Influence of the base and diluent methacrylate monomers on the polymerization stress and its determinants

Abstract

The aim of this study was to evaluate the effect of the association between bisphenol-A diglycidyl dimethacrylate (BisGMA) or its ethoxylated version (BisEMA) with diluents derived from the ethylene glycol dimethacrylate (EGDMA), with increasing number of ethylene glycol units (1: EGDMA, 2: DEGDMA, 3: TEGDMA, or 4: TETGDMA), or trimethylol propane trimethacrylate (TMPTMA) or 1,10-decanediol dimethacrylate (D 3 MA) on polymerization stress, volumetric shrinkage, degree of conversion, maximum rate of polymerization (Rp max ), and elastic modulus of experimental composites. BisGMA containing formulations presented lower shrinkage and stress but higher modulus and Rp max than those containing BisEMA. TMPTMA presented the lowest stress among all diluents, as a result of lower conversion. EGDMA, DEGDMA, TEGDMA, and TETGDMA presented similar polymerization stress which was higher than the stress presented by D 3 MA and TMPTMA. D 3 MA presented similar conversion when copolymerized with both base monomers. The other diluents presented higher conversion when associated with BisEMA. EGDMA showed similar shrinkage compared with DEGDMA and higher than the other diluents. The lower conversion achieved by TMPTMA did not jeopardize its elastic modulus, similar to the other diluents. Despite the similar conversion presented by D 3 MA in comparison with EGDMA and DEGDMA, its lower elastic modulus may limit its use. Rather than proposing new materials, this study provides a systematic evaluation of off the shelf monomers and their effects on stress development, as highlighted by the analysis of conversion, shrinkage and modulus, to aid the optimization of commercially available materials.

Solvent Degradation and Polymerization Shrinkage Reduction of Resin Composites Using Isobornyl Methacrylate

“…As observed in the results, reducing TEGDMA concentration using IBOMA as a codiluent monomer did not affect the DC, FS, FM, KHN or SD of the material (p≥0.05) and, actually reduced gap formation caused by polymerization shrinkage in comparison to the control containing only TEGDMA as the only diluent monomer (p≤0.05). Due to the fact that the IBOMA is a monomethacrylate monomer and do not contribute to polymer crosslinking as dimethacrylate monomers do (10,11), it can affect crosslinking but also delay the vitrification process, thus reducing shrinkage as observed.…”

“…However, although monomethacrylates, such as IBOMA, might increase the monomeric conversion (10) and reduce the cytotoxic potential (1) of resin materials, the results of the mechanical properties can be significantly reduced in comparison to the dimethacrylates (10,11). This would occur due to the fact that monomethacrylate monomers, such as the IBOMA, do not contribute to polymer crosslinking as dimethacrylate monomers do (10,11). However, combining dimethacrylate and monomethacrylate monomers might be the key for not necessarily affecting crosslinking but delaying vitrification, and possibly reducing shrinkage as well.…”

Isobornyl methacrylate as diluent co‐monomer on physical‐mechanical properties of dental resin composites

“…Therefore, the Bis-GMA/IBOMA resins should also present the same curing potential and reduced volumetric shrinkage values as the Bis-GMA/ TEGDMA (60/40 wt%) resin, which would indicate good durability of the restorations. 11,[23][24][25] A possible incompatibility between diluent monomers (TEGDMA e IBOMA) could explain the lowest values of volumetric shrinkage and degree of conversion for the resin blends containing these monomers. IBOMA is a monomethacrylate with only one carbon double-bond (aliphatic cyclic structure).…”

Protein-repellent and antibacterial functions of a calcium phosphate rechargeable nanocomposite

“…DMAHDM is a monomethacrylate containing a long pendant alkyl chain and one reactive methacrylate group. The reduced elastic modulus in DMAHDM-containing samples may be due to the disruption of the methacrylate network and slightly lower crosslink density with the inclusion of monofunctional methacrylates in a resin consisting of difunctional monomers [47]. Additionally, DMAHDM may slightly reduce the degree of vinyl conversion, which also would decrease the elastic modulus.…”