Photodynamic therapy (PDT) is a technique used for the oral disinfection. In dentistry, PDT for microbial inactivation may reduces both dental plaque and risk of developing caries as well as contributes to treat gingivitis, periodontitis, peri-implantitis and endodontic diseases. The investigators hypothesis was that PDT with blue light and curcumin promotes oral disinfection during 2 hours after treatment.

PDT uses a non-toxic drug that is activated by exposure to light in the presence of oxygen. The excited state this drug transfers energy or electrons to ground state molecular oxygen producing cytotoxic effects on cell. There are productions of reactive oxygen species (ROS) and disrupts several of the cell's functions. This results in bacterial disinfection. In order to perform the PDT on the oral cavity, a device based on blue LED with transparent acrylic diffuser tip and cylindrical shape was developed.

Inclusion Criteria:

• non-users of any antibiotic therapy
• those who do not perform any oral hygiene, such as flossing, brushing and antiseptic mouthwash
• those who performed 12-hour fasting prior the treatment and measurements

Exclusion Criteria:

• oral cancer
• smoking habits
• pregnancy
• patients with partial or total dentures
• orthodontic brackets users