• 대한치과기공학회지
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• 제41권2호
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• pp.81-86
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• 2019

Purpose: The purpose of the present study was to compare the internal fit of two different temporary restorations fabricated by dental CAD/CAM system and to evaluate clinical effectiveness. Methods: Composite resin tooth of the maxillary first molar was prepared as occlusal reduction(2.0mm), axial reduction(1mm offset), vertical angle(6 degree) and chamfer margin for a temporary crown and duplicated epoxy die was fabricated. The epoxy dies were used to fabricate provisional restorations by CAD/CAM milling technique or 3D-printing technique. The inner data from all crowns were superimposed on the master die file in the 'best-fit alignment' method using 3D analysis software. Statistical analysis was performed using a Wilcoxon's rank sum test for differences between groups. Results: It showed that the internal RMS(Root Mean Square) values of the additive group were significantly larger than those of other group. No significant differences in internal discrepancies were observed in the temporary crowns among the 2 groups with different manufacturing method. Conclusion: All the groups had the internal fit within the clinical acceptable range (< $50{\mu}m$). The continuous research in the future to be applied clinically for the adaptation of additive manufacturing technique are needed.

• 대한치과기공학회지
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• 제22권1호
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• pp.49-55
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• 2000

In manufacturing the all-ceramic crown whick look close to natural teeth, the effectiveness of the improved technique is expectected the technique of the heat treatment of gold plating coating die was experimented of a refractory cast model. The following results were obtainde 1. An advantage of build up on east die with out manufacturing veneer, crown, core, or masking(reduction of technical process, and retrenchment of time and money) 2. Esthetically more close to natural teeth than other technique 3. Easy to remove a refractors cast die 4. In manufacturing ceramo-metal crown the enomous effectiveness was obtainde on applying in the areas of cervical margin, the metal surface, and in the treatment of pinhole.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권2호
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• pp.122-124
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• 2022

Various techniques are well documented to obtain anatomic reduction, such as reduction forceps, manual reduction, or a combination of these methods. However, these techniques have inherent drawbacks. We propose a new intra-operative technique for anatomic reduction using screw-wire traction for open reduction and internal fixation of mandibular fractures.

• 대한심미치과학회지
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• 제17권1호
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• pp.50-54
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• 2008

• 한국치위생학회지
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• 제9권2호
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• pp.111-124
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• 2009

This study analyzes through the review of literature and laws the exposure time, clinical frequency, and radiation exposure of intraoral and extraoral radiography as well as of panoramic radiography performed by dental hygienists in dental clinics, compares the dental radiology curriculums of radiological science and dental hygiene departments, and proposes the expansion of dental hygienists' radiography operations. The radiology curriculums were compared between the radiological science and dental hygiene departments of colleges. For new analysis by radiography for dental diagnosis, the exposure time, radiation absorbed dose, effective dose, and number of days of natural radiation were compared by the type of oral radiation films and radiographical techniques proposed by domestic and international studies. The exposure time of panoramic radiography is 15 seconds and it takes about two minutes for completion, whereas the exposure time of the standard radiography is 0.2~0.8 seconds and it takes 10 times longer for completion of the radiography of full mouth than the panoramic radiography. The standard radiography can cause distortions of radiation at severely curved parts of dental arch and palatopharyngeal reflex. However, panoramic radiography can be performed even for lock jaw patients, causes less inconvenience to patients and is much simpler than the standard radiography. The percentage of dental clinics where radiography is performed by dental hygienists was 92.0%, and the percentage of standard film radiography by dental hygienists was 98% whereas the percentage of panoramic radiography by dental hygienists was 92%. For the absorbed dose which is an indicator of radiation exposure, the When the effective dose which is an indicator of the danger of radiation exposure was converted to the number of days of natural radiation, it was 3.3 days for panoramic radiography, but 13.9 days for the full mouth standard radiography by bisecting angle technique which was 4.2 times longer than the panoramic radiography. There were two colleges that had a dental radiology course with two credits in the departments of radiological science. The credits for dental radiology courses in the department of dental hygiene ranged varied by college, ranging from 3 to 8; on average, the theory course was 2.2 credits and the practice course was 2.02 credits. To summarize the above results, the percentage of dental clinics where panoramic radiography is performed by dental hygienists under the guidance of dentists is high. Panoramic radiography has become an essential facility for dental clinics. It is faster than standard film radiography and less dangerous due to low radiation exposure. Panoramic radiography is a simple mechanical job that does not require training of oral radiography by radiotechnologist. Because panoramic radiography is one of major operations which must be performed at all times in dental clinics, it must be designated as intraoral technique rather than extraoral technique, or legalized for inclusion in the scope of operations of dental hygienists.

