Revitalization of necrotic mature permanent incisors with apical periodontitis: a case report.

Despite considerable focus on the regenerative endodontic treatment of immature teeth with necrotic infected pulps and apical periodontitis, little data exist with regard to its possible implementation in necrotic permanent teeth with complete apical and radicular development. The present report describes the procedures and outcome of a regenerative endodontic treatment approach in 2 previously-traumatized incisors with closed apex with apical periodontitis. A 2-visit treatment procedure was employed. At initial visit, the root canals were copiously irrigated, followed by placement of a triple antibiotic paste containing ciprofloxacin, metronidazole, and clindamycin into the root canals. After 4 weeks, the antibiotic paste was removed, and apical bleeding was initiated with size 10 hand files beyond the apices. The root canals were coronally sealed with mineral trioxide aggregate, and the access cavities were restored with bonded resin composite. At post-operative 60 months, both teeth were remained asymptomatic, with the recall radiographs showing complete resolution of apical radiolucency and reestablishment of periradicular tissues. In both teeth, the dimensions of root space remained unchanged as verified by image analysis. The revitalization protocol utilizing root canal disinfection and induced apical bleeding in necrotic, closed-apex incisors may offer a clinically acceptable alternative to conventional root canal treatment.

A comparison of residual smear layer and erosion following different endodontic irrigation protocols tested under clinical and laboratory conditions.

OBJECTIVE: To compare the smear layer removal efficacy and erosive effects of different irrigation protocols under clinical and laboratory conditions. MATERIALS AND METHODS: Mandibular third molars (n = 32) of 30-45 year-old patients were instrumented with rotary files and were randomly assigned to one of the following groups for final irrigation: (1) 5.25% NaOCl; (2) 17% EDTA; and (3) BioPure MTAD. Thereafter, the teeth were immediately extracted and processed for micromorphological investigation. In vitro specimen pairs were prepared by repeating the clinical experiments on freshly-extracted mandibular third molars. To compare open and closed systems, laboratory experiments were repeated on 32 additional teeth with enlarged apical foramen. The cleanliness of the root canals and the extent of erosion were assessed by environmental scanning electron microscopy. RESULTS: Specimens prepared under clinical and laboratory conditions had similar cleanliness and erosion scores (p > 0.05). Under both conditions, the tested solutions were more effective in removing the smear layer in the coronal and middle regions than in the apical one. Comparison of closed and open systems showed similar levels of cleanliness and erosion in all regions (p > 0.05), with the exception of 17% EDTA showing significantly higher levels of cleanliness and erosion in the apical third of open-end specimens. CONCLUSIONS: Based on clinical correlates of in vitro root canal cleanliness and erosion, laboratory testing of root canal irrigants on extracted teeth with closed apices can serve as a reliable method to simulate the clinical condition. EDTA was the most effective final irrigation solution in removing the smear layer at the expense of yielding the greatest erosive effect.

Effect of ethylenediaminetetraacetic acid on root fracture with respect to concentration at different time exposures.

INTRODUCTION: The objective of this study was to evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on root fracture with respect to various concentrations at different time exposures. METHODS: A total of 48 mandibular incisors were selected. Eight nonprepared roots were selected as a negative control. The remaining 40 specimens were instrumented with rotary files and randomly assigned to one of the following groups for final irrigation: (1) 10 mL distilled water for 10 minutes (positive control); (2) 10 mL of 17% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (3) 10 mL of 5% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (4) 10 mL of 17% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute; (5) 10 mL of 5% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute. Thereafter, the root canals were filled by using AH26 root canal sealer with a single-cone technique. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with 1-way analysis of variance and Student's t test. RESULTS: Statistically significant differences were detected among the groups (P < .05). The highest mean fracture resistance was obtained from the group treated with 5% EDTA for 10 minutes. This is about 2 times more than the weakest mean fracture resistance, which was obtained from the 17% EDTA-10 minute group. CONCLUSIONS: The fracture resistances of endodontically treated roots were found to be differently affected by the various concentrations of EDTA at different time exposures.

Dentin moisture conditions affect the adhesion of root canal sealers.

INTRODUCTION: The purpose of this study was to evaluate the effects of intraradicular moisture conditions on the push-out bond strength of root canal sealers. METHODS: Eighty root canals were prepared using rotary instruments and, thereafter, were assigned to 4 groups with respect to the moisture condition tested: (1) ethanol (dry): excess distilled water was removed with paper points followed by dehydration with 95% ethanol, (2) paper points: the canals were blot dried with paper points with the last one appearing dry, (3) moist: the canals were dried with low vacuum by using a Luer adapter for 5 seconds followed by 1 paper point for 1 second, and (4) wet: the canals remained totally flooded. The roots were further divided into 4 subgroups according to the sealer used: (1) AH Plus (Dentsply-Tulsa Dental, Tulsa, OK), (2) iRoot SP (Innovative BioCeramix Inc, Vancouver, Canada), (3) MTA Fillapex (Angelus Indústria de Produtos Odontológicos S/A, Londrina, Brasil), and (4) Epiphany (Pentron Clinical Technologies, Wallingford, CT). Five 1-mm-thick slices were obtained from each root sample (n = 25 slices/group). Bond strengths of the test materials to root canal dentin were measured using a push-out test setup at a cross-head speed of 1 mm/min. The data were analyzed statistically by two-way analysis of variance and Tukey tests at P = .05. RESULTS: Irrespective of the moisture conditions, iRoot SP displayed the highest bond strength to root dentin. Statistical ranking of bond strength values was as follows: iRoot SP > AH Plus > Epiphany ≥ MTA Fillapex. The sealers displayed their highest and lowest bond strengths under moist (3) and wet (4) conditions, respectively. CONCLUSIONS: The degree of residual moisture significantly affects the adhesion of root canal sealers to radicular dentin. For the tested sealers, it may be advantageous to leave canals slightly moist before filling.

