Ih. Orenstein et al., Factors affecting implant mobility at placement and integration of mobile implants at uncovering, J PERIODONT, 69(12), 1998, pp. 1404-1412
THIS STUDY EXAMINED 1) FACTORS that contributed to implant stability at pla
cement and 2) the likelihood for an implant that was mobile at placement to
osseointegrate. Eighty-one (3.1%) of 2,641 implants placed by the Dental I
mplant Clinical Research Group between 1991 and 1995 were found to be mobil
e at placement. Seventy-six (93.8%) of the 81 mobile implants were integrat
ed at uncovering compared to 97.5% for the 2,560 immobile implants. Variabl
es that influenced mobility at placement included patient age, implant desi
gn and material, anterior-posterior jaw location, bone density, and use of
a bone tap. Hydroxyapatite (HA)-coated implants were slightly more likely t
o be mobile at placement (P = 0.324) than non-hydroxypatite (HA)coated impl
ants. Of the 54 HA-coated implants that were mobile at placement, ail (100%
) integrated, while only 17 (81.5%) of the 22 mobile non-HA-coated implants
integrated (P = 0.003). Mean electronic mobility testing device values (PT
Vs) at uncovering for all implants mobile or immobile at placement that int
egrated were -2.9 and -3.6 respectively. PTVs for HA-coated implants that w
ere mobile (-3.5 PTV) or immobile (-4.0 PTV) at placement differed by 0.5 P
TV, whereas non-HA-coated implants exhibited a greater difference of 1.2 PT
Vs at uncovering. HA-coated implants, regardless of mobility at placement,
integrated more frequently and exhibited greater stability than non HA-coat
ed implants.