A study of the time necessary for calcium hydroxide to eliminate microorganisms in infected canals

Abstract

The objective of this study was to analyze the time necessary for calcium hydroxide to eliminate microorganisms in infected canals. A total of 168 human anterior teeth were prepared and sterilized. One hundred sixty two teeth were inoculated with suspensions of S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans. Three teeth were used as negative control and three as positive control. Root canals were irrigated with saline and filled with calcium hydroxide paste (CHP). At intervals of 1 minute, and at 7, 15, 21, 27, 30, 45, 60, and 90 days, CHP was removed, samples were collected and immersed in Letheen Broth (LB). Microbial growth was analyzed by two methods, turbidity of the culture medium and subculture on a Brain heart Infusion. After looking for medium change, an inoculum of 0.1 mL obtained from LB was transferred to 7 mL of Brain Heart Infusion (BHI), and subsequently incubated at 37°C for 48 hours. Microbial growth was checked by turbidity of the culture medium and in some cases by Gram stain. All assays were carried out in triplicate under aseptic technique. The results indicated that the antimicrobial effect on the cultures of S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans and one mixed culture in infected canals by CHP occurred in 60 days.

Antimicrobial potential of medicaments used in healing process in dogs' teeth with apical periodontitis

“…The results of this study, using the described methodology, are in accordance with the findings of other research (2,(5)(6)(7)20). Kvist et al (20) analyzed the antimicrobial efficacy of endodontic procedures performed in one session (including a 10-min intra-session dressing with 5% iodine-potassium-iodide) compared to a two-visit treatment (including an inter-session dressing with CHP).…”

“…The effectiveness of intracanal dressings on the success rate in teeth with apical periodontitis has been discussed (1)(2)(3)(4)(5)(6)(7)(8). Byström et al (2) recovered bacteria from one of 35 root canals treated by calcium hydroxide paste (CHP) after 30 days and suggested that the endodontic treatment of infected root canals can be completed in two sessions when CHP is used as an intracanal dressing.…”

Calcium hydroxide associated with a new vehicle: Psidium cattleianum leaf extracts. Tissue response evaluation

“…However, some microorganisms such as Enterococcus faecalis and Candida albicans are more resistant to Ca(OH) 2 . 6,13,14 Different microorganisms exhibit different levels of resistance to Ca(OH) 2 activity, and new vehicles or products that improve the effects of Ca(OH) 2 are being explored.…”

Calcium hydroxide: study based on scientific evidences

“…Two effects of this medication need to be considered, biological and antimicrobial effects 5,30,31 . Thus, others factors can alter this effects, like the influence of vehicles in this properties and the time of action for to express microbial control 3,[6][7][8][11][12][13][15][16][17][18][19][20][21][22][23][24][25][26][27][29][30][31][32]35,37,42,44,60,81,82,105,110,117 . Other substances with objectives similar to calcium hydroxide, like Mineral Trioxide Agregate and Portland cement, have also been studied 9,76,78,79,88,89,94,99,100,108,113,119,120,123 .…”

“…The maintenance of a high concentration of hydroxyl ions can change enzymatic activity and promote its inactivation. The elimination of microorganisms by calcium hydroxide paste in infected root canal in vitro occurred in 60 days when saline solution was chosen as endodontic irrigant to avoid masking the antimicrobial potential of calcium hydroxide paste 16 . However, the endodontic irrigant can influence the microbial control positively 14 .…”