Supplementary Steps for Removing Hard Tissue Debris from Isthmus-containing Canal Systems.
BACKGROUND
The purpose of this ex vivo study was to evaluate the percentage reduction of accumulated hard tissue debris (AHTD) in the mesial root canal system of mandibular molars under different final irrigation regimens by means of micro-computed tomographic imaging.


METHODS
Sixty curved mesial roots of mandibular molars with 2 independent canals joint apically by an isthmus (Vertucci type II) were selected. Specimens were scanned at a resolution of 12.5 μm, anatomically matched, and distributed into 3 groups (n = 20) according to the preparation protocol: Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel), Reciproc (VDW GmbH, Munich, Germany), and Revo-S (Micro-Mega, Besançon, France) systems. Then, each group was subdivided into 2 subgroups (n = 10) according to the final irrigation protocol with the SAF or EndoVac system (Discus Dental, Culver City, CA). The percentage volume and percentage reduction of AHTD after root canal preparation and final irrigation protocols were statistically compared using 1-way analysis of variance, the paired sample and the independent Student's t tests. The level of significance was set at 5%.


RESULTS
Within groups, the mean percentage volume was significantly reduced after the final irrigation procedures in either the SAF (from 1.52%-1.78% to 1.01%-1.20%) or EndoVac (from 2.11%-2.23% to 1.31%-1.52%) subgroups (P < .05). In the experimental groups, the mean percentage reduction of AHTD ranged from 29.15%-39.90% after the irrigation protocols, with no statistical difference between groups (P > .05).


CONCLUSIONS
None of the irrigation approaches succeeded in rendering the mesial root canal system free of AHTD. A similar percentage reduction of AHTD was achieved after final irrigation protocols using either the SAF or EndoVac system.
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey. Electronic address: alikeles29@yahoo.com.
Ali
A
Keleş
Private Practice, Ankara, Turkey.
Hatice
H
Alçin
Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Manoel D
MD
Sousa-Neto
Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Marco A
MA
Versiani
D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology*; D004492:Edetic Acid / Q000008:administration & dosage; D006801:Humans; D008963:Molar / Q000000981:diagnostic imaging; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods*; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D007507:Therapeutic Irrigation / Q000379:methods*; D014092:Tooth Root / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology; D055114:X-Ray Microtomography / Q000379:methods
D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite
Hard tissue debris; isthmus; mandibular molar; mesial canal; micro–computed tomography; root canal irrigation