic procedures or apical revascularization in necrotic immature permanent teeth in children and adolescents. These AAE and ADA initiatives have stimulated robust interest in devising a multitude of tissue engineering approaches for dental pulp and dentin regeneration. Can the concept of regenerative endodontics be extended to revitalize mature permanent teeth with diagnoses including irreversible pulpitis and/or pulp necrosis in adults? The present article was written not only to summarize emerging findings to revitalize mature permanent teeth in adult patients but also to identify challenges and strategies that focus on realizing the goal of regenerative endodontics in adults. We further present clinical cases and describe the biological basis of potential regenerative endodontic procedures in adults. This article explores the frequently asked question if regenerative endodontic therapies should be developed for dental pulp and/or dentin regeneration in adults, who consist of the great majority of endodontic patients.

Increased interleukin 1α and interleukin 1β expression is involved in the progression of periapical lesions in primary teeth

BACKGROUND

Interleukin 1 (IL-1) is involved in bone resorption. However, the role of IL-1 in periapical lesions characterized by periapical bone destruction in primary teeth has not yet been fully elucidated. This study aimed to detect the distribution and expression of IL-1 in periapical lesions in primary teeth and assess the relationship between the cytokines and the degree of inflammatory cell infiltration.

METHODS

A total of 106 chronic periapical lesions in primary teeth were harvested. Haematoxylin and eosin (H&E) staining was used to determine the histological type and the inflammatory cell infiltration grade (mild, moderate, and severe), and immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution and expression of IL-1α and IL-1β.

RESULTS

Of the 106 chronic periapical lesion samples, there were 85 cases of periapical granuloma, accounting for 80.19% of the total samples, and 21 cases of radicular cysts, accounting for 19.81%; no cases of abscess were detected. Immunohistochemistry results showed that both IL-1α and IL-1β were expressed in periapical granulomas and cysts. ELISA results showed that IL-1α and IL-1β levels were higher in the periapical granuloma group than in the radicular cyst and normal control groups (P < 0.05). In the periapical granuloma group, IL-1α and IL-1β were detected at higher levels in the severe inflammatory cell infiltration subgroup than in the mild-inflammatory cell infiltration subgroup (P < 0.05), and IL-1β expression was also higher in the moderate inflammatory cell infiltration subgroup than in the mild inflammatory cell infiltration subgroup (P < 0.01). A significant positive correlation was observed between the protein expression levels of IL-1α and IL-1β and the inflammation grade in periapical granulomas from primary teeth (P < 0.05).

CONCLUSION

Expression levels of the cytokines IL-1α and IL-1β in periapical granulomas from primary teeth increased with increasing inflammatory severity and appeared to be a contributing factor to the progression of periapical lesions.

Restoring root-canal treated molars: Cost-effectiveness-analysis of direct versus indirect restorations

OBJECTIVES

Root-canal treated molars can be directly restored, usually using resin-based-composite restorations (RBCs), or indirectly restored using full or partial crowns (FCs/PCs). Both the initial treatment costs and the risks of restorative and endodontic complications differ between RBCs and FCs/PCs. We aimed to assess the cost-effectiveness of RBCs versus FCs/PCs for restoring root-canal treated molars.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from large cohort studies or systematic reviews. Costs were estimated using fee-items catalogues of public and private German insurance. A Markov-model was constructed to follow up a root-canal treated molar receiving different restorations in an initially 50-year-old patient over his lifetime. Monte Carlo-microsimulations were performed to assess lifetime costs and effectiveness (tooth retention time), and the resulting cost-effectiveness.

RESULTS

RBCs were less costly than FCs/PCs (749 Euro versus 782 Euro), but also less effective (22 years versus 24 years), the incremental-cost-effectiveness-ratio was 10.80 Euro/year. This ratio increased if costs for direct restorations decreased, or costs for indirect restorations increased. If no teeth were replaced, RBC was far more cost-effective (the incremental cost-effectiveness ratios was 52.95 Euro/year). If all teeth were replaced, FC was both more effective and less costly.

CONCLUSIONS

RBCs showed lower costs, but also lower effectiveness than FCs/PCs. Consequently, the cost-effectiveness of both strategies depended on the willingness-to-pay of patients or other payers, i.e. their willingness to invest in higher effectiveness. Clinically, a large number of tooth, patient and dentist-related factors will impact on decision-making and should be considered.

