Effect of remaining coronal structure on the resistance to fracture of crowned endodontically treated maxillary first premolars.

Objective: Endodontically treated maxillary first premolars present a restorative challenge. The objective of the present study was to assess the resistance to fracture of crowned endodontically treated maxillary first premolars under simulated occlusal load, while preserving various degrees of remaining coronal structure.

Methods And Materials: The study consisted of 50 intact maxillary first premolars with bifurcated roots and similar root diameter and length, randomly divided into 5 equal experimental groups.

Effect of reduced post length on the resistance to fracture of crowned, endodontically treated teeth.

Objective: To examine the influence of a reduced post length sealed with a titanium-reinforced composite luting agent on the fracture resistance of crowned endodontically treated teeth with a 2-mm ferrule on healthy tooth structure.

Method And Materials: The study consisted of 60 intact single-rooted premolars with similar root diameters and lengths. Teeth were endodontically treated and randomly divided into 6 experimental groups (n = 10) with various post lengths (5, 8, and 10 mm) and types (ParaPost and Dentatus) of equal diameter.

Resistance to fracture of crowned endodontically treated premolars restored with ceramic and metal post systems.

Objectives: The objective of this study was to assess the resistance to fracture of crowned endodontically treated premolars with varying ceramic and metal post systems under simulated occlusal load.

Method And Materials: The study consisted of 60 extracted intact premolars with similar root diameter and length. Teeth were divided equally into 4 groups (n = 15) and prepared for posts and cast crowns as follows: group 1 = preformed metal post, composite core, and cast crown; group 2 = cast post and core and cast crown; group 3 = zirconia post, composite core, and cast crown; and group 4 = zirconia post and heat-pressed ceramic core and cast crown.

Heat transfer of impression plasters to an implant-bone interface.

Purpose: The purpose of this in vitro study was to measure heat generated at the implant-bone interface caused by exothermic setting reaction of 2 impression plasters.

Materials And Methods: The study consisted of 20 titanium-alloy abutment impressions connected to a titanium-alloy cylindrical implant embedded in an acrylic-resin mandible in a 37 degrees C water bath. There were 2 types of impression plaster used, Snow-White (Kerr, Romulus, MI) and Xantano (Kulzer, Dormagen, Germany).

Assessment of the resistance to fracture of endodontically treated molars restored with amalgam.

Statement Of Problem: Controversy exists concerning the preferred type of final restoration of endodontically treated molars regarding their resistance to fracture under occlusal load.

Purpose: The aim of this study was to assess the resistance to fracture of endodontically treated molars with various degrees of tooth structure loss restored with amalgam under simulated occlusal load.

Material And Methods: .

Effect of core stiffness on the in vitro fracture of crowned, endodontically treated teeth.

Statement Of Problem: Dentin and core materials that substitute for missing dentin are dissimilar materials. A core material with a lower elastic modulus may deform more under applied stress and therefore result in reduced stress concentration at the core/dentin junction.

Purpose: This in vitro study examined the effect of core stiffness on the fracture resistance and failure characteristics of a crowned, endodontically treated tooth under simulated occlusal load.

Impression technique for partially edentulous patients.

This article describes an implant impression technique for partially edentulous patients in which impression plaster and irreversible hydrocolloid are used. The technique ensures accuracy, ease of manipulation, and decreased working time.