An abutment for a fixed partial denture may not contain enough tooth structure, such that the abutment does not provide an adequate 'ferrule effect'. A crown or bridge dental prosthesis that is cemented onto such an abutment/s may undergo biomechanical failure. Here, the tooth, core, and post complex, on which the crown is cemented, may fracture off from the abutment, causing the crown to separ...

STATEMENT OF PROBLEM Unresolved controversy exists concerning the remaining coronal tooth structure of anterior endodontically treated teeth and the best treatment option for restoring them. PURPOSE The purpose of this study was to evaluate the effect of post, core, crown type, and ferrule presence on the deformation, fracture resistance, and fracture mode of endodontically treated bovine inc...

PURPOSE This study evaluated fracture resistance with regard to ferrule lengths and post reinforcement on endodontically treated mandibular premolars incorporating a prefabricated post and resin core. MATERIALS AND METHODS One hundred extracted mandibular premolars were randomly divided into 5 groups (n=20): intact teeth (NR); endodontically treated teeth (ETT) without post (NP); ETT restored...

We have developed a 7-core-fiber connector. To maintain both the ferrule floating mechanism and precise alignment around the ferrule axis, we employed Oldham's coupling mechanism inside the MUtype connector plug housing and realized an average attenuation of 0.13 dB and an average return loss of 46.8 dB.

STATEMENT OF PROBLEM Studies concerning the effects of post-core design and ferrule on the fracture resistance of endodontically treated teeth remain controversial. PURPOSE The purpose of this study was to investigate in vitro the effects of post-core design and ferrule on the fracture resistance of root canal treated human maxillary central incisors restored with metal ceramic crowns. MATE...

PURPOSE To evaluate the effect of ferrule preparation length on the fracture resistance after simulated surgical crown lengthening and after forced tooth eruption of endodontically-treated teeth restored with a carbon fiber-reinforced post-and-core system. METHODS 40 extracted endodontically-treated mandibular first premolars were decoronated 1.0 mm coronal to the buccal cemento-enamel juncti...

A compact optical package for mounting a VCSEL or PIN array has been developed. Each package couples an array to a fiber ribbon terminated with a commercial MT ferrule. The package is fabricated with beryllium oxide (BeO), allowing efficient removal of the heat produced by the array. The package is quite compact as it is significantly smaller than an MT ferrule. The design simplifies testing an...

The intraradicular reinforcement of structurally compromised roots has been advocated for endodontically treated teeth with thin remaining walls. The purpose of this in vitro study was to investigate the validity of intraradicular reinforcement. After the crowns were removed, forty structurally weakened central incisors were divided into two main groups for morphologic dowel rehabilitation or r...

This study investigated the effect of fiber reinforced composite resin (FRC) post lengths, ferrule, and full coverage metal crown on fracture resistance of endodontically treated teeth (ETT) using an experimental FRC post with the similar elastic modulus of dentin (11.5 GPa). ETT was restored according to 1 of 7 combinations of FRC post length (10, 5, 2.5, 0 mm), ferrule (0, 2 mm), and with/wit...