ENDO Fracture Limits of Maxillary Fourth Premolar Teeth in Domestic Dogs Under Applied Forces REITER, SOLTERO RIVERA ET AL Flashcards
WHAT WAS THE PURPOSE OF THE STUDY AND WHAT TYPE OF STUDY WAS IT?
A cadaveric study was performed to investigate the external mechanical forces required to fracture maxillary fourth premolar teeth in domestic dogs and describe a clinically relevant model of chewing forces placed on functionally important teeth in which fracture patterns
What was the mean maximum force sustained by the teeth at the point of fracture ?
1,281 N (± 403 N)
In descending order of frequency of occurrence what were the most common fractures?
Complicated crown fracture (50%) Uncomplicated crown fracture ( 25%) Complicated crown/root fracture (20.8%) Uncomplicated crown root fracture (4.2%)
What was the only independent variable which was significant?
crown height to diameter ratio which showed that a decreased ratio increases tooth fracture resistance.
What is the reported prevalence of tooth fracture ? To what percentage does this increase in maxillofacial trauma patients?
20-27% increases to 67-85% in MF trauma.
In this paper what bite forces are cited as being produced in dogs? And what sort of pulling forces can occur when all four canines are engaged?
13- 1394N 480 - 1200 N
What is this device and what does it do?
Computer-generated drawing that depicts the aluminum jig used to create compressive loading in a controlled manner. The device was holding each pot at an angle of 60° (θ) with respect to the ground (A). Right maxillary fourth premolar tooth with surrounding alveolar bone seated inside a polycarbonate cylinder filled with PMMA. The pot is held by the aluminum device, and the steel actuator is coming into contact with the occluso-palatal aspect of the main cusp of the tooth at the onset of mechanical testing (B).
How did crown height to diameter ratio affect the maximum force to fracture?
For every one unit increase in the crown height to diameter ratio, the maximum force was decreased by 3,137 N
What was a limitation of the study and how could thi be addressed in the future?
The study is limited by the use of point force application and testing to load to failure. This copiuld be improved by using a 4-point bending model and cyclic loading to failure. A 4-point bending model would employ forces on the cusps of maxillary fourth premolar teeth to provide downward force vectors on the outside of the object while the cusps of mandibular first molar teeth would provide an upward force vector on the inside of the object.