Surface porosity of hand-mixed, syringe-mixed and encapsulated set endodontic sealers.

OBJECTIVE: The objective of this study was to investigate the surface porosity of hand-mixed, syringe-mixed and encapsulated set endodontic sealers using image analysis. STUDY DESIGN: Eight different root canal sealers (AD Seal/Meta Biomed; AH Plus/Dentsply; MM Seal/Micromega; AH Plus Jet/Dentsply; EndoREZ/Ultradent; Epiphany/Pentron; GuttaFlow/Coltène; RealSeal/Sybron Endo) were prepared in accordance with the manufacturer's recommendations and dispensed into plastic rings (n = 10/group). Following set of the specimens, scanning electron photomicrographs of the sealer surfaces were taken at standard magnification. The area fraction and the minimum-maximum diameters of surface pores were calculated on the micrographs using ImageJ open-source image analysis software. Statistical comparisons were made between the sealers with respect to the area fractions and number of pores (Kruskal-Wallis test, P < .05). RESULTS: The endodontic sealers differed significantly in both the percentage of area fraction and pore count (P < .001). The surface porosity of the methacrylate-based sealers Epiphany and RealSeal were significantly lower than those of resin- and silicone-based sealers. With the exception of AD Seal, hand-mixed sealers displayed significantly higher surface porosity than those of syringe-mixed ones (P < .001). The encapsulated sealer GuttaFlow exhibited the highest surface area fraction of pores. CONCLUSION: The mixing method influences the surface porosity of set endodontic sealers.

Effects of different irrigation regimens on the sealing properties of repaired furcal perforations.

OBJECTIVE: The pulp chamber is inevitably exposed to irrigants during endodontic therapy. This study aimed to investigate whether different irrigation regimens would alter the sealing ability of repaired furcal perforations. STUDY DESIGN: Pulp chambers of 90 extracted human molars were accessed, after which standardized diamond bur-cut perforations were created in the center of the pulp chamber floor. The canal orifices and the apical end of roots were sealed with acid-etch composite resin. Eighty teeth were randomly divided into 2 groups (n = 40/group) according to the material used for repairing the perforation defects: (1) Mineral trioxide aggregate (MTA), (2) Super-EBA. The remaining teeth (n = 10) served as controls. The specimens were further subgrouped according to the irrigation regimens applied over the repair site (n = 10/group): (a) 5.25% NaOCl, (b) 5.25% NaOCl + EDTA, (c) 5.25% NaOCl + MTAD, and (d) No irrigation. Coronal leakage was measured by the fluid-filtration method at 1 day and 1 week. RESULTS: Fluid conductance was not affected by the type of repair material (P = .964) or time (P = .726), but was affected significantly by the irrigation regimens in the following ranking: (P < .001): NaOCl < or = No Irrigation < NaOCl + MTAD < or = NaOCl + EDTA. CONCLUSION: The sealing ability of furcal perforations repaired with MTA or Super-EBA were differentially affected by exposure to the tested irrigation regimens.

Effects of different light-curing units and obturation techniques on the seal of the Resilon/Epiphany system.

The purpose of this study was to compare the sealing ability of a resin- and polymer-based root canal obturation system (Resilon; Resilon Research LLC, Madison, CT/Epiphany; Clinical Technologies, Wallingford, CT) used in conjunction with different light-curing units and obturation techniques. A total of 120 decrowned single-rooted human teeth were used. After preparation of the root canals with 0.06 taper nickel-titanium rotary files to size 30, the roots were randomly assigned into three experimental groups according to the obturation technique used: (1) single cone, (2) cold lateral compaction, and (3) System B + Obtura. In all groups, the specimens were randomly assigned into four subgroups according to the polymerization method that was used to cure Epiphany sealer from the coronal aspect: (1) quartz-tungsten-halogen (QTH), (2) light-emitting diode (LED), (3) plasma-arc curing (PAC), and (4) chemical cure (uncured). Leakage was measured by the fluid-filtration method at 1 day and 1 week. Statistical analysis was performed by using Kruskal-Wallis and Wilcoxon signed-rank tests at p < 0.001. Fluid conductance of all groups increased significantly within time (p < 0.001). The tested obturation techniques had no significant effect on the leakage values (p = 0.433). The following statistical ranking was obtained for fluid-filtration values: uncured > PAC > LED > QTH (p < 0.001).