Antimicrobial evaluation of Ca(OH)₂ with different vehicles in dentinal tubules

Objectives: The purpose of this study was to evaluate the antimicrobial activity of calcium hydroxide (Ca(OH)₂) mixed with different vehicles in infected dentinal tubules in vitro. Methods: Ca(OH)₂ mixed with sterile 0.9% sodium chloride solution, Ca(OH)₂ mixed with propylene glycol, and Ca(OH)₂ mixed with 30% glycerin and camphorated phenol were tested. The crowns and apices of the teeth were resected to produce uniform 6-mm-long specimens and sterilized by autoclaving. Specimens were infected with Streptococcus mutans (NCTC Ingbritt) for 24 h, and then completely filled with calcium hydroxide pastes. At the intervals of 3 and 7 days, dressings were removed and dentin chips were collected and incubated in BHI for 72 h to observe the growth and multiplication of the microorganism, respectively. Results: One-way analysis of variance was performed to test the differences between groups. And Tamhane's T₂ was used for multiple comparison. In this study, Ca(OH)₂ with propylene glycol demonstrated the best antimicrobial activity when the paste was placed for 3 days; and there were no differences between the three vehicles when the pastes were placed for 7 days. Conclusions: Ca(OH)₂ with propylene glycol is more effective in the elimination of S. mutans from dentinal tubules in vitro.