Regenerative endodontic procedures (REPs) have emerged as a treatment option for immature necrotic teeth to allow the reestablishment of a newly formed vital tissue and enable continued root development. The apical papilla stem cells (SCAPs) play an important role in physiologic root development and may also contribute to further root development during REPs. The goal of these case reports is to show evidence of the apical papilla survival and development, in human teeth with apical periodontitis, after REPs, with 5-year clinical and radiographic follow-up. In the first case, an 11-year-old girl with acute apical abscess of tooth 15 was referred for a REP. Treatment was performed with an intracanal medication followed by induction of a blood clot and a Mineral Trioxide Aggregate (MTA) cervical barrier. The 5-year follow-up showed an appreciable increase in root length as well as root canal thickness. In case 2, a 16-year-old girl was referred for endodontic treatment of tooth 21. The parents of the patient recalled a previous dental trauma (no specified on the patient records) on tooth 21 at age 7. The dental history reports a previous endodontic treatment failure and presence of a long-standing sinus tract. A mineralized tissue beyond the root apical portion could be seen at the preoperative X-ray. Nonsurgical root canal retreatment with an apical barrier was suggested as the treatment plan and accepted by the patient. After 2 weeks, the patient was recalled for a follow-up appointment presenting spontaneous pain, swelling, and sinus tract. Apical surgery was performed. Histopathological assessment of the apical root fragment collected showed the presence of dentin, cementum and pulp tissue, including odontoblasts. The 5-year follow-up depicted complete apical healing. The present case reports support survival and continued potential differentiation of the apical papilla after endodontic infection.

Periapical radiographs (PR) have limitations in assessing endodontic treatment outcomes, which can be addressed by cone beam computed tomography (CBCT). This systematic review evaluates primary root canal treatment and retreatment outcomes using CBCT, focusing on periapical healing, success, and prognostic factors. A literature search (in PubMed, Embase and Web of Science) was performed up to March 8, 2024, in collaboration with a medical information specialist. Three reviewers independently performed article selection and data extraction. Risk of bias was assessed, and evidence quality using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Meta-analysis and meta-regression established pooled periapical healing and outcome rates, 95% confidence intervals (CIs), and identify outcome predictors (P < .05). Nineteen studies were included in the meta-analysis. The pooled periapical healing rate using 'loose criteria' was 87% (95% CI: 81-91%) for teeth and 84% (95% CI: 78-88%) for roots; using 'strict criteria' was 36% (95% CI: 22-53%) for teeth, and 44% (95% CI: 16-76%) for roots. The weighted pooled success rates for teeth were 85% (95% CI: 80-89%) under 'loose criteria' and 45% (95% CI: 31-59%) under 'strict' criteria. Meta-regression identified outcome predictors include number of visits, irrigant type, tooth type, operator experience, apical preparation size and taper, and obturation technique. CBCT reveals lower success rates under strict criteria compared to loose criteria (36% vs. 88%). While CBCT offers greater diagnostic accuracy, its routine use for outcome evaluation may not be necessary, as it yields results similar to PR under loose criteria.

This study evaluated the biocompatibility of a new silicone-based sealer (GuttaFlow Bioseal) in rat subcutaneous tissue and compared the results with those for GuttaFlow2 and AH Plus. Each of 16 Wistar rats received four subcutaneous tissue implants, namely, GuttaFlow Bioseal, GuttaFlow2, AH Plus, and one empty polyethylene tube. Eight rats were euthanized at day 8 and the remaining eight at day 30. Histological sections were stained with haematoxylin and eosin and analysed with a light microscope. Scores were established for inflammatory reaction, macrophage infiltrate, thickness of the fibrous capsule, and vascular changes. Differences between groups were assessed by using the Friedman test with Bonferroni correction. Histological analysis showed that GuttaFlow Bioseal had the lowest inflammatory reaction of all tested sealers at day 8. At day 30, the silicone-based sealers had similar inflammation profiles, but inflammation scores were nonsignificantly higher for AH Plus than for the negative control. The inflammatory reaction decreased from day 8 to day 30 in all sealers. GuttaFlow Bioseal had the most macrophage infiltrate. Under the present experimental conditions, GuttaFlow Bioseal induced limited inflammatory reactions at days 8 and 30, and initial inflammatory reactions to GuttaFlow2 and AH Plus subsided within 30 days. All tested sealers exhibited satisfactory biocompatibility at day 30 after subcutaneous implantation.

This study aimed to investigate the effect of unintentional AH Plus® sealer extrusion on the outcome of nonsurgical root canal treatment and retreatment in teeth with apical periodontitis (AP) compared to teeth with AP and no sealer extrusion at the 1-year follow-up. In a retrospective case-control study conducted from September 2016 to September 2021, teeth presenting clinical and radiographic signs of AP prior to treatment were included. The study comprised two groups: AH Plus® sealer extrusion (n=60): initial root canal treatment or nonsurgical retreatment with unintentional apical extrusion of AH Plus® sealer; No AH Plus® sealer extrusion (n=60) underwent the same treatment without sealer extrusion. Additional factors, including sex, age, tooth type, tooth location, and treatment type, were recorded as potential outcome predictors. At 1-year follow-up, teeth were evaluated clinically and radiographically, and outcomes were classified as favorable (healed/healing) or unfavorable (uncertain/non-healing). Statistical analyses, such as the χ2 test, logistic regression, and Mann-Whitney U test, were employed for data analysis. A favorable outcome was observed in 88.4% and 85% of the cases of the AH Plus® sealer extrusion and no AH Plus® sealer extrusion group, respectively. There was no statistically significant difference between the groups in terms of outcomes (p>0.05) when analyzed categorically or ordinally. Of independent variables, nonsurgical retreatment showed lower healing of AP in both groups. Unintentional AH Plus® sealer extrusion did not affect the healing of AP. However, initial root canal treatment showed better healing of AP than nonsurgical retreatment in the presence of Ah Plus® sealer extrusion. The analyzed outcome predictors had no effect on treatment outcome.