Bioactive composites containing TEGDMA-functionalized calcium phosphate particles: Degree of conversion, fracture strength and ion release evaluation.
To evaluate the strength and ion release of experimental composites containing TEGDMA-functionalized calcium phosphate particles.



Seven composites containing equal parts (in mols) of BisGMA and TEGDMA and 60vol% of fillers were manipulated. Filler phase was constituted by silanized barium glass and 0% (control), 10% or 20% (volume) of dicalcium phosphate dihydrate (DPCD) particles, either non-functionalized or functionalized with two different TEDGMA contents. DCPD particles were synthesized and characterized by X-ray diffraction (XRD), elemental analysis, surface area and dynamic light scattering. Composites were tested for degree of conversion (DC) by near-FTIR. Biaxial flexural strength (BFS) was determined after 24h and 28days in water. Calcium and phosphate release after 7days was assessed using inductively coupled plasma optical emission spectrometry (ICP-OES). Data were analyzed by ANOVA/Tukey test (alpha:5%).



XRD confirmed the crystalline structure corresponding to DCPD. Elemental analysis revealed particles with zero, 14% or 22% TEGDMA, with similar D50(around 19μm) and surface areas from 3.5 to 11.4m2/g. The presence of DCPD did not reduce DC. After 24h, functionalization (both 14% and 22% TEGDMA) improved composite strength in comparison to non-functionalized DCPD, both at 10% and 20% levels. After 28days, BFS of materials containing 10% functionalized DCPD were statistically similar to the control containing only barium glass. Among composites containing 10% DCPD, particle functionalization with 14% TEGDMA did not jeopardize ion release.



At 10vol%, the use of TEGDMA-functionalized CaP particles improved composite strength in relation to non-functionalized particles, while maintaining similar ion release levels.
Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil.
Yvette
Y
Alania
Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil.
Marina D S
MD
Chiari
Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil.
Marcela C
MC
Rodrigues
Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil.
Victor E
VE
Arana-Chavez
Materials Science and Technology Center, Energy and Nuclear Research Institute, Av. Prof. Lineu Prestes 2242, São Paulo, SP 05508-000, Brazil.
Ana Helena A
AH
Bressiani
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP 05508-000, Brazil.
Flavio M
FM
Vichi
Department of Biomaterials and Oral Biology, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes 2227, São Paulo, SP 05508-000, Brazil. Electronic address: rrbraga@usp.br.
Roberto R
RR
Braga
D017438:Bisphenol A-Glycidyl Methacrylate; D002130:Calcium Phosphates; D003188:Composite Resins; D003764:Dental Materials; D008422:Materials Testing; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids
D002130:Calcium Phosphates; D003188:Composite Resins; D003764:Dental Materials; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate
Calcium phosphate; Ion release; Mechanical properties; Resin composite