Influence of serum and necrotic soft tissue on the antimicrobial effects of intracanal medicaments.

The purpose of this study was to investigate the influence of serum and necrotic soft tissue on the antimicrobial activity of intracanal medicaments. The medicaments tested were: calcium hydroxyde/glycerin paste, calcium hydroxide/chlorhexidine paste, calcium hydroxide/camphorated paramonochlorophenol/glycerin paste, and chlorhexidine/zinc oxide paste. Survival of Enterococcus faecalis and Candida albicans exposed to the medicaments tested in the presence or absence of serum or necrotic tissue was monitored in three in vitro experiments where samples for culturing were taken at different time periods.

Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals.

Introduction: Oval-shaped root canals might represent a great challenge for proper disinfection. This study compared the capability of a newly developed instrument, the self-adjusting file (SAF), and rotary nickel-titanium (NiTi) instrumentation to eliminate Enterococcus faecalis populations from long oval root canals of extracted human teeth. As a secondary purpose, the ability of a modification in sampling technique to recover bacteria lodged in recesses of oval canals was evaluated.

Effects of electropolishing surface treatment on the cyclic fatigue resistance of BioRace nickel-titanium rotary instruments.

Introduction: This study evaluated the influence of electropolishing surface treatment on the number of cycles to fracture of BioRace rotary nickel-titanium endodontic instruments.

Methods: BioRace size BR5C instruments with or without electropolishing surface treatment were used in an artificial curved canal under rotational speed of 300 rpm until fracture. Fractured surfaces and the helical shafts of fractured instruments were analyzed by scanning electron microscopy (SEM).

Cyclic fatigue resistance of ProTaper Universal instruments when subjected to static and dynamic tests.

Objective: This study evaluated the number of cycles to fracture of ProTaper Universal S2 instruments when subjected to static and dynamic cyclic fatigue tests.

Study Design: ProTaper Universal S2 instruments were used until fracture in an artificial curved canal under rotational speed of 300 rpm in either a static or a dynamic test model. Afterward, the length of the fractured segments was measured and fractured surfaces and helical shafts analyzed by scanning electron microscopy (SEM).

Photodynamic therapy with two different photosensitizers as a supplement to instrumentation/irrigation procedures in promoting intracanal reduction of Enterococcus faecalis.

Introduction: This in vitro study aimed to investigate the antibacterial effects of photodynamic therapy (PDT) with methylene blue (MB) or toluidine blue (TB) (both at 15 microg/mL) as a supplement to instrumentation/irrigation of root canals experimentally contaminated with Enterococcus faecalis.

Methods: Seventy extracted teeth had their root canals contaminated with an endodontic strain of E. faecalis for 7 days, instrumented with nickel-titanium instruments and irrigated either with 2.

Comparison of the effectiveness of three irrigation techniques in reducing intracanal Enterococcus faecalis populations: an in vitro study.

Introduction: Several irrigation techniques have been recently introduced with the main objective of improving root canal disinfection. This in vitro study aimed at comparing the intracanal bacterial reduction promoted by chemomechanical preparation with 3 different irrigation techniques.

Methods: Root canals from extracted teeth were contaminated with Enterococcus faecalis ATCC 29212 for 7 days and then randomly distributed into 3 experimental groups of 20 teeth each: group 1, conventional irrigation with NaviTip needles inserted up to 3 mm short of the working length; group 2, same as group 1, but supplemented with final irrigant activation by the EndoActivator system; and group 3, irrigation with the EndoVac system.

Influence of rotational speed on the cyclic fatigue of rotary nickel-titanium endodontic instruments.

Introduction: During the preparation of curved canals, rotary nickel-titanium (NiTi) instruments are subjected to cyclic fatigue, which can lead to instrument fracture. Although several factors may influence the cyclic fatigue resistance of instruments, the role of the rotational speed remains uncertain. This study was intended to evaluate the effects of rotational speed on the number of cycles to fracture of rotary NiTi instruments.

Postoperative pain following the use of two different intracanal medications.

This study evaluated the incidence of postoperative pain after intracanal dressings with either 0.12% chlorhexidine digluconate gel (CHX) or a calcium hydroxide/camphorated paramonochlorophenol/glycerin paste (CH/CPMC). Overall, 138 asymptomatic teeth had their canals instrumented under irrigation with 2.

On the use of denaturing gradient gel electrophoresis approach for bacterial identification in endodontic infections.

Bacteria in infected root canals of teeth evincing chronic apical periodontitis lesions were identified by a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) approach. DNA was extracted from root canal samples, and part of the 16S rRNA gene of all bacteria was amplified by PCR and separated by DGGE, generating banding patterns representative of the community structure. Twenty visible bands were cut out of the gel, re-amplified, and sequenced to provide identification.