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Full-Text Articles in Dental Materials
A Comparison Of Two Rapid Palatal Expansion Appliances And Their Effect On Palatal Cross-Sectional Area, William D. Scott
A Comparison Of Two Rapid Palatal Expansion Appliances And Their Effect On Palatal Cross-Sectional Area, William D. Scott
Loma Linda University Electronic Theses, Dissertations & Projects
Two rapid palatal expansion appliances, acrylic-free and acrylic-reinforced, were compared for their effect on the cross-sectional area of the palate. Two groups, twenty-five patients in each, were selected so that they would match as closely as possible with regards to age and sex distribution. The pre-treatment and post-treatment maxillary models were duplicated, and this duplicate model was then trimmed in a specific manner to allow the cross-sectional area between the first permanent molars to be compared. The results indicate that there is no difference, at the five percent level of significance, between these two appliances. It is concluded that the …
Force Loss In Retraction Springs At 37°C As Affected By Time, Roger Edward Clawson
Force Loss In Retraction Springs At 37°C As Affected By Time, Roger Edward Clawson
Loma Linda University Electronic Theses, Dissertations & Projects
Closed helix retraction springs fabricated from .016 X .016 inch Blue Elgiloy, Permachrome Standard stain less steel, and Multiphase orthodontic wire were tested at 37°C in their heat and nonheat treated condition to determine force relaxation properties. Electronic equipment consisting of load cells, regulated power supply, and an automatic recording device were used to measure force changes which occurred in the wire samples over a seven day period. A constant temperature was maintained by an ethylene glycol and water circulator. A temperature probe and an electronic thermometer monitored the 37°C water bath surrounding the wire samples. The data was graphed …