Analysis of physical properties of facial silicones with different pigmentations submitted to nonthermal plasma treatment and accelerated aging.

STATEMENT OF PROBLEM: Exposure of silicone prostheses to environmental factors can alter their properties, affecting longevity. However, whether nonthermal plasma (NTP) can prevent these alterations is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the surface roughness (Ra), sorption, solubility, and color stability (ΔE00) of the MDX4-4210 and A-120 silicones, with and without NTP treatment in accordance with an independent analysis of the use of 2 pigmentations. MATERIAL AND METHODS: One hundred sixty specimens were fabricated and distributed into 16 groups (n=10) as per the silicone, pigmentation, and NTP coating. The NTP was applied, and the Ra, sorption, solubility, and ΔE00 were evaluated before and after accelerated aging. ANOVA was used, and the HSD Tukey test was applied (α=.05). RESULTS: NTP generated an increase in roughness after aging, regardless of pigmentation or silicone. A-120 silicone without NTP showed a reduction in roughness after aging, regardless of pigmentation. For sorption and solubility, the bronze pigmentation (for A-120 and MDX4-4210) presented the smallest results after NTP treatment. For MDX4-4210 with pink pigmentation and NTP, sorption decreased and solubility increased. For A-120 with pink pigmentation and NTP, sorption and solubility increased. Sorption was reduced in all situations, except for A-120 with pink pigmentation, which increased. Regardless of the silicone used, solubility was reduced after NTP for bronze pigmentation. For A-120 and MDX4-4210 with pink pigmentation and NTP, the solubility increased. For both pigmentations, the NTP treatment promoted lower color alteration only for the A-120 silicone after accelerated aging (within the acceptability threshold). CONCLUSIONS: The NTP protocol of this study, which was applied to facial silicones, generated inconsistent results between the evaluated properties. Therefore, the NTP protocol used does not seem to be ideal for the treatment of silicone surfaces after aging.

Análise de diferentes propriedades físicas e ópticas de silicones faciais, com diferentes pigmentos, submetidos ao tratamento com plasmas de baixa temperatura e ao envelhecimento acelerado / Analysis of different properties of two maxillofacial silicone, with different pigmentation, submitted to the treatment with nonthermal plasma and accelerated aging

Contexto: Os materiais para confecção de próteses bucomaxilofaciais estão em constante necessidade de aprimoramento, devido a sua curta longevidade. Novos matérias e metodologias necessitam ser testados para solucionar tal defasagem. Objetivo: Avaliar a estabilidade cromática, sorção e solubilidade e rugosidade dos elastômeros MDX4-4210 e A-120, utilizados na confecção de próteses maxilofaciais. Avaliou-se a influência do plasma de baixa temperatura (PBT), a presença de pigmento (dois tipos de pigmentos inorgânicos) e o envelhecimento acelerado. Materiais e métodos: Foram confeccionadas 160 e divididas em 16 grupos (n=10), de acordo com o tipo de silocone, pigmento e uso ou não do PBT. O plasma aplicado apresenta uma composição de 70% hexametildisiloxano, 20% O, and 10% Ar. Foi avaliado a estabilidade cromática, a rugosidade superficial (Ra), e sorção e solubilidade dos silicones antes e após envelhecimento. Resultados: O silicone A-120 apresentou melhores resultados de estabilidade cromática, que foi influenciada pela aplicação do plasma (P<0,001), A-120 com plasma (ΔE=1,13) com pigmento bronze e A-120 com plasma (ΔE=1,01) com pigmento orbipasta. A rugosidade apresentou diferença entre os silicones e o tempo (P< 0,001) com valores de Ra entre 0,14nm e 0,39 nm, o grupo com menor rugosidade foi do silicone A-120 com plasma. A sorção e solubilidade foi diferente entre os pigmentos avaliados, os grupos com pigmento bronze apresentaram menor sorção e solubilidade após aplicação do plasma (P<0,001). Conclusão: O plasma é uma opção para melhorar as propriedades dos silicones faciais(AU)

