No abstract

Photodynamic therapy-generated ROS inactivates A. actinomycetemcomitans both in planktonic and biofilm cultures, even in small concentrations of the photosensitizing agent, and it does not cause damage to fibroblast cells under the same conditions.

No abstract

No abstract

Riboflavin and thiamine exacerbate the anti-inflammatory activity of dexamethasone and reduce production of TNF-α and IL-6.

The main objective of this class experiment is to show the time-dependent consumption of a fermentable sugar (glucose) in the presence and absence of a non-fermentable sugar (xylose) by bacteria in anaerobic conditions. The observation of the pH decrease due to acid production and the turbidity increase as a result of cell multiplication, both in function of time, enables an interesting discussion regarding the metabolic pathways and the products of anaerobic fermentation of carbohydrates. Also the time-dependent disappearance of glucose due to its metabolic consumption is compared with the non-disappearance of xylose and permits a discussion of the function of glycolysis and pentose phosphate pathways as metabolic routes.

No abstract

The main focus of this laboratory exercise was to investigate the photodynamic therapy (PDT) acting over Streptococcus mutans. A handheld photopolymerizer and a classical photosensitizer (Rose Bengal) were used to induce photodynamic response. In this way, a suspension of S. mutans was treated with different concentrations of Rose Bengal (0 -10 mol/liter), irradiated with a light (400 -600 nm) for 20 s, and then cell viability was evaluated. It was observed that the light (per se) is not toxic, and in the dark, Rose Bengal is toxic only to the cells tested at concentrations above 5.0 mol/liter. Under light exposure, concentrations of Rose Bengal above 0.5 mol/liter killed all S. mutans. Therefore, for the purpose of our work, the photoactivation of Rose Bengal using the handheld photopolymerizer was efficient in bacteria inactivation.