Edta

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Journal of Oral Science, Vol. 53, No. 3, 355-360, 2011

Original

Additive effect of a diode laser on the antibacterial activity of 2.5% NaOCl, 2% CHX and MTAD against Enterococcus faecalis contaminating root canals: an in vitro study
Payman Mehrvarzfar1), Mohammad Ali Saghiri2), Armen Asatourian3), Reza Fekrazad4), Kasra Karamifar1), Gita Eslami5) and Bahareh Dadresanfar1)2)Department 1)Department

of Endodontics, Dental Branch, Islamic Azad University, Tehran, Iran of Dental Materials, Dental Branch, Islamic Azad University, Tehran, Iran 3)Private Practice, Tehran, Iran 4)Dental Research Center for Laser, Dental Faculty, AJA University and Tehran University of Medical Sciences, Tehran, Iran 5)Shahid Beheshti University of Medical Science, Tehran, Iran
(Received 7 Marchand accepted 14 July 2011)

Abstract: This in vitro study was performed to evaluate the effect of a diode laser and common disinfectants used in combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and twocontrol groups (n = 5). In the first group, the teeth were rinsed for 5 min with either sterile saline, 2.5% NaOCl, or MTAD, or for 1 min with 2% chlorhexidine gluconate (CHX). In the other group, samples were additionally irradiated with a 810-nm diode laser at 2 W output for 5 × 5 s. Intracanal bacterial sampling was done, and the samples were plated to determine the CFU count. In the first group,2.5% NaOCl was as effective as 2% CHX and significantly more effective than MTAD (P < 0.008). In the second group, either MTAD, 2% CHX or 2.5% NaOCl in combination with laser treatment had a similar effect. Absence of growth was seen only
Correspondence to Dr. Mohammad Ali Saghiri, No 4, 10th Neyestan Alley, Pasdaran Ave., Tehran, Iran Tel: +98-21-44420250 Fax: +98-21-22564573 E-mail:saghiri@gmail.com

for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system. (J Oral Sci 53,355-360, 2011) Keywords: chlorhexidine gluconate; combined effect; diode laser; MTAD, sodium hypochlorite.

One of the goals of root canal therapy is to completely disinfect the root canal and its three-dimensional tubular network (1). Use of mechanical instrumentation alone cannot sufficiently debride and clean this complex tubular network (2,3). Many irrigation solutions have been used for rootcanal treatment along with mechanical instrumentation to achieve better debridement. However, because these solutions act through direct contact with targets and have a limited penetration depth into irregularities of root canal walls, they are unable to eliminate microorganisms from deeper layers of the dentin (4,5).

Introduction

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106 single rooted premolars prepared and autoclaved5 teeth were chosen as Negative controls

101 samples were inoculated with E. faecalis and incubated for 24 h

5 teeth served as Positive controls

Part I
First Group (Experimental) n = 48

5-min irrigation with saline (n = 12)

5-min irrigation with 2.5% NaOCl (n = 12) 1-min irrigation with 2%CHX (n = 12)

5-min irrigation with MTAD (n = 12)

Part II
Second Group (Experimental)n = 48

5-min irrigation with saline + Laser irradiations (n = 12) 5-min irrigation with 2.5% NaOCl + laser irradiations (n = 12) 1-min irrigation with 2% CHX + Laser irradiations (n = 12) 5-min irrigation with MTAD + Laser irradiations (n = 12)

Microbiological sampling 24 hours post operations

Fig. 1 Flow chart of the methodology employed.

Many researchers have discussed the...