1,720,966 research outputs found
Cone-beam-computed-tomography of the symmetry of root canal anatomy in mandibular incisors
No full textOpen-Access-Publikationsfonds 202
Root canal preparation using S5, Mtwo, and ProTaper Universal nickel-titanium systems: a comparative ex-vivo study
No full textTo examine various parameters of root canal preparation using three rotary nickel-titanium systems (S5, Mtwo, and ProTaper Universal [PTU])
Sensitivity of conventional radiographs and cone-beam computed tomography in detecting the remaining root-canal filling material
No full textOpen-Access-Publikationsfonds 202
Cleanliness and erosion of root canal walls after irrigation with a new HEDP-based solution vs. traditional sodium hypochlorite followed by EDTA. A scanning electron microscope study
No full textReparatur statt Austausch
No full textZiel der Studie: Amalgam kommt bei der Anfertigung neu- er Restaurationen immer seltener zur Anwendung, jedoch verfügen viele PatientInnen über bereits bestehende Amal- gamrestaurationen. Dementsprechend bedarf es Reparatur- techniken, die geeignet sind, partiell insuffiziente Amalgam- restaurationen zu reparieren. Ziel dieser Studie war es daher, die Reparierbarkeit von Komposit und Amalgam in Abhängig- keit von verschiedenen mechanischen und chemischen Ober- flächenvorbehandlungen zu untersuchen und zu vergleichen.
Material und Methode: Komposit- und Amalgamprüfkörper wurden im Thermolastwechselverfahren (10.000 Zyklen, 5 – 55°C) künstlich gealtert und per Zufallsverfahren drei verschiedenen mechanischen Oberflächenbearbeitungen zugeführt: Anrauen, Sandstrahlen mit Aluminiumoxid oder Silikatisieren. In den entsprechenden Kontrollgruppen fand keine mechanische Oberflächenbearbeitung statt. Anschlie- ßend wurde entweder ein konventionelles Bonding oder ein Universaladhäsiv und darauffolgend ein Reparaturkomposit aufgebracht (je Untergruppe n = 16). Nach erneuter Alterung wurden die Scherfestigkeiten bestimmt und die Versagens- muster untersucht. Die statistische Auswertung erfolgte mit- tels ANOVA, Zweistichproben-t-Tests, Weibull-Statistik und Chi2-Test (p < 0,05).
Ergebnisse: Unabhängig von der Art der Vorbehandlung wa- ren die Reparaturfestigkeiten auf Amalgam signifikant gerin- ger als auf Komposit (p < 0,02). Verglichen mit der jeweiligen Kontrollgruppe führte eine mechanische Vorbehandlung sowohl auf Komposit als auch auf Amalgam zu signifikant höheren Haftwerten. Die Applikation des Universaladhäsivs führte auf Amalgam-Prüfkörpern in allen Untergruppen zu signifikant besseren Haftwerten als das konventionelle Bon- ding. Dies war bei Komposit nur in der Kontrollgruppe und bei Anrauen der Oberfläche der Fall. Die Versagensmuster waren signifikant abhängig vom Material sowie der mechanischen und chemischen Vorbehandlung (p < 0,001). Die mechanische Oberflächenvorbehandlung führte dabei zu einem signifikant geringeren Anteil adhäsiver Versagensmuster.
Zusammenfassung: Insuffiziente Amalgamrestaurationen sind potenziell für Reparaturen mit Komposit geeignet, aller- dings werden geringere Reparaturhaftwerte als auf Komposit erzielt
Debris Removal Using a Hydroxyapatite Nanoparticle-Containing Solution (Vector Polish) with Sonic or Ultrasonic Agitation
Full text linkChemomechanical preparation of the root canal system is considered to be the most important part of root canal treatment, including both mechanical removal of tissue remnants and dentine chips, and chemical elimination of biofilm and microorganisms. A number of different solutions and agitation techniques have been proposed for that purpose. It was the aim of the present study to investigate whether root canal cleanliness can be improved by using a hydroxyapatite nanoparticle-containing solution with and without sonic or ultrasonic agitation. Seventy-four single-rooted teeth were divided into four experimental groups (n = 15) and two control groups (n = 7). All teeth were split longitudinally and a groove and three holes were cut into the root canal wall and filled with dentinal debris. Final irrigation was performed using sodium hypochlorite or a hydroxyapatite nanoparticle-containing solution (Vector polish) activated with a sonically or an ultrasonically driven endodontic file. Two calibrated investigators rated the remaining debris using a four-score scale. The results were analyzed using a non-parametric test with α < 0.05. Sonic and ultrasonic irrigation with sodium hypochlorite cleaned the grooves and holes well from debris. The hydroxyapatite nanoparticles activated by a sonic file cleaned grooves and holes equally well. Ultrasonically activated nanoparticles performance was clearly inferior. The syringe control-group left large amounts of debris in grooves and holes. The use of the hydroxyapatite nanoparticles used in this study did not improve removal of debris
Removal of Thermafil Obturators Using 2 Different Techniques: A Comparative Ex Vivo Study
No full text
Effect of preparation size on the removal of accumulated hard-tissue debris from the mesial root canal system of mandibular molars using SWEEPS technology
No full textAbstract Objectives This study assessed the influence of preparation size on the efficacy of shock wave–enhanced emission photoacoustic streaming (SWEEPS) and conventional irrigation (CI) on removal of accumulated hard tissue debris (AHTD) from isthmus-containing mandibular molars using micro-computed tomographic analysis. Materials and methods Sixty extracted mandibular molars with two mesial canals connected by an isthmus were selected. Canals were shaped with Mtwo instruments (VDW, Munich, Germany) up to sizes 25/.06, 40/.04 or 40/.06 ( n = 20), and specimens were distributed into 2 final irrigation groups ( n = 10): SWEEPS and CI. Roots were scanned at a resolution of 10.5 µm before and after preparation and final irrigation. Data sets were co-registered, and the percentage reduction of AHTD calculated for each specimen was statistically compared using analysis of variance with a of 5% significance level. Results The preparation size did not significantly influence the percentage reduction of AHTD ( p < 0.05), whereas the final irrigation technique had a significant effect on debris removal ( p < 0.05). A significant reduction of AHTD was achieved after final irrigation in all groups ( p < 0.05); however, SWEEPS was associated with a significantly greater percentage reduction of debris than CI ( p < 0.05). None of the specimens presented a completely clean isthmus. Conclusions Removal of AHTD was not significantly affected by the preparation size. SWEEPS was associated with significantly less debris than CI. Clinical relevance SWEEPS performed significantly better than CI regarding the removal of AHTD from isthmus-containing mandibular molars irrespective of the preparation size
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