Interface shear strength of titanium implants with a sandblasted and acid-etched surface: A biomechanical study in the maxilla of miniature pigs

The purpose of the present study was to evaluate the interface shear streng th of unloaded titanium implants with a sandblasted and acid-etched (SLA) s urface in the maxilla of miniature pigs. The two best documented surfaces i n implant dentistry, the machined and the titanium plasma-sprayed (TPS) sur faces served as controls. After 4, 8, and 12 weeks of healing, removal torq ue testing was performed to evaluate the interface shear strength of each i mplant type. The results revealed statistically significant differences bet ween the machined and the two rough titanium surfaces (p < .00001). The mac hined surface demonstrated bean removal torque values (RTV) between 0.13 an d 0.26 Nm, whereas the RTV of the two rough surfaces ranged between 1.14 an d 1.56 Nm. At 4 weeks of healing, the SLA implants yielded a higher mean RT V than the TPS implants (1.39 vs. 1.14 Nm) without reaching statistical sig nificance. At 8 and 12 weeks of healing, the two rough surfaces showed simi lar mean RTVs. The implant position also had a significant influence on rem oval torques for each implant type primarily owing to differences in densit y in the periimplant bone structure. It can be concluded that the interface shear strength of titanium implants is significantly influenced by their s urface characteristics, since the machined titanium surface demonstrated si gnificantly lower RTV in the maxilla of miniature pigs compared with the TP S and SLA surfaces. (C) 1999 John Wiley & Sons, Inc.