ABSTRACT
BACKGROUND: The direct ratio is formed between the size of osseous defect around implant and the required time of complete repair. It is viewed that bone implantation is suggested if osseous defect is larger than 1 mm, which benefits the bone regeneration and early fixation of implant.OBJECTIVE: To compare the effects between coralline granules and hydroxyapatite (HA) during union after immediate implantation.DESIGN: Group observation and controlled experiment was designed.SETTING: Department of Stomatology Renmin Hospital of Wuhan University.MATERIALS: HA coated implant, HA granule, coralline granule and 3adult mongrel dogs.METHODS: The experiment was performed in Department of Stomatology, Renmin Hospital of Wuhan University from August 2002 to April 2003.Under anesthesia, 6 foramens were drilled on femurs of 3 dogs (3 foramens on each side) to result in osseous defect. Coralline granules were embedded in the osseous defect around the implant in all of proximal ends (coralline granule group, CG group), HA granules were embedded in the osseous defect around the implant in all of distal ends (HA group) and nothing was embedded in the defect around the implant in the center (the control). One dog was sacrificed under anesthesia on the 2nd, 3rd and 4th months after operation successively and the samples were collected from the implanted section in each group for X-ray examination and scanning electronic microscopic observation.MAIN OUTCOME MEASURES: X-ray examination on implanted sections and scanning electronic microscopic observation on samples in each the 4th month, it was observed that implants and osseous tissue were closely integrated in CG group and HA group and there was still partial osseous on samples in each group: on the 4th month, it was discovered that the regenerated osseous tissue was matured completely in CG group and few coralline granule residue was left. In HA group, the regenerated osseous tissue was matured completely, but there was still a large amount of HA granules left and the granules had not been absorbed obviously. In the control group, the space appeared partially in the implanted cervical region.CONCLUSION: The implantation of artificial bone is suggested if the osseous defect around immediate implant is larger than 1 mm. As the implanting materials, coralline granules and HA granules act on the most advantageous guide activity. Coralline granules can be degraded and substituted with osseous tissue,but HA granules cannot be absorbed, which affects osseous reconstruction.