Studying the mechanics of particle systems in special relativity is one of the most
complex issues. However, this study sets us up to lay the groundwork for building a set of
important laws. The motion of particle masses as a whole was determined b
y their energy,
impulse and static mass. It was also found that the total energy of the system of mutual
action requires taking into account the energies of these mutual acts between the particles.
Contrary to the systems of the mutual acts of collisions, approximate formulas for
interplay between charged particles were determined by studying the collision of
relativistic particles-Compton's effect.
Finally, the case of the movement of the charged particles of weak interacts was
discussed, and the movement of the interconnected particles was discussed through mutual
electromagnetic acts using the concept of mutual action between the particles of the
system.
Aim:
The aim of this study was to compare the weight of debris and irrigant that extruded
apically during the preparation of root canal system using standardized technique, hand
ProTaper, and rotary universal ProTaper.
Materials and Methods:
The
sample was consisted of 30 single rooted teeth, with single canal and apical
foramen, the working length was standardized and the access cavity prepared, each tooth
was fixed with ruper stopper in glass vial contains agar 1.5% to simulate the periapical
tissue. And the vial was fixed in a bigger vial to eliminate any unneccesry contact with the
apparatus. The first vial was weighted before and after preparation.
The sample was randomly divided into three groups, group A Standardized
technique, B Hand ProTaper PTH , C Universal ProTaper PTU.
Result:
The three techniques caused apically extruded debris and irrigants, with statically
significance between Standarized technique and Hand ProTaper(P= 0.024) while the first
caused more debris and irrigants extrusion, also Universal ProTaper caused more extrusion
than Hand ProTaper with statically significance (p= 0.050), but there was no significant
differences between Standarized technique and Universal ProTaper P>0.05.
Conclusion:
Under the condition of this study, it can be concluded that both hand and rotary
preparation technique will cause apical extrusion of debris and irrigants. And PTH was the
least causing of apically extrusion.