In Vitro Biocompatibility of Preheated Giomer and MicrofilledHybrid Composite

Abstract

ObjectiveThe aim of this study was to evaluate cytotoxic potencies of two light cured composite materials after heating on different temperatures and cured directly and through CAD/CAM overlay.Materials and methodsComposite materials (microfilled-hybrid Gradia Direct Posterior and Beautifil II) were heated in a Calset warming unit at three different temperatures (T1:37°C, T2:54°C, T3:68°C). A small amount of heated composite material was placed in a round mold (diameter 6mm; 0.65mm thick), covered with Mylar sheet, pressed and polymerized with Bluephase LED unit. One group of samples were polymerized directly, and the other group through 2mm thick CAD/CAM ceramic-reinforced polymer (CRP) and CAD/CAM lithium disilicate ceramic (LDC) overlay for 20 and 40 seconds. The polymerized samples were placed immediately after curing in a lymphocyte cell culture. The viability of peripheral blood lymphocytes was evaluated using a dye exclusion technique by simultaneous staining with ethidium bromide and acridine orange. Quantitative assessments were made by determination of the percentage of viable, apoptotic and necrotic cells. The Pearson chi-square test was used for statistical analysis.ResultsIn case of 20 seconds polymerization, the highest number of viable cells polymerization were recorded when materials were heated at 37°C (T1), while in case of 40 seconds polymerization, the highest number of viable cells were recorded when the materials were heated at 54°C (T2). The samples polymerized through CAD/CAM overlays showed less cytotoxicity than samples polymerized directly.ConclusionApart from composite material composition, the cell viability was also influenced by curing time, temperature of pre-heating and polymerization pattern.

Effect of preheating on the cytotoxicity of bulk-fill composite resins

“…This result was consistent with those of a study by Deb et al 11 In their reports, the pre-heating of composite resins did not significantly influence their cytotoxicity. However, the study by Knežević et al 13 suggested that cell viability was affected by the pre-heating temperature. In their study, the highest cell viability was reported in composite resins pre-heated up to 54°C with 40 seconds of curing time and at 37°C with 20 seconds of curing time.…”

“…12 It seems that a reduction in unreacted monomers can affect the cytotoxic properties of composite resins. Knežević et al 13 found that, regardless of the chemical composition of the composite resin material, the number of living cells is affected by the pre-heating temperature. 13 On the other hand, in another study, the effect of pre-heating on the cytotoxicity of conventional composite resin materials was not significant.…”

“…Knežević et al 13 found that, regardless of the chemical composition of the composite resin material, the number of living cells is affected by the pre-heating temperature. 13 On the other hand, in another study, the effect of pre-heating on the cytotoxicity of conventional composite resin materials was not significant. 11 During the placement of light-activated conventional composite resins, it is recommended to use increments with a thickness of <2 mm (the incremental technique).…”

“…12 Several studies have investigated the cytotoxicity of bulk-fill composite resins. [9][10][11][12][13][14][15][16][17] Toh et al 18 investigated the biocompatibility of bulk-fill composite resins with and without pre-polymerized filler in vitro. In their study, some bulk-fill composite resins with a thickness of 4 mm showed a cell viability of <70%.…”

Uso de resina pré-aquecida como material cimentante em restauração indireta: Uma revisão de literatura

“…Assim, a termoplastificação desses compósitos não causa reações adversas, e sua citocompatibilidade dos componentes liberados não foram afetadas. Em contrapartida, Knežević et al (2018) relataram que a viabilidade celular foi afetada pela temperatura de pré-aquecimento. Neste estudo foram utilizados linfócitos para investigar viabilidade celular por contato direto com resina composta amostras, a maior viabilidade celular foi relatada em resinas compostas pré-aquecidas até 54 °C com 40 segundos do tempo de fotopolimerização e a 37 ° C com 20 segundos de fotopolimerização.…”