İki farklı Co-Cr HBP alaşımının mekanik özelliklerinin karşılaştırılması

Purpose: The purpose of this study was to compare the mechanical properties of two different removable partial denture alloys that are commonly used in Çukurova University Faculty of Dentistry. Material and Methods: Using two different Co-Cr alloys; Magnum H60 (MESA, Travagliato, Italy) and Biosil F (Degussa Dental, GmbH, Hanau, Germany) ten tensile test specimens were prepared for each group according to the ADA specification number 14. Specimens were loaded to crack. Ultimate tensile strength and percent elongation of two groups were compared using Mann Whitney U test (α=0.05). Crack surfaces were investigated using a stereomicroskop. Results: A statistically significant difference was found between ultimate tensile strength of Magnum H60 (828 ± 17.3 MPa) and Biosil F (782 ± 51.6) (α =0.01). Percent elongation of Magnum H60 and Biosil F were found as 6.77 ± 1.62 and 6.32 ± 2.38, respectively. No significant difference was found among the two groups when the percent elongation was compared (α =0.496). Stereomicroscope images that are taken from the crack surfaces of both groups show similarities. Porotic structures and cracks that formed during solidification of the alloys can be seen on crack surfaces. Conclusion: Both of the Co-Cr removable partial denture alloys tested in the current study seem capable of serving in the mouth for a long time. ÖZET Amaç: Bu çalışmanın amacı Çukurova Üniversitesi Diş Hekimliği Fakültesi’nde sıklıkla kullanılmakta olan iki farklı hareketli bölümlü protez alaşımının mekanik özelliklerini karşılaştırmaktır. Gereç ve Yöntem: Magnum H60 (MESA, Travagliato, İtalya) ve Biosil F (Degussa Dental, GmbH, Hanau, Almanya) olmak üzere iki farklı Co-Cr alaşımı kullanılarak her grup için 10 örnek olmak üzere ADA’nın 14 nolu şartnamesine göre çekme testi örnekleri hazırlanmıştır. Örnekler kırılana kadar devam ettirilen çekme testinde iki grubun maksimum çekme dayanıklılığı ve uzama yüzdesi değerleri Mann Whitney U testi kullanılarak karşılaştırılmıştır (α=0.05). Kırılma yüzeyleri stereomikroskop kullanılarak incelenmiştir. Bulgular: Magnum H60 grubunun maksimum çekme dayanıklılığının (828 ± 17.3 MPa) Biosil F’nin dayanıklılığından (782 ± 51.6) istatistiksel açıdan anlamlı ölçüde yüksek olduğu bulunmuştur (α =0.01). Magnum H60 ve Biosil F gruplarının uzama yüzdeleri sırası ile 6.77 ± 1.62 ve 6.32 ± 2.38 olarak bulunmuştur. İki grubun uzama yüzdeleri arasında anlamlı bir farklılık bulunamamıştır (α =0.496). Kırılma yüzeylerinden alınan stereomikroskop görüntüleri benzerlik göstermektedir. Her iki gruba ait örneklerin kırılma yüzeyinde alaşımın sertleşmesi sırasında oluşmuş porotik yapılar ve çatlaklar izlenmektedir. Sonuç: Bu çalışmada test edilen Co-Cr alaşımlarının her ikisi de mekanik özellikleri açısından hareketli bölümlü protezlerin ağızda uzun süre kullanımı için uygundur. Anahtar Kelimeler: Hareketli bölümlü protezler, Co-Cr alaşımları, maksimum çekme dayanımı, uzama yüzdes

Geçmişten bugüne yüz protez materyalleri

This review described the evaluation facial prosthetics and explained the facial prosthetic materials. Nowadays, this increased success is related to the evaluation of the materials.   ÖZET Bu çalışmada yüz protezlerinin tarihsel gelişimine kısaca değinilmiş ve geçmişten günümüze kadar kullanılan yüz protez materyalleri açıklanmıştır. Bugün ulaşılan başarı, bu materyallerdeki gelişime bağlıdır. Anahtar Kelimeler: Yüz protez materyalleri, silikon elastomer, poliüretan

Metal-free restorations: esthetic considerations, treatment planning, preparation, manufacturing, luting, and followup

sem informação201

Geçmişten bugüne yüz protez materyalleri

<p>This review described the evaluation facial prosthetics and explained the facial prosthetic materials. Nowadays, this increased success is related to the evaluation of the materials.</p> <p> </p> <p><strong>ÖZET</strong></p> <p>Bu çalışmada yüz protezlerinin tarihsel gelişimine kısaca değinilmiş ve geçmişten günümüze kadar kullanılan yüz protez materyalleri açıklanmıştır. Bugün ulaşılan başarı, bu materyallerdeki gelişime bağlıdır.</p> <p><strong>Anahtar Kelimeler:</strong> Yüz protez materyalleri, silikon elastomer, poliüretan,</p&gt

