A Critical Review on the Conversion Degree of Resin Monomers by Direct Analyses

Abstract

Objectives: The aim of this study was to carry out a review on the methods of direct detection of composite resins´ degree of conversion.Data/sources: The authors searched the Cochrane Library, Embase, PubMed, and the Web of Science (ISI) for papers dated from January 1991 to November 2011. The search was complemented by manual searches of the reference lists from each identified relevant paper. The main search terms were: “degree of conversion”, “monomers”, “polymers”, “composite”, “pre-gel”, “post-gel”, “residual monomers” and “double bond”.Study selection: The inclusion criteria were studies that evaluated consolidated methods in the literature to directly evaluate the degree of conversion. Excluded studies were those considered to be unrelated to the question addressed, such as mechanical and physical properties and also monomers from adhesive systems and compomers. The selected papers were assigned to a score (A, B or C), according to the predetermined criteria. A total of 45 papers were selected and 15 papers were included in the critical appraisal. Two articles were labeled as grade A, nine articles were labeled as grade B, and four articles were labeled as grade C. Conclusions: According to the definitions of evidence levels, the current article study showed a strong evidence of review. Clinical significance: The monomer´s degree of conversion predicts the quality of polymers.

The Effect of Incorporating Different Concentrations of Octenidine Dihydrochloride on the Degree of Conversion of an Experimental Flowable Resin Composite

“…The main methods commonly used to measure the DC of resin composites are the FTIR spectroscopy, the Raman and the FT-Raman spectroscopy [17]. FTIR spectroscopy was used to determine the DC of the resin composites in this study.…”

“…FTIR spectroscopy was used to determine the DC of the resin composites in this study. The use of an interferometer to separate the spectral components and a mathematical technique to speed up the measurement is referred to as FTIR [17].…”

“…It is important to note that (a) radiation absorption is much more efficient (109 times) than scattering (b) IR absorption measurements are more appropriate for polar systems who have substantial transfers between atoms or molecules, such as the chemical bonds formed by polymerization of resin monomers. Based on these considerations the FTIR was the method of choice in this study as it is the simplest and most reliable technique [17]. FTIR detects the amount of unreacted C = C in the resin matrix and C = C stretching vibrations directly before and after curing of resin composite to determine changes in mechanical performance [18].…”

Photopolymerization Kinetics of Methacrylate Dental of Resin by Transmission FTIR Method and Reliable Methodology

“…[1][2][3] although another peak maximum e.g. 1730 or 4623 cm -1 are also used [4]. The method is correct if this reference band shows the same intensity over the entire DC range.…”

Evaluation of photopolymerization efficacy and temperature rise of a composite resin using a blue diode laser (445 nm)

“…A complete conversion of carbon double bonds in a composite is unattainable due to the three‐dimensional network development that functions as an obstacle for unreacted molecular chains to approach and react. In vitro and laboratory experiments indicate that it is possible to obtain a DC of up to 80%; however, for under intra‐oral clinical conditions, the DC will be 70% or less, basically depending on the intensity of the light source, duration of irradiation, distance of the composite surface from the tip of the device, and depth of measurement (4).…”