Abstract:The organic phase of resin composites is constituted by dimethacrylate resins, the most common monomers being the bisphenol A diglycidildimethacrylate (BisGMA), its ethoxylated version (BisEMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). This study compared the homopolymers formed from the monomers used in restorative dental composites in terms of their degree of conversion (DC) and reaction kinetics (by near infra-red spectroscopy, n=3), mechanical properties (flexural modu… Show more
“…2 The physicochemical and mechanical properties of such polymers depend on the degree of conversion (DC) and definitive network structure. 3 In addition, the type of monomer has a significant influence on the polymerization reaction, mechanical properties, and water sorption of RBCs. 4 The durability and performance of bulk-fill RBCs can be evaluated by characterization of their mechanical properties.…”
Aim:The aim was to perform comparative analysis of bioactive, contemporary bulk-fill resin-based composites (RBCs) and conventional glass-ionomer materials for flexural strength (FS), diametral tensile strength (DTS), and Vickers hardness number (VHN) in the presence of thermocycling.
Materials and methods:Five restorative materials [Tetric N-Ceram Bulk Fill; smart dentin replacement (SDR) Flowable Material; Bioactive restorative material (ACTIVA Bulk Fill); Ketac Universal Aplicap; and GC Fuji II] were evaluated for DTS, FS, and VHN. Half the samples in each material group were thermocycled. The DTS was performed under compressive load at a cross-head speed of 1.0 mm/min. The FS was assessed by three-point bending test at a cross-head speed of 0.5 mm/min. The VHN was determined using a Vickers diamond indenter at 50 gf load for 15 seconds. Differences in FS, DTS, and VHN were analyzed using analysis of variance (ANOVA) and Tukey post hoc tests at α = 0.05 level of significance.Results: N-Ceram, ACTIVA, and SDR demonstrated the highest and comparable (p > 0.05) FS. The SDR had the highest DTS value (141.28 ± 0.94), followed by N-Ceram (136.61 ± 1.56) and ACTIVA (129.05 ± 1.78). Ketac had the highest VHN value before and after thermocycling.
Conclusion:ACTIVA showed mechanical properties (FS and DTS) comparable with bulk-fill resin composite materials. ACTIVA showed potential for durability, as VHN was comparable post-thermocycling.Clinical significance: Bioactive materials showed acceptable DTS and FS values. However, hardness was compromised compared with included materials. ACTIVA Bulk Fill shows potential for dentin replacement but it needs to be covered with a surface-resistant restorative material. Further studies to improve surface characteristics of ACTIVA Bulk Fill are recommended.
“…2 The physicochemical and mechanical properties of such polymers depend on the degree of conversion (DC) and definitive network structure. 3 In addition, the type of monomer has a significant influence on the polymerization reaction, mechanical properties, and water sorption of RBCs. 4 The durability and performance of bulk-fill RBCs can be evaluated by characterization of their mechanical properties.…”
Aim:The aim was to perform comparative analysis of bioactive, contemporary bulk-fill resin-based composites (RBCs) and conventional glass-ionomer materials for flexural strength (FS), diametral tensile strength (DTS), and Vickers hardness number (VHN) in the presence of thermocycling.
Materials and methods:Five restorative materials [Tetric N-Ceram Bulk Fill; smart dentin replacement (SDR) Flowable Material; Bioactive restorative material (ACTIVA Bulk Fill); Ketac Universal Aplicap; and GC Fuji II] were evaluated for DTS, FS, and VHN. Half the samples in each material group were thermocycled. The DTS was performed under compressive load at a cross-head speed of 1.0 mm/min. The FS was assessed by three-point bending test at a cross-head speed of 0.5 mm/min. The VHN was determined using a Vickers diamond indenter at 50 gf load for 15 seconds. Differences in FS, DTS, and VHN were analyzed using analysis of variance (ANOVA) and Tukey post hoc tests at α = 0.05 level of significance.Results: N-Ceram, ACTIVA, and SDR demonstrated the highest and comparable (p > 0.05) FS. The SDR had the highest DTS value (141.28 ± 0.94), followed by N-Ceram (136.61 ± 1.56) and ACTIVA (129.05 ± 1.78). Ketac had the highest VHN value before and after thermocycling.
