Assessment of the color stability of two silicone elastomers for maxillofacial prostheses upon exposure to cold beverages.

PURPOSE: This study investigated the color stability of different commercially available silicone materials for facial prostheses upon exposure to everyday beverages. It was hypothesized that the beverages would not alter the color of the silicone under conditions simulating daily exposure. METHODS: Sixty specimens were fabricated using two materials - VST-50 and Silfy - and exposed to commercially available cold mineral water, tea, or coffee. Specimen color was evaluated on days 1 and 15. The color was measured with a spectrophotometer based on CIELab system and color differences were calculated as ΔE. Statistical analysis was performed using the Kruskal-Wallis test and Mann-Whitney U test. RESULTS: The mean ΔE values after 15 days of exposure to mineral water, cold green tea, and coffee were 1.016, 3.480, and 3.636 for VST-50 and 0.440, 0.798, and 1.425 for Silfy, respectively. Both materials showed significant differences in color, and VST-50 showed a greater color change than Silfy, especially for coffee. CONCLUSION: Pigmented silicone elastomers have low color stability, leading to an overall color change in silicone prostheses when exposed to pigmented beverages. Color changes in such prostheses can be mitigated by selecting materials with better color stability to extend their longevity.

Effect of Tea Tree Oil Addition to Denture Liners Against Candida albicans and Bond Strength to Acrylic Denture Bases.

PURPOSE: To evaluate the effect of adding tea tree oil to denture liners on Candida albicans and bond strength to the acrylic denture base. MATERIALS AND METHODS: Disc-shaped specimens were fabricated from silicone-based resilient liner (Tokuyama, Molloplast), acrylic-based hard liner (GC Reline), and acrylic-based soft liner (Visco-gel). Tea tree oil (TTO) was incorporated into the liners at varying concentrations (0% [control], 2%, 5%, 8%). C albicans were counted by viable colony count, and optical density (OD) was measured with a spectrophotometer. The tensile strength to heat polymerized acrylic denture base was measured in a universal testing machine. The compliance of the data to the distribution of normality was evaluated using the Shapiro Wilk test. Two-way ANOVA, Bonferroni correction, and paired sample t test were performed (α = .05). RESULTS: The addition of TTO into liners provided a significant decrease in the OD values (P < .001). The control groups of the liners presented the highest colony counts, whereas increasing TTO decreased the results (P < .01). According to tensile bond strength test, 8% TTO addition resulted in a significant decrease for Tokuyama (P < .01) and Molloplast liners (P < .05), while 2% TTO resulted in significance for GC Reline (P < .001). CONCLUSIONS: Denture liners containing increasing percentages of TTO presented lower amounts of C albicans colonies and decreased bond strength to the denture bases. When using TTO for its antifungal properties, the amount added should be carefully selected because the tensile bond strength may be affected.

An In Vitro Comparative Evaluation of Conventional and Novel Thymus vulgaris Derived Herbal Disinfectant Solutions against Pathogenic Biofilm on Maxillofacial Silicones and Its Impact on Color Stability.

AIM: This study aims to assess the antimicrobial efficacy and impact on color stability of Thymus (T.) vulgaris solution compared to conventional disinfectants on maxillofacial silicones. MATERIALS AND METHODS: Various solutions were evaluated, including T. vulgaris solutions at 5 and 10%, saline (control), chlorhexidine (4%), and soap water. The substrates were MDX4-4210 silicone elastomers, and the microorganisms tested were Candida (C.) albicans and Staphylococcus (S.) aureus. The viability of microorganisms was determined through an 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) reduction assay, and color stability was measured using a spectrophotometer with X-Rite Europe software. Statistical analysis was performed using the Kruskal-Wallis test, Mann-Whitney U post hoc test, and Wilcoxon Signed Rank test. RESULTS: Soap water demonstrated superior disinfectant action against both microorganisms, while T. vulgaris solutions at 5 and 10% exhibited comparable antimicrobial efficacy. Chlorhexidine and 10% T. vulgaris solution showed minimal color changes in the silicone material. In contrast, soap water and the 5% T. vulgaris solution resulted in clinically unacceptable color alterations. CONCLUSION: This study underscores the potential of T. vulgaris as an herbal disinfectant for combating microbial biofilms on maxillofacial silicones, particularly at concentrations of 5 and 10%. The importance of maintaining color stability is emphasized, with Chlorhexidine and the 10% T. vulgaris solution demonstrating effective preservation of esthetics. These findings suggest the viability of considering T. vulgaris as an alternative disinfectant in clinical settings for maxillofacial silicone prostheses. CLINICAL SIGNIFICANCE: Maxillofacial silicones are vital in restoring aesthetic features for individuals with facial trauma, congenital deformities, or post-surgical interventions. Yet, biofilm-related infections jeopardize their durability and visual integrity. Clinically, T. vulgaris signifies a potential advance in prosthodontic care, offering valuable insights for improving antimicrobial performance and aesthetic durability in maxillofacial prostheses. How to cite this article: Peter M, Kanathila H, Bembalagi M, et al. An In Vitro Comparative Evaluation of Conventional and Novel Thymus vulgaris Derived Herbal Disinfectant Solutions against Pathogenic Biofilm on Maxillofacial Silicones and Its Impact on Color Stability. J Contemp Dent Pract 2023;24(12):967-973.

