Susceptibilties of Two Enterococcus faecalis Phenotypes to Root Canal Medications

Abstract

This study aimed to investigate and compare the efficacy of selected root canal irrigants and a medicament on a clinical isolate of Enterococcus faecalis grown as biofilm or planktonic suspension phenotype. A cell-dense pellet "presentation" prepared from planktonic phenotype was also tested. Each bacterial presentation was exposed to calcium hydroxide (pH 12.3), 0.2% chlorhexidine gluconate, 17% ethylene-diamine-tetra-acetic acid, 10% povidone iodine, or 3.0% sodium hypochlorite (NaOCl) for a range of time periods (1, 2, 4, 8, 15, 30, and 60 min). Phosphate buffered saline was used as a control agent. The difference in gradients of bacterial killing among the biofilm, planktonic suspension or pellet presentation was significant (p < 0.05) and dependent upon the test agent except in the case of NaOCl and calcium hydroxide where no difference could be detected. NaOCl was the most effective agent and achieved 100% kills for all presentations of E. faecalis after a 2 min contact time.

Tissue inflammatory response to implantation of calcium hydroxide and iodoform in the back of rats

“…It could be noticed that the CHG was always one experimental period behind the IG and this group was one experimental period behind the control wound, which means that repair in the IG was faster than in the CHG. The results found for the quantitative analysis could relate the histological and clinical findings (10,12,13,15,18). The presence of inflammatory cells (macrophages, lymphocytes and neutrophils) was higher in the control wound after three days and similar after five days.…”

“…Due to bacterial characteristics of contamination and resistance (13,16,17), as well as root canal anatomic variations, the use of an intracanal medication might be necessary for an additional decontamination (7,8,11) . This medication may act by eliminating the contamination and/ or creating unsuitable conditions for the development and establishment of these microorganisms and by stimulating the host inflammatory response in order to eliminate the aggression factors (7)(8)(9)11,13,15). In this investigation, iodoform and calcium hydroxide were inserted in the back of rats, so that the action of these drugs on tissue could be investigated (19,20).…”

“…Iodoform seems to stimulate immunological response by promoting the growth of granulation tissue, and thus accelerating the healing process (14). These two drugs have a high rate of success in the treatment of periapical lesions (8,11,13,15) . , and show similar antibacterial activity in in vitro evaluations (10).…”

“…Whenever the drugs are inserted into the canal, a direct contact between the drugs and the tissue in the apical area might happen. This contact of the dugs with connective tissue, whether accidental or not, has proved to be effective in eliminating the contamination (10,11,15). However, in this case, the citotoxicity of these drugs must be assessed.…”

Çeşitli Antiseptik Taşıyıcılarla Karıştırılan Kalsiyum Hidroksitin Enterococcus faecalis üzerindeki Antimikrobiyal Etkinliği

“…Bir dezavantaj olarak, kök kanal morfolojisi, dentinin dansitesi, dentinin kalsifikasyon derecesi, dentin tübülü içeriği gibi değişkenler bu modelde standardizasyonu güçleştirmektedir. 16 Bu çalışmada kullanılan koloni sayma metodu, çeşitli koşullar altında bölünebilme yeteneğine sahip olan ve hayatta kalabilen mikroorganizmalar ile ilgili bilgi sunmaktadır. 17 Fakat dentin tübüllerinde canlı olarak kalan ama kültüre edilemeyen bakteriler de bulunabilir.…”