The effect of an intraorifice barrier and base under coronal restorations on the healing of apical periodontitis: a randomized controlled trial

A fluorescence-based method to reaccess root canals in endodontically treated teeth: a MicroCT tridimensional assessment

AIM

To evaluate the volume of dentin removal and volume of remnants of restorative material after removal of aesthetical restorative coronal set and cervical barrier in endodontically treated mandibular molars with aid of different magnification methods, using 3D MicroCT morphometric analysis.

METHODS

A sample of 30 mandibular first molars (n=30) were used. All teeth were endodontic treated, and the specimens were initially scanned in MicroCT and reconstructed. The molars were filled by single cone technique, and immediately the material at the initial 2 mm cervical level were removed. Cervical barriers were confected using ionomer glass cement added with fluorescein 0.1%, filling the 2 mm at the cervical level of the canals and 2 additional millimeters as base. Coronal restoration set was performed using aesthetical resin composites. Simulated tooth aging process was performed with 20,000 thermocycling cycles. The sample was distributed in three groups (n=10) for the removal of the restoration set and cervical barrier with diamond burs based on the magnification aid: No magnification aid (naked-eye); Operative microscope aid; REVEAL™ device aid. After removal, final 3D MicroCT scanning and reconstruction were conducted with same parameters as the initial, and superposition of final and initial scanning was done. Morphometric analysis was conducted using CTAn to assess volume of remnant restorative material (mm³), volume of dentin removal (mm³), and the direction and site of dentin removal. Data were analyzed using One-Way ANOVA (p<0.05).

RESULTS

REVEAL™ group showed better results regarding the volume of remnant material (3.17 ± 1.65) and the percentage of dentin removal (2.56 ± 1.34). Microscope group showed no statistical difference to the REVEAL™ group of dentin removal (3.30 ± 1.48), and was statistically similar to the naked eye group in volume of remnant material (9.63 ± 4.33). Naked eye group showed the worst results for volume of remnant material (7.60 ± 2.68) and percentage of dentin removal (6.60 ± 3.70).

CONCLUSION

The use of fluorescence associated with magnification was the method that presented the best results, with lower percentages of dentin removal and smaller volumes of remaining restorative material. This is an innovative technology in Endodontics that shows potential to overdue the challenge of re-accessing root canals in the context of endodontic retreatment.

Prevalence of Teaching Apical Patency and Various Instrumentation and Obturation Techniques in United States Dental Schools: Two Decades Later

INTRODUCTION

Maintaining apical patency has been advocated to minimize canal transportation, ledge formation, and loss of working length, despite increasing debris extrusion. A previous study in 1997 by Cailleteau and Mullaney reported 50% of United States dental schools taught patency. This present study aimed to evaluate recent trends in endodontic education in United States dental schools, in relation to the prevalence of maintaining apical patency and examining the primary methods of working length determination, instrumentation, obturation, and temporization.

METHODS

A survey of 20 questions was distributed to 65 schools via e-mail and was available from July 2021 to September 2021.

RESULTS

Seventy-three percent of the 46 responding schools reported that they teach patency, with 8% of this number reporting that they do so exclusively to endodontic residents. Notably, a significantly lower number of schools reported teaching patency exclusively to endodontic students compared with the Cailleteau and Mullaney study despite a significantly higher percentage of schools teaching patency overall. The most common method used to determine working length was an electronic apex locator at the 0.5 reading. Vortex Blue was the most commonly used file system used by both predoctoral and postdoctoral programs. Lateral condensation was the primary obturation technique taught in predoctoral programs, whereas warm vertical condensation was the primary obturation technique in postdoctoral programs. The study also found that 57% of schools reported using intraorifice barriers, and the most common temporary filling was glass ionomer.

CONCLUSIONS

A greater portion of schools teaches patency compared with the previous study in 1997. The data collected in this survey may serve as a baseline for similar studies in the future regarding changes in endodontic education over time.

Biological considerations of dental materials as orifice barriers for restoring root-filled teeth

There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.

Factors that affect the outcomes of root canal treatment and retreatment-A reframing of the principles

