The effect of Staphylococcus epidermidis on the pH and dissolution of substitute bone graft materials

Abstract

The objective of this study was to determine the effect of S. epidermidis 11047 on the pH and dissolution of 5 different bone substitute materials. Part 1 – Measured the pH, calcium and phosphate of the culture medium in the presence and absence of the 5 bone substitute materials before and after autoclaving. Part 2 – Measured the pH of the culture medium in the presence and absence of the 5 bone substitute materials before autoclaving and measurement of pH, calcium and phosphate 24 hrs later following incubation in the presence or absence of S. epidermidis. In part 1 it was concluded that autoclaving does not have a clinically significant effect on pH, calcium or phosphate levels of a culture medium in the presence or absence of the 5 bone substitute materials for the purposes of this study. There was a statistically significant reduction in pH, with a maximum decrease of 0.09. In part 2 it was concluded that there was a statistically and potentially clinically significant reduction in pH caused by the presence of S. epidermidis in all test samples and Cerasorb M (H4) is degraded in the presence of S. epidermidis