Purpose: The aim of this prospective pilot study was to investigate differences in changes in implant stability and crestal bone height between loaded and unloaded dental implants at 4 months after placement. Materials and Methods: In the test group, 20 implants were placed in the anterior region of the mandible in 10 patients. They were connected with a Dolder bar within 10 days and placed into function immediately. In the control group, 21 implants were placed in the anterior region of the mandible in a 2-stage procedure in 12 patients. The implants used were TiUnite, with a diameter of 3.75 mm and a minimum length of 10 mm. Resonance frequency analysis was used to measure differences in implant stability, with the implant stability quotient (ISQ) as the unit of measure. An instrument was developed to measure the bone level directly. On a customized abutment, a probe with a stopper measured the distance between the shoulder of the instrument and the bone. Measurements were made on all 4 sides of each implant. Intra- and interexaminer variability showed an agreement that was greater than 99% (kappa > 0.99) for both sets of measurements. Results: In the early loading group, the mean change in ISQ was -0.08 ± 0.77 and the mean bone loss from buccal, mesial, distal, and lingual sites was 0.69 ± 0.15 mm. In the unloaded group, the mean change in ISQ was 1.33 ± 1.65 and the mean bone loss from buccal, mesial, distal, and lingual sites was 0.53 ± 0.18 mm. There was no statistically significant difference across the 2 treatment groups. The changes in bone height at buccal and lingual sites were not statistically different from the changes at mesial and distal sites. When gender was included as a factor, the changes in stability and bone loss were statistically smaller among female patients than among male patients. Conclusion: In this preliminary study, early loading did not show an influence on bony crest height and stability in TiUnite implants placed in the anterior mandible during the first 4 months of service.
Int J Prosthodont 2005;18:506–512