Canal Shaping Ability And Wear Resistance Of NiTi LightSpeed Instruments: Effect Of Rotational Speed. (An invitro study)
Reham Mohammad Said Abdullah Siam.;
Abstract
The present investigation was carried on to study the behavior of NiTi LightSpeed rotary instrument during root canal preparation using two specified rotational speeds namely 750 and 2000 r.p.m., also to study the wear criteria of used instrument relative to the unused one.
Seventy two LigbtSpeed instruments of sizes 20 through 4 7.5 were used
in the preparation of 54 root canals in 27 mesial roots of freshly extracted
'
human mandibular molars. The mesial root canals had curvature between 15-
. .
30 ° as selected and traced by Digora. All MB canals were prepared by the
LightSpeed instrument at 750 r.p.m., while ML at 2000 r.p.m. to examine the effect of rotational speed on the instrument's performance.
Before instrumentation, roots were embedded in clear acrylic, sectioned
at 2, 4, and 6mm level from their apices and the canal openings were filled
. . :
with colored wax. The root sections were held and reassembled by a specially constructed metal muffle. After mechanical preparation canals' cross sections
were again filled with colored wax for post-instrumentation 'photographing at
, . "
• the same distance and magnification. The pre- and post-instrumentation
images were scanned, digitized and subjected to computer analysis and calculations of canal area, center and displacement distance.
Results showed statistically insignificant differences between canal area
after preparation using 750 r.p.m. or 2000 r.p.m. Lightxpeed instrument remained nearly centralized with insignificant canal transportation which when occurred, it took a mesial-buccal direction.
Many wear criteria were noted in the unused LightSpeed instruments examined under stereomicroscope and SEM. The most common of which were metal strips, fretting, pitting, blunting of cutting edge, microfractures and corrosion in descending order which either increased after 5 canals preparation and continued to increase after 9 canals like blunting of cutting
Seventy two LigbtSpeed instruments of sizes 20 through 4 7.5 were used
in the preparation of 54 root canals in 27 mesial roots of freshly extracted
'
human mandibular molars. The mesial root canals had curvature between 15-
. .
30 ° as selected and traced by Digora. All MB canals were prepared by the
LightSpeed instrument at 750 r.p.m., while ML at 2000 r.p.m. to examine the effect of rotational speed on the instrument's performance.
Before instrumentation, roots were embedded in clear acrylic, sectioned
at 2, 4, and 6mm level from their apices and the canal openings were filled
. . :
with colored wax. The root sections were held and reassembled by a specially constructed metal muffle. After mechanical preparation canals' cross sections
were again filled with colored wax for post-instrumentation 'photographing at
, . "
• the same distance and magnification. The pre- and post-instrumentation
images were scanned, digitized and subjected to computer analysis and calculations of canal area, center and displacement distance.
Results showed statistically insignificant differences between canal area
after preparation using 750 r.p.m. or 2000 r.p.m. Lightxpeed instrument remained nearly centralized with insignificant canal transportation which when occurred, it took a mesial-buccal direction.
Many wear criteria were noted in the unused LightSpeed instruments examined under stereomicroscope and SEM. The most common of which were metal strips, fretting, pitting, blunting of cutting edge, microfractures and corrosion in descending order which either increased after 5 canals preparation and continued to increase after 9 canals like blunting of cutting
Other data
| Title | Canal Shaping Ability And Wear Resistance Of NiTi LightSpeed Instruments: Effect Of Rotational Speed. (An invitro study) | Other Titles | قدرة تشكيل القناه ومقاومة التآكل باستخدام ادوات النيكل تيتانيوم لايت سبيد تأثير سرعة الدوران (دراسة معملية) | Authors | Reham Mohammad Said Abdullah Siam. | Issue Date | 2003 |
Attached Files
| File | Size | Format | |
|---|---|---|---|
| B15660.pdf | 1.02 MB | Adobe PDF | View/Open |
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