Q-Switch Nd:YAG Laser-Assisted Decontamination of Implant Surface

Abstract

Peri-implantitis (PI) is an inflammatory disease of peri-implant tissues, it represents the most frequent complication of dental implants. Evidence revealed that microorganisms play the chief role in causing PI. The purpose of our study is to evaluate the cleaning of contaminated dental implant surfaces by means of the Q-switch Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser and an increase in temperature at lased implant surfaces during the cleaning process. Seventy-eight implants (titanium grade 4) were used (Euroteknika, Sallanches, France). Thirty-six sterile implants and forty-two contaminated implants were collected from failed clinical implants for different reasons, independent from the study. Thirty-six contaminated implants were partially irradiated by Q-switch Nd:YAG laser (1064 nm). Six other contaminated implants were used for temperature rise evaluation. All laser irradiations were calibrated by means of a powermetter in order to evaluate the effective delivered energy. The irradiation conditions delivered per pulse on the target were effectively: energy density per pulse of 0.597 J/cm2, pick powers density of 56 mW/cm2, 270 mW per pulse with a spot diameter of 2.4 mm, and with repetition rate of 10 Hz for pulse duration of 6 ns. Irradiation was performed during a total time of 2 s in a non-contact mode at a distance of 0.5 mm from implant surfaces. The parameters were chosen according to the results of a theoretical modeling calculation of the Nd:YAG laser fluency on implant surface. Evaluation of contaminants removal showed that the cleaning of the irradiated implant surfaces was statistically similar to those of sterile implants (p-value ≤ 0.05). SEM analysis confirmed that our parameters did not alter the lased surfaces. The increase in temperature generated at lased implant surfaces during cleaning was below 1 °C. According to our findings, Q-switch Nd:YAG laser with short pulse duration in nanoseconds is able to significantly clean contaminated implant surfaces. Irradiation parameters used in our study can be considered safe for periodontal tissue.

Assessment of Disinfection Potential of Q-Switch Nd: YAG Laser on Contaminated Titanium Implant Surfaces

“…Regarding the comparison of our findings with the current evidence found in the literature, a previous study of Namour et al [21] demonstrated that similar laser irradiation conditions to those used in our study using the Q-Switch Nd: YAG laser led to a total detachment of all organic and non-organic (calculus) elements, and therefore, a total elimination of calculus, organic, debris, germs, toxins, and any carbonic element. Another recent study by Namour et al [22] showed that irradiation conditions similar to the conditions used in our study can lead to the total elimination of multi-species biofilm from irradiated titanium surfaces [22].…”

“…Regarding the comparison of our findings with the current evidence found in the literature, a previous study of Namour et al [21] demonstrated that similar laser irradiation conditions to those used in our study using the Q-Switch Nd: YAG laser led to a total The null hypothesis was rejected because there is a significant difference between the level of disinfection of contaminated and untreated titanium surfaces (Group C) and those that have been contaminated and laser-treated (Group L) having total surface disinfection.…”

“…The irradiation parameters used in this study were similar to the irradiation parameters used by Namour et al [21,22] based on the theoretical modeling of the optimal energy density respecting the implant surfaces' porosity.…”

“…Among the available approaches in the literature, Namour et al [21] showed that the Q-switch Nd:YAG laser is able, when used with specific irradiation protocol and parameters (0.597 J/cm 2 ; 10 Hz, pulse duration of 6 nanoseconds), to accomplish an effective photo-desorption of the contaminants of the titanium implant surfaces with a minimal heat generation surrounding targeted surfaces around 1 • C that was considered to be below the threshold of bone damage [21]. The authors have made a theoretical modeling and calculation of the optimal laser fluency emitted in nanoseconds that can increase the temperature of titanium surfaces to allow the desorption of calculus, organic materials, and debris [21]. This resulted in the total absence of carbon and without causing any morphological change of the irradiated implant surfaces.…”

Assessment of Effects of Laser Light Combining Three Wavelengths (450, 520 and 640 nm) on Temperature Increase and Depth of Tissue Lesions in an Ex Vivo Study

“…Apart from wavelength, tissue response is affected by power, energy density and radiation dose. An increase in power and energy density leads to intensification of thermal and ablative processes [ 11 , 12 ].…”