CLINICAL SIGNIFICANCE

We found composite restorations to be less costly, but also less effective than indirect restorations for root-canal treated teeth. Over a long-term period, the initial treatment costs and associated cost-differences between strategies may be outweighed by costs of follow-up treatments.

A web-based endodontic case difficulty assessment tool

OBJECTIVE

To develop a web-based tool to facilitate identification, evaluation and management of teeth requiring endodontic treatment.

MATERIALS AND METHODS

Following a literature search and thorough analysis of existing case difficulty assessment forms, the web-based tool was developed using an online survey builder (Qualtrics, Qualtrics Lab, UT, USA). Following feedback from a pilot study, it was refined and improved. A study was performed, using the updated version (EndoApp) on a cohort (n = 53) of dental professionals and dental students. The participants were e-mailed instructions detailing the assessment of five test cases using EndoApp, followed by completion of a structured feedback form. Analysis of the EndoApp responses was used to evaluate usage times, whereas the results of the feedback forms were used to assess user experience and relevance, other potential applications and comments on further improvement/s.

RESULTS

The average usage time was 2 min 7 s; the average times needed for the last three (Cases 3-5) were significantly less than the preceding two (Cases 1 & 2) test cases. An overwhelming majority of participants expressed favourable views on user experience and relevance of the web-based case difficulty assessment tool. Only two participants (4%) were unlikely or very unlikely to use EndoApp again. The potential application of EndoApp as an 'educational tool' and for 'primary care triage' was deemed the most popular features and of greater importance than the secondary options of 'fee setting' and as a 'dento-legal justification tool'.

CONCLUSIONS

Within the study limitations, owing to its ability to quantify the level of difficulty and provide guidance, EndoApp was considered user-friendly and helped facilitate endodontic case difficulty assessment. From the feedback, further improvements and the development of a Smartphone App version are in progress.

CLINICAL RELEVANCE

EndoApp may facilitate treatment planning, improve treatment cost-effectiveness and reduce frequency of procedural errors by providing appropriate guidance on endodontic case management.

Rotary Versus Reciprocation Root Canal Preparation: Initial Clinical Quality Assessment in a Novice Clinician Cohort

INTRODUCTION

Reports comparing clinical outcomes using nickel-titanium (NiTi) reciprocating instruments with other instrumentation modalities are scarce. This study examined initial shaping outcomes after an instrumentation change of root canal instrumentation technique in a doctor of dental surgery educational program. Student characteristics, faculty/student ratio, facility, and overall endodontic treatment guidelines remained unchanged.

METHODS

A total of 200 nonsurgical initial molar root canal treatments completed by third-year dental students were evaluated. The cases were examined regarding the number of treatment appointments, access cavity preparation, canal taper, canal transportation, perforations, missed canals, presence of ledges, fractured instruments, obturation length, obturation quality, and sealer extrusion. Two independent evaluators determined the number of appointments per case; 4 independent and blinded evaluators analyzed radiographs at 4 treatment stages: preoperative situation, working length, cone fit, and obturation.

RESULTS

The following factors were significantly different between the 2 cohorts: the number of appointments, preparation length, taper, and occurrence of ledges. The WaveOne (Dentsply Sirona, York, PA) cohort had a significantly reduced treatment time compared with hand/GT rotary instrumentation (Dentsply Tulsa Dental, Tulsa, OK) (average of 3.3 vs 4.3 appointments). Appropriate length control and adequate taper were significantly more frequent in the WaveOne group. The frequency of ledges was significantly larger in the hybrid group. Other variables, such as access cavity preparation, canal transportation, perforations, missed canals, fractured instruments, obturation quality, and sealer extrusion, were statistically similar between the 2 groups.

CONCLUSIONS

NiTi reciprocation instrumentation was superior to hybrid hand/NiTi rotary instrumentation in reducing both patient appointments and the incidence of ledging and in improving obturation length and taper in a dental student clinic setting.

