Effect of early water exposure on the strength of glass ionomer restoratives

Wang, X. Y., Yap, A. U. J. and Ngo, H. C. (2006) Effect of early water exposure on the strength of glass ionomer restoratives. Operative Dentistry, 31 5: 584-589. doi:10.2341/05-106

Author Wang, X. Y.
Yap, A. U. J.
Ngo, H. C.
Title Effect of early water exposure on the strength of glass ionomer restoratives
Journal name Operative Dentistry   Check publisher's open access policy
ISSN 0361-7734
Publication date 2006-09
Sub-type Article (original research)
DOI 10.2341/05-106
Volume 31
Issue 5
Start page 584
End page 589
Total pages 6
Place of publication Indianapolis, IN, United States
Publisher Operative Dentistry
Language eng
Abstract This study examined the effect of early water exposure on the shear strength of a spectrum of glass ionomer restoratives. The materials evaluated included conventional auto-cured (Fuji II [FT], GC), resin-modified light-cured (Fuji II LC [FL]) and, recently introduced, high strength auto-cured (Fuji IX GP Fast [FN], GC; Ketac Molar Quick [KQ], 3M-ESPE; Ketac Molar [KM], 3M-ESPE) cements. Sixteen specimens (8.7-mm in diameter and 1-mm thick) of each material were prepared in metal washers and randomly divided into 2 groups. The specimens were allowed to set for 6 minutes between polyester strips, to ensure completion of the initial set. The strips were subsequently removed, and the surfaces of Group 1 specimens were coated on both sides with resin (Fuji Coat LC, GC) and light cured for 10 seconds. Group 2 specimens were left uncoated. All specimens were then conditioned in distilled water at 37°C for 4 weeks. After conditioning, the specimens were restrained with a torque of 2.5 Nm and subjected to shear punch testing using a 2-mm diameter punch at a crosshead speed of 0.5-mm/minute. The mean shear strengths of the materials were computed and subjected to Independent Samples t-test and ANOVA/Scheffe's tests at significance level 0.05. Mean strength ranged from 78.34 to 99.36 MPa and 79.88 to 95.78 MPa for Groups 1 and 2, respectively. No significant difference in shear strength was observed between the 2 groups. For both groups, KM and KQ were significantly stronger than FT. Contrary to current teaching, early exposure to water did not weaken glass ionomer restoratives. A marginal increase in strength was actually observed for some materials.
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Dentistry Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 6 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 17 Nov 2010, 14:18:05 EST