Evaluation of the Bactericidal Activity on Oral Organisms of the Nd-YAP Laser In Vitro

The bactericidal activity of a pulsed fibre-optic Nd-YAP laser on various strains of oral bacteria: Prevotella nigrescens, Streptococcus sanguis, Actinomyces viscosus (i), Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans and Peptostreptococcus micros (i) was evaluated. A 200-μm optical fibre was placed in Eppendorf tubes containing the different bacterial suspensions. At an energy of 170 mJ/30 Hz, 351 pulses of 150 μs were sufficient to kill the most resistant bacteria (i). The exposure time was 28 s. The temperature rise caused by the shots were measured in vitro at the surface of the roots of two groups of 10 single-rooted teeth. One group received 350 pulses; for the other the preparation time was fixed at 28 s. The temperature rose by 25.66°C for the first group and 25.25°C for the second.