Effectiveness of Persea major Kopp (Lauraceae) extract against Enterococcus faecalis: a preliminary in vitro study.

BACKGROUND: Persea major Kopp (Lauraceae) is a plant with wound healing, antibacterial, and analgesic properties. The aim of this study was to assess the in vitro antibacterial activity of the concentrated crude extract (CCE) and ethyl acetate fraction (EAF) of this plant against Enterococcus faecalis and compare it with calcium hydroxide [Ca(OH)2] paste and 2% chlorhexidine digluconate (CHX). METHODS: The plant material was collected, and an extract was prepared according to the requirements of the study (CCE and EAF). The minimum inhibitory concentrations (MICs) of CCE, EAF, Ca(OH)2, Ca(OH)2 + CCE, and CHX against E. faecalis were determined using the broth microdilution method RESULTS: The EAF inhibited E. faecalis at concentrations of 166.50, 83.25, and 41.62 mg mL-1, and 1.00, 0.50, and 0.25% of CHX solutions showed antimicrobial activity. The MICs of Ca(OH)2 paste were 166.50 and 83.25 mg mL-1, whereas Ca(OH)2 + CCE showed antimicrobial activity only at a concentration of 166.50 mg mL-1. CCE showed no inhibitory effect at any of the concentrations tested CONCLUSIONS: The CCE did not show any antimicrobial activity against E. faecalis; however, the EAF was the most effective among the three highest concentrations tested.

Undergraduate students introduction to manual and rotary root canal instrumentation.

The aim of this study was to evaluate the performance of undergraduates in their first contact with manual and rotary root canal instrumentation. Forty-two students who had never worked on a root canal before instrumented 42 extracted lower-incisors. Participants were assigned to one of two groups: Rotary instrumentation or manual instrumentation. Pre- and post-operative computed tomography scans were obtained with a 3-dimensional dental imaging system. Starting and finishing times of preparation were recorded. The cross-sectional area of the root canal was analyzed with 2-mm-below-the-apex initial and final transverse images recorded through a digital imaging system and analyzed with software to measure the initial and final area of the root canal in mm(2). Data from the cross-sectional area of the root canal and time spent were subjected to the Mann-Whitney's U-test (p<0.05). The rotary instrumentation group showed smaller time for preparation (p=0.0204). No differences between rotary and manual instrumentation regarding the cross-sectional area of the root canal were observed (p=0.25). No accidents occurred. Undergraduate students showed good performance in their first contact with the manual and rotary instrumentation with regard to time spent and cross-sectional area of the root canal, with no operative accidents.