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One critical issue that impairs the therapeutic effects of antimicrobial photodynamic therapy (aPDT) in root canal disinfection is the insufficient penetration of photosensitizer into dentinal tubules. Therefore, this study aimed to compare the treatments in enhancing photosensitizers' penetrability for aPDT in root canal therapy.Thirty premolars with a single root canal were randomly divided into three groups (n = 10), using Methylene blue (MB) as a photosensitizer and treated with different approaches: sonic-assisted diffusing group, ultrasonic-assisted diffusing group and the control without treatment. All specimens were observed by stereomicroscope to measure the penetration depth of MB into dentinal tubules.Both sonic and ultrasonic treatments substantially improved the penetrability of MB. The former achieved a deeper penetration depth than the latter did in the same region of root (P0.05). Regarding the dye penetration depths at different root regions, the control group showed a declining trend from coronal to apical. In contrast, the penetration depths of sonic and ultrasonic-assisted diffusing groups from highest to lowest were middlecoronalapical (P0.05).This study showed that both sonic and ultrasonic treatments remarkably promoted MB's penetration depth into dentinal tubules. Maximum penetration was achieved when treated with a sonic approach.

Various antimicrobial modalities have been proposed to treat peri-implantitis but resulted in limited outcomes. The aim of this in vitro study was to evaluate the disinfection efficacy of combined application of chlorhexidine digluconate (CHX) and antimicrobial photodynamic therapy (aPDT) of titanium surfaces previously contaminated with Porphyromonas gingivalis biofilm. P. gingivalis biofilms were grown on 32 polished and 32 sandblasted large-grit acid-etched (SLA) titanium surfaces. Titanium disks were allocated into four groups as follows: (1) immersed in phosphate-buffered saline (PBS), (2) immersed in 0.2% CHX, (3) application of aPDT and (4) immersed in 0.2% CHX and subsequent aPDT. Residual bacteria were determined by microbial culture analysis and by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) imaging. Combination protocol (CHX+ aPDT) was the most effective in eradicating P. gingivalis (P 0.05) on both polished and SLA surfaces. There was no significant difference in the number of remaining P. gingivalis between polished titanium disks and the SLA ones in four groups (P 0.05). Under the limitation of this study, combined technique of preceding application of CHX and subsequent aPDT was shown to be an efficient method in reducing P. gingivalis numbers in both polished and SLA titanium surfaces.

Candida albicans (C.albicans) is the primary pathogen of denture biofilm. Moreover, it could establish a cross-kingdom relationship with bacteria to enhance its virulence and resistance to antifungal drugs. This study aimed to investigate the efficacy of antimicrobial photodynamic therapy (aPDT) in combination with hydrogen peroxide (HC.albicans and S.mutans were grown on PMMA disk for 48 h to form biofilm and received different treatments. The treatments included:1) phosphate-buffered saline (PBS) group,2) 100 mM HThere was no significant difference between PBS group and HPretreatment with H

This study was to test the hypothesis that root canal pretreated with photodynamic therapy (PDT) would promote stem cells from the apical papilla (SCAP) adhesion, proliferation and differentiation without affecting smear layer removal and microhardness of root canal. Standardized root canals were randomized into four groups (n = 30/group): (1) sodium hypochlorite(NaOCl) group, (2) NaOCl + ethylene diaminetetraacetic acid (EDTA) group, (3) NaOCl + PDT group, (4) NaOCl + EDTA + PDT group. After treatments, smear layer removal and microhardness of root canal were evaluated. SCAP with hydroxyapatite-based scaffolds were seeded into root canals for 7 days. SCAP adhesion was observed by scanning electron microscope (SEM), and viable cells were calculated by CellTiter-Glo Luminescent kit. Platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) expression of SCAP were evaluated by Quantitative Reverse Transcriptase-Polymerase Chain Reaction. There was no significant difference in the smear layer removal and microhardness of root dentin between the groups with and without PDT treatment (P > 0.05). SCAP with elongated cytoplasmic processes and cell-cell contact were observed on the dentin surfaces treated with PDT. Elevated cell viability, PDGF and VEGF expression were found in root canal treated with PDT (P < 0.05). Under the experimental conditions, PDT could provide positive microenvironment for SCAP growth.

