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Published on: February 10, 2014
Importance of Ca(2+) modifications for osseointegration of smooth and moderately rough anodized titanium implants - a
Victoria Fröjd1, Ann Wennerberg, Victoria Franke Stenport
1Department of Prosthodontics, Faculty of Odontology, Malmo University, Malmo, Sweden. victoria.frojd@biomaterials.gu.se
Background:
Incorporation of Ca(2+) into the titania of anodized titanium surfaces has been found to enhance osseointegration. It provides a stable surface when the ions are incorporated into the oxide layer during the anodizing process. The Ca(2+) may suggestively be prominent sites for mineral induction, attract proteins, and catalyze intracellular cascades.
Purpose:
The aim of the present study was to evaluate the osseointegration of smooth (S(a) < 0.5 µm) and moderately rough (S(a) 1.0-2.0 µm) commercially pure titanium implants, with and without Ca(2+) , in order to reflect on the importance of surface chemistry in relation to topography.
Materials And Methods:
Anodized implants with (OxCa) or without Ca(2+) (Ox), blasted implants (Bl), and blasted anodized implants, with (BlOxCa) or without Ca(2+) (BlOx), were inserted in rabbit femur and tibia. The implant surfaces were characterized using interferometry, scanning electron microscopy, and X-ray photoelectron spectroscopy prior to implant installation. Removal torque (RTQ) measurements were executed on all implants after a healing period of 12 weeks. The implants were, thereafter, removed en bloc with surrounding tissues and prepared for histological evaluations.
Results:
RTQ measurements of tibial implants revealed significantly higher values for BlOxCa implants (90.7 ± 23.3 Ncm) compared to OxCa (64.6 ± 18.2 Ncm) and BlOx implants (69.7 ± 17.5 Ncm) (p = 0.029). Ca(2+) modification of smooth implants placed in the femur did not reveal any differences.
Conclusion:
Ca(2+) modification of smooth implants resulted in similar interfacial shear strength as moderately rough implants and Ca(2+) modification of moderately rough implants demonstrated the significantly strongest interfacial shear strength when placed in rabbit tibia. This possibly demonstrated surface chemistry compensating for lesser roughness.

