Gypsum is derived from pure calcium sulfate dehydrate which is a common material that is commonly used in denture manufacturing process. This study aimed to know the difference on compressive strength and dimensional change of commercially type III gypsum compared to recycle type III gypsum to produce working cast. The type of research is laboratory experiment. A total of 40 samples for each test is divided into five groups which consists of commercial type III gypsum, pure recycled type III gypsum, pure recycled type III gypsum with 10%, 20%, 30% type III commercial gypsum. The difference on compressive strength and dimensional change between the groups was analyzed using one way ANOVA and is them tested with LSD test. The result showed that there was a significant difference (p<0,05) between compressive strength and dimensional change of commercial type III gypsum compared to pure recycled type III gypsum and pure recycled type III gypsum with 10%, 20% and 30% type III commercial gypsum. In conclusion, addition of 30% commercial gypsum in recycled gypsum the compressive strength was higher than other recycled gypsum types.
Aims: Metal-porcelain restoration is currently the most popular restoration that can be used for the anterior teeth. However the collar coping design on facial margin gingiva causes dark and shadowed zone in gingival, which is called "Umbrella Effect". This situation can overcomed by using collarless coping design. But this coping design has weaknesses such as decrease the fracture resistance of retoration. In some previous studies, the type of coping material can also affect fracture resistance. this study aimed to determined the effect of the coping material tipe and collarless margin design on the fracture resistance of restoration. Material and Methode: A total of 24 samples of metal-porcelain restorations from two material type and design were fabricated and cemented on 24 metal dies. The study was divided into four groups; Group A with Ni-Cr and Full Metal Collarless, Group B with Ni-Cr and Modified Metal Collarless, Group C with Co-Cr and Full Metal Collarless, and Group D with Co-Cr and Modified Metal Collarless. The measurement of fracture resistance was carried out using universal testing machine (Torsee UTM AMU-10, Tokyo, Japan) at a crosshead speed of 0.05 mm/minute. Loading point was applied at an angle of 45° until the porcelain layer fractured.
Introduction: The disfigurement associated with the loss of an eye can cause significant physical and psychological problems. Therefore, a good ocular prosthesis is needed to restore the patient's quality of life. One of the factors that determine the quality of an ocular prosthesis is accurately impression. In the case of enucleation where the eyes socket has a soft and movable tissue bad will result inaccurate impression. The difficulty of post enuclation impression in such case is the compression of the tissue eyes socket. This case report will discuss the modification in functional impression technique using a modified custom tray. Case: A 39-year-old male patient came to Dental Hospital Universitas Sumatera Utara with chief complaint an unaesthetic and loose left stock eye that had been used for 10 years. Clinical examination shows moderate depth eye socket with soft and movable tissue. Management: The functional impression technique was modified using a self-curing clear acrylic sclera without handle as a custom tray with 2 mm reduction on the intaglio surface and light body polyvinyl siloxane as impression material. Discussion: The aim of this modification is to avoid the tendency of the eye socket to compress during impression taking and to achieve a natural contour of the eyelid convexity because of the absence of the tray handle so the patient can close their eyes. Conclusion: This technique produces an ocular prosthesis that has a good retention with excellent aesthetic result.
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