Clinical and Radiographic Failure of Non-surgical Endodontic Treatment and Retreatment Using Single-cone Technique with Calcium Silicate-Based Sealers: A Systematic Review and Meta-Analysis.

INTRODUCTION: This systematic review and meta-analysis aimed to evaluate the clinical and radiographic failure of non-surgical endodontic treatment and retreatment for mature permanent teeth with or without apical periodontitis using the single-cone (SC) obturation technique with calcium silicate-based bio-ceramic (CSBC) sealers and to compare these failure rates to other sealer materials and obturation techniques. METHODS: A comprehensive search was conducted using MEDLINE (PubMed), Embase, Cochrane Library, Scopus, Web of Science, and gray literature up to March 2023. Two reviewers assessed the eligibility of the included studies. Eligible studies were critically appraised for risk of bias and quality of evidence. Subsequently, a meta-analysis of pooled data was conducted utilizing the RevMan software (P< 0.05) to evaluate the failure rate of non-surgical root canal therapy using CSBC sealers and SC obturation procedures. Separately, another analysis was conducted to compare those results with the outcome of non-surgical root canal therapy using alternative obturation materials and methods. RESULTS: 5 studies were included. The pooled failure rate for non-surgical endodontic treatment and retreatment combined using CSBC sealers and SC obturation technique was 6.8% [95% confidence interval (CI)= (3%-12%), I2 = 46%]. A second analysis was conducted on the three included clinical trials to compare the outcomes of the intervention (CSBC sealers and SC obturation technique) and control groups (other sealers and other obturation techniques). This analysis found no significant difference between the two groups regarding clinical and radiographic failure of endodontic treatment and retreatment [Risk ratio=0.71, 95% CI = (0.33,1.51), I2 = 0]. This difference was also not statistically significant when the failure rate of primary root canal treatment and retreatment were separately analyzed [Combined Risk ratio of primary root canal treatment=0.94, 95% CI = (0.46,1.93), I2= 0%; Combined Risk ratio of retreatment=0.21, 95% CI = (0.001, 75.46), I2= 0%]. CONCLUSIONS: The overall results of this systematic review and meta-analysis demonstrate that the SC obturation technique with CSBC sealer provides similar results compared to other obturation materials and techniques in facilitating the healing of apical periodontitis.

The Effect of Master Apical Preparation Size on Healing Outcomes in Endodontic Treatment: A Systematic Review and Meta-Analysis.

INTRODUCTION: The aim of this systematic review was to assess the existing literature and examine whether or not the size of apical enlargement during mechanical preparation affects the outcome of treatment in patients undergoing nonsurgical root canal therapy (NSRCT). METHODS: MEDLINE (PubMed), Embase, Cochrane Library, and gray literature were searched (January 2000-May 2023). Study selection and data extraction were performed in duplicate. Eligible studies were critically appraised for risk of bias and quality of evidence and were meta-analyzed to estimate the treatment effects. RESULTS: Two studies were included in the meta-analysis. The overall pooled success rate was 75.8%. The success rates of treatment with an apical size ≥ 30 and < 30 were 80.9% and 52.9%, respectively. Cases with an apical size ≥ 30 demonstrated significantly more favorable results (RR = 0.63, 95% Confidence Interval 0.46-0.79, P < .05). The overall quality of evidence was low. CONCLUSIONS: With a low certainty of evidence, master apical preparation size ≥ 30 may result in an increased healing outcome in terms of clinical and radiographic evaluations.

Cell-Based Regenerative Endodontics for the Treatment of Irreversible Pulpitis: AnIn VivoInvestigation.

