Cytotoxicity of cleaning agents for ocular prostheses.

BACKGROUND: Polymethylmethacrylate (PMMA) is the most used material for the manufacturing of eye prostheses. OBJECTIVES: To investigate the cytotoxicity of different cleaning agents for ocular prostheses on human conjunctival cells. MATERIAL AND METHODS: Six groups of specimens were created (saline, soap, 4% chlorhexidine, hydrogen peroxide, 1% triclosan, and citronella oil). Three specimens were made for each disinfectant at each disinfection period (1, 7, 15, 30, 60, and 90 days), totaling 108 specimens. Thus, the specimens were disinfected, with different disinfectants, for different periods of time. After each disinfection process, the specimens were washed with sterile distilled water. A human conjunctival cell line was grown on the acrylic resin specimens and then cytotoxicity tests (MTT and Neutral Red (NR)) were performed. A negative control (untreated cell cultures) and positive control (Tween 20) were created. Two-way analysis of variance (ANOVA) and Bonferroni test were performed (p < 0.05). RESULTS: For the MTT and NR tests, when there was a significant difference between the disinfectant and negative control, the disinfectant generated a significant reduction in cell proliferation most of the time. CONCLUSIONS: All reductions in cell proliferation caused by the disinfectants were clinically acceptable. All disinfectants tested in this study were found to be non-cytotoxic to human conjunctival cells.

Effect of beverages and mouthwashes on the hardness of polymers used in intraoral prostheses.

PURPOSE: The mechanical properties of acrylic resins used in intraoral prostheses may be altered by frequent exposure to liquids such as beverages and mouthwashes. This study aimed to evaluate the effect of thermocycling and liquid immersion on the hardness of four brands of acrylic resins commonly used in removable prostheses (Onda Cryl, QC-20, Clássico, Lucitone). MATERIALS AND METHODS: For each brand of resin, seven specimens were immersed in each of six solutions (coffee, cola, red wine, Plax-Colgate, Listerine [LI], Oral B), and seven more were placed in artificial saliva (control). The hardness was tested using a microhardness tester before and after 5000 thermocycles and after 1, 3, 24, 48, and 96 hours of immersion. The results were analyzed using three-way repeated-measures ANOVA and Tukey's test (p < 0.05). RESULTS: The hardness of the resins decreased following thermocycling and immersion in the solutions. Specimens immersed in cola and wine exhibited significant decreases in hardness after immersion for 96 hours, although the greatest significant decrease in hardness occurred in specimens immersed in LI. However, according to American Dental Association specification 12, the Knoop hardness of acrylic resins for intraoral prostheses should not be below 15. Thus, the median values of superficial hardness observed in most of the acrylic resins in this study are considered clinically acceptable. CONCLUSIONS: The microhardness of polymers used for intraoral prostheses decreases following thermocycling. Among specimens immersed in beverages, those immersed in cola or wine experienced the greatest decrease in microhardness. Immersion of acrylic resins in LI significantly decreased the microhardness in relation to the initial value. Among the resins assessed, QC-20 exhibited the lowest initial hardness.

Rehabilitation of maxillary cleft with hybrid obturator prosthesis.

The hybrid obturator prosthesis aims to provide a sense of well-being to the patient, offering improvements in speech, chewing, and swallowing. Thus, the retention and stabilization of the prosthesis become decisive factors for the success of the rehabilitation treatment. The objective of this study was to describe the treatment of a 70-year-old man with a congenital maxillary cleft performed through aesthetic and functional prosthetic rehabilitation with hybrid obturator prosthesis. In this study, the fabricated prosthesis achieved its purpose by providing adequate functional and aesthetic conditions to the patient, promoting the reduction of airspace through the sealing of the oronasal communication, with consequent improvement in the quality of life.

Upper lip prosthesis retained to a palatal obturator.

In cases of total or partial maxillectomies, the prosthetic rehabilitation is an effective alternative to minimize the sequelae left by surgical resection. The present study reports a clinical case of a 52-year-old patient who underwent partial maxillectomy, with upper lip involvement. The oronasal communication, resultant from surgical resection, did not allow the patient to return to her normal social life. Besides, the upper lip partial resection damaged her face's aesthetics. The proposed treatment was the confection of an upper lip prosthesis retained by a palatal obturator. The prosthesis insertion restored the patient's facial aesthetics, contributing not only to function, but also to psychosocial adaptation.

