The biomedical applications of silicones are countless due to their outstanding properties. In dentistry, silicone for maxillofacial and plastic surgery has become indispensable, from both physiological and aesthetic points of view. In this mini-review, silicone materials for dentistry and facial prostheses are discussed, focusing on their properties and alterations when exposed for long periods to different environments. A significant number of studies reported in the literature have been conducted in vitro, mimicking some of the main degradative factors which have been identified as triggers for discoloration and deterioration of the mechanical properties. Among these, in artificial aging and accelerated natural aging studies, UV radiation is considered the most important. Other weathering factors, biological contamination, and disinfection agents may have dramatic effects as well. Several general properties of silicones are described at the beginning, with a focus on biocompatibility, cross-linking mechanisms, and applications in dentistry and maxillofacial prosthetics. We discuss the ongoing cross-linking and/or possible exudation after manufacturing, which also affects the stability of the prosthesis over time, and possibly the patient. Next, the main environmental factors that affect the prostheses in service are presented, including the role of cigarettes smoke, which has been discussed very little so far. A few aspects, such as biofilm formation, its negative effects, and proposed solutions to overcome this phenomenon regarding silicones, are also described. We conclude by proposing a set of topics for future research and development based on the gaps that have been identified in the literature. Although silicones are probably irreplaceable in maxillofacial prosthetics, improvements in terms of base materials, additives, surface treatments, and maintenance are possible and necessary for long-lasting and safer prostheses.

Objectives: Some small defects may remain in the impression after making a two-step putty-light body impression. The aim of this study was to evaluate and compare the dimensional accuracy of 2-step and relined 2-step (3-step) putty-light body impressions. Materials and Methods: In this in vitro study, 30 impressions were made with putty, light body, and extra-light body addition silicone materials using the 2-step and 3-step impression techniques (N=15). An epoxy resin master model was made duplicating a maxillary typodont with left first premolar and first molar teeth prepared with a shoulder finish line and truncated pyramidal-shaped indices in the mid-palate and third molar sites. In addition to creating a reference digital model by scanning the master model, 30 master casts were scanned to produce digital models. The anteroposterior (AP) and cross-sectional (CS) dimensional accuracy of the models were compared with the master model using linear measurements. Moreover, tooth size measurements were made and compared using the root mean square (RMS). Two-sample t-test was applied to analyze the data (α=0.05). Results: The mean AP and RMS differences between the two study groups were not significant (P>0.05). However, the CS difference between the two groups was significant (P<0.001), and the 3-step impression technique showed smaller discrepancies in comparison to the master model. Conclusion: There was no significant difference in accuracy of the two techniques for single-unit and multiple-unit preparations. The 3-step impression technique had a higher CS dimensional accuracy.

UNASSIGNED: Multiple techniques are available for closing skin defects, such as skin grafts, flaps and tissue expansion. The tissue extender MID SEW (MID, France) was developed to achieve dermatotraction or suture reinforcement. The aim of this study was to evaluate the effectiveness and safety of this innovative silicone extender for large surgical wounds.
UNASSIGNED: A single-centre retrospective and observational study on an unselected consecutive cohort of patients treated with a tissue extender was conducted. Indications, initial and final wound surfaces, and adverse events (AEs) were retrieved from electronic medical records. The main outcome measure was the time to complete wound closure.
UNASSIGNED: We identified 50 patients from July 2017 to December 2018. Patients underwent cutaneous tumour-wide excision (n=44), or pilonidal disease surgical treatment (n=6). The average initial wound area was 53.3±42.4cm2. Healing was complete, without secondary dehiscence, within the first seven days after device withdrawal for 41 patients (82%). At least one AE was experienced by eight patients (16%) during the study period: five inflammation; five wound dehiscence; two skin necrosis; and one pain.
UNASSIGNED: This case series suggests that the tissue extender may be effective and safe in its dermatotraction and suture reinforcement indications in the treatment of large wounds after wide excision of skin cancer or treatment of pilonidal disease.
UNASSIGNED: This work was supported in part by the Hospices Civils de Lyon, France and in part by the University Claude Bernard Lyon 1, France. OB co-owns the patent on the MID SEW system. The authors have no other conflicts of interest to declare.

