A prognostic model for assessment of the outcome of endodontic treatment: Effect of biologic and diagnostic variables

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL SIGNIFICANCE

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

Endodontic Retreatment of a Mandibular Second Molar With a C-shaped Root Canal Configuration: A Case Report

Root canal retreatment in mandibular second molars with C-shaped root canal configurations presents notable challenges. This article presents a case of successful root canal retreatment in a mandibular second molar exhibiting this complex configuration. Achieving a successful endodontic outcome in such cases necessitates a comprehensive understanding of the unique root canal anatomy. Moreover, the employment of advanced instruments and techniques is crucial to effectively address the intricacies of the C-shaped root canal system.

Effectiveness of root canal filling materials and techniques for treatment of apical periodontitis: A systematic review

BACKGROUND

Apical periodontitis (AP) is an inflammatory disease of the apical periodontium as sequelae of pulp death. It is managed by disinfection and filling of the root canal space.

OBJECTIVES

The aim of this systematic review was to investigate whether obturation techniques and materials used for root canal filling led to the management of AP.

METHODS

A systematic review protocol was written following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and registered on the international prospective register of systematic reviews (PROSPERO; CRD42021260275) including two populations, interventions, comparisons, outcomes and time (PICOT) for the research questions querying the effectiveness of obturation techniques (PICOT 1) and materials (PICOT 2) for the management of AP. Electronic searches were conducted on PubMed, ScienceDirect, Scopus and Embase search engines. Searches on International Endodontic Journal, Journal of Endodontics, Clinical Oral Investigations, Journal of Dental Research and Journal of Dentistry websites were also conducted, until May 2021. Both primary (tooth survival) and secondary outcomes were evaluated. The risk of bias was assessed by Cochrane RoB2 for the randomized and ROBINS-I for the nonrandomized trials.

RESULTS

The search strategy identified 1652 studies, with 1600 excluded on the title and abstract screening, leaving 52 studies for full-text screening. In total, 10 studies met the inclusion criteria. The obturation technique and materials used did not affect the outcome of AP. Vertical compaction resulted in faster resolution of periapical lesions. The oral health-related quality of life of patients treated with lateral condensation exhibited poorer outcomes compared with single matched cone after 6 months of recall.

DISCUSSION

The inclusion and exclusion criteria used for this systematic review enabled the capture of all the literature available on the effect of obturation techniques and materials on the outcome of AP. The data were heterogenous, and a number of articles investigating obturation techniques had no information on the materials and techniques used as they looked at the quality of fill.

CONCLUSIONS

Included studies did not find any difference between different procedures (PICOT 1) and materials (PICOT 2). The risk of bias was high, thus the findings should be interpreted with caution.

REGISTRATION

PROSPERO registration number: CRD42021260275.

Effectiveness of root canal treatment for vital pulps compared with necrotic pulps in the presence or absence of signs of periradicular pathosis: A systematic review and meta-analysis

BACKGROUND

Preoperative pulpal status may influence the outcomes of root canal treatment (RCTx) according to various measures used.

OBJECTIVES

To compare the effectiveness of RCTx of teeth with a vital pulp versus a necrotic pulp, using a range of clinical and patient-related outcomes proposed for the development of S3-level clinical practice guidelines.

METHODS

A search was conducted in the PubMed-MEDLINE, Scopus, EMBASE, Google scholar databases and available repositories, followed by hand searches, until 29 March 2022. Clinical studies published in the English language comparing the stipulated outcomes of RCTx of teeth with vital versus necrotic pulp were included. The Newcastle-Ottawa Scale was adapted to assess study quality. Effects of pulpal status were estimated and expressed as risk ratio (RR) using fixed- and random-effect meta-analyses. The quality of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

Twenty-eight studies published between 1961 and 2021 were included. Five studies have investigated the "tooth survival" outcome, four reported pulpal status was not a significant predictor, consistent with meta-analysis findings (RR: 1.00; 95% CI: 1.00, 1.00; n = 3). Seven studies reported pulpal status had no significant influence on postoperative pain, regardless of duration after treatment. Sixteen studies have analysed "periapical health," and 11 revealed pulpal status had no significant influence. Meta-analyses revealed the influence was not significant if preoperative periapical radiolucency was absent (RR: 0.95; 95% CI: 0.90, 1.00; n = 9) but significant if it was present (RR: 1.12; 95% CI: 1.05, 1.19; n = 11). Most studies were classified as "some concerns" (n = 17) to "low" (n = 9) risk of bias RoB.

DISCUSSION

Evidence is limited and only available for three outcomes when comparing the effectiveness of RCTx in permanent teeth with vital pulp versus pulp necrosis. Nevertheless, the quality of available evidence was moderate to high. The "periapical health" data heterogeneity could be explained by preoperative radiolucency, thus RCTx was found more effective for prevention than the resolution of apical periodontitis.

CONCLUSIONS

There was no significant difference in the "tooth survival," "postoperative pain" and "evidence of apical radiolucency" outcomes of RCTx in teeth with vital or necrotic pulps.

REGISTRATION

PROSPERO database (CRD42021260280).

Radiographic Evaluation of the Gap between Cemented Post and Remaining Gutta-Percha in Endodontically Treated Teeth Performed by Undergraduate Students: A Retrospective Cross-Sectional Study

The coronal seal in root canal-treated teeth may be compromised depending on the accuracy of post space preparation and post cementation along with remaining gutta-percha. Root canal treatment can be compromised by endotoxins released by the coronal bacteria as a result of microleakage. The study was conducted by undergraduate students to measure the gap between the cemented post and residual gutta-percha. In total, 217 endodontically treated teeth were evaluated with intraoral peri-apical radiographs. Based on the intraoral periapical radiographic examination in the CS-R4 program, Group I had no gap, Group II had a gap of >0 to 2 mm, and Group III had a gap of more than 2 mm between the end of the cemented post and the remaining gutta-percha. In total, 40% (n = 87) of the teeth had no gap, 59% (127) had a gap of >0 to 2 mm, and 1% (n = 3) had a gap of more than 2 mm between the cemented post end and remaining gutta. Chi square test revealed a significant difference in the gap between the post and remaining gutta-percha between males and females students (p < 0.001). In terms of the gap between the cemented post end and the residual gutta-percha, the root canal treated teeth with post and core by undergraduates were clinically acceptable.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

AIM

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

The effect of different irrigation and disinfection methods on post-operative pain in mandibular molars: a randomised clinical trial

BACKGROUND

To examine post-operative pain (PP) after conventional irrigation and sonic activation methods, with and without laser disinfection in mandibular molars.

