CO₂ Laser Irradiation Positively Affects the Surface Energy of Rough Titanium Surfaces

Purpose: To investigate the free surface energy before and after CO₂ irradiation on rough titanium (Ti) surfaces. Materials and Methods: Sandblasted, large grit, acid-etched (SLA) implant surfaces were used for this study. Contact angle evaluations were performed for saline, albumin, and artificial blood using a contact angle goniometer at 25°C and 37°C (20 droplets in each group, 120 in total). The Ti disks were then irradiated with a CO₂ laser (10,600 nm) using a noncontact, defocused, 2-W continuous wave for 30 seconds. Contact angle measurements for saline, albumin, and artificial blood were evaluated immediately after irradiation (new 120 in total contact angle measurements) and compared with the measurements before laser irradiation. A paired t-test using SPSS statistics (IBM) was performed for 5 statistical significance level. Results: Lower numbers of contact angle measurements were found after CO₂ irradiation, and these changes were statistically significant (P < .05) for all groups, except for albumin at 25°C, as follows: saline at 25°C—(pre) 111.97°C± 13.67°C and (post) 79.29°C± 10.83°C (P < .0001); albumin at 25°C—(pre) 89.04°C± 12.02°C and (post) 83.29°C± 20.71°C (P = .297); blood at 25°C—(pre) 97.79°C± 14.44°C and (post) 86.29°C± 10.82°C (P = .019); saline at 37°C—(pre) 104.12°C± 13.138°C and (post) 92.66°C± 4.777°C (P = .001); albumin at 37°C—(pre) 89.04°C± 12.02°C and (post) 83.29°C± 20.71°C (P = .297); blood at 37°C—(pre) 80.42°C± 19.00°C and (post) 58.62°C± 24.34°C (P = .012). Conclusions: CO₂ laser irradiation in general positively affected the wettability and hydrophilicity of rough Ti SLA surfaces.