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Apparecchiatura termica per rigenerare strumenti endodontici in nichel-titanio deformati.
No full text
[Mechanical properties of nickel-titanium files following multiple heat sterilizations].
No full textThe effect of cycles of sterilization procedures on nickel-titanium (NiTi) endodontic instruments is a serious concern for practitioners. There is no agreement in the literature whether these procedures could adversely affect the mechanical properties of endodontic files, and, consequently, increase the risk of intracanal failure. The purpose of this study was to evaluate the mechanichal resistance of Hero (MicroMega, Besancon, France) instruments, before and after sterilization procedures. Thirty 02, 04, 06 tapered Hero size 30 new instruments were chosen and divided into 3 groups. Group A (control) were tested according to ANSI/ADA Spec.no 28 for torsional resistance, angle of torque and angle at breakage (45 inverted exclamation mark ). Group B files were first sterilized with chemiclave for 10 cycles of 20 minutes at 124 inverted exclamation mark C and then tested as described above. Group C files were first sterilized with glass beads for 10 cycles of 20 sec. at 250 inverted exclamation mark C and then tested as described above. Data were collected and statistically analyzed (t-paired test). Differences among the 3 groups were statistically not significant for both tests. All data were well within Spec.no 28 standard values. From the results of the present study, we may conclude that repeated sterilization procedures do not adversely affect the mechanichal resistance of Hero files
In vitro evaluation of five root canal sealers
No full textAn adequate film thickness is an important property of an endodontic sealer, when used in combination with gutta-percha, to eventually fill minimal voids between gutta-percha and the root canal walls, ensuring an hermetic three-dimensional root canal obturation. The goal of the present study was to evaluate the film thickness of the following five root canal sealers: RSA, Rocanal R4, N2, Bioseal and Acroseal.
METHODS:
The testing procedures strictly followed ANSI/ADA spec. no. 57 for endodontic filling materials. All root canal sealers were mixed at room temperature strictly following mixing procedures advised by manufacturers. A small amount of sealer was placed between two glass plates and load of 147 N was applied vertically on the top glass plate. After 10 min, the thickness of sealers was measured by a micrometer assembled on a stereomicroscope (Lomo MBC 10). Data were collected and statistically analysed.
RESULTS:
Results (expressed in micron) were the following: RSA=9,3 (+/-1), Rocanal R4 95 (+/-12), N2 50 (+/-23), Bioseal 41 (+/-13) and Acroseal =9 (+/-2.55).
CONCLUSIONS:
RSA and Acroseal showed the best results (a statistically significant difference was noted among these sealers and the others). On the other hand Bioseal and (partially) N2 showed values compatible with a valid clinical use, while Rocanal R4 showed values higher than minimum standard values allowed by ANSA/ADA spec. no. 57
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