Emissions of Fungal Volatile Organic Compounds in Residential Environments and Temporal Emission Patterns: Implications for Sampling Methods.

Currently, little is known about the occurrences of fungi-derived microbial volatile organic compounds (mVOCs) in various indoor materials and their detection in residential environments, despite mVOCs being linked to several acute health effects. We identified various mVOCs emitted from fungi grown on PVC wallpaper, silicone rubber, and malt extract agar. We also investigated mVOCs temporal emission and whether fungi-derived VOCs concentration can be used to estimate fungal concentration in the air using active and passive air sampling methods. Among the three fungal growth media included in this study, silicone rubber produced the most variety of mVOCs: 106 compounds (from Aspergillus niger), 35 compounds (from Alternaria alternata), and 85 compounds (from Penicillium chrysogenum). We also found the emission patterns of eight chemical classes (i.e., aromatics, ethers, aliphatics, alcohols, ketones, aldehydes, chlorides, and nitrides) from the three different fungi. From the results of our field experiments in 11 residential environments, passive air samplers led to higher correlations coefficients (0.08 to 0.86) between mVOCs' air concentrations and airborne fungal concentrations, compared with active air samplers, which showed negative correlation coefficients (-0.99 to -0.02) for most compounds. This study elucidated the occurrence and temporal emission patterns of fungal VOCs in residential environments.

Intraocular Lenses: Overview of Designs, Materials, and Pathophysiologic Features.

This article provides an overview of intraocular lenses (IOLs) currently used in cataract surgery. Aspects presented include design features related to IOL construction and sites of fixation; optic, filter, and haptic materials; as well as pathophysiologic features of uveal biocompatibility, capsular biocompatibility, and postoperative IOL opacification. This overview also includes supplementary (add-on; piggyback) lenses implanted in eyes that are already pseudophakic and considerations on IOLs used in the pediatric population. Different IOLs are made available to surgeons each year, including lenses with increasingly complex design characteristics owing to advancements in manufacturing and surgical techniques.

Soft Defect-Tolerant Material Inspired by American Lobsters.

The joint membrane of the American lobster shows an excellent combination of high strength, toughness, and defect tolerance due to the periodic helicoidal stacking of the fiber layers that are connected by a weak continuous matrix. Inspired by the joint membrane of American lobsters, we simply use nonwoven fabrics and silicon rubber to fabricate a multilayer soft composite with the helicoidal stacking and controllable matrix. The influences of stacking structure, matrix strength, fabrics strength, and notch size on the fracture behavior of the soft composite during the tensile process are systematically analyzed by both experimental tests and finite element analysis (FEA). We find that similar to the joint membrane, the soft composite demonstrates a gradual failure process and a linear relationship between tensile strength/toughness and notch size. Such phenomena demonstrate the strong defect-tolerant ability, thereby imparting the soft composite with both high strength and toughness. The defect-tolerant ability is closely related to the helicoidal stacking and weak matrix between the fabrics layers, which induce crack deflection and inhibit the propagation of cracks across the sample.

Antifungal and biofilm inhibitory effect of Cymbopogon citratus (lemongrass) essential oil on biofilm forming by Candida tropicalis isolates; an in vitro study.

