• The Journal of Korean Academy of Prosthodontics
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• v.62 no.3
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• pp.243-252
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• 2024

When fabricating definitive implant-supported fixed prostheses in upper and lower completely edentulous patients, it is crucial to get information about the vertical dimension, jaw relationship, implants, abutments and gingival contour. In this case, temporary prostheses were used to take the information. The temporary prosthesis was scanned outside of the mouth so that it increased the efficiency of scanning it. During the scan of the prosthesis, a scan zig which connected both posterior parts of the prosthesis was used to minimize the scan errors. We report this case because we obtained satisfactory functional and esthetic results by using the digital technology.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.236-244
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• 2011

Purpose: This study was aimed to compare the margin and internal fitness of 3-unit zirconia bridge cores fabricated by several CAD/CAM systems using replica technique. Materials and methods: Three unit-bridge models in which upper canine and upper second premolar were used as abutments and upper first premolar was missed, were fabricated. Fourty models were classified into 4 groups (Cerasys$^{(R)}$ (Group C), Dentaim$^{(R)}$ (Group D), KaVo Everest$^{(R)}$ (Group K), $Lava^{TM}$ (Group L)), and zirconia cores were fabricated by each company. Sixteen points were measured on each abutment by replica technique. Statistical analysis was accomplished with two way ANOVA and Dunnett T3 (${\alpha}$=.05). Results: In most systems, there was a larger gap on inter margin than outer margin. In the Group K, overall fitness was excellent, but the incisal gap was very large. In the Group C, marginal gap was significantly larger than Group K, but overall internal gap was uniform (P<.05). The axial gap was under $100\;{\mu}m$ in all system. The difference between internal and external gap was small on Group L and C. However, internal gap was significantly larger than external gap in Group D (P<.05). The fitness of canine was better than second premolar among abutments (P<.05). Conclusion: The marginal and internal gap was within the clinically allowed range in all of the three systems. There was a larger gap on second premolar than canine on internal and marginal surface. In most systems, there was a larger gap on occlusal surface than axial surface.

• Journal of Technologic Dentistry
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• v.38 no.2
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• pp.57-62
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• 2016

Purpose: The purpose of this study was to assess precision of crown prostheses that were fabricated by using 2 kinds of bur or 3 kinds of bur. Methods: The crowns were fabricated by using the first molar of the right maxillary in this study. The abutments that were prepared were scanned by using a scanner and designed by using CAD software. Based on the crown design, NC data were created with CAM software. The created NC data were used while fabricating the crown prostheses by using 5-axis milling machine. Scanning was done for the internal and external surface of the completed crown prostheses and 3-dimensional measurement was conducted for precision assessment. Results: The $RMS{\pm}SD$ value for the external surface of the crown prostheses that was fabricated by using two burs and three burs were $28.5{\pm}4.1{\mu}m$ and $19.1{\pm}2.8{\mu}m$, respectively; and the value for two burs were bigger than that for three burs with statistical significance (p<0.001). The $RMS{\pm}SD$ value for the internal surface of the crown prostheses that was fabricated by using two burs and three burs were $14.9{\pm}1.9{\mu}m$ and $13.3{\pm}2.5{\mu}m$, respectively; and the value for two burs were bigger than that for three burs but with no statistical significance. Conclusion: Based on this study, the prostheses that were fabricated by using 3 bur presented better stability compared to those that were fabricated by using 2 bur and statistically significant difference was found only in the external surface.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.1
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• pp.11-19
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• 2019

