Development and application of a new testing system of contraction stress of composite materials
10.3760/cma.j.issn.1002-0098.2011.s1.021
- VernacularTitle:复合树脂收缩应力测量系统初探
- Author:
Shuo PAN
1
;
Gang ZHENG
;
Hong LIN
;
Bo-Tao GAO
;
Wei BAI
Author Information
1. 北京大学口腔医学院(口腔医院)
- Keywords:
Composite resin;
Polymerization;
Contraction stress
- From:
Chinese Journal of Stomatology
2011;46(z1):89-93
- CountryChina
- Language:Chinese
-
Abstract:
Objective The aim of this study was to compare the contraction stress of a new low-shrinkage silorane-based composite (P 90 ) and a new low-shrinkage nanohybrid composite (Venus Diamond) with two conventional dimethacrylate-based composites using new measuring systems.Methods The materials tested were P 90 (3M ESPE),Venus Diamond (Heraeus),Z 350 (3M ESPE),and Charisma Opal(Heraeus).Shrinkage stress was assessed using a stress-strain analyzer consisting of two opposing attachments,one connected to a load cell and the other fixed to the device.All specimens were light-cured and the contraction stress (MPa) generated during polymerization was continuously recorded for 300 s.The contraction stress after 30,60,300 s were recorded.Results The silorane-based composite (P 90) and new low-shrinkage nanohybrid composite (Venus Diamond ) exhibited significantly lower contraction stress and very slowly cure rate than the conventional dimethacrylate-based composites.Contraction stresses after 300 s were:Z 350[ (4.08 ±0.12) MPa] ＞ Charisma Opal[ ( 1.92 ±0.10) MPa]＞ Venus Diamond [ ( 1.16 ± 0.03 ) MPa] ＞ P 90 [ ( 0.94 ± 0.04 ) MPa],and significant differences among groups were observed ( P ＜ 0.05).Conclusions A new test system can continuously record the contraction stress during polymerization.The low-shrinkage composites ( P 90 and Venus Diamond) tested in the study show an improvement in terms of reducing contraction stress and reducing cure rate.Some new monomer comoositions of the resin matrix can be valid alternatives to dimethacrylates.
