ABSTRACT: 0340

Diametral Tensile Strength Using Composite Cores with Nonmetallic Prefabricated Posts

B.E. RAUSCH, and K. VANDEWALLE, USAF, Lackland AFB, TX, USA

Objectives: The purpose of this study was to determine the diametral tensile strength (DTS) of a resin-composite core (Clearfil Photo Core, Kuraray) bonded to three nonmetallic prefabricated posts with and without silanation. Systems included quartz-fiber (DT Light Post, Bisco), glass-fiber (FibreKleer, Jeneric/Pentron), and ceramic (CeraPost, Brasseler) posts with similar diameters and shape. Methods: Ten samples were prepared per group (n=10). Another group was prepared as a control using composite resin only. A 3x6mm aluminum mold was placed on a glass slide and core material was inserted. The surface of the posts to be silanated was treated with Clearfil Silane (Kuraray). Bonding agent (Clearfil Photobond, Kuraray) was applied to the coronal portion of all posts and light polymerized for 20 seconds (Bluephase 16i, Ivoclar). The posts were inserted in the center of the filled mold, pressed down to the slide, and excess material was removed. The samples were cured again for 20 seconds at the post insertion and glass slide levels. Following separation, the samples were cured for 20 seconds on both sides. Samples were stored in 37^oC distilled water for 24 hours before compressive loading in a universal testing machine (Model 5543, Instron) at 0.5 mm/min crosshead speed. A mean (MPa) and standard deviation were determined per group. Results: A difference was found between groups using a one-way ANOVA (p<0.001). The control group was significantly stronger than all other groups. See Table. A 2-way ANOVA was performed (excluding control) to examine the effects of post type or surface treatment on DTS. A difference was found based on post type (p=0.008) but not surface treatment (p=0.22). However, there was a significant interaction (p=0.02). Conclusion: The use of all three types of posts reduced the DTS compared with the solid composite (control).

^{Post Type/Surface Treatment}

^MPa^{(st dev)}

^{Control (solid composite)}

^{58.4 (2.3) a}

^{DT Light Post – silanated}

^{42.7 (2.1) b}

^FibreKleer^{– unsilanated}

^{42.3 (2.7) b}

^{DT Light Post – unsilanated}

^{40.7 (4.3) bc}

^CeraPost^{– unsilanated}

^{39.7 (2.6) bc}

^FibreKleer^{– silanated}

^{39.2 (3.2) bc}

^CeraPost^{– silanated}

^{38.0 (1.6) c}

^{Groups with the same letter are not significantly different (p>0.05)}

Seq #60 - Core Materials, Electrosurgery, Lasers, Burs, Ultrasonic Preparation
2:45 PM-3:45 PM, Thursday, April 3, 2008
Hilton Anatole Hotel Trinity I - Exhibit Hall

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