Determination of polymerization shrinkage stress by means of a photoelastic investigation

Ernst, Claus‐Peter; Meyer, G; Klöcker, Kerstin; Willershausen, Brita

doi:10.1016/s0109-5641(03)00109-x

Cited by 69 publications

(46 citation statements)

References 40 publications

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“…19 The epoxy ring opening of the silorane produces volume expansion, which can partially offset the curing contraction resulting from the simultaneous formation of covalent bonds and the reduction in space between adjacent molecules. 19,22,36,37 Additionally, in contrast to the radical polymerization reaction that forms parallel chains and significant reduction in volume with increased chain length, the cationic ring opening polymerization of a multifunctional monomer such as silorane results in a network formation that is accompanied by minimal reduction in volume. 19,37 Alternatively, the chemical composition of the resin matrix of AL is based on a combination of Bis-EMA, bisphenyl glycidylmethacrylate (Bis-GMA), and TEDGMA.…”

Section: Discussionmentioning

confidence: 99%

Effect of C-factor on Microtensile Bond Strengths of Low-Shrinkage Composites

El-Sahn

El-Kassas

El-Damanhoury

et al. 2011

Operative Dentistry

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SUMMARY This study evaluated the microtensile bond strength (μ-TBS) of low-shrinkage composites with their corresponding adhesive systems, Filtek Silorane/Silorane adhesive (SIL, 3M ESPE AG, Seefeld, Germany) and Aelite LS/One-Step Plus (AL, BISCO Inc, Schaumburg, IL, USA) in cavities with different C-factors. Filtek Z250/Adper Single Bond Plus (Z, 3M ESPE, St Paul, MN, USA) was used as a control. Method Standardized Class I cavities were prepared in extracted human molars after removing occlusal enamel. Cavities were assigned into six different C-factors by applying nail polish to four walls, three walls, two walls adjacent to each other, two walls opposite to each other, one wall, or no walls. Resin composites with their corresponding adhesive systems were applied according to manufacturer instructions. Specimens were sectioned to obtain four rectangular beams from the center of the restorations and μ-TBS was measured. Data were analyzed by Weibull survival analysis. Shrinkage stresses of the resin composites were determined after 30 minutes from the start of light-curing using a tensometer testing machine. Flexure elastic modulus was determined using standard procedures, in accordance with ISO 4049. Data for shrinkage stress and elastic modulus were analyzed by one-way analysis of variance followed by a Tukey multiple-comparisons test (p<0.05). Results μ-TBS of both SIL and AL were not affected by different C-factors; however, the bond strength of Z decreased significantly when the C-factor increased. Shrinkage stress results were 0.94±0.1, 1.79±0.18, and 2.14±0.23 MPa for SIL, AL, and Z, respectively. The flexural modulus of both the SIL and the AL was significantly lower than that of Z. Conclusions Increasing C-factor did not negatively affect the bond strength of low-shrinkage composites.

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Section: Discussionmentioning

confidence: 99%

Effect of C-factor on Microtensile Bond Strengths of Low-Shrinkage Composites

El-Sahn

El-Kassas

El-Damanhoury

et al. 2011

Operative Dentistry

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“…Polymerization shrinkage stress data (in MPa) were calculated based on the methodology of Ernst et al 4 Basically, three measurements of the first-order photoelastic fringe obtained from Araldite discs were obtained from each specimen (n = 5) on monochromatic images using UTHSCSA ImageTool software (University of Texas, San Antonio, TX, USA; available without cost from ftp://maxrad6.uthscsa.edu). Shrinkage stress values (σ 0 ) were obtained from the isochromatic ring diameters using the following equation:…”

Section: Photoelastic Measurementsmentioning

confidence: 99%

“…2 Many factors-including some that are related to material composition such as organic matrix composition, initiation system, and amount of inorganic filler-affect the degree of polymerization shrinkage, influencing contraction and strain. [3][4][5] The organic matrices of composites contain different monomers. Recently, a new silorane-based monomer composite was introduced for use in dentistry.…”