This paper undertakes a broad and comprehensive synthesis of relevant clinical, biological, biomechanical, technical and healthcare services data to understand the factors affecting outcomes of periapical healing after root canal (re)treatment. The medical and dental evidence-based era (1980-present) is contextualized with the earlier evidence drive in endodontics (1911-1940) triggered by the focal infection era. The current evidence-based approach has a sharper focus on evidence quality and derivation of practice guidelines. Contrary views question whether guideline-driven, or expertise-development-driven endeavours would best serve outcome improvement in society. The endodontic discipline functions in a broad healthcare framework and sustains industrial, economic and trend pressures that may be deemed to influence outcomes. The nature of root canal treatment and the challenges in determining the factors that affect its outcomes is discussed. The factors potentially affecting periapical healing after root canal treatment are classified into pre-operative, intra-operative and postoperative groups. These categories subsume multiple elements with interactive influences, creating a complex picture, further confounded by some apparently surprising, counter-intuitive and contradictory findings. The technical versus biological conundrum in root canal treatment continues to cause cognitive dissonance. However, due reflection and cross-discipline-synthesis resolve the apparent data conflicts into a very simple, consistent and plausible picture of how root canal treatment works and the key factors that affect periapical healing. Root canal retreatment is considered mainly in the context of its differences from primary treatment as the majority of factors influencing outcomes are common to both. The exceptional difference is that retreatments have a proportionately reduced probability of healing by virtue of compromised apical root canal ramification access or modified host/infection interactions. Root canal (re)treatment outcomes are dominantly influenced by the nature of prior dynamic host/infection interaction (pre-operative patient factors) and how the direction of this dynamic is influenced by two factors: (1) the active efficacy of the operators' root canal treatment protocol to sustain a microbial ecological shift (intra-operative treatment factors) and dampen periapical inflammation; and (2) the passive ability of the functional tooth (and its restoration margin) to maintain its integrity to resist infection reversal (postoperative restorative factors).

The differences of microleakage smart dentin replacement, glass ionomer cement and a flowable resin composite as orifice barrier in root canal treated

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Periapical and Endodontic Status of Patients with Inflammatory Bowel Disease: Age- and Sex- matched Case-control Study

AIM

Crohn's disease (CD) and ulcerative colitis (UC) are two chronic recurrent inflammatory processes of the gastrointestinal tract, grouped under the name Inflammatory Bowel Disease (IBD), causing clinical episodes of intestinal inflammation. The aim of this study was to investigate the possible association between IBD and the prevalence of apical periodontitis and root canal treatment.

METHODOLOGY

A case-control study design matched to age and sex was used. The study group (SG) included 28 patients with IBD (13 with CD, 15 with UC). Another 28 healthy subjects, without IBD and age- and sex- matched, were included in the control group (CG). Radiographic records were analyzed and apical periodontitis (AP) was diagnosed as radiolucent periapical lesions (RPLs), using the periapical index score (PAI). Student's t test, χ² test and multivariate logistic regression were used in the statistical analysis.

RESULTS

In the CG, only 17 subjects (61%) had at least one tooth with AP, while in the SG group they were 23 patients (82%) (OR = 2.98; CI 95% = 0.87 - 10.87; p = 0.08). The number of subjects with one or more root filled teeth (RFT) in the CG was 14 (50%), while in the SG they were 22 (79%) (OR = 3.67; 95% CI = 1.14 - 11.79; p = 0.026). At least one RFT with AP was evident in 3 subjects (10.7%) in the control group, while in the study group 15 patients (53.6%) showed RFT with AP (OR = 9.60; 95% CI = 2.35 - 39.35; p = 0.001). In the multivariate logistic regression analysis, only endodontic status was found to be associated with IBD (OR = 1.86; 95% CI = 1.24 - 2.80; p = 0.003).

CONCLUSION

IBD, ulcerative colitis and Crohn´s disease, is associated with higher prevalence of RFT and higher percentage of RFT with periapical lesions. Dentists should consider these findings when caring for IBD patients by monitoring the evolution of periapical lesions of endodontically treated teeth.

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).

Comparative evaluation of complete and partial pulpotomy in mature permanent teeth with symptomatic irreversible pulpitis: A randomized clinical trial

AIM

The study aimed to compare the outcome of complete pulpotomy (CP) and partial pulpotomy (PP) techniques when utilised for the management of mature permanent teeth with carious pulpal exposure and symptomatic irreversible pulpitis (SIP).

METHODOLOGY

The study protocol was registered with ClinicalTrials.gov (NCT04397315). One hundred and six permanent mandibular molars with carious pulpal exposure and clinical diagnosis of SIP with periapical index ≤2, from patients aged between 18 and 40 years were randomly allocated in equal proportion to either CP or PP group. Allocated procedures were performed using standardised protocols. The allocated procedure was abandoned in cases where pulpal bleeding could not be controlled within 6 min using cotton pellets soaked in 3% sodium hypochlorite. MTA was used as a pulpotomy agent and teeth were restored using a base of glass ionomer followed by composite restoration. The pain was recorded by the patient preoperatively before administration of local anaesthesia and postoperatively every 24 h for 1 week using visual analogue scale. Success was analysed at 12 months based on clinical and radiographic examination. Mann-Whitney U test was used to compare age, pain scores and mean analgesic consumption between the groups. Categorical data were analysed using chi-square test. Fisher's exact test was used to assess the clinical and radiographic success and incidence of pain. Kaplan-Meier analysis was used to assess the survival of teeth. A p-value <.05 was considered as statistically significant.

RESULTS

One hundred and one patients were analysed at follow up. Higher success was observed in CP (89.8%) in comparison to PP group (80.8%), but the difference was non-significant statistically (p = .202). Although no significant difference was observed in pain incidence between the groups at 24 h (p = .496), a significant difference in pain intensities was observed between groups at all the tested time intervals, with lower values reported in CP group (p < .05).

