Photo-activated elimination of Aggregatibacter actinomycetemcomitans in planktonic culture: Comparison of photodynamic therapy versus photothermal therapy method

Bactericidal Effect of Different Photochemical-Based Therapy Options on Implant Surfaces-An In Vitro Study

Objectives: Photochemical systems are frequently recommended as an adjuvant treatment option in peri-implantitis therapy. The aim of the present study was to evaluate the efficacy of these treatment options, as well as a novel curcumin-based option, in a biofilm model on implants. Methods: Eighty dental implants were inoculated with an artificial biofilm of periodontal pathogens and placed in peri-implant pocket models. The following groups were analyzed: I, photodynamic therapy (PDT); II, PDT dye; III, curcumin/DMSO + laser; IV, curcumin/DMSO only; V, dimethyl sulfoxide (DMSO) only; VI, photothermal therapy (PTT); VII, PTT dye; VIII, control. After treatment, remaining bacterial loads were assessed microbiologically using quantitative real-time polymerase chain reaction analysis. Results: The PDT, PTT, and DMSO treatment methods were associated with statistically significant (p < 0.05) improvements in germ reduction in comparison with the other methods and the untreated control group. The mean percentage reductions were as follows: I (PDT) 93.9%, II (PDT dye) 62.9%, III (curcumin/DMSO + laser) 74.8%, IV (curcumin/DMSO only) 67.9%, V (DMSO) 89.4%, VI (PTT) 86.8%, and VII (PTT dye) 66.3%. Conclusions: The commercially available PDT and PTT adjuvant treatment systems were associated with the largest statistically significant reduction in periopathogenic bacteria on implant surfaces. However, activation with laser light at a suitable wavelength is necessary to achieve the bactericidal effects. The use of curcumin as a photosensitizer for 445 nm laser irradiation did not lead to any improvement in antibacterial efficacy in comparison with rinsing with DMSO solution alone.

Evaluation the antibacterial efficacy of sodium hypochlorite in combination with two different photodynamic therapy protocols against Enterococcus Faecalis in Infected root canals: An in-vitro experiment

BACKGROUND

Photodynamic therapy (PDT) is an antimicrobial approach that can be used as an adjunctive safe technique for root canal disinfection. In this study, we aimed to evaluate the antibacterial efficacy of PDT with indocyanine green and toluidine blue in combination with sodium hypochlorite (NaOCl) in compared with NaOCl alone against Enterococcus faecalis in infected root canals.

METHODS

Sixty five root canals of sound human premolars were collected. First, the teeth were sterilized, then 60 root canals were inoculated with the E. faecalis, and 5 samples served as negative control remained uncontaminated. The contaminated root canals were randomly assigned into 4 experimental groups (n=15): (1) NaOCl, (2) NaOCl+ PDT-1 (toluidine blue + 630nm LED), (3) NaOCl+ PDT-2 (indocyanine green + 808nm diode laser), and (4): positive control (no treatment). Then, the colony-forming units (CFU/mL) of E. faecalis were calculated in all the groups. Moreover, 5 samples from each group were examined under a scanning electron microscope. The data were analyzed by independent T-test and the Mann-Whitney U test at the significance level of 0.05.

RESULTS

The CFU count was significantly lower in the indocyanine green-PDT group in comparison with other groups (p˂0.05). The mean of CFU in the positive control group was significantly higher than the other groups (p˂0.05). No significant difference was detected between NaOCl and toluidine blue -PDT group (p=1.00).

CONCLUSION

Indocyanine green- PDT improved the antibacterial effects of NaOCl against E. faecalis, while toluidine blue - mediated PDT had no significant additional effect on NaOCl.

The Effectiveness of Laser Applications and Photodynamic Therapy on Relevant Periodontal Pathogens (Aggregatibacter actinomycetemcomitans) Associated with Immunomodulating Anti-rheumatic Drugs

Considering the current context of the increasing resistance of bacterial species to antibiotics and other antimicrobial agents, a major objective is to develop other antimicrobial approaches, which would be able to inactivate pathogens with considerable effectiveness. Two such methods are photodynamic disinfection therapy and laser irradiation. In view of the immunocompromised status of some patients under immunosuppressive therapy and potential drug interactions that can be established between systemic antimicrobial agents, the research of local, minimally invasive methods of inactivating periodontal pathogens in the context of these systemic therapies with modifying drugs of the immune response is justified. This in vitro study evaluated the antimicrobial action of a diode laser, wavelength 940 nm, and photodisinfection therapy at 670 nm (photosensitizer, 3,7 dimethyl phenothiazine chloride) on a type strain of Aggregatibacter actinomycetemcomitans, a known periodontal pathogen, in the presence and absence of active substances used in autoimmune disease therapy (Etanercept, Infliximab, Metothrexate). The association of a conventional antirheumatic drug with anti-TNF-α therapy determined a significantly greater inhibition of the strain of A. actinomycetemcomitans compared to monotherapy, in vitro. Photodisinfection caused a significant reduction in bacterial burden after a 30 s exposure in vitro, regardless of the pharmaceutical associations of biological and conventional disease-modifying antirheumatic drugs (DMARDs). Irradiation with a diode laser for 30 s at a power of 5 W caused a greater reduction compared to irradiation with 1 W. The application of laser and photodisinfection induced a significant reduction in Aggregatibacter actinomycetemcomitans in vitro and could be considered important adjunctive measures for the eradication of this oral pathogen in the context of immunomodulating therapy.

