02852cam a2200337 a 4500 EG-GiCUC 20250223032455.0 191209s2018 ua dh f m 000 0 eng d EG-GiCUC eng EG-GiCUC eng Deposite Ph.D Cai01.24.03.Ph.D.2018.Ah.E Ahmed Youssry Elhawary Effect of Ercr: YSGG 2.7 nm laser on debonding of CAD/CAM endocrowns / Ahmed Youssry Elhawary ; Supervised Ahmed Abbas , Tarek Harhash تأثير اربيوم كروميوم ليزر على قوة الترابط لدى التيجان ذات تمديد بالقناة العصبية بمساعدة الحاسب الآلى Cairo : Ahmed Youssry Elhawary , 2018 83 P. : charts , facsimiles ; 25cm Thesis (Ph.D.) - Cairo University - National Institute of Laser Enhanced Sciences - Department of Lasers Application in Medical Biological The present study investigated the effect ErCr:YSGG laser on the debonding of all ceramic endocrown restorations. A total of 30 caries free human molar teeth were collected.All teeth were placed in epoxy resin by using a custom-made device.To standardize the preparation of all samples, decoronation of the teeth was done using a straight handpiece affixed to a surveyor and was done at a level 1mm above the cemento-enamel junction. Each abutment was scanned, and the copings were designed using interactive CAD software. An occlusal extension with an occlusal hole was added to the coping design to facilitate the coping removal during the test.Samples were then divided in to 2 groups: Group (A) (n=15): endocrowns subjected to ErCr:YSGG laser application.Group (B) (n=15): endocrowns not subjected to laser (control).After cementation of the samples, Group A was subjected to ErCr:YSGG laser application while Group B was not.Testing the samples All samples were then subjected to thermocycling at 5000 cycles, then the cemented specimens were mounted in a jig attached to a universal testing machine to measure the retentive pull out tensile load of the material. A tensile mode of force was applied via materials testing machine at a crosshead speed of 5 mm/min up to pull out the coping until cement failure. The maximum pull out load was recorded automatically in Newton via the computer software connected to the testing machine.Mode of failure was examined using photos with scanning electron microscope Issued also as CD CAD software CAD/CAM Ercr: YSGG 2.7 nm laser Ahmed Abbas , Supervisor Tarek Harhash , Supervisor http://172.23.153.220/th.pdf Nazla Revisor Shimaa Cataloger ddc TH 75727 75727 ddc 0 CUCL cl210 2024-02-11 Cai01.24.03.Ph.D.2018.Ah.E 01010110080264000 2023-09-22 00:00:00 TH ddc 0 CUCL cl2u8 2024-02-11 Cai01.24.03.Ph.D.2018.Ah.E 01020110080264000 2023-09-22 00:00:00 80264.CD CD