title: Effect of pH on Porphyromonas gingivalis endotoxin affinity for resins.
abstract: This study evaluated the effect of pH on Porphyromonas gingivalis lipopolysaccharide (LPS) affinity for polymethyl methacrylate, polyethyl methacrylate, and polyethyl and polyisobutyl methacrylate resins. Specimens were exposed to 1,010 endotoxin units LPS in potassium phosphate buffer at pH 6, pH 7, or pH 8. Control specimens were incubated in LPS-free water. Sequence I evaluated LPS uptake and release from resin when exposure and elution pH were identical, whereas Sequence II evaluated LPS release from resin when elution pH differed from exposure pH. A slightly acidic pH decreased LPS affinity for all resins compared to pH 7. A slightly alkaline pH increased LPS affinity for the polyethyl methacrylate resin but decreased LPS affinity for the others compared to pH 7. The pH may affect resin-LPS affinity by altering LPS molecular charge.
authors.affiliation: Medical College of Georgia School of Dentistry, Augusta, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Knoernschild
authors.forename: G R
authors.initials: GR
authors.lastname: Tompkins
authors.forename: C A
authors.initials: CA
authors.lastname: Lefebvre
authors.forename: L L
authors.initials: LL
authors.lastname: Griffiths
authors.forename: G S
authors.initials: GS
authors.lastname: Schuster
mesh_terms: D000704:Analysis of Variance; D001422:Bacterial Adhesion; D006863:Hydrogen-Ion Concentration; D008070:Lipopolysaccharides / Q000737:chemistry*; D008768:Methylmethacrylates / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry*; D016966:Porphyromonas gingivalis / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D008768:Methylmethacrylates; D011109:Polymethacrylic Acids; C069716:Jet, dental resin; C091347:vinyl ethyl methacrylate