• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.247-256
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• 2003

The patient had bruxism and epilepsy tendency. Inadequate or unstable posterior support was identified due to severe anterior attrition and decreased occlusal vertical dimension. Prematurities of posterior occlusal and wear facets increased the function of anterior teeth, resulting in severe wear. Wear facets displayed sharply defined peripheries, which are matched on articulated diagnostic casts. Also the patient showed C III malocclusion tendency, and lost some facial contour with drooping corners on the mouth. In this case, the alteration of OVD (Occlusal Vertical Dimention) may provide a biologically compatible adjunct to the treatment such as dentofacial esthetics, improved visual proportion in facial heightand mechanical solutions to the force-management of the masticatory system. The patient requires extensive restorative treatment to regain appropriate function, esthetics and comfort. According to the report by Farhad Fays, the average vertical distance from the maxillary to the mandibular mucolabial reflection in the region of the central incisors is approximately 34mm. However, the vertical distance of this patient was found to be 32mm, which was necessary to add gauge 20-sheets to apply vertical dimension. A removable occlusal overlay splint, which restores OVD to the estimated optimalposition, is the general first trial. The patient was observed periodically for 6 weeks, while appropriate adjustments were made vertical dimension to function. When patient felt comfortable with the splint, the teeth were prepared, and provisional restorations are placed for 3 months. The provisional restoration was fabricated by a diagnostic wax-up. When the patient felt comfortable with the provisional restoration, the final restoration mimics OVD, function, and esthetics that have been developed in the treatment restorations. Restoration of the extremely worn dentition presents a substantial challenge to thedentists. Therefore, careful evaluation of the etiology, history, and factors associated with occlusal vertical dimension should be preceded prior to the appropriate treatment planning.

• The Journal of Korean Academy of Prosthodontics
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• v.18 no.1
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• pp.7-13
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• 1980

The purpose of this study was to evaluate the removable partial denture prescriptions including surveyed crowns and design of component parts sent to the laboratory technician. A total of 351 casess with prescription forms and master cast in maxillary and mandibular semi-edentulous situations collected from dental laboratory by random sampling were selected for this study. The evaluation and study observed here involved the classification of edentulous situations, status of abutment splinting, form of rest seats and guiding plane of surveyed crows, location of maxillary major connectors and tripodig marks on the master casts. Removable partial denture prescriptions contained (1) general request (upper and lower cast framework), (2) types of metal, (3) location of retainer(retention, lingual bracing, rest area, guiding plane surface), (4) location and type of major connector, (5) relief area and amount, (6) and other specific instructions. The following informations based on the classified groups such as Group I was those cases sent with no real prescriptions. They say 'make a partial.' No prescriptions, no thought beforehand, Group II was those cases sent with a minimal prescriptions. They say 'make a partial with clasps on May be some preparations, usually inadequate. Group III was those cases sent with a moderately good prescription. Adequate but could be much better. No tripoding but it tell what clasps go where. Still not good prescriptions. Group IV was good cases, tripoded with adequate prescriptions and a prescription which exactly describes what is expected from the laboratory. The analyzed results were as follows: 1. The normal form of rest seats and guiding plane of surveyed crowns in Class. I and Class. II edentulous situations on the maxillary cast were observed 31.9% and 27.89%, respectively. The abutment teeth and retainer without occlusal rests of Class. I and Class. II were showed 11.58% and 8.86%, respectively. In mandibular cases, the normal form of rest seats and guiding plane of surveyed crowns showed 27.54% and 8.82% in Class. I and Class. II situation. The abutment teeth and retainer without rest seats were showed 15.19%, respectively. 2. The splinted surveyed crowns of Class. I and Class. II maxillary edentulous situations in distal extension cases were showed 34.51% and 28.85%, but 28.52% and 10.29%, respectively. 3. The location and type of maxillary major connector delineated on the master cast were 66 cases (44.89%). 4. The results of 351 cases were classified as Group I 146(41.59%), Group II 115 (32.76%), Group III 57 (16.23%), and Group IV 33 (9.48%). 5. The delineation of abutment tooth for clasping were 176 cases (50.14%) among total of 351 cases. 6. The delineation of height of contour line were showed 45 cases (12.8%) in Group II, 14 cases (3.98%) in Group III and 33 cases (9.40%) in Group IV with total 92 cases (26.21%). 7. In surveying procedure, the delineation of tripoding marks and reference line were showed 17 cases (4.84%).

• The Journal of Advanced Prosthodontics
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• v.2 no.4
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• pp.148-153
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• 2010

PURPOSE. The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables. MATERIALS AND METHODS. Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured. RESULTS. The mean values for variables were significantly higher in type I bone than in type II bone (P < .01). In type I bone, the ISQ values in the drill group were significantly higher than in the laser group (P < .05). In type II bone, the ISQ values in the laser group were significantly higher than in the drill group (P < .01). In both type I and type II bone, the maximum insertion torque, total energy, and total angular momentum values between the drill and laser groups did not differ significantly (P ${\geq}$ .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696). CONCLUSION. Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.283-292
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• 2022

For fixed prosthetic treatment using implants, implants must be placed in a suitable location for prosthetic treatment. During surgery, minimally invasive prosthetic restoration is possible using a flapless method using a surgical guide. The patient in this case was an 86-year-old male patient who wanted treatment due to discomfort when using conventional dentures. Due to systemic disease, the patient had difficulty using removable local dentures, so full dentures for the maxilla and fixed implants for the mandible were restored. Because there is a high risk of bleeding due to systemic disease, the implant was placed in a flapless method using a surgical guide. Finally, prostheses were fabricated with maxillary full denture and mandibular screw-retained zirconia, and this report shows satisfactory esthetic and functional recovery.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.308-315
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• 2023