Background S. aureus biofilm plays a predominant role in the establishment and development of peri-implantitis. It is suggested to combine different modalities as peri-implantitis treatment. The aim of this study was to evaluate the disinfection efficacy of combined application of antiseptics with PDT on Staphylococcus aureus (S. aureus) biofilm formed on titanium(Ti) disks with different surface roughness. Methods S. aureus biofilm was incubated on polished and sandblasted large-grit acid-etched (SLA) Ti surfaces for 48 h. 72 contaminated Ti disks (36 polished, 36 SLA) were randomly divided into 6 different groups as follows: (a) PBS, (b) 0.2% chlorhexidine digluconate (CHX), (c) 3% hydrogen peroxide (H2O2), (d) PDT, (e) 0.2% CHX + PDT, and (f) 3% H2O2+PDT. Colony forming unit (CFU) was measured to determine antimicrobial effects. Biofilm structure was assessed using scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM). Results All disinfection methods significantly reduced bacteria amounts compared to control group on both polished and SLA Ti surfaces (P Conclusion The combination of CHX or H2O2 administration with PDT was more effective in eradicating S. aureus on both polished and SLA Ti disks in comparison with either treatment alone, suggesting that combined usage of antiseptics with PDT could be a more efficient method for the treatment of peri-implantitis.

Concentration of sodium hypochlorite (NaOCl) is positively correlated with its effectiveness in root canal disinfection but negatively correlated with its biocompatibility. The objective of this in vitro study was to compare the bactericidal effects among ultrasonic irrigation with different concentration of NaOCl alone or together with photodynamic treatment (PDT) against Enterococcus faecalis (E. faecalis) in infected root canals. One hundred and twenty bovine root canals contaminated with E. faecalis were randomly distributed into 12 groups treated with different disinfection methods: PDT, ultrasonic irrigation with NaOCl at different concentrations (0.5%, 1.0%, 2.0%, 2.5% and 5.25%), and ultrasonic irrigation with NaOCl at different concentrations plus PDT. Data of microorganism load were collected before and after disinfection and analyzed by one-way ANOVA and LSD tests. Significantly enhanced antibacterial effects were noticed in groups treated by PDT plus 2.0% or 2.5% NaOCl irrigation (P 0.05). No statistical differences existed in bactericidal efficacy among groups of PDT plus ultrasonic irrigation with 2.0%, 2.5% or 5.25% NaOCl, and ultrasonic irrigation with 5.25% NaOCl alone (P 0.05). Our study confirmed the feasibility to reduce the concentration of NaOCl to a safer level while maintaining its antibacterial efficiency through synergistic effect of PDT with NaOCl ultrasonic irrigation.

Enterococcus faecalis poses a challenge to the efficacy of traditional root canal disinfection methods. This study was aimed to establish a synergistic root canal disinfection strategy combining ultrasonic irrigation with photodynamic therapy (PDT) together and to test its antibacterial efficacy against E. faecalis. Twenty-seven bovine root canals infected with E. faecalis were randomly divided into three groups and treated with different disinfection methods as follows: ultrasonic irrigation with 2.5% NaOCl, methylene blue (MB)-mediated PDT, or combined ultrasonic irrigation and PDT as described above. Quantification of E. faecalis was performed on the root canals before and immediately after the disinfection treatment. Residual bacteria were determined by counting colony-forming units. Samples were randomly selected from the three groups, and the morphology of residual bacteria inside the dentinal tubules was studied by scanning electron microscopy. The number of surviving E. faecalis in the group treated with the combination method was significantly lower (P