de Castro Denise T, Valente Mariana L C, Agnelli José Augusto M, Lovato da Silva Cláudia H, Watanabe Evandro, Siqueira Renato L, Alves Oswaldo L, Holtz Raphael D, dos Reis Andréa C
Doctoral student, Department of Dental Materials and Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, Brazil.
Associate Professor, Department of Materials Engineering, Federal University of São Carlos (UFSCAR), São Carlos, Brazil.
J Prosthet Dent. 2016 Feb;115(2):238-46. doi: 10.1016/j.prosdent.2015.09.003. Epub 2015 Nov 3.
The accumulation of bacteria on the surface of dental prostheses can lead to systemic disease.
The purpose of this in vitro study was to evaluate the growth of Staphylococcus aureus and Pseudomonas aeruginosa on the surface of autopolymerizing (AP) and heat-polymerizing (HP) acrylic resins incorporated with nanostructured silver vanadate (β-AgVO3) and its impact strength.
For each resin, 216 circular specimens (9 × 2 mm) were prepared for microbiologic analysis and 60 rectangular specimens (65 × 10 × 3.3 mm) for mechanical analysis, according to the percentage of β-AgVO3: 0%, control group; 0.5%; 1%; 2.5%; 5%; and 10%. After a biofilm had formed, the metabolic activity of the bacteria was measured using the XTT reduction assay (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) (n=8), and the number of viable cells was determined by counting colony forming units per milliliter (CFU/mL) (n=8). Confocal laser scanning microscopy (CLSM) was used to complement the analyses (n=2). The mechanical behavior was evaluated by impact strength assays (n=10). Data were analyzed by 2-way ANOVA, followed by the Tukey honestly significant difference (HSD) post hoc test (α=.05).
The addition of 5% and 10% β-AgVO3 significantly decreased the metabolic activity of P. aeruginosa for both resins (P<.05). The HP resin promoted a greater reduction in metabolic activity than the AP resin (P<.05). No difference was found in the metabolic activity of S. aureus according to the XTT (P>.05). The number of CFU/mL for S. aureus and P. aeruginosa decreased significantly when 5% and 10% β-AgVO3 were added (P<.001). These concentrations significantly reduced the impact strength of the resins (P<.001) because the system was weakened by the presence of clusters of β-AgVO3.
The addition of β-AgVO3 can provide acrylic resins with antibacterial activity but reduces their impact strength. More efficient addition methods should be investigated.
假牙表面细菌的积累可导致全身性疾病。
本体外研究的目的是评估金黄色葡萄球菌和铜绿假单胞菌在掺有纳米结构钒酸银（β-AgVO3）的自凝（AP）和热凝（HP）丙烯酸树脂表面的生长情况及其冲击强度。
根据β-AgVO3的百分比，为每种树脂制备216个圆形标本（9×2mm）用于微生物分析，60个矩形标本（65×10×3.3mm）用于力学分析：0%，对照组；0.5%；1%；2.5%；5%；和10%。生物膜形成后，使用XTT还原试验（2,3-双-（2-甲氧基-4-硝基-5-磺基苯基）-2H-四唑-5-甲酰苯胺）测量细菌的代谢活性（n=8），通过计算每毫升菌落形成单位（CFU/mL）确定活细胞数量（n=8）。共聚焦激光扫描显微镜（CLSM）用于辅助分析（n=2）。通过冲击强度试验评估力学性能（n=10）。数据通过双向方差分析进行分析，随后进行Tukey真实显著差异（HSD）事后检验（α=0.05）。
添加5%和10%的β-AgVO3显著降低了两种树脂中铜绿假单胞菌的代谢活性（P<0.05）。HP树脂比AP树脂促进了更大程度的代谢活性降低（P<0.05）。根据XTT法，金黄色葡萄球菌的代谢活性未发现差异（P>0.05）。添加5%和10%的β-AgVO3时，金黄色葡萄球菌和铜绿假单胞菌的CFU/mL数量显著减少（P<0.001）。这些浓度显著降低了树脂的冲击强度（P<0.001），因为β-AgVO3团簇的存在削弱了体系。
添加β-AgVO3可使丙烯酸树脂具有抗菌活性，但会降低其冲击强度。应研究更有效的添加方法。