• Journal of Korean Dental Science
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• 제6권1호
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• pp.4-12
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• 2013

Purpose: This study sought to verify the usefulness of mini-implant and surgical steel wire in the treatment of mandibular fracture through the objective identifi cation of the change of bone structure and bone density before and after reduction by evaluating radiological change through fractal analysis when mandibular fracture is treated using mini-implant and surgical wire. Materials and Methods: This study looked at 45 patients (males: 38, female: 7) diagnosed with mandibular fracture in the oral and maxillofacial surgery division of Chung-Ang University Dental Hospital and who received open reduction and intra-osseous fi xation. Result: The average fracture dimension values were higher for the group of the patients who had mini-implants and surgical wire treatment. Conclusion: Based on the results of the study on the usefulness of the reduction technique using mini-implant and surgical steel wire in the treatment of mandibular fracture through the fractal analysis method, the reduction technique using mini-implant and surgical steel wire is regarded as an effective method of minimizing the gap between mandibular fracture fragments.

• The Journal of Advanced Prosthodontics
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• 제9권3호
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• pp.159-169
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• 2017

PURPOSE. The purposes of this study were to evaluate the marginal and internal gaps, and the potential clinical applications of three different methods of dental prostheses fabrication, and to compare the prostheses prepared using the silicone replica technique (SRT) and those prepared using the three-dimensional superimposition analysis (3DSA). MATERIALS AND METHODS. Five Pekkton, lithium disilicate, and zirconia crowns were each manufactured and tested using both the SRT and the two-dimensional section of the 3DSA. The data were analyzed with the nonparametric version of a two-way analysis of variance using rank-transformed values and the Tukey's post-hoc test (${\alpha}=.05$). RESULTS. Significant differences were observed between the fabrication methods in the marginal gap (P < .010), deep chamfer (P < .001), axial wall (P < .001), and occlusal area (P < .001). A significant difference in the occlusal area was found between the two measurement methods (P < .030), whereas no significant differences were found in the marginal gap (P > .350), deep chamfer (P > .719), and axial wall (P > .150). As the 3DSA method is three-dimensional, it allows for the measurement of arbitrary points. CONCLUSION. All of the three fabrication methods are valid for measuring clinical objectives because they produced prostheses within the clinically acceptable range. Furthermore, a three-dimensional superimposition analysis verification method such as the silicone replica technique is also applicable in clinical settings.

• 대한치과기공학회지
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• 제24권1호
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• pp.107-126
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• 2002

The first function of occlusion is mastication. Therefore the functional restoration of occlusal surface is very important. The restoration of occlusal surface is three method as wax bite technique, F.G.P. technique, cone technique. Many dental technician is using compound method. I am using compound method of wax bite technique and cone technique. I have knew common point on each teeth during I have waxing up wax pattern. So I studied on the design waxup technique for mandible molar occlusion. The results of the study were as follows; 1. The dam wax up method can restore axial contour of teeth very easy and make short working time of wax pattern. 2. The height of dam must be same with cusp of adjacent teeth. 3. Automatically the contour of tooth is appeared if the contour of dam is relationship with cuspid line of adjacent teeth. 4. The height of contour of buccal, lingual surface is formed natural curve to add fluid wax by gravitation. 5. The development groove of mandible first premolar is appeared V form. 6. The development groove of mandible second premolar is appeared Y form. 7, The development groove of mandible first molar is appeared M form. 8. The development groove of mandible second molar is W form. 9. The embrasure is formed to carve around contact point area as round convex. It affects to axial form of tooth. 10. The buccal, lingual groove of molar is formed parallel with direction of teeth arrangement.

• The Journal of Advanced Prosthodontics
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• 제3권2호
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• pp.106-109
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• 2011

Oral cancer treatment involves the surgical removal of all or part of the maxilla, leaving the patient with a defect that compromises the integrity and function of the oral cavity. The postoperative restoration of esthetics, deglutition, and speech shortens recovery time in the hospital and expedites the patient's return to the community as a functioning member. The surgical obturator is the proven treatment option in such situations. This article describes a simple technique to fabricate a surgical obturator that restores patient's original dentition and facial and palatal tissue form. The obturator fabricated with this technique utilizes the vacuum formed index of patient's original tissue form and duplicated partly in heat and partly in auto polymerizing acrylic resin. Duplication of the original tissue form helps patient to minimize the immense physiological trauma immediately after the surgical resection. The obturator fabricated with this technique supports soft tissues after surgery and minimizes scar contracture and disfigurement, and thus may have a positive effect on the patients' psychology.

• 대한치과의사협회지
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• 제37권7호통권362호
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• pp.530-535
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• 1999

Detailed finishing of the occlusion is a clinical skill that has become difficult with the development of fixed appliances. Accuracy of bracket placement definitely improves with indirect technique, Several methods for the placement of orthodontic brackets on dental casts are currently used in the indirect bonding technique. These include attachment by means of bonding resins, adhesive tapes or sticky wax. This article presents the indirect procedures of our clinic, which use paste-paste chemically cured composites. Detailed laboratory and clinical procedure for dual tray method and other application of indirect bonding will be presented.