METHODS

Eighty patients with symptomatic apical periodontitis were included in this randomized clinical study. There were four study groups. In group 1, conventional irrigation only was applied. In group 2, a sonic irrigation activation system (EDDY (VDW, Munich, Germany)), was applied. In groups 3 and 4, irradiation with a 980-nm diode laser was performed, following irrigation with the conventional method and sonic irrigation activation system, respectively. The patients were instructed to record their PP and analgesic intake using a numerical rating scale 8, 24, 48 h and 7 days post-procedure. A chi-square test, Fisher's exact chi-square test and Fisher-Freeman-Halton exact test were used to assess qualitative data. Inter-group and intra-group parameters were assessed using the Kruskal-Wallis test and Wilcoxon's test at a significance level of p < 0.05.

RESULTS

There was no statistically significant difference among the groups in terms of age, sex, pre-operative pain, PP and analgesic intake (p > 0.05).

CONCLUSIONS

The use of sonic irrigation activation system in the final irrigation protocol and irradiation with the 980-nm diode laser did not significantly reduce PP levels and analgesic intake.

A Pilot Feasibility Study to Establish Full Pulpotomy in Mature Permanent Teeth with Symptomatic Irreversible Pulpitis as a Routine Treatment in Mexican Public Healthcare Services

Symptomatic irreversible pulpitis is a common dental disease for which root canal treatment (RCT) has been the standard treatment. However, in many countries, RCT is considered a high-cost treatment that is not covered by public healthcare services; this forces patients to have dental extraction as their only option to relieve pain. In the last decade, several investigations have provided evidence that an alternative treatment known as full pulpotomy (FP) could be an alternative for patients who could not afford the cost of an RCT. Nevertheless, evidence is lacking on the success rate that could be obtained if it is performed in a public dental care clinic (PDCC). The present investigation has two main objectives. To be the first approach of a multicentric feasibility study to find out whether an FP performed by a general practice dentist (GPD) in a PDCC could be suitable and establish its success rate and patient satisfaction. Patients attending a PDCC with symptoms of irreversible pulpitis were invited to participate. FP was performed and followed up at 1, 3, 6, 9, and 12 months. The treatment success was assessed by combining three variables, patient satisfaction, clinical, and radiographic outcomes. Forty-one patients from 17 to 78 years old received the intervention. In total, 97.5% were completely satisfied with the treatment and were considered successful since none of the clinical or radiographic variables were present in any of the follow-ups. An FP performed by a GPD in a PDCC could be suitable as a routine treatment for symptomatic irreversible pulpitis due to the excellent success rate and patient satisfaction.

Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

Radiographic outcome of root canal treatment in dogs: 281 teeth in 204 dogs (2001-2018)

OBJECTIVE

To evaluate the radiographic outcome of root canal treatment (RCT) in dogs and compare outcomes with those reported for a previous study performed at the same institution in 2002.

ANIMALS

204 dogs representing 281 teeth that underwent RCT.

PROCEDURES

The medical record database of a veterinary teaching hospital was searched to identify dogs that underwent RCT between 2001 and 2018. Only dogs that had undergone at least 1 radiographic recheck appointment a minimum of 50 days after RCT were included in the study. Dental radiographs were reviewed. Treatment was considered successful if the periapical periodontal ligament space was within reference limits and preexisting external inflammatory root resorption (EIRR), if present, had stabilized. Treatment was considered to show no evidence of failure (NEF) if preoperative EIRR had stabilized and any preoperative periapical lucency (PAL) remained the same or had decreased in size but had not completely resolved. Treatment was considered to have failed if EIRR or a PAL developed after RCT, if a preoperative PAL increased in size, or if preexisting EIRR progressed.

RESULTS

Follow-up time ranged from 52 to 3,245 days (mean, 437 days). RCT was classified as successful for 199 (71%) teeth, NEF for 71 (25%) teeth, and failed for 11 (4%) teeth.

CONCLUSIONS AND CLINICAL RELEVANCE

Results showed that almost 2 decades after RCT outcome in dogs was first evaluated, during which time numerous advances in dental materials and techniques had been made, the success rate of RCT was virtually unchanged.

Clinical and radiographic outcome of the root canal treatment of infected teeth with associated sinus tract: A retrospective study

This retrospective study evaluated the outcome of the endodontic treatment/retreatment of teeth with intraoral sinus tracts. Seventy-two teeth from 70 individuals were included. One operator treated all teeth over about 20 years. Time for the sinus tract to heal was recorded. Treatment outcome was evaluated after at least 1 year and classified as healed, healing or diseased. The overall healed rate of periradicular lesions was 73.6% (74.1% for treatment and 72.2% for retreatment). In 6 (8.3%) teeth, lesions were healing. Thirteen teeth (18.1%) exhibited persistent disease. In 68/72 (94.4%) cases, the sinus tract healed in less than 1 month. No preoperative/intraoperative variable affected the outcome (P > 0.05). Missing restorations had a negative impact (P < 0.05). Healing of both the sinus tract quickly after treatment and the periradicular lesion later were usually achieved. Closure of the sinus tract in the first month was a good predictor of lesion healing.

Root canal retreatment: a retrospective investigation using regression and data mining methods for the prediction of technical quality and periapical healing

Objectives

This study aimed to investigate patterns and risk factors related to the feasibility of achieving technical quality and periapical healing in root canal non-surgical retreatment, using regression and data mining methods.

