Impact of Adjunctive Laser Irradiation on the Bacterial Load of Dental Root Canals: A Randomized Controlled Clinical Trial.

Johannes-Simon Wenzler,Roland Frankenberger,Andreas Braun,Wolfgang Falk

doi:10.3390/antibiotics10121557

Johannes-Simon Wenzler, Roland Frankenberger + Show 2 more

Open Access

https://doi.org/10.3390/antibiotics10121557

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Abstract

Successful root canal treatment depends on the adequate elimination of pathogenic bacteria. This study evaluated the effectiveness of a novel 445-nm semiconductor laser in reducing bacteria after chemomechanical root canal treatment. Microbiological specimens from 57 patients were collected after emergency endodontic treatment, in the following sequence: 1, removal of the temporary filling material; 2, chemomechanical treatment; 3, rinsing with sodium hypochlorite (3%) along with one of three adjuvant protocols (n = 19 in each group). The adjuvant procedures were: (a) sodium hypochlorite rinsing alone (3%); (b) laser irradiation; (c) combined sodium hypochlorite rinsing and laser irradiation. The diode laser was set to 0.59 W in continuous-wave mode (CW) for 4 × 10 s. After the flooding of the root canal with saline, specimens were collected using paper points and analyzed microbiologically. Statistically significant reductions in the bacterial load were observed in all three groups (p < 0.05): 80.5% with sodium hypochlorite rinsing alone and 58.2% with laser therapy. Both results were lower than with the combination of sodium hypochlorite rinsing and 445-nm laser irradiation, at 92.7% (p < 0.05). Additional disinfection of the root canal can thus be achieved with 445-nm laser irradiation after conventional chemical disinfection with sodium hypochlorite solution.

Highlights

Almost all conditions that require endodontic treatment are caused by, or later exacerbated by, microbial infections [1]
This study evaluated the effectiveness of a novel 445-nm semiconductor laser in reducing bacteria after chemomechanical root canal treatment
In group (a), additional rinsing with sodium hypochlorite resulted in a median total bacterial load (TBL) of 4.03 × 104 colony-forming units (CFUs), representing a percentage bacterial reduction of 80.54% (Tables 1 and 2)

Summary

Introduction

Almost all conditions that require endodontic treatment are caused by, or later exacerbated by, microbial infections [1]. Between 102 and 107 bacteria can be detected in an infected root canal system [2] The migration of these bacteria into all parts of the root canal system and into the surrounding dentin makes it almost impossible to eliminate them completely. The cleaning of hard-to-reach parts of the canal sections, mechanical instrumentation of inaccessible side canals, and thorough disinfection of the remaining surrounding dentin are decisive factors that determine the lasting success of endodontic treatment [3]. Rinsing solutions such as sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), and ethylenediaminetetraacetic acid (EDTA) are generally used for this purpose. In combination with the mechanical instrumentation of the canal lumen, carefully performed chemomechanical root canal preparation can eliminate over 95% of the microorganisms in the root canal system [4,5]

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