Influence of length, diameter and position of the implant in its fracture incidence: A Systematic Review.

Background. Implant fractures can cause difficult problems for patients and dentists. This systematic review aimed to determine the influence of some implant parameters on the occurrence of their fracture and to determine the incidence of fractures reported in recent years. Methods. A search was conducted in Pubmed database, from which 12 studies published in the last 12 years were selected. Results. This review reported a 2% incidence of implant fracture. Most implants had been in function between 3 and 4 years until fracture. The studies did not provide necessary information to establish a relationship between the different parameters of implants and the incidence of fractures. Conclusion. Thus, the indication of type, diameter and length of an implant and the bone quality in the region receiving it should be studied and accurately examined for each individual case in order to avoid future failures.

Assessment of Salivary Flow and Anxiety in Patients Rehabilitated with Implant-Supported Prostheses.

BACKGROUND: The aim of this study was to verify, through self-assessment questionnaires, the influence of implant-supported prosthesis in salivary flow and anxiety of patients rehabilitated with them. MATERIALS AND METHODS: Visual analog scale (VAS) questionnaire about xerostomia and State-Trait Anxiety Inventory were applied before (T1) and after 2 days (T2) and 3 weeks (T3) of prostheses installation. The study included patients rehabilitated with implant-supported prostheses containing three or more dental elements. A total of 17 patients were evaluated. RESULTS: In VAS questionnaire, there was a significant increase in the difficulty of speaking and swallowing with dry mouth. The other VAS questions showed no statistically significant difference, indicating no changes in patients' salivary flow. CONCLUSIONS: It was concluded that the installation of implant-supported prostheses does not lead to major changes in patients' perception about their salivary flow and psychological state, causing no improvement or worsening in the characteristics evaluated.

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

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.

Expander Eye Prosthesis Assisting Ocular Rehabilitation in Child with Eye Loss.

This clinical report describes the ocular rehabilitation of a child, initially using an acrylic expander and subsequently the conventional prosthesis. A two-month-old anophthalmic female patient was referred to Araçatuba Dental School, for rehabilitation with ocular prosthesis. The treatment chosen was the manufacturing of expander prostheses changed periodically until the socket reached an adequate size, so that a definitive ocular prosthesis could be installed. The acrylic expander remained in patient's anophthalmic socket for 60 days in order to restore its volume. After this period, ocular prosthesis was installed and replaced according to facial growth. It can be observed that the expander prostheses increased the anophthalmic cavity and provided patient's adaptation for using an ocular prosthesis. The ocular prosthesis set the face aesthetic balance which eventually reflects positively on psychological and social development of the child.

Relationship Between Implant Stability Measurements Obtained by Two Different Devices: A Systematic Review.

BACKGROUND: The aim of this systematic review is to evaluate the relationship between two methods used to assess implant stability, investigating whether both provide similar implant stability assessments for the same clinical case. METHODS: A literature search was conducted on MEDLINE-PubMed and Scopus databases, without limitation of the publication period, up to November 2015. The following key words were used, with associations among them: "dental implant," "dental implants," "Osstell," "resonance frequency analysis," "implant stability quotient," "ISQ," "Periotest," "Periotest value," and "PTV." Inclusion criteria were English language, prospective, retrospective, and randomized controlled clinical trials that evaluated implant stability through use of resonance frequency analysis (RFA) and damping capacity analysis (DCA). The study should assess implant stability of only a specific region for all patients or discriminate results evaluated for each region if the analysis had been made in various regions; RFA and DCA should have been applied in the same implants and periods. Studies have been carefully selected, and data of interest were tabulated. RESULTS: Six studies met the inclusion criteria. Although there was significant numerical correlation between values obtained by both methods, data showed that less than half (46%) of cases coincided in relation to implant stability classification. CONCLUSIONS: It can be considered that there is not always a consensus and standardization in the classification of implant stability related to the values obtained by RFA and DCA devices, which could create disagreements and miscommunication among dentistry professionals.

Effect of different solutions on color stability of acrylic resin-based dentures.

