Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

Brazilian Dental Journal

Fernando Henrique Ruppel Osternack²  Danilo Biazzetto De Menezes Caldas²  Rodrigo Nunes Rached²  Sérgio Vieira²  Jeffrey A. Platt¹  Janaina Bertoncelo De Almeida² 

[1] ,Pontifical Catholic University of Paraná Department of Restorative Dentistry Curitiba PR ,Brazil

关键词: resin composite;    refrigeration;    Knoop hardness;   

DOI  :  10.1590/S0103-64402009000100007

来源: SciELO

【 摘 要 】

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

【 授权许可】

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