Amalgam Alternatives: Cost-Effectiveness and Value of Information Analysis

We aimed to assess the cost-effectiveness of amalgam alternatives—namely, incrementally placed composites (IComp), composites placed in bulk (BComp), and glass ionomer cements (GIC). In a sensitivity analysis, we also included composite inlays (CompI) and incrementally placed bulk-fills (IBComp). Moreover, the value of information (VOI) regarding the effectiveness of all strategies was determined. A mixed public-private-payer perspective in the context of Germany was adopted. Bayesian network meta-analyses were performed to yield effectiveness estimates (relative risk [RR] of failure). A 3-surfaced restoration on a permanent molar in initially 30-y-old patients was followed over patients’ lifetime using a Markov model. Restorative and endodontic complications were modeled; our outcome parameter was the years of tooth retention. Costs were derived from insurance fee items. Monte Carlo microsimulations were used to estimate cost-effectiveness, cost-effectiveness acceptability, and VOI. Initially, BComp/GIC were less costly (110.11 euros) than IComp (146.82 euros) but also more prone to failures (RRs [95% credible intervals (CrI)] were 1.6 [0.8 to 3.4] for BComp and 1.3 [0.5 to 5.6] for GIC). When following patients over their lifetime, IComp was most effective (mean [SD], 41.9 [1] years) and least costly (2,076 [135] euros), hence dominating both BComp (40.5 [1] years; 2,284 [126] euros) and GIC (41.2 years; 2,177 [126] euros) in 90% of simulations. Eliminating the uncertainty around the effectiveness of the strategies was worth 3.99 euros per restoration, translating into annual economic savings of 87.8 million euros for payers. Including CompI and IBComp into our analyses had only a minimal impact, and our findings were robust in further sensitivity analyses. In conclusion, the initial savings by BComp/GIC compared with IComp are very likely to be compensated by the higher risk of failures and costs for retreatments. CompI and IBComp do not seem cost-effective. All alternatives are likely to be inferior to amalgam. The VOI was considerable, and future studies may yield significant economic benefits.

Method of teaching undergraduate students to perform root canal treatment: It's influence on the quality of root fillings

INTRODUCTION

This study aimed to assess whether the method of teaching endodontology influenced the quality of root fillings made by undergraduate students.

MATERIALS AND METHODS

The method of teaching endodontology at our institution was revised. Changes concerned: the programme (ie method of clinical training and summative assessment), and the supervision whilst performing root canal treatment on patients. An intermediate cohort (N=91) comprised partly students attending the former programme (involving patients) and partly students attending the revised programme (without patients). After succeeding in the summative assessment, the quality of the first root filling made by the student in a patient under supervision of either a general dental practitioner or an endodontist was evaluated according to pre-determined criteria. Data were analysed using Cohen's Kappa, Chi-square, Fisher's exact, Mann-Whitney and Kruskal-Wallis tests.

RESULTS

Sixty-two per cent (47 of 76) of root fillings made by students who attended the revised programme were of good quality, in comparison with 47% (seven of 15) of those made by students who attended the former programme (P=.274). Less complex treatments had better quality root fillings if students were supervised by endodontists (88% (14 of 16) good quality) than supervised by general dental practitioners (59% (22 of 37) good quality) (P=.045). Complex treatments did not differ in quality of root fillings for the supervision types (P=.825).

CONCLUSION

The quality of root fillings made by students who attended the revised programme seems at least as high as that of those who attended the former programme. Higher quality root fillings might be obtained under supervision of endodontists than under supervision of general dental practitioners.

Pooled analysis of 1-year recall data from three root canal treatment outcome studies undertaken using cone beam computed tomography

AIM

To provide an estimate of the proportion of successful outcomes of primary and secondary root canal treatments (retreatments) determined by periapical radiographs and cone beam computed tomography (CBCT), a pooled analysis of the data collected from three previous prospective clinical outcome studies was undertaken.

METHODOLOGY

The analysis pooled the 1-year results for 354 teeth, including 123 primary treatments and 231 retreatments. All root canals were instrumented with ProTaper Universal and filled using a warm vertical condensation technique. Comparisons of favourable results between root canal treatments and retreatments and between different tooth types were made using chi-square/Fisher's exact test.

RESULTS

The overall percentage of favourable results was 91% using periapical radiographs and 80% for CBCT (P < 0.001). With CBCT, the percentage of favourable results for primary treatments (84.7%) was not significantly different (P = 0.316) from that of retreatments (77.9%). When assessed by tooth group, the overall percentage of favourable results with CBCT was 75.5%, 90.6% and 91.1% for molar, premolar and anterior teeth, respectively. When CBCT is used to assess the outcome, the proportion of favourable outcomes in molars was significantly lower than that of premolars and anterior teeth (P < 0.05). Teeth with root fillings terminating more than 2 mm short of the radiographic apex had less favourable outcomes (73%) compared to long (83%) and adequate root filling length (84%).

