A comparison of stability between delayed versus immediately loaded orthodontic palatal implants

Introduction: Control of anchorage is a fundamental problem in orthodontics. Conventional means of controlling anchorage are characterized by potential disadvantages and inconveniences: visibility, compliance dependence, risk of undesirable side effects, and injury. Titanium implants have evolved as a potential clinical alternative in overcoming the limits of conventional dental orthodontic anchorage. Methods: This project was designed as a prospective observational study on 20 patients whose treatment plans required maximum (stable) anchorage during orthodontic treatment. The patients received palatal implants (Institut Straumann AG, Waldenburg, Switzerland: length of implant 4-6 mm, diameter 3.3 mm), which were placed into the midpalate. The goal of this study was to evaluate if the implant could be loaded immediately, or if time should be allowed for integration. Patients were randomized into two groups; one group had their implants loaded immediately with a coil spring, and the second group remained nonloaded, with an annealed coil spring, for the 8-week experimental period. Measurement of implant stability was taken using resonance frequency analysis on both groups at the time of implant placement and at 8 weeks post-placement. Results: This study demonstrated that immediate loading of the Straumann orthodontic implant is possible, based on the clinical success observed in both groups. However, compared with the nonloaded group, the stability of the immediately loaded implant was significantly less at 8 weeks. The mean implant stability quotient (ISQ) of the nonloaded group was 38.7 kHz at baseline and 47.3 kHz after 8 weeks. The mean ISQ of the loaded group was 42.0 kHz at baseline and 38.4 kHz after 8 weeks. Statistical analysis showed a significant difference between the group that was loaded and the nonloaded group after 8 weeks (p < 0.05). Conclusion: Based on the results of this study, an unloaded healing period provides for increased stability of the implants compared with immediately loaded palatal implants.