The Effects of 810 nm Diode Laser and Indocyanine Green on Periodontal Parameters and HbA1c in Patients with Periodontitis and Type II Diabetes Mellitus: A Randomized Controlled Study

The aim of this study was to investigate the effects of adjunctive periodontal therapy of 5 mg/mL indocyanine green irradiation by an 810 nm diode laser (aPDT), supplementary to scaling and root planing (SRP) in patients with periodontitis and type II diabetes mellitus (DM) compared to the SRP alone, on periodontal clinical parameters and glycated hemoglobin A1c (HbA1c). The study was conducted on 49 subjects with type II DM and periodontitis, divided into two groups: the SRP group (n = 25), who followed SRP alone, and the SRP + aPDT group (n = 24), who followed SRP and four weekly sessions of indocyanine green irradiation by an 810 nm diode laser. Plaque Index (PI), Bleeding on Probing Index (BOP), probing depth (PD), clinical attachment loss (CAL) and HbA1c were investigated at baseline and after 6 months. At 6 months, both SRP alone and SRP + aPDT generated significant reductions in all the investigated parameters; SRP + aPDT produced more significant reductions for BOP, PD and CAL (p < 0.001) but not for PI and HbA1c, than SRP alone. aPDT with indocyanine green therapy was well tolerated, with two subjects reporting slight discomfort. Therefore, aPDT with indocyanine green might represent a good adjunctive periodontal treatment option for SRP in patients with type II DM and periodontitis.

Antimicrobial photothermal therapy using diode laser with indocyanine green on Streptococcus gordonii biofilm attached to zirconia surface

PURPOSE

The purpose of this study was to evaluate the antimicrobial effects of photothermal therapy using indocyanine green (ICG) and an 810-nm infrared diode laser on Streptococcus gordonii biofilm attached to zirconia surfaces in vitro.

METHODS

A biofilm was formed using the static method on zirconia disks placed in a 24-well plate. The biofilms were subdivided into the following six treatment groups: control, commercial photodynamic therapy (PDT), chlorhexidine gluconate (CHX), laser only (L, 810-nm infrared diode), ICG, and laser with ICG (PTT). After treatment, each disk was agitated and the solution with detached bacteria was spread directly on a blood agar plate. Cells were cultured under anaerobic conditions and colony-forming units were counted. Confocal laser-scanning microscopy was used to assess the survival according to the height of the biofilm.

RESULTS

The PTT, PDT, and CHX groups showed a significant reduction in S. gordonii viability (p<0.05), while the L and ICG groups showed no significant difference compared to the control group (p=0.32, p=0.97; respectively). In confocal laser-scanning microscopy images, the PTT, PDT, and CHX groups presented most of the dead bacteria in both the upper and lower levels of biofilm.

CONCLUSION

Within the limitations of this in vitro study, PTT with ICG was effective in significantly reducing the viability of S. gordonii bacteria on zirconia. Further studies are needed to establish a standardized PTT protocol to treat peri-implant diseases.

The ever-changing landscape in modern dentistry therapeutics - Enhancing the emptying quiver of the periodontist

Introduction/Objectives

Periodontitis comprises of a wide range of inflammatory conditions of the gums leading to soft tissue damage and attachment loss. The initiation of periodontitis constitutes a rather complex disease pathogenesis which is based on pathogenic shifts of the oral microbiota combined with the host-microbiome interactions. The severity of the periodontitis is multifactorial depending on genetic, environmental, as well as host immunity factors.

Data and sources

To make an inclusive analysis on the periodontitis therapeutics, reading of the recent relevant literature was carried out using the MEDLINE/PubMed database, Google Scholar and the NIH public online database for clinical trials (http://www.clinicaltrials.gov).

