Unreacted Methacrylate Groups on the Surfaces of Composite Resins

Vankerckhoven, H.; Lambrechts, Paul; Beylen, Marcel Van; Davidson, C.L.; Vanherle, Guido

doi:10.1177/00220345820610062801

Cited by 164 publications

(108 citation statements)

References 10 publications

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“…During incremental layering, an oxygen-inhibited layer makes reliable adhesion of subsequent increments possible [10,30]. Adhering a new RBC to an existing one presents a different challenge because of the absence of an oxygeninhibited layer.…”

Section: Discussionmentioning

confidence: 99%

“…Despite the presence of unreacted methacrylate groups after the polymerization, the amount of unsaturated double bonds diminishes with ageing and reduces the resin adhesion potential [10][11][12][13]. Different periods of water storage and thermocycling are some of the methods used to simulate the ageing process of dental materials in in vitro studies [8,9,13].…”

Section: Introductionmentioning

confidence: 99%

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Repair bond strength of microhybrid, nanohybrid and nanofilled resin composites: effect of substrate resin type, surface conditioning and ageing

et al. 2012

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OBJECTIVES: This study evaluated the microtensile bond strength (MTBS) of non-aged and aged resin-based composites (RBC) (nanohybrid and nanofilled) after two surface conditioning methods, repaired using the composite of the same kind or a microhybrid composite. MATERIALS AND METH-ODS: Nanohybrid (Tetric EvoCeram-TE) and nanofilled (Filtek Supreme-FS) RBC blocks (5 × 5 × 6 mm) (N = 128) were fabricated and randomly divided into two groups: (a) no ageing (control group) and (b) ageing (5.000 thermocycling, 5-55°C). RBC surfaces were polished by up to 1,200-grit silicone carbide papers and conditioned with either (a) air abrasion with 30-m SiO(2) particles (CoJet Sand) for 4 s + silane coupling agent (ESPE-Sil) + adhesive resin (VisioBond) (n = 16) or (b) adhesive application only (Multilink A+B for TE; Adper ScotchBond 1XT for FS) (n = 16). In half of the groups, repair resin of the same kind with the RBC and, in the other half, a different kind of composite (microhybrid, Quadrant Anterior Shine-AS) with its corresponding adhesive (Quadrant UniBond) was used. The specimens were submitted to MTBS test (0.5 mm/min). Data were analysed using three-way ANOVA and Tukey's tests. Degree of conversion (DC) of non-aged and aged resin composites (TE, FS) (n = 3 per group) was measured by micro-Raman analyses. RESULTS: RBC type (p = 0.001) and ageing affected the MTBS results significantly (p = 0.001). Surface conditioning type did not show significant difference (p = 0.726), but less number of pre-test failures was experienced with the CoJet system compared to adhesive resin application only. Repair strength on aged TE showed significantly less (p < 0.05) MTBS than for FS. FS repaired with the same kind of RBC and adhesive resin presented the highest cohesive failures (43 %). DC was higher for TE (71 %) than for FS (58 %) before ageing. CONCLUSION: On the aged RBCs, less favourable repair strength could be expected especially for nanohybrid composite. For repair actions, RBC surface conditioning could be accomplished with either adhesive resin application only or with CoJet system, providing that the latter resulted in less pre-test failures. CLINICAL RELEVANCE: Clinicians could condition the resin surface prior to repair or relayering with either CoJet system or adhesive resin application only, depending on the availability of the system. Abstract Objectives This study evaluated the microtensile bond strength (MTBS) of non-aged and aged resin-based composites (RBC) (nanohybrid and nanofilled) after two surface conditioning methods, repaired using the composite of the same kind or a microhybrid composite. Materials and methods Nanohybrid (Tetric EvoCeram-TE) and nanofilled (Filtek Supreme-FS) RBC blocks (5× 5×6 mm) (N0128) were fabricated and randomly divided into two groups: (a) no ageing (control group) and (b) ageing (5.000 thermocycling, 5-55°C). RBC surfaces were polished by up to 1,200-grit silicone carbide papers and conditioned with either (a) air abrasion with 30-μm SiO 2 particles (CoJet Sand) for 4 s ...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Repair bond strength of microhybrid, nanohybrid and nanofilled resin composites: effect of substrate resin type, surface conditioning and ageing

et al. 2012

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“…Quickly, the compound movements of the showed monomers were measured in chloroform-d at 35°C at 125 and 500 MHz, utilizing tetramethylsilane (TMS) as an inward standard, as revealed. 1 H-NMR compound move information for TEGDMA, bis-GMA and UDMA [1]. Additionally, the 13 C-NMR concoction movements of EGDMA, TEGDMA and bis-GMA were resolved in CDCl 3 utilizing a JEOL ALPHA 500 NMR spectrometer [11][12][13].…”

