Table 1.
Summary of studies included in the systematic review
| Studies | Monomer and its property | Availability | Modified MMA in vol/wt % | Material, trade name and curing regimen | P/L ratio | Evaluated properties* | Results and conclusions |
|---|---|---|---|---|---|---|---|
| Hayashi et al.[26] (2003) | Perfluoro octylethyl acrylate (C8F) Hydrophobic monomer | Monomer: Purchased Polymer: Synthesized by suspension polymerization | 0 and 25 wt% | Heat-cured in presence of 0.045 g of α-α′-azobis isobutyronitrile (AIBN) at 70ºC for 6 hours and then at 100ºC for 0.8 hour | 2:1 | CA Tg KH TS MA | Increase in the CA and Tg. No significant difference in KH. Decrease in TS. C8F reduced the MA |
| Kubota et al.[27] (2005) | Perfluoro (butylethyl [C4F], hexylethyl [C6F], octylethyl [C8F], decylethyl [C10F]) acrylates Hydrophobic monomers | Monomer: Purchased. Polymer: Synthesized by suspension polymerization | 0 and 25 wt% | Heat-cured in presence of 0.015 wt% of AIBN at 70ºC for 6 hours and then at 100ºC for 0.8 hours | 2:1 | Tg KH TS | Increase in the carbon chain length increased Tg and decreased KH and TS. However, this research concluded that the fluoromonomer-added denture base resins are acceptable for clinical use with regard to mechanical properties |
| Kobayashi et al.[28] (2006) | C4F, C6F, C8F and C10F Hydrophobic monomers | Monomers: Purchased. Polymer: Synthesized by suspension polymerization | 0 and 25 wt% | Heat-cured in presence of 1.5 g of α-α′-azobis isobutyronitrile [AIBN] at 70ºC for 6 hours and then at 100ºC for 0.8 hours | 2:1 | CA MA | Increase in the carbon chain length increased the CA and decreased MA |
| Kurata et al.[29] (2007) | A. Fluoro-monomers: 1. α-Trifluoro methacrylic acid t-butyl [MAF-TBE]. 2. α-Trifluoro methacrylic acid 2-methyl-2-adamantyl (MAF-MAE). 3. 2-Trifluoro methyl norbornene-2-carboxylic acid t-butyl (MAF-TBN) B. Styrene monomers: 1. p-t-Butoxy styrene (PTBS). 2. p-Acetoxy styrene (PACS). 3. p-Ethoxy ethoxystyrene (PEES) |
Purchased | 0, 10, 20, 30 mol% | Bulk polymerization. Heat-cured at 51ºC for 24 hours in a water bath in the presence of 50 mg of BPO followed by 100ºC for 1 hour in a dry oven | N/A | CS FS WS | CS and FS decreased with increase in mol% of substituted monomers whereas MAF-TBN and PEES showed least values. Fluoro- and styrene monomers decreased the WS with increase in mol%. In all the tests, MAF-TBN at 30 mol% showed rubber-like consistency indicating poor polymerization characteristics |
| Cunha et al.[30] (2009) | Fluoralkyl methacrylate (FMA) Hydrophobic monomer | Purchased | 0, 10, 20 vol% | Lucitone 550 Heat-cured at 73°C for 90 minutes and 100°C for 30 minutes | 21 g/ 10 mL | FS YM Ra | Ra was unaffected. Addition of FMA decreased FS and YM regardless of the tested concentration. However, this decrease may be clinically acceptable |
| Dhir et al.[31] (2007) | Phosphate-containing monomer | Not mentioned | 0, 10 and 20 vol% | Lucitone 199 Heat-cured at 73°C for 90 minutes and 100°C for 30 minutes | 3:1 | FS WS solubility ColS and staining | Increase in the phosphate monomer concentration decreased the FS and increased WS and solubility. No difference was found with respect to ColS and staining |
| Puri et al.[32] (2008) | Ethylene glycol methacrylate phosphate (EGMP) | Purchased | 0, 10, 15, 20 vol% | Lucitone 199 Heat-cured at 74°C for 9 hours | 3:1 | IS FT CA | Addition of EGMP did not adversely affect IS and FT. However, CA decreased with increase in vol% |
| Raj et al.[33] (2011) | Methallyl phosphate (MAP) Antimicrobial monomer | Monomer: Synthesized Polymer: Synthesized by suspension/ bead polymerization | 0, 5, 10, 15, 20, 25% | Autopolymerized with 1.2 g of BPO and 0.75 mL of dimethyl para toluidine | N/A | Adhesion assay | MAP inhibited the adhesion and colonization of Candida albicans |