The aim of this study was to evaluate the effect of thermocycling and immersion in mouthwash or beverage solutions on the color stability of four different acrylic resin-based dentures (Onda Cryl, OC; QC20, QC; Classico, CL; and Lucitone, LU). The factors evaluated were type of acrylic resin, immersion time, and solution (mouthwash or beverage). A total of 224 denture samples were fabricated. For each type of resin, eight samples were immersed in mouthwashes (Plax-Colgate, PC; Listerine, LI; and Oral-B, OB), beverages (coffee, CP; cola, C; and wine, W), and artificial saliva (AS; control). The color change (DE) was evaluated before (baseline) and after thermocycling (T1), and after immersion in solution for 1 h (T2), 3 h (T3), 24 h (T4), 48 h (T5), and 96 h (T6). The CIE Lab system was used to determine the color changes. The thermocycling test was performed for 5000 cycles. Data were submitted to three-way repeated-measures analysis of variance and Tukey's test (p<0.05). When the samples were immersed in each mouthwash, all assessed factors, associated or not, significantly influenced the color change values, except there was no association between the mouthwash and acrylic resin. Similarly, when the samples were immersed in each beverage, all studied factors influenced the color change values. In general, regardless of the solution, LU exhibited the greatest DE values in the period from T1 to T5; and QC presented the greatest DE values at T6. Thus, thermocycling and immersion in the various solutions influenced the color stability of acrylic resins and QC showed the greatest color alteration.

Influence of nanoparticles on color stability, microhardness, and flexural strength of acrylic resins specific for ocular prosthesis.

The aim of this study was to assess the effect of adding nanoparticles to N1 acrylic resin intended for artificial sclera, in terms of the color stability, microhardness, and flexural strength of the resin. Three hundred samples of N1 acrylic resin were used: 100 samples for color stability and microhardness tests (each test was performed on the opposite side of each sample), and 200 samples for flexural strength testing (100 samples before and after 1,008 hours of accelerated aging). Samples for each test were separated into ten groups (n=10), ie, without nanoparticles (control group) or with nanoparticles of zinc oxide, titanium dioxide (TiO2), and barium sulfate at weight concentrations of 1%, 2%, and 2.5% (nanoparticle groups). Data were subjected to statistical analysis with nested analysis of variance and Tukey's test (P<0.05 significance level). Among the nanoparticle groups, the TiO2 groups showed better color stability at all concentrations. Microhardness values increased after artificial aging, except for the control and zinc oxide groups. After aging, the 1%-2% TiO2 groups had significantly higher microhardness values compared with the other nanoparticle groups. Before aging, there was a significant difference in flexural strength between the control and nanoparticle groups. After aging, the control and TiO2 groups, regardless of concentration, showed the lowest flexural strength values. Incorporation of nanoparticles directly influenced the acrylic resin properties, with TiO2 being the most influential nanoparticle in terms of the evaluated properties.

Prosthetic rehabilitation of a patient with gastroesophageal reflux disease: 4-year followup.

The gastroesophageal reflux disease (GERD) is one of the main causes of dental erosion. The aim of this case presented is to describe the prosthetic rehabilitation of a patient with GERD after 4 years of followup. A 33-year-old male patient complained about tooth sensitivity. The lingual surface of the maxillary anterior teeth and the cusps of the upper and lower posterior teeth presented wear. It was suspected that the feeling of heartburn reported by the patient associated with the intake of sports supplements (isotonics) was causing gastroesophageal changes. The patient was referred to a gastroenterologist and was diagnosed with GERD. Dental treatment was performed with metal-free crowns and porcelain veneers after medical treatment of the disease. With the change in eating habits, the treatment of GERD and lithium disilicate ceramics provided excellent cosmetic results after 4 years and the patient reported satisfaction with the treatment.

Stress analysis in oral obturator prostheses: imaging photoelastic.

Maxillary defects resulting from cancer, trauma, and congenital malformation affect the chewing efficiency and retention of dentures in these patients. The use of implant-retained palatal obturator dentures has improved the self-esteem and quality of life of several subjects. We evaluate the stress distribution of implant-retained palatal obturator dentures with different attachment systems by using the photoelastic analysis images. Two photoelastic models of the maxilla with oral-sinus-nasal communication were fabricated. One model received three implants on the left side of the alveolar ridge (incisive, canine, and first molar regions) and the other did not receive implants. Afterwards, a conventional palatal obturator denture (control) and two implant-retained palatal obturator dentures with different attachment systems (O-ring; bar-clip) were constructed. Models were placed in a circular polariscope and a 100-N axial load was applied in three different regions (incisive, canine, and first molar regions) by using a universal testing machine. The results were photographed and analyzed qualitatively using a software (Adobe Photoshop). The bar-clip system exhibited the highest stress concentration followed by the O-ring system and conventional denture (control). Images generated by the photoelastic method help in the oral rehabilitator planning.

