Characterisation of Implant Supported Soft Tissue Prostheses Produced with 3D Colour Printing Technology

The numbers of patients needing facial prostheses has increased in the last few decades due to improving cancer survival rates. The many limitations of the handmade prostheses together with rapid expansion of prototyping in all directions, particularly in producing human anatomically accurate parts, have raised the question of how to employ this technology for rapid manufacturing of facial soft tissue prostheses. The idea started to grow and the project was implemented based on CAD/CAM principles – additive manufacturing technology, by employing layered fabrication of facial prostheses from starch powder and a water based binder and infiltrated with a silicone polymer (SPIS). The project aimed to produce a facial prosthesis by using 3D colour printing, which would match the patient’s skin shade and have the desirable mechanical properties, through a relatively low cost process that would be accessible to the global patient community. This was achieved by providing a simple system for data capture, design and reproducible method of manufacture with a clinically acceptable material. The prosthesis produced has several advantages and few limitations when compared to existing products/prostheses made from silicone polymer (SP). The mechanical properties and durability were not as good as those of the SP made prosthesis but they were acceptable, although the ideal properties have yet to be identified. Colour reproduction and colour matching were more than acceptable, although the colour of the SPIS parts was less stable than the SP colour under natural and accelerated weathering conditions. However, it is acknowledged that neither of the two methods used represent the natural life use on patients and the deficiencies demonstrated in terms of mechanical properties and colour instability were partially inherent in the methodology used, as the project was still at the developmental stage and it was not possible to apply real life tests on patients. Moreover, deficiencies in mechanical and optical properties were probably caused by the starch present, which was used as a scaffold for the SP. Furthermore, a suitable retention system utilising existing components was designed and added to the prosthesis. This enabled the prosthesis to be retained by implants with no need for the addition of adhesive. This would also help to prolong the durability and life span of the prosthesis. The capability of the printer to produce skin shades was determined and it was found that all the skin colours measured fall within the range of the 3D colour printer and thereby the printer was able to produce all the colours required. Biocompatibility was also acceptable, with a very low rate of toxicity. However, no material is 100% safe and each material has a certain range of toxicity at certain concentrations. At this stage of the project, it can be confirmed that facial prostheses were successfully manufactured by using 3D colour printing to match the patient’s skin shade, using biocompatible materials and having the desirable mechanical properties. Furthermore, the technology used enabled prostheses to be produced in a shorter time frame and at a lower cost than conventional SP prostheses. They are also very lightweight, easier to use and possibly more comfortable for the patients. Moreover, this technology has the capability of producing multiple prostheses at the time of manufacture at reduced extra cost, whilst the data can be saved and can be utilised/modified for producing further copies in the future without having to going through all the steps involved with handmade prostheses. Based on the mechanical properties and colour measurements the prostheses will have a finite service life and the recommendation is that these prostheses will need replacing every 6 to 12 months, depending on how the patient handles and maintains the prostheses and whether the prosthesis is being used as an interim or definitive prosthesis. This was largely comparable to existing prostheses but without the time and cost implications for replacement. However, it is acknowledged that further investigations and clinical case studies are required to investigate the “real life” effect on the prostheses and to get feedback from the patients in order to make appropriate improvements to the mechanical properties and the durability of the prosthesis

Primary Fallopian Tube Carcinoma Arising in the Setting of Chronic Pelvic Inflammatory Disease

Primary fallopian tube cancer (PFTC) is a rare gynaecological malignancy, clinically often mistaken for pelvic inflammatory disease or ovarian cancer. Three primary fallopian tube carcinomas, arising in a background of chronic pelvic inflammatory disease (PID), are presented. The possible association between chronic PID and PFTC is discussed and a hypothesies linking these cancers with chronic inflammation is proposed

Metastatic Prostate Cancer to the Urethra Masquerading as Urothelial Carcinoma

AbstractTumors of the urethra, whether primary or metastatic, are very rare. The true nature of urethral neoplasm is not always obvious clinically nor in routine histological sections. Immunostains should be performed on such lesions because of management implications. We present a case of multiple metastases to the urethra from a prostatic carcinoma, masquerading as multiple urothelial carcinomas. Pathologists and urologists should be aware of the possibility of metastasis from the prostate

