Marginal bone loss around implants with platform-switched Morse-cone connection: a radiographic cross-sectional study.

Abstract

The aims of the present cross-sectional study are to evaluate the bone remodeling around Morse-cone implants placed subcrestally 1year after loading and the prevalence of bone loss >0.5mm after at least 3years of loading. Subjects who underwent a radiographic check in 2013 with implants that had been in function for at least 3years were considered for inclusion. The study population comprised of 145 subjects with a total of 523 implants. At the moment of insertion, all the implants were placed subcrestally from 1 to 3mm as clinically measured. Radiographs taken at baseline, that is 1year after loading (T0), and at the follow-up visit in 2013 (T1) were examined. The distance between the rim of the implant and the marginal bone level at mesial and distal aspects of each implant was determined and the mean bone loss calculated. In the total sample, the mean bone loss occurred between baseline and 2013 examination was 0.42±0.77mm; at T1 424 implants presented the marginal bone level at the implant rim (78) or above it (346). On the other hand, 99 implants presented the rim above the bone crest. Fifty-one implants that at T1 presented the rim above the bone crest, and that between T0 and T1 had lost at least 0.5mm, were considered losers: 10 implants lost up to 0.5mm, 11 lost from 0.6 to 1mm, 16 lost from 1.1 to 2mm, and 14 lost more than 2mm of bone. On a subject basis, 34 subjects (group A) with a total of 200 implant sites presented loser implants, while 111 subjects (group B) with 323 implants displayed non-loser implants. Within the limits of a cross-sectional study, the results show that Morse-cone implants placed subcrestally in the vast majority of cases (89.9%) are able to maintain the bone crest at level of the rim or above it 1year after loading. The incidence of loser sites (bone loss >0.5mm) after at least 3years of follow-up is 9.7% at implant level and 23.5% at patient level.