hrvatski

Testiranje savojne čvrstoće i modula elastičnosti bulk-fill kompozitnih materijala: metodološka analiza

INTRODUCTION: Scientific research often compares the final values of the mechanical properties of individual materials without considering the preparation of specimens in various moulds. Thus, in this study, the emphasis was on comparing two methodologies: the use of silicone and Teflon moulds. The research aimed to compare the results of flexural strength and modulus of identical materials made in different moulds. MATERIALS AND METHODS: Five bulk-fill composite materials were tested, including three high-viscosity materials (Tetric PowerFill, Ivoclar Vivadent ; Filtek One Bulk Fill Restorative, 3M ; QuiXfil Posterior Restorative, Dentsply Sirona) and two low- viscosity (Tetric PowerFlow, Ivoclar Vivadent ; SDR Plus Bulk Fill Flowable, Dentsply Caulk). Specimens (n = 10) were made in an orange silicone mould or a white Teflon mould. Two types of polymerisations were used: (I) according to ISO 4049 (2x2x16 mm, polymerised with Bluephase® PowerCure (Ivoclar Vivadent) 6x20 on both sides, average intensity 1079 mW/cm2) or (II) 3s protocol (2x4x16 mm polymerised 3x3 s, unilaterally, with an average intensity of 2602 mW/cm2). The specimens were stored in distilled water at 37ºC for 24 h and subjected to a three-point bending test. The results were analysed by Wilcoxon Matched Pairs Test (p <0.05). RESULTS: All materials showed significantly higher flexural strength and modulus in 3s polymerisation compared to ISO polymerisation, regardless of the mould type. The flexural modulus of specimens polymerised with the 3s-protocol in Teflon moulds was statistically higher than in silicone moulds. There was no difference in the flexural modulus of the samples polymerised by the ISO protocol. The flexural strength values of QuiXfil and Tetric PowerFill polymerised by the ISO protocol were significantly higher in silicone moulds than in Teflon. There was no significant difference in the same type of polymerisation in others. In contrast, in samples polymerised with the 3s- protocol, a significant statistical difference was observed only in Filtek, SDR and PowerFlow. CONCLUSION: The type of mould significantly affects the flexural modulus in 3s polymerisation of 4 mm thick samples, with samples made in Teflon moulds having a higher flexural modulus. The influence of the mould type on the flexural strength depended on the kind of material. The mechanical properties of the tested bulk-fill composites were influenced more by the polymerisation method than by the mould type. This research was funded by the Croatian Science Foundation, project IP-2019-04-6183.

savojna čvrstoća ; modul elastičnosti ; kalup ; debeloslojni kompoziti

nije evidentirano

engleski

Testing of flexural strength and modulus of bulk- fill composite materials: methodological analysis

INTRODUCTION: Scientific research often compares the final values of the mechanical properties of individual materials without considering the preparation of specimens in various moulds. Thus, in this study, the emphasis was on comparing two methodologies: the use of silicone and Teflon moulds. The research aimed to compare the results of flexural strength and modulus of identical materials made in different moulds. MATERIALS AND METHODS: Five bulk-fill composite materials were tested, including three high-viscosity materials (Tetric PowerFill, Ivoclar Vivadent ; Filtek One Bulk Fill Restorative, 3M ; QuiXfil Posterior Restorative, Dentsply Sirona) and two low- viscosity (Tetric PowerFlow, Ivoclar Vivadent ; SDR Plus Bulk Fill Flowable, Dentsply Caulk). Specimens (n = 10) were made in an orange silicone mould or a white Teflon mould. Two types of polymerisations were used: (I) according to ISO 4049 (2x2x16 mm, polymerised with Bluephase® PowerCure (Ivoclar Vivadent) 6x20 on both sides, average intensity 1079 mW/cm2) or (II) 3s protocol (2x4x16 mm polymerised 3x3 s, unilaterally, with an average intensity of 2602 mW/cm2). The specimens were stored in distilled water at 37ºC for 24 h and subjected to a three-point bending test. The results were analysed by Wilcoxon Matched Pairs Test (p <0.05). RESULTS: All materials showed significantly higher flexural strength and modulus in 3s polymerisation compared to ISO polymerisation, regardless of the mould type. The flexural modulus of specimens polymerised with the 3s-protocol in Teflon moulds was statistically higher than in silicone moulds. There was no difference in the flexural modulus of the samples polymerised by the ISO protocol. The flexural strength values of QuiXfil and Tetric PowerFill polymerised by the ISO protocol were significantly higher in silicone moulds than in Teflon. There was no significant difference in the same type of polymerisation in others. In contrast, in samples polymerised with the 3s- protocol, a significant statistical difference was observed only in Filtek, SDR and PowerFlow. CONCLUSION: The type of mould significantly affects the flexural modulus in 3s polymerisation of 4 mm thick samples, with samples made in Teflon moulds having a higher flexural modulus. The influence of the mould type on the flexural strength depended on the kind of material. The mechanical properties of the tested bulk-fill composites were influenced more by the polymerisation method than by the mould type. This research was funded by the Croatian Science Foundation, project IP-2019-04-6183.

flexural strength ; flexural modulus ; bulk-fill composites

nije evidentirano