Effect of thermal cycling and disinfection on microhardness of acrylic resin denture base.

The purpose of this study was to investigate the effect of thermal cycling and disinfection on the microhardness of acrylic resins denture base. Four different brands of acrylic resins were evaluated: Onda Cryl, QC 20, Classico and Lucitone. Each brand of acrylic resin was divided into four groups (n = 7) according to the disinfection method (microwave, Efferdent, 4% chlorhexidine and 1% hypochlorite). Samples were disinfected during 60 days. Before and after disinfection, samples were thermal cycled between 5-55 °C with 30-s dwell times for 1000 cycles. The microhardness was measured using a microhardener, at baseline (B), after first thermal cycling (T1), after disinfection (D) and after second thermal cycling (T2). The microhardness values of all groups reduced over time. QC-20 acrylic resin exhibited the lowest microhardness values. At B and T1 periods, the acrylic resins exhibited statistically greater microhardness values when compared to D and T2 periods. It can be concluded that the microhardness values of the acrylic resins denture base were affected by the thermal cycling and disinfection procedures. However, all microhardness values obtained herein are within acceptable clinical limits for the acrylic resins.

Stress analysis in oral obturator prostheses over parallel and tilted implants: photoelastic imaging.

This study aimed to evaluate the stress distribution through the photoelastic method in implant-retained palatal obturators prostheses. Two photoelastic models with bucco-sinusal communication were fabricated, one model without implants and another with two parallel implants and one tilted in the molar region. A conventional obturator prosthesis and five implant-retained obturators dentures with different attachment systems were fabricated: OR, three individualized O-rings; BC, bar clip; BOC, implants splinted by bars associated with two O-rings positioned at the center of the bar; OD, implants splinted by bars associated with two O-rings positioned in distal cantilever; and BOD, implants splinted by bars with clips associated with two O-rings positioned in distal cantilever. Each assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a load of 100 N was applied on each implant. The results were obtained by observing the photographic record of the tensions in the photoelastic models resulting from the application of load. It can be observed that a larger amount of stress fringes on BC system. It was concluded that the attachment system has a direct influence on the stress distribution of implant-retained obturator prostheses, with the three individualized O-rings exhibiting the lowest stress values, and tilted implants presented a biomechanical behavior similar to parallel implants.

Chromatic changes to artificial irises produced using different techniques.

Ocular prostheses are important determinants of their users' aesthetic recovery and self-esteem. Because of use, ocular prostheses longevity is strongly affected by instability of the iris color due to polymerization. The goal of this study is to examine how the color of the artificial iris button is affected by different techniques of artificial wear and by the application of varnish following polymerization of the colorless acrylic resin that covers the colored paint. We produce 60 samples (n = 10) according to the wear technique applied: conventional technique without varnish (PE); conventional technique with varnish (PEV); technique involving a prefabricated cap without varnish (CA); technique involving a prefabricated cap with varnish (CAV); technique involving inverted painting without varnish (PI); and technique involving inverted painting with varnish (PIV). Color readings using a spectrophotometer are taken before and after polymerization. We submitted the data obtained to analyses of variance and Tukey's test (P < 0.05). The color test shows significant changes after polymerization in all groups. The PE and PI techniques have clinically acceptable values of ΔE, independent of whether we apply varnish to protect the paint. The PI technique produces the least color change, whereas the PE and CA techniques significantly improve color stability.

Retention and processing methods of nasal prosthesis.

Patients with congenital malformations, traumatic or pathological mutilation and maxillofacial developmental disorders can be restored aesthetically and emotionally by the production and use of facial prostheses. The aim of this study was to review the literature about the retention and processing methods of facial prostheses, and discuss their characteristics. A literature review on Medline (PubMed) database was performed by using the keywords "maxillofacial prosthesis, silicone, esin, pigment, cosmetic, prosthetic nose", based on articles published from 1956 to 2010. Several methods of retention, from adhesives to the placement of implants, and different processing methods such as laser, CAD/CAM and rapid prototyping technologies have been reported. There are advantages and disadvantages of each procedure, and none can be classified as better compared to others.