CONCLUSIONS

The proportions of favourable outcomes of primary root canal treatments and retreatments assessed with CBCT were lower when compared to periapical radiographs, and also lower than those historically reported by periapical radiograph-based outcome studies. Considering the very high favourable outcome of anterior teeth and premolars compared to molar teeth, future studies assessing the effect of new materials and techniques on the outcome of root canal treatments should be based on preoperative and postoperative CBCT images, and focus on molar teeth.

Methodological and Reporting Quality of Systematic Reviews and Meta-analyses in Endodontics

INTRODUCTION

The aim of this systematic review (SR) was to evaluate the quality of SRs and meta-analyses (MAs) in endodontics.

METHODS

A comprehensive literature search was conducted to identify relevant articles in the electronic databases from January 2000 to June 2017. Two reviewers independently assessed the articles for eligibility and data extraction. SRs and MAs on interventional studies with a minimum of 2 therapeutic strategies in endodontics were included in this SR. Methodologic and reporting quality were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR) and Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA), respectively. The interobserver reliability was calculated using the Cohen kappa statistic. Statistical analysis with the level of significance at P < .05 was performed using Kruskal-Wallis tests and simple linear regression analysis.

RESULTS

A total of 30 articles were selected for the current SR. Using AMSTAR, the item related to the scientific quality of studies used in conclusion was adhered by less than 40% of studies. Using PRISMA, 3 items were reported by less than 40% of studies, which were on objectives, protocol registration, and funding. No association was evident comparing the number of authors and country with quality. Statistical significance was observed when quality was compared among journals, with studies published as Cochrane reviews superior to those published in other journals. AMSTAR and PRISMA scores were significantly related.

CONCLUSIONS

SRs in endodontics showed variability in both methodologic and reporting quality.

Clinical and Patient-centered Outcomes of Nonsurgical Root Canal Retreatment in First Molars Using Contemporary Techniques

INTRODUCTION

There have been many recent technical advances in modern endodontics that have the potential to affect treatment outcomes. Reports on treatment outcomes using contemporary techniques are relatively scarce, especially in the field of nonsurgical retreatment. The purpose of this study was to determine the success of nonsurgical root canal retreatment in molars using contemporary endodontic techniques.

METHODS

Sixty-three patients referred for retreatment in first molars were enrolled in the study. The retreatment procedures were performed by endodontic residents using a semistandardized treatment protocol. Patients were followed-up at 6, 12, and 24 months. Treatment outcomes were categorized into healed, healing, or nonhealing based on clinical and radiographic criteria. Healed and healing were considered as successes, and nonhealing was considered a failure. Outcomes were also evaluated using patient-centered criteria that included oral health-related quality of life scores and subjective chewing ability.

RESULTS

Fifty-two of the 63 patients were available for final analysis. Five cases (9.6%) were determined to be nonhealing at the last follow-up with new or persistent periapical lesions. Thirty-seven (71.2%) patients had complete resolution of apical periodontitis, and the remaining 10 (19.2%) remained asymptomatic and showed radiographic evidence of healing. Oral health-related quality of life scores and chewing ability improved significantly over time (P < .05), with the biggest increase observed within the first week of treatment completion.

CONCLUSIONS

This study showed that endodontic retreatment using contemporary techniques significantly improved patients' quality of life and chewing ability over time, with a success rate of 90.4% after 2 years.

Micro-CT Evaluation of Gutta-Percha Removal by Two Retreatment Systems

INTRODUCTION

The aim of the present ex vivo research was to compare the remaining filling material and the volumes of dentine removed after retreatment of curved canals with two rotary systems naming ProTaper Universal Retreatment and Mani NRT-GPR using micro-computed tomography (micro-CT).

METHODS AND MATERIAL

Forty mandibular molars containing two completely separated canals, with curvature angle of 25-35° and a curvature radius <10 mm were prepared to the Mtwo instrument 35/0.04 and filled with warm gutta-percha and AH-Plus sealer. The teeth were randomly divided into 2 groups (n=20), according to the retreatment system evaluated: ProTaper Universal Retreatment (PR group) or Mani NRT-GPR (MR group). Retreatment was considered complete when the working length was reached and when smooth dentinal walls were observed, with no evidence of filling material adhered to instruments or in the irrigating solution. Preoperative and postoperative micro-CT images were obtained with an isotropic voxel size of 11.88 µm to observe the volume of residual filling material in the canals and dentine removed after retreatment. Statistical analysis was performed by Student's t-test (P<0.05).

