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Title Antibacterial Effectiveness of Intracanal Medicaments
Clinical Question In patients undergoing endodontic treatment for apical periodontitis, should calcium hydroxide be used as the intracanal medicament of choice to reduce residual bacteria versus other available medicaments (such as phenolic derivatives, iodine–potassium iodide, chlorhexidine, and formocresol)?
Clinical Bottom Line Calcium hydroxide currently remains the best medicament available. Therefore, to maximize reduction of bacteria in the root canal before root canal filling, calcium hydroxide should be used as an inter-appointment dressing for a minimum of 7 days. (See Comments on the CAT below)
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 15448460Law/2004Patients with infected necrotic root canals, with radiographic evidence of periapical bone loss. Systematic Review
Key resultsCalcium hydroxide remains the best medicament available to reduce residual microbial flora further.
Evidence Search Search "Calcium Hydroxide"[Mesh Search "formocresol "[Substance Name], Search formocresol
Comments on
The Evidence
The variability in clinical techniques of the included studies makes definitive conclusions difficult regarding the antibacterial effectiveness of calcium hydroxide. The divergence between the studies may be partly explained by such factors as number of test teeth and tooth/canal type, instrumentation technique (hand vs. rotary nickel titanium files) and final file size, irrigants (NaOCl vs. saline), presence or absence of the smear layer, duration of calcium hydroxide dressing or any other intracanal disinfectant, method of removal of calcium hydroxide, and type of temporary restoration. Therefore, clinical trials need to be standardized in order to make a definitive recommendation to practitioners. The study was also biased in the results due to the inclusion/exclusion criteria eliminated all papers except five that evaluated calcium hydroxide. The inclusion/exclusion criteria needed to be more lenient to include trials to compare all materials, not just calcium hydroxide.
Applicability There is a strong correlation between apical periodontitis and the presence of bacteria in canals. It has been shown that it is impossible to achieve a sterile root canal system by cleaning and shaping of the canal alone. Therefore, irrigation is needed to reduce the bacterial load and practitioners will need evidence to choose the most appropriate medication for their patients.
Specialty/Discipline (Endodontics)
Keywords Calcium Hydroxide, Formocresol, Periapical Periodontitis, Root Canal Irrigants, Bacteria/drug effects.
ID# 615
Date of submission: 04/08/2010spacer
E-mail simont@uthscsa.edu
Author Tiffany Simon
Co-author(s) e-mail
Faculty mentor/Co-author James V. Potter, DDS
Faculty mentor/Co-author e-mail dentist@netdentist.com
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
post a rationale
None available
Comments and Evidence-Based Updates on the CAT
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by Michael Hosking, Jane Chadwick (San Antonio, TX) on 08/10/2013
We conducted a Pubmed search on this topic on August 5, 2013 and found more recent publications with PMID: 17546863 and 17209826 . One article is a review and the other is a systematic review. Both articles support the use of calcium hydroxide as an interappointment dressing. However, they do suggest that calcium hydroxide is not a perfect dressing and further research should be done to find a better medicament. The review by Sathorn, Parashos and Messer in 2007 conclude that calcium hydroxide has limited effectiveness in eliminating bacteria from root canals when assessed by culture techniques. The original reference cited in this CAT supports this, suggesting that the main antibacterial action is from instrumentation and irrigation with sodium hypochlorite. Chlorhexidine may be useful as an inter-appointment dressing, especially against E. faecalis (de Lucena, 2013, PMID: 22747603 ) but there is a lack clinical evidence supporting its use.

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