Antimicrobial Photodynamic Therapy as a Technique for Decontamination of Acrylic Resin Devices Provided by Different Dental Laboratories.

Introduction: Dentures, occlusal splints, surgical guides and orthodontic appliances are examples of acrylic resin devices made in dental laboratories, which must be disinfected and even sterilized before insertion into the oral cavity. This study evaluated the antimicrobial effect of photodynamic therapy (PDT) applied to acrylic resin specimens received from different laboratories. Methods: Three hundred standardized specimens were ordered from six randomly selected laboratories registered in the Council of Dentistry of Ceará (n=50). The PDT consisted in the association of 22 µM erythrosine, as a photosensitizer (P), and a 520-nm LED at 38 J/cm2 (L). The specimens of each laboratory were randomly distributed into five groups: positive control, sterilized with ethylene oxide; negative control, untreated (P-L-); erythrosine control, only stained (P+L-); LED control, only irradiated (P-L+); PDT (P+L+). Then, the specimens were individually sonicated in saline solution; the suspension was diluted, plated on culture mediums (blood agar, sabouraud dextrose agar and a non-selective chromogenic agar), and incubated for 48 hours at 37°C. Colony-forming-unit (CFU) counts were done and statistical tests of Kruskal-Wallis/Dunn were carried out. Results: The specimens from all laboratories were contaminated with bacteria and yeasts. Staphylococcus aureus, Staphylococcus saprophyticus, Escherichia coli, Enterococcus spp., Klebsiella and Pseudomonas spp. were identified. The PDT significantly reduced CFU counts (P<0.0001), compared to P-L-. Conclusion: PDT was able to effectively decontaminate the acrylic resin specimens provided from dental laboratories.

GOHAI and OHIP-EDENT Evaluation in Removable Dental Prostheses Users: Factorial Analysis and Influence of Clinical and Prosthetic Variables.

PURPOSE: To assess the degree of satisfaction and quality of life of patients with removable prostheses using the Geriatric Oral Health Assessment Index (GOHAI) and Oral Health Impact Profile in Edentulous Adults (OHIP-EDENT), in addition to evaluating the questionnaires for their validation. MATERIALS AND METHODS: Eighty patients participated in the study after completing prosthetic rehabilitation treatment. Patients were evaluated using the OHIP-EDENT and GOHAI questionnaires to assess the criteria for quality of life, esthetics, phonetics, masticatory function, stability, comfort, and alteration of taste and pain related to the completed prostheses. The results were subjected to the chi-squared test, Fisher's exact test, and a multinomial logistic regression model, with a significance level of 5%. RESULTS: The most commonly used removable prosthesis was mandibular removable partial denture (RPD) (n = 43, 53.8%), followed by maxillary RPD (n = 42, 52.5%), maxillary complete denture (CD) (n = 33, 41.3%), and mandibular CD (n = 31, 38.8%). Most patients had to have one (n = 29, 36.3%), two (n = 21, 26.3%), or none (n = 18, 23.8%) adjustments in their prostheses. Five (6.3%) patients' prostheses required three adjustments, and six (7.5%) required four or more adjustments. All reported improvement in esthetics after using the prostheses (p < 0.05). The validation of the questionnaire proved to be more viable when completed without the presence of specific domains. CONCLUSION: The results of this study indicated that removable prostheses improved the quality of life of rehabilitated patients. The questionnaires used need to be answered and evaluated in their entirety for validation.

Photosensitization of in vitro biofilms formed on denture base resin.

STATEMENT OF PROBLEM: Proper sterilization or disinfection of removable prostheses and surgical guides has been problematic in dental practice because of the absence of simple and low-cost techniques that do not cause damage to acrylic resins. PURPOSE: The purpose of this study was to study the effect of photodynamic therapy against Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans biofilms formed on acrylic resin specimens. MATERIAL AND METHODS: The specimens were sterilized in ethylene oxide gas and submitted to in vitro biofilm growth. The photodynamic therapy consisted of the application of 0.05% methylene blue (P+) conjugated to irradiation with a light-emitting-diode of 630 nm and 150 mW (L+). The specimens were randomly divided into groups (n=5): negative control (P-L-); stained and irradiated at 10 J/cm(2) (P+L+ 10); stained and irradiated at 30 J/cm(2) (P+L+ 30); stained and not irradiated (P+L-); not stained and irradiated at 10 J/cm(2) (P-L+ 10); not stained and irradiated at 30 J/cm(2) (P-L+ 30); and gold standard (GS), sterilized. Afterward, the specimens were submitted to contact with culture medium agar for 10 minutes in petri plates, which were incubated for 48 hours at 37°C. The number of colony-forming units was obtained, and the data were expressed according to scores (1=0; 2=1-10; 3=11-100; 4=101-1000) and analyzed by the Friedman and Dunn tests (α=.05). RESULTS: Streptococcus mutans was sensitized by (P+L-); P aeruginosa and C albicans were also sensitized by the dye but showed a slight microbial reduction with (P+L+ 30), as did S aureus (P>.05); E coli presented an initial score of 3 and achieved a bacterial reduction to score 2 with (P+L+ 30) (P=.039). CONCLUSIONS: Photodynamic therapy was effective in reducing E coli counts on biofilms formed on acrylic resin specimens. The inhibition of microorganism growth tended to be directly proportional to the amount of energy provided by the light-emitting diode.