Evaluation of the biocompatibility of silicone gel implants - histomorphometric study

Breast implants are medical devices that are used to augment breast size or to reconstruct the breast following mastectomy or to correct a congenital abnormality. Breast implants consist of a silicone outer shell and a filler (most commonly silicone gel or saline). Approximately 5 to 10 million women worldwide have breast implants. Histomorphometric study to evaluate the biological tissue compatibility of silicone implants suitable for plastic surgery and the adverse effects and risks of this material. Thirty Wistar white rats received subcutaneous implants and the revestiment of silicone gel Silimed ®®, and randomized into six groups of five animals each, according to the type of implanted material and the time of sacrifice. Eight areas of 60.11mm2 corresponding to the obtained surgical pieces were analyzed, counting mesenchymal cells, eosinophils, and foreign body giant cells, observing an acceptable biocompatibility in all implants, for subsequent statistical analysis by Tukey test. Silicone gel showed inflammation slightly greater than for other groups, with tissue reactions varying from light to moderate, whose result was the formation of a fibrous capsule around the material, recognized by the organism as a foreign body. Despite frequent local complications and adverse outcomes, this research showed that the silicone and top layer presented an acceptable chronic inflammatory reaction, which did not significantly differ from the control group. In general, it is possible to affirm that silicone gel had acceptable levels of biocompatibility, confirmed the rare presence of foreign body giant cells, and when of the rupture, formed a fibrous capsule around the material, separating the material of the organism. © AVICENA 2013.

Evaluation of the Shore A Hardness of Silicone for Facial Prosthesis as to the Effect of Storage Period and Chemical Disinfection

The failure of facial prostheses is caused by limitations in the properties of existing materials, especially flexibility and durability. Therefore, this study evaluated the Shore A hardness of silicone used for fabrication of facial prostheses, Silastic MDX4-4210, according to the influence of storage period, daily disinfection, and 2 types of pigmentation. Thirty specimens were fabricated and divided in 3 groups: colorless, pigmented with makeup, and pigmented with iron oxide. Analysis of results was assessed on a Shore A hardness meter immediately, 6 months, and 1 year after fabrication of specimens, following the guidelines of the American Society for Testing and Materials. The hardness values were statistically analyzed by the Tukey test. The silicone exhibited an increase in hardness with time. However, the hardness was stable from 6 months to 1 year. It was concluded that the silicone is within the values of Shore A hardness reported in the literature, regardless of the storage period, pigmentation, and chemical disinfection.

Marginal deterioration of the silicone for facial prosthesis with pigments after effect of storage period and chemical disinfection

The failure of facial prostheses is caused by limitations in the properties of existing materials, especially flexibility and durability. Therefore, this study evaluated the marginal deterioration of a silicone used for fabrication of facial prostheses (Silastic MDX4-4210, Dow Corning Corporation, Midland, MI, USA) according to the influence of artificial aging, daily disinfection, and 2 types of pigmentation. Thirty specimens were fabricated and subdivided in 6 groups: without pigmentation, pigmented with make-up powder and iron oxide, and evaluated with and without the action of the disinfectant. Analysis of marginal deterioration was performed on a scanning electron microscope (magnification, ×5000) immediately 6 months and 1 year after fabrication of specimens, following the guidelines of ASTM International. After visual analysis of the photomicrographs, it was noticed that all groups presented marginal deterioration and alterations in surface texture with time. The use of disinfection did not contribute to the marginal deterioration of polymer (silicone), regardless of the pigmentation and artificial aging.

Implant-retained thumb prosthesis with anti-rotational attachment for a geriatric patient

This report presents the use of a dental implant with an anti-rotational attachment for the retention of a thumb prosthesis. A retention system was manufactured with an attachment (UCLA) screwed into the implant with a two-bar system that was cast in metallic silver palladium. A substructure made from heat-cured acrylic resin was joined to the retention system by clips to join the thumb to the finger (bar clip) in the cast with implant rejoinder. The silicone material, Silastic-MDX 44210, was used to achieve function and aesthetics. Following osseointegration, no skin problems were observed. Whilst the implant-retained digital prosthesis presented some motor limitations, it allowed the patient to return to entertainment and achieve social conviviality.

