A histological evaluation of a functional endosseous, porous-surfaced, titanium alloy dental implant system in the dog.

We have previously reported the clinical and radiographic findings of a trial in dogs of a new dental implant system after a functional period of eight months. The present report consists of the corresponding qualitative and quantitative histological data. The implant system was fabricated from Ti-6A1-4V and employed a porous-surfaced configuration to achieve implant fixation by bone ingrowth. A similar porous surface was used on the apical 1/3 of the transgingival collar in an attempt to gain ingrowth and attachment of gingival connective tissue. The qualitative histological data confirmed that while such attachment to the collar did occur for some implants, in the majority of implants (22 of 32) the porous region of the collar became contaminated with bacterial plaque, resulting in implant failure (four implants) or suggesting future implant failure (18 implants). Statistical analyses of the quantitative histological data indicated that there were no significant differences in surface contact of bone with the middle third of the porous implant surface (CLF) when initial healing interval (four or eight weeks), implant location, or aspect of implant (buccal vs. lingual vs. mesial vs. distal) were compared. However, comparison of the current group of functional implants with an earlier group of similarly implanted non-functional implants indicated that function produced a highly significant increase in CLF.