• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.561-574
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• 1998

The purposes of this study were to observe the difference in the root canal wall after hand instrumentation or engine-driven Ni-Ti instrumentation under the scanning electron microscope, and to evaluate the apical leakage provided by continuous wave of canal filling technique with or without root canal sealer and smear layer. Twenty recently extracted human maxillary anterior teeth were instrumented with K-type files or engine-driven Ni-Ti files, Quantec series 2000$^{TM}$ and irrigated with 5.25% NaOCl alone or 15% EDT A and final flush of 5.25% NaOCl. After the instrumentation and flushing, teeth were split in half with a knife and a mallet. They were then examined with a scanning electron microscope Forty-four recently extracted human maxillary anterior teeth were divided into four groups with and without smear layer and then warm vertical canal filling using System-B with or without sealer. The extent of leakage was scored after immersion in India ink for 1 week. The results were as follows: 1. No significant difference of smear layer was observed between K-type file-instrumented group and engine-driven Ni-Ti file-instrumented group. 2. A group without smear layer showed significantly less apical leakage than a group with smear layer when sealer was used for the canal filling (p<0.01). 3. There was no significant difference between a group without sealer and smear layer and a group without sealer and with smear layer (p<0.01). 4. In groups without smear layer, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01). 5. When root canals were irrigated with NaOCl alone, a group with sealer showed significantly less apical leakage than a group without sealer (p<0.01).

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.348-355
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• 2009

Statement of problem: Although the use of colorimeter to improve the accuracy of tooth color measurement has increased, it is real situation that there is almost no comparative study about the accuracy among various colorimeters. Purpose: The purpose of this study is to compare the accuracy of porcelain color reproducibility using ShadeEye-Ncc dental chroma meter (Shofu Inc., Kyoto, Japan) and Shadepilot$^{TM}$ system (Degudent Inc., Hanau, Germany). Material and methods: Color of 2M2 and 3M2 shade tap of Vitapan 3D Master shade guide were measured using the above two colorimeters. Porcelain specimens were fabricated through this data. The porcelain systems used were Vintage Halo Porcelain system with ShadeEye-Ncc dental chroma meter, and VitaOmega900 Porcelain system with Shadepilot$^{TM}$ system. Colors of shade tap models and porcelain specimen were measured with spectrophotometer, and calculated delta E based on the results. Results: The following results were obtained. 1. Shadepilot$^{TM}$ system showed more suitable porcelain color reproducibility compared to ShadeEye-Ncc dental chroma meter (P <.05). 2. The result showed the difference of porcelain color reproducibility according to shade of Shade tap which is model. More suitable porcelain color reproducibility was shown at 3M2 shade tap than at 2M2 shade tap (P <.05). 3. The average of ${\Delta}E*$ of porcelain specimens which was made by the two colorimeters was 4.44-6.14, so the difference of shade was shown through the naked eye. Conclusion: Shadepilot$^{TM}$ system showed more suitable porcelain color reproducibility. When using ShadeEye-Ncc dental chromameter, it will be necessary to improve accuracy through coloring various parts of the whole tooth.