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Purpose: The aim of this study was to evaluate the color stability of a facial silicone with different pigmentations submitted to disinfection and accelerated aging. Materials and Methods: Sixty replicas were fabricated with the silicone Silastic MDX 4-4210 and divided into three groups: no pigmentation, pigmentation with makeup powder, and pigmentation with ceramic powder. Half the replicas of each group were submitted to disinfection with Efferdent and the other with neutral soap for 60 days (n = 10). After this period, all replicas were inserted in a chamber for accelerated aging of nonmetallic specimens. The color measurements were carried out initially, after disinfection, and after accelerated aging (252, 504, 1008 hours). Color stability was evaluated through spectrophotometry. The values were submitted to ANOVA and the means to Tukey's test (p < 0.01). Results: The specimens disinfected with neutral soap exhibited higher ΔE values regardless of the type of pigmentation. The colorless replicas and the specimens pigmented with ceramic exhibited a statistically significant difference between the methods of disinfection in all periods. The specimens pigmented with makeup powder did not demonstrate a statistically significant difference. Conclusions: The ceramic pigment presented greater color stability regardless of disinfection and period. On the other hand, the makeup pigment exhibited the highest values of chromatic alteration.

Color stability of resin and silicone is an important factor for longevity of facial prostheses. The aim of this study was to evaluate the color stability of resins and silicone for facial prostheses. Three brands of acrylic resin and 1 of facial silicone were evaluated considering pigment incorporation for the colorless materials. Ten samples of each material were fabricated and submitted to measurements of chromatic alteration initially and after 252, 504, and 1008 hours of weathering through visual analysis and spectrophotometry. Data were evaluated by analysis of variance and Tukey test (P < 0.05). Results showed a statistically significant difference in color alteration among materials independent of aging. According to visual analysis, the color difference between pigmented and colorless Silastic MDX4-4210 and between pigmented and colorless Classico acrylic resin was statistically significant for the 3 weathering periods. Aging for 1008 hours represented a significant influence on color alteration of all resins. All materials presented chromatic alteration after accelerated artificial aging.

Purpose: The purpose of this study was to evaluate the color stability of two silicones for use in facial prostheses, under the influence of chemical disinfection and storage time. Materials and Methods: Twenty-eight specimens were obtained half made from Silastic MDX 4-4210 silicone and the other half from Silastic 732 RTV silicone. The specimens were divided into four groups: Silastic 732 RTV and MDX 4-4210 with disinfection three times a week with Efferdent and Sliastic 732 RTV and MDX 4-4210 disinfected with neutral soap. Color stability was analyzed by spectrophotometry, immediately and 2 months after making the specimens. After obtaining the results, ANOVA and Tukey test with 1% reliability were used for statistical analysis. Results: Statistical differences between mean color values were observed. Disinfection with Efferdent did not statistically influence the mean color values. Conclusion: The factors of storage time and disinfection statistically influenced color stability; disinfection acts as a bleaching agent in silicone materials.

Complete and partial loss of maxillary bone may jeopardize oral physiology and generate complications as oral-sinus-nasal communication. Palatal obturator prostheses are a treatment alternative for rehabilitation of these patients. The aim of this study was to assess stress distribution, through photoelasticity, on palatal obturator prostheses associated with different attachment systems (o'ring, bar clip, and o'ring/bar clip) of implants and submitted to relining. Two photoelastic models were fabricated according to an experimental maxillary model with oral-sinus-nasal communication. One model did not present implants, whereas the other included 2 implants with 13.0 mm in length in the left ridge. Four colorless maxillary obturator prostheses were fabricated and relined with soft silicone. One of these prostheses presented no attachment system, whereas the remaining prostheses included attachment systems adapted to the implants. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope during loading with 100 N at 10 mm/s. The results were based on observation during the experiment and photographic records of stress on the photoelastic model. The bar clip system exhibited the highest stress concentration followed by o'ring/bar clip and o'ring systems. The attachment systems presented different stress distribution with greater concentration surrounding the implants and homogenous stress distribution on the photoelastic model without implants. The highest concentration of fringes occurred, in ascending order, with o'ring, o'ring/bar clip, and bar clip systems.

The objectives of this study were, through a literature review, to point the differences between orbital implants and their advantages and disadvantages, to evaluate prosthesis motility after orbital implants are inserted, and to point the implant wrapping current risks. Sixty-seven articles were reviewed. Enucleation implants can be autoplastics or alloplastics and porous (including natural and synthetic hydroxyapatite [HA]) or nonporous (silicone). Hydroxyapatite is the most related in the literature, but it has disadvantages, too, that is, all orbital implants must be wrapped. Exposure of the porous orbital implant can be repaired using different materials, which include homologous tissue, as well as autogenous graft, xenograft, and synthetic material mesh. The most used materials are HA and porous polyethylene orbital implant. The HA implant is expensive and possibly subject corals to damage, different from porous polyethylene orbital implants. Porous implants show the best prosthesis motility and a minimum rate of implants extrusion. Implant wraps can facilitate smoother entry of the implant into the orbit and allow reattachment of extraocular muscles. They also serve as a barrier between the overlying soft tissue and the rough surface of the implant, protecting implants from exposure or erosion.

The use of photoelastic analysis contributes to the rehabilitation of patients with oral-sinus-nasal seque- lae, which in turn affect important functions such as chewing, swallowing, and speech. The prosthetic rehabilitation with implant-retained dentures is a suitable treatment option. The purpose of this study was to verify, by using a photoelastic analysis, the stress distribution in implant-retained palatal obturator dentures (relined or not) associated with different attachment systems (O-ring, bar-clip, and bar-clip associated with distally placed O-rings). Two photoelastic models were obtained from an experimental maxillary cast presenting an oral-nasal communication. One model had two 13-mm length implants placed on the left region. A total of eight colorless maxillary obturators were fabricated and subsequently four of them were relined with soft silicone soft, and three had attachment systems associated. The assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a 100-N load was applied at 10 mm∕s. The results showed that the denture relining influenced the distribution and amount of stress on the models. The O-ring group displayed the lowest stress levels, followed by bar-clip system associated with distally placed O-rings and bar-clip groups. © 2012 Society of Photo-Optical Instrumentation Engineers