Methodology

This retrospective observational study included 321 consecutive patients presenting for root canal retreatment. Patients were treated by graduate students, following standard protocols. Data on medical history, diagnosis, treatment, and follow-up visits variables were collected from physical records and periapical radiographs and transferred to an electronic chart database. Basic statistics were tabulated, and univariate and multivariate analytical methods were used to identify risk factors for technical quality and periapical healing. Decision trees were generated to predict technical quality and periapical healing patterns using the J48 algorithm in the Weka software.

Results

Technical outcome was satisfactory in 65.20%, and we observed periapical healing in 80.50% of the cases. Several factors were related to technical quality, including severity of root curvature and altered root canal morphology (p<0.05). Follow-up periods had a mean of 4.05 years. Periapical lesion area, tooth type, and apical resorption proved to be significantly associated with retreatment failure (p<0.05). Data mining analysis suggested that apical root resorption might prevent satisfactory technical outcomes even in teeth with straight root canals. Also, large periapical lesions and poor root filling quality in primary endodontic treatment might be related to healing failure.

Conclusion

Frequent patterns and factors affecting technical outcomes of endodontic retreatment included root canal morphological features and its alterations resulting from primary endodontic treatment. Healing outcomes were mainly associated with the extent of apical periodontitis pathological damages in dental and periapical tissues. To determine treatment predictability, we suggest patterns including clinical and radiographic features of apical periodontitis and technical quality of primary endodontic treatment.

Insight into the Reaction of Alexidine with Sodium Hypochlorite: A Potential Error in Endodontic Treatment

Therapeutic success in endodontic treatment depends on successful infection control. Alexidine dihydrochloride (ALX) was recently proposed as a potential alternative to 2% chlorhexidine (CHX) as it possesses similar antimicrobial properties, expresses substantivity and does not produce p-chloroaniline (PCA) when mixed with sodium hypochlorite (NaOCl). However, the products released in this reaction have not been described to date. The aim of this study was to identify detected chemical compounds formed in the reaction of ALX and NaOCl with the ultra-high-performance liquid chromatography–mass spectrophotometry (UHPLC-MS) method and assess whether precipitates and PCA are formed in this reaction. Solutions of ALX were mixed with the equivalent volume of 2% and 5.25% (w/v) NaOCl solutions. As control, 2% (w/v) CHX was mixed with 2% and 5.25% (w/v) NaOCl. Samples were subjected to the UHPLC-MS analysis. The mixture of ALX and NaOCl resulted in a yellowish precipitate formation, the amount of which depended on NaOCl concentration. Interaction of ALX and NaOCl resulted in the production of aliphatic amines. No PCA was formed when NaOCl was mixed with ALX. However, for the first time, we identified the possible products of the interaction. The interaction between NaOCl and ALX results in the formation of aliphatic amines; therefore, these compounds should not be mixed during endodontic treatment.

Success of pulpotomy in mature permanent teeth with irreversible pulpitis: A systematic review

The objective of the present systematic review is to evaluate the success of pulpotomy in mature permanent teeth presented with irreversible pulpitis. The following databases were searched: PubMed, Oral and Dentistry Database, Cochrane, and CINAHL plus. We included studies published in the English language only. However, narrative reviews and case reports/series were excluded. The first electronic and hand search yielded a total of 2851 articles. After going through extensive screening and eligibility process, only six articles were finally selected for the review. The follow-up period ranged from 1 to 10 years. Randomized controlled trial compared pulpotomy with the root canal treatment and reported comparable and even better success of the pulpotomy (78% success). All the other studies have also shown better clinical and radiographic success of pulpotomy (68%–100%). Pulpotomy can be considered an alternative option for mature permanent teeth with irreversible pulpitis.

Chamberless Endodontic Access for Treatment of Calcified Anterior Central Incisors

INTRODUCTION

Modern techniques for treating maxillary anterior central incisors with calcified canals emphasize maintaining coronal dentin with small crown access. Alternatively, traditional retrograde surgical procedures are focused on creating an apical seal predominately limited to the remaining resected apical one third of the root canal space. A treatment option for calcified anterior teeth, with avoidance of traditional orthograde access, is presented. Chamberless endodontic access (CEA) to the canal is chosen in this case, leveraging a previous surgical treatment and osseous defect to create straight line canal access.

METHODS

A tooth presenting with a chronic apical abscess and an apparent previous apical surgery was instrumented and obturated using a CEA avoiding the traditional orthograde approach to the root canal system. Straight line approach was achieved retrograde and canal instrumentation was performed using ultrasonic activated U-files. Canal obturation was accomplished with warm vertical condensation technique followed by placement of an apical retroseal.

RESULTS

A successful 52-month outcome demonstrated the viability of CEA facilitating retrograde instrumentation and obturation.

CONCLUSIONS

Use of CEA simultaneously protected the clinical crown and provided a successful clinical outcome. A viable option for treatment of an anterior calcified canal and abscess due to dental trauma, CEA mitigates many of the risks associated with the treatment of calcified root anatomy.

A randomized controlled trial of endodontic treatment using ultrasonic irrigation and laser activated irrigation to evaluate healing in chronic apical periodontitis

Background

Aim of this trial was to evaluate the combined clinical and radiographic success rate of endodontic treatment using passive ultrasonic irrigation (PUI) and laser activated irrigation (LAI) as compared to conventional syringe irrigation.

Material and Methods

Permanent incisors and single rooted premolars were assessed for eligibility and 69 patients were randomly divided into three treatment groups (n=23) by allocation concealment method and irrigation was performed in accordance with the allocated group. Teeth were evaluated clinically and radiographically with CBCT after 6 months and 12 months of the treatment.