A utilização de abutment de zircônia na reabilitação oral: aspectos protéticos e periodontais / Zirconia abutment on implant fixed reconstructions: prosthetic and periodontal aspects

Os abutments de zircônia são utilizados para obter resultados estéticos satisfatórios em reabilitações anteriores de próteses sobre implantes quando os componentes de titânio causam coloração acinzentada na gengiva peri-implantar. Contudo, a literatura não possui um consenso no que diz respeito a estabilidade deste tecido em contato com abutments de zircônia. Dessa forma, o objetivo do presente estudo foi relatar o caso de uma paciente reabilitada com uma coroa cerâmica implanto-retida sobre abutment de zircônia, após 3 anos de acompanhamento. Paciente do sexo feminino de 47 anos de idade foi admitida na clínica odontológica da Faculdade de Odontologia de Araçatuba queixando-se de uma fratura em sua coroa unitária implanto-retida na região do elemento 22. A mesma optou pela troca da prótese que apresentava fratura por outra total cerâmica. Após 3 anos de acompanhamento, pode-se observar a manutenção do resultado estético e a estabilidade do tecido mole periimplantar, sem a presença de inflamações ou recessão. Dentro das limitações de um relato de caso, conclui-se que a utilização de abutment de zircônia é uma maneira eficaz de reabilitação, preservando a estética e a função através da manutenção dos tecidos

Zirconia abutments are used to obtain satisfactory aesthetic results in implant fixed anterior prostheses when metal abutments promote a grayish mucosal discoloration of the peri-implant soft tissues. However, there is a lack of studies to confirm the clinical performance of the peri-implant soft tissues surrouding zirconia abutments. This study described a case report of a patient treated with implant fixed all-ceramic crown made out on zirconia abutment after 3 years of followup. A 47-year-old female patient was admitted to the dental clinic (Aracatuba Dental School) complaining about the fracture of her implant fixed single crown in the region of the left lateral incisor. The patient chose the replacement of the fractured prosthesis for an allceramic crown. After 3 years of follow-up it was observed that maintenance of the aesthetic results and the peri-implant soft tissue without any inflammation or gingival recessions. Within the limitations of a case report, it can be conclude that zirconia abutments is a effective rehabilitation treatment because it preserves the aesthetics and function through the maintenance of peri-implant tissues

Influência da rugosidade de superfície e ação de diferentes desinfetantes na formação de biofilme em resina acrílica para prótese ocular e sua biocompatibilidade em contato com células da conjuntiva humana / Influence of surface roughness and action of different disinfectants on the formation of biofilm in acrylic resin for ocular prosthesis and their biocompatibility in contact with cells human conjunctiva cells