INTRODUCTION: This study aims to investigate the ability of umbilical cord mesenchymal stem cells (UC-MSC) to enhance the regeneration of pulp-dentin complex in immature permanent teeth with irreversible pulpitis. METHODS: A total of 32 mandibular premolar teeth with immature apices in 5 dogs were used in this in-vivo randomized controlled trial (RCT). Eight healthy teeth without pre-existing pathosis served as the positive control samples and received no treatment, while in another 8 teeth, the pulp was completely extirpated (negative control). Class V cavities were prepared to induce inflammation in the remaining 16 teeth (groups 3 and 4) and the pulp was extirpated 2-4 mm short of the radiographic apex. Of the 16, the 8 teeth in group 4 received 1 mL of cord blood stem cells with a hydrogel scaffold. Blood clots were covered with mineral trioxide aggregates at the cementoenamel junction in the experimental groups, and teeth were filled with RMGI and composite. Three months later, block sections were removed for histologic evaluations for the evaluation of postoperative apical closure, degree of inflammation, and presence of normal pulp tissue. The data were statistically analyzed with the chi-square test (P < .05). RESULTS: All teeth with complete pulp extirpation demonstrated pulpal necrosis with no postoperative closure of their apices, while apical closure was seen in all the teeth in the remaining groups. There was a statistically significant (P < .001) difference in the presence of inflammation and normal pulp tissue between the experimental groups. The teeth in group 3 showed normal pulp tissue extending to the level of MTA, but there was inflammation within the canal space. In contrast, the teeth in the UC-MSC group demonstrated organized, normal pulp tissue with no inflammation. CONCLUSION: Based on these results, the regeneration of the pulp-dentin complex is possible with no inflammation when UC-MSCs are used and 2-4 mm of the apical pulp remains intact in immature teeth with irreversible pulpitis.

Expression of Selected Inflammatory Mediators with Different Clinical Characteristics of Pulpal Inflammation.

INTRODUCTION: Accurately diagnosing the state of dental pulp is crucial when addressing tooth pain to determine the best treatment approach. This study aimed to investigate the concentration of inflammatory mediators in the dental pulp of mature teeth that have been exposed via caries but show no signs of apical periodontitis. METHODS: Samples of pulpal blood from adults with mature teeth responsive to pulp testing and have carious pulp exposures were obtained. These samples were analyzed for 12 inflammatory cytokines and other inflammatory proteins using the Luminex assay platform. Clinical factors were correlated with cytokine levels, and statistical analysis was performed to evaluate the impact of these factors on cytokine expression. RESULTS: Of the 36 patients that were included, 44.44% took pain medications, 33.33% had prolonged pulpal bleeding, 41.67% felt spontaneous pain, and 72.22% were diagnosed with symptomatic irreversible pulpitis. Significant correlations existed between presenting pain scores and levels of interleukin (IL)-1α, IL-6, and IL-8 (P < .05). Factors like analgesic medication intake, pain to percussion, pain to thermal testing, spontaneous pain, and nocturnal pain were significantly associated with higher levels of specific inflammatory proteins. No significant associations were observed with pain to palpation, bleeding time, or pulpal diagnosis. CONCLUSIONS: Inflammatory proteins, including cytokine levels may play a critical role in characterizing pulpal inflammation. Future studies should investigate the role of these potential biomarkers in determining the diagnosis of pulpitis and the prognosis of vital pulp therapy.

Push-out bond strength of Resilon/Epiphany self-etch and gutta-percha/AH26 after different irrigation protocols.

OBJECTIVE: The purpose of this study was to compare the bond strength of Resilon/Epiphany self-etch (SE) and gutta-percha/AH26 after different irrigation protocols. STUDY DESIGN: Extracted single-rooted human teeth were divided into 4 groups and prepared. According to irrigation protocols, groups were: 5.25% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA) (groups 1 and 2); and 1.3% NaOCl followed by MTAD (a mixture of tetracycline isomer, an acid, and a detergent) (groups 3 and 4). The root canals were obturated with either gutta-percha/AH26 (groups 1 and 3) or Resilon/Epiphany SE (groups 2 and 4). Push-out bond strength and failure modes were determined. RESULTS: Gutta-percha/AH26 showed significantly higher bond strength than Resilon/Epiphany SE. The group with 5.25% NaOCl + EDTA and gutta-percha had a significantly higher bond strength than all of the other groups (P < .05); 1.3% NaOCl + MTAD with gutta-percha showed significantly higher bond strength than 5.25% NaOCl + EDTA with Resilon and 1.3% NaOCl + MTAD with Resilon. There was no significant difference between the bond strengths of the Resilon groups (P > .05). The failure mode for all of the experimental groups was mainly adhesive. CONCLUSIONS: Irrigation with 5.25% NaOCl + EDTA can be a better conditioner before using gutta-percha/AH26. The bond strength of Resilon/Epiphany SE was not different after irrigation with 5.25% NaOCl + EDTA or 1.3% NaOCl + MTAD.