RESULTS

The mean percentage of remaining filling material was 12.96% for PR group and 24.26% for MR group (P=0.0056). The percentage of dentin removal was greater in the PR group (5.02%) than MR group (1.36%) (P=0.0028). Both systems failed to completely remove the filling material from the canals.

CONCLUSION

ProTaper Universal Retreatment system was more effective than Mani NRT-GPR system regarding removal of root filling material and also removed significantly more dentine after retreatment of curved mesial root canals of mandibular molars.

Apical periodontitis in southern Estonian population: prevalence and associations with quality of root canal fillings and coronal restorations

Background

Apical periodontitis (AP) is an inflammatory disease around the apex of a tooth root. Reported prevalence of AP ranges from 27% to 83% while the data about most post-Soviet countries are still missing. Knowing the prevalence of AP within a certain population helps to plan the treatment need and evaluate the success of endodontic interventions. We aimed to collect data about prevalence and determining factors of AP for the first time in Estonia.

Methods

The cross-sectional study included 6552 patients (age 35.5±19.2 years). Radiographic examination was applied to investigate the prevalence of AP and quality of endodontic treatment.

Results

AP was diagnosed in 54.7% of subjects. Endodontically treated teeth were present in 58.2% of subjects. Periapical finding was present in 44.6% of endodontically treated and in 30.8% of untreated teeth.

Out of 181,495 teeth, 52.7% were intact. AP was diagnosed in 6.3% of teeth, 6.9% of teeth were endodontically treated.

Risk factors for AP included caries (OR = 2.30), male gender (OR = 1.44), too short (OR = 1.76) or too long root canal filling (OR = 2.51), root canal filling of low density (OR = 1.61) while not orthodontic appliance. Lower AP risk was associated with restoration of the tooth – filling (OR = 0.45), crown (OR = 0.34) and bridge (OR = 0.33).

Conclusions

AP is highly prevalent in Southern Estonian population. Most cases are associated with root canal-treated teeth. The overall quality of root canal fillings tends to be low, consistent with the mediocre outcome of treatment. Considerable efforts are required to improve the standards of endodontic treatment.

Electronic supplementary material

The online version of this article (10.1186/s12903-017-0429-7) contains supplementary material, which is available to authorized users.

Outcome of secondary root canal treatment filled with Thermafil: a 5-year follow-up of retrospective cohort study

OBJECTIVES

The aim of the present retrospective cohort study was to assess the 5-year outcome and survival of secondary root canal treatments (2°RCT), exploring the influence of pre-, intra-, and post-operative variables.

MATERIALS AND METHODS

One hundred thirty-two endodontically retreated teeth were radiographically and clinically re-examined after 5 years. 2°RCT had been performed during a Masters program following standardized protocols and filled with AH Plus/Thermafil (TF). Pre-, intra-, and post-operative data were collected. The 5-year outcome was blindly evaluated and categorized as healed/diseased on the basis of the periapical index. Bivariate analysis and chi-square test evaluated the association between outcome and 31 demographic/clinical parameters. Multilevel analysis was performed at both patient and tooth level. Statistical significance was calculated at 5% level.

RESULTS

At 5-year evaluation, survival rate was 80% with 7.5% lost for endodontic reasons. Eighty-three percent of the teeth were classified as healed. Multilevel analysis identified significant predictors of increased survival: female gender (p = 0.012), absence of a pre-operative metal post (p = 0.017), conservative apical preparation (diameter size < #35) (p = 0.039), teeth restored with a crown (p = 0.009), and final PAI (after 5 years) ≤ 2 (p = 0.001). Multilevel analysis identified as predictor healing: not being a smoker (p = 0.048) and conservative apical preparation < size #35 (p = 0.037).

CONCLUSIONS

Outcome of 2°RCT filled with Thermafil was successful at 5 years, showing a high rate of survived and healed teeth comparable to that reported previously for other obturation techniques.

CLINICAL RELEVANCE

Present findings confirm 2°RCT as a valid therapeutic option to retain natural teeth.

Uncertain Decision-Making in Primary Root Canal Treatment

OBJECTIVES

A systematic review of literature was conducted to compare the success and survivability of primary root canal interventions.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta Analyses protocol was adopted in this study to systematically assess and report systematic reviews related to success or survival or failure rates of primary root canal interventions. MEDLINE and Cochrane Oral Health Library were both searched by using specific search terms to identify relevant literature, until June 2016. The search was augmented by handsearching. Then, the quality of the included systematic reviews was assessed by using the Revised Assessment of Multiple Systematic Reviews (RAMSTAR) protocol.

