Introduction Revascularization treatment is rapidly becoming an accepted alternative for the management of endodontic pathology in immature permanent teeth with necrotic dental pulps. However, the success and timing of clinical resolution of symptoms and of radiographic outcomes of interest, such as continued hard tissue deposition within the root, are largely unknown. Methods In this prospective cohort study, 20 teeth were treated with a standardized revascularization treatment protocol, and monitored for clinical and radiographic changes for one year. Standardized radiographs were collected at regular intervals and radiographic changes were quantified. Results All 20 treated teeth survived during the 12 month follow up period and all 20 also met the clinical criteria for success at 12 months. As a group, the treated teeth demonstrated a statistically significant increase in radiographic width and length, and a decrease in apical diameter, although the changes in many cases were quite small such that the clinical significance is unclear. The within-case percent change in apical diameter after 3 months was 16% and had increased to 79% by 12 months, with 55% (11/20) showing complete apical closure. The within-case percent change in root length averaged less than 1% at 3 months and increased to 5% at 12 months. The within-case percent change in root thickness averaged 3% at 3 months and 21% at 12 months. Conclusions Although clinical success was highly predictable with this procedure, clinically meaningful radiographic root thickening and lengthening is less predictable at one year of follow up. Apical closure is the most consistent radiographic finding.

Within the limitation of this study, it can be concluded that residual pulp tissue can remain in the canals after revascularization procedures of immature teeth with artificially induced pulp infection. This can lead to the misinterpretation that true pulpal regeneration has occurred. Ingrowth of apical bone into the root canals undergoing revascularization can interfere with normal tooth eruption if ankylosis occurs.

To evaluate the antibacterial efficacy of double antibiotic paste (DAP), silver nanoparticle (AgNP) gel, and tailored amorphous multiporous bioactive glass (TAMP-BG) in concentrations suitable for regenerative endodontics (RE) against 3-week-old Enterococcus faecalis biofilms after 24 hours and 7 days. Results: Radicular human dentin specimens were prepared and inoculated with E. faecalis to form 3-week-old biofilms. DAP (1 mg/mL), AgNPs 0.02%, and TAMP-BG 100 mg/mL, in methylcellulose gel formulations, were used as antimicrobials. The biofilm disruption assay was done followed by quantification of bacterial colony-forming units and scanning electron microscopic analysis. Results showed that 1 mg/mL of DAP or AgNPs 0.02% provided significant antibiofilm effects at both time intervals. Both DAP and AgNPs significantly reduced bacterial counts and biofilms after 7 days compared with 24 hours. Furthermore, 100 mg/mL of TAMP-BG had a comparable antibiofilm effect, but it was less potent than DAP and AgNPs at both time intervals. Conclusions: DAP (1 mg/mL), 0.02% AgNPs, and TAMP-BG (100 mg/mL) can significantly reduce E. faecalis biofilms. However, complete elimination was only possible with DAP and AgNPs.

INTRODUCTION: Different irrigations solutions may cause alteration in the physicochemical properties of dentin structure thereby affecting the microhardness of root canal dentin. OBJECTIVES: to evaluate the effect of different irrigation protocols on microhardness of human root canal dentin. MATERIALS AND METHODS: Forty extracted single rooted lower premolars were used. All teeth were instrumented using manual stainless steel files and irrigated by 2ml distilled water between each file, then were sectioned by longitudinal splitting of each tooth. The root halves were randomly assigned into 4 parallel groups (n=10) and immersed for 5 minutes with one of the following irrigants: Group I: 10 ml of 2.5% Sodium Hypochlorite (NaOCL), Group II: 10 ml of 17% ethylene diamine tetra-acetic acid (EDTA) followed by 10 ml of 2.5% NaOCL, Group III: 10 ml of 2.5% NaOCL followed by 10 ml of 2% chlorhexidine digluconate (CHX), Group IV: 10 ml of 2.5% NaOCL followed by 10 ml distilled water then were followed by 10ml of 2% CHX. Ten root halves from each group were prepared to measure dentin microhardness at baseline measurement and after treatment to determine the change in microhardness, using Vickers tester. RESULTS: Data were analysed using t-test, ANOVA test and Post Hoc test.Group II showed the highest percentage decrease in microhardness values, followed by group III, then group IV and the lowest was group I. All groups showed a significant difference between each other (P < 0.05), except group III and IV. The coronal third showed the highest percentage decrease with significant difference between apical and middle thirds (P < 0.05), in which there was no significant difference between them. CONCLUSIONS: CHX is the best final irrigant if there is excellent intermediate flush for prevention of its precipitation with NaOCL.The coronal third needs conservative approach as it is the most affected third.

INTRODUCTION:Revascularization procedures have been limited to immature teeth but application to mature teeth should be clinically investigated as an alternative to conventional root canal treatment. The translation of regenerative endodontic procedures into treating mature teeth is challenging and depends on efficient root canal disinfection, proper size of the apical foramen, the availability and delivery of stem cells into the root canal system. OBJECTIVES: Evaluation of revascularization in mature teeth after enlargement of the apical foramen to size 35 K-file. MATERIALS AND METHODS: Three necrotic incisors with mature roots and apical periodontitis in three patients ranging from 20-30 years old were treated by revascularization procedures. Access opening was performed. The canal was mechanically instrumented to the radiographic apex. The apical foramen was enlarged with a size 35 K-file. Triple antibiotic paste (0.1 mg/ml) was applied in the canal using a syringe. After three weeks, the medication was removed with 20 ml of 1.5% sodium hypochlorite followed by final irrigation with 20 ml of 17% EDTA. Bleeding was induced in the root canal and mineral trioxide aggregate (MTA) was placed approximately 3-4 mm below the CEJ. The tooth was restored with a layer of glass ionomer followed by composite resin. The patient was scheduled for follow up and evaluation of healing after 3 months, 6 months and 9 months. Resolution of apical periodontitis and regression of clinical signs and symptoms were observed during the follow up periods. RESULTS: After a follow-up period of 9 months, the three teeth demonstrated radiographic evidence of periapical healing with absence of clinical signs and symptoms. CONCLUSIONS: The present cases demonstrated a favorable outcome of the revascularization procedure in mature necrotic incisors with chronic apical periodontitis.