scholarly journals In vitro evaluation of microbial adhesion on the different surface roughness of acrylic resin specific for ocular prosthesis

2018 ◽  
Vol 12 (02) ◽  
pp. 176-183 ◽  
Author(s):  
Agda Marobo Andreotti ◽  
Cecília Alves De Sousa ◽  
Marcelo Coelho Goiato ◽  
Emily Vivianne Freitas da Silva ◽  
Cristiane Duque ◽  
...  

ABSTRACT Objective: The purpose of this study was to evaluate the influence of surface roughness in biofilm formation of four microorganisms (Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans) on acrylic resin surface of ocular prostheses. Materials and Methods: Acrylic resin samples were divided into six groups according to polishing: Group 1200S (1200 grit + silica solution); Group 1200; Group 800; Group 400; Group 120 and Group unpolished. Surface roughness was measured using a profilometer and surface images obtained with atomic force microscopy. Microbial growth was evaluated after 4, 24, and 48 hours of incubation by counting colony-forming units. Statistical Analysis Used: For roughness, it was performed 1-way ANOVA and parametric Tukey test α5% (P ≤ 0.05). For CFU data found, it was applied Kruskal-Wallis and Mann-Whitney tests. Results: Group 120 and 400 presented the highest roughness values. For S. epidermidis and S. aureus, Group 1200S presented the lowest values of microbial growth. For E. faecalis at 4 hour, microbial growth was not observed. C. albicans did not adhere to the acrylic resin. Except for Group 1200S, different surface roughnesses did not statistically interfere with microbial adhesion and growth on acrylic surfaces of ocular prostheses. Conclusions: The roughness did not interfere with the microbial adhesion of the microorganisms evaluated. The use of silica decreases significantly microbial growth.

2010 ◽  
Vol 4 (1) ◽  
pp. 191-194 ◽  
Author(s):  
Luca Giacomelli ◽  
Giacomo Derchi ◽  
Andrea Frustaci ◽  
Orlando Bruno ◽  
Ugo Covani ◽  
...  

Background and Aims: Polishing may increase the surface roughness of composites, with a possible effect on bacterial growth and material properties. This preliminary in vitro study evaluates the effect of three different polishing systems (PoGo polishers, Enhance, Venus Supra) on six direct resin composites (Gradia Direct, Venus, Venus Diamond, Enamel Plus HFO, Tetric Evoceram, Filtek Supreme XT). Materials and Methods: For each composite, 12 square specimens were prepared: 9 specimens were polished, three for each different method, while three specimens were used as controls. Surface roughness was determined with AFM by measuring Root Mean Square (RMS) of average height. Results: PoGo polisher determined a significantly rougher surface, versus controls, in 5 out of 6 composites evaluated. Some significant differences from unpolished controls were observed also for Enhance polishing. Polishing with Venus Supra did not result in any significant difference in surface roughness versus controls. No differences were observed between different polishing systems. Conclusions: These preliminary results suggest that Venus Supra polishing system could determine a smoother composite surface if compared to the other polishing systems tested. On this basis, we are conducting an in vivo study to evaluate bacterial colonization on some combinations of composites and polishing protocols.


2021 ◽  
Vol 5 (1) ◽  
pp. 19-23
Author(s):  
Syahrial , ◽  
Pocut Aya Sofya ◽  
Adellya Tasya Sukma

The surface of heat-cured acrylic resin on the base of artificial teeth has a risk of surface roughness. Its causes are liquid absorption and chemical processes. Fluid absorption can be affected by immersion in denture cleaners containing sodium bicarbonate. This study aims to determine the effect of a denture cleanser containing 48% sodium bicarbonate on changes in heat-cured acrylic resin's roughness. This study used 16 specimens of heat-cured acrylic resin (brand Meliodent) and was square in size of 10x10x2.0 ± 0.5 mm. The samples' roughness is measured by using Atomic Force Microscopy (AFM). The specimens were immersed in denture cleansing tablets containing 48% sodium bicarbonate for 17 days at room temperature ± 25 °C and were replaced within 8 hours. After immersion, the specimens were measured again using Atomic Force Microscopy (AFM) to determine the final roughness. The data obtained were analyzed by using paired t-test. The analysis showed no significant difference between surface roughness before and after soaking with a denture cleansing tablet containing 48% sodium bicarbonate (p 0.05). This study concluded that there was no increase in the roughness of heat-cured acrylic resin after immersion in denture cleansing tablets containing 48% sodium bicarbonateKEYWORDS: Fittydent, heat-cured acrylic resin, surface roughness


2016 ◽  
Vol 19 (3) ◽  
pp. 65
Author(s):  
Rafaela Yoshie Oliveira Kinoshita ◽  
Ricardo Sgura ◽  
Mariana Cavalcante Reis ◽  
Milton Satoiuqui Masuda ◽  
Paulo Sérgio Lopes Prazeres ◽  
...  