O controle da formação de biofilme é essencial para manter a saúde da cavidade anoftálmica dos portadores de prótese ocular. As propriedades físicas da resina acrílica, como a sua rugosidade, podem interferir na adesão de microrganismos nas próteses e na formação de biofilmes. Sendo assim, é necessário utilizar soluções de limpeza eficazes e que não causem irritação tecidual na conjuntiva ocular. O objetivo desse trabalho foi verificar a influência da rugosidade de superfície da resina acrílica utilizada na confecção de próteses oculares na formação de biofilme bacteriano, bem como avaliar a eficácia antimicrobiana e citotoxicidade de diferentes soluções para desinfecção de próteses oculares. Para a análise da rugosidade, corpos de prova de resina acrílica foram confeccionados e divididos em 5 grupos de acordo com a granulação de lixa de polimento utilizada: 120, 400, 800, 1200 e 1200S (lixa + sílica). A rugosidade dos corpos de prova foi mensurada por meio de perfilômetro e imagens de Microscopia de Força Atômica foram obtidas para cada grupo. O crescimento das espécies Staphylococcus aureus e Staphylococcus epidermidis sobre os corpos de prova foi avaliado após 4 e 24h, por meio da contagem das Unidades Formadoras de Colônia (UFC)/mL. O efeito dos seguintes tratamentos: soro fisiológico, sabão neutro, clorexidina 4%, pastilhas efervescentes Efferdent®, triclosan 1% e citronela sobre biofilme formado sobre os corpos de prova de resina acrílica também foi avaliado por meio da determinação do número de UFC/mL. A citotoxicidade dos agentes antimicrobianos foi avaliada por meio dos testes de MTT e Neutral Red, após tratamento dos corpos de prova, diariamente, por 1, 7, 15, 30, 60 e 90 dias com as soluções já citadas, sendo avaliados ao fim de cada período. Os dados obtidos foram submetidos à análise estatística adequada, considerando se provinham de dados paramétricos ou não paramétricos. Os resultados demonstraram que os menores valores de rugosidade foram encontrados no grupo 800, 1200 e 1200S. A contagem microbiana foi menor no grupo 1200S e esta diferiu estatisticamente (p>0,05) do controle para ambos os tempos de avaliação e bactérias. Na análise da ação antimicrobiana das soluções para desinfecção, todos os protocolos promoveram redução do crescimento dos microrganismos testados comparados ao controle (crescimento sem a presença do antimicrobiano), sendo que os grupos submetidos ao tratamento com clorexidina 4%, pastilhas efervescentes Efferdent® e triclosan 1% eliminaram o biofilme (p>0,01). Ainda nos ensaios de citotoxicidade, em todos os grupos foi observada proliferação celular das células da conjuntiva acima de 84% (p>0,05). Dessa forma, conclui-se que a rugosidade não interfere significativamente na adesão bacteriana e formação de biofilme, exceto para o grupo 1200S, e que os protocolos de limpeza com imersão em clorexidina 4%, pastilhas efervescentes Efferdent® e triclosan 1% são totalmente eficazes na desinfecção e não apresentam citotoxicidade para com as células da conjuntiva humana, sugerindo sua indicação para desinfecção de próteses oculares(AU)

The control of biofilm formation is essential to maintain the health of anophthalmic cavity of ocular prosthesis wearers. The physical properties of the acrylic resin, such as surface roughness, may interfere with the adhesion of microorganisms to the prostheses. Therefore, it is necessary to use cleaning solutions that are effective and do not cause tissue irritation in ocular conjunctiva. The aim of this study was to verify the influence of surface roughness of the acrylic resin used in the preparation of ocular prosthesis in the formation of bacterial biofilm, as well as to evaluate the antimicrobial efficacy and cytotoxicity of different disinfectants in ocular prostheses. For roughness analysis, acrylic resin samples were prepared and divided into 5 groups according to the granulation of polishing sandpaper used: 120, 400, 800, 1200 and 1200S (sandpaper + silica). The roughness of the samples was measured using a profilometer and Atomic Force Microscopy images were obtained for each group. The microbial growth for Staphylococcus aureus and Staphylococcus epidermidis on the samples was evaluated after 4 and 24 h by counting the Colony Forming Units (CFU)/mL. The effect of the following solutions was also evaluated by CFU/mL: non treated group (immersed in saline solution), neutral soap, 4% chlorhexidine, Efferdent® effervescent tablets, 1% triclosan and citronella. The cytotoxicity of the solutions was evaluated by MTT and Neutral Red after treating the samples daily for 1, 7, 15, 30, 60 and 90 days with the solutions already mentioned, being evaluated at the end of each period. Data were submitted to proper statistical analysis, considering whether data were parametric or non-parametric. The results showed that the lowest roughness values were found in groups 800, 1200 and 1200S. 1200S group also presented the lowest values of microbial growth statistically different from control group (p>0,05), for both periods and bacteria evaluated. In the analysis of the solutions, compared to the control group (microbial growth without the presence of the antimicrobial), all protocols promoted a reduction in the growth of the microorganisms, and the groups submitted to disinfection with 4% chlorhexidine, Efferdent® effervescent tablets and 1% triclosan eliminated the biofilm (p>0,01). In addition, all groups showed cell proliferation of conjunctival cells above 84% in the cytotoxicity assays (p>0,05). Thus, it was concluded that the roughness does not significantly interfere in the adhesion of the microorganisms, except for group 1200S, and that the cleaning protocols with 4% chlorhexidine, Efferdent® effervescent tablets and 1% triclosan are totally effective in the disinfection and do not present cytoxicitiy with human conjunctive cells, what suggests their indication for cleaning of ocular prosthesis(AU)

