Photodynamic Therapy Against Candida Spp. in Complete Denture Wearers

Different Candida species, including albicans, tropicalis, and parapsilosis, are present in the human oral microbiota, gastrointestinal tract and vagina. These species are typically harmless commensals. Candida albicans, the most prevalent species, may be present in up to 80% of healthy individuals. This species is found with high frequency in dental prostheses and is thought to be the main pathogen associated with stomatitis in elderly denture wearers. Biofilms of Candida albicans are usually found in intravenous catheters, prostheses, and these biofilms promote a high resistance to antifungal drugs. The standard treatment of stomatitis is topical antifungal agents, including nystatin and miconazole. The use of topical antifungal agents has caused some problems. Poor responses to these agents are the result of dilution and fast elimination of the drug because of the action of the saliva, which reduced the drug's concentration. The drug's toxicity can cause mild and transient gastrointestinal side effects, such as nausea, vomiting and diarrhea. Alternative treatments or adjuvant treatments have been used to treat these diseases, such as the use of probiotic bacteria and photodynamic therapy (PDT) using a non-toxic dye (photosensitizer - PS) in combination with a source of visible light with a peak wavelength suitable for absorption by the PS. The photodynamic process rapidly generates reactive oxygen species (ROS) such as peroxides, hydroxyl radicals, superoxide ions and singlet oxygen. Singlet oxygen has been implicated as the major causative agent of cellular damage in the photodynamic process, but it does not cause cellular damage in host tissues. The amount of ROS formation is the main predictor of yeast killing.

This study aimed to evaluate the effectiveness of photodynamic therapy (PDT) in the treatment of denture stomatitis in complete denture wearers.

Inclusion criteria

• patients presenting denture-related stomatitis, confirmed by clinical and microbiological evaluation

Exclusion criteria

• were based on the patients' medical history, and were excluded patients with a history of head and neck cancer, those with type III DS (classification proposed by Newton), and individuals who had received or were receiving treatment with antibiotics, antifungal agents or steroids for the past three months.