Section: Nmr Spectramentioning

confidence: 99%

“…Acrylates were positioned as having the most elevated GSH reactivity, subsequently plainly recommending the solid impact of the substitution design (H) on the α-carbon, contrasted with that (CH 3 ) on the α-carbon for methacrylates (Figure 1). 1 H-NMR concoction movements are additionally influenced by the β-electron thickness of the joined carbon. In spite of the fact that the compound move extent for 1 H-NMR is littler than that for 13 C-NMR, assurance of the substance shifts from 1 H-NMR could be significantly less demanding and more helpful than from 13 C-NMR.…”

Section: Compoundsmentioning

confidence: 99%

“…By and large, methacrylate monomers don't polymerize totally in air since oxygen goes about as a biradical and stifles polymerization, leaving unreacted methacrylate bunches on the gum surface [1]. In this way unpolymerized methacrylates in dental materials are an essential element bringing on bothering and unfavorably susceptible responses in the oral hole [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

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Relationships between the Reduced Glutathione (GSH) Reactivity of Dental Methacrylates, Michael-reaction Acceptors and their 13C-NMR Chemical Shift of -Carbons

Fujisawa¹

2017

Periodon Prosthodon

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Abstract(Meth)acrylates, α,β-unsaturated esters are Michaelresponse acceptors and have concentrated on antagonistic wellbeing exercises, for example, oral sicknesses and hypersensitive contact dermatitis. A connection between decreased glutathione (GSH) reactivity and lethality for (meth)acrylate monomers has been set up. To foresee the GSH reactivity of dental methacrylate monomers, the 13 C-NMR compound movements of β-carbon (δ Cβ) and the 1 H-NMR movements of the proton joined to the β-carbon (δ H a , δ H b ) were decided for a preparation set of acrylate and methacrylate monomers having diverse nucleophiles. Writing information for monomer GSH reactivity were utilized for expectation of the GSH reactivity of dental methacrylates. Critical direct connections between GSH reactivity (log K) and δ Cβ or δ Ha were watched (p<0.001). A worthy relationship for the LD 50 in mice of acrylates and methacrylates was seen as far as log K (p<0.005, exception: HEMA). The oral mouse LD 50 values for some dental dimethacrylates, two Michael-response acceptors (two-twofold bonds, two β-carbons) were assessed by direct relapse bend fitting of GSH reactivityharmfulness reaction information. The present discoveries propose that NMR spectra may be helpful for anticipating the danger of dental methacrylates.

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Cytotoxicity of urethane dimethacrylate composites before and after aging and leaching

Mohsen

Craig

Hanks

1998

J. Biomed. Mater. Res.

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The in vitro cytotoxicity of urethane dimethacrylate composites cured at different times by visible light and after different aging times and extraction treatments was evaluated using succinic dehydrogenase activity in the mitochondria of a fibroblastic cell line to reflect cell viability. In addition, extractable chemicals associated with cell response were identified. The composite samples were tested untreated, polished, or extracted with water or 75% ethanol-water. Balb/c 3T3 fibroblasts were used as the cell culture system while MTT-formazan production was used as the toxicity parameter. Cell viability was calculated as a percentage of Teflon controls. Identification of the chemicals was measured by extracting the composites with 75% ethanol-water, separating the extract by HPLC, and identifying the fractions with mass spectroscopy. In general, cell viability increased continuously with curing time for differently treated samples at high aging times (288 h) while it decreased when the composites were not aged (0 h). In addition, for 75% ethanol or water-extracted composites, cell viability increased within the first 24 h of aging and reached a plateau after 72 h. Lowest cytotoxicity occurred when the samples were extracted with the 75% ethanol solution. The highest cytotoxic effects were found when the samples were untreated. Slightly reduced cytotoxic effects were seen with polished composites. The results suggest that curing the light-activated composites for a minimum of 150 s and post-curing for 24 h is required to attain comparable biocompatibility with the Teflon control. Removing the oxygen-inhibited layer from these composites decreased the cytotoxicity by 33% while extracting the composites with 75% ethanol-water decreased it by 77%. Chemicals released from the surface accounted for approximately 40% of cellular response while about 60% of the response was due to chemical components released from the bulk. The primary leachable component from the composites was UDMA monomer. Small quantities of 1,6 hexane diol methacrylate, camphoroquinone, and 2,4,6-tritertiarybutyl phenol also were found.

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Unreacted Methacrylate Groups on the Surfaces of Composite Resins

Cited by 164 publications

References 10 publications

Repair bond strength of microhybrid, nanohybrid and nanofilled resin composites: effect of substrate resin type, surface conditioning and ageing

Repair bond strength of microhybrid, nanohybrid and nanofilled resin composites: effect of substrate resin type, surface conditioning and ageing

Relationships between the Reduced Glutathione (GSH) Reactivity of Dental Methacrylates, Michael-reaction Acceptors and their 13C-NMR Chemical Shift of -Carbons

Cytotoxicity of urethane dimethacrylate composites before and after aging and leaching

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