Objective: To assess the efficacy of silicone earplugs in protecting workers exposed to noise in a typical manufacturing environment, and to provide training interventions for workers who do not achieve the anticipated noise reduction levels, as well as examining the spectral characteristics of earplug attenuation. Methods: From June to August 2022, a total of 294 noise-exposed workers in two manufacturing enterprises equipped with the same type of earplug were studied by cluster sampling method, by conducting questionnaire surveys, collecting data, fitting tests, and providing trainings, the current noise exposure levels of workers in the industry as well as the perception about the earplug were understood. Additionally, the attenuation before and after intervention in workplace were measured, the spectral characteristics of noise reduction were were described and compared. Results: The percentage of workers with Personal Attenuation Rating (PAR) of 0 is 32.7% (96/294), and the baseline pass rates are all below 60%. There were no significant differences in pass rates based on gender, age, noise exposure, education level, or cognition of earplug effectiveness. After adjusting the way that earplugs are worn or changing the type of earplugs, all workers were able to meet their noise reduction requirements. The median PAR improvement for both companies is above 10 dB. The noise attenuation of the earplug vary with frequency, with lower attenuation at 4 000 Hz and higher attenuation at 8 000 Hz, showing some deviation from the nominal values. Conclusion: The difference between the actual sound attenuation value of earplugs and the nominal value is related to the noise frequency. When using silicone earplugs, attention should be paid to the spectral composition of the noise in the workplace.
目的： 评估制造业企业噪声暴露工人佩戴某预制型硅胶耳塞的防护效果，对未达到预期降噪水平的工人进行培训干预，并了解耳塞衰减的频谱特征。 方法： 于2022年6至8月，选择两家配发同种耳塞的制造企业，采用整群抽样方法选择294名噪声暴露岗位工人作为研究对象，通过问卷调查、资料收集、声衰减测试及培训干预，对企业工人声暴露现状及对佩戴耳塞的主观认知、耳塞佩戴的实际衰减及干预后的衰减及硅胶耳塞降噪的频谱特征进行描述与组间比较。 结果： 基线个人声衰减值（personal attenuation rating，PAR）值为0的工人占32.7%（96/294），两企业PAR基线通过率均不足60%；不同性别、年龄、接噪工龄、受教育程度及工人对耳塞主观认知差异的PAR基线通过率差异均无统计学意义（P>0.05）。干预后两企业工人PAR提升值中位数均>10 dB；不同频率的PAR差异有统计学意义（P<0.05）；PAR与标称值在4 000 Hz处差距较大。 结论： 耳塞的实际声衰减值与标称值之间的差值与噪声频率有关，使用硅胶耳塞时需要关注场所噪声的频谱成份。.

BACKGROUND: This prospective clinical study evaluates the effect of a silicone stent tube (SST) on the success rate of endonasal-endoscopic dacryocystorhinostomy (EN-DCR) to treat primary acquired nasolacrimal duct obstruction.
METHODS: Patients were randomly assigned to receive EN-DCR with or without SST intubation over a period of 3 months. The surgery was performed using standardized techniques. Patients were assessed at three different timepoints: one day, 12 weeks and 24 weeks after the surgery. The results were compared in order to evaluate statistical differences. Surgical success was determined by means of positive irrigation procedures, as well as by the improvement of symptoms and a high level of patient satisfaction.
RESULTS: A total of 56 randomized cases completed 24 weeks of follow up. 1 Patient dropped out due to malignant genesis of the nasolacrimal duct obstruction. After 24 weeks of follow up no statistically significant differences in levels of epiphora (p > .10) or patency (p > .16) were revealed. Comparisons regarding changes in time did not show levels of significance (p > .28).
CONCLUSIONS: This study could not confirm a statistically significant benefit or disadvantage for SST Insertion in EN-DCR.

