Immediate Non-Occlusal Loading vs. Early Loading in Partially Edentulous Patients Testori T, Bianchi F, Del Fabbro M, Szmukler-Moncler S, Francetti L, Weinstein RL. Practical Procedures & Aesthetic Dentistry. 2003;15:787–794.
Immediate loading and early loading protocols have recently received much attention in an effort to shorten overall treatment times for dental implant therapies. To investigate the predictability of such treatment regimens, the current study enrolled 32 partially edentulous patients requiring short-span fixed partial prostheses (FPP) supported by at least 2 implants. Edentulous spaces were located in anterior and posterior regions of both the maxilla and mandible. Patients were randomly allocated to 2 groups. In the immediate loading (IL) group, provisional short-span FPPs were placed within 24 hours of implant surgeries. The provisional FPPs were adjusted to have no direct occlusal contacts (200-μm articulating paper). Definitive prosthodontic procedures were initiated 2 months later for posterior restorations and 6 to 9 months later in aesthetically demanding areas or in immediate postextraction situations. In the early loading (EL) group, implants were placed using a 1-stage (nonsubmerged) surgical protocol. Provisional FPPs were placed 8 weeks after implant surgeries. Unfortunately, this report is unclear regarding the occlusal scheme developed on the provisional restorations and the timing of definitive restorative procedures in the EL group.
Variables monitored included success rate, implant form (cylindrical threaded vs. tapered threaded), bone quality (dense, normal, or soft), initial implant stability using insertion torque values (20–30 Ncm, 30–40 Ncm, or 40–50 Ncm), and implant stability using resonance frequency analysis. All implants in the IL group demonstrate at least 30 Ncm of insertion torque. Patient in the IL group were instructed to maintain soft diets and masticate away from the implant sites for 8 weeks. Data collection was accomplished during regular intervals for up to 2 years. Digital, nonstandardized, longitudinal, periapical radiographs were compared using image analysis software.
Clinically acceptable success rates were calculated for both IL and EL protocols (96.15% and 97.96%, respectively). Mean crestal bone loss at 18 months was 1.1 mm for IL and 0.8 mm for the EL group. This difference was not statistically significant. Notable was the finding that ISQ (the output value from resonance frequency analysis) at implant installation was 27.4% greater for tapered implants as compared with cylindrical implants. Because primary implant stability is currently believed to be an important factor in overall implant success, the current resonance frequency results suggest that the use of tapered implants could be advantageous when considering IL protocols.
Although the present results appear promising, authors cautioned that further investigations and long-term evaluations are necessary to confirm findings.