In vitro evaluation of Nd:YAG laser radiation at three different wavelengths (1064, 532, and 355 nm) on calculus removal in comparison with ultrasonic scaling.

Objective: The aim of this study was to investigate the effectiveness of laser treatment for calculus removal at different wavelengths and compare it with that of ultrasonic scaling (US).

Background Data: Conventional methods of treatment of periodontal tissues can be limited by morphology, root anatomy, and the periodontal pocket. In the search for an effective therapy to achieve a biocompatible root surface, laser treatment appeared in the field of periodontology.

Methods: Radiation from a Nd:YAG laser operating at the fundamental (1064 nm), second harmonic (532 nm) and third harmonic (355 nm) wavelengths was used for calculus removal. Environment scanning electron microscopy (ESEM) was used for the morphological analysis of the treated surfaces. The wavelength dependence of the ablation thresholds for calculus and cementum was evaluated by applying a photoacoustic technique.

Results: US achieved complete calculus removal, leaving a smooth and regular surface in a more efficient way than laser treatment. ESEM examination and photoacoustic methods confirmed a nonselective removal of material that entails partial cementum ablation of the root surface with the laser treatment.

Conclusion: UV radiation at 355 nm can constitute an adjunctive therapy to US, by eliminating toxic agents and the contaminated layer of cementum.