Morphologic and nanomechanical properties of in vivo bone tissue growth of a new bioactive solgel wollastonite coatings on stainless steel implants

JOSEFINA BALLARRE; SELTZER ROCIO; EMIDGIO MENDOZA; JUAN CARLOS ORELLANO; YIU-WING MAI; CLAUDIA GARCIA; SILVIA CERE

MATERIALS SCIENCE & ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011 vol. 31 p. 545 - 552

0928-4931

Metals are the most widely used materials in orthopaedic and dental implants due to their excellentmechanical properties. However, they do not bond naturally with mineralized bone. Further, they can releasemetallic particles that may finally result in the removal of the implant. There are two strategies to avoid thesedrawbacks: one is to protect the metallic implant with a biocompatible coating and the other is to addbioactive particles to enhance implant fixation to the existing bone. In this work, surgical grade stainless steelimplants coated with tetraethoxysilane (TEOS)–methyltriethoxysilane (MTES) and 10 wt.% of commercialwollastonite particles were implanted in the Hokkaido femur rats. Transversal sections of the tibia sampleswere examined with SEM, AFM, histological analysis and nanoindentation experiments in air and underphysiological conditions to characterize the hydroxyapatite deposits and the composition of the newlyformed tissue around the implant. The results showed no presence of harmful ions or metallic particles in thesurrounding tissues and that the coating promoted formation and growth of new bone in the periphery of theimplant, both in contact with the old bone (remodellation zone) and the marrow (new bone). The relativemechanical behavior of old, remodeled and new bone tissues obtained in air cannot be directly extrapolatedto live or in vivo-physiological response. This may be caused by the different degree of hydration and SBF/structure interaction among the three types of bones but these values are near the normal hydrated boneresponse.