Prosthesis Auricular With Osseointegrated Implants and Quality of Life

Implants in craniofacial reconstructions improve prostheses retention and stability, comfort, and safety for the patient. According to biomechanical principles, the treatment success regarding osseointegration maintenance depends on an adequate surgery technique associated to a retention system that provides favorable tension distribution to implants. Implants in the mastoid area are a very important aid for retention of auricular prostheses. Color stability of resin and silicone is an important factor for longevity of auricular prostheses, and the high degree of satisfaction of patients with head and neck defects receiving epithesial reconstruction in the maxillofacial region is demonstrated.

Rehabilitation with ear prosthesis linked to osseointegrated implants

Background: The absence of an ear, which can be the result of a congenital malformation, surgical tumour resection or traumatic injury, is a significant aesthetic problem. Attachment of ear prostheses with adhesives can cause local irritation for the wearer and affect the colour of the prostheses. Use of implants in craniofacial reconstruction can improve the retention and stability of prostheses giving to patient greater comfort and security relative to adhesive attachment.Objective: The aim of this report was to present a clinical case of a mutilated patient who was rehabilitated by means of installing an ear prosthesis fixed through osseointegrated implants.Materials and methods: The patient had two implants installed in the mastoid region that were linked by a bar, and a clip-type system was used. The ear prosthesis was constructed from medical-use silicone, pigmented to match the patient's skin colour and linked to the retention system.Conclusion: The patient's rehabilitation was satisfactory from both a functional and an aesthetic point of view, making it possible for the patient to return to a normal social life and regain lost self-esteem.

Effect of Chemical Disinfection and Accelerated Aging on Color Stability of Maxillofacial Silicone with Opacifiers

Purpose: The purpose of this study was to evaluate the color stability of MDX4-4210 maxillofacial elastomer with opacifier addition submitted to chemical disinfection and accelerated aging.Materials and Methods: Ninety specimens were obtained from Silastic MDX4-4210 silicone. The specimens were divided into three groups (n = 30): Group I: colorless, Group II: barium sulfate opacifier, Group III: titanium dioxide opacifier. Specimens of each group (n = 10) were disinfected with effervescent tablets, neutral soap, or 4% chlorhexidine gluconate. Disinfection was conducted three times a week for 2 months. Afterward, the specimens were submitted to different periods of accelerated aging. Color evaluation was carried out after 60 days (disinfection period) and after 252, 504, and 1008 hours of accelerated aging, using a reflection spectrophotometer. Color alterations were calculated by the CIE L*a*b* system. Data were analyzed by three-way ANOVA and Tukey test (alpha = 0.05).Results: Group II exhibited the lowest color change, whereas Group III the highest (p < 0.05), regardless of the chemical disinfection and accelerated aging periods.Conclusion: Opacifier addition, chemical disinfection, and accelerated aging procedures affected the color stability of the maxillofacial silicone.

Bond strength between acrylic resin and maxillofacial silicone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Pigments and Opacifiers on Color Stability of an Artificially Aged Facial Silicone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Disinfection and Accelerated Aging on Color Stability of Colorless and Pigmented Facial Silicone

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Color Stability Comparison of Silicone Facial Prostheses Following Disinfection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Color Stability of Polymers for Facial Prosthesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da concentração das fibras do tecido conjuntivo quando da associação de poliglactina 910 e silicone: estudo experimental em ratos

Neste estudo observamos a reação tecidual após implantação de próteses de silicone associadas à poliglactina 910. Telas de borracha de silicone com 1,5 x 1,5cm de diâmetro e 0,7mm de espessura, polifenestradas, foram implantadas no subcutâneo do dorso de ratos.Dois grupos foram observados, no primeiro apenas telas fenestradas eram implantadas, no segundo as fenestrações das telas eram preenchidas com fios de poliglactina 910. Os animais foram observados por 30, 60 e 90 dias quando eram sacrificados e as telas mais o tecido adjacente ressecados. Não se observou diferenças na quantidade de fibras colágenas entre os subgrupos de um mesmo grupo e ou quando comparados com os subgrupos do grupo em estudo. No grupo controle, onde se usou apenas as telas fenestradas de silicone houve uma diferença significante entre as fibras reticulares, em maior número nos grupos de 30 e 60 dias de observação, quando comparadas ao grupo de 90 dias. A poliglactina 910 associada ao silicone não alterou o número de fibras do tecido conjuntivo, contadas nas fenestrações das telas.