The nonlinear dynamic model of rotor-bearing-seal system with crack in shaft is set up based on the coupling model of nonlinear oil-film force and Muszyska’s nonlinear seal fluid force. The dynamic vibration characteristics of the rotor-bearing-seal system and the effects of physical and structural parameters of labyrinth seal and crack fault on movement character of the rotor were analyzed. Th...

BACKGROUND Microbial contamination of the pulp space is one of the major factors associated with endodontic failure. Thus, in addition to a three dimentional apical filling a coronal seal for root canal fillings has been recommended. AIM The present study was conducted to evaluate and compare the intra-orifice sealing ability of three experimental materials after obturation of the root canal ...

This in vitro study evaluated the sealing efficacy of three root-filling systems/techniques in preventing bacterial leakage. Instrumented single-rooted root segments were filled with (1) warm vertical compaction with gutta-percha/AH Plus; (2) single-cone technique with ActiV GP; and (3) single-cone technique with Gutta-Flow. A dual-chamber leakage model using S. mutans as a microbial marker was...

Root canal filling materials, including sealercement and obturation points or cones, are used in root canal treatment to occlude the apical portion of the canal. These will block the dentinal tubules preventing passage of tissue fluids, toxins, and microorganisms into the root canal space. Many investigators have demonstrated the importance of a sealer cement for effective root canal obturation...

OBJECTIVE There is some concern that root resection may alter the seal of the previously set orthograde material. The aim of this study was to evaluate the apical sealing ability of orthograde mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) plugs after resection of the roots. MATERIALS AND METHODS The fluid filtration method was carried out on a total of 51 roots in three ...

AIM To evaluate retention of complete denture base with different types of posterior palatal seals. MATERIAL AND METHODS Ten male patients between the age group of 50 years to 60 years were selected for the study. After the primary and secondary impressions were taken, five casts were made including a cast without posterior palatal seal, a cast with single bead posterior palatal seal, a cast ...

Abstract Introduction Insufficient seal of apex is a significant reason for an endodontist’s disappointment. The materials root-end filling utilized ought to forestall departure possible pollutants into periapical areas. objective this analysis was compare the fixing capacity three materials: white mineral trioxide aggregate (MTA), Portland cement (PC), and Biodentine. This analyzed through tes...

OBJECTIVE The purpose of this study was to analyze the ability of multiple compounds to seal the dental tubules using scanning electron microscopy (SEM) and micro-computed tomogra-phy (micro-CT). MATERIAL AND METHODS Twenty-four single-root human mandibular premolars were selected and instrumented with nickel-titanium rotary file and the final file size was #40/06. They were then randomly all...