Mechanical stability of immediately loaded implants with various surfaces and designs: a pilot study in dogs.
OBJECTIVE
Immediate loading is among the most innovative techniques in implant therapy today. This pilot study investigates the biomechanical outcome of various designs and surfaces that claim to shorten implant treatment.


METHODS
In each quadrant of two mongrel dogs, four different implants were used for immediate loading. The following implants were placed 3 months after tooth extraction: screw with low thread profile and anodic oxidized surface (LPAOS), solid screw with wide thread profile and titanium plasma spray coating (WPTPS), screw with low profile and hybrid design of double-etched and machined surface (LPHES), and screw with two thread profiles and a sandblasted and acid-etched surface (DTSAE). The insertion torque of each implant was above 35 Ncm. Resonance frequency analysis was performed after implant placement and again after sacrifice. Additionally, the removal torque and the amount of embedded titanium particles in the peri-implant bone were measured.


RESULTS
All 16 prostheses were functional after a 5-month loading period. The highest mean removal torque values were recorded with WPTPS implants (24.4 Ncm/mm), followed by DTSAE implants (22.3 Ncm/mm) and LPAOS implants (18.7 Ncm/mm); the lowest score was obtained by LPHES (12.0 Ncm/mm). The ISQ values increased between the time of surgery and recall for all systems on average, but a significant positive correlation was found for DTSAE only. Significantly higher amounts of titanium were found in the surrounding bone with WPTPS (0.76%) and LPAOS (0.41%) in comparison with DTSAE (0.10%) and LPHES (0.03%).


CONCLUSIONS
Immediate loading is possible with various designs and surfaces if high primary stability can be achieved during implant placement.
Neugebauer
Jörg
J
Interdisciplinary Department of Oral Surgery and Implantology, Department of Craniomaxillofacial and Plastic Surgery, University of Cologne, Köln, Germany. Joerg.neugebauer@uk-koeln.de
Weinländer
Michael
M
Lekovic
Vojislav
V
von Berg
Karl-Heinz Linne
KH
Zoeller
Joachim E
JE
D000704:Analysis of Variance; D000818:Animals; D015519:Bone Density; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D020878:Device Removal; D004285:Dogs; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D016348:Osseointegration; D010865:Pilot Projects; D013314:Stress, Mechanical; D013499:Surface Properties; D019415:Torque
D015921:Dental Implants