Evaluation of the effect of diode laser application on the hydrophilicity, surface topography, and chemical composition of titanium dental implant surface.

Abstract

Attempts have been made to decontaminate the implant surface by using diode lasers. However, the parameters that provide efficient decontamination without altering the topography or surface characteristics of titanium implants are still unclear. The aim of the present study was to evaluate the effect of altering the power of diode laser (940nm) application on the hydrophilicity, surface topography, and chemical composition of sandblasted, large grit, acid-etched (SLA) treated titanium alloy implant surface. Thirty-six SLA-treated titanium discs (Dentis Co., Ltd.) were used in this study. The hydrophilicity of all discs was measured by using a contact angle goniometer (190 CA; Rame-hart Co, Ltd). Discs were randomly divided into four groups (n = 9 each) based on the power of the diode laser used. Group I (control, no lasing group), group II: treated with 1W power, group III: 2W power, and group IV: 3W power. The chemical composition of the SLA discs was evaluated by using energy dispersive x-ray spectroscopy (EDX) before laser application. Hydrophilicity was reevaluated after the application of laser irradiation. The surface topography of all discs was examined. Changes in the chemical composition of the titanium discs were investigated following the lasing procedure. Morphometric analysis of the surface area (μm2 ) of the indentations created following laser application was also evaluated. Data were collected and the Shapiro-Wilk test of normality was used. Comparisons between the four study groups were done by using the Kruskal-Wallis test, while that to evaluate the morphometric analysis of the surface area was done by using One-way ANOVA (P<0.05). The average contact angle of the drop of distilled water to the SLA discs significantly decreased after laser treatment (P<0.05). The largest contact angle was measured in the control group, followed by the 1W group, and the 2W group. The smallest angle was measured in the 3W group. Considerable surface alterations such as melting and flattening were observed on examination of the surface topography of the 3W group followed by the 2W group. The least changes were observed in association with the 1W group in comparison to the control group. The EDX analysis showed the appearance of peaks of the oxygen and carbon elements after the lasing procedure with the highest percentage in the 3W group. The average of the surface area of the created indentations significantly increased with increasing the power of the diode laser used (P<0.05). The application of diode laser (940nm) with 2W and 3W powers significantly altered the hydrophilicity, the surface topography, and the chemical composition of titanium discs. Diode laser (940nm) with 1W power can be safely used on SLA titanium implant surfaces with no damaging effect on the surface topography or hydrophilicity.