OBJECTIVE To assess if the screw design (self-drilling/self-tapping) and the pilot hole tapping could affect the insertion torque and screw pullout strength of the screw used in anterior fixation of the cervical spine. METHODS Forty self-tapping screws and 20 self-drilling screws were inserted into 10 models of artificial bone and 10 cervical vertebrae of sheep. The studied parameters were th...

Rotary drilling belongs to the key methods of rock separation not only in mining, but also in wider areas of geotechnologies 1, 2 . The most efficient separation of rocks is in so-called volume area which can be achieved with the correct choice of work tool and work mode while taking into account the geomechanical properties of rock separation. Theoretical research of rock separation by rotary ...

Multiplicity of the effective factors in drilling reflects the complexity of the interaction between rock mass and drilling bit, which is followed by the dependence of parameters and non-linear relationships between them. Rock mass or, in other words, the formation intended for drilling, as the drilling environment, plays a very essential role in the drilling speed, depreciation of drilling bit...

background: laparoscopic ovarian drilling (lod) is an alternative method to induce ovulation in polycystic ovary syndrome (pcos) patients with clomiphene citrate (cc) resistant instead of gonadotropins. this study aimed to compare the efficacy of unilateral lod (ulod) versus bilateral lod (blod) in cc resistance pcos patients in terms of ovulation and pregnancy rates. materials and methods: in ...