Conclusion:ACTIVA showed mechanical properties (FS and DTS) comparable with bulk-fill resin composite materials. ACTIVA showed potential for durability, as VHN was comparable post-thermocycling.Clinical significance: Bioactive materials showed acceptable DTS and FS values. However, hardness was compromised compared with included materials. ACTIVA Bulk Fill shows potential for dentin replacement but it needs to be covered with a surface-resistant restorative material. Further studies to improve surface characteristics of ACTIVA Bulk Fill are recommended.
“…The authors suggest that substances released by this cement had induced intense inflammatory response in the initial periods and because of this, the tissue had not been able to achieve adequate remodeling even after 30 days of follow-up. The RMO ® contains BisGMA, a monomer with a low degree of conversion values due to the presence of strong hydrogen bond and π -π interactions provided by bisphenol-A (Gajewski et al 2012). Normally, the monomers present in these materials are converted into polymers during the polymerization process, however, inadequate conversion would result in a larger quantity of residual monomers capable of causing a significant cytotoxic effect and affecting the compatibility of the material with the oral tissues (Lacerda-Santos et al 2014, 2016a, Santos et al 2012 compatibility.…”
The focus of this study was to test the hypothesis that there would be no difference between the biocompatibility of resin-modified glass ionomer cements. Sixty male Wistar rats were selected and divided into four groups: Control Group; Crosslink Group; RMO Group and Transbond Group. The materials were inserted into rat subcutaneous tissue. After time intervals of 7, 15 and 30 days morphological analyses were performed. The histological parameters assessed were: inflammatory infiltrate intensity; reaction of multinucleated giant cells; edema; necrosis; granulation reaction; young fibroblasts and collagenization. The results obtained were statistically analyzed by the Kruskal-Wallis and Dunn test (P<0.05). After 7 days, Groups RMO and Transbond showed intense inflammatory infiltrate (P=0.004), only Group RMO presented greater expression of multinucleated giant cell reaction (P=0.003) compared with the control group. After the time intervals of 15 and 30 days, there was evidence of light/moderate inflammatory infiltrate, lower level of multinucleated giant cell reaction and thicker areas of young fibroblasts in all the groups. The hypothesis was rejected. The Crosslink cement provided good tissue response, since it demonstrated a lower level of inflammatory infiltrate and higher degree of collagenization, while RMO demonstrated the lowest level of biocompatibility.
“…The incorporation of TEGDMA monomers to this blend increases the conversion degree due to its high mobility. Also, the higher amount of TEGDMA monomers proportional to Bis-GMA increases the extent and the degree of reticulation of the resulting polymer, reducing its susceptibility to water penetration and solubilization 11,19 . This may explain the lower water sorption and solubility of Natural Glaze when compared to Permaseal, as the former is constituted by Bis-GMA and TEGDMA and most likely formed a denser polymer by the presence of this monomer [16][17] .…”
Surface sealants have been suggested as final glaze of the surface of composite restorations. However, little is known about bulk and surface properties of these materials aiming the long-term preservation of the surface integrity of these restorations. Aim: To evaluate the water sorption, solubility and surface roughness of commercial surface sealants for restorations. Methods: Five disc-shaped specimens (15 mm diameter X 1 mm high) were made from the surface sealants Natural Glaze (DFL) and Permaseal (Ultradent) and were light cured according to the manufacturer's instructions. The specimens were finished with 1500-grit SiC paper. Water sorption (WS) and solubility (SL) were assessed as recommended by the ISO 4049/2000 and were expressed in µg/mm 3 . Surface roughness was evaluated before and after WS and SL, and was expressed in µm as R 1 (before WS and SL) and R 2 (after WS and SL). It was obtained from three parallel measurements along a 4mm length. Data were analyzed using t-test and paired t-test (α=0.05). Results: Water sorption and solubility of Natural Glaze were significantly lower than that of Permaseal (p<0.05). Degradation of the surface sealants did not affect significantly their surface roughness (p>0.05). Conclusions: Surface sealants used in composite restorations undergo hydrolytic degradation; however, this degradation seems not to interfere on surface roughness of these materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.