Osseointegration of titanium implants with SLAffinity treatment: a histological and biomechanical study in miniature pigs.
OBJECTIVE
Electrochemical oxidation following sandblasting and acid-etching (SLA) treatment has received interest as a surface modification procedure for titanium (Ti) implants (denoted as an SLAffinity surface); however, little information is available on its impacts on the in vivo performance of SLAffinity-Ti implants. The present study evaluated the osseointegration and biomechanical bone-tissue response to SLAffinity-Ti implants with micro- and nanoporous oxide layers.


METHODS
The interaction between blood and the tested implants was examined. In total, 144 implants with the following surfaces were used: a standard machined (M-Ti), an SLA-Ti, and an SLAffinity-Ti surface. For each animal, four implants (one M-Ti, one SLA-Ti, and two SLAffinity-Ti) were inserted into the mandibular canine-premolar area for histomorphometric observations and another four implants were inserted into the flat surface on the anteromedial aspect of the rear tibia for removal torque (RT) tests. After 2, 4, and 8 weeks of implantation, histomorphometric and RT tests were conducted.


RESULTS
Interactions between blood and implants were better for implants with the SLAffinity-Ti surface. RT tests showed a significant improvement in fixation strength for SLAffinity-Ti implants (84.5 ± 8.7 N-cm) after 8 weeks compared to M-Ti (62.95 ± 11.5 N-cm) and SLAffinity-Ti (76.1 ± 6.6 N-cm) implants. A histological evaluation showed that osseous integration had occurred with all implants after 8 weeks. SLAffinity-Ti implants exhibited 28.5 ± 6.2 % bone-to-implant contact (BIC) at 2 weeks and 84.3 ± 8.1 % at 8 weeks. M-Ti implants exhibited BIC levels of 17.0 ± 5.4 and 76.5 ± 6.3 %, whereas SLA-Ti implants exhibited BIC levels of 28.5 ± 6.2 and 81.1 ± 8.4 % at corresponding time intervals. In terms of the peri-implant bone area (BA), values for SLAffinity-Ti implants ranged from 29.5 ± 4.1 to 88.3 ± 3.0 %. For M-Ti implants, values ranged from 20.3 ± 5.5 to 81.7 ± 4.2 %. For SLA-Ti implants, values ranged from 23.0 ± 3.5 to 84.0 ± 3.6 %.


CONCLUSIONS
Electrochemical oxidation increased the oxide layers and improved the blood interaction with SLAffinity-Ti implants, resulting in significantly higher bone apposition with the SLAffinity-Ti implants after 2 and 8 weeks of healing. An increase in resistance for the RT of SLAffinity-Ti implants over the 8-week healing period was also observed.


CONCLUSIONS
The use of SLAffinity-Ti implants has potential for improvement of early osseointegration.
School of Dentistry, Taipei Medical University, Taipei, 110, Taiwan.|Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei, 110, Taiwan.|Research Center for Biomedical Implants and Microsurgery Devices, Taipei Medical University, Taipei, 110, Taiwan.
Keng-Liang
KL
Ou
School of Dentistry, Taipei Medical University, Taipei, 110, Taiwan.
Heng-Jui
HJ
Hsu
School of Dental Technology, Taipei Medical University, Taipei, 110, Taiwan.
Tzu-Sen
TS
Yang
School of Dentistry, Taipei Medical University, Taipei, 110, Taiwan.|Department of Dentistry, Taipei Medical University Hospital, Taipei, 110, Taiwan.
Yun-Ho
YH
Lin
School of Dentistry, Taipei Medical University, Taipei, 110, Taiwan. endo11@tmu.edu.tw.|Department of Dentistry, Sijhih Cathay General Hospital, New Taipei, 221, Taiwan. endo11@tmu.edu.tw.
Chin-Sung
CS
Chen
School of Dental Technology, Taipei Medical University, Taipei, 110, Taiwan. apon@tmu.edu.tw.
Pei-Wen
PW
Peng
D000134:Acid Etching, Dental; D000818:Animals; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003775:Dental Polishing; D020007:Implants, Experimental; D016348:Osseointegration / Q000502:physiology*; D016062:Porosity; D013499:Surface Properties; D013552:Swine; D013556:Swine, Miniature; D013977:Tibia / Q000601:surgery*; D014025:Titanium / Q000737:chemistry; D019415:Torque
D015921:Dental Implants; D014025:Titanium
Nanoporous layer; SLAffinity-Ti; TiO2