Accuracy of virtual models in the assessment of maxillary defects

Kıvanc Kamburoglu,Sebnem Kursun,Cenk Kılıc,Tuncer Özen 대한영상치의학회 2015 Imaging Science in Dentistry Vol.45 No.1

Purpose: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm3 (FOV60); 2) 80×80 mm FOV, 0.160 mm3 (FOV80); and 3) 100×100 mm FOV, 0.250 mm3 (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

Health Beliefs Concerning Breast Self-examination of Nurses in Turkey

Sevinc Tastan,Emine Iyigün,Ayse Kılıc,Vesile Unver 한국간호과학회 2011 Asian Nursing Research Vol.5 No.3

Purpose: The purpose of the study was to evaluate the health beliefs regarding breast self-examination (BSE) and their relationship with age, educational status and history of breast cancer in the family among nurses working in a university hospital. Methods: A cross-sectional design was used, with a convenience sample of 381 nurses at a military university hospital in Ankara in Turkey. Data were collected by using a personal data form and the Champion’s Health Belief Model Scale. Descriptive statistics, logistic regression, Mann-Whitney U test and Kruskal Wallis Test were conducted. Results: The proportion of nurses reported doing BSE regularly is 47.2%. Controlling variables such as age,body mass index, the age at first birth, breast cancer in the family history and educational background,we found that the subscales of the health belief model, BSE benefit (OR ¼ 0.782), self-efficacy (OR ¼ 0.919), and risk perception (OR ¼ 0.114) have statistically significant effects on the risk of not making BSE. Conclusion: It is important to be aware of the health beliefs of nurses regarding BSE so that their own health can be protected and improved. Beneficial attitudes and behaviors of nurses regarding BSE will enable them to provide more effective services to women regarding breast cancer. Understanding the nurses’ health beliefs, attitude and behavior that are influential to make BSE will guide nursing practices towards early diagnosis of breast cancer at the societal level.

Evaluation of the resin cement thicknesses and push-out bond strengths of circular and oval fiber posts in oval-shapes canals

Tugrul Aslan,Halil İbrahim Kılınc,Burak Sagsen,Kerem Kılıc,Ozgur Er 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.1

PURPOSE The aim of this study was to evaluate whether the push-out bond strength varies between oval and circular fiber posts, and to examine the effect on the resin cement thicknesses around the posts. MATERIALS AND METHODS Eighteen mandibular premolar roots were separated into two groups for oval and circular fiber posts systems. Post spaces were prepared and fiber posts were luted to the post spaces. Roots were cut horizontally to produce 1-mm-thick specimens. Resin cement thicknesses were determined with a metallographic optical microscope and push-out tests were done. RESULTS No significant differences were observed in terms of push-out bond strength between the oval and circular fiber posts (P>.05) The resin cement thicknesses of the oval posts were greater than those of the circular posts group in the coronal, middle and apical specimens (P<.05). CONCLUSION In the light of these results, it can be stated that resin cement thickness does not affect the push-out bond strength.

Annealing of Co-Cr dental alloy: effects on nanostructure and Rockwell hardness

Bulent Piskin,Hasan Suat Gokce,Cumhur Sipahi,Selim Kılıc,Semra İde,Elif Hilal Soylu,Simel Ayyıldız 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.4

PURPOSE The aim of the study was to evaluate the effect of annealing on the nanostructure and hardness of Co-Cr metal ceramic samples that were fabricated with a direct metal laser sintering (DMLS) technique. MATERIALS AND METHODS Five groups of Co-Cr dental alloy samples were manufactured in a rectangular form measuring 4 × 2 × 2 mm. Samples fabricated by a conventional casting technique (Group I) and prefabricated milling blanks (Group II) were examined as conventional technique groups. The DMLS samples were randomly divided into three groups as not annealed (Group III), annealed in argon atmosphere (Group IV), or annealed in oxygen atmosphere (Group V). The nanostructure was examined with the small-angle X-ray scattering method. The Rockwell hardness test was used to measure the hardness changes in each group, and the means and standard deviations were statistically analyzed by one-way ANOVA for comparison of continuous variables and Tukey's HSD test was used for post hoc analysis. P values of <.05 were accepted as statistically significant. RESULTS The general nanostructures of the samples were composed of small spherical entities stacked atop one another in dendritic form. All groups also displayed different hardness values depending on the manufacturing technique. The annealing procedure and environment directly affected both the nanostructure and hardness of the Co-Cr alloy. Group III exhibited a non-homogeneous structure and increased hardness (48.16 ± 3.02 HRC) because the annealing process was incomplete and the inner stress was not relieved. Annealing in argon atmosphere of Group IV not only relieved the inner stresses but also decreased the hardness (27.40 ± 3.98 HRC). The results of fitting function presented that Group IV was the most homogeneous product as the minimum bilayer thickness was measured (7.11 Å). CONCLUSION After the manufacturing with DMLS technique, annealing in argon atmosphere is an essential process for Co-Cr metal ceramic substructures. The dentists should be familiar with the materials that are used in clinic for prosthodontics treatments.

Use of fibrin glue in preventing pseudorecurrence after laparoscopic total extraperitoneal repair of large indirect inguinal hernia

Onder Surgit,Nadir Turgut Cavu?o?lu,Murat Ozgur Kılıc,Yılmaz Unal,Pınar Nergis Ko?ar,Duygu ?cen 대한외과학회 2016 Annals of Surgical Treatment and Research(ASRT) Vol.91 No.3

Purpose: Seroma is among the most common complications of laparoscopic total extraperitoneal (TEP) for especially large indirect inguinal hernia, and may be regarded as a recurrence by some patients. A potential area localized behind the mesh and extending from the inguinal cord into the scrotum may be one of the major etiological factors of this complication. Our aim is to describe a novel technique in preventing pseudorecurrence by using fibrin sealant to close that potential dead space. Methods: Forty male patients who underwent laparoscopic TEP for indirect inguinal hernia with at least 100-mL volume were included in this prospective clinical study. While fibrin sealant was used to close the potential dead space in the study group, nothing was used in the control group. The volume of postoperative fluid collection on ultrasound was compared between the groups. Results: Patient characteristics and the volumes of hernia sac were similar between the 2 groups. The mean volume of postoperative fluid collection was found as 120.2 mL in the control group and 53.7 mL in the study group, indicating a statistical significance (P < 0.001). Conclusion: Minimizing the potential dead space with a fibrin sealant can reduce the amount of postoperative fluid collection, namely the incidence of pseudorecurrence.