Analysis of surface hardness of artificially aged resin composites

Tornavoi, Denise Cremonezzi; Satoa, Sandra; Silva, Leandro Jardel; Agnelli, José Augusto Marcondes; Reis, Andréa Cândido dos

doi:10.1590/s1516-14392012005000001

“…The degree of cross-linking and conversion can also have a positive effect on microhardness as well as the content of zirconium particles in the Z550 structure. The research presented in [50,51] showed that as the content of zirconium particles in the material increases, the hardness of the composite increases. The hardness of zirconium particles is 17 GPa, while another popular filler, also used in experimental materials, is about 3–4 GPa [45].…”

Section: Resultsmentioning

confidence: 99%

The Effect of Thermocycling on Surface Layer Properties of Light Cured Polymer Matrix Ceramic Composites (PMCCs) Used in Sliding Friction Pair

Pieniak

¹

,

Walczak

²

,

Niewczas

³

et al. 2019

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This paper discusses the problem of thermocycling effect of light-curing polymer–ceramic composites. Cyclic thermal shocks were simulated in laboratory conditions. As a rule, these loads were supposed to reproduce the actual conditions of biomaterials exploitation. Periodically variable stresses occurring in dental restorations are associated with the wear of cold and hot foods and beverages. They lead to changes in the properties of composites, including the properties of the surface layer. The aim of the work was to assess the impact of cyclic hydrothermal interactions on the properties of the surface layer of composites relevant to the operational quality. Two commercial materials manufactured by the world’s leading producer (3M ESPE)—Filtek Z550, Filtek Flow and two experimental, micro-hybrid and flow type composites marked Ex-mhyb(P) and Ex-flow(P), respectively. All tests were carried out before and after hydro-thermal cycles (flowing water thermocycling). Micro-hardness test using the Vickers method, indentation hardness, and resistance to tribological wear in a ball–disc system in sliding friction conditions were performed. In addition, observations of the surface layer of composites on the SEM (scanning electron microscope) were carried out. It was noticed that semi-liquid composites, containing a smaller amount of filler, retain higher stability of mechanical and tribological properties of the surface layer under cyclic hydro-thermal loads. Coefficient of friction of samples after hydro-thermal cycles increased for micro-hybrid materials and Filtek Flow (FFlow) composite. In the case of Ex-flow(P) material, the coefficient of friction decreased. The microhardness of composites also changed, the variability of this size depended on the type of material. Composites with a higher content of filler particles were characterized by greater variability of microhardness under the influence of thermocycles. The resistance to tribological wear also changed in a similar way. Composites containing higher volume fraction of inorganic filler showed higher tribological wear after thermocycling. The wear resistance of flow composites changed to a lesser extent, after thermocycling increased. The paper also showed that, in real kinematic nodes, the surface layer of light-curing ceramic–polymer composites is exposed to significant non-tribological (erosive, thermal, and chemical) defects that synergize with tribological ones. In slip pairs loaded dynamically, under mixed friction conditions, tribological wear of PMCCs (polymer matrix ceramic composites) is manifested by spalling (spalling of the material flakes, in particular the polymer phase) and pitting (crushing wear caused by wear products, in particular large filler particles or clusters, previously adhesively extracted).

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“…In our study, zirconia particles may have affected the increase in the hardness values of Filtek Z250. A previous study [ 14 ] found that among different resin composites, the composite material (Z250-microhybrid) with silica and zirconia content was the hardest. Another study showed that the mechanical properties of the prepolymerized structure contained in Charisma Smart might be weak [ 36 ].…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, Rattacaso et al [ 42 ] demonstrated an increase (after AAA) in the Knoop microhardness values of the resin composite materials evaluated in their study. Another study found that AAA did not affect the hardness values of resin composites, but there were significant differences in hardness values between materials [ 14 ]. In our study, the hardness values of the investigated resin composites significantly increased after AAA, as postpolymerization was caused by an increase in temperature and water condensation [ 42 ].…”

Section: Discussionmentioning

confidence: 99%

“…The aging method can cause changes in the microstructure of materials, the compositions of matrices, and the filler particles of resin composites [ 13 ]. Moreover, AAA can degrade resin matrices by promoting the degradation of resin composites and changing the structural distribution of the particles, negatively affecting the materials' mechanical properties [ 14 ]. AAA can alter optical and mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

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Accelerated Aging Effects on Color Change, Translucency Parameter, and Surface Hardness of Resin Composites