METHODS: A 64-year-old man presented with a 3-year history of right wrist pain and swelling 33 years after a silicone scaphoid arthroplasty for chronic scaphoid nonunion. Radiographs demonstrated a deformed scaphoid implant, carpal and distal radius cysts, and mild carpal collapse. He elected to undergo a wrist arthrodesis with a dorsal fusion plate after failing conservative management.
CONCLUSIONS: Although carpal bone silicone implant arthroplasties of the wrist have long been abandoned, our patient was pain free and fully functional for 3 decades. He was pleased to undergo serial examinations with radiographs for 30 years without any therapeutic intervention.

UNASSIGNED: Skin breakdown is common in the intensive care unit (ICU). This pilot evaluation aimed to determine whether a nurse-constructed urinary catheter securement device using a silicone adhesive could reduce the complications of blistering and other skin breakdowns in a high-risk ICU population with Foley catheters.
UNASSIGNED: A prospective, non-randomised performance improvement study using a convenience sample was carried out.
UNASSIGNED: The study sample consisted of 29 patients with urethral Foley catheters and any degree of thigh oedema in a surgical ICU at an academic quarternary medical center.
UNASSIGNED: Patients were fitted with a standard acrylic-adhesive catheter securement device on one thigh and a nurse-constructed device on the contralateral thigh. At the beginning of each 12-hour shift, the nurse moved the Foley catheter from one securement device to the other; the nurse recorded the assessment findings at the end of the shift.
UNASSIGNED: The average age of the 29 patients was 61±16 (range 20-87) years. Visible skin compromise occurred in 21% of the time with the standard acrylic securement device; an equal percentage of men and women developed skin breakdown. Oedema status was a significant factor related to skin breakdown. There was no visible damage to the skin associated with the nurse-constructed silicone-adhesive device.
UNASSIGNED: A silicone adhesive urinary catheter securement device causes less skin damage than one with acrylic adhesive. One-step application, pain-free and atraumatic removal, and reliable securement are essential considerations in product development.

BACKGROUND: Post-Covid Syndrome, Sick Building Syndrome, Silicone Breast Syndrome, Choric Fatigue Syndrome, Fibromyalgia -Autoimmunity to the Autonomic Nervous System.

Stimuli-responsive adhesives with on-demand adhesion capabilities are highly advantageous for facilitating wound healing. However, the triggering conditions of stimuli-responsive adhesives are cumbersome, even though some of them are detrimental to the adhesive and adjacent natural tissues. Herein, a novel stimuli-responsive adhesive called shear-stiffening adhesive (SSA) has been created by constructing a poly(diborosiloxane)-based silicone network for the first time, and SSA exhibits a rate-responsive adhesion behavior. Furthermore, we introduced bactericidal factors (PVP-I) into SSA and applied it as a wound dressing to promote the healing of infected wounds. Impressively, the wound dressing not only has excellent biocompatibility and long-term antibacterial properties but also performs well in accelerating wound healing. Therefore, this study provides a new strategy for the synthesis of intelligent adhesives with force rate response, which simplifies the triggering conditions by the force rate. Thus, SSA has great potential to be applied in wound management as an intelligent bioadhesive with on-demand adhesion performance.

Oil spills in the ocean and the release of contaminated wastewater from industries cause significant harm to the ecosystem and water sources. To tackle this environmental problem, oil-water mixture separation has been the subject of extensive research over the past few decades. Improving oil absorbents is crucial in removing organic contaminants from wastewater produced by industrial activities. To this end, there is an increasing need for materials that can efficiently and flexibly recover oils from contaminated ocean waters, industrial wastewater, and other sources. Silicones are often used for this purpose because of their exceptional mechanical and thermal durability, as well as their low toxicity. The materials produced from silicones, such as foam, sponge, or substrate, exhibit excellent oil-absorbing properties (maximum oil absorption range, 23.2-77 g/g) and outstanding compression cycles. This article review highlights the advancements in the manufacturing of silicone-based products that have been extensively researched for oil-water separation. Understanding the interdependencies that determine the structure, performance, and manufacturing strategy is essential to producing selective oil absorbents with more commercial potential in the future. Recycling of silicones has also become increasingly important as a goal for the circular economy.