• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.232-239
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• 2016

Purpose: In this paper, we introduce a wide clinical application of root resection therapy and additional benefits on the next prosthetic or dental implant treatment procedures in the age of dental implants. Materials and Methods: Additional clinical benefits of root resection were monitored by clinical and radiographic evaluation. Results: No complication was reported in all the cases, and the favorable results of root resection were maintained for long period. Conclusion: In compromised multirooted teeth, variety clinical treatment modality should be considered for enhancing the reconstruction of alveolar ridge around root resected in preparation for next implantation.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.280-285
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• 2019

PURPOSE. The present study was designed to examine the clinical fit of fixed dental prosthesis fabricated by the milling-sintering method using a presintered cobalt-chromium alloy. MATERIALS AND METHODS. Two single metal-ceramic crowns were fabricated via milling-sintering method and casting method in each of the twelve consecutive patients who required an implant-supported fixed prosthesis. In the milling-sintering method, the prosthetic coping was designed in computer software, and the design was converted to a non-precious alloy coping using milling and post-sintering process. In the casting method, the conventional manual fabrication process was applied. The absolute marginal discrepancy of the prostheses was evaluated intraorally using the triple-scan technique. Statistical analysis was conducted using Mann-Whitney U test (${\alpha}=.05$). RESULTS. Eight patients (66.7%) showed a lower marginal discrepancy of the prostheses made using the milling-sintering method than that of the prosthesis made by the casting method. Statistically, the misfit of the prosthesis fabricated using the milling-sintering method was not significantly different from that fabricated using the casting method (P=.782). There was no tendency between the amount of marginal discrepancy and the measurement point. CONCLUSION. The overall marginal fit of prosthesis fabricated by milling-sintering using a presintered alloy was comparable to that of the prosthesis fabricated by the conventional casting method in clinical use.

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.338-343
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• 2020

PURPOSE. The present study aimed to investigate the relationships between the crown form of the upper central incisor and their labial inclination, overbite, and overjet. MATERIALS AND METHODS. Maxillary and mandibular casts of 169 healthy dentitions were subjected to 3D dental scanning, and analyzed using CAD software. The crown forms were divided into tapered, square, and ovoid based on the mesiodistal dimensions at 20% of the crown height to that at 40%. The degree of labial inclination of the upper central incisor was defined as the angle between the occlusal plane and the line connecting the incisal edge and tooth cervix. The incisal edges of the right upper and lower central incisor that in contact with lines parallel to the occlusal plane were used to determine the overbite and overjet. One-way ANOVA was performed to compare the labial inclination, overbite, and overjet among the crown forms. RESULTS. The crown forms were classified into three types; crown forms with a 20%/40% dimension ratio of 1.00±0.01 were defined as square, >1.01 as tapered, and <0.99 as ovoid. The labial inclination degree was the greatest in tapered and the least in square. Both overbite and overjet in tapered and ovoid were higher than those in square. CONCLUSION. Upper central incisor crown forms were related to their labial inclination, overbite, and overjet. It was suggested that the labial inclination, overbite, and overjet should be taken into consideration for the prosthetic treatment or restoring the front teeth crowns.

• The Journal of the Korean dental association
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• v.37 no.1 s.356
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• pp.62-68
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• 1999

Patients who present with severe maxillary bone loss Secondary to trauma or resorption provide a unique diagnosis and difficulty in implant installation. To solve this problem, various bone grafting methods and graft materials can be used in these compromised cases. But for the patients required wide reconstruction, autogenous iliac bone has been used widely because of easy harvesting of much corticocancellous bone. Usually, implant installations are performed 6-12 months later after grafting. but this method necessary long treatment period and additional surgery. To avoid this disadvantages, bone grafting with immediate implant installations are frequently used. But special care is necessary to prevent postoperative complication in this method. We present three cases of veneer grafting with immediate implant installation. These patients had a knife-edge shaped alveolar bone due to labial alveolar bone loss. We reconstructed this alveolar bone with veneer grafting with iliac bone and performed immediate implant installation. There was no complications during healing periods in these three cases. Six months later, we found good survival of grafting bone and osseointegration of these implants, so we could perform prosthetic treatment successfully.

• The Journal of the Korean dental association
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• v.52 no.12
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• pp.771-782
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• 2014

Introduction: This study researched the clinical application of immediate functional loading technique about implant survival rate in the completely edentulous and suggested our protocol about surgical & prosthetic procedure. Materials and methods: 32 consecutive patients participated in this study. A total of 242 implants were inserted. In test group, 144 implants were inserted in 19 patients with immediate functional loading with occlusal contact. In control group, 98 implants were inserted in 13 patients and conventional loading was done after 4~6 months. Result: In the immediately loaded implants group, overall cumulative survival rate was 98.6%.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.47-54
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• 1981

Dental porcelains are widely used for restorative material because of its excellent esthetic property. But according to contact with natural teeth or metal in oral cavity, the porcelain may be worn and may effect on masticatory physiology and prosthetic function. The purpose of this experiment was to study on wear of porcelain surface which treated in different method. Using the abrasion device which was designed and constructed by myself, the different porcelain surface were abraded by gold alloy, nickel-chrome alloy and natural teeth in order to compare roughness. Results were as follows. 1. The group of porcelain abraded by gold alloy showed less surface roughness change (t=2.92, p<0.05), and the group of porcelain abraded by natural teeth had high surface roughness. change (t=6.84, p<0.05). 2. According to the method of surface treatment, the surface roughness were very significant (F=9.12, p<0.05). 3. After abrading, the porcelain surface roughness change was very significant (F=54.49, p<0.05). 4. There was no significant between surface treatment method and the kind of abrading materials. (F=1.01, p>0..05). 5. The group of natural glazing had the most smooth surface ($2.1{\pm}1.13{\mu}m$).

