SEM-EPMA OBSERVATION OF 3 TYPES OF APATITE-CONTAINING GLASS-CERAMICS IMPLANTED IN BONE - THE VARIANCE OF A CA-P-RICH LAYER

The progressive changes of a Ca‐P‐rich layer between bone and three types of apatite‐containing glass‐ceramics of the same chemical composition: MgO 4.6, CaO 44.9, SiO2 34.2, P2O5 16.3, CaF2 0.5 (in weight ratio) were examined. Plates (15 mm × 10 mm × 2 mm, mirror surface) containing apatite (35 wt%) (designated A‐GC), apatite (35 wt%) and wollastonite (40 wt%) (designated A · W‐GC), and apatite (20 wt%), wollastonite (55 wt%), and whitlockite (15 wt%) (designated A · W · CP‐GC) were prepared. They were implanted into the tibia of mature male rabbits for 5 days, 10 days, 20 days, 30 days, 60 days, 6 months, and 12 months. All three types of glass‐ceramics showed direct bonding to the bone 30 days after implantation. It was observed by SEM‐EPMA 30 days after implantation that Si and Mg content decreased, P content increased, and Ca content did not change across the reactive zone from the glass‐ceramics to bone. The level of P and Si in the A · W · CP‐GC changed five days after implantation. In A · W‐GC and A‐GC, a little change in P and Si levels was observed between 10 and 20 days after implantation. The width of reactive zone was narrowest with A‐GC, wider with A · W‐GC, and widest with A · W · CP‐GC. The dissolution of glass‐ceramics stopped 6 months after implantation. This phenomenon shows that the glass‐ceramics may be suitable for clinical use. Copyright © 1987 John Wiley & Sons, Inc.