RESULTS

Only 9 systematic reviews were identified. The RAMSTAR scores of the included reviews ranged from 43/44 to 29/44. Nevertheless, the later reviews did not provide sufficient evidence or statistically significant evidence to support any of the interventions used during primary root canal treatment. In addition, a number of key steps during primary root canal treatment, such as types of dental files, root canal instrumentation techniques, orthograde obturation materials, and techniques, were not assessed by systematic reviews.

CONCLUSION

The current status of evidence related to the success and survivability of primary root canal interventions is lacking. This puts dentists under marked degrees of uncertainty. Consequently, patients are potentially exposed to health care risks. It is then essential to develop tailored methods and tools for decision-making under uncertainty to aid both dentists and patients engaged in primary root canal treatment.

An audit on technical quality of root fillings performed by undergraduate students

AIM

To evaluate radiographically the technical quality of root fillings performed by undergraduate dental students and to assess whether students were exposed to an appropriate endodontic case mix during their clinical training.

METHODOLOGY

A retrospective audit was undertaken evaluating the clinical records of patients who underwent endodontic procedures during the period from September 2015 to June 2016 in the Dental School at Queen's University Belfast, UK. Two final-year dental students were trained and calibrated to evaluate postoperative intra-oral periapical radiographs of completed root canal treatments using specific assessment criteria. Data were presented as frequencies, percentage and mean ± standard deviation (SD). Comparisons of treatment outcomes between groups (posterior and anterior teeth) were calculated using Fisher's exact test, and the level of significance was set at P < 0.05. Intra- and interexaminer reproducibility was assessed by Kappa statistics.

RESULTS

A total of 222 teeth and 381 canals were assessed, and of those, 253 (66%) of the root fillings were found to be acceptable in all the assessment parameters, namely taper, length and lateral adaptation of the root filling. Subanalysis of individual root filling parameters revealed that 372 canals (97%) exhibited good taper, and 275 canals (72%) were considered to be of an appropriate length, with 89 canals (23%) found to be underfilled and 17 canals (5%) overfilled. Overall 346 (91%) of canals had good lateral condensation. Students treated both single and multirooted teeth, and there was no significant association between tooth type and the quality of root filling provided (P > 0.05).

CONCLUSIONS

In the majority of the teeth treated by undergraduate students at Queen's University Belfast, the technical quality of the root filling was acceptable and students were exposed to an appropriate case mix for endodontic training.

Biofilms in Endodontics-Current Status and Future Directions

Microbiota are found in highly organized and complex entities, known as biofilms, the characteristics of which are fundamentally different from microbes in planktonic suspensions. Root canal infections are biofilm mediated. The complexity and variability of the root canal system, together with the multi-species nature of biofilms, make disinfection of this system extremely challenging. Microbial persistence appears to be the most important factor for failure of root canal treatment and this could further have an impact on pain and quality of life. Biofilm removal is accomplished by a chemo-mechanical process, using specific instruments and disinfecting chemicals in the form of irrigants and/or intracanal medicaments. Endodontic research has focused on the characterization of root canal biofilms and the clinical methods to disrupt the biofilms in addition to achieving microbial killing. In this narrative review, we discuss the role of microbial biofilms in endodontics and review the literature on the role of root canal disinfectants and disinfectant-activating methods on biofilm removal.

Healing of Apical Periodontitis after Nonsurgical Treatment in Patients with Type 2 Diabetes

INTRODUCTION

The purpose of this prospective study was to compare the success of primary root canal treatment between type 2 diabetic and nondiabetic patients and to investigate the effect of periapical healing on glycated hemoglobin (HbA1c) in type 2 diabetic patients with apical periodontitis.

METHODS

Sixty mandibular molars with necrotic pulps and apical radiolucency (size ≥ 2 mm × 2 mm) were included in the study. Based on the HbA1c levels, patients were divided into 2 groups: type 2 diabetic (HbA1c ≥6.5%) and nondiabetic (HbA1c <6.5%). Forty-six teeth were evaluated at the 12-month follow-up time period. The primary outcome measure was the change in apical bone density as determined by the periapical index.

