Exposure of transformed and non-transformed phagocytic cells to novel glass ionomers in culture.

The use of glass ionomers as a novel bone cement is currently being investigated. Although acceptable for use as a dental restorative material, there is little information regarding how ionomers interact with inflammatory macrophage cell types. The specific objective of this experiment was to investigate the possible interrelationship between RAW and human monocyte/macrophage cells at the biochemical and morphological level after being in contact with three different dental cement ionomers (Fuji Duet, Fuji IX, and GC-Fuji-Ortho, GC America Inc., Chicago IL) for 72 hours. Transformed RAW macrophages were obtained from the American Type Culture collection (ATCC), and the non-transformed human macrophages were obtained from the peripheral blood of 25 male and female volunteers. The cells were plated at a density of 4 x 10(6) cells/ml in twenty-four well plates. Each plate was divided into four groups of six cells/group. Twenty-four hours after plating, the cells in groups I-III were incubated with Fuji Duet, Fuji IX, GC Fuji Ortho, respectively, and cells in Group IV were incubated with media alone to serve as controls. Immediately after addition of the ionomers, the cellular morphology was monitored for both transformed and non-transformed cells. Cell number data revealed that normal non-transformed cells were similar in number to control cells in media alone. This result suggests that the polymer treatment did significantly alter cellular viability. On the other hand, RAW cell number was markedly reduced in cells treated with ionomers in comparison to cell growing in media alone. The data suggests that the prescence of the ionomer may reduce the proliferation rate of RAW cells. Biochemical analysis of cellular supernatants to determine cellular alterations at 72 hours revealed increased levels of lactate dehydrogenase activity and levels of malionaldehyde bis diethyl acetal in all ionomer-treated groups of RAW cells compared with media alone. Non-transformed macrophages treated with the same ionomers did not differ significantly from the control cells in media alone. However, when comparing the levels of lactate dehydrogenase activity between the transformed and non-transformed cells it was apparent that the normal cells exhibited statistically higher activity than the RAW transformed cells. The results of this study suggest that although the three ionomers tested were found to be highly biocompatible with fully differentiated non-transformed macrophages, the behavior of transformed and non-transformed phagocytic cells towards these ionomers may not be similar under similar conditions.