Antimicrobial effect and pH of chlorhexidine gel and calcium hydroxide alone and associated with other materials

Abstract

The purposes of this study were to evaluate the effectiveness of 2% chlorhexidine (CHX) gluconate gel, calcium hydroxide [Ca(OH) 2 ] and their combination with iodoform and zinc oxide powder as intracanal medications against select microorganisms, and to measure the pH changes caused by these medications. Antimicrobial activity was determined by the agar diffusion method. The zones of growth inhibition were measured and the results were analyzed statistically by Kruskal-Wallis test (p<0.05). The pH of the pastes was measured right after preparation, after 24 h and 1 week later. The largest mean zones of microbial inhibition were produced by 2% CHX gel, followed by Ca(OH) 2 + 2% CHX gel + iodoform, Ca(OH) 2 + 2% CHX gel, Ca(OH) 2 + 2% CHX gel + zinc oxide, and Ca(OH) 2 + water. The mean pH of all medications stayed above 12.0 during the whole experiment, except for CHX gel (pH=7.0). The results of this study showed that all medications had antimicrobial activity, but the most effective against the tested microorganisms were 2% CHX gel, followed by its combination with Ca(OH) 2 and iodoform.

Antimicrobial Activity and Biocompatibility of the Psidium cattleianum Extracts for Endodontic Purposes

“…CHX has a reasonably wide range of activity against aerobic and anaerobic bacteria, as well as Candida species. Several studies have reported a better antimicrobial activity for CHX when used as an endodontic dressing, compared with CH and the association of CHX and CH (7)(8)(9). Although CHX is also a potent antimicrobial irrigant, its capacity of tissue dissolution is reduced and when in contact with a common endodontic irrigant, sodium hypochlorite, it results in a "potentially toxic precipitate" (10).…”

Intracanal dressing paste composed by calcium hydroxide, chlorhexidine and zinc oxide for the treatment of immature and mature traumatized teeth

“…Endodontic filling with gutta-percha and sealer does not dissolve, differently from what occurs with this intracanal dressing paste, since it may dissolve at the same time as it comes into contact with the periapical tissues. This paste also demonstrated antimicrobial properties, and maintained alkaline pH for one week 25 . It is likely that after some weeks, only zinc oxide was present, since Ca(OH) 2 should have undergone complete dissolution 14 .…”

“…In this study, 2% chlorhexidine gel was used as auxiliary chemical substance. It was demonstrated that 2% chlorhexidine gel has excellent antimicrobial activity and is more biocompatible than sodium hypochlorite 25 .…”

Gelatin as a Chlorhexidine Digluconate Immobilizing Agent

“…There is another endothermic event smaller, which took place around 186°C. This is due to the fusion of chlorhexidine [17]. Pure gelatin has an endothermic peak ranging from 46°C to 160°C.…”