Effect of human bone morphogenetic protein 2 implant on tooth eruption in an experimental design

This study evaluated the influence of recombinant human bone morphogenetic protein 2 (rhBMP-2) on the development and eruption of the secondary dentit ion. Primary premolar tooth extraction sockets in 12 16-week-old felines we re implanted with either rhBMF-2 in collagen sponge or with buffer/absorbab le collagen sponge (ACS). Unoperated jaw quadrants sewed as controls. Exper imental conditions were randomized between jaw quadrants in all animals. Tw o animals receiving rhBMP-2/ACS and buffer/ACS in two quadrants per implant were sacrificed at 4 weeks postsurgery. Ten animals receiving rhBMP-2/ACS (two quadrants), buffer/ACS implants (one quadrant), and one quadrant sewin g as an unoperated control were evaluated at 12 weeks postsurgery. Clinical assessments included healing, eruption patterns, and crown development. Ra diographic assessments included tooth development, eruption patterns, and b one formation. Histological observations were also made from the 4-week ani mals. The secondary dentition remained unerupted at 4 weeks postsurgery, Hi stological analysis showed normal alveolar bone coronal to the erupting tee th in rhBMP-2/ACS-implanted quadrants. At 12 weeks postsurgery, all teeth w ere erupted without differences between quadrants. Clinically, the crowns o f all teeth were normal. Radiographs suggested that teeth in rhBMP-2/ACS- a nd buffer/ACS-implanted jaw quadrants exhibited similar tooth development a nd eruption patterns as the normal control. The evidence from this study su ggests that surgical implantation of rhBMP-2/ACS in the pathway of the deve loping and erupting secondary dentition does not interfere with the normal development and eruption patterns of the teeth.