Background: The features of a preparation that prevent castings from being uncemented, debonded, or cement failures, which are one of the top three reasons for casting replacement, are known as retention and resistance forms.
The goal of this study is to determine the difference between a degree of taper that was really achieved in a clinical context and the textbook-recommended degree of taper. It also looked examined how resistance and retention shape are related to the degree of tooth preparation taper.
Materials and Methods: A dental laboratory provided scanned digital pictures of 114 die preparations for all ceramic restorations (n = 114). All of the photos were digitally processed using Adobe Photoshop® software to determine the degree of taper (angle of convergence) of each preparation, and the resistance shape was measured using the Zuckerman's circle and Lewis perpendicular methods.
The overall average degree of taper was determined to be 20.9° (range, 2–80°) in the current study, which is higher than most prior studies' recommendations and also higher than the textbook ideal of 3 to 6°. The average degree of taper for maxillary teeth was 17.56° (anterior 10.50°, posterior 23.7°), whereas it was 25.22° (anterior 15°, posterior 28.45°) for mandibular teeth. The resistance shape was present in 61 of the 64 studied photos of maxillary teeth, whereas it was absent in three. 38 of the 50 mandibular teeth examined had resistant form, while the remaining 12 did not. Regardless of the arch, all of the anterior teeth showed resistance.
Conclusion: There was a strong relationship between the degree of taper and resistance and retention form, which was inversely proportional to each other. Because of different considerations in the actual clinical condition, the recommended "degree of taper" is not always clinically possible as indicated in textbooks.
Clinical Importance: The study provides
scientific background on the relationship between the degree of taper and
resistance and retention form, which was discovered to be inversely
proportional. The recommended "degree of taper," as advised in
textbooks, is not always realistically possible, and it is influenced by a
variety of modifying or limiting elements in the particular clinical setting.
Author(S) Details
Alex M. Muruppel
Department of
Prosthodontics and Implantology, PMS College of Dental Science & Research,
Thiruvananthapuram Kerala, India.
Joyce Thomas
Department of Prosthodontics, Al Azhar Dental College Thodupuzha, Kerala,
India.
Sudeep Saratchandran
Department of Prosthodontics and Implantology, PMS College of Dental
Science & Research, Thiruvananthapuram Kerala, India.
Dinesh Narendran
Department of Prosthodontics and Implantology, PMS College of Dental
Science & Research, Thiruvananthapuram Kerala, India.
Sheeba Gladstone
Department of Prosthodontics and Implantology, PMS College of Dental
Science & Research, Thiruvananthapuram Kerala, India.
Milen M. Rajeev
Department of Prosthodontics, Mar Baselios Dental College Ernakulam,
Kerala, India.
View Book:- https://stm.bookpi.org/IDMMR-V5/article/view/5588
No comments:
Post a Comment