İki farklı Co-Cr HBP alaşımının mekanik özelliklerinin karşılaştırılması

<p><strong>Purpose:</strong> The purpose of this study was to compare the mechanical properties of two different removable partial denture alloys that are commonly used in Çukurova University Faculty of Dentistry.</p> <p><strong>Material and Methods:</strong> Using two different Co-Cr alloys; Magnum H60 (MESA, Travagliato, Italy) and Biosil F (Degussa Dental, GmbH, Hanau, Germany) ten tensile test specimens were prepared for each group according to the ADA specification number 14. Specimens were loaded to crack. Ultimate tensile strength and percent elongation of two groups were compared using Mann Whitney U test (α=0.05). Crack surfaces were investigated using a stereomicroskop.</p> <p><strong>Results:</strong> A statistically significant difference was found between ultimate tensile strength of Magnum H60 (828 ± 17.3 MPa) and Biosil F (782 ± 51.6) (α =0.01). Percent elongation of Magnum H60 and Biosil F were found as 6.77 ± 1.62 and 6.32 ± 2.38, respectively. No significant difference was found among the two groups when the percent elongation was compared (α =0.496). Stereomicroscope images that are taken from the crack surfaces of both groups show similarities. Porotic structures and cracks that formed during solidification of the alloys can be seen on crack surfaces.</p> <p><strong>Conclusion:</strong> Both of the Co-Cr removable partial denture alloys tested in the current study seem capable of serving in the mouth for a long time.</p> <p><strong> </strong></p> <p><strong>ÖZET</strong></p> <p><strong>Amaç:</strong> Bu çalışmanın amacı Çukurova Üniversitesi Diş Hekimliği Fakültesi’nde sıklıkla kullanılmakta olan iki farklı hareketli bölümlü protez alaşımının mekanik özelliklerini karşılaştırmaktır.</p> <p><strong>Gereç ve Yöntem:</strong> Magnum H60 (MESA, Travagliato, İtalya) ve Biosil F (Degussa Dental, GmbH, Hanau, Almanya) olmak üzere iki farklı Co-Cr alaşımı kullanılarak her grup için 10 örnek olmak üzere ADA’nın 14 nolu şartnamesine göre çekme testi örnekleri hazırlanmıştır. Örnekler kırılana kadar devam ettirilen çekme testinde iki grubun maksimum çekme dayanıklılığı ve uzama yüzdesi değerleri Mann Whitney U testi kullanılarak karşılaştırılmıştır (α=0.05). Kırılma yüzeyleri stereomikroskop kullanılarak incelenmiştir.</p> <p><strong>Bulgular:</strong> Magnum H60 grubunun maksimum çekme dayanıklılığının (828 ± 17.3 MPa) Biosil F’nin dayanıklılığından (782 ± 51.6) istatistiksel açıdan anlamlı ölçüde yüksek olduğu</p> <p>bulunmuştur (α =0.01). Magnum H60 ve Biosil F gruplarının uzama yüzdeleri sırası ile 6.77 ± 1.62 ve 6.32 ± 2.38 olarak bulunmuştur. İki grubun uzama yüzdeleri arasında anlamlı bir farklılık bulunamamıştır (α =0.496). Kırılma yüzeylerinden alınan stereomikroskop görüntüleri benzerlik göstermektedir. Her iki gruba ait örneklerin kırılma yüzeyinde alaşımın sertleşmesi sırasında oluşmuş porotik yapılar ve çatlaklar izlenmektedir.</p> <p><strong>Sonuç:</strong> Bu çalışmada test edilen Co-Cr alaşımlarının her ikisi de mekanik özellikleri açısından hareketli bölümlü protezlerin ağızda uzun süre kullanımı için uygundur.</p> <strong>Anahtar Kelimeler:</strong> Hareketli bölümlü protezler, Co-Cr alaşımları, maksimum çekme dayanımı, uzama yüzdes

Influence of Layer Thickness on Stress Distribution in Ceramic-Cement-Dentin Multilayer Systems

