Calcium sulfate can be mixed up with antibiotics, and in my experiments, what we do is we look for the release of antibiotics over time from the calcium sulfate. And what we notice, is as the calcium sulfate dissolves we have a longer plateau of release of antibiotic from the calcium sulfate than we might from a non-absorbable material such as polymethylmethacrylate. So we see potential efficacy over much longer time periods in terms of being able to kill the biofilm. But also, when we look at elution, the concentration of antibiotics coming out of the calcium sulfate, we see that the concentration remains higher for longer periods than it does out of the PMMA. An advantage of using antibiotic beads in addition to antibiotic loaded spacers is that they increase the zone of coverage.