Results

A significant difference was observed in the radiographic healing rates among three groups (χ2=12.29, p=0.05). On comparing the final outcome among the three groups (n=19), it was found that 2 (10.5%) cases of group I(Conventional Syringe irrigation), 7 (36.8%) cases of group II (Passive ultrasonic irrigation) and 8 (42.1%) cases of group III(Laser activated irrigation) were healed while under healing category 13 (68.4%) cases of group I, 12 (63.2%) cases of group II and 11 (57.9%) of group III were observed whereas 4 (21.1%) cases were categorised as diseased in group I only.

Conclusions

LAI and PUI can increase the predictability of the endodontic treatment success in cases of chronic apical periodontitis.

Key words:Cone-beam computed tomography, CBCT-PAI, Irrigation, LASER, Radiographic healing, Root canal treatment, Ultrasonic.

Outcome of Root Canal Treatments Provided by Endodontic Postgraduate Students. A Retrospective Study

The aim of this study was to assess the preoperative, intraoperative, and postoperative factors that influenced complete periapical healing in teeth that underwent primary root canal treatment (RCT), in patients treated by postgraduate students in endodontics. Factors were retrieved and compared with the periapical status during the follow-up visit. Healing was considered as the absence of clinical and radiological symptoms. Variables significantly associated by the chi-squared test were included in a logistic regression model (LRM). Preoperative factors associated with healing were: American Society of Anesthesiology (ASA) status (p = 0.01); the absence of preoperative pain (p = 0.04); positive response to pulp tests; when the RCT cause was caries, pain, abscess, or sinus tract; probing depth <4 mm; the absence of mobility; absence or <4 mm periapical lesion (p < 0.01). In the LRM, the factors included were: absence or <4 mm periapical lesion; probing depths <4 mm; RCT caused by caries, pain, abscess, or sinus tract; the tooth was not a bridge abutment. Postoperative factors were: teeth with direct restoration; teeth that did not act as a support for a fixed prosthetic restoration; the favorable condition of the coronal restoration (p < 0.01). In the LRM, only the status of the coronal restoration was included. Preoperative conditions and the adequate fit of the coronal restoration influenced the outcome of RCT.

Survival Rates of Endodontically Treated Teeth After Placement of Definitive Coronal Restoration: 8-Year Retrospective Study

Introduction

Preservation of endodontically treated teeth (ETT) depends upon several patient-related and operator-related factors. The objectives of this study were to assess the effects of different types of coronal restoration and delayed placement on ETT survival.

Methods

Data on dates of root canal treatment (RCT), restoration type, and extraction time of tooth, when applicable, were analyzed for all patients who underwent RCT from 2010 to 2018 at our institution.

Inclusion Criteria

Root canal-treated teeth with complete preoperative and postoperative radiographs; ETT that were restorable and received final permanent coronal restorations; no periodontal disease or crack detected during RCT; and ETT with acceptable RCT quality.

Exclusion Criteria

Patients who did not attend for follow-up, those had incomplete information available about the coronal restoration, and those with periodontally compromised teeth were excluded. ETT that involved any procedural error were also excluded. The teeth were categorized according to whether they underwent definitive coronal restoration 0–14 days, 15–59 days, or 60+ days after RCT. The statistical analysis was performed using SPSS version 25 (IBM Corp., Armonk, NY). The rate of survival of ETT of 8 years was estimated, and the differences between groups were determined after applying Kaplan–Meier statistics and log-rank tests. A multivariate Cox regression test and Wilcoxon (Gehan) statistics were computed to analyze the influence of different variables. A P-value <0.05 was considered as statistically significant.

Results

The type of restoration, opposing dentition, presence of a post, and dentistry training (year 4 or 5 students) showed significant effects on the survival of ETT (P ≤ 0.000). ETT which received crowns was 2.05 times more likely to need extraction than those in which a composite buildup was performed (hazard ratio [HR] 2.05; confidence interval [CI] 1.84–2.29; P ≤ 0.000). All composite buildups were performed within 14 days of completion of RCT. There was a significant correlation between the time of placement of the final coronal restoration and ETT survival (P ≤ 0.000). Extraction of ETT was 25% more likely (HR 0.25; CI 0.231–0.277) when the final coronal restoration was placed 15–59 days after completion of RCT and 73% more likely (HR 0.73; CI 0.655–0.814) when placed after 60 days than when placed at 0–14 days.

Conclusion

Timely placement of the final coronal restoration is found to be the most critical factor affecting the long-term survival of teeth after RCT.

Clinical and Radiographic Assessment of Cases Referred to Endodontic Surgery

Objective

The objective of the study was to assess the quality of root canal fillings of cases referred to endodontic surgery using preoperative radiographs and correlate it with endodontic surgery treatment decision. The objective was also to analyse clinical symptoms and size of periapical lesions on radiographs and correlate them with treatment decisions including non-surgical retreatment, endodontic surgery and extraction.

Materials and Methods

A questionnaire was composed to record the data. Eighty-six patients with 109 teeth, who were referred to endodontic surgery, participated in the research. The quality of root canal filling was assessed according to its homogeneity and filling length on digital radiographs. The data were analyzed using χ2-test and t-test.

Results

Of the teeth referred to endodontic surgery, 97.2% were treated by a general practice dentist, endodontic retreatment was attempted in 20.6%, and root canal filling was homogeneous and within 1 mm from the apex in 21.6%. Endodontic surgery, retreatment, extraction and no treatment were selected in 90.1%, 5.4%, 1.8% and 2.7% of the cases, respectively.

Conclusions

Low percentage of adequate root canal fillings and high percentage of endodontic surgery decisions suggest that there is a need to increase awareness of non-surgical retreatment options.

