AMORPHOUS CALCIUM PHOSPHATE COMPOSITES AND THEIR EFFECT ON COMPOSITE/ADHESIVE/DENTIN BONDING
Joseph M. Antonucci, Justin N. O'Donnell, Gary E. Schumacher, Drago Skrtic
This study evaluates the bond strength and related properties of the photo-polymerizable, remineralizing amorphous calcium phosphate (ACP) polymeric composite/adhesive systems to dentin after various periods of aqueous aging at 37 oC. An experimental ACP base and lining composite was made from a photo-activated resin comprising 2,2-bis[p-(2 -hydroxy-3 -methacryloxypropoxy)phenyl]propane (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA) and zirconyl dimethacrylate (ZrDMA); designated BTHZ. An experimental orthodontic composite was formulated from a photo-activated resin comprising ethoxylated bisphenol A dimethacrylate (EBPADMA), TEGDMA, HEMA and methacryloxyethyl phthalate (MEP); designated ETHM. In both composite series three fillers were compared: 1) a zirconium modified ACP freshly precipitated (as-made Zr-ACP), 2) milled Zr-ACP and 3) an ion-leachable fluoride glass. In addition to the shear bond strength (SBS), work to fracture, and failure modes of the orthodontic composites were determined. The SBS of the base and lining ACP composites appeared unaffected by filler type or immersion time. In the orthodontic ACP composite series, milled ACP composites showed initial mechanical advantages over as made-ACP composites, and produced higher incidence of a failure mode consistent with stronger adhesion. After six months of aqueous exposure, 80 % of specimens failed at the dentin/primer interface, with a 42 % overall reduction in bond strength. BTHZ and ETHM based ACP composites are potentially effective anti-demineralizing/remineralizing agents with possible clinical utility as protective bases/liners and orthodontic cements, respectively. The analysis of the bond strength and failure modalities suggests that milled ACP composites may offer greater potential in clinical applications.
, O'Donnell, J.
, Schumacher, G.
and Skrtic, D.
AMORPHOUS CALCIUM PHOSPHATE COMPOSITES AND THEIR EFFECT ON COMPOSITE/ADHESIVE/DENTIN BONDING, Journal of Adhesion Science and Technology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=853597
(Accessed June 5, 2023)