The effect of dentifrice abrasion on denture topography and the subsequent retention of microorganisms on abraded surfaces

Statement of problem. Denture surfaces provide hard nonshedding niches for the adhesion and subsequent accumulation of oral microorganisms into denture plaque, which can harbor various potential pathogens linked with oral mucosal lesions and inhalation pneumonia. The initial adhesion is the prerequisite for subsequent biofilm growth, and surface roughness niches facilitate this process by trapping cells. Retained microorganisms are then able to proliferate when the denture is returned to the oral cavity.Purpose. The purpose of this study was to measure the amount and strength of the attachment of microorganisms to a roughened denture acrylic resin surface. An increase in surface roughness increases the retention of microorganisms and a greater amount of cell-surface contact interface may increase the strength of adhesion and, therefore, retention. Cleaning denture surfaces with brushes and dentifrices can influence the denture surface topography and, therefore, may affect retention.Material and methods. Denture acrylic resin specimens were abraded to provide different surface roughness. The amount of attachment of Streptococcus oralis or Candida albicans to these surfaces was assessed by measuring the area of a microscopic field covered by stained cells after 1 hour of incubation. The strength of attachment was assessed with atomic force microscopy, whereby an increasing force was applied to the attached cells until they detached from the surface.Results. Both bacteria and yeast cells were retained in increasing amounts on surfaces of increasing roughness. Cells were most strongly attached on surfaces whose linear features (scratches) were of comparable size with the cells (the streptococci on the low-abraded surfaces, and the yeast on high-abraded surfaces).Conclusion. Analysis of findings reveal that even small abrasions may enhance retention on denture surfaces and reduce surface cleanability. The strength of attachment instead of the amount is more important in terms of surface hygiene. © 2014 Editorial Council for the Journal of Prosthetic Dentistry

Distribution Patterns of E-Cadherin, Type VII Collagen and Fibronectin in Denture-Related Stomatitis: A Preliminary Study

The distribution of epithelial E-cadherin, basement membrane type VII collagen, and underlying connective tissues fibronectin were investigated immunohistochemically and compared in normal palatal mucosa and in denture-related stomatitis (DRS) derivatives using monoclonal antibodies.Biopsies of palatal mucosa were obtained from twelve patients enrolled in this study, 8 with type II DRS and 4 with healthy mucosa

Increased prevalence and geographic spread of the cardiopulmonary nematode Angiostrongylus vasorum in fox populations in Great Britain

SUMMARYThe nematode Angiostrongylus vasorum is becoming more widely recorded globally, and is of increasing concern as a cause of disease in dogs. Apparent geographic spread is difficult to confirm due to a lack of standardized disease recording systems, increasing awareness among veterinary clinicians, and recent improvements in diagnostic technologies. This study examines the hypothesis that A. vasorum has spread in recent years by repeating the methods of a previous survey of the fox population. The hearts and lungs of 442 foxes from across Great Britain were collected and examined by dissection and flushing of the pulmonary circulation and microscopic inspection of tracheal scrapes. Sampling and parasite extraction methods were identical to an earlier survey in 2005 to ensure comparability. Prevalence of A. vasorum was 18·3% (exact binomial confidence bounds 14·9–22·3), compared with 7·3% previously (5·3–9·9, n = 546), and had increased significantly in most regions, e.g. 7·4% in the Northern UK (previously zero) and 50·8% in the south-east (previously 23·2%). Other nematodes identified were Crenosoma vulpis (prevalence 10·8%, CI 8·1–14·2) and Eucoleus aerophilus (31·6%, CI 27·3–36·2). These data support the proposal that A. vasorum has increased in prevalence and has spread geographically in Great Britain.</jats:p