• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.468-473
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• 2014

PURPOSE. This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. MATERIALS AND METHODS. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by $10^{\circ}-20^{\circ}$ and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (${\alpha}=.05$). RESULTS. Precision discrepancies for the canine, premolar, and molar were $3.7{\mu}m$, $3.2{\mu}m$, and $7.3{\mu}m$, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were $6.2{\mu}m$, $11.2{\mu}m$, and $21.8{\mu}m$, respectively, indicating the poorest trueness for the molar (P=.007). CONCLUSION. In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.359-363
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• 2013

This article describes the treatment provided to a patient with the maxillary anterior teeth exhibiting severe secondary caries beneath the previous restoration and a white spot lesion on the adjacent incisor. Two implants were placed after extraction of hopeless teeth with the guided bone regeneration technique. A white spot lesion of the adjacent incisor was treated with minimally invasive treatment. This clinical report describes the multidisciplinary treatment for the white spot lesion and esthetic restoration of missing anterior teeth.

• Journal of English Language & Literature
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• v.58 no.6
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• pp.1215-1233
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• 2012

This essay is an attempt to critique the notion of hybridity that has so far facilitated a liberal multiculturalist reading of White Teeth. For an alternative framework, it posits the multiethnic subject-making to examine in what ways the novel questions the premises of liberal multiculturalism. In this vein, this study suggests that Smith throws some significant light on the underside of holding multiple racial/ethnic identities while not bypassing its utopian possibilities. In case of the first-generation male characters, their crossracial/homosocial friendship becomes a platform for a mode of egalitarian belonging across the racial divide. It further implies a symbolic union between working-class white and nonwhite immigrant. The younger generation, in contrast, undergoes problems of racial, ethnic, cultural affiliations in far more complicated ways than the older one. Above all, White Teeth demonstrates the subtle workings of liberal multiculturalism, within which the younger characters are constructed to be a multiethnic subject in varied modes. It delineates the formation mainly by exploring the persisting legacies of Britain's imperial history that partake in their subject-making. The novel, in doing so, obliquely suggests that the younger generation is to confront the past that is a seminal part of their present life rather than have the freedom to throw it away to be a carefree member of a multicultural society.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.452-456
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• 2013

PURPOSE. The aim of this study was to evaluate the repeatability of the digitizing of silicon rubber impressions of abutment teeth by using a white light scanner and compare differences in repeatability between different abutment teeth types. MATERIALS AND METHODS. Silicon rubber impressions of a canine, premolar, and molar tooth were each digitized 8 times using a white light scanner, and 3D surface models were created using the point clouds. The size of any discrepancy between each model and the corresponding reference tooth were measured, and the distribution of these values was analyzed by an inspection software (PowerInspect 2012, Delcamplc., Birmingham, UK). Absolute values of discrepancies were analyzed by the Kruskal-Wallis test and multiple comparisons (${\alpha}$=.05). RESULTS. The discrepancy between the impressions for the canine, premolar, and molar teeth were $6.3{\mu}m$ (95% confidence interval [CI], 5.4-7.2), $6.4{\mu}m$ (95% CI, 5.3-7.6), and $8.9{\mu}m$ (95% CI, 8.2-9.5), respectively. The discrepancy of the molar tooth impression was significantly higher than that of other tooth types. The largest variation (as mean [SD]) in discrepancies was seen in the premolar tooth impression scans: $26.7{\mu}m$ (95% CI, 19.7-33.8); followed by canine and molar teeth impressions, $16.3{\mu}m$ (95% CI, 15.3- 17.3), and $14.0{\mu}m$ (95% CI, 12.3-15.7), respectively. CONCLUSION. The repeatability of the digitizing abutment teeth's silicon rubber impressions by using a white light scanner was improved compared to that with a laser scanner, showing only a low mean discrepancy between $6.3{\mu}m$ and $8.9{\mu}m$, which was in an clinically acceptable range. Premolar impression with a long and narrow shape showed a significantly larger discrepancy than canine and molar impressions. Further work is needed to increase the digitizing performance of the white light scanner for deep and slender impressions.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.1
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• pp.31-39
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• 2004

For the prosthodontic results which are compatible with esthetics to be fulfilled, the first prerequisite would be periodontal intervention and stability, the second one may be functional competency and the ultimate goal should be ascribed to esthetic considerations. Other words, esthetic dentistry is a whole entity which encompasses the biological stability of the periodontium, physical accuracy of the prosthodontic structure and finally, the beauty which can be found in natural dentition. It also implies the harmonized lip line which reveals the well-balanced tooth morphology and health gum profiles (Red-White Esthetics). Largely, there lie some differences in the input system of the 3-dimentional data from the prepared abutments between respective computer-assisted systems available now. But the manufacturing systems (CAM) are very similar between them, to say, comprise numeric control systems with whole 3-dimensional milling units according to the restorations to be made. Now the author is going to present CAD/CAM Zirconia All Ceramic Restoration on the topics for the Red-White Esthetics, periodontal control and maintenance, treatment for the discolored teeth, post & core build-up works for the devitalized teeth, characteristics of the Zirconium oxide All Ceramics, fabrication procedures, clinical considerations and its application to diverse clinical situations.

