Use of Er:YAG laser to improve osseointegration of titanium alloy implants--a comparison of bone healing.
The objective of this study was to compare the osseointegration of implants in rats in sites prepared with an Er:YAG laser with osseointegration in sites prepared using a conventional drill by assessing the percentage of bone-implant contact (BIC). Osteotomies were prepared with an Er:YAG laser in the tibiae of 18 rats (the test group) and drill-prepared with a 1.3-mm-wide surgical implant drill at 1,000 rpm with simultaneous saline irrigation in the tibiae of another 18 rats (the control group). Acid-etched titanium alloy implants (2 x 8 mm) were placed in the tibiae, engaging the opposite cortical plate. The Er:YAG laser was used with a regular handpiece and water irrigation (spot size, 2 mm; energy per pulse, 500 to 1,000 mJ; pulse duration, 400 ms; and energy density, 32 J/cm2). Nine animals from each group were sacrificed after 3 weeks of unloaded healing; the remainder were sacrificed after 3 months. The tissues were fixed and prepared for histologic and histomorphometric evaluation. Statistical analysis showed significant differences between the 2 groups at both 3 weeks and 3 months. After 3 weeks of unloaded healing, the mean BICs (+/- SD) were 59.48% (+/- 21.89%) for the laser group and 12.85% (+/- 11.13%) for the control group. Following 3 months of unloaded healing, the mean BICs (+/- SD) were 73.54% (+/- 11.53%) for the laser group and 32.6% (+/- 6.39%) for the control group. Preparation of the implant sites with the Er:YAG laser did not damage the interface; the healing patterns presented were excellent. Based on the results of this study, it may be concluded that the Er:YAG laser may be used clinically for implant site preparation with good osseointegration results and bone healing and with a significantly higher percentage of BIC compared to those achieved with conventional methods.