Prevalence of Enterococcus faecalis and Porphyromonas gingivalis in infected root canals and their susceptibility to endodontic treatment procedures: a molecular study.

Introduction: Because apical periodontitis is recognizably an infectious disease, elimination or reduction of intracanal bacteria is of utmost importance for optimum treatment outcome.

Objective: The prevalence of Enterococcus faecalis and Porphyromonas gingivalis in infected root canals was studied Also, the effect of endodontic therapy by using intracanal medicaments, calcium hydroxide paste (CH) or gutta-percha points containing calcium hydroxide (CH-GP) or chlorhexidine (CHX-GP) on these microorganisms was assessed by polymerase chain reaction (PCR) assay.

Methods: Fifty-one patients with chronic apical periodontitis were randomly allocated in one of the fol- lowing groups according to the intracanal medicament used: CH, CH-GP and CHX-GP group.

Effect of the source of biofilm bacteria, level of biofilm maturation, and type of disinfecting agent on the susceptibility of biofilm bacteria to antibacterial agents.

Introduction: Biofilm development is a dynamic process that begins with the initial attachment of planktonic bacteria to a surface, eventually leading through different stages to a mature, structurally complex biofilm. The aim of this study was to assess the effect of the source of biofilm bacteria, the level of biofilm maturation, and the type of disinfecting agent on the susceptibility of biofilm bacteria to antibacterial agents.

Methods: Multispecies biofilms from plaque bacteria of 6 donors were grown for up to 8 weeks on collagen-coated hydroxyapatite disks.

Biocompatibility of two novel root repair materials.

Introduction: The purpose of the present study was to evaluate the biocompatibility of 2 root-end filling materials, Endosequence Root Repair Material Putty (ERRM Putty) and Paste (ERRM Paste) and compare them with gray mineral trioxide aggregate (MTA).

Methods: ERRM Putty, ERRM Paste, MTA, intermediate restorative material (IRM), and Cavit G were tested. For cytotoxicity assay, human gingival fibroblasts were incubated for 1, 3, and 7 days with extracts of varying concentrations from materials set for 2 days or 7 days.

Antimicrobial efficacy of chlorhexidine against bacteria in biofilms at different stages of development.

Introduction: Detailed knowledge on the nature of the physiological and metabolic phases of biofilm development is important in combating resistant, disease-associated biofilms. The aim of this study was to examine the susceptibility of multispecies biofilms at different phases of growth to root canal irrigants.

Methods: The multispecies biofilms were grown from plaque bacteria on collagen-coated hydroxyapatite discs in brain-heart infusion broth for time periods ranging from 2 days to several months.

Bacterial viability in starved and revitalized biofilms: comparison of viability staining and direct culture.

Objectives: The aim of this study was to enumerate viable bacteria at different growth stages of a multispecies oral biofilm and to compare results obtained with the LIVE/DEAD BacLight Kit (Molecular Probes, Eugene, OR) with those from culturing and plate counting (colony-forming unit counts [CFUs]).

Methods: The multispecies biofilm was grown from plaque bacteria on collagen-coated hydroxyapatite disks in brain-heart infusion broth for 3 weeks (phase І) with a weekly addition of new nutrients. This was followed by a 9-week nutrient-deprivation phase (phase ІІ); after which, the biofilm was reactived again by weekly additions of fresh BHI medium for 4 weeks (phase ІІІ).

Tissue dissolution by sodium hypochlorite: effect of concentration, temperature, agitation, and surfactant.

Aim: Sodium hypochlorite is the most commonly used endodontic irrigant because of its antimicrobial and tissue-dissolving activity. The aim of this study was to evaluate and compare the effects of concentration, temperature, and agitation on the tissue-dissolving ability of sodium hypochlorite. In addition, a hypochlorite product with added surface active agent was compared with conventional hypochlorite solutions.

The synergistic antimicrobial effect by mechanical agitation and two chlorhexidine preparations on biofilm bacteria.

Introduction: Irrigation of the root canal with antibacterial solutions is considered an essential part of root canal treatment in endodontics. The purpose of this study was to investigate whether mechanical agitation (ultrasonic or sonic) improves the effectiveness of chlorhexidine against biofilm bacteria in vitro.

Methods: Collagen-coated hydroxyapatite (CHA) disks were exposed to dispersed subgingival plaque for 3 weeks at 37 degrees C.

Temporal analysis of the spontaneous baroreceptor reflex during mild emotional stress in the rat.

The effect of emotional stress on the spontaneous baroreceptor reflex (sBRR) in freely moving rats was investigated. Six male Wistar rats equipped with an intra-arterial polyethylene catheter were exposed to a 2-min air-jet stress. For time course analysis of the sBRR response to stress, the records of systolic blood pressure (SBP) and pulse interval (PI) were divided into five regions: baseline (BASELINE), acute exposure to air-jet stress (STRESS), immediate recovery (IMMED.

Central vasopressin V(1a) and V(1b) receptors modulate the cardiovascular response to air-jet stress in conscious rats.

This study investigates the contribution of central vasopressin receptors in the modulation of systolic arterial pressure (SAP) and heart rate (HR) response to air-jet stress in conscious Wistar rats equipped with a femoral arterial catheter and intracerebroventricular cannula using novel non-peptide and selective vasopressin V(1a) (SR49059) and V(1b) (SSR149415) antagonists. The effects of stress on SAP and HR were evaluated by measuring the maximal response to stress, the latency of the maximal response, the duration of the recovery period, and the increase in the low frequency (LF) short-term variability component. Stress induced a parallel and almost immediate increase in both SAP and HR, followed by enhanced LF SAP variability in the recovery period.