Keywords
Clinical study, immediate loading, ISQ, implant stability, ITI implants, primary stability, resonance frequency analysis.
Abstract
The aim of this clinical study was (1) to evaluate Osstell as a diagnostic tool capable of distinguishing stable ITI implants from mobile implants, (2) to assess a threshold value of the implant stability quotient (ISQ) measured at the time of placement (ISQitv) that could predict osseointegration, and (3) to compare the predictive ISQitv values of immediately loaded (IL) implants and implants loaded after 3 months (delayed loading, DL).
Two groups of patients were included: 18 patients received 63 implants under immediate loading, and 18 patients were treated with 43 implants under delayed loading. ISQ measurements were recorded at placement and at 1, 2, 4, 6, 8, 10, and 12 weeks.
All implants passed the 1-year loading control. Two implants failed: one DL implant with an ISQi of 48 and one IL implant with an ISQi of 53. Resonance frequency analysis (RFA) was not able to reliably identify mobile implants. However, implant stability could be reliably determined for implants with an ISQ ≤ 47.
After 1 year of loading, all DL implants with an ISQi ≤ 49 and all IL implants with an ISQi ≤ 54 achieved and maintained osseointegration. After 3 months, implants with an ISQi ≥ 60 showed an increase in stability. Those with an ISQi between 60 and 69 experienced a decrease in stability for 8 weeks before returning to baseline values. Implants with an ISQi < 69 showed a decrease in stability during the first 4 weeks before stabilizing.
Although preliminary, these data may help clinicians choose between different loading protocols and selectively monitor implants during the healing phase.