| Park et al.[34] (2003) | Methacrylic acid (MAA). Antimicrobial monomer | Purchased | 0, 5, 10, 20% | Autopolymerized with 1 wt % of BPO and 0.5 vol % of N,N- dimethyl aniline in water at 55 ± 1°C under air pressure of 300 kPa for 15 minutes | 3:1 | MA CA | MA and CA decreased with increasing concentrations of MAA |
| Azevedo et al.[35] (2010) | MAA Antimicrobial monomer | Purchased | 0, 10, 20, 50 vol % | Lucitone 550 Heat-cured at 73°C for 90 minutes and 100°C for 30 minutes | 21 g/ 10 mL | VHRaFS | At 50 vol%, VH decreased. A decreasing Ra was found in all concentrations and improved FS |
| Jain et al.[36] (2013) | MAA Antimicrobial monomer | Purchased | 0, 12, 16, 20 % | Trevalon Heat-cured according to manufacturer’s instruction | 3:1 | FS | FS decreased with increasing concentrations of MAA |
| Al-Ali et al.[37] (2015) | MAA, ethyl acrylate (EA) and butyl methacrylate (BMA) | Purchased. | 0, 5, 10, 15% | Vertex Heat-cured from room temperature to 100°C and maintained for 30 minutes | 22 g/ 10 mL | CP | All the monomers successfully co-polymerized with MMA at all concentrations |
| Gupta et al.[38] (2017) | MAA Antimicrobial monomer | Purchased | 0, 15, 20, 25% | DPI Heat-cured at 74°C for 8 hours and then at 100°C for 30 minutes | 2.5:1 | FS MA | Addition of MAA did not affect FS. However, with increase in concentration and number of days, decreased the CFU |
| Sujitha et al.[39] (2018) | MAA Antimicrobial monomer | Purchased | 0, 10, 20 vol% | DPI Heat-cured according to manufacturer’s instruction | 3:1 | FS, Ra | Decreased FS and improved Ra with increasing concentrations of MAA |
| Spasojević et al.[40] (2012) | Dimethyl itaconate (DMI) and Di-n-butyl itaconate (DBI) | DMI: Purchased DBI: Synthesized | 0, 2.5, 5.0, 7.5, 10 wt%. | Biocryl Heat-cured at 100°C for 30 minutes in the water bath | 2:1 | RM WS DC | RM decreased with increased concentrations of itaconates. WS decreased with increased concentrations of itaconates. DC increased for DBI at 7.5 and 10% |
| Spasojević et al.[41] (2015) | DMI and DBI | DMI: Purchased DBI: Synthesized | 0, 2.5, 5.0, 7.5, 10 wt% | Biocryl Heat-cured at 100°C for 30 minutes in the water bath | 2:1 | CP Tg TS SH IS | CP was confirmed with PMMA. Tg, TS and IS decreased with increased concentrations of itaconates. SH was unaffected with DMI whereas increased with increased concentration of DBI |
| Spasojević et al.[42] (2015) | Di-tetra hydrofurfuryl itaconate (DTHFI) | Synthesized | 0, 2.5, 5.0, 7.5, 10 wt% | Biocryl Heat-cured at 100°C for 30 minutes in the water bath | 2:1 | RM, CP, WS, Tg, TS, SH, IS | RM decreased with increased concentrations of itaconates. CP was confirmed with PMMA. WS decreased with increased concentrations of itaconates. Tg, TS and SH decreased with increased concentrations of itaconates. IS was unaffected. |
| Paleari et al.[43] (2011) | 2-tert-butyl aminoethyl methacrylate (TBAEMA) Antimicrobial monomer | Purchased | 0.00, 0.50, 1.00, 1.50, 1.75, 2.00% | Lucitone 550 Heat-cured at 73°C for 90 minutes and 100°C for 30 minutes | 21 g/10mL | FS | Increasing TBAEMA concentrations reduced the FS |
| Rodriguez et al.[5] (2013) | TBAEMA Antimicrobial monomer | Purchased | 0, 1, 2, 3, 4% | Onda-cryl Microwave curing. Cured for 3 minutes at 320 W + 4 minutes at 0 W + 3 minutes at 720 W | 14 g/ 7 mL | N2 ratio CP Tg FS | Amine group indicates antimicrobial activity. TBAEMA co-polymerizes with MMA. Both Tg and FS decreased with increased concentration of TBAEMA |
| Mirizadeh et al.[44] (2018) | N,N-dimethyl aminoethyl methacrylate- octyl bromide (DMAEMA-OB). Quaternized ammonium antimicrobial monomer (QAM) | Synthesized | 0, 8, 10, 12 wt% | Vertex Heat-cured at 70ºC for 1 hour and at 100ºC for 2 hours (dry heat) | 50 g/ 25 mL | CFU (direct contact test) FS WS | QAM was significantly effective against gram- positive and gram-negative bacteria and fungi. FS decreased with increasing concentrations of QAM. WS increased with increasing concentrations of QAM |