Statement of problem: The manufacturing materials of maxillofacial prostheses are in constant need of improvements due its poor longevity. Aim: Evaluate the chromatic stability, surface roughness and sorption and solubility of two silicones, MDX4-4210 and A-120 with two intrinsic pigments and the application of a nonthermal plasma (NTP). Methods: One-hundred and sixty specimens were fabricated and distributed into 16 groups (n=10) according to the silicone, pigment and plasma coat. The NTP was applied with a mixture of 70% hexamethyldisiloxane, 20% O, and 10% Ar. The chromatic stability, surface roughness (Ra) and sorption and solubility were evaluated. Results: A-120 presented better chromatic stability results, which were influenced by the NTP (P<0,001); group A-120 with bronze pigment (ΔE=1,13) and A-120 with orbipasta pigment (ΔE=1,01) were the best results. Surface roughness presented a difference for period and group (P<0,001) with Ra ranging from 0,14nm to 0,39 nm; the least rough result was from A-120 with NTPS. Sorption and solubility were different for the pigments, the bronze pigment groups presented the smallest results after NTP treatment (P<0,001). Conclusion: NTP is a viable option to improve physical properties of maxillofacial silicones(AU)

Effect of nanoscale particles incorporation on microhardness of polymers for oral prosthesis.

OBJECTIVES: This study aimed to evaluate the influence of the incorporation of pigments on surface hardness of four acrylic resins subjected to thermocycling and analyze their elemental composition using energy dispersive X-ray spectroscopy (EDS). MATERIALS AND METHODS: Twenty-one discs of each resin were fabricated, whereas seven had no additive, seven had 3% of nanoscale pigments and last seven had 10% of them. The percentage was obtained by measuring the total weight of each resin disc. Besides, seven discs composed by only nanoscale pigments were also fabricated, totalizing 91 discs. The pigment was weighed by using an analytical balance (BEL Analytical Equipment, SP, Brazil). The surface hardness was measured through a hardness tester machine before and after thermocycling (5-55°C, for 2000 cycles). Data were analyzed by ANOVA and Tukey's test (P < 0.05). The chemical composition of the discs composed only by nanoscale pigments was analyzed with EDS test. RESULTS: Hardness of all resins decreased after thermocycling. The lowest values were observed on the discs with 3% of nanoscale pigments and discs fabricated only with them. EDS showed the presence of titanium dioxide. CONCLUSION: Discs with 7% of pigments (after thermocycling) showed higher hardness values.

Antimicrobial activity of conventional and plant-extract disinfectant solutions on microbial biofilms on a maxillofacial polymer surface.

STATEMENT OF PROBLEM: Dentists often note problems with infection in patients with maxillofacial prostheses. Conventional disinfection protocols are not always effective and may alter the properties of the polymer used in the prosthesis. Thus, the search for improved disinfection methods is important. PURPOSE: The purpose of this in vitro study was to evaluate and compare the antimicrobial activity of conventional disinfectant solutions (water and neutral soap and 4% chlorhexidine) and plant extracts (Cymbopogon nardus and Hydrastis canadensis) on specimens of maxillofacial silicone contaminated with Candida albicans and Staphylococcus aureus biofilms. MATERIAL AND METHODS: Seventy-two silicone (MDX4-4210) specimens were fabricated (5×2 mm) and sterilized. Thirty-six were contaminated with C albicans (10(6) cells/mL) and 36 with S aureus (10(8) cells/mL) to evaluate the antimicrobial activity of the cleaning protocols. After incubation (37°C/72 hours), the specimens were divided into 5 groups: not disinfected (positive control), soaking in saline solution for 10 minutes, soaking in 4% chlorhexidine for 10 minutes, soaking in C nardus for 10 minutes, soaking in H canadensis for 10 minutes, and washing by hand with water and neutral soap for 30 seconds. The viability of cells was evaluated by XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay and by scanning electron microscope analysis. The results were analyzed by ANOVA and the Tukey HSD test (α=.05). RESULTS: All disinfection solutions provided a statistically significant reduction in biofilm viability compared with the control group for both microorganisms (P<.05). Washing with water and neutral soap was significantly more effective in reducing biofilm viability than immersion in the disinfection solutions, with persistence of viable microorganisms between 1.05% for C albicans and 0.62% for S aureus after this cleaning protocol. Photomicrographs revealed that 4% chlorhexidine altered the surface of the polymer. CONCLUSIONS: Within the limitations of this in vitro study, it was concluded that the cleaning protocols with different disinfectant solutions produced a significant reduction in the viability of C albicans and S aureus biofilms on the silicone polymer. Washing with water and neutral soap was the most effective protocol against both microorganisms.