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon citratus (lemongrass) essential oil has been widely used as a traditional medicine and is well known for antimicrobial properties. Therefore, it might be a potent anti-infective and biofilm inhibitive against Candida tropicalis infections. Until now, no ideal coating or cleaning method based on an essential oil has been described to prevent biofilm formation of Candida strains on silicone rubber maxillofacial prostheses, voice prostheses and medical devices susceptible to C. tropicalis infections. AIM OF THE STUDY: To investigate the antifungal and biofilm inhibitory effects of Cymbopogon citratus oil. Clinical isolates of C. tropicalis biofilms on different biomaterials were used to study the inhibitory effect. MATERIALS AND METHODS: The efficacy of Cymbopogon citratus, Cuminum cyminum, Citrus limon and Cinnamomum verum essential oils were compared on biofilm formation of three C. tropicalis isolates on 24 well polystyrene plates. C. citratus oil coated silicone rubber surfaces were prepared using hypromellose ointment as a vehicle. The antifungal tests to determine minimum inhibitory and minimum fungicidal concentrations were assessed by a microbroth dilution method and biofilm formation was determined by a crystal violet binding assay. RESULTS: C. tropicalis strains formed more biofilm on hydrophobic materials than on hydrophilic glass. C. citratus oil showed a high antifungal effect against all C. tropicalis strains. For comparison, C. limon oil and C. cyminum oil showed minor to no killing effect against the C. tropicalis strains. C. citratus oil had the lowest minimal inhibitory concentration of all essential oils tested and inhibited biofilm formation of all C. tropicalis strains. C. citratus oil coating on silicone rubber resulted in a 45-76% reduction in biofilm formation of all C. tropicalis strains. CONCLUSION: Cymbopogon citratus oil has good potential to be used as an antifungal and antibiofilm agent on silicone rubber prostheses and medical devices on which C. tropicalis biofilms pose a serious risk for skin infections and may cause a shorter lifespan of the prosthesis.

Optical parameters and hardness of two maxillofacial elastomers after immersion in different solutions of Brazilian green propolis extract.

STATEMENT OF PROBLEM: Maxillofacial elastomers undergo physical and mechanical degradation with disinfecting solutions. Solutions of Brazilian green propolis extract may be suitable alternatives for infection control of maxillofacial prostheses. However, their effects on the properties of the material are unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effect of disinfection with solutions of Brazilian green propolis extract on the transmittance, translucency parameter, contrast ratio, and hardness of 2 maxillofacial elastomers (MDX4-4210 and MED-4014). MATERIAL AND METHODS: Fifty disk-shaped specimens (3×10 mm) of each elastomer were randomly and equally divided into 4 groups of disinfectant agents and 1 control group: 3 separate groups of 11% green propolis extracts including aqueous (PAQ), glycolic (PGL), and alcoholic (PAL), a 2% chlorhexidine gluconate (CHX) group, and the control group of distilled water. Specimens were subjected to disinfection by immersion 3 times a week for 60 days. Color differences (ΔE values) were calculated with CIELab and CIEDE2000 formulas. Optical parameters and Shore A hardness were determined at 2 time points: at baseline and after the period of specimen disinfection. Data were analyzed by parametric and nonparametric analysis of variance and by multiple-comparison tests (α=.05). RESULTS: The ΔE values of specimens immersed in 11% PAL were not clinically acceptable for either elastomer. Regarding translucency parameter and contrast ratio, the immersion in 11% PAL and 11% PGL resulted in greater opacity and lower translucency of the material. Mean Shore A hardness values were not statistically significantly different at baseline or after 60 days of immersion in the solutions. CONCLUSIONS: The solution of Brazilian green propolis extract tested showed changes in optical parameters. Elastomers immersed in 11% alcoholic green propolis extract showed clinically unacceptable color and translucency changes. All hardness values of the tested elastomers were clinically acceptable after immersion in all tested disinfectant groups.

Clinical Results of Anti-adhesion Adjuvants after Endonasal Dacryocystorhinostomy.

PURPOSE: Various absorbable anti-adhesion agents have been used to prevent postoperative synechia formation after endonasal surgery. The purpose of this study was to evaluate the anti-adhesion effects of HyFence and Mediclore after endonasal dacryocystorhinostomy (DCR) compared to a mixed solution of hyaluronic acid and sodium carboxymethylcellulose (Guardix-Sol). METHODS: In this retrospective study, endonasal DCR and silicone tube intubation were performed on 198 eyes of 151 patients. Three different anti-adhesion adjuvants were applied to the osteotomy site in the nasal cavity after standard endonasal DCR procedures. The subjects were classified into three respective groups: group A (71 eyes, Guardix-Sol 1.5 g), group B (89 eyes, HyFence 1.5 mL), and group C (38 eyes, Mediclore 1 cc). The three groups were evaluated by asking patients about subjective symptoms and by performing lacrimal irrigation tests and endoscopic examinations. RESULTS: There were no statistically significant differences in age, sex, timing of tube removal, or follow-up period among the three groups. There were no statistically significant differences in success rates among the three groups (p = 0.990, 91.5% [65 / 71], 92.1% [82 / 89], and 92.1% [35 / 38], respectively). CONCLUSIONS: HyFence and Mediclore are safe and effective adjunctive modalities following endonasal DCR compared to Guardix-Sol. Therefore, these agents can be considered good alternatives to Guardix-Sol to increase the success rate of endonasal DCR in treating patients with poor prognosis.

