Push-out bond strength of different root canal obturation systems to root canal dentin

AbstractAimTo evaluate and compare push-out bond strength of four obturation systems; Gutta-percha/AH Plus, GuttaFlow, RealSeal and EndoREZ system to root canal dentin.Materials and methodsHuman freshly extracted 80 mandibular premolars were prepared and assigned to experimental groups (n = 20), designated as Group I: Gutta-percha/AH Plus, Group II: GuttaFlow system, Group III: RealSeal points/RealSeal Self-etch and EndoREZ obturation system. After obturation, each tooth was prepared for push-out assessment with root slices of 2 mm thickness using universal testing machine. Data were analyzed using one way ANOVA in a level of confident at 95%.ResultsGutta-percha/AH Plus root fillings showed significantly highest bond strength. Whereas root segment location did not have a significant influence on bond strength except with Group III.ConclusionThe adhesiveness quality to root dentin promoted by newer methacrylate resin-based obturation systems like RealSeal and EndoREZ systems is compromised even when teeth with simple anatomic features were obturated under well-monitored laboratory conditions

Cleaning efficacy of different root canal preparation systems and irrigation regimens

AbstractPurposeTo compare the cleaning efficacy of root canal walls after using two Nickel–Titanium (Ni–Ti) rotary files (Flexmaster and Mtwo) and one hand Ni–Ti file (Ni–Ti flex-K) when associated with different final irrigation regimens (SmearClear, 17% ethylene diamine tetra acetic acid (EDTA) and sodium hypochlorite).Materials and methodsNinety extracted human premolars with similar range of canal curvature (21–39°) were selected. After crown removal and working length determination, roots were divided into three equal groups according to root canal instrumentation: Group I and Group II were prepared using Flexmaster, Mtwo Ni–Ti rotary systems respectively where Group III was prepared using hand NiTi flex-K files. Each group was further subdivided into three equal subgroups according to root canal final irrigation; subgroup A: SmearClear, subgroup B: 17% EDTA and subgroup C: NaOCl. Roots were then splitted longitudinally and processed for scanning electron microscopic (SEM) examination to evaluate and score the root canal cleanliness.ResultsFinal root canal irrigation using either SmearClear or 17% EDTA had significantly better cleaning efficiency than that of NaOCl in all tested groups. Ni–Ti hand files had significantly less cleaning efficacy than that of rotary systems except in subgroup C using NaOCl