Comparison of conventional and plant-extract disinfectant solutions on the hardness and color stability of a maxillofacial elastomer after artificial aging.

STATEMENT OF PROBLEM: Silicone elastomers undergo physical and chemical degradation with disinfecting solutions. Phytotherapy may be a suitable solution for disinfection. However, its effect on the properties of the silicone material is unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effect of disinfection with conventional and plant-extract solutions and of artificial aging on the hardness and color stability of a facial silicone associated with pigments and an opacifier. MATERIAL AND METHODS: Four hundred specimens of silicone (MDX4-4210) were fabricated (5×6 mm). Two pigment shades and 1 dry opacifier were combined in the tested material, and 4 groups (n=10) were obtained: colorless (GI), colorless with opacifier (GII), medium pigment with opacifier (GIII), and black pigment with opacifier (GIV). Specimens were subjected to disinfection (30 days) using saline solution, water, and neutral soap (digital friction, 30 seconds), chlorhexidine 4%, Hydrastis canadensis, and Cymbopogon nardus extracts (immersion, 10 minutes). Shore A hardness (ASTM D2240) and color analyses were performed before and after disinfection. Specimens were then exposed to 1008 hours of artificial aging (ASTM 53) and subjected to final hardness and color readings. The results were analyzed with ANOVA and the Tukey significant difference test (α=.05). RESULTS: The opacifier increased the hardness (GII). For GII, the H. canadensis solution and the friction with water and soap promoted significantly reduced hardness; the friction also promoted a reduction in this property for GIV. The GIII was not affected after disinfection. A significant difference was found between the ΔE values of the specimens disinfected with H. canadensis, C. nardus, and chlorhexidine, and specimens subjected to saline solution and neutral soap. CONCLUSION: The hardness of MDX4-4210 after the experimental procedure was considered clinically acceptable for facial prostheses. All groups showed clinically unacceptable color alterations regardless of the disinfecting solution.

Reabilitação estética e funcional de dentes anterioriores, utilizando prótese cimentada: relato de caso / Beauty and functional rehabilitation of previous tooth, using the system cast intermediate ucla: case report

O objetivo deste trabalho é relatar um caso de reabilitação com pilar protético do tipo UCLA fundido metálico com prótese cimentada, para um implante com angulação acentuada na região maxilar anterior perfazendo o ponto de contato a um dente reabilitado ambos utilizando o sistema de cerâmica pura IPS e.max. Apresentação do Caso: Paciente do sexo masculino chegou ao consultório insatisfeito com a estética do seu sorriso. Este apresentava implante com plataforma hexágono externo (3.75x11. 5 mm) no elemento 22, com grau de angulação para vestibular acentuado,ocasionando um desconforto visual ao sorriso do paciente. Dessa forma optou- se pela utilização de um pilar protético do tipo UCLA fundido, para corrigir a posição e retificar o perfil de emergência do implante. O sistema de cerâmica pura IPS e.max foi utilizado como material de revestimento estético para a prótese sobre implante do dente 22 epara o elemento 23, que possui uma prótese parcial fixado tipo coroa total. A estrutura de montagem da cerâmica foi realizada e, após o consentimento do paciente, a prótese foi finalizada e instalada. Conclui-se que a reabilitação estética foi muito satisfatória e que esse tipo de reabilitação pode ser indicado para situações mais complexas