Genomic identification of microbial species adhering to maxillofacial prostheses and susceptibility to different hygiene protocols.

This study investigated the microbial colonization of maxillofacial prostheses and support tissues using the Checkerboard DNA-DNA hybridization method, and the efficacy of 0.12% chlorhexidine gluconate, 10% Ricinus communis solutions, or brushing, on colony forming unit (CFU) reduction in monospecies biofilms (Candida glabrata, Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa) formed on two silicones (MDX 4-4210 and Bio-Skin). Biofilm was harvested from 43 maxillofacial prosthesis wearers for detection of 38 species of microorganisms. The CFU counts of the six above mentioned species were recorded after using the hygiene protocols. All 38 investigated species were identified in prostheses and tissues, with a higher prevalence in the prostheses. 0.12% chlorhexidine gluconate immersion showed the greatest antimicrobial effectiveness, followed by mechanical brushing protocols. MDX 4-4210 silicone produced lower CFU counts than Bio-Skin.

[ASIA syndrome: breast implant and Still's disease]. / Síndrome ASIA: Prótesis mamarias y enfermedad de Still.

Connective tissue diseases associated with silicone breast implants have been widely discussed. In the last decade, siliconosis has been included in the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) next to Gulf War syndrome, macrophage myofascitis and postvaccination phenomena. The ASIA syndrome may appear as lupus, rheumatoid arthritis, or more rarely, as adult Still's disease. We discuss the case of a patient with prolonged fever and clinical criteria for ASIA and Still's disease. The prostheses were resected and pathology showed absence of breast implant associated anaplastic lymphoma ALK (-). Physicians should be alert to these new entities linked to silicone breast implants.

Síndrome ASIA: prótesis mamarias y enfermedad de Still / ASIA syndrome: breast implant and Still's disease

Las enfermedades del tejido conectivo vinculadas a implantes mamarios de siliconas han sido tema de discusión. En la última década, la siliconosis ha sido incluida dentro del síndrome autoinmune/inflamatorio inducido por adyuvante (ASIA) junto al síndrome de la guerra del Golfo, síndrome de miofascitis macrofágica y fenómenos post vacunales. El ASIA puede manifestarse como lupus, artritis reumatoidea, o más raramente como enfermedad de Still del adulto. Presentamos el caso de una paciente con fiebre prolongada y criterios clínicos compatibles con ASIA y enfermedad de Still. Se resecaron las prótesis y la anatomía patológica descartó linfoma anaplásico ALK (-) vinculado a prótesis. Los médicos debemos estar alertas ante la aparición de estas nuevas entidades asociadas a los implantes mamarios de siliconas.

Connective tissue diseases associated with silicone breast implants have been widely discussed. In the last decade, siliconosis has been included in the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) next to Gulf War syndrome, macrophage myofascitis and postvaccination phenomena. The ASIA syndrome may appear as lupus, rheumatoid arthritis, or more rarely, as adult Still's disease. We discuss the case of a patient with prolonged fever and clinical criteria for ASIA and Still's disease. The prostheses were resected and pathology showed absence of breast implant associated anaplastic lymphoma ALK (-). Physicians should be alert to these new entities linked to silicone breast implants.

Transport features of nano-hydroxylapatite (n-HA) embedded silicone rubber (SR) systems: influence of SR/n-HA interaction, degree of reinforcement and morphology.

We report the transport characteristics of silicone rubber/nano-hydroxylapatite (SR/n-HA) systems at room temperature with reference to the effects of n-HA loading, morphology and penetrant nature, using toluene, xylene, ethyl acetate and butyl acetate in the liquid phase and methanol, ethanol, 1-propanol, 2-propanol and butanol in the vapour phase as probe molecules. The interaction between the n-HA particles and SR matrix has been confirmed by FTIR analysis. As the n-HA content in the SR matrix increased, the penetrant uptake has been found to decrease. The observations have been correlated with the density and void content of the systems. Scanning electron microscopy images have been found to be complementary to the observed transport features. The reinforcement effect of n-HA particles on the SR matrix has been verified by Kraus equation. Molecular mass between the cross links has been observed to decrease with an increase in n-HA loading. The results have been compared with affine, phantom network, parallel, series and Maxwell models. The transport data have been complemented by observations on biological fluid uptake with urea, d-glucose, KI, saline water, phosphate buffer and artificial urine as the media.