Long-term Outcomes of Endodontic Treatment Performed with Resilon/Epiphany

INTRODUCTION

Resilon (Resilon Research LLC, Madison, CT) with Epiphany Sealer (Pentron Clinical Technologies, Wallingford, CT) was introduced into the market in 2004 as a new method of root canal obturation. This material as well as the traditionally used gutta-percha with AH Plus sealer (Dentsply Maillefer, Tulsa, OK) were in use over a 9-year span in the University of North Carolina endodontic clinics. Although Resilon was initially thought to create a "monoblock" seal between the material and the canal, in vitro studies later suggested this concept not to be true. The long-term outcome of Resilon using a validated radiographic index and a systematic approach has not been reported. The purpose of this retrospective cohort study was to radiographically evaluate the outcome of Resilon/Epiphany-treated root canals compared with traditional gutta-percha/AH Plus.

METHODS

One hundred twenty-five teeth were radiographically evaluated using the periapical index; 80 were treated with Resilon and 45 with gutta-percha. Age, sex, tooth position, and number of months to follow-up were documented, and a multivariate analysis with odds ratio was performed.

RESULTS

Resilon-treated teeth were 5.3 times more likely to have a periapical index of 3 to 5 at follow-up compared with gutta-percha (P = .009). Teeth presenting with preoperative lesions, regardless of the material used, were also more likely to present with a lesion at follow-up (P = .04).

CONCLUSIONS

Teeth obturated with Resilon were more likely to present with a lesion at follow-up compared with gutta-percha obturated teeth after controlling for the presence of a preoperative lesion and the length to follow-up.

Anatomical analysis of the resected roots of mandibular first molars after failed non-surgical retreatment

Objectives

Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments.

Materials and Methods

This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area.

Results

Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals.

Conclusions

Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

Microbiology of Root Canal Infections

Inflammatory reaction in the periapical tissues is induced by microbial infection in the root canal system. The aim of root canal treatment is to preserve healthy periapical tissues or to provide healing of them in restorable teeth, which have sufficient periodontal support. The amount of microbial cells in the root canal system and their virulence as well as host responses influence on the degree of periapical inflammation and symptoms. Microbial biofilm formation is typically seen on root canal walls but some microbial species are able to invade the dentine tubules to varying depth. In prolonged and complicated infections, or in case of risk of systemic spread of infection, root canal sampling for microbiological diagnostics is recommended. Anaerobic gram-negative rods are commonly isolated organisms in primary infections. In post-treatment disease, the microflora is dominated by facultatively anaerobic gram-positive cocci and rods such as Streptococcus, Enterococcus, Peptostreptococcus and Actinomyces species. Instrumentation, disinfection and interappointment medication in strict aseptic conditions are essential steps for eradication of microbial species from the infected root canal system. During past decades, Enterococcus faecalis and Candida albicans have been commonly associated organisms in treatment-resistant infections. Novel microbial detection methods are giving increasing knowledge about microbial species associated with endodontic infections and their roles in them.

Endodontic Treatment Outcomes

The primary goal of conventional endodontic treatment is prevention and/or elimination of apical periodontitis for both mature permanent teeth and immature teeth with an open apex. Besides these goals, the objectives of endodontic treatment of immature teeth include preservation of pulp vitality and often further root maturation. Robust criteria for outcome assessment are an essential determinant for any measure of treatment success for both mature and immature teeth.

Evaluation of Bacteriological Profile in the Apical Root Segment of the Patients with Primary Apical Periodontitis

INTRODUCTION

Apical periodontitis usually results from bacterial accumulation and contamination occurring in the root-canal system, and extending beyond the apical foramen to involve the periapical tissues. Literature has a paucity of the studies that stress on the division and analysis of the pulp canal segments. The reason for this disparity might be the technique used for collecting the samples from the pulp canals. Hence, we carried out the present study to evaluate the microbial flora in the apical part of the roots with necrotic pulp canals.

MATERIALS AND METHODS

The present study included the assessment of 40 freshly extracted teeth that had necrotized pulpal tissue along with the presence of periapical periodontal lesions. Removal of the soft tissue lesions attached to the root portion of the teeth along with apical periodontal lesions was done with the help of scalpel blade, after rinsing them with a sterile solution of saline. Thorough cleaning of the root surfaces was done with hydrogen peroxide followed by rapid disinfection with the help of sodium hypochlorite at varying concentrations. Sectioning of the root portion of all the specimens with the help of a disk was done perpendicular to the long axis of the teeth at a distance of roughly 5 to 6 mm from the teeth's apicalmost point. Cryotubes were used for transferring the specimens of apical portions containing 1 mL of buffer and were subjected to immediate frozen processing at a temperature of -20°C. A 10 K-type file was used for the initial collection of the samples followed by subsequent incubation of the files and paper pints in the incubation cabinet. Subsequent deoxyribonucleic acid (DNA) extraction from the samples was done following the procedure described by Siqueira et al. Paster et al's modification of the reverse-capture checkerboard assay was used in the present study. Semiquantitative data were used for overcoming the difficulties arising due to obtaining the counts of the polymerase chain reaction (PCR)-based analysis of specimens.

RESULTS

A positive result for the 16S ribosomal ribonucleic acid (rRNA) gene primer was observed only in two examined specimens of all the samples of the apical portion of the root canals in the present study. Negative result was shown by all the control group specimens, which were sterile samples. Presence of bacteria was confirmed by PCR in 38 out of 40 examined specimens. Amount of bacterial taxa, out of these 24 samples, ranged up to 6. Pseudoramibacter alactolyticus, Porphyromonas endodontalis, Dialister oral species, Bacteroidetes species, Streptococcus species, Olsenella uli, Synergistes species, Fusobacterium nucleatum, Parvimonas micra, Treponema denticola, and Filifactor alocis were the specific species detected. Bacteroidetes species was the only species that were detected at levels at or above 10⁵. Heavy bacterial infections were noticed in more than 45% of the cases at the periradicular part of the root canals.

CONCLUSION

Microbial flora of the apical segment of the root with necrotized pulp tissue comprises a vast variety of pathogenic bacteria.

CLINICAL SIGNIFICANCE

For better prognosis of the treatment of such cases, adequate knowledge of the microbial flora of the root, especially the apical portion is necessary.

