Effect of antimicrobial photodynamic therapy with different photosensitizers and adhesion protocol on the bond strength of resin composite to sound dentin

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

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An orthodontic acrylic resin containing seaweed Ulva lactuca as a photoactive phytocompound in antimicrobial photodynamic therapy: Assessment of anti-biofilm activities and mechanical properties

Photodiagnosis and Photodynamic Therapy ◽

10.1016/j.pdpdt.2021.102295 ◽

2021 ◽

pp. 102295

Author(s):

Maryam Pourhajibagher ◽

Abbas Salehi-Vaziri ◽

Mohammad Noroozian ◽

Hossein Akbar ◽

Farzaneh Bazarjani ◽

...

Keyword(s):

Mechanical Properties ◽

Photodynamic Therapy ◽

Acrylic Resin ◽

Ulva Lactuca ◽

Antimicrobial Photodynamic Therapy ◽

Therapy Assessment

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Photodynamic Therapy Combined with Antibiotics or Antifungals against Microorganisms That Cause Skin and Soft Tissue Infections: A Planktonic and Biofilm Approach to Overcome Resistances

Pharmaceuticals ◽

10.3390/ph14070603 ◽

2021 ◽

Vol 14 (7) ◽

pp. 603

Author(s):

Vanesa Pérez-Laguna ◽

Isabel García-Luque ◽

Sofía Ballesta ◽

Antonio Rezusta ◽

Yolanda Gilaberte

Keyword(s):

Photodynamic Therapy ◽

Soft Tissues ◽

Combined Treatment ◽

Resistance Pattern ◽

Antimicrobial Photodynamic Therapy ◽

Antimicrobial Drugs ◽

Bacteria And Fungi ◽

High Level ◽

Selection Of

The present review covers combination approaches of antimicrobial photodynamic therapy (aPDT) plus antibiotics or antifungals to attack bacteria and fungi in vitro (both planktonic and biofilm forms) focused on those microorganisms that cause infections in skin and soft tissues. The combination can prevent failure in the fight against these microorganisms: antimicrobial drugs can increase the susceptibility of microorganisms to aPDT and prevent the possibility of regrowth of those that were not inactivated during the irradiation; meanwhile, aPDT is effective regardless of the resistance pattern of the strain and their use does not contribute to the selection of antimicrobial resistance. Additive or synergistic antimicrobial effects in vitro are evaluated and the best combinations are presented. The use of combined treatment of aPDT with antimicrobials could help overcome the difficulty of fighting high level of resistance microorganisms and, as it is a multi-target approach, it could make the selection of resistant microorganisms more difficult.

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Micro Push-Out Bond Strength of Resin Composite to Dentin in Primary Dentition Using Three Universal Adhesives with Different pH: An In Vitro Study

Applied Sciences ◽

10.3390/app11146349 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6349

Author(s):

Regina María Del Río Carrillo ◽

Pedro Molinero-Mourelle ◽

Vicente Vera ◽

Pablo Romero Villaba ◽

Elizabeth Casañas ◽

...

Keyword(s):

Bond Strength ◽

Resin Composite ◽

In Vitro Study ◽

Primary Dentition ◽

Vitro Study ◽

Deciduous Tooth ◽

Universal Adhesives ◽

Type Of Failure ◽

Push Out

To evaluate the bond strength of different universal adhesives on deciduous tooth dentineand their relationship with the composition and potential of hydrogen (pH). Methods: An in vitromicro push-out test on 150 samples (n = 50) per group per adhesive, namely, Adhese Universal(ADH; Ivoclar Vivadent), Futurabond U (FUT; Voco GmbH) (Test), and Scotchbond Universal withpre-conditioning (SCO; 3M) (Control), to record bond strength (BS) and type of adhesive failure.Results: The results of the different adhesives (megapascals (MPa)) varied, showing no statisticalsignificance. The corresponding averages are in MPa: ADH, 13.66 2.81; FUT, 14.48 2.88; SCO,14.98 3.96. Additionally, the frequency of type of failure was as follows: mixed (60.7%), adhesive(27.3%), and cohesive (12%). Conclusions: SCO, with a pH of 2.7, showed greater resistance tofracture, while FUT, with a pH of 2.3 and no pre-conditioning, approached the same values, being aone-step adhesive. No relationship was found between failure and type of adhesive.

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