De Foggi Camila Cristina, Ayres Marina Siqueira Bambini, Feltrin Guilherme Paladini, Jorge Janaina Habib, Machado Ana Lucia
Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Dental School, Campus Araraquara, São Paulo, Brazil.
Private practice, Araraquara, São Paulo, Brazil.
Am J Dent. 2018 Feb;31(1):45-52.
To investigate the influence of surface characteristics and saliva on the adhesion and biofilm formation of Candida glabrata and methicillin-resistant Staphylococcus aureus (MRSA) to soft liners and tissue conditioners.
For each material (Ufi Gel P - UG; Sofreliner S - SS; Trusoft - TR; Coe Comfort - CC; Softone - ST), specimens were prepared and roughness (Ra), hydrophobicity (water contact angles-WCA) and surface free energy (SFE) were measured. Surface morphology was also analyzed using scanning electron microscopy (SEM). Specimens were incubated in C. glabrata or MRSA suspensions for 90 minutes (adhesion) or 48 hours (biofilm). The absorbance (AB) was measured by XTT assay. Experiments were performed using specimens that were either uncoated or had been coated with saliva. Data were analyzed using one- or two-way ANOVAs, followed by Tukey's test (α= 0.05).
TR exhibited the highest Ra and UG the lowest. SEM images also showed that UG and SS had smooth surfaces, while TR presented several irregularities and pores. In the absence of saliva, UG and SS presented higher WCA and lower SFE than the other materials. XTT results showed that, in the C. glabrata adhesion assay, the AB value was higher for TR followed by UG > CC> SS> ST. For the biofilm formation of C. glabrata, AB values were in the following order TR > CC = UG > ST = SS. In the adhesion assay, AB values obtained for MRSA were TR > UG = CC > ST > SS and for the biofilm formation were TR > ST > CC > UG > SS. Saliva decreased the WCA and increased the SFE for all materials. In general, the presence of saliva decreased the adhesion and biofilm formation of both microorganisms to the acrylic-based material (TR) and tissue conditioners (CC and ST), and increased for the silicone-based soft liners (UH and SS). Surface characteristics and the influence of saliva varied among materials. Roughness seemed to favor C. glabrata and MRSA adhesion and biofilm formation.
The presence of microorganisms on denture liners can irritate the oral tissues and contribute to systemic diseases. Colonization with more tolerant microorganisms such as C. glabrata and MRSA may expose patients to a greater risk of infection, mainly in immunocompromised hosts, such as aged individuals after treatment of oral cancer. For this, it is important to investigate the surface characteristics of soft liners and tissue conditioners, as well as saliva, and their influence on the adhesion and biofilm formation of C. glabrata and methicillin-resistant Staphylococcus aureus.
研究表面特性和唾液对光滑念珠菌及耐甲氧西林金黄色葡萄球菌（MRSA）黏附于软衬材料和组织调节剂以及生物膜形成的影响。
针对每种材料（Ufi Gel P - UG；Sofreliner S - SS；Trusoft - TR；Coe Comfort - CC；Softone - ST），制备标本并测量粗糙度（Ra）、疏水性（水接触角 - WCA）和表面自由能（SFE）。还使用扫描电子显微镜（SEM）分析表面形态。将标本在光滑念珠菌或MRSA悬液中孵育90分钟（黏附）或48小时（生物膜）。通过XTT法测量吸光度（AB）。实验使用未涂层或已用唾液涂层的标本进行。数据采用单因素或双因素方差分析，随后进行Tukey检验（α = 0.05）。
TR的Ra最高，UG的最低。SEM图像还显示UG和SS表面光滑，而TR有一些不规则和孔隙。在无唾液时，UG和SS的WCA较高，SFE较低，高于其他材料。XTT结果显示，在光滑念珠菌黏附试验中，TR的AB值较高，其次是UG > CC > SS > ST。对于光滑念珠菌的生物膜形成，AB值顺序为TR > CC = UG > ST = SS。在黏附试验中，MRSA的AB值为TR > UG = CC > ST > SS，生物膜形成的AB值为TR > ST > CC > UG > SS。唾液降低了所有材料的WCA并增加了SFE。总体而言，唾液的存在降低了两种微生物对丙烯酸基材料（TR）和组织调节剂（CC和ST）的黏附及生物膜形成，而对硅酮基软衬材料（UH和SS）则增加。表面特性和唾液的影响因材料而异。粗糙度似乎有利于光滑念珠菌和MRSA的黏附及生物膜形成。
义齿衬里上存在微生物会刺激口腔组织并导致全身性疾病。被更具耐受性的微生物如光滑念珠菌和MRSA定植可能使患者面临更大的感染风险，主要在免疫功能低下的宿主中，如口腔癌治疗后的老年个体。因此，研究软衬材料和组织调节剂的表面特性以及唾液及其对光滑念珠菌和耐甲氧西林金黄色葡萄球菌黏附及生物膜形成的影响很重要。