Fidan

¹

2022

BioMed Research International

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Background. The aging process can induce a change in the surface microstructure of materials, the chemical compositions of matrices, and the filler particles of resin composites. This study is aimed at evaluating the effects of accelerated artificial aging (AAA) on the color change, translucency parameter (TP), and surface hardness of resin composites. Methods. Five resin composite materials (Tetric N-Ceram, Filtek Z250, Charisma Smart, Herculite Classic, and Escom100) were evaluated. A spectrophotometer was used for color measurements ( L ∗ , a ∗ , and b ∗ ). TP and color changes ( Δ E 00 ) were calculated using the CIEDE2000 formula. The resin materials were subjected to aging for 300 hours. The hardness and TP values were measured before and after AAA. One- and two-way ANOVA and the Tukey test were used. The significance level was accepted as p < 0.05 . Results. Escom100 had significantly higher Δ E 00 values than the other resin composites, and Charisma Smart had significantly lower Δ E 00 values than the other tested materials ( p < 0.05 ). Before and after AAA, Charisma Smart had the lowest TP values, and Filtek Z250 exhibited the highest hardness values ( p < 0.05 ). For TP and surface hardness, the effect size value of the composite material was found to be higher than that of AAA. Conclusions. After AAA, the investigated resin composites had Δ E 00 values that were above clinically acceptable thresholds. After aging, the tested materials generally exhibited decreases in L ∗ values and a ∗ values, while increases in b ∗ values were observed. The ΔTP values of the resin composites were similar. AAA significantly increased the surface hardness of the tested materials.

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“…The VHN average values of the Universal Restorative 200 composite resin group selected as the control group were found to be higher than the bulk-fill composite resin groups. Tornavoi et al (17) reported that the hardness values of composite resin (Z250-microhybrid) with silica and zirconia content were better among different composite resins. In the materials used in our study, we thought that the Filtek (3M-ESPE) group has higher VHN values compared to the other materials examined, having silica and zirconia content.…”

Section: Discussionmentioning

confidence: 99%

Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins

Fidan

¹

,

Gönder

²

2021

Int Dent Res

1

0

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Aim: The aim of this study was to investigate the effect of different application techniques on microhardness in one universal resin material and three different bulk-fill composite resin materials. Materials and Methods: In this study, one universal composite resin (Universal Restorative 200 [U], 3M-ESPE, USA) and three different bulk-fill composite resins (Filtek-One Bulk-Fill Restorative [F]; 3M-ESPE, USA: Tetric Evo-Ceram Bulk-Fill [E]; and Ivoclar-Vivadent, Liechtenstein; Tetric N-Ceram Bulk-Fill [N], Ivoclar-Vivadent, Liechtenstein) materials were used. A total of 60 disk-shaped samples, including 20 samples from each bulk-fill composite resin group, were prepared. The polymerization of the bulk-fill composite resins in one group was completed using a 2 mm (40 sec) + 2 mm (40 sec) incremental technique, and in the other group, it was completed using a 4 mm bulk technique (40 sec). The U composite resin (control group) polymerization was completed using a 2 mm + 2 mm (40 sec) incremental technique (n = 10). The Vickers microhardness (VHN) values of the samples were calculated. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (p < 0.05). Results: Higher VHN values were found in the U composite resin compared to those in the bulk-fill composite resins (p < 0.05). In the bulk technique, a lower VHN value was observed in the N bulk-fill composite resin than in the control group (p < 0.05), while there was no difference between the N and E composite resin groups (p > 0.05). A lower N bulk-fill composite resin was observed in the groups in which the incremental technique was applied than in the control group (p < 0.05). When the techniques applied to the bulk-fill composite resins were evaluated within themselves, higher VHN values were observed in the E composite resin in the group in which the incremental technique was applied but not in the group in which the bulk was applied. Conclusion: It was observed that the content differences of composite resins were effective at different VHN values. The U composite resin (control) group showed higher VHN values than all the bulk-fill composite groups. How to cite this article: Fidan M, Gönder HY. Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins. Int Dent Res 2021;11(Suppl.1):32-7. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.6 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

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Analysis of surface hardness of artificially aged resin composites

Cited by 12 publications

References 23 publications

The Effect of Thermocycling on Surface Layer Properties of Light Cured Polymer Matrix Ceramic Composites (PMCCs) Used in Sliding Friction Pair

The Effect of Thermocycling on Surface Layer Properties of Light Cured Polymer Matrix Ceramic Composites (PMCCs) Used in Sliding Friction Pair

Accelerated Aging Effects on Color Change, Translucency Parameter, and Surface Hardness of Resin Composites

Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins

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