CONCLUSIONS

Both CP and PP resulted in favourable outcomes in the management of cariously exposed permanent teeth with signs indicative of SIP. Given the more conservative nature of PP, it may be attempted first before proceeding to CP in such cases.

Effect of an Intraorifice Barrier on Endodontically Treated Teeth: A Systematic Review and Meta-Analysis of In Vitro Studies

The main cause of unsuccess in endodontically treated teeth (ETT) is due to bacterial recontamination. The placement of an intraorifice barrier (IOB) has been proposed for preventing this event in cases that the restoration is in an inadequate condition, enhancing the possibilities for predictable long-term success in endodontic therapy. Objectives. To evaluate through a systematic review and meta-analysis if it would be necessary to place an IOB in ETT. Materials and Methods. The present review is in accordance with the PRISMA 2020 Statement and is registered in the Open Science Framework. Two blinded reviewers carried out a comprehensive search in four databases up to July 10^th, 2021: MEDLINE, Scopus, Embase, and Web of Science. Eligible studies were the ones which evaluated the use of an IOB in ETT in reducing microleakage with any material of choice and with any methods employed. Only in vitro studies published in English were included. Results. A total of thirty in vitro studies were included in the qualitative synthesis, and seven of those were included in the quantitative analyses evaluating the following materials: bioceramic cement, glass-ionomer cement (GIC), and resin-based composite (RBC). Most of the included studies placed an IOB at a 3 mm depth. Reduction in microleakage was observed when an IOB was placed, regardless of the material employed (p ≤ 0.01). Among the materials, GIC and RBC performed similarly (p > 0.05), with the bioceramic subgroup being statistically superior to the GIC subgroup (p ≤ 0.05). Conclusions. Although well-designed randomized clinical trials are required, the placement of an intraorifice barrier can significantly reduce microleakage in endodontically treated teeth, and the use of bioceramics as IOB seems to be the best available material for this purpose.

Can Probiotics Emerge as Effective Therapeutic Agents in Apical Periodontitis? A Review

Apical periodontitis (AP) is a biofilm-associated disease initiated by the invasion of dental pulp by microorganisms from the oral cavity. Eradication of intracanal microbial infection is an important goal of endodontic treatment, and this is typically accomplished by mechanical instrumentation and application of sodium hypochlorite and chlorhexidine. However, these agents are tissue-irritating at higher concentrations and cytotoxic. Certain probiotics have been found effective in controlling marginal periodontitis, as evidenced by reduction of pathogenic bacterial loads, gains in clinical attachment levels, and reduced bleeding on probing. In vitro studies have shown inhibitory activity of some probiotics against endodontic pathogens. Similarly, in vivo studies in rats have demonstrated a positive immuno-modulatory role of probiotics in AP, as manifested by decreased levels of proinflammatory markers and increased levels of anti-inflammatory markers. A role for probiotics in effecting a reduction of bone resorption has also been reported. This review provides an outline of current research into the probiotic management of AP, with a focus on understanding the mechanisms of their direct antagonistic activity against target pathogens and of their beneficial modulation of the immune system.

Apical periodontitis and glycemic control in type 2 diabetic patients: Cross-sectional study

BACKGROUND

The objective of this study was to analyze the possible relationship between the glycemic control and the prevalence of apical periodontitis in type 2 diabetic patients. The null hypothesis was that apical periodontitis is not associated with glycemic control.

MATERIAL AND METHODS

In a cross-sectional design, the radiographic records of 216 type 2 diabetic patients (65.0 ± 10.7 years), 117 men (54.2%) and women (45.8%), were examined. Glycated hemoglobin (HbA1c) was used to assess glycemic control, considering an HbA1c level < 6.5% as well-controlled diabetes. Apical periodontitis was diagnosed as radiolucent periapical lesions using the periapical index score. The Student t test, chi-square test, and logistic regression analysis were used in the statistical analysis.

RESULTS

The average HbA1c value was 7.0 ± 2.2%. Forty seven (21.8%) had HbA1c levels under 6.5% (mean ± SD = 6.0 ± 2.2%), being considered well-controlled patients, and 169 (78.2%) had an HbA1c level ≥ 6.5% (mean ± SD = 7.8 ± 2.24%), being considered poor controlled patients. Forty four per cent of diabetics had apical periodontitis, 12.5% had root-filled teeth, and 52.3% had root filled teeth with radiolucent periapical lesions. No significant differences were observed in any of these three variables between patients with good or poor glycemic control. In the multivariate logistic regression analysis the presence of radiolucent periapical lesions in at least one tooth did not correlate significantly with HbA1c levels (OR = 1.4; 95% C.I. = 0.70 - 3.09; p = 0.31).

CONCLUSIONS

The results reveal no association of glycemic control with the prevalence of apical periodontitis or root canal treatment in diabetic patients. Key words:Apical periodontitis, diabetes mellitus, endodontic medicine, glycated haemoglobin.