Periapical healing outcome following single visit endodontic treatment in patients with type 2 diabetes mellitus

BACKGROUND

The prevalence of apical periodontitis in diabetes mellitus patients is high. The altered immunity in diabetes affects the healing process of periapical tissue. Single visit endodontic treatment has shown to increase the periapical healing rate with better patient compliance. Hence the present study aims at evaluating the clinical and radiographic healing outcome of single visit endodontic treatment, in type 2 diabetes mellitus patients with periapical disease.

MATERIAL AND METHODS

Eighty patients with periapical disease were divided into 2 groups of 40 each: Group I, Control subjects and Group II, Type 2 diabetics. Glycosylated hemoglobin levels were assessed preoperatively and at follow up intervals in diabetics. Pre-operative assessment of periapical status was done using CPDR (Clinical periapical diagnosis of root), QLDR (Qualitative radiographic diagnosis of tooth) and QTDR (Quantitative radiographic diagnosis of tooth) criteria. Postoperative healing was evaluated following single-visit endodontic treatment by Strindberg criteria.

RESULTS

Group 2 subjects had chronic and exacerbating lesions with significantly larger lesions (p=0.029). 100 % clinical healing outcome in diabetic group was seen in two months. Group 2 showed 85% success in one year on radiographic evaluation. Poor controlled diabetics showed failure compared to fair and good controlled.

CONCLUSIONS

Type 2 diabetics had chronic and larger sized lesions when compared to control subjects. The periapical lesions in patients with poor diabetic control showed failure. The clinical and radiographic healing outcome of single visit endodontic therapy was delayed in diabetic patients. Key words:Apical periodontitis, diabetes mellitus type 2, endodontics, periapical lesion, strindberg criteria.

Healing outcomes of root canal treatment for C-shaped mandibular second molars: a retrospective analysis

Objectives

This study aimed to evaluate the healing rate of non-surgical endodontic treatment between C-shaped and non-C-shaped mandibular second molars.

Materials and Methods

Clinical records and radiological images of patients who had undergone endodontic treatment on mandibular second molars between 2007 and 2014 were screened. The periapical index scoring system was applied to compare healing outcomes. Information about preoperative and postoperative factors as well as the demographic data of the patients was acquired and evaluated using chi-square and multinomial logistic regression tests.

Results

The total healing rate was 68.4%. Healing rates for the mandibular second molar were 70.9% in C-shaped canals (n = 79) and 66.6% in non-C-shaped ones (n = 117). The difference was not statistically significant.

Conclusions

The presence of a C-shaped canal in the mandibular second molar did not have a significantly negative effect on healing after treatment. Instead, proper pulpal diagnosis and final restoration were indicated as having significantly greater influence on the healing outcomes of C-shaped and non-C-shaped canals, respectively.

A practical approach to evidence-based dentistry: IV: how to use an article about harm

BACKGROUND AND OVERVIEW

Questions regarding harm are common in dental practice. Observational, nonrandomized studies (that is, cohort studies and case-control studies) are the designs used by investigators to answer most of these questions. A critical appraisal of these studies should include an assessment of the risk of bias, the results, and the applicability of the study. The authors provide the concepts and guidelines that dentists can apply to most effectively use articles regarding harm to guide their clinical practice.

PRACTICAL IMPLICATIONS

Dentists who wish to inform their clinical decisions regarding questions of harm can use these guidelines to decide what type of studies to search, define the specific question of interest to search efficiently for these studies, and critically appraise an article about harm.

Comparison of Two Base Materials Regarding Their Effect on Root Canal Treatment Success in Primary Molars with Furcation Lesions

Introduction. The aim of this study was to compare MTA with another base material, IRM, which is generally used on pulpal floor after root canal treatment, regarding their effect on the success of root canal treatment of primary teeth with furcation lesions. Materials and Methods. Fifty primary teeth with furcation lesions were divided into 2 groups. Following root canal treatment, the pulpal floor was coated with MTA in the experimental group and with IRM in the control group. Teeth were followed up considering clinical (pain, pathological mobility, tenderness to percussion and palpation, and any soft tissue pathology and sinus tract) and radiographical (pathological root resorption, reduced size or healing of existing lesion, and absence of new lesions at the interradicular or periapical area) criteria for 18 months. For the statistical analysis, Fisher's exact test and Pearson's chi-square tests were used and a p value of <0.05 was considered to be statistically significant. Results. Although there were no statistically significant differences between two groups in terms of treatment success, lesions healed significantly faster in the MTA group. Conclusion. In primary teeth with furcation lesions, usage of MTA on the pulpal floor following root canal treatment can be a better alternative since it induced faster healing.

Comparative evaluation of canal cleaning ability of various rotary endodontic filesin apical third: A scanning electron microscopic study

BACKGROUND

The purpose of this study was to evaluate the canal cleaning ability of three novel endodontic rotary instruments and compare with ProTaper files as a control in apical third of root canals under scanning electron microscopy (SEM).

MATERIALS AND METHODS

Eighty freshly extracted mandibular premolars were selected according to inclusion criteria. Buccal cusp tips were ground to ensure having a flat coronal reference point with a total tooth length of 16 mm for all samples. Teeth were divided equally into four groups: Group I (ProTaper group), Group II (ProTaper next group), Group III (variable taper group), and Group IV (self-adjusting file [SAF] group). Using SEM, the dentinal surfaces were observed and rated at apical thirds with a magnification of ×1000 for the presence/absence of smear layer and debris. Descriptive analysis was performed, and analysis of variance with Bonferroni post hoc test was carried out for comparison between the groups, at a significance level of 0.05.

RESULTS

There was statistically significant difference between Group II and Group IV for debris (P = 0.047) and smear layer (P = 0.037).

CONCLUSION

In apical third of root canal, SAF showed statistically significant canal cleaning ability due to combined effect of continuous streaming irrigation with effectively replacing the irrigant from the apical portion of the root canal, irrigants activation through the creation of turbulence, and its self-adapting design to root canal anatomy with a scrubbing motion on the canal walls.

