Verran Joanna, Jackson Sarah, Coulthwaite Lisa, Scallan Anthony, Loewy Zvi, Whitehead Kathryn
Professor, School of Health Care Science, Manchester Metropolitan University, Manchester, UK.
Former doctoral student, School of Health Care Science, Manchester Metropolitan University, Manchester, UK.
J Prosthet Dent. 2014 Dec;112(6):1513-22. doi: 10.1016/j.prosdent.2014.05.009. Epub 2014 Jul 4.
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.
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.
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.
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).
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.
义齿表面为口腔微生物的黏附及随后在义齿菌斑中的积聚提供了坚硬且不易脱落的微环境，义齿菌斑可能藏有与口腔黏膜病变和吸入性肺炎相关的各种潜在病原体。初始黏附是后续生物膜生长的前提条件，表面粗糙度微环境通过捕获细胞促进这一过程。当义齿放回口腔时，留存的微生物便能够增殖。
本研究的目的是测量微生物在粗糙化的义齿丙烯酸树脂表面的附着量和附着强度。表面粗糙度增加会提高微生物的留存率，更多的细胞 - 表面接触界面可能会增加黏附强度，进而提高留存率。用刷子和牙膏清洁义齿表面会影响义齿表面形貌，因此可能会影响留存率。
对义齿丙烯酸树脂标本进行研磨以提供不同的表面粗糙度。通过测量孵育1小时后染色细胞覆盖的显微镜视野面积，评估口腔链球菌或白色念珠菌在这些表面的附着量。用原子力显微镜评估附着强度，即对附着的细胞施加逐渐增加的力，直至它们从表面脱落。
细菌和酵母细胞在粗糙度增加的表面上的留存量均增加。细胞在其线性特征（划痕）与细胞大小相当的表面上附着最强（低研磨表面上的链球菌，高研磨表面上的酵母）。
研究结果分析表明，即使是小的磨损也可能增强义齿表面的留存率并降低表面清洁度。就表面卫生而言，附着强度而非附着量更为重要。
