Luminescent Measurements

For the luminescence measurements, the chosen 100 kBq ²²⁹Th:CaF₂ crystal was placed in the focal point of the entrance of a 234/302 McPherson spectrometer. The slit in front of the crystal was set to an opening of 1 mm, corresponding to 4 nm resolution. Any radioluminescence was then spectrally resolved and imaged on a Hamamatsu R7639 PMT cooled to −30  ${}^{\circ }\text{C}$ . The PMT is cooled to reduce dark noise to 0.5 cps, otherwise Cherenkov radiation could not be detected. A shutter was used to take continuous dark measurements while the signal was integrated for 9 h per wavelength setting.

The study involved patients aged 50 to 59 years who were made complete removable dentures for the lower jaw for the first time. The distribution of the patients by gender, the degree of atrophy of the alveolar process and the condition of the mucous membrane are presented in Table 1.
Table 1All patients – 23 persons in total were divided into four groups:
- group 1 – persons who used full removable dentures and did not use any fixations and adhered to conventional oral hygiene;
- group 2 – patients with full removable dentures who used the cream “Corega” to strengthen the fixation from the first day of prosthetics and adhered to conventional oral hygiene;
- group 3 – patients with complete removable dentures who used Corega Comfort (GSK – GlaxoSmithKline) to strengthen the fixation from the first day of prosthetics and adhered to conventional oral hygiene;
- group 4 – patients with complete removable dentures who used Corega Comfort (GSK) and performed antibacterial cleaning of dentures with Biotablets “Corega” for cleaning dentures to enhance the fixation from the first day of prosthetics.
The dentures were made of acrylic resin and clinical methods of additional fixation were used if necessary. Mycological examination of the patients included microscopic examination of smears using conventional and luminescent methods of staining smears from the surface of the dentures. Cultural studies with quantitative estimation of the fungi were also conducted. The patients were carried out studies after prosthetics in the terms: 14 days, 1, 2, 6 months after denture fitting. Bacteriological investigations were conducted to study the number and biological properties of microorganisms on the surface of the dentures. A sterile cotton swab soaked in saline was used to take the material from the surface of the dentures for isolation and quantitative estimation of the microorganisms followed by inoculation of the material on yolk-salt agar (YSA). The selection of test colonies on YSA was made after incubation at a temperature of 37°C for 2 days.
The basis for the quantitative estimation of colonies was the severity of the lecithinase reaction (formation of a cloudy zone and a rainbow crown around the colony). Microscopic methods were used to determine the species of selected fungal cultures. To quantify the selected cultures of the fungi, the material was taken from the surface of the denture on an empty stomach. A sterile cotton swab, turning round, carefully wiped the surface of the denture. Then the swab was immersed in a vial of 5 ml of saline and sterile balls. The contents of the vial have been shaken for 5 minutes. Then 0.1 ml of the liquid from the vial was inoculated into a Petri dish with Saburo agar. To suppress other microbial flora and obtain a pure culture of fungi penicillin and streptomycin was added to the culture medium at the rate of 100 IU (international unit) per 1 ml of the medium. The material was evenly distributed on the agar surface with a Drygalsky spatula. The cultures have been incubated at 37°C for 48 hours. To quantify the results, cultures in Petri dishes were divided into a number of sectors, where the number of grown colonies was counted. Then the total number of colonies was determined and multiplied by the degree of dilution of the pathological material in saline.