Influência da adição de nanopartículas na estabilidade de cor, microdureza e resistência à flexão de resina específica para confecção de próteses oculares / The influence of nanoparticles addition on color stability, microhardness and flexural strength of acrylic resin specific for ocular prosthesis

Uma alternativa segura para reabilitar pacientes com anoftalmia é a utilização de próteses oculares. O conhecimento das propriedades físicas e mecânicas da resina acrílica utilizada na confecção destas próteses é de suma importância. Nanopartículas vêm sendo adicionadas à cadeia polimérica das resinas com o objetivo de melhorar essas propriedades. Assim, o propósito desse estudo foi avaliar a influência da adição de nanopartículas na estabilidade de cor, microdureza e resistência à flexão da resina acrílica N1 específica para confecção da esclera artificial. Para isso, foram confeccionadas 300 amostras. As nanopartículas utilizadas foram Óxido de Zinco (ZnO), Dióxido de Titânio (TiO2) e Sulfato de Bário (BaSO4), nas concentrações de 1, 2 e 2,5%. As amostras foram distribuídas em 10 grupos (n=30) de acordo com o tipo e concentração de nanopartícula associada à resina acrílica N1: controle - sem nanopartícula (C), óxido de zinco 1% (ZnO 1%), óxido de zinco 2% (ZnO 2%), óxido de zinco 2,5% (ZnO 2,5%), dióxido de titânio 1% (TiO2 1%), dióxido de titânio 2% (TiO2 2%), dióxido de titânio 2,5% (TiO2 2,5%), sulfato de bário 1% (BaSO4 1%), sulfato de bário 2% (BaSO4 2%), sulfato de bário 2,5% (BaSO4 2,5%). Os ensaios de leitura de cor, microdureza e resistência à flexão foram realizados antes e após 1008 horas de envelhecimento acelerado. Os dados obtidos foram submetidos à análise estatística, utilizando-se os testes de nested ANOVA e teste de Tukey. Os resultados demonstraram que, comparando-se as diferentes nanopartículas, os grupos com TiO2 apresentaram melhor estabilidade de cor, para todas as concentrações. Em relação ao teste de microdureza, com exceção dos grupos C e com adição de óxido zinco, os valores de microdureza aumentaram após envelhecimento, sendo que, nas concentrações de 1 e 2%, os grupos com TiO2 apresentaram os maiores valores, com diferença estatística significante em relação às outras nanopartículas. Considerando-se a resistência à flexão, no...

A safe, aesthetic and satisfactory alternative to rehab patients with anofthalmia is the use of ocular prosthesis. It is very important to know about the physical and mechanical properties of the acrylic resin used on this prosthesis production. Nanoparticles have been added to the acrylic resins polymeric chain in order to improve these properties. So, this study aims to assess the influence of nanoparticles addition on the color stability, microhardness, and flexural resistance of artificial sclera N1 acrylic resin. To this purpose, 300 samples were made. The nanoparticles used were Zinc Oxide (ZnO), Titanium Dioxide (TiO2) and Barium Sulfate (BaSO4), at the concentrations of 1, 2 and 2%. Samples were divided into 10 groups (n=30), according to the nanoparticle and concentration associated with the resin: control – without nanoparticle (C); zinc oxide 1% (ZnO 1%) ; zinc oxide 2% (ZnO 2%); zinc oxide 2,5% (ZnO 2,5%); titanium dioxide 1% (TiO2 1%); titanium dioxide 2% (TiO2 2%); titanium dioxide 2,5% (TiO2 2,5%); barium sulfate 1% (BaSO4 1%), barium sulfate 2% (BaSO4 2%); barium sulfate 2,5% (BaSO4 2,5%). The color stability, microhardness and flexural resistance tests were performed before and after 1008 hours of accelerated aging. Data were subjected to statistical analysis using nested ANOVA and Tukey test. The results showed that, comparing the different nanoparticles, the groups with TiO2 showed better color stability at all concentrations. Microhardness values increased after artificial aging, except for groups C and ZnO and groups with TiO2 at 1 and 2% showed the highest statistically significant values compared with the other nanoparticles. Regarding flexural strength, at initial period, there was statistically significant difference between control group and the other groups. By comparing the periods, the C group and with TiO2 showed statistically significant lowest flexural strength values after aging, regardless concentration. It is concluded that…