Conclusions

Tackling the inflammation associated periodontal defects can be succeeded with conventional therapy or resective and regenerative treatment. To date, the mechanical removal of the supragingival and subgingival biofilm is considered the “gold standard” of periodontal therapy in combination with the use of antibacterial compounds. The antimicrobial resistance phenomenon tends to turn all the currently applied antibacterials into “endangered species”. Ongoing efforts through the conduct of clinical trials should be focused on understanding the advantages of modern approaches in comparison to traditional therapies.

Impact of thermal photodynamic disinfection on root dentin temperature in vitro

BACKGROUND

Thermal photodynamic disinfection procedures have been proposed for adjunctive endodontic treatment. This study assessed photothermal disinfection relative to root dentin temperature and the thermal effects of simulated periodontal blood flow.

METHODS

Thirty freshly extracted human single-rooted teeth were prepared endodontically using a 45/.02 master apical file. The root surfaces were coated with wax and covered with thermoforming sheets, leaving a circumferential space of 0.25 mm after wax removal. The sheets were perforated to allow fluid circulation through the simulated periodontal space. Irradiation was performed in two groups of 30: I, 810 nm laser (1.5 W, continuous wave), 4 × 5 s; II, photothermal group: indocyanine green and 810 nm laser (200 mW, continuous wave), 20 s. Thermographic measurements were performed at different water flow rates (6, 2.6, 0 mL/min) with a baseline temperature of 37 °C. Nonparametric statistical analysis was performed (Wilcoxon).

RESULTS

The highest temperature change (median 7.52 °C, range 0.82-18.32 °C) was with 810 nm laser irradiation in group I, without any simulated blood flow. Fluid circulation resulted in a significant reduction in temperature changes in this group (median 2.14 °C, range 0.37-9.83 °C; p  < 0.05). The lowest temperature changes were in the photothermal group with a water flow rate of 6 mL/min (median 0.79 °C, range 0.00-3.88 °C; p < 0.05).

CONCLUSION

Photothermal disinfection of root canals can increase root canal dentin temperatures, but periodontal fluid circulation has a cooling effect on the outer root surface, reducing the risk of potential thermal injury to periodontal tissue.

Effect of photobiomodulation on post-operative symptoms in teeth with asymptomatic apical periodontitis treated with foraminal enlargement: A randomized clinical trial

AIM

To assess the efficacy of photobiomodulation in reducing post-operative symptoms and use of analgesics in teeth with asymptomatic apical periodontitis treated with foraminal enlargement in a single visit.

METHODOLOGY

This prospective double-blind, controlled, superiority, randomized clinical trial enrolled 70 patients requiring root canal treatment of one single-rooted tooth with asymptomatic apical periodontitis. The participants were randomized into one of the following two groups: 35 patients in the control group (C.G) - root canal treatment with foraminal enlargement, without any additional treatment and 35 patients in the photobiomodulation group (PBM.G) - root canal treatment with foraminal enlargement associated with photobiomodulation (antimicrobial photodynamic therapy and low-level laser therapy). The outcome variables were post-operative pain, tenderness, oedema and the use of analgesics. Pain intensity was measured using a visual analogue scale (recorded every day for 7 days, then the 14th and 30th days after root canal treatment). Facial oedema was assessed subjectively by two independent evaluators using photographs taken by one of the researchers at 48 h, 72 h and 7 days after the procedures. Data were tabulated and analysed using the Mann-Whitney U, Chi-Square, Fisher`s Exact, Student T and Ordinal Logistic Regression by Generalized Estimating Equations tests in SPSS software.

RESULTS

There were no significant differences in post-operative pain and tenderness between the groups at any observation period (p > .05). Photobiomodulation (beta = -0.77 / p = .01), time (beta = -0.23 / p < .01), and male gender (beta = -1.20 / p < .01) were associated with decreased post-operative pain. Only time (beta: -0.10; p < .01) and male gender (beta: -1.04; p < .01) were associated with decreased tenderness. For oedema and use of analgesics, there was no difference between the groups (p > .05).

CONCLUSIONS

Photobiomodulation had no significant effect on post-operative pain, tenderness, oedema and the use of analgesics after root canal treatment with foraminal enlargement, in single-rooted teeth treated in a single visit. Register of Clinical Trials: NCT03704857. Research Ethics Committee: no 2.353.996 / CAAE 74185417.9.0000.5626.

Applications of Lasers in Refractory Periodontitis: A Narrative Review

OBJECTIVE

The purpose of the study is to evaluate the various lasers in dentistry and to investigate if it can be used for treatment of refractory periodontitis.

METHODS

The study followed partially the PRISMA guidelines as it is a narrative review. A number of articles were selected from a period of 1980 to 2020 from databases, PubMed, PubMed central, Cochrane and Scopus. Articles related to the effects of lasers on periodontitis both refractory and aggressive were investigated.

