796 Extent of polymerization of experimental adhesive blends containing anhydrous QAMs

Friday, March 23, 2012: 2 p.m. - 3:15 p.m.
Presentation Type: Poster Session
L. FONTANIVE1, L. BRESCHI1, K. AGEE2, A. TEZVERGIL-MUTLUAY3, R. DI LENARDA1, F. RUEGGEBERG4, F.R. TAY2, D. PASHLEY2, and M. CADENARO1, 1Department of Medical Sciences, University of Trieste, Trieste, Italy, 2Dept. Oral Biology, Georgia Health Sciences University, Augusta, GA, 3University of Turku, Turku, Finland, 4Oral Rehabilitation, Georgia Health Sciences University, Augusta, GA

Objectives: This study examined the effect of anhydrous quaternary ammonium methacrylates (QAMs) on the extent of polymerization (Ep) of experimental light-cured adhesive resins by using differential scanning calorimetry (DSC). The hypothesis tested was that polymerization kinetics of the adhesive blends was not affected QAMs addition.

Methods: Light-curing experimental adhesive blends containing 70wt% resin (R2: 70wt% bisGMA, 28.75wt% TEGDMA; R3: 70wt% BisGMA, 28.75wt% HEMA; R4: 40wt% BisGMA, 30wt% TCDM, 28.75wt% TEGDMA; R5: 40wt% BisGMA, 30wt% BisMP, 28.75wt% HEMA), 20wt% ethanol (ETOH) and 10wt% QAMs in their anhydrous form (ATA or MCMS or METMAC) were prepared. All blends included 1wt% EDMAB+0.25wt% CQ. Resins with no QAMS were used as a control (80wt% R2-R5+20wt% ETOH). A DSC device was used to measure the Ep of the experimental adhesive blends. Curing was performed in the DSC chamber with a halogen curing light for 40s (600 mW/cm2) at 35C under a nitrogen atmosphere. Data were analyzed by two-way ANOVA and Tukey's post hoc test.

Results: DSC data showed that Ep of all tested resins was higher when ATA was added (p<0.05) (Table 1). Ep of R5 was increased by QAMs addition independently from QAMs type (p<0.05).

Table 1. Means and standard deviations of Ep of the tested resin blends.

Resin blend

Ep (%)

80wt%R2+20wt%ETOH

595ab

80wt%R3+20wt%ETOH

635ab

80wt%R5+20wt%ETOH

607a

70wt%R2+20wt%ETOH+10wt%ATA

713bc

70wt%R3+20wt%ETOH+10wt%ATA

757c

70wt%R5+20wt%ETOH+10wt%ATA

662bc

70wt%R2+20wt%ETOH+10wt%MCMS

675bc

70wt%R3+20wt%ETOH+10wt%MCMS

702abc

70wt%R5+20wt%ETOH+10wt%MCMS

752abc

70wt%R2+20wt%ETOH+10wt%METMAC

643ab

70wt%R3+20wt%ETOH+10wt%METMAC

697abc

70wt%R5+20wt%ETOH+10wt%METMAC

696abc

Same superscript letters indicate no statistical difference (p>0.05).

Conclusions: The tested hypothesis was partially rejected since QAMs addition increased the Ep of some of the tested resin blends when QAMs were added. Further studies are needed to clarify if QAMs addition can affect the properties of adhesive resins. 

Supported, in part, by grants: FIRB RBAP1095CR, and PRIN 2009SAN9K5 and 2009FXT3WL from MIUR, Italy, R01DE015306 to DHP (PI), and #8126472 from the Academy of Finland to AT-M (PI).

This abstract is based on research that was funded entirely or partially by an outside source: FIRB RBAP1095CR and PRIN 2009SAN9K5 and 2009FXT3WL from MIUR, Italy, R01DE015306 to DHP (PI), and #8126472 from the Academy of Finland to AT-M (PI)

Keywords: Adhesion, Polymerization and Polymers