Technetium 99m-MDP scintigraphy of patients undergoing implant prosthetic procedures: a follow-up study

The clinical evaluation of peri-implant tissue is mainly based on x-rays. In recent years, radioisotope scintigraphy using Tc-99m-MDP (technetium-99m-methylene diphosphonate) proved to be a useful and reliable clinical method for measuring increased metabolic activity at specific sites of the skeletal tissue. Twenty-six (26) patients (26 to 75 years) who were diagnosed for implant prosthetic treatment modality were randomly chosen to participate in this study. Each patient was injected with 20 mCi of Tc-99m-MDP was scanned 2 hours later by gamma-camera for isotope uptake levels in the jaws. Each patient was scanned 1 to 4 times, starting 2 weeks after implant surgery and up to the 40th week postsurgery. Blade and screw type implants using the non-submerged, one-stage technique were placed. Therefore, the prosthetic reconstruction was initiated 2 weeks after implant surgery. In order to compare the different scans we formulated a relative "bone scan index" (BSI). The results of 62 scans were plotted as BSI against time after implant surgery. A mathematical regression analysis of the BSI was also performed. At the initial stage of 2 to 3 weeks after surgery the BSI is high and then gradually declines. While BSI of the implants in the mandible reaches baseline levels after 12 weeks, the BSI in the maxilla reaches baseline only after 20 weeks. On the other hand, there was no difference in BSI with regard to blade or screw type implant. Here we were able to demonstrate that the process is independent of implant modality and depends on the specific metabolic properties of the jaw.(ABSTRACT TRUNCATED AT 250 WORDS)