title: Reinforcement of experimental composite materials based on amorphous calcium phosphate with inert fillers.
abstract: OBJECTIVE
  The aim of this study was to examine the influence of the addition of glass fillers with different sizes and degrees of silanization percentages to remineralizing composite materials based on amorphous calcium phosphate (ACP).
  
  
  METHODS
  Four different materials were tested in this study. Three ACP based materials: 0-ACP (40 wt% ACP, 60 wt% resin), Ba-ACP (40 wt% ACP, 50 wt% resin, 10 wt% barium-glass) and Sr-ACP (40 wt% ACP, 50 wt% resin, 10 wt% strontium-glass) were compared to the control material, resin modified glass ionomer (Fuji II LC capsule, GC, Japan). The fillers and composites were characterized using scanning electron microscopy. Flexural strength and modulus were determined using a three-point bending test. Calcium and phosphate ion release from ACP based composites was measured using inductively coupled plasma atomic emission spectroscopy.
  
  
  RESULTS
  The addition of barium-glass fillers (35.4 (29.1-42.1) MPa) (median (25-75%)) had improved the flexural strength in comparison to the 0-ACP (24.8 (20.8-36.9) MPa) and glass ionomer control (33.1 (29.7-36.2) MPa). The admixture of strontium-glass (20.3 (19.5-22.2) MPa) did not have any effect on flexural strength, but significantly improved its flexural modulus (6.4 (4.8-6.9) GPa) in comparison to 0-ACP (3.9 (3.4-4.1) GPa) and Ba-ACP (4.6 (4.2-6.9) GPa). Ion release kinetics was not affected by the addition of inert fillers to the ACP composites.
  
  
  CONCLUSIONS
  Incorporation of barium-glass fillers to the composition of ACP composites contributed to the improvement of flexural strength and modulus, with no adverse influence on ion release profiles.
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Croatia. Electronic address: marovic@sfzg.hr.
authors.forename: Danijela
authors.initials: D
authors.lastname: Marovic
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Croatia.
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Tarle
authors.affiliation: Department of Operative Dentistry and Periodontology, University Hospital Regensburg, University of Regensburg, Germany.
authors.forename: Karl-Anton
authors.initials: KA
authors.lastname: Hiller
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Regensburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Müller
authors.affiliation: Department of Prosthodontics, University Hospital Regensburg, University of Regensburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Rosentritt
authors.affiliation: Dr. Anthony Volpe Research Center, ADA Foundation, Gaithersburg, MD, USA.
authors.forename: Drago
authors.initials: D
authors.lastname: Skrtic
authors.affiliation: Department of Operative Dentistry and Periodontology, University Hospital Regensburg, University of Regensburg, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry*; D003188:Composite Resins; D008855:Microscopy, Electron, Scanning
chemical_list: D002130:Calcium Phosphates; D003188:Composite Resins; C020243:calcium phosphate
keywords: Amorphous calcium phosphate; Fillers; Flexural modulus; Flexural strength; Ion release