RESULTS

After reviewing the literature, 70 articles were found, related to application of lasers in periodontal diseases. Out of the 70, 11 articles pertained to the effect of laser for the treatment of Refractory and inflammatory periodontitis. 5 articles related to experimental animal models, one pertaining to in-vitro and six studies related to in-vivo in human cohorts.

DISCUSSION

It was found that lasers if used in controlled parameters by incorporating laser assisted treatment such as Photodynamic therapy and low level laser therapy can be of use as an adjunct therapy for treatment of refractory periodontitis. The use of different wavelengths in the initial and maintenance phase of periodontal disease plays a positive role. The presence of in-vitro and animal model studies is one of the limitation to this study. The available studies have shown marked reduction in inflammation and better clinical and microbiological parameters. The drawback of this study is the limited literature involving laser management for refractory periodontitis in human cohorts.

CONCLUSION

Different wavelengths of laser and choice of laser assisted periodontal treatment plays an important role in the overall progress and prognosis of periodontal disease activity.

Clinical outcomes of adjunctive indocyanine green-diode lasers therapy for treating refractory periodontitis: A randomized controlled trial with in vitro assessment

BACKGROUND/PURPOSE

It is still challengeable to treat periodontal pockets refractory to mechanical debridement. This study is to evaluate the potential of indocyanine green (ICG)-diode laser-based photothermal therapy (PTT) for solving this dilemma.

METHODS

Bone marrow-derived mesenchymal stem cells (BMSCs) and periodontal ligament cells (PDLCs) were incubated with phosphate-buffered saline, chlorhexidine, or ICG, non-irradiated or irradiated with 810-nm diode lasers, and the cell viability was evaluated. Patients with teeth refractory to mechanical periodontal debridement on different quadrants were recruited. At baseline (T0), all examined teeth received scaling and root planing, and those on the test quadrant (PTT group) received ICG-diode laser treatment. The outcome was evaluated using clinical parameters and cytokines in the gingival crevicular fluids at 4-6 weeks (T1) and 6 months (T2).

RESULTS

In ICG-treated cultures, the viability of BMSCs and PDLCs was recovered on day 4, and laser irradiation inhibited the metabolic activities of BMSCs. 22 patients with 30 control teeth and 35 PTT-treated teeth were examined. All examined teeth showed modest reductions in probing pocket depth (PPD), clinical attachment loss (CAL), bleeding upon probing (BOP), and plaque score at T1 and T2 and significant reductions in IL-1β and MMP-8 at T2. Compared with controls, BOP was reduced more prominently, IL-1β and MMP-8 were significantly lower, and reductions in PPD and CAL were slightly greater in the PTT group at T1 (0.05-0.19 mm).

CONCLUSION

ICG-diode laser-based PTT is compatible to periodontium and assists in faster resolution of gingival inflammation in periodontal pockets refractory to mechanical debridement.

Comparison of different laser-based photochemical systems for periodontal treatment

PURPOSE

The main aim in periodontitis treatment is to remove supragingival and subgingival biofilm. Mechanical treatment to eliminate pathogenic bacteria is limited by morphological conditions on the root surface. This study assessed the antibacterial effectiveness of different laser-based photochemical systems, particularly a novel curcumin-based option.

METHODS

Ninety-one titanium bars were inoculated with an artificial biofilm of common pathogenic periodontal bacteria and inserted into an artificial periodontal pocket model. The following groups (n = 13) were tested: 1, curcumin solution plus SLB laser irradiation (C + L; 445 nm, 0.6 W, 25% duty cycle, 100 Hz, 10 s); 2, curcumin solution (Cur); 3, dimethyl sulfoxide solution (DMSO); 4, SiroLaser Blue (SLB) - laser irradiation (445 nm, 0.6 W, 25% duty cycle, 100 Hz, 10 s); 5, antimicrobial photodynamic therapy (aPDT); 6, antimicrobial photothermal therapy (aPTT); 7, control. The samples were stored in Eppendorf tubes and analyzed microbiologically using quantitative real-time polymerase chain reaction (PCR). The main parameter for analyzing group differences was the total bacterial load. Statistical analysis was performed with nonparametric methods.

RESULTS

Statistically significant reductions in bacterial count were observed in all experimental groups (p < 0.05). The mean percentage reductions were as follows: SLB, 95.03%; aPDT, 83.91%; DMSO, 95.69%; C + L, 97.15%. No statistically significant differences in bacteria reduction were observed for laser alone (SLB), DMSO, or curcumin with or without additional laser irradiation.

CONCLUSIONS

The greatest antibacterial efficacy was observed in samples treated with aPTT. Using curcumin as a photosensitizing agent for 445 nm laser irradiation did not result in improved antibacterial effectiveness in comparison with laser alone.