Antimicrobial Substantivity of Bovine Root Dentin Exposed to Different Chlorhexidine Delivery Vehicles

Abstract

Root canal dentin acquires antimicrobial substantivity after exposure to chlorhexidine gluconate (CHX) for 1 wk. Therefore development of a vehicle for delivery of CHX as an intracanal medication is desirable. This in vitro study assessed the efficacy of two CHX delivery vehicles, a controlled-release device and a gel, to affect antimicrobial substantivity of bovine root dentin. Sixty bovine incisor root specimens were prepared with standardized length (10 mm) and canal diameter (3.3 mm), and coated externally with nail polish. Specimens were divided into four equal groups and their canals medicated for 7 days with either: (i) an experimental controlled-release device containing 25% CHX that was immersed in sterile saline; (ii) 2% CHX gel; or (iii) Ca(OH)2 paste. Sterile saline was used as the positive control. After medication, the canals of the specimens were inoculated with Enterococcus faecalis for 21 days. Root canal dentin samples ranging in depth from 0.1 to 0.45 mm were then obtained using sterile round burs of ascending diameter. Each dentin sample was placed in a separate test tube containing Brain Heart Infusion broth and incubated for 24 h. The optical density (OD) of the broth was then measured spectrophotometrically at 540 nm. The positive control showed significantly higher mean OD values (one-way ANOVA and Tukey's Studentized Range Test; p < 0.001) than the three test groups. The CHX controlled-release device group showed significantly lower OD values than the Ca(OH)2 group; however only at dentin depths up to 0.2 mm. In contrast, the CHX gel group consistently showed significantly lower OD values than both the CHX controlled-release device and Ca(OH)2 groups. These results suggest that bovine root canals medicated with 2% CHX gel for 7 days acquire antimicrobial properties for at least 21 days.

Microbiological Analysis of Teeth with Chronic Apical Periodontitis and the Outcome of Treatment by Gutta Percha Points Impregnated with Either Calcium Hydroxide or Chlorhexidine as Intra Canal Medicament

“…In these devises, CHX was contained in a polymer sheath that when placed in a liquid environment gradually dissolved and released CHX. Those devises were the predecessors for the CHX points, where some of them presented satisfied results while others failed [34,35]. In the present study CHX, points displayed a significant better antibacterial effect than Ca(OH) 2 points.…”

Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis

“…62 Chlorhexidine exhibits substantivity to dentin and consequently may present residual antimicrobial effects for days to weeks and help prevent root canal reinfection. 52,[63][64][65][66][67][68][69] This seems to be an important advantage over NaOCl. Nevertheless, one important disadvantage of chlorhexidine is that it lacks tissue-dissolving ability, which is one of the obvious benefits of NaOCl.…”

A scanning electron microscopic evaluation of different root canal irrigation regimens

“…When it is associated with Cetavlon (EDTAC), it exhibits lower surface tension, better efficiency and quicker action in root canal therapy than the original formulation 11 . Several researchers have pointed out the potential of chlorhexidine gluconate as a safe and effective antibacterial medicament for use in endodontic therapy 1,17 . Chlorhexidine gluconate, a broad-spectrum antimicrobial agent that can be successfully used either as an irrigant or an intracanal medicament 15 , disinfects the dentinal tubules and adsorbs onto the root canal dentin walls.…”

“…Chlorhexidine gluconate, a broad-spectrum antimicrobial agent that can be successfully used either as an irrigant or an intracanal medicament 15 , disinfects the dentinal tubules and adsorbs onto the root canal dentin walls. Studies have disclosed that, as result of such property, root dentin treated with chlorhexidine seems to acquire antimicrobial substantivity 17,24 . Moreover, chlorhexidine is reported to be relatively nontoxic to periapical tissues 16 and therefore may be well indicated as a reliable option for patients allergic to sodium hypochlorite 13 .…”