WOS: 000260087100018PubMed ID: 18833778The effects of dentin and cement thicknesses on stress level and distribution of crack propagation in multilayer complex were analyzed. Custom-designed finite element analysis program based on JL Analyzer was used to analyze the stress distribution and present the maximum principal stress locations. In Zirconia, all the maximum stress values were above 100 MPa. In Empress II, they ranged between 50 and 105 MPa, which were approximately one-third of those of Zirconia. In Feldspathic, the maximum stress values were generally lower than 50 MPa. In all groups with 30 mu m cement thickness, the highest values were observed at the bottom surface. For cement thicknesses at 50, 70, and 100 mu m, maximum stress was found to occur at the top surface. However, changes in dentin thickness did not bring about significant changes in maximum stress values. Results of this study revealed the roles played by the following variables in the failure of a multilayer structure: cement thickness had a Minor influence, dentin thickness exerted no influence, but the thickness and type of ceramic system played a significant role

Dynamic and static load performance of dental biomaterial systems with conical implant-abutment connections

BACKGROUND: The stability of the implant-abutment interface is an important factor that influences load distribution on the marginal bone. OBJECTIVE: In this study, three dental implants with the same connection were subjected to different dynamic loading cycles. The fracture strengths and the horizontal compatibility of implants were assessed. METHODS: Eighty four implant specimens were embedded in a polyacetal cylinder as simulated bone loss of 3 mm from the implant platform. Three of the implants were used to determine the endurance limit. The other specimens were subdivided into four subgroups (n = 6): three for dynamic + static loading, and one for static loading (control group). The tests were performed by applying a compression load. The dynamic loading experiments included three different cycles with endurance upper limit loads at a frequency of 10 Hz. RESULTS: The differences between the fracture strength values of the implant brands were found to be statistically significant. However, there were no meaningful differences between the fracture strength values of implants of the same brand. The specimens of the DTI implant system had the lowest strength (647.9 +/- 41.5 N) and the SEM analysis indicated that the Implantium implant system had the shortest horizontal gaps. CONCLUSIONS: There was a negative correlation between the fracture strengths and size of the microgaps. The importance of these in vitro results needs to be validated by clinical trials because the loads in the mouth can be applied from various angles

Effect of zinc and melatonin supplementation on cellular immunity in rats with toxoplasmosis

The effects of zinc (Zn) and/or melatonin supplementation on cellular immunity were investigated in rats infested with Toxoplasma gondii. Fifty Sprague-Dawley male rats were used for this study. All animals were fed a normal diet, ad libitum, containing 97 mg Zn/kg. They were divided into five experimental groups, as follows. Group I (n = 10) received intraperitoneal injections of zinc sulfate at a dose of 3 mg/kg/d for 3 wk. Group II (n = 10) received intraperitoneal injections of melatonin at a dose of 3 mg/kg/d for 3 wk. Group III (n = 10) received intraperitoneal injections of zinc sulfate (3 mg/kg/d) and melatonin (3 mg/kg/d) for 3 wk. Group IV (n = 10) was infested controls. Group V (n = 10) was healthy controls. There were no differences in the percentage of CD3+ lymphocytes among all groups. For groups I-III, the CD4+ and CD8+ ratios were higher than those of the groups IV and V controls (p < 0.01). Similarly, the total lymphocyte ratios in groups I-III were higher than those of infested and healthy controls (p < 0.01). The total lymphocyte ratios in group III were significantly higher than those of groups I and 11 (p < 0.01). The plasma Zn levels in the supplemented groups were significantly higher than those of control groups IV and V (p < 0.01). These results suggest that melatonin and/or Zn supplementation may activate cellular immunity by stimulating CD4+ and CD8+ production in infected rats with T. gondii

A Modified Technique for Orientation of an Adhesive Retained Ear Prosthesis: Case Report

WOS: 000305320400039Maxillofacial prostheses may be considered as a treatment alternative for congenital or traumatic defects. There are two orientation problems that should be considered during the planning of an ear prosthesis. One of the problems is to determine the right position of prostheses according to symmetric side on the head. The other problem is, if necessary, positioning the implants in reference to the healthy side. Different methods have been proposed in order to deal with these problems. The aim of this study was to introduce a modified method of orientation and to discuss the results with a previously presented investigation

Prenatal Diagnosis of Fetal Hypothyroidism After Maternal Radioactive Iodine Exposure During Pregnancy

A 33-year-old woman with a history of surgically treated papillary thyroid carcinoma was inadvertently given radioactive iodine when she was 16 weeks pregnant. Sonographic examination revealed fetal thyroid hypoplasia, and cordocentesis confirmed fetal hypothyroidism at 22 weeks. The pregnancy was terminated at 24 weeks. We report the first case of fetal thyroid hypoplasia diagnosed by ultrasound and cordocentesis. (C) 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:506-508, 2010; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jcu.2073