Purpose: This study evaluated the usability of and satisfaction with two types of computer-aided design (CAD) software among users who had experience with dental implant CAD software and those who did not. Materials and Methods: Dental technicians (n = 20) who had previous experience with dental implant CAD Software and students from the College of Dentistry (n = 12) who had never designed implant custom abutments were asked to evaluate two types of CAD Software, Exocad and Deltanine. In addition, the participants were asked to fill out a structured questionnaire (Section 1: Entering basic information and retrieving files; Section 2: Setting conditions before abutment design; Section 3: Setting abutment design; and Section 4: Overall satisfaction). For the statistical analysis of the collected data, Mann-Whitney U test was used (${\alpha}=.05$). Results: The ease of design and satisfaction with the implant CAD Software, evaluated with respect to 21 statements divided into four Stages, were significantly higher for Exocad in both groups for Secion 1. For Sections 2 and 3, participants with experience evaluated Deltanine to be significantly better. For Section 4, both groups evaluated Exocad Software to be better. Conclusion: Overall, the Exocad Software was evaluated as having better usability and offering greater satisfaction. However, in terms of performance in the core of the design process, i.e. Sections 2 and 3, Deltanine was rated higher by the experienced users. Thus, if the user interface design parts are supplemented, Deltanine CAD Software could be put to a wider use in clinics.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.234-243
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• 2015

Developing of digital technique, it is possible to fabricate implant prostheses for edentulous area using intraoral 3-dimentional information throughout implant diagnosis and treatment process. It is being changed that from the method using CAD/CAM, producing prostheses by model scanning after conventional impression and model processing, to the method of fabricating implant provisional restorations and customized abutments by digital impression after connecting digital impression copings (scanbody) and implant fixtures without models. But, this digital method has not been actively used for implant prostheses not yet. Specially, it is short of intraoral digital impression cases for immediate provisional restorations of the maxillary anterior implants. The gingival contour impression of maxillary anterior area is very important for esthetic restorations. Accordingly, in this case report, the using a digital impression coping (scanbody) and digital impression by CEREC Omnicam (Sirona, Bensheim, Germany) or Trios (3shape, Copenhagen, Denmark) were introduced for immediate provisional restorations in 3 cases needed a single implant restoration in maxillary anterior area. The clinical results were satisfactory on the convenience and accuracy of digital impression technique and the good esthetics of final restorations.

• The Journal of the Korean dental association
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• v.49 no.2
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• pp.77-84
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• 2011

The benefits of implant supported overdenture are readily apparent for the fully edentulous patients and have been well documented, however, there is deficiency of the studies regarding the combination of implants with removable partial dentures for partially edentulous patients. The purpose of this article is to review the literature concerning implants with removable partial dentures and evaluate the evidence for this clinical approach. Through many clinical case reports and studies we have searched from a broad variety of journals, we present the six considerations needed to contemplate respecting implants with removable partial denture in partially edentulous patients. First, the connection between abutment tooth and removable partial denture has to be rigid and the link between implant and removable partial denture should be hinged. Second, a mesial rest acts better in the point of force distribution for distal extension removable partial denture and splinting between implants is also a favorable choice. Third, T bar has an advantage for implants which are used as abutments in distal extension removable partial denture. Forth, as we all known functional impression is better way to reproduce movement for distal extension removable partial denture. Fifth, indirect retainer and guiding plane on the proximal surfaces of terminal abutment teeth are important in preventing denture base lifting. Sixth, implants in conjunction with removable partial denture is superior in the esthetic and phonetic as well as cost-effective point of view. We also suggest that which place we should install implants for force distribution and which diameter and length of implants should be used. in this review article, we recommend to locate the implant near of the abutment tooth for esthetics or near of first molar position for good stress distribution. The diameter and length of implant also influence to stress distribution. When we compare to conservative partial denture, patients go for removable partial denture using implants due to convenience, better support and retention according to several studies. But it is true that we need to study more on this subject and collect long term follow up cases before we discuss on it. So it is enough to bring this subject into the surface of prosthetic treatment by this article.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.7-13
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• 2020