A clinical study on single-visit root canal retreatments on consecutive 173 patients: frequency of periapical complications and clinical success rate

OBJECTIVES

This study assessed the outcome measures of single-visit root canal retreatments and frequency of periapical complications considering preoperative, intraoperative and postoperative factors.

MATERIALS AND METHODS

Between November 2011 and December 2012, in 173 patients, a total of 234 endodontically treated teeth were retreated in a single appointment by one experienced endodontist. Five teeth were extracted and 119 teeth were lost to follow-up yielding to 110 teeth (47 %) to be examined by two calibrated examiners for the outcome of healing (periapical index score-PAI ≤2; no signs or symptoms) or non-healing (presence of apical periodontitis-PAI >2; signs or symptoms). Preoperative, intraoperative and postoperative factors were evaluated for their association with the outcome. Data were analysed using Fisher's exact and Fisher-Freeman Halton tests for bivariate analysis to identify potential outcome predictors. Logistic regression models were used for multivariate analysis to determine significant outcome predictors.

RESULTS

Mean observation time was 29 months. Follow-up assessment revealed 100 teeth (90.9 %) as healed and 10 teeth (9.1 %) non-healed. Age, gender, tooth type and preoperative (pain, periodontal defects, root filling density and length), intraoperative (sealer extrusion) and postoperative (type of coronal restorations) factors did not significantly affect the outcome (p > 0.05). Preoperative periradicular lesions with diameters less than 5 mm presented significantly better outcome than larger lesions (p < 0.05; odds ratio (OD) 6; 95 % CI 1.45-24.85). Logistic regression model showed an increased risk of non-healing for the parameter of preoperative periradicular lesions with diameters larger than 5 mm (OD 6.42; 95 % CI 1.51-27.27).

CONCLUSIONS

Single-appointment root canal retreatments presented a favourable success rate. Only preoperative lesion size had a significant effect on the outcome where the lesions smaller than 5 mm performed significantly better healing.

CLINICAL RELEVANCE

Single-appointment root canal retreatments could be considered as a viable treatment option for orthograde retreatment cases with periradicular lesion size smaller than 5 mm.

Healing after regenerative procedures with and without pulpal infection

Regenerative endodontic procedures for immature teeth with pulp necrosis have gained a lot of interest. Basic scientific research has documented the potential for dental pulp regeneration in preclinical studies. A number of case reports and case series have shown the control of clinical infection and increases in thickness and length of the roots. Preoperative infection is an important factor that predicts outcome in nonsurgical endodontic treatment in mature teeth and seems to also be an important determinant of outcome in treating immature teeth. However, antimicrobial strategies for the immature tooth in which pulp regeneration is contemplated are different from those used in mature cases. This is because of the interest in disinfecting the root canal to a higher level to promote tissue growth without disrupting the bioactive potential of root dentin and the viability of stem cells from which the regenerated tissue would develop. This review addresses the factors involved in making clinical decisions in this area in light of the information available on the microbiology of endodontic infections, the efficacy to antimicrobial strategies, and the outcomes of regenerative and alternative procedures.

Single Versus Multi-visit Endodontic Treatment of Teeth with Apical Periodontitis: An in vivo Study with 1-year Evaluation

Background:

Apical periodontitis (AP) is one of the most prevalent diseases of the teeth. Treatment of AP is based on the removal of the cause, i.e., bacteria from the root canals. Achievement of adequate bacterial eradication in one appointment treatment remains a controversy.

Aim:

This prospective study was conducted with the objective to compare the periapical healing of teeth with AP treated in (a) single visit versus (b) two visits, either with or without Vitapex as an intracanal medicament.

Subjects and Methods:

Patients were selected randomly from the Department of Conservative Dentistry and Endodontics. Forty-three patients (81 teeth) met the inclusion criteria, i.e., AP (both symptomatic and asymptomatic) visible radiographically size ≥2 mm × 2 mm, not suffering from any immune-compromising disease, age between 16 and 65 years and tooth not accessed previously. Patients were randomly divided into three groups, i.e., single-visit group (Group 1), multi-visit group without any intracanal medicament (Group 2), and multi-visit group with Vitapex as interim intracanal medicament (Group 3). Comparison was done radiographically using periapical index (PAI). The primary outcome measure was the change in periapical radiolucency after 1 year assessed by PAI scores. The Mann-Whitney U-test was used to evaluate differences between groups at baseline (immediate postoperative) and at the 12-month follow-up evaluation. Change in PAI score for each group from baseline to 12-month follow-up evaluation was tested with the Wilcoxon signed rank test. The secondary outcome measures, proportion of teeth in each group that could be considered improved (decreased PAI score) or healed (PAI <2), were assessed with the Chi-square test.

Results:

No statistically significant difference in periapical healing was found between three groups.

Conclusion:

After 1-year evaluation, no difference in periapical healing was found between single-visit treatment and multi-visit treatment groups with the given sample size.

Characterization of successful root canal treatment

Knowing the outcome of root canal treatment (RCT) is determinant to substantiate the clinical decision making process, especially when RCT is weighed against the extraction of natural teeth or replacement by prosthetic elements. The ideal scenario in all clinical situations should combine healing/prevention of disease (apical periodontitis) and the functional retention of the tooth. Understanding the risk factors associated with endodontic failure is a key factor to increase the chances of success. The logical action is to reverse the existing disease, which requires intervention to neutralize the bacterial invasion and disrupt the bacterial biofilm within the complex anatomy. Success is more predictable when the immune host defenses are favorable. However, success has different meanings to the dentist, to the patient and to the tooth itself. The life of an endodontically treated tooth depends on the accuracy of the diagnosis and planning, excellence of disinfection, instrumentation and filling procedures (antimicrobial strategies, root canal shaping and coronal and apical seal) and finally the rehabilitation management. The interpretation of constant or intermittent pain and/or discomfort associated with apical periodontitis (AP) in endodontically treated tooth may be suggestive of endodontic failure. The success features of RCT, namely absence of pain, regression of AP, tight seal of canal and coronal spaces, and recovery of tooth function, must be reevaluated over time. In case of doubt between success and failure, cone beam computed tomography (CBCT) could be indicated for detection and precise localization of AP. The possibility of map reading on CBCT images characterizes the real multidimensional structure, providing accurate information on the presence, absence or regression of AP. The survival of an endodontically treated tooth implies understanding the biological and mechanical outcomes as multifactorial events over the individual's life span. The objective of this review of literature is to discuss relevant factors associated with patient's health, tooth and dentist that could account for a successful RCT.