This study to report case of rehabilitation with a prosthetic abutment type cast UCLA, for an implant with sharp angle in the anterior maxilla region, along with a ceramic system IPS e.max. Case presentation: A male patient came to office dissatisfied with aesthetics your smile. This presented implant with external hexagon platform (3.75x11. 5 mm) in element 22, with degree of angulation for sharp buccal, causing visual discomfort to the patient’s smile. It chose this way by the use of a prosthetic pillar-type cast UCLA, to correct the position and rectify the emergence profile of the implant. The ceramic system IPS e.max was used as coating for aesthetics the prosthesis material on tooth implant 22 e to the element 23, which has a fixed partial denture type full crown. The ceramic structure assembly was performed, and after the consent of the patient, the prosthesis is finished and installed

Prótese parcial removível obturadora - uma reabilitação oral que devolve o bem-estar físico e mental / Removable partial denture obturator - an oral rehabilitation that restores physical and mental well-being

As deformidades bucomaxilofaciais são constrangedoras e embaraçosas ao portador. Estes pacientes apresentam-se com sérios problemas psíquicos, familiares e sociais tornando-se indivíduos traumatizados, complexados e diminuídos física e psicologicamente. As causas dessas deformidades podem ser congênitas, causadas por más formações/distúrbios de desenvolvimento, ou adquiridas, causadas por mutilações de origem patológica, como as doenças necrosantes e as oncologias cirúrgicas, ou traumáticas, como acidentes de trabalho, trânsito e intencionais.

Maxillofacial deformities may cause awkward and embarrassing bearer. These patients present serious psychological, family and social issues becoming traumatized and complexed. These deformities can have congenital origin, malformations and developmental disorders, or can be caused by pathological mutilation such as necrotizing diseases and surgical oncology, or traumas such as traffic and work accidents

Técnicas de reembasamento para prótese total / Techiques for relining complete denture

A reabsorção óssea alveolar é contínua ao longo da vida dos pacientes edêntulos, podendo gerar desadaptação das próteses durante a fala e mastigação. Uma alternativa para esta desestabilização é reembasamento da prótese, uma manobra que visa readaptar a base da prótese ao rebordo por meio da adição de uma camada de material compatível à superfície interna da prótese. Este procedimento pode ser direto, quando realizado no consultório, ou indireto quando confeccionado em laboratório protético. O objetivo deste estudo é apresentar as técnicas dos dois tipos de reembasamento para prótese total

Alveolar bone resorption is continuous throughout the life of edentulous patients, the prosthesis mismatch can generate during speech and chewing. An alternative to this would be to destabilize the denture reline, a maneuver which aims to readjust the denture base to the rim by the addition of a plastic film to the inner surface of the prosthesis material. This procedure may be direct, when performed in the clinic, or indirect when made in prosthetic laboratory. The aim this study is to demonstrate the technical of two reline for denture

Reabilitação protética implantossuportada em região anterior maxilar com utilização de gengiva artificial cerâmica: relato de caso / Implant-supported prosthetic rehabilitation in maxillary anterior region with gingival-colored ceramic: case report

Os implantes osseointegrados trouxeram um grande avanço na área de reabilitação oral. Porém essa reabilitação pode ser dificultada devido às condições anatômicas, principalmente em regiões maxilares anteriores, onde se necessita de uma maior estética. O objetivo do estudo é relatar um caso onde foi necessária a utilização de intermediários angulados com a finalidade de permitir o correto posicionamento da prótese, e reconstrução protética com gengiva artificial cerâmica para proporcionar o melhor resultado estético ao paciente. O resultado estético e funcional forneceu ao paciente uma maior satisfação com seu sorriso. Um correto planejamento é essencial para que possa fornecer ao paciente o melhor resultado estético e funcional, sendo necessária a utilização de alguns componentes para se chegar ao melhor resultado, como a utilização de intermediários e gengivas artificiais

The osseointegrated implants created a progress in oral rehabilitation. But this rehabilitation may be complicated by anatomical conditions, mainly in maxillary anterior region, where a higher aesthetic is required. The aim of study was to report one case which the use of angled abutments were necessary to allow the correct positioning of the prosthesis and also the prosthetic reconstruction with gingival-colored ceramic to provide best aesthetic result for patient. The aesthetic and functional results provided greater patient satisfaction with her smile. The correct planning is essential to provide to patient the best aesthetic and functional results, being necessary the use of abutments and gingival-colored ceramic to reach better results