Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation.
BACKGROUND
The importance of the surface properties of implants for a successful osseointegration has been emphasized. It is generally known that bone response to implant surfaces is considerably related to the various surface properties.


OBJECTIVE
The purpose of this study was to investigate bone tissue reactions to multifactorial biocompatibility of the surface oxide of electrochemically oxidized titanium implants. The ultimate objective was to improve surface quality, resulting in enhancement of clinical outcomes of osseointegrated implants.


METHODS
Three different surface types of commercially pure titanium (c.p. Ti) implants were prepared. Turned implants were used for controls and test implants were prepared by the micro arc oxidation (MAO) method, either in sulphuric acid (S implants) or in phosphoric acid (P implants). Implants were inserted in the femur and tibia of 10 mature New Zealand White rabbits. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. The follow-up time was 6 weeks.


RESULTS
The mean peak values of the removal torque showed significant differences between control and test S implants (p =.022) but showed no significant differences between control and test P implants (p =.195) or between test S and test P implants (p =.457). In addition, the histomorphometric comparisons of the bone-to-metal contact around entire implants demonstrated 186% increase in S implants (p =.028) and 232% increase in P implants (p =.028) compared with the paired control groups. Quantification of the bone area in the threads did not show any significant differences.


CONCLUSIONS
The present results suggest that the primary mode of action in strong bone response to S implants is mechanical interlocking, and to P implants, it is biochemical interaction. It is possible that the phosphate groups in the titanium oxide of P implants provide potential chemical bonding sites for calcium ions and hydroxyapatite of the bone matrix during biologic mineralization. key words: bone responses, histomorphometry, oxidized implants, removal torque test, surface oxide properties
Department of Biomaterials/Handicap Research, Institute for Surgical Sciences, University of Gothenburg, Sweden. young-taeg@hkf.gu.se
Young-Taeg
YT
Sul
Carina B
CB
Johansson
Yunmo
Y
Kang
Dong-Gyun
DG
Jeon
Tomas
T
Albrektsson
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001857:Bone Matrix / Q000503:physiopathology / Q000648:ultrastructure; D001842:Bone and Bones / Q000503:physiopathology / Q000648:ultrastructure*; D015921:Dental Implants; D004563:Electrochemistry; D005260:Female; D005269:Femur / Q000503:physiopathology / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D010084:Oxidation-Reduction; D010756:Phosphoric Acids / Q000737:chemistry*; D011817:Rabbits; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D013464:Sulfuric Acids / Q000737:chemistry*; D013499:Surface Properties; D013977:Tibia / Q000503:physiopathology / Q000648:ultrastructure; D014025:Titanium / Q000737:chemistry*; D019415:Torque; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D015921:Dental Implants; D010756:Phosphoric Acids; D013464:Sulfuric Acids; C009495:titanium dioxide; D014025:Titanium; C033158:sulfuric acid