Push-out bond strength of Resilon/Epiphany self-etch to intraradicular dentin after retreatment: a preliminary study.

INTRODUCTION: Retreatment procedures might affect the adhesion capability of refilling materials to dentinal walls. The purpose of this study was to compare the effect of different retreatment techniques on bond strength of Resilon (Resilon Research LLC, Madison, CT)/Epiphany (Pentron Clinical Technologies, LLC, Wallingford, CT) self-etch (SE) with radicular dentin after canal reobturation. METHODS: Sixty extracted single-rooted human teeth were prepared using Mtwo rotary files (VDW, Munich, Germany) and obturated with Resilon/Epiphany SE. The roots were randomly divided into four groups; in group 1, no retreatment procedure was done; group 2 was retreated using Mtwo R/Mtwo files; group 3 was retreated using Mtwo R/Mtwo combined with chloroform; and group 4 was retreated using Mtwo R/Mtwo combined with Endosolv R (Septodont, Paris, France). The root canals were then reobturated with Resilon/Epiphany SE. One-millimeter slices of midroot dentin were prepared for the push-out test (n=30 slices per group). Failure modes after the push-out test were examined under microscopy. The data were analyzed by using a one-way analysis of variance and the Dunnett post hoc test. RESULTS: Group 3 showed significantly the lowest mean bond strength (p<0.02). No significant difference was found between the values of groups 1, 2, and 4 (p>0.26). The mode of bond failure was predominantly adhesive for all groups. CONCLUSIONS: This study showed that the bond strength of Resilon/Epiphany SE after root canal retreatment using Mtwo files, either alone or combined with Endosolv R, was not significantly different from that of nonretreated specimens. Chloroform used for retreatment had an adverse effect on the bond strength of Resilon/Epiphany SE after root canal reobturation.

Healing of apical periodontitis after endodontic treatment with and without obturation in dogs.

The principle of obturation of the root canal space is generally accepted. This belief has dominated the field of endodontics despite the absence of credible scientific evidence. Little information is available on the possible relationships between endodontic success and obturation of the root canal system. The present study compares the healing of instrumented and obturated versus instrumented and nonobturated root canal systems with apical periodontitis. Fifty-six root canals in 28 third and fourth bilateral lower premolar teeth with completely formed apices in seven mixed German Shepherd dogs were used. Apical lesions were created by accessing the canals, removing the pulp and leaving them open to the oral environment for 42 days. The teeth in the control group were instrumented, irrigated, and then obturated using a lateral condensation technique with gutta-percha cones and AH26 Plus as the endodontic sealer. The teeth in the experimental group were instrumented and irrigated without obturation. All teeth in both groups were sealed coronally. After 190 days, the animals were euthanized. Vital perfusion with 10% formalin through common carotid artery was performed. Thirty to 40 serial 5-microm thick sections were obtained from each root and stained with hematoxylin and eosin for histological evaluation by observer blinded to the treatment allocation. The control group showed less cementum and dentin resorption in comparison with test group (p < 0.5). No statistically significant difference was found in other parameters between the control and test groups (p > 0.05). The noteworthy finding of this study was that there was no difference in healing of apical periodontitis between the instrumented and obturated and instrumented and nonobturated root canal system. The success of endodontic treatment ultimately depends on the elimination of the microorganism, host response and mechanical closure (coronal seal) of treated root canals that may provide a potential for future bacterial contamination.