Photodynamic inactivation of Candida ssp. on denture stomatitis. A clinical trial involving palatal mucosa and prosthesis disinfection.

Denture stomatitis (DS) is the most common oral fungal infection in denture wearers. Photodynamic inactivation (PDI) has been showing to be an effective technique in vivo against fungi, including fungal infections in the oral cavity. The disinfection of both oral mucosa and denture may represent a real advantage in terms of fungus control. This clinical study was designed to explore methylene blue (MB)-mediated PDI on oral mucosa and prosthesis of patients with DS. Subjects with DS were divided into two groups. One group received treatment based on the use of oral miconazole gel 2% (MIC). The other group received treatment by PDI using MB at 450 µg/mL and a diode laser (λ = 660 nm) with 100 mW and fluence of 28 J/cm2. Clinical outcome was evaluated regarding the degree of oral mucosa erythema and microbiological reduction of Candida spp. located in both palatal mucosa and prosthesis. Our results showed that PDI was significantly more effective than MIC in ameliorating inflammation after 15 days. Following 30 days, no statistically significant differences were observed between groups. Regarding the fungal burden, although the MIC group has presented more pronounced inactivation than PDI for both mucosa and prosthesis, no statistically significant differences were detected between them. This clinical study suggests that PDI can reduce fungal load and decrease the inflammation degree in patients with Candida-associated denture stomatitis.

Phenomenon of laser power loss during curettage of infected periodontal pockets.

OBJECTIVE: The purpose of this study was to evaluate the reduction in laser power output (PO) at the optical fiber tip during laser curettage of infected periodontal pockets. BACKGROUND DATA: The combination of mechanical debridement with laser therapy has been used successfully in the treatment of periodontitis. METHODS: The study group consisted of 28 teeth selected in 12 patients with chronic periodontitis. The teeth were treated with scaling and root planing (SRP), and infected pocket epithelium was removed with an 810-nm diode laser operating at a laser power of 1.7 W in continuous-wave mode (CW). Laser power was set to 1.0 W at the control panel before each measurement to facilitate mathematical analysis, and PO at the optical fiber tip was measured using a power meter. Four laser applications were performed per tooth (duration, 10-15 sec per application; total duration, 40-60 sec per tooth). The fiber tip was cleaved every four applications. Also, 28 irradiations (four PO measurements per irradiation) were performed in non-contact mode and used as controls. RESULTS: There were significant PO losses between applications in the study group. PO losses of 20.89%, 30.39%, and 40.26% were found between the first and second, first and third, and first and fourth applications, respectively. A low transmission loss of the optical fiber was observed in the control measurements (mean PO loss of 1.58% between the first and fourth irradiations). CONCLUSIONS: Our results indicated that optical fiber tips need to be cleaved frequently during laser curettage to minimize PO loss.