QUANTITATIVE HISTOMORPHOMETRIC DESCRIPTION OF IMPLANT ANCHORAGE FOR 3TYPES OF DENTAL IMPLANTS FOLLOWING 3 MONTHS OF HEALING IN BABOONS

Important to the understanding of the dynamics associated with dental implant anchorage over time is a knowledge of the supporting anatomy f or common endosseous implants prior to being placed into function. Thi s study followed 20 screw-shaped dental implants placed in edentulated (2 months' healing time) posterior jaws of five adult female baboons. Implants made of three biomaterials were placed and allowed to heal f or 3 months prior to processing for evaluation. Percentage integration and bone area data from six horizontal sections along the entire leng th of each implant were collected and analyzed for differences between jaws, implant biomaterials, jaw/biomaterial, and sections of the impl ants (ANOVA, pairwise comparison using LSM with Bonferroni adjustment) . The results indicated that overall mean percentage integration was 4 6.5 and mean percentage bone area was 39.9. Maxillary and mandibular d ifferences for both parameters were statistically different (integrati on: maxillary = 38.1%, mandibular = 56.7%; bone area: maxillary = 35.8 %, mandibular = 44.9%; both were significant at the P < .05 level). Th e biomaterial analyses revealed significant differences for percentage integration between the metal implants and the hydroxyapatite-coated implant (commercially pure titanium = 39.1%, titanium-aluminum-vanadiu m = 40.0%, hydroxyapatite-coated = 61.5%), but no such difference was noted for percentage bone area (commercially pure titanium = 38.8%, ti tanium-aluminum-vanadium = 38.9%, hydroxyapatite-coated = 42.3%). Disc ussion of the relative importance of the two parameters highlights the fact that resistance to functional loads requires establishing and th en maintaining an adequate volume of bone, which may have a functional ly specific structure based on the mechanical properties of the local jaw environment.