Experimental study on porous apatite as artificial bone. Experiment on implantation in the mandible

Abstract

It was reported by the author that the porous apatite could be an effective artificial bone. This time, for the purpose of investigating the clinical use of the porous apatite in the oral and maxillof acial area, experiment on implanting the material in the mandible was made.Two months after extracting the P3, P4 and M1 from the adult dog mandible, bone defects each 20 mm mesio-distally long and about 15 mm deep were produced with the underlying mandibular margin left intact. Into each defect, the porous apatite (porosity rate: about 700) was implanted from the inside of the oral cavity.Dogs were sacrificed after one week to 24 months and the examination of the tissue specimens obtained indicated : After one week, bone formation begins on the surface of the apatite adjacent to the newly formed bone around the original bone. After three months, a large amount of bone forms inside and on the porous apatite. After six months, the compact bone forms both inside the outer marginal pores and on the outermost surface of the apatite; in almost all of the pores inside and lower border of the porous apatite a lamellar bone is formed on the wall of each pore and a large yellow bone marrow is formed inside the pore. These conditions existed till 24 months after the operation.The above results imply that the porous apatite is full of promise as a filling material for use in bone defects in the oral and maxillofacial area.