Effect of the applied load on surface contact fatigue of dental filling materials.

Abstract

OBJECTIVE:

The purpose of this study was to investigate the effect of the applied load in a rolling-ball device on the surface contact fatigue of two dental filling materials: a microfilled composite (FA) and a glass ionomer (GFII).

METHODS:

Disk specimens 10 mm diameter by 1.5 mm thick were set into cavities cut in plates of PMMA. After setting, the specimens were ground and polished using wet-carborundum paper followed by 1 microm alumina and then stored for 24 h in water at 23 degrees C. The surface fatigue test was carried out using loads ranging from 100 to 500 gf through a ruby ball 2 mm diameter using a rolling-ball device. The ball was set to rotate at 720 rpm and a surface profile was determined on impressions recorded at regular intervals. Fatigue life was defined as the number of cycles to produce a track 5 microm deep and was determined by interpolation. Data were statistically analyzed by ANOVA and t-tests at a significance level of 0.05.

RESULTS:

At loads ranging from 200 to 500 gf the fatigue life was 0.7-10.6 x 10(5) cycles for FA, and 0.7-4.8 x 10(3) cycles for GFII. For both materials the fatigue life was reduced significantly by increasing the test load (p<0.05). The surface contact fatigue life for FA was at least 100 times greater than that for GFII at all loads.

SIGNIFICANCE:

The rolling ball device was confirmed as a simple and meaningful device for the study of surface contact fatigue. A microfilled composite is very much more resistant to contact fatigue than a glass ionomer.

• Authors: Koichi Fujii, Thomas E Carrick, Robert Bicker, John F McCabe
• Journal: Dental materials : official publication of the Academy of Dental Materials (Dent Mater) Vol. 20 Issue 10 Pg. 931-8 (Dec 2004) ISSN: 0109-5641 [Print] England
• PMID: 15501321 (Publication Type: Journal Article, Validation Study)

Chemical References

• Composite Resins
• Filtek A110 composite resin
• Glass Ionomer Cements
• Fuji glass-ionomer lining cement

Topics

• Composite Resins
• Dental Restoration Wear
• Dental Restoration, Permanent
• Dental Stress Analysis (instrumentation)
• Friction
• Glass Ionomer Cements
• Materials Testing
• Surface Properties