Porphyromonas gingivalis endotoxin affinity for dental ceramics

This study evaluated the effects of chemical composition, surface treatment, and initial exposure dose on Porphyromonas gingivalis lipopolysaccharide adherence to and elution from dental ceramics. Lipopolysaccharide, commonly known as endotoxin, can initiate a variety of biologic responses. Opaque, body, and Dicor ceramic disks were individually exposed to 250, 1000, or 2500 EU/ml 3H-lipopolysaccharide and incubated for 24 hours at 37 degrees C. Disks were then transferred to fresh lipopolysaccharide-free water and incubated for up to 96 hours to evaluate elution. Mean initial lipopolysaccharide adherence ranged from 0.397 +/- 0.048 EU/mm2 to 5.056 +/- 0.117 EU/mm2. Greater initial exposure levels resulted in greater adherence, and at higher lipopolysaccharide exposure levels, lipopolysaccharide adherence differences were based on ceramic type. Mean lipopolysaccharide elution levels ranged from 0.063 +/- 0.02 EU/mm2 to 0.00 EU/mm2 at 96 hours for all groups. Greater initial adherence resulted in greater elution. Ceramic type did not affect elution. Surface finish affected elution at the 2500 EU exposure level. The affinity of lipopolysaccharide for dental ceramics could contribute to a periodontal inflammatory process.