| Regis et al.[45] (2011) | Methacryloyl oxyundecyl pyridinium bromide (MUPB) Antimicrobial monomer | Synthesized | 0.0, 0.3, 0.6 wt% | Lucitone 550 Heat-cured at 73°C for 90 minutes and 100°C for 30 minutes | 21g/ 10mL | VH FS Ra ColS | Reinforcing MUPB with MMA did not alter the VH. FS significantly decreased at 0.6% concentration. Ra ColS were not affected at 0.3 or 0.6% |
| Aydogan Ayaz and Durkan .[46] (2013) | Acrylamide monomer (AA) | Purchased | 0, 5, 10, 15, 20%. | QC 20 Heat-cured in a thermally controlled autoclave device at 60°C for 30 minutes, and further cured at 130°C for 20 minutes. Acron MC: Microwave irradiation at 500 W for 3 minutes | N/A | FS FM CP | FS and FM increased with increased concentrations of AA. Successful copolymerization of AA with PMMA |
| Umemoto and Kurata.[47] (1997) | Norbonyl methacrylate (NBMA) and phenyl methacrylate (PHMA). Both are hydrophobic monomers | Synthesized | 0, 10, 20, 30, 40 wt% | Bulk polymerization Heat-cured at 55ºC for 24 hours in water bath in the presence of 0.5 wt% of benzoyl peroxide (BPO) followed by 100ºC for 1 hour in a dry oven | N/A | CS WS FS DMTA PS | Addition of NBMA and PHMA to MMA decreased WS and improved mechanical properties. Showed less PS than PMMA |
| Kim et al.[48] (2007) | Polyhedral oligosil sesquioxane (POSS) | Purchased | 0 and 1.44% | Paladent 20 Curing regimen not specified | N/A | In vitro cytotoxicity tests: 1. MTT assay 2. Agar overlay test 3. Mutagenesis assay | In all assays, addition of POSS with MMA showed less cytotoxicity than the control |
| Kawaguchi et al.[49] (2011) | Methacrylated dendrimer (DD1) compared with ethylene glycol di methacrylate (EGDMA) Cross-linker | Monomer: Synthesized Polymer: Synthesized | 1.1, 2.3, 4.6, 6.9, 9.1 vol% of both monomers | Bulk polymerization 2% BPO was added to powder and mixed with monomer and polymerized in distilled water at 55°C under pressure of 0.4 MPa for 20 minutes | 10 g/ 7 mL | FSFMVH | Addition of DD1 improved only FM. FS and VH remained unaffected. The effect of vol % was significant only on FS |
| Aoyagi et al.[50] (2012) | 1,3-bis(3-methacryloxy propyl)-1,1,3,3- tetramethyl disiloxane (BMPMS) | Purchased | 0, 10, 30, 50, 70 mol% | Bulk polymerization Heat-cured at 53ºC for 5 days in a water bath in presence of 0.5 mass% of BPO followed by 100ºC for 1 hour in dry oven | N/A | WS WSol | WS and W Sol decreased with increasing concentrations of BMPMS |
| Al-Husayni et al.[51] (2014) | Silver nitrate (AgNO3) | Synthesized | 9.375, 15, 30, 60, 120, 150, 300, 600, 900 ppm | Ivoclar vivadent Heat-cured. Regimen not specified | 2.25 g/LmL | IS FS TS | 1. IS was high at 60 ppm. In the rest of concentrations, IS was not affected. 2. FS and TS decreased with increase in ppm. 3. Discoloration was observed at 300 ppm |
| Jiao et al.[52] (2015) | N-acetyl cysteine (NAC) | Purchased | 0, 0.15, 0.3, 0.6, 0.9 wt% | Unifast trad. Autopolymerized resin | 1 g per 0.5 mL | MTT assay DegC FS VH Ra | Higher cell viability with NAC. DegC reduced except at 0.15% of NAC. FS decreased with increasing concentrations of NAC. VH was unaffected at 0.15% beyond which it decreased. Ra was affected at a concentration beyond 0.3% |
*CS = compressive strength, WS = water sorption, FS = flexural strength, DMTA = dynamic mechanical thermal analysis, PS = polymerization shrinkage, CA = contact angle, Tg = glass transition temperature, KH = knoop hardness, TS = tensile strength, MA = microbial adhesion, MTT = tetrazolium, ColS = color stability, FT = fracture toughness, YM = Young’s modulus, Ra = surface roughness, VH = Vicker hardness, ZI = zone of inhibition, TB= = Trypan blue, FM = flexure modulus, WSol = water solubility, CP = co-polymerization, CFU = colony-forming unit, RM= residual monomer, DC = diffusion coefficient, SH = shoreD hardness; DegC = degree of conversion