<p><strong>Objective</strong>: the aim of this study was to assess the effects of whitening dentifrices on the surface roughness of three commercial nanofiller-based composite. <strong>Material and Methods</strong>: two optical analyses were performed: stereomicroscopy and atomic force microscopy (AFM). Disks (8.0 diam. x 2.0 mm thick.) of the nanocomposite Z350 (3M ESPE) and two nano-hybrid composites (EsthetXHD, Dentsply and Premisa, Kerr) were submitted to <em>in vitro</em> brushing (1000 cycles) with three whitening dentifrices (Colgate Luminous White, Oral-B 3D White e Close-Up Diamond Attraction) and a control (Colgate Total12). The results were analyzed by stereomicroscopy and rated according to the following criteria: 0 – no observed roughness, 1 – average roughness, 2 – great roughness. Data was submitted to Kruskall-Wallis non-parametric test followed by Tukey test (p = 0.05). Z350 specimens were assessed by AFM. <strong>Results</strong>: the surface roughness of composites brushed with whitening dentifrices was statistically higher than the roughness found in specimens brushed with conventional dentifrice. AFM analyses showed that, at a submicrometric scale, there was an increase in the number of peaks and irregularities in specimens brushed with whitening dentifrices. <strong>Conclusion</strong>: Whitening dentifrices may have an impact on the longevity of dental composites by an increase in its roughness. It is strongly recommended that clinicians guide their patients, warning them about the risks and consequences of their use.</p><p> </p><p><strong>Keywords</strong></p><p>Abrasion; Dentifrices; Composites resin; Roughness; Whitening; Abrasive.</p>


2020 ◽  
Vol 47 (2) ◽  
pp. 188-195
Author(s):  
Choa Park ◽  
Howon Park ◽  
Juhyun Lee ◽  
Hyunwoo Seo ◽  
Siyoung Lee

This study is aimed to evaluate and compare the surface roughness and microbial adhesion to alkasite restorative material (Cention N), resin-modified glass ionomer (RMGI), and composite resin. And to examine the correlation between bacterial adhesion and surface roughness by different finishing systems.<br/>Specimens were fabricated in disk shapes and divided into four groups by finishing methods (control, carbide bur, fine grit diamond bur, and white stone bur). Surface roughness was tested by atomic force microscope and surface observation was performed by scanning electron microscope. Colony forming units were measured after incubating Streptococcus mutans biofilm on specimens using CDC biofilm reactor.<br/>Cention N surface roughness was less than 0.2 μm after finishing procedure. Control specimens of resin and Cention N specimens were significantly (<i>p</i> = 0.01) rougher. Pearson correlation coefficient (PCC = 0.13) indicated a weak correlation between surface roughness and <i>S. mutans</i> adhesion to the specimens.<br/>Compared with resin specimens, RMGI and Cention N showed lower microbial adhesion. Surface roughness and bacterial adhesion were not significantly different, regardless of the finishing systems.


Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.


2020 ◽  
Author(s):  
Benjamin P. A. Gabriele ◽  
Craig J. Williams ◽  
Douglas Stauffer ◽  
Brian Derby ◽  
Aurora J. Cruz-Cabeza

<div> <div> <div> <p>Single crystals of aspirin form I were cleaved and indented on their dominant face. Upon inspection, it was possible to observe strongly anisotropic shallow lateral cracks due to the extreme low surface roughness after cleavage. Atomic Force Microscopy (AFM) imaging showed spalling fractures nucleating from the indent corners, forming terraces with a height of one or two interplanar spacings d100. The formation of such spalling fractures in aspirin was rationalised using basic calculations of attachment energies, showing how (100) layers are poorly bonded when compared to their relatively higher intralayer bonding. An attempt at explaining the preferential propagation of these fractures along the [010] direction is discussed. </p> </div> </div> </div>


Sign in / Sign up

Export Citation Format

Share Document