In vitro and in vivo biocompatibility tests of XeraCem™

Of the many requirements of a final luting agent, biocompatibility ranks as one of the most important properties. The ANSI/ADA Spec. 41 and ISO 10993:2002 recommend in vitro and in vivo tests to determine whether biocompatibility requirements are met Objectives: To test biocompatibility of an experimental self-sealing acid-base reaction cement (XeraCem™) in vitro and in vivo. Materials and Methods: In vitro: Cytotoxicity (filter diffusion test), irritation in hamsters, contact sensitivity in guinea pigs and Ames tests were carried out according to ISO 10993:2002. In vivo according to ANSI/ADA: In subhuman primates under general anesthesia, Class V inlay preparations were made and composite resin inlays fabricated and cemented with XeraCem™. Pulpal reactions were assessed histologically over two time periods, 30 and 85 days. Each time period generated 7 cemented inlays. After perfusion euthanasia with 10% neutral buffered formalin, the teeth were sectioned, decalcified and processed for routine histological analysis Sections of 6 microns were cut and stained using H&E. RDT, superficial and deep inflammation and other parameters were scored. Results: In vitro results indicate XeraCem™ to be none to mildly cytotoxic, 3 of 6 samples scored 0 and 3 scored 1. All other parameters were negative. All in vivo tests showed no significant deviation in reaction of the experimental material to the control groups. In vivo data from the primates after 30 days. All RDT values were below 1mm. Superficial and deep inflammation were absent in all but one specimen (0.50). After 85 days the mean RDT was 0.85mm and no inflammation was observed.

Conclusion: XeraCem™ demonstrated favorable biocompatibility properties when tested in vitro and in vivo. Based on the results above the cement is suitable for clinical testing in humans. (This study was supported in part by Doxa Dental AB)