[Preparation and in vitro release evaluation of slow releasing intrauterine silicone rubber bar made of Panax notoginseng and Rubia cordifolia].

To prepare the intrauterine slow release silicone rubber bar made of Panax notoginseng and Rubia cordifolia, and finish its preliminary evaluation of in vitro releasing properties. The open mill method was used for plasticating of silicone rubber. The process parameters of the silicone rubber and drugs mixing were optimized by orthogonal test. The parameters of silicone rubber vulcanization was optimized by single factor test. The preliminary evaluation of in vitro release performance of the silicone rubber bar was conducted with ginsenoside Rg1, ginsenoside Rb1, notoginsenoside R1, purpurin and rubimaillin as the indexes. The results showed that optimum technologic parameters for silicone rubber and drugs mixing：the roller spacing 2 mm; speed ratio 1∶1.2; front roller temperature 55-60 ℃; rear roll temperature 50-55 ℃; and mixing time 20 min. The optimum parameters for silicone rubber vulcanization：temperature 90 ℃, and time 60 min. The studies on release process in vitro revealed that the release process of silicone rubber bar was in line with the Higuchi equations. After 90 days, the cumulative release of ginsenoside Rg1, ginsenoside Rb1 and notoginsenoside R1 was 46.7%, and the cumulative release of purpurin and rubimaillin was 51.9%. The preparation method can be applied to the preparation of silicone rubber bar, with slow release characteristics.

[Breast implant-associated anaplastic large-cell lymphoma: A case report and a review of literature]. / Assotsiirovannaia s implantatom anaplasticheskaia krupnokletochnaia limfoma molochnoi zhelezy: opisanie klinicheskogo sluchaia i obzor literatury.

Breast implant-associated anaplastic large-cell lymphoma will be identified as a separate nosological entity in the 2017 adapted WHO classification due to differences in its clinical presentations, pathogenesis, and prognosis with those of nodal and cutaneous anaplastic large-cell lymphomas. The paper gives a review of the literature and describes the authors' own clinical case of common breast implant-associated anaplastic large-cell lymphoma involving breast tissue, axillary lymph nodes, anterior chest muscles, and bone marrow. The treatment policy chosen by the authors could achieve complete remission.

Vitamin D deficiency as a risk factor for the development of autoantibodies in patients with ASIA and silicone breast implants: a cohort study and review of the literature.

The development of autoimmunity and/or autoimmune diseases is multifactorial. Vitamin D is one of the factors that might play a role. We postulated that both the presence of adjuvants and insufficient levels of vitamin D may result in the development of autoimmunity in patients with autoimmune/inflammatory syndrome induced by adjuvants (ASIA) in relation to silicone implant incompatibility. We measured vitamin D levels in 135 patients with ASIA in relation to silicone implant incompatibility and related findings to the presence of autoantibodies that are commonly used to diagnose systemic autoimmune diseases. Furthermore, we systematically reviewed the literature regarding vitamin D deficiency as a risk factor for the development of autoantibodies. Vitamin D measurements were available for analysis in 131 of 135 patients with ASIA in relation to SIIS. Twenty-three patients (18%) tested positive for autoantibodies, from which 18 patients (78%) had either a vitamin D deficiency or insufficiency (median vitamin D level 60.5 mmol/L), whereas five patients (22%) had sufficient vitamin D levels. The risk to develop autoantibodies was significantly increased in vitamin D deficient and/or insufficient patients [RR 3.14; 95% CI, 1.24-7.95; p = 0.009]. Reviewed literature suggested an association between vitamin D levels and the presence and/or titer levels of autoantibodies in different autoimmune diseases. From our current study and from our review of the literature, we conclude that vitamin D deficiency is related to the presence of autoantibodies. Whether vitamin D supplementation results in a decrease of autoimmunity needs to be studied prospectively.

Effects of Taxol on Regeneration in a Rat Sciatic Nerve Transection Model.

