PubMed · 3470032
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1987-03-21. Needle-guard holders.. https://doi.org/10.1038/sj.bdj.4806079
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The aim of this study was to determine the removal of dentin produced by number 25 (0.08) Flare files (Quantec Flare Series, Analytic Endodontics, Glendora, California, USA) and number 1 e 2 Gates-Glidden burs (Dentsply - Maillefer, Ballaigues, Switzerland), in the mesio-buccal and mesio-lingual root canals, respectively, of extracted human permanent inferior molars, by means of measuring the width of dentinal walls prior and after instrumentation. The obtained values were compared. Due to the multiple analyses of data, a nonparametric test was used, and the Kruskal-Wallis test was chosen. There was no significant difference between the instruments as to the removal of dentin in the 1st and 2nd millimeters. However, when comparing the performances of the instruments in the 3rd millimeter, Flare files promoted a greater removal than Gates-Glidden drills (p > 0.05). The analysis revealed no significant differences as to mesial wear, which demonstrates the similar behavior of both instruments. Gates-Glidden drills produced an expressive mesial detour in the 2nd and 3rd millimeters, which was detected trough a statistically significant difference in the wear of this region (p > 0.05). There was no statistically significant difference between mesial and lateral wear when Flare instruments were employed.
BACKGROUND AND OBJECTIVES: An Er:YAG laser effectively removes dental hard substance, and causes less pain during tooth preparations than high-speed drilling. This laser was introduced to eliminate the noise, vibration, pressure, and heat associated with the high-speed drilling. However, the difference in tooth vibration caused by the Er:YAG laser and the high-speed drill is unclear. Therefore, the aim of this study was to evaluate tooth vibration obtained with the Er:YAG laser and high-speed drill. STUDY DESIGN/MATERIALS AND METHODS: Each of the five extracted permanent upper first premolars were built up in a plaster box. In this study, a silicone impression material was selected to simulate periodontal tissue. The vibration speed was measured by using a laser Doppler vibrometer. RESULTS: The Er:YAG laser irradiation energy was 50, 100, 145, 199, 300, and 350 mJ. As irradiation energy increased, vibration of the tooth also rose; a high-correlation coefficient was observed between them. We found that only a small amount of the tooth vibration occurred with the Er:YAG laser preparations. The mean vibration speed and standard deviation with the laser were 166 +/- 28 microm/second when the output energy was 145 mJ, whereas those with the high-speed drill were 65 +/- 48 mm/second. The frequency characteristic approached 230 Hz and 5 kHz, respectively. CONCLUSIONS: These results show that the high-speed drilling causes greater tooth vibration and has a frequency spectrum near the high sensitivity of hearing compared to the Er:YAG laser. This suggests a potential factor in provoking pain and displeasure during tooth preparation. Future study to examine the relationship of pain and amount of tooth vibration will be planned.
Information obtained from careful observation of stainless-steel hand file deformation can be a critical step in efficient root canal space debridement. Secondary and tertiary canal curvatures that occur most often in the proximal view have been reported in the literature. Except in teeth that are clinically rotated, there is currently no method for observing the proximal view of root canal systems. This article presents a simple clinical procedure for detecting the three-dimensional anatomy of root canal spaces. We refer to the procedure as file molding.