Mammary Ductal Carcinoma In Situ: A Fresh Look at Architectural Patterns

Mammary ductal carcinoma in-situ (DCIS), a malignant appearing lesion on cytological and histological grounds, is in fact a non-obligate precancer. DCIS is difficult to manage and is sometimes treated more aggressively than invasive carcinoma. Although most DCIS classifications take into account the architectural growth pattern, when it comes to architecture, the literature is full of contradictory information. We examined 289 breast cancers and found DCIS in 265 of the cases. The majority of the DCIS cases were seen in the setting of invasive cancer and only 9% of the cases represented pure DCIS with no invasive cancer. The DCIS commonly displayed a mixed pattern with micropapillary, cribriform and solid components with the micropapillary type being the rarest, occurring seldom on its own. A continuum of growth with a micropapillary pattern evolving into a cribriform type could be seen in some of the cases. This may explain some of the conflicting information, in the literature, regarding the different architectural types of DCIS. The comedo-pattern of necrosis could be seen in all types of DCIS. We therefore conclude that the study of the determinants of growth pattern in DCIS would be the key to unravelling the diverse, often non-concordant evidence one encounters in the literature

MECHANICAL PROPERTIES OF 3D PRINTED FACIAL PROSTHESES COMPARED TO HANDMADE SILICONE POLYMER PROSTHESES

Purpose: To evaluate the mechanical properties of the 3D printed starch models infiltrated with maxillofacial silicone polymers used for fabrication of maxillofacial prostheses compared to the mechanical properties of pure silicone polymer models. Materials and methods: The test and control specimens were designed according to industry standards ASTM specifications using SolidWorks 2008 software for testing tensile strength tear strength, percentage elongation and hardness properties of starch infiltrated silicone polymer. Ten Dumbbell-shaped specimens and ten Trousershaped specimens with four hardness test specimens were printed by Zcorp 510 3D printer and infiltrated with Sil-25 maxillofacial silicone polymer. Whereas, control samples made from pure Sil-25 silicone polymers using a stainless steel mould and following a similar specification of test specimens. Lloyd LRX tensile instrument; load rating 100 N at a constant crosshead speed of 25 mm/min for testing tensile, tear strength and percentage elongation and Hardness Tester (England) was used to measure shore A durometer hardness. Results: Silicone polymer infiltrated starch (test) specimens demonstrated significantly lower tensile strength, tear strength and percentage elongation than the pure silicone polymer (control) samples (p<0.05). However, a significant increase (p<0.05) in the hardness of the printed specimens was recorded against the pure silicone samples. Conclusion: The 3D printed soft tissue prostheses – the final product showed significantly different mechanical properties compared to the handmade prostheses; they were significantly harder and reported lower mechanical properties

MECHANICAL PROPERTIES OF 3D PRINTED FACIAL PROSTHESES COMPARED TO HANDMADE SILICONE POLYMER PROSTHESES

Purpose: To evaluate the mechanical properties of the 3D printed starch models infiltrated with maxillofacial silicone polymers used for fabrication of maxillofacial prostheses compared to the mechanical properties of pure silicone polymer models. Materials and methods: The test and control specimens were designed according to industry standards ASTM specifications using SolidWorks 2008 software for testing tensile strength tear strength, percentage elongation and hardness properties of starch infiltrated silicone polymer. Ten Dumbbell-shaped specimens and ten Trousershaped specimens with four hardness test specimens were printed by Zcorp 510 3D printer and infiltrated with Sil-25 maxillofacial silicone polymer. Whereas, control samples made from pure Sil-25 silicone polymers using a stainless steel mould and following a similar specification of test specimens. Lloyd LRX tensile instrument; load rating 100 N at a constant crosshead speed of 25 mm/min for testing tensile, tear strength and percentage elongation and Hardness Tester (England) was used to measure shore A durometer hardness. Results: Silicone polymer infiltrated starch (test) specimens demonstrated significantly lower tensile strength, tear strength and percentage elongation than the pure silicone polymer (control) samples (p<0.05). However, a significant increase (p<0.05) in the hardness of the printed specimens was recorded against the pure silicone samples. Conclusion: The 3D printed soft tissue prostheses – the final product showed significantly different mechanical properties compared to the handmade prostheses; they were significantly harder and reported lower mechanical properties

Optimization of Maxillofacial Prosthesis

Today, both additive manufacturing (3D image technology and 3D printing) had been developed dramatically and involved virtually in all fields of medicine and surgery. It has been widely applied in surgical and prosthetic reconstruction of the craniofacial defects. The aim of this chapter is to characterize and assess the mechanical and optical properties of 3D colored printed soft tissue facial prostheses produced by Z-Corp-Z510 and infiltrated with Sil-25 maxillofacial silicone polymers. Mechanical properties assessed according to ASTM specifications for tensile strength, tear strength, hardness and percentage elongation. Furthermore depth of infiltration plus quality of infiltration was assessed. Scanning electron microscopy SEM was applied for this purpose to determine the characteristic of interaction and incorporation between the starch powder particles and the silicone polymers. Finally, method of color reproduction and evaluation for the printed prostheses are recommended