Effect of Nd:YAG laser parameters on the penetration depth of a representative Ni-Cr dental casting alloy.

The effects of voltage and laser beam (spot) diameter on the penetration depth during laser beam welding in a representative nickel-chromium (Ni-Cr) dental alloy were the subject of this study. The cast alloy specimens were butted against each other and laser welded at their interface using various voltages (160-390 V) and spot diameters (0.2-1.

Biotribological behavior of two retrieved implant abutment screws after long-term use in vivo.

Purpose: To evaluate the effect of functional cyclic loading on two retrieved abutment screws used with single implant supporting cement-retained porcelain-fused-to-metal crowns by characterizing the structure, properties, and biotribologic behavior after long-term use in vivo.

Materials And Methods: Two abutment screws were retrieved from the same patient and same implant at two different times. An external hex implant was used to replace a missing central incisor.

The effect of repeated torque and salivary contamination on the preload of slotted gold implant prosthetic screws.

Statement Of Problem: Screw loosening and/or fracture is common and has been attributed to many factors, including improper torque and preload. Purpose. This study evaluated the effect of repeated preload torque and salivary contamination on the preload of the slotted gold implant prosthetic screw.

The effect of repeated torque on the ultimate tensile strength of slotted gold prosthetic screws.

Statement Of Problem: Repeated torque may alter the mechanical properties and fracture resistance of certain prosthetic retaining screws.

Purpose: This study evaluated the effect of repeated torque and salivary contamination on the ultimate tensile strength of one type of slotted gold prosthetic retaining screw.

Material And Methods: Forty-five slotted gold prosthetic screws from the same manufacturer (Implant Innovations) were divided randomly into 9 groups of 5 screws each, with group 0X being an unused control.

Defects in hexed gold prosthetic screws: A metallographic and tensile analysis.

Statement Of Problem: Prosthetic gold screw fracture remains a clinical problem in implant prosthodontics.

Purpose: This study examined hexed gold prosthetic screws for internal defects and determined the effect of these defects on tensile strength. The microstructure, microhardness, and major constituents of the alloys also were determined.