Section: Introductionmentioning

confidence: 99%

“…This technique has been used previously to evaluate polymerization shrinkage stress in dental composites. 4,11 These fringes have mathematical relationships and order numbers that are dependent on the load intensity applied to the photoelastic material. 12,13 In this study, stress induced in three experimental and two commercial composites was assessed immediately after photopolymerization and 24 hours and 7 days later.…”

Section: Introductionmentioning

confidence: 99%

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Photoelastic evaluation of the effect of composite formulation on polymerization shrinkage stress

et al. 2012

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We compared polymerization stress in two commercial composites and three experimental composites made using camphorquinone (CQ) and/or phenylpropanedione (PPD) as photoinitiators. The internal surfaces of photoelastic resin discs with cylindrical cavities were roughened and treated with adhesive. Composites were divided into five groups: two commercial composites (Filtek Silorane and Filtek Z250) and three experimental composites with CQ/amine, CQ/PPD/amine, and PPD/amine. Composites were photopolymerized inside cavities, and subjected to photoelastic analysis immediately and at 24 hours and 7 days later using a plane polariscope. Stress created by Silorane (3.08 ± 0.09 MPa) was similar to that of Z250 (3.19 ± 0.13 MPa) immediately after photopolymerization (p > 0.05). After 24 hours and 7 days, Z250 (3.53 ± 0.15 and 3.69 ± 0.10 MPa, respectively) showed higher stress than Silorane (3.19 ± 0.10 and 3.16 ± 0.10 MPa, respectively). Qualitative analysis immediately after photopolymerization showed composite/CQ promoted higher stress than PPD, but stress levels at other evaluated times were statistically similar, varying between 3.45 ± 0.11 MPa and 3.92 ± 0.13 MPa. At 24 hours and 7 days, Silorane created the lowest stress. All photoinitiators created comparable tensions during polymerization.

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“…9 Therefore, a significantly lower polymerization shrinkage and lower stress development occur. 10 However, little is known about the effect associating an intermediate material and a silorane-based composite.…”

Section: Introductionmentioning

confidence: 99%

Influence of an Intermediary Base on the Microleakage of Simulated Class II Composite Resin Restorations

Giorgi

Hernandes

Sugii

et al. 2014

Operative Dentistry

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The use of resin-modified glass ionomer cement as an intermediary base provides lower microleakage, indicating better sealing of the tooth-restoration interface. SUMMARYThe aim of this in vitro study was to qualitatively and quantitatively evaluate the microleakage of Class II cavities restored with a methacrylate-based composite (Filtek Z250, 3M ESPE) or silorane-based composite (Filtek LS, 3M ESPE), varying the application of an intermediary base, using a low-viscosity composite resin (Filtek Z350 Flow, 3M ESPE) or resinmodified glass ionomer cement (RMGIC) (Vitrebond, 3M ESPE) and no intermediary base (control groups). Sixty cavities were prepared on the proximal surfaces of bovine teeth and were randomly divided according to the experimental groups (n=10). Following the restorative procedures and thermocycling, the samples were immersed in methylene blue for two hours. The qualitative evaluation was made using a stereomicroscope, whereby two observers analyzed the infiltration level of the dye within the tooth/filling. Microleakage scores among the groups were compared using the Kruskal-Wallis test followed by the MannWhitney test (p0.05). The samples were then Results from the qualitative analysis showed that there were no statistically significant differences between composites; however, there were significant differences for both composites concerning the intermediary materials, with the lowest values obtained using RMGIC as an intermediary. It is possible to conclude that using RMGIC as an intermediary base provided lower microleakage, indicating better sealing of the tooth-restoration interface.

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Determination of polymerization shrinkage stress by means of a photoelastic investigation

Cited by 69 publications

References 40 publications

Effect of C-factor on Microtensile Bond Strengths of Low-Shrinkage Composites

Effect of C-factor on Microtensile Bond Strengths of Low-Shrinkage Composites

Photoelastic evaluation of the effect of composite formulation on polymerization shrinkage stress

Influence of an Intermediary Base on the Microleakage of Simulated Class II Composite Resin Restorations

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