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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

OPTIMIZATION OF DRILL DESIGN AND COOLANT SYSTEMS DURING DENTAL IMPLANT SURGERY

Kalidindi, Varahalaraju 01 January 2004 (has links)
Dental implants are an effective alternative for the replacement of missing teeth. The success of the implant depends on how well a bone heals around the implant, a process known as osseointegration. However, excessive heat generated during the bone drilling will cause cell death and may prevent osseointegration of the implant, resulting in early failure. There are many factors which contribute to the heat generation during drilling. Experiments were carried out to investigate the affect of variable drilling factors on heat generation during drilling operation. Natural bone is not an ideal material for such research, as it varies widely in density and other parameters of interest.. It would be desirable to have a more uniform and consistent material to use in such studies. However, such a material must be similar to bone to allow the results to be extrapolated to the clinical situation. The current study describes and validates a model for use in such studies. Polymethylmethacrylate (PMMA) is the material chosen for our studies. A theoretical model was developed to study the effect of different drilling parameters on temperature rise during drilling operations. Comparison of observed results obtained from experiments was made with the results from theoretical study. Comparison of results for PMMA and human bone are also shown explaining how PMMA material can be substituted for human bone. The results suggest that the PMMA model is an acceptable surrogate for bone in such studies.
2

Technologické, ekonomické a ekologické aspekty obrábění s vysoce výkonným chlazením / Technological, economical and ecological aspects of high efficient cooling

Hort, Martin January 2009 (has links)
The diploma thesis is aimed to the influence of the high-pressure and low-pressure coolant system according to the machining operation. The comparison was carried out with different types of materials and cutting tools using the main machining operations – turning, milling, and drilling. The study is focused on the chip and heat removal from the cutting zone, tools life and wear of the tools. A description of the basic principle of the high-pressure coolant system meant is described in this thesis. The economical analysis of the high-pressure compared to low-pressure system was determined in the last part of this work.

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