Main Article Content
Materials and methods: Ninety upper complete denture bases were constructed for this study. They were divided into two main groups according to the polymerization methods: conventional water bath and experimental autoclave (short and long cycles). Each main group was further subdivided into three subgroups according to the palatal depth (shallow, medium and deep). Furthermore, for each palatal depth; complete denture bases were invested either with dental stone or laboratory silicone. For each upper complete denture, measurements of linear dimensional changes were done by fixation of metallic screws on the tissue surface of the denture base. The distances were measured by using travelling microscope with an accuracy of 0.001 %. The data were statistically analyzed using three way analysis of variance (ANOVA) for three variables, which were (palatal depth, investments and polymerization techniques), LSD test and student T test for comparisons between groups.
Results: There were significant improvements in the dimensional accuracy of denture bases cured with autoclave compared with water bath. Also, silicone investments were a successful alternative to stone, study data shows that short autoclave processing with silicone reduces the magnitude of the linear dimensional changes. On the other hand, long autoclave processing and stone investments were better than silicone in reducing dimensional changes.
Conclusion: The findings of this study indicates that the use of autoclave processing in acrylic curing is a promising alternative to the conventional water bath and leads to better dimensional stability for the finished dentures in all oral configurations and palatal depths. Also, Silicone is more preferable than stone, although it's not as strong investing materials when compared with stone.
Licenses and Copyright
The following policy applies in The Journal of Baghdad College of Dentistry (JBCD):
# JBCD applies the Creative Commons Attribution (CC BY) license to articles and other works we publish. If you submit your paper for publication by JBCD, you agree to have the CC BY license applied to your work. Under this Open Access license, you as the author agree that anyone can reuse your article in whole or part for any purpose, for free, even for commercial purposes. Anyone may copy, distribute, or reuse the content as long as the author and original source are properly cited. This facilitates freedom in re-use and also ensures that JBCD content can be mined without barriers for the needs of research.
# If your manuscript contains content such as photos, images, figures, tables, audio files, videos, etc., that you or your co-authors do not own, we will require you to provide us with proof that the owner of that content (a) has given you written permission to use it, and (b) has approved of the CC BY license being applied to their content. We provide a form you can use to ask for and obtain permission from the owner. If you do not have owner permission, we will ask you to remove that content and/or replace it with other content that you own or have such permission to use.Don't assume that you can use any content you find on the Internet, or that the content is fair game just because it isn't clear who the owner is or what license applies.
# Many authors assume that if they previously published a paper through another publisher, they own the rights to that content and they can freely use that content in their paper, but thatâ€™s not necessarily the case, it depends on the license that covers the other paper. Some publishers allow free and unrestricted re-use of article content they own, such as under the CC BY license. Other publishers use licenses that allow re-use only if the same license is applied by the person or publisher re-using the content. If the paper was published under a CC BY license or another license that allows free and unrestricted use, you may use the content in your JBCD paper provided that you give proper attribution, as explained above.If the content was published under a more restrictive license, you must ascertain what rights you have under that license. At a minimum, review the license to make sure you can use the content. Contact that JBCD if you have any questions about the license. If the license does not permit you to use the content in a paper that will be covered by an unrestricted license, you must obtain written permission from the publisher to use the content in your JBCD paper. Please do not include any content in your JBCD paper which you do not have rights to use, and always give proper attribution.
# If any relevant accompanying data is submitted to repositories with stated licensing policies, the policies should not be more restrictive than CC BY.
# JBCD reserves the right to remove any photos, captures, images, figures, tables, illustrations, audio and video files, and the like, from any paper, whether before or after publication, if we have reason to believe that the content was included in your paper without permission from the owner of the content.