Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems

Objectives: This study aimed to assess the bi-axial flexural strength of two dual-polymerizing resin luting agents cemented to human dentin when photo-activated with different light-curing units. Materials and methods: Two dual-cured resin cements: choice (CH) and Variolink II (VL) were tested. Hybr...

Full description

Saved in:
Bibliographic Details
Main Author: Nadia Malek A. Taher
Format: Article
Language:English
Published: Springer 2010-07-01
Series:Saudi Dental Journal
Online Access:http://www.sciencedirect.com/science/article/pii/S1013905210000404
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850189054863212544
author Nadia Malek A. Taher
author_facet Nadia Malek A. Taher
author_sort Nadia Malek A. Taher
collection DOAJ
description Objectives: This study aimed to assess the bi-axial flexural strength of two dual-polymerizing resin luting agents cemented to human dentin when photo-activated with different light-curing units. Materials and methods: Two dual-cured resin cements: choice (CH) and Variolink II (VL) were tested. Hybrid composite resin (Z-250) discs (12 × 1.5 mm) were fabricated. Three types of light-curing units were used halogen-curing unit (QTH), light-emitting diode (LED) and plasma arc (PAC). Sixty dentin discs of 0.5 mm thickness were prepared from extracted human teeth. A circular mold (2.5 mm in height and 12 mm diameter) was utilized to create supporting structure for dentin, resin cement complex. The resin luting cement (0.5 mm) was placed on the previously prepared dentin discs and covered with the prefabricated composite discs. Photo-activation of cements was performed for 40 s with QTH and LED units and for 3 s with PAC. The specimens were divided into 12 groups (20 specimens for each light source). Six groups were kept in distilled water for 24 h and the rest were stored for 6 weeks. Bi-axial flexural strength was determined using Instron machine. The data was analyzed using two-way ANOVA and Tukey test for comparison. Results: The findings indicated that the bi-axial flexural strength values for both cements CH and VL were higher for 24 h over 6 weeks but not statistically significant when cured with QTH. Meanwhile, when LED light was used for photo-activation the cements, the flexural strength values reported were statistically higher of 24 h over 6 weeks storage at P = 0.4E−6 However, PAC light did not record any statistically significant difference between two duration for the CH cement although when used for polymerization of VL the reported value for 6 weeks were statistically significantly higher value than 24 h duration at P = 0.002. Conclusion: When high immediate flexural strength is preferred in clinical situation photo-activation the cements with LED reported the greatest value. Keywords: Bi-axial flexural strength, Light-curing unit, Resin cement, Dual curing cement
format Article
id doaj-art-55e00657dbfd4f78a7e6ddc56cbb36da
institution OA Journals
issn 1013-9052
language English
publishDate 2010-07-01
publisher Springer
record_format Article
series Saudi Dental Journal
spelling doaj-art-55e00657dbfd4f78a7e6ddc56cbb36da2025-08-20T02:15:42ZengSpringerSaudi Dental Journal1013-90522010-07-0122310711210.1016/j.sdentj.2010.04.002Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systemsNadia Malek A. Taher0Division of Operative Dentistry, Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 5967, Riyadh 11432, Saudi ArabiaObjectives: This study aimed to assess the bi-axial flexural strength of two dual-polymerizing resin luting agents cemented to human dentin when photo-activated with different light-curing units. Materials and methods: Two dual-cured resin cements: choice (CH) and Variolink II (VL) were tested. Hybrid composite resin (Z-250) discs (12 × 1.5 mm) were fabricated. Three types of light-curing units were used halogen-curing unit (QTH), light-emitting diode (LED) and plasma arc (PAC). Sixty dentin discs of 0.5 mm thickness were prepared from extracted human teeth. A circular mold (2.5 mm in height and 12 mm diameter) was utilized to create supporting structure for dentin, resin cement complex. The resin luting cement (0.5 mm) was placed on the previously prepared dentin discs and covered with the prefabricated composite discs. Photo-activation of cements was performed for 40 s with QTH and LED units and for 3 s with PAC. The specimens were divided into 12 groups (20 specimens for each light source). Six groups were kept in distilled water for 24 h and the rest were stored for 6 weeks. Bi-axial flexural strength was determined using Instron machine. The data was analyzed using two-way ANOVA and Tukey test for comparison. Results: The findings indicated that the bi-axial flexural strength values for both cements CH and VL were higher for 24 h over 6 weeks but not statistically significant when cured with QTH. Meanwhile, when LED light was used for photo-activation the cements, the flexural strength values reported were statistically higher of 24 h over 6 weeks storage at P = 0.4E−6 However, PAC light did not record any statistically significant difference between two duration for the CH cement although when used for polymerization of VL the reported value for 6 weeks were statistically significantly higher value than 24 h duration at P = 0.002. Conclusion: When high immediate flexural strength is preferred in clinical situation photo-activation the cements with LED reported the greatest value. Keywords: Bi-axial flexural strength, Light-curing unit, Resin cement, Dual curing cementhttp://www.sciencedirect.com/science/article/pii/S1013905210000404
spellingShingle Nadia Malek A. Taher
Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
Saudi Dental Journal
title Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
title_full Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
title_fullStr Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
title_full_unstemmed Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
title_short Bi-axial flexural strength of dual-polymerizing agents cemented to human dentin after photo-activation with different light-curing systems
title_sort bi axial flexural strength of dual polymerizing agents cemented to human dentin after photo activation with different light curing systems
url http://www.sciencedirect.com/science/article/pii/S1013905210000404
work_keys_str_mv AT nadiamalekataher biaxialflexuralstrengthofdualpolymerizingagentscementedtohumandentinafterphotoactivationwithdifferentlightcuringsystems