Effect of a non-thermal, atmospheric-pressure, plasma brush on conversion of model self-etch adhesive formulations compared to conventional photo-polymerization

Abstract

Objective To determine the effectiveness and efficiency of non-thermal, atmospheric plasmas for inducing polymerization of model dental self-etch adhesives. Methods The monomer mixtures used were bis-[2-(methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA), with mass ratios of 70/30, 50/50 and 30/70. Water was added to the above formulations: 10–30 wt%. These monomer/water mixtures were treated steadily for 40 s under a non-thermal atmospheric plasma brush working at temperatures from 32° to 35°C. For comparison, photo-initiators were added to the above formulations for photo-polymerization studies, which were light-cured for 40 s. The degree of conversion (DC) of both the plasma- and light-cured samples was measured using FTIR spectroscopy with an attenuated total reflectance attachment. Results The non-thermal plasma brush was effective in inducing polymerization of the model self-etch adhesives. The presence of water did not negatively affect the DC of plasma-cured samples. Indeed, DC values slightly increased, with increasing water content in adhesives: from 58.3% to 68.7% when the water content increased from 10% to 30% in the adhesives with a 50/50 (2MP/HEMA) mass ratio. Conversion values of the plasma-cured groups were higher than those of light-cured samples with the same mass ratio and water content. Spectral differences between the plasma- and light-cured groups indicate subtle structural distinctions in the resultant polymer networks. Significance This research if the first to demonstrate that the non-thermal plasma brush induces polymerization of model adhesives under clinical settings by direct/indirect energy transfer. This device shows promise for polymerization of dental composite restorations having enhanced properties and performance.

Non-thermal atmospheric plasmas in dental restoration: Improved resin adhesive penetration

“…This explains observations that DC improvement was especially pronounced in the interface region and at locations close to the interface (i.e., within the adhesive layer close to dentin surface). Moreover, plasma-induced polymerization also showed advantage in that it is less dependent on water content 40 as compared to free radical photopolymerization. This could be beneficial to achieve an optimal DC at a location with considerable water or dentinal fluids presence, such as in the interface region.…”

Synthesis of fluorinated dimethacrylate monomer and its application in preparing Bis-GMA free dental resin

“…Therefore, DC, VS, WS, SL, FS, FM, and fracture energy of new FUDMA/ TEGDMA resin system were investigated and compared with Bis-GMA/TEGDMA resin system. The DC of a resin depends on the chemical structure of the monomer (Sideridou et al, 2002), nature and concentration of photoinitiation system (He et al, 2008;Shin and Rawls, 2009;Ge et al, 2015), and polymerization conditions like atmosphere (Chen et al, 2012), temperature (Jafarzadeh-Kashi et al, 2014), light intensity (Jafarzadeh-Kashi et al, 2014;Lovell et al, 2003), irradiation time (Tarle et al, 2015), curing methods (Costa et al, 2011) and so on. In this research, the difference in DC between FUDMA/TEGDMA and Bis-GMA/ TEGDMA resins was due to the difference in structure between FUDMA and Bis-GMA, for all the other conditions were kept the same with each other.…”

Adhesive Bonding to Computer-aided Design/Computer-aided Manufacturing Esthetic Dental Materials: An Overview

“…41 The MDP bonds directly to the zirconia surface forming a covalent bond between oxygen, phosphorus, and zirconia. 50,51 Organophosphate monomers contain polymerizable functional groups that can polymerize with the matrix of methacrylate-based resin materials. 50 Air abrasion at a moderate pressure followed by using MDP-containing primers and/or resin cements may ensure long-term durable bonding to zirconia ceramic.…”

“…50,51 Organophosphate monomers contain polymerizable functional groups that can polymerize with the matrix of methacrylate-based resin materials. 50 Air abrasion at a moderate pressure followed by using MDP-containing primers and/or resin cements may ensure long-term durable bonding to zirconia ceramic. 33 Recently, MDPcontaining universal adhesive has shown promising results enhancing resin-zirconia bond strength.…”

“…12,14 Plasmas can be defined as partially ionized gases containing highly reactive particles, such as electronically excited atoms, molecules, and free radical species. 50 Based on gas temperature, plasmas can be categorized into two main types: Thermal (high-temperature) and nonthermal (low-temperature or cold) plasmas. 52 Nonthermal plasma surface treatment of Y-TZP resulted in significantly higher bond strength values to the air abrasion and/or phosphate primer.…”