Recent studies describe taxol as a candidate treatment for promoting central nerve regeneration. However, taxol has serious side effects including peripheral neurotoxicity, and little information is known about the effect of taxol on peripheral nerve regeneration. We investigated the effects of taxol on regeneration in a rat sciatic nerve transection model. Rats were divided into four groups (n = 10): normal saline (i.p.) as the control, Cremophor EL vehicle, and 2 or 6 mg/kg of taxol in the Cremophor EL solution (four times in day-2, 4, 6, and 8), respectively. We evaluated neuronal electrophysiology, animal behaviour, neuronal connectivity, macrophage infiltration, location and expression levels of calcitonin gene-related peptide (CGRP), and expression levels of both nerve growth factors and immunoregulatory factors. In the high-dose taxol group (6 mg/kg), neuronal electrophysiological function was significantly impaired. Licking latencies were significantly changed while motor coordination was unaffected. Neuronal connectivity, macrophage density, and expression levels of CGRP was dramatically reduced. Expression levels of nerve growth factors and immunoregulatory factors was also reduced, while it was increased in the low-dose taxol group (2 mg/kg). These results indicate that taxol can modulate local inflammatory conditions, impair nerve regeneration, and impede recovery of a severe peripheral nerve injury.

An in-situ assessment of low-density polyethylene and silicone rubber passive samplers using methods with and without performance reference compounds in the context of investigation of polychlorinated biphenyl sources in rivers.

This study firstly aims to assess the field performances of low density polyethylene (LDPE) and silicone rubber (SR) samplers for the monitoring of polychlorinated biphenyls (PCBs) in water regarding the uptake, the sampling rate (RS) estimated by using performance reference compounds (PRCs) and the time-weighted average (TWA) concentrations. The second aim is to evaluate the efficiency of these samplers to investigate PCB sources (localization and imputation steps) using methods with and without PRCs to correct for the impact of water velocity on the uptake. Samplers spiked with PRCs were deployed in the outfalls of two PCB sources and at 8 river sites situated upstream and downstream of the outfalls. After 6weeks, the uptake of PCBs in the linear phase was equivalent in LDPE and SR but 5 times lower in LDPE for PCBs approaching equilibrium. PRC-based RS and water velocity (0.08 to 1.21ms-1) were well correlated in river (LDPE: R2=0.91, SR: R2=0.96) but not in outfalls (higher turbulences and potential release of PRCs to air). TWA concentrations obtained with SR were slightly higher than those obtained with LDPE (factor 1.4 to 2.6 in river) likely because of uncertainty in sampler-water partition coefficient values. Concentrations obtained through filtration and extraction of water samples (203L) were 1.6 and 5.1 times higher than TWA concentrations obtained with SR and LDPE samplers, respectively. PCB sources could efficiently be localized when PRCs were used (increases of PCB loads in river) but the impact of high differences of water velocity was overcorrected (leading sometimes to false positives and negatives). Increases of PCB loads in the river could not be entirely imputed to the investigated sources (underestimation of PCBs contributing to the load increases). A method without PRCs (relationship between uptake and water velocity) appeared to be a good complementary method for LDPE.

[Correction of congenital malformations by custom-made silicone implants: Contribution of computer-aided design. Experience of 611 cases]. / Chirurgie des malformations congénitales par implants sur mesure en silicone. Apport de la conception assistée par ordinateur (CAO). À propos d'une expérience de 611 cas opérés.

INTRODUCTION: Modern techniques of computer-aided design and tridimensional prototyping for manufacturing silicone elastomer custom implants are growing. They have widely modified the surgical indications in our unit. MATERIALS AND METHODS: By presenting their experience of 611 cases managed between 1993 and 2016, the authors describe the method of conception from CT-scans, the virtual image of the body and the manufacture of the custom-made implant perfectly adapted to the anatomy of each one. The operative techniques are described for the three main indications: the funnel chest or pectus excavatum (474 cases) according to a modified CHIN classification is corrected simply and very satisfactorily. This approach may render thoracic surgery techniques obsolete. Indeed, these operations remain risky and of doubtful functional utility; Poland syndrome (116 cases), where the use of a custom-made implant for compensation of muscle volume is frequently used, but can be improved by a transfer of adipose tissue or a classic breast implant; the leg atrophies (21 cases) receive custom elastomer implants introduced in a sub-fascial plane. RESULTS: The results are excellent for pectus excavatum but more difficult to optimize for the other two indications, requiring sometimes complementary techniques. Complications are rare and often benign, implants endure for life. Quality of life, psychological comfort and self-esteem have been improved with low morbidity and without having undergone a painful surgical experience. CONCLUSION: Reconstructive procedures of congenital malformations by custom-made silicone implants open a new field of activity for our surgical specialty with vast opportunities.

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.