Sharonit Sahar-Helft, Joshua Moshonov, Adam Stabholz
Although the interest in clinical use of laser systems for endodontic procedures is increasing there are still some concerns associated with their use, mainly, lack of sufficient well-designed clinical studies, which clearly demonstrate the advantage of lasers over currently used conventional methods and techniques. Bacterial contamination of the root canal system is considered the principle etiologic factor for the development of pulpal and periapical lesions. Obtaining a root canal system free of irritants is a major goal of root canal therapy. Biomechanical instrumentation of the root canal system has been suggested to achieve this task. However, because of the complexity of the root canal system, it has been shown that the complete elimination of debris and achievement of a sterile root canal system is very difficult and a smear layer, which covers the instrumented walls of the root canal, is formed. The task of cleaning and disinfecting a root canal system which contains microorganisms gathered in a biofilm became very difficult; certain bacterial species become more virulent when harbored in biofilm, demonstrating stronger pathogenic potential and increased resistance to antimicrobial agents since Biofilm has the ability to prevent the entry and action of such agents. Bergmans et al, tried to define the role of laser as a disinfection tool by using Nd:YAG laser irradiation on some endodontic pathogens ex vivo. The apparent consensus is that laser irradiation emitted from laser systems utilized in dentistry has the potential to kill microorganisms. In most cases the effect is directly related to the amount of irradiation and to its energy level.