In the case of a patients who have lost the centric stop and have a staggered occlusion of the residual teeth, various movements occur when the denture is loaded. Implant placement is necessary to reinforce the retention, support, and stabilization elements to reduce denture movement. However, in this case, considering the patient's age, aversion to surgery, and bone loss, implants were not placed and restoration was performed with a removable partial denture. In this case, it is important to set the correct mandibular position for restoration because the patient has a habit of chewing with the remaining teeth. In this case, a stable mandibular position was established using a gothic arch tracing, and good results were obtained by restoring with partial dentures, so this is reported.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.279-285
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• 2017

Defects due to mandibulectomy often cause hard and soft tissue loss and result in esthetic problems and functional disorders such as mastication, swallowing, and pronunciation. After the mandibular reconstruction, several complications including loss of alveolar bone can cause limitations in maintenance or supporting of removable prosthesis. For these patients, implant-supported fixed restorations have been an appropriate prosthetic restorative method. In this case report, we report the patient who underwent mandibulectomy and mandibular reconstruction owing to oral cancer, and then restored the current dentition functionally and aesthetically by applying zirconia frameworks and monolithic zirconia crowns by computer-aided design and computer-aided manufacturing.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.440-450
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• 2003

Statement of problem : The joints of removable partial denture alloys have failed frequently after routine usage. Purpose : The purpose of this study was to evaluate the mechanical properties of the laser welded Co-Cr alloys. Material and method : For this study 20 Co-Cr specimens were casted and 10 of them were seperated on the middle area and laser welded with Alpha laser welding machine(Siro Lasertec, Pforzheim, Germany). Rest of them which were as cast, were used as a control group. For the section of the experimental specimens, wire cutting machine was used to make a even gap of the all specimens. Laser welding was done with manufacturer's instrunction and tested each specimen by Instron Machine. Tensile strength, 0.2% yield strength and % elongations were recorded. Fractured surfaces were investigated with SEM. Results : The results were as follows : 1. The tensile strength of the laser welded group(617.7MPa) was about 75% of the as cast group(820.4MPa). It had stastically significant differences(p<0.05). 2. The % elongation of the experimental group was 6.6 which was lower than the control group(14.3). 3. Fracture of the experimental group occured in the welded surface and showed many voids. In contrast, the fracture surface of the control group was showed rough surfaces without any voids. Conclusion : The tensile strengths of the as-cast joints were higher than those for the laser welded joints, and the % elongation of the experimental group was lower than the control group. Porosity was found in laser-welded joints.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.349-355
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• 2020

The use of an obturator prosthesis for patients with maxillary defects is a common treatment method to improve their oral function and achieve esthetic satisfaction. However, due to various difficulties and complexities, conventional methods for fabricating dental obturators continue to pose a challenge for dentists and patients, as well as laboratory technicians. CAD-CAM technologies may make it simple to fabricate maxillofacial prostheses including hollow obturators, which could improve comfort for clinicians by reducing burdensome manipulations. In addition, patients without a specialist in their vicinity will be able to be treated via cooperation between a nearby general practitioner and a distant prosthodontist. The aim of this clinical report is to investigate the possibility of using digitally fabricated maxillofacial prostheses that can be designed in one location, and manufactured in another in clinical situations.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.107-118
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• 2007

Statement of problem: Implant-type distractor uses a removable distraction device that has an appearance similar to that of a dental implant and utilizes many of the same techniques for placement as are used for dental implants. Material and method: In this study, 48 implant type titanium distractors were inserted into the osteotomized alveolar bone of 12 beagle dogs. After a 7-day latency period, the alveolar bone was augmented by 5mm vertically at a rate of 1.0 mm/day. The dogs were sacrificed after 4weeks, 8weeks and 12 weeks for radiographic, histologic, and histomorphometric analysis. Result: Copper equivalent value showed significant difference between 4 weeks and the other weeks(8, 12 weeks)(p<0.05). But there was no significant difference between maxillary and mandibular groups. In the bone to metal contact analysis, there was a significant difference between 4 weeks and 12 weeks(p<0.05). On the contrary, there was no significant difference between maxilla and mandible. The bone area showed significantly higher values in 12 weeks compared to 4 weeks(p<0.05). Histologically mineralization began at the host bone margins. At 12 weeks, increasing accumulation of $Ca^{++}$ element was confirmed. Conclusion: From the results above, the new bone formation was increased according to consolidation period. Especially there was significant difference between 4 weeks and 12 weeks(p<0.05). Implant type distractors used in this study to augment vertical ridge defect may prove to be a clinically useful treatment option in selected cases.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.305-310
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• 2012

It is a great challenge for dentists to do prosthetic restorations of a patient with reduced occlusal vertical dimension (OVD). Proper determination of the OVD is significant. An 85-year-old male patient came in with missing right maxillary posterior teeth. After diagnostic wax-up, reversible provisional prostheses were used to evaluate the new OVD in the maxilla and mandible. After that, the patient was evaluated clinically based on the criteria of esthetic, phonetic, and OVD. After 8 weeks, teeth with excessive wear were treated with root canal therapy and fiber post and core and irreversible provisional prostheses were done. After 8 weeks of observation period, final restorations with fixed partial dentures and removable partial dentures were made. Throughout the follow-up period of 6 months, no symptoms related with increased OVD and mechanical complications were observed.