Effect of surface topology on the osseointegration of implant materials in trabecular bone

Abstract

The importance of surface topology and implant material composition on osseointegration in trabecular bone was investigated using three commericially used implant materials and surface-texturing procedures which included blasting, high temperature acid etching, and hydroxyapatite (HA) coating. Surface roughness and spacing parameters were measured for each implant group with a laser interferometric profilometer. Cylindrical implants were press-fit into trabecular bone sites in the knee of mature miniature pigs. After 12 weeks in situ, osseointegration was evaluated by (1) mechanical pushout tests to measure bone-implant interface strength and (2) quantitative morphometric measurements of the percent implant surface covered by bone. We found that HA-coated implants showed superior osseointegration in terms of both pushout failure load and surface coverage by bone measurements. An excellent correlation (r2 = .90) was found between the average roughness of the implant surface and pushout failure load. New methods for altering the local topologic and/or chemical state of the implant surface (i.e., by acid etching) may provide an important new avenue of research for improving the osseointegrative properties of orthopedic materials.

Influence of Temperature and Acid Etching Time on the Superficial Characteristics of Ti

“…Although a good correlation between increased R a (bi-dimensional correlate of the three-dimensional S a ) and stronger anchorage 5,17,20 was observed in the literature, one cannot speculate on their biological performance until their bone interlocking capacity is demonstrated. It turns out that clinical implications cannot be drawn by relying on roughness-descriptive parameters alone 4 .…”

“…As the etching temperature was raised, surface irregularities became deeper, and the mean S a and S dr increased. Some studies have demonstrated that increases in the numerical surface roughness of an implant enhance biomechanical anchorage in bone, as determined by torque removal tests 16 and resistance to push-out forces 17 . These studies showed a tendency toward an increase in bone contact, and resistance to removal, with an increasing numerical implant surface roughness.…”

Preparation and biological evaluation of hydroxyapatite-coated nickel-free high-nitrogen stainless steel

“…In the biological evaluation over 32 weeks using transcortical plug model of adult mongrel dogs, Thomas et al [62] demonstrated that the use of the HAp-coated implant significantly increased mechanical strength at the implant-bone interface because of the direct mineralization onto the roughened surface. In the evaluation over 12 weeks using mature miniature pigs, Wong et al [63] also demonstrated that the roughened surface possessed the significant osseointegration property because of the higher surface coverage by bone. Therefore, HAp-coated HNS is likely to be an effective bioactive material for enhancing osteogenesis and osseointegration.…”

Mg-Containing Hydroxyapatite Coatings Produced by Plasma Electrolytic Oxidation of Titanium

“…To expand the successful applications as dental and orthopedic implants several methods are used to modify the titanium surface with the objective of improving its bioactivity. In this context, great improvement in biological properties, consequently reducing the rejection of implants 6 , has been achieved with calcium phosphate coatings.…”