RESULTS

Both the diabetic and nondiabetic group depicted a significant reduction in the periapical score after endodontic treatment at the 12-month follow-up (P < .05). Significantly less periapical healing was observed in the diabetic group (43%) compared with the nondiabetic group (80%) at the 12-month follow-up (P < .05). HbA1c levels in the diabetic group increased at each follow-up after endodontic treatment.

CONCLUSIONS

Diabetes mellitus may have a negative impact on the outcome of endodontic treatment in terms of periapical healing. Nonsurgical endodontic treatment did not improve HbA1c levels in patients with type 2 diabetes.

Root canal treatment outcomes not affected by increasing age of patient

Data sourcesMedline, Cochrane CENTRAL databases; most recent two years of seven journals: (Acta Odontologica Scandinavica; Community Dentistry and Oral Epidemiology; Gerodontology; International Endodontic Journal; Journal of Endodontics; Journal of Oral Rehabilitation; and Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology).Study selectionTooth-based longitudinal prospective and retrospective studies, published in English from January 1950 to August 2013, assessing outcomes of NSRCT in adults with permanent teeth.Data extraction and synthesisStudies were independently selected and reviewed by two reviewers. Standardised items were extracted and compiled into a table of evidence. Study quality was assessed by the Wong Scale-Revised and those that scored less than 18 were excluded. Due to the high heterogeneity in reporting, meta-analysis was not conducted. All of the success criteria were implicitly based upon the presence or absence of apical pathology, and each individual study made internal comparisons of success using the same criteria.ResultsOf the twenty four studies selected, involving more than 17,430 teeth, nine were prospective and fifteen were retrospective studies. The overall mean study quality rating was 23(SD = 3) on the 27-point Wong Scale-Revised. Since the majority of the papers did not report raw numbers, and due to the heterogeneity in reporting, meta-analysis was not performed. In summary, eight prospective and fourteen retrospective studies reported no difference in outcomes, principally success which was defined by the absence of apical disease, with age. One prospective and one retrospective study reported an improvement in success with increasing age.ConclusionsThe moderate evidence indicated that increased patient age does not decrease the success of NSRCT.

A Comparative Study of ProTaper Universal and ProTaper Next Used by Undergraduate Students to Prepare Root Canals

INTRODUCTION

The purpose of this study was to determine whether final-year undergraduate dental students achieved better shaping outcomes using the new ProTaper Next (PTN; Dentsply Sirona, Ballaigues, Switzerland) system to prepare root canals for the first time compared with the existing ProTaper Universal (PTU, Dentsply Sirona) system on which they had trained. A secondary aim was to explore the attitudes and preferences of the students toward both systems.

METHODS

Forty students prepared 1 simulated S-shaped canal using PTN and another with PTU. Images of the canals were saved before and after preparation, and the outcomes assessed included the formation of aberrations and the amount of resin removed at specific points along the canal length. Student opinions relating to PTN and PTU were collected via a questionnaire completed immediately after using the systems. For statistical analysis, the McNemar test was used to compare the incidence of aberrations, and a paired t test was used to analyze the width measurements. Responses to the questionnaire were analyzed using frequencies. Thus, the McNemar test was used for paired binary data and the marginal homogeneity test for categoric data when more than 2 categories were used. Finally, the overall preferences (either PTN or PTU) were analyzed using the sign/binomial test, which is a standard statistical test that allows us to determine if the proportion preferring one or the other is equal or not.

RESULTS

Canal ledges were formed in 30% of the canals prepared with PTU, whereas no ledges were formed with PTN (P < .001). A middle constriction, a form of canal aberration, was created by both systems although it occurred significantly (P = .006) more often with PTN. The "number of files" was judged by students to be significantly higher (P < .001) for PTU compared with PTN. Even though using PTN for the first time, students were more likely to recommend the system to other students for preparing S-shaped canals than PTU (P = .018) and preferred to use PTN in the future (P < .001).

CONCLUSIONS

The students who had previous experience with the use of PTU were able to produce comparable shaping outcomes when they used PTN for the first time. For the preparation of S-shaped canals, the students preferred PTN over PTU in terms of the number of files and would prefer to use it in the future.

Development of Periapical Lesions in Endodontically Treated Teeth with and without Periodontal Involvement: A Retrospective Cohort Study

INTRODUCTION

The purpose of this study was to investigate the incidence of apical periodontitis (AP) in endodontically treated teeth with and without periodontal involvement.