Retreatment Predictions in Odontology by means of CBR Systems

The field of odontology requires an appropriate adjustment of treatments according to the circumstances of each patient. A follow-up treatment for a patient experiencing problems from a previous procedure such as endodontic therapy, for example, may not necessarily preclude the possibility of extraction. It is therefore necessary to investigate new solutions aimed at analyzing data and, with regard to the given values, determine whether dental retreatment is required. In this work, we present a decision support system which applies the case-based reasoning (CBR) paradigm, specifically designed to predict the practicality of performing or not performing a retreatment. Thus, the system uses previous experiences to provide new predictions, which is completely innovative in the field of odontology. The proposed prediction technique includes an innovative combination of methods that minimizes false negatives to the greatest possible extent. False negatives refer to a prediction favoring a retreatment when in fact it would be ineffective. The combination of methods is performed by applying an optimization problem to reduce incorrect classifications and takes into account different parameters, such as precision, recall, and statistical probabilities. The proposed system was tested in a real environment and the results obtained are promising.

Treatment outcomes of single-visit versus multiple-visit non-surgical endodontic therapy: a randomised clinical trial

BACKGROUND

Clincians have been providing single-visit and multiple-visit endodontic treatments for their patients. This study aims to compare the success rate, prevalence of postoperative pain and chairside time of single-visit and multiple-visit endodontic treatments.

METHOD

Patients who required primary endodontic treatment in a university dental clinic were randomly allocated to two general dentists for single-visit or multiple-visit treatments using the same materials and procedures. Ni-Ti rotary files were used to prepare the root canals, which were subsequently obturated with a core-carrier technique. The chairside time was recorded. The treated teeth were followed up every 6 months on clinically signs and symptoms including pain, tenderness to percussion, sinus tract, mobility and abscess. Periapical radiographs were taken to assess periapical pathology. Successful treatments were neither clinical signs/symptoms noted nor radiographic periapical pathology found postoperatively.

RESULTS

A total of 220 teeth from patients aged 46.4 ± 14.1 were followed up for at least 18 months. The mean (±SD) follow-up period was 29.4 ± 9.3 months. The success rates of single-visit and multiple-visit treatments were 88.9 and 87.4 %, respectively (p = 0.729, effect size odds ratio = 1.156). Maxillary teeth had odds ratios of 3.16 (95 % CI: 1.33 to 7.46; p = 0.009) and absence of preoperative apical periodontitis had odds ratios of 4.35 (95 % CI: 1.43 to 13.24; p = 0.010) were identified from logistic regression as having a higher success rate. The average chairside times of single-visit and multiple-visit treatments were 62.0 and 92.9 min, respectively (mean difference = -30.9, 95 % CI: -39.4 to -22.4, p < 0.001, effect size odds ratio = -0.996). Single-visit and multiple-visit treatment had no significant difference in the prevalence of postoperative pain within 7 days (21 and 12 %, p = 0.055, effect size odds ratio = 2.061) and after at least 18 months (0.9 and 1.0 %, p > 0.999, effect size odds ratio = 0.879).

CONCLUSIONS

The success rate and prevalence of postoperative pain of single-visit or multiple-visit treatment had no significant difference. The chairside time for single-visit treatment was shorter than multiple-visit treatment.

TRIAL REGISTRATION

Clinical Trials (WHO) ChiCTR-IOR-15006117 registered on 20 March 2015.

Effect of education intervention on the quality and long-term outcomes of root canal treatment in general practice

AIM

To compare the technical quality and long-term outcomes of root canal treatment by general practitioners of a Swedish Public Dental Service, before and after an endodontic education including Ni-Ti rotary technique (NiTiR).

METHODOLOGY

A random sample was compiled, comprising one root filled tooth from each of 830 patients, treated by 69 general practitioners participating in the education: 414 teeth root filled in 2002, pre-education, using primarily stainless steel instrumentation and filling by lateral compaction, and 416 teeth root filled post-education (2005), using mainly NiTiR and single-cone obturation. Follow-up radiographs taken in 2009 were evaluated alongside immediate post-filling radiographs from 2002 to 2005. The density and length of the root fillings were registered. Periapical status was assessed by the Periapical Index (PAI), using two definitions of disease: apical periodontitis (AP) (PAI 3 + 4 + 5) and definite AP (PAI 4 + 5). Tooth survival was registered. Root fillings pre- and post-education were compared using chi-square and Fisher's exact tests. Crude extraction rates per 100 years were calculated for comparison of tooth survival. Explanatory variables (type of tooth, root filling quality, periapical status, marginal bone loss, type and quality of coronal restoration) in relation to the dependent variable (AP at follow-up) were analysed by multivariable logistic regression.

RESULTS

Follow-up data were available for 229 (55%) of teeth treated pre- and 288 (69%) treated post-education: both tooth survival (P < 0.001) and root filling quality were significantly higher (P < 0.001) in the latter. However, there was no corresponding improvement in periapical status. Both pre- and post-education, root fillings with definite AP on completion of treatment had significantly higher odds of AP or definite AP at follow-up. For teeth treated post-education, inadequate root filling quality was significantly associated with AP at follow-up.

CONCLUSIONS

Despite a higher tooth survival rate and a significant improvement in technical quality of root fillings after the education, there was no corresponding improvement in periapical status.