Chitosan-Based Biomaterial, Calcium Hydroxide and Chlorhexidine for Potential Use as Intracanal Medication

Comparative evaluation of antimicrobial efficacy of different combinations of calcium hydroxide against Enterococcus faecalis

BACKGROUND

The study aims to compare the synergistic antibacterial efficacy of different combinations of calcium hydroxide as an intracanal medicament against E. faecalis.

MATERIAL AND METHODS

The current study included four hundred extracted human permanent mandibular premolar teeth. After complete chemo-mechanical preparation, the middle third of the root was sectioned using a rotary diamond disc and a total of 400 samples were obtained. The specimens were inoculated with E. faecalis for 21 days. After that, specimens were divided into five groups (n = 80) based on materials used for the disinfection of samples: Group I, calcium hydroxide alone; Group II, calcium hydroxide + 2% chlorhexidine gel; Group III, calcium hydroxide + 2% chitosan gel; Group IV, calcium hydroxide + 0.02% silver nanoparticle gel; Group V, calcium hydroxide + Bioactive glass S53P4. Dentin shavings from the apical third were obtained from the inner third of dentin were obtained using gates glidden no.1 to the apical depth, followed by no.2, 3, 4 and 5 analyzed for E. faecalis using the culture method. One-way analysis of variance (ANOVA) was used for data analysis, followed by post-hoc Tukey's test for multiple comparisons of means to check the difference in bacterial inhibition between the groups.

RESULTS

ANOVA results revealed a significant reduction of bacterial counts in all the groups compared (p < 0.001). Intergroup comparison showed maximum bacterial reduction (p < 0.001) with calcium hydroxide + bioactive glass S53P4 compared with other groups.

CONCLUSION

Synergistic effect of calcium hydroxide showed better bacterial reduction compared to calcium hydroxide alone. Among the combinations evaluated, calcium hydroxide with bioactive glass, found to be most effective compared to other groups.

Comparative evaluation of calcium ion release, pH change, and dentinal tubule penetration of four different formulations of calcium hydroxide-based intracanal medicaments - An in vitro study

Aim

The aim of the study was to evaluate and compare the release of calcium ion, pH change, and dentinal penetration depth of four different formulations of calcium hydroxide-based intracanal medicaments.

Materials and Methods

Eighty mandibular single-rooted premolar teeth were divided into four groups (n = 20): Group 1 - calcium hydroxide (CH) + distilled water (DW), Group 2 - nanocalcium hydroxide + DW, Group 3 - calcium hydroxide + chitosan, and Group 4 - calcium hydroxide + 2% chlorhexidine gluconate. Biomechanical preparation was done till the F2 rotary ProTaper system and intracanal medicaments were placed. Calcium ions and pH were assessed at 24 h, 7 days, 15 days, and 30 days using an ultraviolet spectrophotometer and pH meter, respectively. The evaluation of tubule penetration was scanned under a field emission scanning electron microscope.

Results

A significant difference was seen in calcium ion release and pH change among the four groups at 24 h, 7 days, 15 days, and 30 days as well as depth of dentinal penetration.

Conclusion

Calcium hydroxide mixed with 2% chlorhexidine gel showed alkaline pH and the highest calcium ion release as well as significant dentinal tubule penetration among all the four groups under observation. Both combinations can enhance antimicrobial effectiveness as intracanal medicaments. Further clinical study should be carried out to optimize its use as an alternative treatment modality.

How Adding Chlorhexidine or Metallic Nanoparticles Affects the Antimicrobial Performance of Calcium Hydroxide Paste as an Intracanal Medication: An In Vitro Study

The aim of our study was to explore the potential value of metallic (Ag, Cu, and Zn) salts, polymer/metallic nanoparticles, and chlorhexidine (CHX) for improving the antimicrobial activity of calcium hydroxide (CH) against E. faecalis and C. albicans, associated with persistent endodontic infections. A first screening was performed by determining minimum inhibitory/bactericidal concentrations (MIC/MBC). Antimicrobial activity of the CH paste mixed with metallic salts, chitosan or cyclodextrin polymer metallic nanoparticles was compared to the antimicrobial activity of CH paste alone and CH + CHX using a time-kill kinetics assay. The effect of the antimicrobials on the rheological and the key mechanical properties were also examined. Copper and zinc were discarded because of their MIC/MBC values and silver because of its kill time curve profile. Except for a slower setting time after 24 h and a higher weight loss after 1 week of incubation, the mechanical behavior of the CH paste was unaffected by the addition of CHX. Polymeric/metallic nanoparticles failed to potentiate the antimicrobial effect of CH. By contrast, CHX increased this effect and thus could help eradicate E. faecalis associated with persistent root canal infections without altering the desired key physical properties of the CH paste.