during root canal preparation,
intracanal debris could extrude apically. The purpose of this in
vitro study was to detect the effect of preparation technique on the
amount of apically extruded debris.
A synthetic fibre from polyolefins wastes was obtained as follow:
1. From polyethylene and polypropylene wastes in various
percentages to get the optimum percentage in the fibre
2.From polyethylene and polypropylene gralunar.
We used an indirect
recycling operation using extrusion by the
extruder.
The obtained fibre was tested mechanically, physically and
chemically and the results demonstrate that the production of these
fibers are available laboratorially and industrially.
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.
Aluminum Alloy 6063 is used widely in extrusion industry for
building and automobile applications. Aluminum billet is
manufactured usually by vertical continuous casting technique and direct water cooling. 5 different casting temperatures 660, 680,
700, 720, 740Cº, besides 5 different casting speeds 100, 112, 125, 138, 150 mm/min to control cool water feeding are chosen. It has noticed that the increase of casting temperature and decreasing of casting speed has a good effect on improving billet quality which contribute later on improving the hardness and mechanical properties of extruded aluminum profiles.