Purpose: This study was to evaluate marginal and internal discrepancy of 3-unit fixed dental prostheses (FDP) fabricated by subtractive manufacturing and additive manufacturing. Materials and methods: 3-unit bridge abutments without the maxillary left second premolar were prepared (reference model) and the reference model scan data was obtained using an intraoral scanner. 3-unit fixed dental prostheses were fabricated in the following three ways: Milled 3-unit FDP (MIL), digital light processing (DLP) 3D printed 3-unit FDP (D3P), stereolithography apparatus (SLA) 3D printed 3-unit FDP (S3P). To evaluate the marginal/internal discrepancy and precision of the prosthesis, scan data were superimposed by the triple-scan protocol and the combinations calculator, respectively. Quantitative and qualitative analysis was performed using root mean square (RMS) value and color difference map in 3D analysis program (Geomagic control X). Statistical analysis was performed using the Kruskal-Wallis test (α=.05), MannWhitney U test and Bonferroni correction (α=.05/3=.017). Results: The marginal discrepancy of S3P group was superior to MIL and D3P groups, and MIL and D3P groups were similar. The D3P and S3P groups showed better internal discrepancy than the MIL group, and there was no significant difference between the D3P and S3P groups. The precision was excellent in the order of MIL, S3P, and D3P groups. Conclusion: Within the limitation of this study, the 3-unit fixed dental prostheses fabricated by additive manufacturing showed better marginal and internal discrepancy than the those of fabricated by subtractive manufacturing, but the precision was poor.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.271-279
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• 2019

There are several unfavorable conditions regarding alveolar bone condition that may compromise the denture patient's satisfaction. Chewing efficiency may not be satisfactory when alveolar bone is deficient, and the denture stability could hardly be achieved when alveolar bone shape is irregular. Implant overdenture can be useful to provide satisfactory denture experience compared to conventional denture. The attachment for implant overdenture can be classified into bar attachment and solitary attachment. When the positions of the implants are in the mandibular anterior region, bar attachment may be favorable to obtain a rigid support of the entire denture. When implants are distributed both on anterior and posterior region, a solitary attachment could be considered for ease of removal and maintenance. This report presents implant overdenture cases with the patients that had unilateral mandibular alveolar bone atrophy conditions. Different abutments were chosen based on the individual patient's mandibular alveolar bone condition and the treatments were successful in terms of patient satisfaction.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.495-505
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• 2019

This study reported the treatment of a patient with excessive worn dentition and limited maxillo-mandibular space for restoration, utilizing the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. After the thorough examination of the patient's occlusal vertical dimension (OVD), full mouth rehabilitation was planned with increase of the OVD. The patient was satisfied with the provisional restorations establishing the increased OVD. The horizontal and vertical data of the patient's jaw relation that the provisional restorations contained were transferred to the definitive metal ceramic fixed prostheses by double scanning and three-dimensional printing. After the fixed restorations were cemented to the abutments, electronic surveying and three-dimensional printing were used to fabricate metal frameworks for the patient's removable partial dentures. The mandibular definitive removable prostheses were delivered to the patient's mouth and the full mouth rehabilitation procedures were completed. The digital technologies used for this case produced fixed and removable restorations satisfactory in masticatory, phonetic and aesthetic functions to both the patient and the dental clinician.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.157-164
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• 2024

A variety of digital technologies are being used throughout the entire implant treatment process of diagnosis, surgery, impression, design, and fabrication of prostheses. In this case, using a digital surgical guide, sinus floor elevation was performed without complications, and the implants were placed in the planned position. After the healing period for osseointegration, CAD-CAM (Computer-aided design-Computer-aided manufacturing) customized abutments and provisional prostheses were delivered. While using the provisional prosthesis, occlusal change was observed. To transfer the intermaxillary relationship and abutment position that reflect occlusal change and axial displacement, double scanning and abutment-level digital impressions were taken. Abutment superimposition was used to capture the subgingival margin without gingival retraction. Then, the definitive prosthesis was designed and fabricated with digital system. We report a case applying digital system, to achieve the predictable result as well as the efficient treatment process from implant surgery to fabricating prosthesis in the posterior area.