• The Journal of Advanced Prosthodontics
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• v.15 no.4
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• pp.202-213
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• 2023

PURPOSE. This prospective clinical study was conducted to evaluate the clinical usefulness of the freely detachable zirconia ball- and spring-retained implant prosthesis (BSRP) through a comparative analysis of screw- and cement-retained implant prosthesis (SCRP). MATERIALS AND METHODS. A multi-center, randomized, prospective clinical study evaluating the clinical usefulness of the detachable zirconia ball- and spring-retained implant prostheses was conducted. Sixty-four implant prostheses in 64 patients were examined. Periodic observational studies were conducted at 0, 3, 6, and 12 months after delivery of the implant prosthesis. Factors such as implant success rate, marginal bone resorption, periodontal pocket depth, plaque and bleeding index, and prosthetic complications were evaluated, respectively. RESULTS. During the 1-year observation period, all implants survived without functional problems and clinical mobility, showing a 100% implant success rate. Marginal bone resorption was significantly higher in the SCRP group than in the BSRP group only at the time of implant prosthesis delivery (P = .043). In all observation periods, periodontal pocket depth was slightly higher in the BSRP group than in the SCRP group, but there was no significant difference (P > .05). The modified plaque index (mPI) scores of both groups were moderate. Higher ratio of a score 2 in modified sulcus bleeding index (mBI) was observed in the BSRP group in the 6- and 12-months observation. CONCLUSION. Within the limitations of this study, the newly developed zirconia ball- and spring-retained implant prosthesis could be considered as an applicable and predictable treatment method along with the existing screw- and cement-retained prosthesis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.2
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• pp.74-77
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• 2015

Objectives: Transpositioning of the inferior alveolar nerve to prevent injury in lower jaw has been advocated for orthognathic, pre-prosthetic and for implant placement procedures. However, the concept of infra-orbital nerve repositioning in cases of mid-face fractures remains unexplored. The infraorbital nerve may be involved in trauma to the zygomatic complex which often results in sensory disturbance of the area innervated by it. Ten patients with infraorbital nerve entrapment were treated in similar way at our maxillofacial surgery centre. Materials and Methods: In this article we are reporting three cases of zygomatico-maxillary complex fracture in which intra-operative repositioning of infra-orbital nerve into the orbital floor was done. This was done to release the nerve from fractured segments and to reduce the postoperative neural complications, to gain better access to fracture site and ease in plate fixation. This procedure also decompresses the nerve which releases it off the soft tissue entrapment caused due to trauma and the organized clot at the fractured site. Results: There was no evidence of sensory disturbance during their three month follow-up in any of the patient. Conclusion: Infraorbital nerve transposition is very effective in preventing paresthesia in patients which fracture line involving the infraorbital nerve.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.1
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• pp.1-7
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• 2019

Purpose: The laser processability of dental prosthesis is investigated using two ceramic composites, including 3M, Lava Ultimate and Ivoclar vivadent, IPS e.max. Materials and methods: The $CO_2$ laser, picosecond laser and femtosecond laser are used to assess the processing power of dental prosthetic materials Lava Ultimate and IPS e.max and the line processing shape was measured using a confocal microscope. Results: The brittleness, carbonization and micro crack of the ceramic composite were influenced by heat accumulation of the material and could be controlled by the laser power and pulse time. Conclusion: In the case of $CO_2$ lasers, micro crack and carbonation occurred immediately, and in the picosecond laser processing, the micro cracks are partially improved, but the carbonization occurs continuously. Finally, we confirmed the high efficiency of laser processing with femtosecond laser. In particular, Lava Ultimate, a ceramic resin composite material, showed the best processability when processed using a femtosecond laser.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.116-126
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• 2018

Purpose: The purpose of this study was to analyze the factors affecting the survival rate and the marginal bone level of dental implants that have functioned over 7-years. Materials and Methods: In 92 patients, 178 dental implants were included. Implant-related factors (diameter, length, prosthetic splint), patient-related factors (gender, smoking, plaque index, compliance to supportive periodontal therapy) and surgery-related factors (proficiency of surgeon, bone graft) were evaluated via clinical and radiographic examination. The marginal bone level was determined by intraoral standard radiography at the mesial and distal aspects of each implant using an image analysis software program. Results: The survival rate of all the implants was 94.94% and the marginal bone level was $0.89{\pm}1.05mm$, these results are consistent with other studies that present long-term good clinical results. Implant length and plaque index among several factors were statistically significant for implant survival rate (P < 0.05). Smoking and the presence of regeneration surgery were statistically significant for the marginal bone level (P < 0.05). Conclusion: Dental implant that have functioned over 7-years showed favorable long-term survival rates and marginal bone level. Implant length and plaque control should be considered for improving the long-term clinical results. It is needed that careful application of bone regeneration technique and smoking control for maintaining of marginal bone level.