가토에서 다공성 Nickel-Titanium Alloy Implant의 골 및 조직 반응

Abstract

Introduction Porous Nickel-Titanium(Ni-Ti) alloy implants were previously introduced and a number of studies were performed. Porous nickel-titanium alloys have excellent properties such as excellent biocompatibility, high osseointegration rate, superelastic and shape memory properties, which are valuable in the dental field. It may be considered to use a porous Ni-Ti coating to combine the advantages of Ni-Ti with titanium implants. The aim of this study was to investigate the tissue response of porous Ni-Ti alloy in vivo. It is important to verify biological stability by evaluating new bone formation and surrounding tissue reactions of porous Ni-Ti alloys to be used as coatings. In the experiment, a disc-shaped porous Ni-Ti alloy was applied to the skull of rabbit, and new bone formation and inflammation reaction were observed.

Materials and Methods Three calvaria bone defects were formed on the adult male New Zealand Rabbits weighting 3∼3.5kg. The calvaria defect was formed in 8 mm diameter. The specimens were fabricated in the form of a porous Ni-Ti alloy disc with a diameter of 8 mm and a thickness of 1 mm. There were one control group and two experimental groups. In the control group, only the collagen membrane was applied to the defect. In the experimental group I, the disc was applied to the defect with bone graft and resorbable membrane. In the experimental group II, the disc was placed in the defect covered by resorbable membrane. After 4 and 8 weeks of healing, the experimental animals were euthanized for specimen preparation. Histomorphometric analysis was performed to quantify new bone formation and connective tissue. The data were analyzed by Kruskal - Wallis test and Mann-Whitney test.

Results At 4 and 8 weeks, new bone formation was seen in all groups. However, it was not statistically significant. In the experimental group, the amount of new bone was smaller than that in the control group, and more new bone formation was seen in the bone grafted group. The new bone formation was not enough compared to the study of titanium implants. There was slight inflammation in the experimental groups compared to the control group.

Conclusion In this study, new bone formation and tissue reactions were seen around the porous Ni-Ti alloy. There was slight inflammation and insufficient new bone formation in the experimental groups. This means that there was an effect of porous Ni-Ti alloy on adjacent tissue. More researches on porous Ni-Ti alloy surfaces is likely to be needed. In future studies, porous Ni-Ti alloys may be proposed as an effective coating material when better bone formation and tissue response will be seen.