Resonance frequency analysis of stability on ITI implants with osteotome sinus floor elevation technique without grafting: A 5-month prospective study

Abstract

Objective: The aim of the present study was to (1) monitor the stability changes of ITI implants placed in atrophic posterior maxillary ridges with osteotome sinus floor elevation (OSFE) without grafting during the first 5 months of healing utilizing resonance frequency analysis (RFA) and (2) determine the factors that affect the implant stability quotient (ISQ) at placement and healings. Material and methods: Forty-two ITI implants were placed in the posterior maxilla in 32 patients with OSFE without bone grafting. The residual vertical bone height ranged from 4 to 8 mm (average 6.36 mm). Bone type was classified into one to four groups according to the Lekholm and Zarb index. ISQ was tested on the day of surgery and consecutively at 2, 4, 6, 8, 12, 16, and 20 weeks by RFA. Results: The 40 osseointegrated implants represented a survival rate of 95.2%. All the 40 implants achieved good primary stability and reached a comparably high stability at 16 weeks postoperation with a dip between 2 and 6 weeks in the stability curve. There was no significant difference of ISQ between type3 and type4 bone at implant placement and follow-up. The mean ISQ and its changing pattern did not demonstrate a statistically significant difference according to the pretreatment vertical bone height and implant length. Conclusions: The findings of this study indicated that uneventful osseointegration may be predictable applying OSFE alone with no grafting in atrophic posterior maxilla. Residual bone height (RBH), implant length, and bone type did not seem to affect the implant stability in this clinical situation. © 2008 Blackwell Munksgaard.