Journal of Dental Research, Vol 69, 1138-1145, Copyright © 1990 by International & American Associations for Dental Research Online Journals
A histological comparison in the dog of porous-coated vs. threaded dental implants
D. A. Deporter, P. A. Watson, R. M. Pilliar, M. L. Chipman and N. Valiquette
Medical Research Council Program in Dental Implantology, Faculty of Dentistry, University of Toronto, Ontario.
The histological findings of an 18-month trial, in the dog of a partially
porous-coated endosseous dental implant made of Ti-6Al-4V, with a truncated
conical shape, are described and compared with those for a cylindrical,
threaded, endosseous implant made of commercially pure Ti. Six beagle dogs
each received two porous-coated implants on one side of the mandible and
two threaded implants on the contralateral side. Each set of two implants
supported a two-unit fixed bridge for an 18-month functional period.
Methylmethacrylate sections of both the buccolingual and mesiodistal
aspects of each implant were examined qualitatively and by
computer-assisted morphometry. The morphometric measurements were used for
determination of the length of implant surface in direct contact with bone
on each aspect of each implant. The data were expressed both as an absolute
length and as a fraction of the maximum length available for contact
(contact length fraction or CLF). On the buccal and lingual aspects of the
implants, both the absolute lengths and CLF were significantly smaller for
the porous-coated design. For the mesial and distal aspects, the absolute
lengths and CLF were less for the porous-coated design, but the differences
were not significant. However, when the absolute contact length was related
to the corresponding vertical bone height, significant differences were
observed, the absolute contact length being greater for any given bone
height for the porous-coated design. Taken together, the data suggest that
shorter implants may be used with the porous-coated design.
