Preparation time and surface roughness of core foundation resins and dentin.

Statement Of Problem: It is unclear if the preparation of core foundation resins is similar to that of dentin.

Purpose: The purpose of this in vitro study was to compare the preparation time and resulting roughness of 5 core foundation resins and dentin.

Material And Methods: Standardized preparations (10 mm length, 5 mm height) were made of 5 specimens of 5 core materials with a device-mounted dental handpiece (150 000 rpm, water-cooling) with weight-controlled contact pressure (50 g).

Wear and hardness of different core build-up materials.

Before crown preparation, teeth with extensive coronal destructions are built up with core materials. Sometimes, these build ups are exposed to the oral environment without the protection of crowns. Therefore, this in vitro investigation was aimed at evaluating the wear, surface roughness, Vickers hardness, and surface structure of 10 core composites, two glass ionomer cements (GICs), and four posterior restoration composites.