Special Thread Research Articles

Evaluating the properties of sewing thread for items for industrial and special applications in standardizing them

Using the index of the breaking load of one bearing element of the stitching seam for evaluating the performance reliability of industrial and special sewing thread is proposed. A method is proposed for determining the acceptable cyclically applied tensile loads that do not cause thread seams to break during use of the articles. The results of testing an assortment of industrial and special-application sewing thread allow selecting a sewing thread with consideration of the use of the articles.

Four-dimensional ultrasound visualising in a distraction model in pigs

The distraction of the maxilla is a standard surgical procedure. So far it is unknown, how the suture will react during the distraction and why not in all cases a sufficient expansion of the maxilla is possible. In an experimental animal study special conserved segments of the maxilla were distracted. In a first group 10 maxilla segments (age of the pig 90 days) and in a second group also 10 maxilla (age 180 days) were fixed in plastic. Using a special screw thread distraction, which was fixed in both parts of the maxilla, a horizontal distraction was possible. In the plastic blocks additionally 6 metal pins were inserted, to determine the horizontal distance. The distraction was simultaneously carried out in 0.25 mm steps to a distance of 2 mm. By four-dimensional (4D) ultrasound (LOGIQ® 9, real time 4D option R7x, GE Ultraschall, Germany) the maxilla could be shown and measured in a water bath after every step. The minimal resolution of this system was 0.3 mm. In a distraction of <0.5 mm sonographically a dispersion of the bone next to the suture could be found. In 90% a linear fracture next to the suture could be found, showing a one-sided as well as a both sided paramedian fracture. But also a fracture which was located in the lateral maxilla was seen. The distance measurement between the pins and in ultrasound showed that after a distraction of 0.25 mm no distraction of the bone and also of the pins could be found. The demonstrated sonographic control of maxilla distraction offers the possibility to visualise micro changes in distraction and shows fracture patterns.

APPLICATION OF A SPECIAL SEWING THREAD TO GATHERING

In order to produce gathering on the fabric, it is a normal method to tighten the thread sewed on fabric. In this paper a new method is presented for producing gathering on the fabric. A special thread (Acrylic95%, polyurethane5%) shrunk by treating with steam as a sewing thread to sew on the fabric. Then, the sewed fabric is treated by steam to produce gathering. The gathering ratio of the fabric is measured and the mechanical properties of the fabric are investigated.

Artificial dental root made of natural calcium carbonate (bioracine)

‘Bioracine’ is an artificial dental root made of natural calcium carbonate ( Pinctade maxima mother of pearl). This non-biodegradable material is very close to bone tissue in its physicochemical composition and presents remarkable hardness, resistance and elasticity. Bioracine is a buried dental implant with a special screw thread, presenting a large surface which shows pores of 2–3 μm. A histological study of the interface between the implant and human maxillary bone demonstrated an extraordinary cellular union between these two tissues. Furthermore, bioracine presents two new technical innovations: a periprosthetic epithelial attachment of connective tissue with an active shock absorbing system. Bioracine is an exceptional dental root substitute that matches the biological properties of natural bone.