Antibacterial effect of nano-chlorhexidine on Enterococcus faecalis biofilm in root canal system: An in vitro study.

Background: A new method to improve the properties of the materials is nano-encapsulation, which improves the biological properties, antibacterial activity along with reduction of toxicity. Due to the spread of nano-knowledge, the present study was performed to evaluate the antibacterial effect of nano-chlorhexidine (CHX) on Enterococcus faecalis biofilm in the root canal system. Materials and Methods: In this in vitro experimental study, 55 matured single-root mandibular premolars were decoronated and the canals were prepared by single length method up to #F3 ProTaper Universal system. Five teeth were selected as negative control. Then, the teeth were randomly divided into three experimental groups (n = 15) and a positive control group (n = 5). The experimental groups were irrigated with 2% nano- CHX gel, 2% CHX solution, and 5.25% sodium hypochlorite (NaOCl), respectively. Finally, the number of colonies was counted. Kruskal-Wallis test was used to compare the number of colonies among groups. The level of significance was set at P < 0.05. Results: The mean number of colonies in the groups of nano-CHX, NaOCl, CHX, and positive control were obtained as 17.73 ± 18.69, 35.53 ± 36.42, 38.8 ± 31.8, and 96.8 ± 22.52, respectively. There was a significant decrease in the number of colonies in all the experimental groups compared to the control group (P < 0.05). However, difference in the number of colonies among these three groups was not significant (P > 0.05). Conclusion: The use of nano-CHX in removing E. faecalis biofilm from root canal is as effective as the use of CHX and NaOCl.

Evaluating the adhesion of human gingival fibroblasts and MG-63 osteoblast-like cells to activated PRP-coated membranes.

Regeneration of periodontal tissues is affected by the biological and morphological characteristics of the membrane surface. The current study evaluated the adhesion of human gingival fibroblasts (HGF) and MG-63 osteoblast-like cells to Membranes, with and without activated PRP. The line of human gingival fibroblast cells and MG-63 osteoblast-like cells were first prepared and cultured on three types of membranes, including Jason, CenoMembrane and TXT-200 in three groups (FBS 10%, FBS 0.5% and activated PRP). Cell viability was investigated by MTT assay and electron microscopy (SEM) was used to evaluate the cell morphology and adhesion on these membranes after 24 and 72 h. Two-way ANOVA was carried out at the significance level of 0.05. The highest adhesion in the 10% FBS group for HGF and The MG-63 osteoblast-like cells was observed to the Jason membrane during 24 h and 72 h (p < 0.05). However, there were no significant differences among the three membranes in PRP and FBS groups for HGF during 24 h and for MG-63 cells during 72 h (p > 0.05). Activated PRP had a positive effect on the viability and adhesion of both human gingival fibroblasts and osteoblast-like cells as compared to the FBS 0.5% group, but these effects were not as 10% FBS group. The results also showed that Jason membrane had the highest amount of cell viability and adhesion.

Effect of one and two sessions of antimicrobial photodynamic therapy on clinical and microbial outcomes of non-surgical management of chronic periodontitis: A clinical study.

Background: This study aimed to compare the effect of one and two sessions of antimicrobial photodynamic therapy (aPDT) as an adjunct to scaling and root planing (SRP) on clinical and microbial parameters in patients with chronic periodontitis. Methods: This study was conducted on 20 patients. The dental quadrants of patients were randomly assigned to SRP at baseline (group 1), SRP at baseline and one month (group 2), SRP plus aPDT at baseline (group 3) and SRP plus aPDT at baseline and one month (group 4). Probing depth (PD), clinical attachment level (CAL) gain, and bleeding on probing (BoP) were measured at baseline, and one and three months later. F. nucleatum counts were determined by PCR. ANOVA was used for the comparison of these variables between the groups. Results: In all the groups, PD reduction and CAL gain increased significantly at 1- and 3-month intervals compared to baseline (P=0.001). At three months, the difference in PD between groups 1 and 3 was statistically significant (P=0.014). CAL gain between groups 2 and 4 at one month (P=0.016) and three months (P=0.001) wasstatistically significant. Reduction in F. nucleatum counts was not significant between the four study groups (P>0.05). Conclusion: A combination of two sessions of aPDT and SRP could improve CAL gain; however, further long-term studies are necessary in this regard.