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Degree of Conversion, Depth of Cure, and Color Stability of Experimental Dental Composite Formulated with Camphorquinone and Phenanthrenequinone Photoinitiators
Author(s) -
Albuquerque Pedro Paulo A. C.,
Bertolo Marcusv. L.,
Cavalcante Larissa M. A.,
Pfeifer Carmem,
Schneider Luis F. S.
Publication year - 2015
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12131
Subject(s) - photoinitiator , triethylene glycol , dental composite , materials science , nuclear chemistry , composite number , photopolymer , fourier transform infrared spectroscopy , amine gas treating , chemistry , analytical chemistry (journal) , polymer chemistry , composite material , polymer , chromatography , chemical engineering , organic chemistry , polymerization , monomer , engineering
Purpose This study evaluated the applicability of 9,10‐phenanthrenequinone ( PQ ) in experimental dental composites. Materials Camphorquinone ( CQ ), PQ , ethyl 4‐ N , N ‐dimethylaminobenzoate ( EDMAB ) and diphenyliodonium salt ( DPI ) were employed. A mixture of 2,2‐bis(4‐[2‐hydroxy‐3‐methacryloxypropoxy]phenyl)‐propane/triethylene glycol dimethacrylate (60:40%) and silanated glass filler at 60% were used. A two‐peak‐based light‐emitting diode ( LED ) was used. Methods The photoinitiator absorption and the light emission spectra were determined by a Ultraviolet–visible spectroscopy and a spectroradiometer, respectively. Relative photon absorption ( RPabs ) was calculated. Fourier‐transformed infrared spectroscopy analysis was used to determine the degree of conversion ( DC ). The optical properties were determined with a spectrophotometer. Depth of cure was assessed from adapted International Organization for Standardization (ISO) 4049. Results were analyzed with descriptive analysis, analysis of variance, and T ukey's test (α = 5%). Results PQ showed higher RPabs than CQ . Regarding the DC , CQ + EDMAB (control), CQ + EDMAB + DPI , PQ + DPI , and PQ + EDMAB + DPI produced statistically similar results. Groups formulated with CQ presented higher depth of cure. Only the group formulated with CQ + EDMAB presented satisfactory color stability (Δ E < 3.3). Conclusion PQ presented higher RPabs than CQ and it was able to produce DC similar to CQ + EDMAB , when used with DPI . However, groups formulated with PQ produced lower depth of cure, greater yellowing, and less color stability than the traditional combination CQ and amine. Clinical Significance Although research with novel photoinitiator systems should be encouraged, the traditional camphorquinone and amine pair remains as a reliable combination for the formulation of dental composites.