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Real‐time curing characteristics of experimental resin composites containing amorphous calcium phosphate
Author(s) -
Par Matej,
Tarle Zrinka,
Hickel Reinhard,
Ilie Nicoleta
Publication year - 2018
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/eos.12566
Subject(s) - composite material , materials science , curing (chemistry) , polymerization , fourier transform infrared spectroscopy , methacrylate , amorphous calcium phosphate , composite number , amorphous solid , calcium , chemistry , polymer , chemical engineering , organic chemistry , engineering , metallurgy
The real‐time polymerization of light‐curable experimental resin composites filled with amorphous calcium phosphate ( ACP ) was monitored. Experimental composites were based on a 2,2‐bis[4‐(2‐ethoxy‐3‐methacryloyloxy propoxy)phenyl]propane (Bis‐ EMA )/triethyleneglycol dimethacrylate ( TEGDMA )/2‐hydroxyethyl methacrylate ( HEMA ) resin photoactivated by a camphorquinone/tertiary amine system. Four ACP composites were prepared, containing 40 wt% ACP and 0/10 wt% reinforcing fillers (barium glass and silica). Additionally, two control composites were prepared which contained only reinforcing fillers (40–50 wt%). The degree of conversion ( DC ) was monitored in real time using a Fourier‐transform infrared ( FTIR ) spectrometer with an attenuated total reflectance accessory. During the light curing (1,219 mW cm −2 ) for either 20 or 40 s, infrared spectra were collected from the bottom of 2‐mm‐thick composite specimens at the rate of two spectra per second over 5 min. When cured for 40 s, the ACP composites attained a high DC (89.1%–92.4%), while the DC of control composites was significantly lower (53.5%–68.4%). All materials showed a lower DC for the shorter curing time (20 s) and various extents of 5‐min postcure polymerization: 12.9%–21.5% for the ACP composites and 2.7%–5.2% for the control composites. The control composites reached the maximum reaction rate much earlier (4.1–4.3 s) and at lower DC (9.9%–10.4%) than did the ACP composites (17.4–22.0 s and 43.5%–49.3%, respectively).