Micro-CT evaluation of bone grow concept of an implant with microstructured backtaper crestally and sub-crestally placed. Preliminary study in New Zealand rabbits tibia at one month

The primary purpose of this study was to determine the accuracy of micro-computed tomography (micro-CT) as a novel tool for the 3D analysis of bone density around dental implants in tibia rabbits. Six male New Zealand rabbits were used in our evaluation. One Copa SKY (R) (Bredent Medical GmbH & Co. K.G.) with a 3.5 mm diameter by 8.0 mm in length was placed within 12 tibia rabbits divided into two experimental groups: Group A (crestal placement) and Group B (sub-crestal placement). The animals were sacrificed at four weeks. Micro-CT evaluations showed a high amount of bone around all implants in the tibia rabbit bone. There was an increased formation of bone around the Copa SKY implants, mainly in the implants that were placed crestally. The most frequent density found in most implants was a medullary bone formation surrounding the implant; the density three (D3) was the most common type in all implants. The 3D model analysis revealed a mean bone volume (B.V.) of 31.24 +/- 1.24% in crestal implants compared with the 43.12 +/- 0.43% in sub-crestal implants. The mean actual contact implant to bone (B.I.C.) in the sub-crestal group was 51.76 +/- 0.86%, compared to the 42.63 +/- 0.75% in the crestal group. Compared to crestal implants, the Copa Sky implant placed sub-crestally allows for the formation of bone on top of the neck, thereby stimulating bone growth in tibia rabbits.