Biomechanical evaluation of endosseous implants at early implantation times: a study in dogs.
OBJECTIVE
This study tested the null hypothesis that differences in surgical instrumentation, macrogeometry, and surface treatment imposed by different implant systems do not affect early biomechanical fixation in a canine mandible model.


METHODS
The lower premolars of 6 beagle dogs were extracted and the ridges allowed to heal for 8 weeks. Thirty-six (n = 12 each group) implants were bilaterally placed, remaining for 1 and 3 weeks in vivo. The implant groups were as follows: group 1, Ti-6Al-4V with a dual acid-etched surface with nanometer scale discrete crystalline deposition (Nanotite; Certain Biomet-3i, West Palm Springs, FL); group 2, Ti-6Al-4V with a titanium oxide-blasted fluoride-modified surface chemistry (Osseospeed 4.0 S; Astra Tech, Mölndal, Sweden); group 3: Ti-6Al-4V with a bioceramic microblasted surface (Ossean; Intra-Lock International, Boca Raton, FL). Following euthanasia, implants were torqued to interface failure and histologically evaluated. General linear modeling (ANOVA) at 95% level of significance was performed.


RESULTS
Histology showed that interfacial bone remodeling and initial woven bone formation were observed around all implant groups at 1 and 3 weeks. Torque values were significantly affected by time in vivo, implant group, and their interaction (P = .016, P < .001, and P = .001, respectively). Regarding torque values, group 3, group 2, and group 1 ranked highest, intermediate, and lowest, respectively.


CONCLUSIONS
Early biomechanical fixation at 1 and 3 weeks was affected by surgical instrumentation, macrogeometry, and surface treatment present for one of the implant systems tested. The null hypothesis was rejected.
Coelho
Paulo G
PG
Department of Biomaterials and Biomimetics, New York University, New York, NY 10010, USA. pgcoelho@nyu.edu
Granato
Rodrigo
R
Marin
Charles
C
Bonfante
Estevam A
EA
Freire
Jose N O
JN
Janal
Malvin N
MN
Gil
Jose N
JN
Suzuki
Marcelo
M
D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D016723:Bone Remodeling; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D004285:Dogs; D016014:Linear Models; D016348:Osseointegration; D013499:Surface Properties; D013997:Time Factors; D019415:Torque
D015921:Dental Implants