In vitro diffusion of hydroxyl ions from medicaments pastes based on calcium hydroxide

Liza Porcaro de Bretas, Cristiane Ferreira Alfenas, Annelisa Farah da Silva, Maria das Graças Afonso Miranda Chaves, Celso Neiva Campos

Objective: Analyzing, in vitro, the pH of six endodontic pastes based on calcium hydroxide [Ca (OH) 2]. Methods: Six groups were formed (n = 5 pastes/group) and a control group (distilled water): GI – Ca(OH)2, propylene glycol 400 (PEG 400) and camphorated paramonochlorophenol (PMCC); GII - Ca(OH)2, iodoform 1:1, PEG 400 and PMCC; GIII – Ca(OH)2, iodoform 4:1, PEG 400 and PMCC; GIV - Ca(OH)2 and Otosporim®; GV – Ca(OH)2 and olive oil; GVI - Ca(OH)2 and chlorhexidine gel 2%. The pastes were previously placed in distilled water and stored at 37° C, and the pH of each sample was measured at seven different time intervals. The assay was performed in two steps, whereas in the second stage the distilled water was replaced after each reading. Results: In both phases, there was no statistically significant difference between the pH values of GI, GII, GIII and GIV (p > 0.05) in the 7 time intervals evaluated. All groups showed higher pH compared to the GV and the control group (p < 0.05), which were statistically similar to each other (p > 0.05). Conclusion: The pastes presented alkaline pH, with variations according to their composition, having a greater dissociation when a viscous substance was present in the composition.

Keywords: Diffusion. Endodontics. Calcium hydroxide.

How to cite: Bretas LP, Alfenas CF, Silva AF, Chaves MGAM, Campos CN. In vitro diffusion of hydroxyl ions from medicaments pastes based on calcium hydroxide. Dental Press Endod. 2012 July-Sept;2(3):36-41.

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