Pure Magnesium Ultrasonic Micro-arc Oxidation-Phytic Acid-fibroin Composite Coating Degradation Characteristics

Objective: Clinical application of bone fixing metal implant material is not biodegradable currently, patient needed reoperation implant removal after bone tissue is healed, which brings more pain to the patient. In order to achieve pure magnesium implant in vivo degradation of regulation, we gave the surface activity of microarc oxidation coatings on pure magnesium ultrasonic sealing of phytic acid SF deposition, and find its biodegradable can benefit bone fixation and promote healing.Methods: Put the pure magnesium materials into ultrasonic vibration, cleaning acetone solution for 10 minutes, take it out and put it into ethanol, and ultrasonic vibration cleaning for 10 minutes, finally placed into distilled water, then ultrasonic vibration cleaning for 10 minutes and then remove to hang dry. Micro-arc oxidation solution is silicate solution. Ultrasonic ultrasonic's power is 50 W, frequency is 60 k Hz, pulse frequency is 500 Hz, micro-arc oxidization voltage is 300 V, duty is 2.5%, time to 10 minutes. Make the prepared pure magnesium plant hanging to dry indoor, and set aside. Phytic acid 7.5 g/l and add traces of sodium fluoride with boric acid, the test piece hanging in phytic acid in the liquid, 40 °C water bath heating 10 minutes, remove the Interior dry and set aside. Hang the phytate treated samples soaked in 3% of silk fibroin solution 1.5 h, remove indoor hanging to dry and set aside. Make 3 pure magnesium implant for ethylene oxide sterilization in the reserve. Pure ultrasonic microarc oxidation of magnesium implants as a control group-phytic acid in Group A, pure magnesium ultrasonic micro-arc oxidation coating implant for experiments in Group B, pure ultrasonic micro-arc oxidation of magnesium-phytic acid-fibroin composite coatings on implants for the experimental Group C. Make the three implants in rabbit's mandibular,observe the treatment the degradation process of pure magnesium implants 2 weeks and 6 weeks after, through the magnesium ions in blood and urine biochemical tests, Cone beam CT(CBCT), scanning electron microscopy(SEM) and torque test to observe different implant characteristics and bone healing.Results: Serum and urinary magnesium ion showed that magnesium concentration in the Group A is higher than group B and group C. The magnesium ion concentration of Group C is the most stable, and showed that three groups of implant material can make degradation in the body, magnesium ion solubility mainly excreted in urine, drain of blood, supplemented by Group C material can slow degradation rate. At the same time, Cone beam CT(CBCT) to observe the growth of bone tissue results in Group C > B > A, degradation rate for group A > B > C. Scanning electron microscopy showed that degradation rates in Group B > C. Torsion test for bone growth in Group C > B > A, the results of three groups are statistically.Conclusion: Three groups of planting material, we can say that implants of pure ultrasonic micro-arc oxidation of magnesium-phytic acid-fibroin composite can slow degradation rate, and can benefit bone fixation and promote bone healing.