Publication: Journal of Endodontics

Adjunctive steps for disinfection of the mandibular molar root canal system: a correlative bacteriologic, micro-computed tomographic and cryopulverization approaches

Flávio R.F. Alves, Carlos V. Andrade-Junior, Marília F. Marceliano-Alves, Alejandro R. Pérez, Isabela N. Rôças, Marco A. Versiani, Manoel D. Sousa-Neto, José C. Provenzano, José F. Siqueira Jr.

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Abstract

Introduction

This study evaluated the disinfecting ability of chemomechanical preparation with rotary nickel-titanium instruments, followed by 2 distinct adjunctive procedures in the root canals of extracted mandibular molars by means of a correlative analytical approach.

Methods

Twenty-two extracted mandibular molars were selected and anatomically matched between groups on the basis of micro–computed tomographic analysis. In the first phase of the experiment, root canals were contaminated with Enterococcus faecalis and subjected to chemomechanical preparation with BT RaCe instruments and 2.5% NaOCl irrigation. Then either XP-Endo Finisher instrument or passive ultrasonic irrigation was used to supplement disinfection. Micro–computed tomography was used to show whether the percentage of unprepared areas correlated to bacterial counts. In the second phase, the same teeth were contaminated once again, and the adjunctive procedures were used. Samples from the isthmus area of mesial roots and the apical 5-mm fragment of distal roots were obtained by cryopulverization. Samples taken before and after treatment steps in both phases were evaluated by quantitative polymerase chain reaction and statistically analyzed.

Results

In phase 1, preparation in both groups resulted in substantial decrease of bacterial counts (P < .001). The adjunctive approaches led to a further small bacterial reduction, which was significant for XP-Endo Finisher (P < .05). No significant differences were observed between groups for persisting bacterial counts. Correlative analysis revealed no statistically significant relationship between bacterial reduction and the percentage of unprepared areas (P > .05). In phase 2, both methods had significant antibacterial effects in the main canal, but none of them could predictably disinfect the isthmus/recess areas.

Conclusions

Both XP-Endo Finisher and passive ultrasonic irrigation exhibited antibacterial effectiveness, but only the former caused a significant reduction in the bacterial counts after chemomechanical preparation. None of them were effective in predictably disinfecting the isthmus/recess areas.  

Publication: Journal of Endodontics

Keleş A, Alçin H, Sousa-Neto MD, Versiani MA. Supplementary Steps for Removing Hard Tissue Debris from Isthmus-containing Canal Systems. J Endod. 2016. doi: 10.1016/j.joen.2016.07.025. 

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Publication: International Endodontic Journal

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Publication: International Endodontic Journal

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Hard Tissue Debris Removal: XP Endo Finisher

Book Chapter: The Root Canal Biofilm

Very honored for being invited by Dr Luis E. Chávez de Paz, Dr. Christine M. Sedgley and Dr. Anil Kishen to write the chapter entitled "Root Canal Anatomy: Implications in Biofilm Disinfection" (pages 155-187) with Dr. Ronald Ordinola-Zapata in their new book "The Root Canal Biofilm". For more information, please click HERE.

Publication: International Endodontic Journal

Micro-CT evaluation of the efficacy of hard tissue removal from the root canal and isthmus area by positive and negative pressure irrigation systems

M. A. Versiani, F. R. F. Alves, C. V. Andrade-Junior, M. F. Marceliano-Alves, J. C. Provenzano, I.N.Rocas, M. D. Sousa-Neto & J. F. Siqueira Jr

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Book Chapter: Internal Anatomy (Basrani 1st Ed.)

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(Only in English)

Publication: Clinical Oral Investigations

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Abstract

Objectives

The aim of this study was to introduce a methodology to map irrigant spreadability within the root canal space using micro-computed tomography (micro-CT).

Materials and methods

Mandibular molars presenting Vertucci’s types I and II canal configurations were selected, and four scans using isotropic resolution of 19.5 μm were accomplished per tooth: prior to treatment (S1), after glide path (S2) and after root canal preparation (S3 and S4). A contrast solution (CS) was used to irrigate the canals at stages S2 and S4. The touched and untouched surface areas of the canals, the volume of irrigant-free areas and the percentage volume occupied by the CS were calculated. Density, surface tension and the spread pattern of the CS and 2.5 % NaOCl were also evaluated.

Results

In the type I mesial root, there was an increase in the percentage volume of free-irrigated areas from S2 to S4 preparation steps, whilst in the distal roots and type II mesial root, a decrease of irrigant-free areas was observed. The use of CS allowed the quantification of the touched surface area and the volume of the root canal occupied by the irrigating solution. Density (g/mL) and surface tension (mN/m) of the CS and 2.5 % NaOCl were 1.39 and 47.5, and 1.03 and 56.2, respectively. Besides, a similar spread pattern of the CS and 2.5 % NaOCl in a simulated root canal environment was observed.

Conclusions

This study introduced a new methodology for mapping the irrigating solution in the different stages of the root canal preparation and proved useful for in situ volumetric quantification and qualitative evaluation of irrigation spreading and irrigant-free areas.

Clinical relevance

Micro-computed tomographic technology may provide a comprehensive knowledge of the flush effectiveness by different irrigants and delivery systems in order to predict the optimal cleaning and disinfection conditions of the root canal space.