• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.406-414
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• 2003

Chemomechanical approach to caries removal was introduced in order to preserve the maximum amount of sound tooth structure. The efficacy of chemomechanical caries removal was assessed using microcomputed tomography which offers 3 dimensional data without destroying the tooth, and the V works program. In group 1, the density values of the sound dentin, carious dentin, and remaining dentin after chemomechanical treatment were analyzed. In group 2, the density values of the sound dentin, cavity wall prepared using high speed bur, and the remaining dentin after additional $Carisolv^{TM}$ gel application on the same cavity were analyzed. The results were as follows; 1. The density value of the remaining dentin after the $Carisolv^{TM}$ treatment was 81.8% of the sound dentin(p < 0.001). 2. The density value of the remaining dentin after the conventional rotary instrument showed no statistically significant difference from that of the sound dentin(p = 0.234).

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.254-261
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• 2020

Purpose: The purpose of this study was to assess the marginal and internal fit of interim crowns fabricated by two different manufacturing method (subtractive manufacturing technology and additive manufacturing technology). Materials and Methods: Forty study models were fabricated with plasters by making an impression of a master model of the maxillary right first molar for ceramic crown. On each study model, interim crowns (n = 40) were fabricated using three types of 3D printers (Meg-printer 2; Megagen, Zenith U; Dentis, and Zenith D; Dentis) and one type milling machine (imes-icore 450i; imes-icore GmbH). The internal of the interim crowns were filled with silicon and fitted to the study model. Internal scan data was obtained using an intraoral scanner. The fit of interim crowns were evaluated in the margin, absolute margin, axial, cusp, and occlusal area by using the superimposition of 3D scan data (Geomagic control X; 3D Systems). The Kruskal-wallis test, Mann-Whitney U test and Bonferroni correction method were used to compare the results among groups (α = 0.05). Results: There was no significant difference in the absolute marginal discrepancy of the temporary crown manufactured by three 3D printers and one milling machine (P = 0.812). There was a significant difference between the milling machine and the 3D printer in the axial and occlusal area (P < 0.001). The temporary crown with the milling machine showed smaller axial gap and higher occlusal gap than 3D printer. Conclusion: Since the marginal fit of the temporary crown produced by three types of 3D printers were all with in clinically acceptable range (< 120 ㎛), it can be sufficiently used for the fabrication of the temporary crown.