• Restorative Dentistry and Endodontics
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• v.2 no.1
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• pp.50-54
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• 1976

16 healthy teeth extracted have been selected and their color and structural change have been observed at the fixed temperatures of $200^{\circ}F$., $400^{\circ}F$., $600^{\circ}F$., and $800^{\circ}F$. respectively at the intervals of 10min. 30min and 60min. The results were as follows: 1) $200^{\circ}F$ Groop: At the 60 minutes interval, crown surface shows pattern simliars to mottled teeth and roots take on light yellowish colar and interglobular dentin tends to be rough. 2) $400^{\circ}C$ Groop: at the 30 minutes interval, cracks begin to show in the direction of long axis of the teeth and crown surface have been observed on the verge of fracture at the 60 minutes interval. 3) $600^{\circ}F$ Groop: Crowns take on grayish-white color thoroughout 10, 30 and 60 minutes intervals and roots reveal black color. Moreover the seperation of enamel from dentin has been confirmed at the 60 minutes interval and inner dentin has changed black. 4) $800^{\circ}F$ Groop: Crowns take on the same grayish-white color as at the $600^{\circ}F$ at the 10, 30 and 60 minutes intervals and roots reveal gray color at the 30 and 60 minutes intervals, while parts of the crown have fractured at the 10 minutes interval. Inner dentin has turned gray at the 60 minutes interval.

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.85-93
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• 2001

The purpose of this study was to evaluate the effects of commercial home-tooth bleaching agents on the color of tooth. Twenty five sound extracted teeth were randomly divided into five groups. The color differences between before and after treatment with five types of tooth bleaching agents (7.5% hydrogen peroxide Nite White $Excel^{(R)}$, 10% carbamide peroxide Nite White $Excel^{(R)}$, 16% carbamide peroxide Nite White $Excel^{(R)}$, 10% carbamide peroxide Insta-BriteTM, 20% carbamide peroxide Insta-$Brite^{TM}$) were evaluated. The results were as follows: 1. By 2 week home tooth bleaching agent applications, the values ($L^*$) of bovine teeth increased as high as 4.38 $\sim$ 8.80 when comparing to those of the samples before treatment, and the color difference (${\Delta}E^*$) showed as high as 10.16 $\sim$ 15.04. 2. 16% carbamide peroxide Nite White Excel induced significantly greater ${\Delta}L^*$ than other test edgroups except for 7.5% hydrogen peroxide Day White Excel, and significantly greater ${\Delta}E^*$ than other tested groups by 2 week bleaching agent treatments (p<0.01). 3. 16% carbamide peroxide Nite White Excel(${\Delta}L^*$=8.80, ${\Delta}E^*$=15.04) induced significantly greater ${\Delta}L^*$ and ${\Delta}E^*$ than 10% carbamide peroxide Nite White Excel(${\Delta}L^*$=5.01, ${\Delta}E^*$=10.16)(p<0.01), but significant difference between 10% carbamide peroxide Insta-Brite(${\Delta}L^*$=4.38, ${\Delta}E^*$=10.51) and 20% carbamide peroxide Insta-Brite(${\Delta}L^*$=5.63, ${\Delta}E^*$=11.23) was not shown in ${\Delta}L^*$ and ${\Delta}E^*$(p>0.01). 4. 16% carbamide peroxide Nite White Excel(${\Delta}L^*$=8.80, ${\Delta}E^*$=15.04) which were applied in night time induced significantly greater ${\Delta}L^*$ and ${\Delta}E^*$ than 7.5% hydrogen peroxide Day White Excel(${\Delta}L^*$=8.47, ${\Delta}E^*$=12.75) which were applied in day time. Conclusions: These results demonstrate that all the commercial home-tooth bleaching agents have appreciable bleaching effect on teeth, and the effects of home-tooth bleaching agents which are used during night time are affected by content of carbamide peroxide. Especially the whitening effect of home tooth bleaching agents that are used through night time is greater than that of short time-applying tooth bleaching agent.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.469-477
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• 2021

For successful restoration of maxillary anterior implants, both pink esthetics and white esthetics must be satisfied. For pink esthetic part, the role of appropriate provisional prosthesis restoration is important, and for white esthetic part, the color and shape of the definitive prosthesis is important. Multilayer zirconia can be used for natural tooth appearance due to the higher transparency of the incisal area compared to the conventional monolithic zirconia. Therefore, in this case, white esthetic part was achieved through multilayer zirconia after recovering function and esthetics through appropriate provisional prosthesis in a patient who lost the maxillary anterior teeth.

• The korean journal of orthodontics
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• v.1 no.1
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• pp.15-20
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• 1970

The author investigated on the responses of pulp and dentine following tooth movements. The material consisted of fifty-four intact teeth from twenty-seven adult white rats. The half of the teeth were employed as controls and the other half served as experimental group. These teeth were moved with forces ranging from 30 grams to 120 grams for from 3 to 7 days. All these were extracted immediately after the force was relieved. The main pulp changes in the experiment were vacuolization of the pulp tissue and circulatory disturbances. The magnitude of the force had an important role. In addition to these changes, the resorption in dentine and cementum was observed, which was related to the magnitude of the force and the duration of experiment.

• The Journal of the Korean dental association
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• v.50 no.8
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• pp.507-515
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• 2012

The purpose of this article is to discuss the effect of aging on the treatment of replantation and transplantation of teeth in old patients. I case of replantation and 2 cases of transplantations in old patients are reported in this article. Patients aged 65 and over are included. They had several problems such as periapical lesion, crack or foot fractures. In those cases, the replantation and transplantation were treatment of choice. White ProRoot MTA was used in apical retrograde filling and perforation repair. After replantation and transplantation of teeth, follow-up visits showed signs of healing in 3 cases. Considerations and indications for replantation and transplantation are not much affected by age. Old patients are aware that replantation and transplantation can be performed comfortably and that age is not a factor in prediction success.