INVESTIGATION OF FRACTURE RESISTANCE OF DIFFERENT CORE MATERIALS

The aim of this study was comparatively investigation of in vitro fracture resistance of four different restorative core materials in endodontically-treated mandibulary premolar teeth. Eighty caries-free human permanent mandibular premolar teeth, freshly extracted because of periodontal or orthodontic reasons were randomly divided into four groups of 20 teeth each. Core restorations were prepared using these core materials: Group 1: Filtek P60 (3M ESPE, USA), Group 2: Clearfil Photo Core (Kuraray Medical Inc., Japan), Group 3: Miracle Mix (GC Corporation, Japan) and Group 4: Vitremer (3M ESPE, USA). Then were subjected to thermocycling 1.000 times with a dwell time of 30 second at 5 ± 2 oC and 55 ± 2 oC. The teeth were loaded in a Universal Testing Machine (TSTM 02500; Elista Ltd. Şti., Turkiye). All the teeth were loaded until fracture was occured. The fracture force (Newton) was recorded for each specimen. The results obtained were statistically evaluated with ANOVA and Bonferroni corrected Mann Whitney U-tests. Statistically, the mean fracture resistance scores among groups (p<0.001) and values of fracture code between Group 1 and Group 4, were significant. The group of Filtek P60 was found succesfull when the values of fracture resistance were examined. Experimental article (J Int Dent Med Res 2012; 5: (2), pp. 85-90)