Comparison of the Effects of Phosphate-Coated and Sandblasted Acid-Etched Titanium Implants on Osseointegration: A Microcomputed Tomographic Examination in the Canine Model

Purpose: This study tested the effects of phosphate treatment of titanium on bone volume fraction (BV/TV) at 30 to 60 µm from the implant surface using microcomputed tomography to analyze the mineralized tissue. Materials and Methods: Electrolytically phosphated (50/100 volts [T1/T2]) or nonphosphated 3.3- × 8-mm titanium implants (C) with sandblasted acid-etched surfaces were placed in 40 mandibular sites in five foxhounds 6 weeks after the extraction of the premolars. After 4 weeks, the animals were sacrificed, and BV/TV was analyzed using microcomputed tomography. Results: The mean BV/TV (± standard deviation) of the control implants was 31.4% ± 15.3% (range, 10.9% to 55.3%). For the T1 implants, a mean BV/TV of 38.4% ± 10.7% (range, 21.6% to 57.3%) was seen, and for T2 implants, the mean BV/TV was 40.3% ± 15.1% (range, 16.5% to 61.1%). Mean BV/TV values for the groups were not significantly different. For all groups (C, T1, and T2), there were no significant differences in BV/TV at the most coronal slices. For all groups, there was a positive slope showing more bone apposition as the slices moved from coronal to apical. The T2 group showed significantly increased mineralized tissue moving from the coronal to the apical section of the implant, compared to the control and T1 implants. Conclusion: Access to better blood supply and bone cells from the marrow spaces in the apical regions may lead to a better trabecular bone response. Increased mineralized tissue apposition may allow for accelerated loading and more predictable implant placement in sites with poorquality bone or patients with compromised bone healing. Parole chiave: acid etching, dental implant, microcomputed tomography, osseointegration, phosphate, surface properties, titanium