METHODS

The records of 602 patients with 775 root canal-treated teeth were initially examined. Only teeth with adequate root canal filling, adequate coronal restoration, and no AP (periapical index = 1) were selected for further investigation. A total of 194 teeth were included in this cohort study. Age, sex, history of diabetes mellitus, smoking, hypertension, and immunodeficiency disorders were recorded. Two groups were made according to the periodontal status of the patients. The control group included periodontally healthy patients and the periodontal group patients with periodontal disease receiving nonsurgical periodontal treatment. After an observation period of at least 2 years, the incidence of AP was scored using the periapical index. The relationship between patients' variables and AP was conducted using the Cohen kappa test, the chi-square test, odds ratio (OR), and logistic regression analysis.

RESULTS

Newly emerged AP was found in 14% of periodontally involved teeth and in 3% of nonperiodontal involved teeth (P < .05, OR = 5.19, 95% confidence interval). The periodontal condition and hypertension were the only significant factors associated with the presence of AP in the follow-up after univariate logistic regression. Adjusting for hypertension, multivariate logistic regressions showed that periodontal status remained significant (OR = 5.25, 95% CI, P < .05).

CONCLUSIONS

The risk of developing AP in endodontically treated teeth is 5.19 times higher for patients with periodontal disease compared with patients without periodontal disease.

In-Office Application of Fluoride Gel or Varnish: Cost-Effectiveness and Expected Value of Perfect Information Analysis

Application of fluoride gel/varnish (FG/FV) reduces caries increments but generates costs. Avoiding restorative treatments by preventing caries might compensate for these costs. We assessed the cost-effectiveness of dentists applying FG/FV in office and the expected value of perfect information (EVPI). EVPI analyses estimate the economic value of having perfect knowledge, assisting research resource allocation. A mixed public-private-payer perspective in Germany was adopted. A population of 12-year-olds was followed over their lifetime, with caries increments modelled using wide intervals to reflect the uncertainty of caries risk. Biannual application of FV/FG until age 18 years was compared to no fluoride application. Effectiveness parameters and their uncertainty were derived from systematic reviews. The health outcome was caries increment (decayed, missing, or filled teeth; DMFT). Cost calculations were based on fee catalogs or microcosting, including costs for individual-prophylactic fluoridation and, for FG, an individualized tray, plus material costs. Microsimulations, sensitivity, and EVPI analyses were performed. On average and applied to a largely low-risk population, no application of fluoride was least costly but also least effective (EUR 230; 11 DMFT). FV was more costly and effective (EUR 357; 7 DMFT). FG was less effective than FV and also more costly when using individualized trays. FV was the best choice for payers willing to invest EUR 39 or more per avoided DMFT. This cost-effectiveness will differ in different settings/countries or if FG/FV is applied by other care professionals. The EVPI was mainly driven by the individual's caries risk, as FV/FG were significantly more cost-effective in high-risk populations than in low-risk ones. Future studies should focus on caries risk prediction.

Cost-effectiveness of Different Post-retained Restorations

OBJECTIVES

Dentists can choose between metal and fiber post systems to provide post-retained restorations. The risk of tooth loss and other complications differs between different post systems, as do the initial treatment costs. We aimed to assess the cost-effectiveness of (1) cast metal (MC), (2) preformed metal (MP), (3) glass fiber (GF), and (4) carbon fiber (CF) post-retained restorations.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from systematic reviews. Costs were estimated by using fee items and 2016 material costs. A Markov model was constructed to follow up an endodontically treated molar receiving a post-retained crown in an initially 50-year-old patient during his lifetime. Monte Carlo microsimulations were performed to assess lifetime costs and tooth retention time.

RESULTS

MPs were least costly (€692€), retaining teeth for 26.7 years. GFs were more costly (€745€), retaining teeth for 27.6 years. MCs were minimally more effective but also more costly than GFs (€774€). CFs were less effective and most expensive (€825€, 26.7 years). For payers willing to invest more than €60€ per tooth retention year, GF was cost-effective. Payers willing to invest an additional €670€ found MC to be cost-effective. These findings were found robust in sensitivity analyses.

CONCLUSIONS

For payers not willing to invest additional money for longer tooth retention, MP seemed most suitable to retain restorations. For payers with additional willingness to pay, GF seemed suitable, retaining teeth for longer. MC was only cost-effective under very high willingness to pay. CF is not recommendable on the basis of their cost-effectiveness.