Ak. Roynesdal et al., A COMPARATIVE CLINICAL-STUDY OF 3 DIFFERENT ENDOSSEOUS IMPLANTS IN EDENTULOUS MANDIBLES, The International journal of oral and maxillofacial implants, 13(4), 1998, pp. 500-505
The purpose of this prospective study was to investigate the clinical
outcome and marginal bone resorption of three different endosseous imp
lants placed in the anterior mandibles of 15 elderly patients. Eleven
women and 4 men (ranging from 65 to 80 years, mean 71 years) had three
different endosseous implants placed in the anterior mandible; one ti
tanium plasma-sprayed cylinder implant (4-mm diameter), one titanium c
ylinder implant with hydroxyapatite coating (4-mm diameter), and one s
tandard threaded titanium implant (3.75-mm diameter). Three months lat
er, at the second-stage surgical procedure, ball abutments were connec
ted and an overdenture was placed. At 12, 24, and 36 months, marginal
bone resorption and Periotest values were recorded. None of the implan
ts was lost in this period. An analysis of valiance with repeated meas
urement was performed annually to test the existence of significant di
fferences between the implants. When differences appeared, paired t te
sts were used to identify which differences were significant. Bonferro
ni multipliers were used to adjust for multiple testing. When marginal
bone resorption was concerned, threaded titanium and hydroxyapatite-c
oated implants had significantly better scores than titanium plasma-sp
rayed cylinder implants. Periotest values for hydroxyapatite-coated im
plants were significantly better than test values for the other implan
ts after 2 years. After 3 years significance was obtained between hpdr
oxyapatite and screw-shaped implants only (P <.05). It was concluded t
hat titanium plasma-sprayed cylinder implants have a less favorable pr
ognosis than the other implants used in this study.