BACKGROUND Accuracy evaluation of navigated image free placement of double cortical fixation buttons for coracoclavicular tunnel position in comparison to conventional drill guide based placement. METHODS Twenty-six patients with acute acromioclavicular joint instability were included in this non-randomized cohort study. All patients were treated with a Double- TightRope technique. In 13 case...

Improving the surface quality of additive manufactured parts like poly lactic acid (+) is an important study that currently being carried out by researchers. To reach high-quality, different conventional and nonconventional methods are applied. In this study, capability ultrasonic vibration in drilling (+)was examined. The process was implemented two methods: vibratory drilling. Then, thrust fo...

Background/Aim During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and tem...

The process of borehole drilling is a nonlinear and many dimensional process. During drilling it is possible occurrence of some complications (for example transition of drilling tool in layer with anomalous pressure). New method of identification of rock layers with anomalous pressure was proposed and tested on real plant data.

SUMMARY The use of composite laminates in complex structures has increased significantly. However, there are still some issues when considering their use, mainly related with machining, leading to some difficulties and lack of acceptance. In this work, a methodology to evaluate drill geometry and feed rate based on thrust force and delamination extension is presented. INTRODUCTION For the past ...

Reaming is a common finishing process for improving the drilled holes surface quality. Choosing an appropriate finishing method in drilling process has a significant effect on the surface quality of holes and in decreasing the process total cost and time. In this study, four similar holes were drilled on the AISI 4340 workpiece with different two pair feed rates. The drilling process was perfor...

A major component of minimally invasive cochlear implantation is atraumatic scala tympani (ST) placement of the electrode array. This work reports on a semiautomatic planning paradigm that uses anatomical landmarks and cochlear surface models for cochleostomy target and insertion trajectory computation. The method was validated in a human whole head cadaver model (n = 10 ears). Cochleostomy tar...

Early erbium and CO2 lasers failed to gain wide acceptance in the dental community because their optical drilling speeds were slower in comparison to the mechanical bur. This has changed in the past few years; much faster ablation speeds are now possible and dental lasers with variable square pulse technology even exceed the drilling speeds of conventional burs. In this paper we report on a cli...

the conventional tunneling procedures for example drilling, charging, blasting, loading and supporting, are highly developed. new tunneling machines have recently come into operation and others are under construction or development. impactors are used in large numbers in the coal mining industry. face-heading machines are successfully used in new tunneling procedures in both soft and medium-har...