Immediate vs. conventional loading of palatal implants in humans

Abstract

To analyze the clinical performance and bone-to-implant contact (BIC) rate of two loading concepts on successfully healed and explanted palatal implants in humans. From 2000 to 2006, two independent groups of patients, requiring maximum anchorage, were treated. Group 1 (n=36) was subjected to immediate functional loading within the first 24 h after insertion while group 2 (n=40) received conventional implant loading after 12 weeks. The magnitude of orthodontic forces ranged between 1 and 3 N. After orthodontic treatment, the implants were removed with a trephine drill. Histological workup by the cutting and grinding technique was performed for nearly the last third of palatal implants. Outcome variables were clinical implant survival and histological BIC rates. The implants in both groups were initially stable at the time of insertion. However, 3/36 in group 1 and 1/40 in group 2 were lost. The remaining implants were clinically stable and no mobility was recognized. The median BIC rates were 76% (SD, 25) in group 1 (n=10) and 84% (SD, 13) in group 2 (n=12) (P=0.262; Mann-Whitney U-test, not significant). The data support the concept of immediate indirect loading on palatal implants with forces of up to 3 N. On histological evaluation, immediate loading yielded similar BIC rates as conventional loading.