가토 두개골결손부에 이식된 3차원적으로 프린팅된 폴리카프로락톤 스캐폴드의 골형성 효과

Abstract

I. Introduction Infection, cystic lesion, and alveolar defects due to trauma, a large amount of alveolar bone resorption after tooth loss or implant removal often make implant placement difficult because of the limited amount of alveolar bone. In order to solve this problem, guided bone regeneration(GBR) with particulate graft material and resorbable collagen membrane is the most widely used. However, particulate bone graft materials have clinically limitations in maintaining space and stability. The addition of collagen to particulate bone graft can achieve GBR by ensuring graft stability and space maintenance by molding the graft material to adapt to the defect. In addtion, studies to replace bone graft materials with biocompatible three dimensional scaffolds are being actively conducted. The purpose of this study was to compare the new bone formation effect of the PCL/β-TCP scaffold with the collagenated xenograft and synthetic bone scaffolds through radiographical and histological analysis.

II. Materials and Methods Four circular bone defects with a diameter of 8mm were formed on each of the calvaria of rabbits. Each defect in the calvarium was allocated to 1) control group, 2) TestⅠ, alloplastic bone scaffold made in block form using collagen fiber and synthetic bone composed of hydroxyapatite (HA) and beta-Tricalcium phosphate(β-TCP), 3) TestⅡ, Xenogeneic bone scaffold made in block form using deproteinized bovine bone mineral (DBBM) and collagen fiber, or 4) TestⅢ, 3D scaffold made by mixing poly ε-caprolactone (PCL) with β-tricalcium phosphate (β-TCP). A total of 8 rabbits were sacrificed at either 2 or 6 weeks post-surgery.

III. Results As a result of radiological and histological evaluation, it was observed that the largest amount of new bone was formed in the collagenated synthetic bone graft in 2 weeks and 6 weeks groups. Also, unlike the control group, where new bone formation was limited to the boundary of the bone defect, new bone formation was observed from the boundary to the center in collagenated synthetic bone graft. The PCL-TCP scaffold group showed the least amount of new bone formation compared to the control group. But, there was no statistically significant difference compared to the control group.

IV. Conclusion Based on these research results, the amount of new bone formation of the PCL/β-TCP 3D scaffold made of 200μm diameter filaments was lower than that of the SB scaffold (OsteonIII® collagen) and DBBM saffold (Bio-Oss® Collagen). However, as a result of the PCL/β-TCP scaffold after 6 weeks, new bone was formed at the edge without an inflammatory reaction, and in some cases, new bone growing above the scaffold was observed. Also, it was observed that the 3D scaffold did not be absorbed for 6 weeks and maintained the bone defect space. Based on this, it is expected that PCL/β-TCP 3D scaffold can be used as an alternative to the existing bone graft material. Future studies are needed to find the ideal material ratio, scaffold structure and conditions for new bone formation through the ratio of PCL and β-TCP, and changes in scaffold structure and surface treatment.