Photodynamic inactivation of microorganisms present on complete dentures. A clinical investigation

Abstract

The aim of this study was to evaluate the effectiveness of photodynamic therapy (PDT) for the disinfection of complete dentures. Biofilm samples were collected from dentures of 60 denture users who were randomly divided into four experimental groups (n = 15 each): subjects whose maxillary dentures were sprayed with 50 and 100 mg/l of Photogem® suspension (groups P50S and P100S) and patients whose maxillary dentures were treated with 50 and 100 mg/l of Photogem® gel (groups P50G and P100G). Dentures with photosensitizers were left in the dark for 30 min (pre-irradiation time) and then irradiated with blue LED light at 37.5 J/cm(2) (26 min). Denture samples were taken with sterile cotton swab before (left side surfaces) and after (right side surfaces) PDT. All microbial material was diluted and plated on selective media for Candida spp., Staphylococcus mutans spp., streptococci and a non-selective media. After incubation (48 h/37°C), the number of colony-forming units (cfu/ml) was counted. Microorganisms grown on selective media were identified using biochemical methods before and after PDT. The data were submitted to McNemar and Kruskal-Wallis tests (α = 0.05). No growth after PDT was observed in 60, 53, 47, and 40% of dentures from P100G, P50G, P100S, and P50S groups, respectively. When evidence of microorganisms' growth was observed, PDT regimens eliminated over 90% of microorganisms on dentures. This clinical study showed that PDT was effective for disinfecting dentures.

An In Vitro Comparison of Antimicrobial Effects of Curcumin-Based Photodynamic Therapy and Chlorhexidine, on Aggregatibacter actinomycetemcomitans

“…PDT involves three main components: visible light, a photosensitizer (PS) and oxygen molecules. 11 In this method the PS, which is a photoactivatable substance selective for the prokaryotic target cells, binds to the cells and is activated by light at a specific wavelength. Free radicals are formed, such as oxygen species that have a toxic effect on cells.…”

“…Free radicals are formed, such as oxygen species that have a toxic effect on cells. [11][12][13][14] PDT is a repeatable procedure which costs less than other methods, has a broad spectrum microbicidal effects, is safe for the host tissue, and can reach inaccessible sites. 15 Another alternative method to treat periodontal diseases is to find substances with anti-plaque effects that can inhibit bacterial reproduction.…”

Susceptibility of clinical isolates of Candida to photodynamic effects of curcumin

“…Candida albicans represents the predominant species, while Candida tropicalis and Candida glabrata are considered the second most frequent [1,2]. These microorganisms can also act as opportunist pathogens, being the so-called non-albicans Candida species (NAC) increasingly recognized as important agents of human infection.…”

Cell Membrane Integrity of Candida Albicans after Different Protocols of Microwave Irradiation

“…For this reason, dentures act as a potential cause of cross-infection transmission between patients and dental personnel. Likewise, as a reservoir of pathogens, intaglio surfaces of acrylic resin dentures enhance the infection potential of microorganisms and can favor the riseof oral in fections [1,2].…”

“…Th is condition is mainly caused by microorganis ms of the Candida genus and affects the palate of approximately 65% of denture wearers. Candida albicans represents the predominant species, but the socalled non-albicans Candida species are also recognized as important agents of the infection [2]. Management of denture stomatitis is typically drug based but relapse and recurrence frequently require repeated courses of antifungal therapy [4].…”