Implant stability measurement of delayed and immediately loaded implants during healing.
BACKGROUND The introduction of resonance frequency analysis (RFA) as a commercially available technique has made it possible to measure implant stability in implant stability quotient (ISQ) units at any time during the course of implant treatment and loading. However, no information on normal ISQ levels can be found in the literature. PURPOSE The aim of this pilot study was to measure the stability of clinically successful implants in partially edentulous patients after 1 year of loading and to study the influence of jaw, anterior/posterior position, implant length, and marginal bone level on implant stability. MATERIALS AND METHODS Fourteen partially edentulous patients previously treated with 45 implants were subjected to clinical and radiographic evaluations and RFA measurements using Osstell (Integration Diagnostics, Savedalen, Sweden) after 1 year of loading. RESULTS All 45 implants were stable, and implant stability levels were in the range of 57 to 82 ISQ units with a mean of 69 +/- 6.5 ISQ after 1 year of loading. Mandibular implants were more stable than were maxillary ones. There were no differences between anterior and posterior implants. No correlation could be found between implant length and stability. Only minor marginal bone resorption was observed. CONCLUSIONS The results from this limited material showed that successfully integrated implants have ISQ levels from 57 to 82 ISQ with a mean of 69 ISQ after 1 year of loading. Mandibular implants are more stable than are maxillary ones. High implant stability can be achieved with short implants and placement in posterior regions.