J Korean Acad Prosthodont.  2008 Dec;46(6):639-643.

Degree of conversion of bis-acrylic based provisional crown and fixed partial denture materials

• Kim SH
• Watts DC

Abstract

STATEMENT OF PROBLEM: The degree of conversion may influence the ultimate mechanical and physical properties of provisional crown and fixed partial denture materials. The high levels of the unreacted residual monomer may cause deleterious effect on the properties. PURPOSE: The purpose of this study was to measure the degree of conversion of bis-acrylic based provisional crown and fixed partial denture materials by using an infrared spectroscopic method. MATERIAL AND METHODS: Chemically activated three bis-acrylic based provisional crown and fixed partial denture materials, LuxaTemp [DMG, Hamburg, Germany], fast set TemPhase [Kerr, Orange, CA, USA] and Protemp 3 Garant [3M-ESPE, St Paul, MN, USA], were investigated by Fourier transform infrared spectrometry (FTIR). The FTIR spectra of the materials tested were immediately obtained after mixing. The specimens were stored under dry conditions and at 23 degrees C for 24 hours, and then the spectra of the materials were also obtained. The degree of conversion (percent) was calculated from the spectrum of the absorbance between the aliphatic double bond at 1637 cm-1 and the aromatic double bond at 1608 cm-1 using the baseline method. The data were statistically analyzed using one-way ANOVA and the multiple comparison Scheffe test at the significance level of 0.05.
RESULTS
The mean value and standard deviation of the degree of conversion were 52.5 percent +/- 1.1 percent, 50.3 percent +/- 0.8 percent, and 42.3 percent +/- 4.9 percent for LuxaTemp, Protemp 3 Garant and fast set TemPhase, respectively. There was no significant difference between LuxaTemp and Protemp 3 Garant, whereas there was a statistically difference between Protemp 3 Garant and fast set TemPhase, and LuxaTemp and fast set TemPhase (P < .05).
CONCLUSION
The degree of conversion of fast set TemPhase was significantly lower than those of the others. The degree of conversion may be correlated with the rate of polymerization.

Keyword

Degree of conversion; provisional crown and fixed partial denture materials

MeSH Terms

Acrylic Resins
Bisphenol A-Glycidyl Methacrylate
Citrus sinensis
Composite Resins
Crowns
Denture, Partial, Fixed
Fourier Analysis
Methacrylates
Polymerization
Polymers
Spectroscopy, Fourier Transform Infrared
Spectrum Analysis
Acrylic Resins
Bisphenol A-Glycidyl Methacrylate
Composite Resins
Methacrylates
Polymers

Figure

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  Fig. 1. Avatar 360 FTIR Spectrometer used to measure the degree of conversion.

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  Fig. 2. Degree of conversion of the investigated materials.

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