Table of Contents Author Guidelines Submit a Manuscript
International Journal of Dentistry
Volume 2009, Article ID 781462, 7 pages
http://dx.doi.org/10.1155/2009/781462
Clinical Study

Clinical Performance of Viscous Glass Ionomer Cement in Posterior Cavities over Two Years

1Department of Operative Dentistry and Endodontics, Medical Center for Dentistry, University Medical Center Giessen and Marburg, Georg-Voigt-Street 3, 35039 Marburg, Germany
2College of Dentistry, University of Tennessee, 875 Union Avenue, Memphis, TN 38163, USA
3The Forsyth Institute, 140 Fenway, Boston, MA 02115, USA
4Department of Pediatric Dentistry, Medical Center for Dentistry, University Medical Center Giessen and Marburg, Schlangenzahl 14, 35392 Giessen, Germany

Received 22 July 2009; Accepted 7 December 2009

Academic Editor: Toru Nikaido

Copyright © 2009 Roland Frankenberger et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In this controlled prospective clinical study the highly viscous glass ionomer cement Ketac Molar was clinically assessed in Class I and Class II cavities. Forty-nine subjects (mean age 32.3 years) received 108 restorations placed by six operators in conventional Black I and II type cavities with undercuts after excavating primary lesions or after removing insufficient restorations. At baseline, and after 6, 12, and 24 months, restorations were assessed by two independent investigators according to modified USPHS codes and criteria. Impressions of the restorations were taken and epoxy replicas were made. Between the baseline and the 24-month recall, 51 representative samples were analyzed at 130 × magnification by use of a stereo light microscope (SLM). Recall rates were 83% after 6 months, 50% after 12 months, and 24% after 24 months. Failure rates after 24 months were 8% for Class I and 40% for Class II fillings, mainly due to bulk fracture at occlusally loaded areas (Kaplan Meier survival analysis). Significant changes over time were found for the criteria “surface roughness”, “marginal integrity”, “restoration integrity”, and “overall judgement” (P<.05; Friedman test). SLM analysis revealed statistically significant differences for the following criteria over time (baseline/6 months/12 months (in % of entire evaluable margin length); P<.05; Friedman 2-way ANOVA): perfect margin 37/19/11, negative step formation 26/49/57, gap formation 2/7/9, and overhang 24/11/8. Replicas exhibited mainly negative step formation as main finding due to apparently inferior wear resistance (P<.05). Gap formations were more frequently observed in Class II restorations than in Class I (12% versus 3% after 12 months; P<.05, Mann-Whitney-U test). The evaluated margin lengths were not statistically different (P>.05, Friedman 2-way ANOVA).