Single photon emission computerized tomography in the evaluation of the osteoblastic activities of a new bone regeneration technique: analysis of 12 mandibular sites in six experimental pigs.

OBJECTIVES To utilize single photon emission computerized tomography performed in sequence to determine the osseo-integrating capabilities and osteoblastic activities of a new bone regeneration technique called the membrane--sandwich technique (Ogunsalu sandwich bone regenerating technique) and to compare the quality and quantity of bone formed by this bone regeneration unit to bone regeneration obtained by using the same particulate bone grafting material covered with interceed (another type of bio-resorbable membrane). DESIGN AND METHOD Single photon emission computerized tomography bone imaging was performed in sequence on the mandible of a total of 6 pigs on both the right and left side (total of 12 sites) at two and a half hours following the injection of technetium 99m methylene diphosphate. Imaging was performed using a Siemen Orbitar II gamma camera. The projection data was acquired in a 128 x 128 matrix over 180 arc and SPECT reconstruction was performed using a filtered back projector method with a Shepp-Logan Hanning filter and a cut-off frequency of 0.4. The surgical defect on one side of the jaw was treated with the sandwich unit with Bio-oss particulate bone within it, while the other side contained the same quantity of Bio-oss as in the left side but just covered with interceed membrane. The osteoblastic uptake on the side with the classical sandwich was compared to the side with the particulate bone covered with interceed membrane for dynamic physiological activities. The average activity for both sides was calculated and compared. RESULT For all the 12 sites, osteoblastic activities were recorded and indicated that vascularized bone was formed at all the experimental sites. Autogenous bone graft was confirmed to be superior to xenograft using this sandwich technique. Furthermore, the osteoblastic activities on the sandwich side were seen to be more when compared with the control side (Interceed side). CONCLUSION The Ogunsalu sandwich bone regeneration technique has been successfully evaluated with SPECT which shows osteoblastic activity with formation of vascularized bone which integrates with the surrounding bone.