Effects of Er:YAG laser irradiation on rough titanium surface properties and osteoblast-like cell responses in the absence or presence of carbonate apatite.

OBJECTIVES

This study investigated the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation on rough titanium surface properties and osteoblast-like cell responses in the absence or presence of carbonate apatite (CO₃Ap) as a bone substitute.

DESIGN

Rough titanium plates were prepared as nonirradiated or irradiated by an Er:YAG laser using clinically applicable parameters. The surface morphology was examined through scanning electron microscopy (SEM), and the wettability and surface roughness (Ra) were measured. MC3T3-E1 cells were cultured on titanium plates in the absence or presence of CO3Ap. Cell viability was assessed on days 1 and 5 after cell seeding, and alkaline phosphatase (ALP) activity was assessed on days 1 and 7. Calcium ion (Ca²⁺) concentrations were measured in three cell-free solutions.

RESULTS

Er:YAG irradiation produced no apparent SEM-detectable surface morphological changes while improving surface wettability and increasing Ra. Cell viability was generally higher in the presence of CO₃Ap, and the highest value was observed on irradiated titanium in the presence of CO₃Ap on day 5. ALP activity was higher in the presence of CO₃Ap on day 7 and was also increased by Er:YAG irradiation in the absence of CO3Ap. CO₃Ap modulated Ca²⁺ concentration in a solution-dependent manner.

CONCLUSIONS

Er:YAG irradiation improved the wettability and increased the surface roughness without any SEM-detectable morphological changes. In the presence of CO₃Ap as a bone substitute, Er:YAG-irradiated titanium surfaces may be compatible with osteoblast-like cell responses in vitro. Further studies are required to clarify the clinical relevance of this approach.