A three-dimensional finite element analysis of the effects of restorative materials and post geometry on stress distribution in mandibular molar tooth restored with post-core crown.
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This study investigated the effects of crown material, post material, and post geometry on stress distribution in molar tooth restored with post-core crown. A three-dimensional solid model consisting of the mandibular second molar tooth, periodontal ligament, cortical bone, and spongy bone was generated. Finite element analysis results showed that prefabricated posts with a composite resin core increased stress concentration at the cementoenamel junction (CEJ), while cast posts induced high stress at post-dentin interface. Increase in the elastic modulus of crown material also increased the stress concentration, especially at CEJ. (+info)
Treatment of perforating internal root resorption with MTA: a case report.
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Endodontic treatment of teeth with perforating internal root resorption represents a clinical challenge. In most cases, extraction of the tooth and subsequent replacement with an osseointegrated implant is indicated. Presented herein is a case report of a maxillary lateral incisor with advanced perforating internal root resorption in the middle third of the root and the presence of a sinus tract. Mineral Trioxide Aggregate (MTA) was used with the aid of a surgical microscope in order to fill the resorption area after conventional root canal therapy of the apical segment. At the follow-up after 11 years and 8 months, the patient was clinically asymptomatic and the sinus tract had disappeared. The radiographic examination and computerized tomography indicated periodontal bone repair. (+info)
Rigidity, retention, and resistance of titanium versus double taper light root canal posts: an in vitro evaluation.
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Microbial diversity in failed endodontic root-filled teeth.
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BACKGROUND: Persistent/secondary infections of human root canals play an important role in the failure of endodontic treatment. This study used 16S rRNA sequencing to assess microbial diversity in root-filled teeth associated with failed endodontic treatment. METHODS: DNA was extracted from 15 teeth with persistent intraradicular infections, and the 16S rRNA of all present bacteria were amplified by PCR, followed by cloning and sequencing of the 16S rRNA amplicons. RESULTS: All sample extracts were positive for PCR amplification using the universal 16S rRNA gene primers. Negative control reactions yielded no amplicons. Sixty-five phylotypes belonging to seven phyla were identified from 760 clones; a mean of 9.4 phylotypes were detected in each sample (range 3 - 15). Twenty-eight phylotypes were detected in more than one sample, revealing a high inter-sample variability. Parvimonas micra (60%, 9/15), Solobacterium moore (47%, 7/15), Dialister invisus (33%, 5/15), Enterococcus faecalis (33%, 5/15), Filifactor alocis (27%, 4/15), and Fusobacterium nucleatum (27%, 4/15) were the prevalent species. Nineteen as-yet-uncultivated phylotypes were identified, comprising a substantial proportion of the bacteria in many cases. CONCLUSIONS: Persistent intraradicular infections were present in all root-filled teeth associated with failed endodontic treatment. The current observations reveal new candidate endodontic pathogens, including as-yet-uncultivated bacteria and phylotypes that may participate in the mixed infections associated with post-treatment apical periodontitis. (+info)
Probable biofilm formation in the cheek as a complication of soft tissue filler resulting from improper endodontic treatment of tooth 16.
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