Fracture resistance of endodontically treated maxillary incisors restored with single or bundled glass fiber-reinforced composite resin posts
To compare the fracture resistance of endodontically treated maxillary incisors restored with single versus bundled glass fiber-reinforced composite resin posts (FRC).Twenty-four maxillary incisors underwent root canal preparation (1.5-mm-diameter post spaces after canal obturation). Teeth were randomly divided into two groups (n = 12). Two different FRC groups were used for the intracanal post treatment. Single FRC (Rebilda Post system, 1.5 mm diameter) and bundled FRC (Rebilda Post GT, 12 fiber bundles, 1.4 mm diameter) were bonded to the prepared canals using dual-cure resin-based luting cement. Specimens were kept in humid at 37°C for one day. The fracture resistance testing was perform…
Microleakage comparison of glass-ionomer and white mineral trioxide aggregate used as a coronal barrier in nonvital bleaching
Objectives: There is some evidence that the pH at the root surface is reduced by intracoronal placement of bleaching pastes, which is known to enhance osteoclastic activity. Therefore, it is recommended that a protective barrier be used over the canal filling to prevent leakage of bleaching agents. Glass-ionomer (GI) is commonly used as a coronal barrier before nonvital bleaching. Because mineral trioxide aggregate (MTA) creates high alkalinity after mixing with water, using MTA as a protective barrier over the canal filling may not only prevent leakage of bleaching agents and microorganisms, but may prevent cervical resorption. The aim of this study was to evaluate sealing ability of white…
Comparison of two histopathologic methods for evaluating subcutaneous reaction to mineral trioxide aggregate
Objectives: One of the most important factors for suitable materials for pulp therapy is biocompatibility. Two histopathologic methods of Cox and Federation Dentaire International (FDI) were used to evaluate inflammation. In Cox method, density of inflammatory cells, tissue reactions like fibrosis, vascular responses like congestion and fibrin extravasation have been used to evaluate inflammatory reactions. The aim of this study was to compare the accuracy of pathologists’ interpretations using two different methods. Study design: Three pathologists observed the degree of inflammation in 225 histopathologic sections. These sections showed inflammation in subcutaneous connective tissue of ra…
Effect of alkaline ph on sealing ability of white mineral trioxide aggregate
Objectives: The aim of this study was to evaluate microleakage of white mineral trioxide aggregate (WMTA) after its exposure to a range of alkaline environments during hydration. Study Design: Seventy single-rooted teeth were divided into 4 experimental and 2 control groups. All the teeth were instrumented, and their apices were resected. Root-end cavities were filled with WMTA in the experimental groups. In the control groups, root-end cavities were not filled. Root-end fillings were exposed to alkaline environments with pH values of 7.4, 8.4, 9.4, or 10.4 for 3 days. Microleakage was evaluated by bovine serum albumin. Evaluations were carried out at 24-hour intervals for 80 days. Data wer…