title: An in vitro evaluation of environmental pH changes after root canal therapy with three different types of calcium hydroxide.
abstract: OBJECTIVE
  This study determined environmental pH changes after root canal dressing using 3 types of commercial calcium hydroxide pastes.
  
  
  METHODS
  Thirty-two extracted single-rooted human premolars with 1 straight root canal were selected. Standard cavities were prepared on root surfaces. All root surfaces, excluding the cavities, were covered with nail polish. Root canals were prepared using the Easy RaCe rotary system. The teeth were randomly divided into 3 experimental groups filled with calcium hydroxide pastes: (Group 1) Sure-Paste, (Group 2) Meta-Paste, and (Group 3) Multi-Cal. The control group had 2 samples. Teeth were then placed in 10 mL of normal saline. Environmental pH values were measured at 1 h, 24 h, 48 h, and 1 week. Statistical evaluations of the results were performed via the ANOVA and Tukey tests.
  
  
  RESULTS
  Results demonstrated that groups 3 and 1 showed a significant statistical difference (P<.001) with the pH being greater in group 3. There was no significant difference between groups 2 and 3 (P>.05). Intracanal placement of Multi-Cal compared with that of Sure-Paste and Meta-Paste resulted in a higher pH in simulated root resorption defects.
  
  
  CONCLUSIONS
  In cases, like apexification, that need longer pH changes and higher disinfecting qualities, it might be better to use Multi-Cal, and for short-time use as disinfectant medicament Multi-Cal and Meta-Paste are equally effective.
authors: Dental Material Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IRAN.
authors: Maryam
authors: M
authors: Javidi
authors: Mina
authors: M
authors: Zarei
authors: Farzaneh
authors: F
authors: Afkhami
authors: Leila Mokhtari Amir
authors: LM
authors: Majdi
keywords: Calcium hydroxide; intracanal dressings; pH; root surface defects