[Oral candidiasis and dentures]. / Candidoses orales et prothèses dentaires.

Yeasts belonging to the Candida genus usually colonize the human oral cavity. Immunocompromised patients or individuals with an imbalance of their oral microflora can develop yeast infections from this reservoir. However, saliva protects oral mucosa against candidosis; in turn, dry mouth is associated with increased yeast counts and candidosis risk. In vivo and in vitro studies have shown Candida incorporation into biofilms covering different biomaterials such as dentures: these biofilms may be an increased risk factor for invasive candidosis when the host immune system is compromised. Daily denture brushing is recommended to all wearers. Family or healthcare workers must take over this task when there is autonomy loss, especially in the elderly. In case of candidosis in denture wearers, decontamination of dentures is mandatory. Antimycotics (azoles, nystatin) must be kept for curative treatments of infected patients; they are less active against Candida biofilms on dentures and could lead to emergent resistance if applied daily to dentures against yeast colonization. There are several antiphlogistic solutions with antifungal properties. Nevertheless, literature data does not integrate all aspects of denture care: welfare of denture wearers, prevention of candidosis, biomaterial defects after decontamination processing, and taking into account possible Candida biofilm development. Daily brushing of dentures remains the key recommendation.

Adsorption of peroxidase on titanium surfaces: A pilot study.

The present study demonstrates the in vitro and in vivo adsorption of peroxidase onto titanium surfaces. Titanium foils (mean +/- SEM: 365 +/- 2 mm(2), n = 114) were incubated during 30 min with lactoperoxidase (4 mg in 5 mL 100 mM phosphate buffer pH 7). After 15 washings by H(2)O, titanium foils were incubated with o-phenylenediamine (6 mg/mL) and H(2)O(2) (7 mM) during 30 min. The reaction was then stopped by the addition of HCI 1M and the absorbance of the liquid phase was read on a spectrophotometer at 492 nm. In vitro adsorbed lactoperoxidase onto titanium surfaces was 0.70 +/- 0.05 ng/mm(2) (mean +/- SEM, n = 30). X-ray photoelectron spectroscopy confirmed the incorporation of protein nitrogen onto titanium surfaces: the nitrogen atomic percentage increased from 0.9 +/- 0.3 to 12.7 +/- 0.2% (n = 3) and from 3.7 +/- 0.1 to 14.4 +/- 0. 4% (n = 5) when titanium foils were incubated in the lactoperoxidase solution during 30 min and 24 h respectively. In vivo, oral peroxidases adsorbed on titanium healing abutments from 0.01 to 0.58 ng/mm(2) (n = 19) after 2 weeks in the oral environment.