• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.311-320
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• 2009

Purpose: The aim of the present study was to analyze 7-year cumulative survival rate (CSR, %) of dental implants in the controlled diabetic patients and to evaluate the influence of the position, diameter and length of fixture, bone quality, age, gender and the method of maxillary sinus elevation on the survival rate. Methods: The data of 342 placed implants in the 104 diabetic patients collected between 1995 and 2007 at the Department of Periodontology in Yonsei University Hospital were analyzed. Results: Seven-year CSR of the 342 dental implants in the 104 controlled diabetic patients was 96.5%. The survival rates of the placed implants according the position have no statistically significant difference. The survival rates according to the length or diameter of the fixtures have no statistically significant difference. The survival rates according to the bone quality were 100% (Type I), 97.1% (Type II), 97.7% (Type III) and 85.7%(Type IV). The difference between the survival rate of Type I, II and III and that of Type IV was statistically significant. The survival rates according to patient gender were 96.8% (male), 95.5% (female). The survival rates according to patient age were 100% (${\leq}59$), 93.8% (${\geq}60$). The survival rates according to the method of sinus elevation in the maxillary posterior area were 96.8% (without sinus elevation), 92.9% (lateral approach) and 89.8% (crestal approach). Conclusions: Dental implants can be used successfully in the controlled diabetic patients. In case of upper posterior region which has poor bone density and older patients, the implant treatment should be more properly planed, executed, and followed-up.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.535-542
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• 2007

Background : Repeated dis/re-connection of implant abutment caused bone loss around implant fixtures due to the new formation of biologic width of the mucosal-implant barrier. The aim of this clinical study was to evaluate whether the repeated dis/re-connection of implant abutment cause bone loss clinically and the effect of cleansing methods on a bone loss during the early healing period. Methods : A total 50 implants were installed in 20 patients and repeated dis/re-connection of abutment was performed at the time of surgery and once per week for 12 weeks. 0.9% normal saline solution as group1 and 0.1% chlorhexidine solution as group 2 was used to clean abutments. All patients had radiographs taken at the placement of implant and 4, 8, and 12 weeks postoperatively. The data for bone loss around implant were analyzed. Results: The marginal bone loss at 12 weeks were $1.28{\pm}0.51mm$, $1,32{\pm}0,57mm$ in the mesial and distal sides in group1, $1.94{\pm}0.75mm$, $1.81{\pm}0.84mm$ in group 2, respectively. In view of marginal bone loss, there was not a significant statistical difference between groups. Conclusions : Repeated dis/re-connection of implant abutment may not cause marginal bone loss around implant fixture although limited samples and short-term observation period. In spite of more bone loss in group 2, there was no statistical significant difference between groups. In context of those results, the clinical significance of the repeated dis/re-connection of implant abutment and the cleansing method of abutments is debatable when it comes to marginal bone loss during early healing period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.3
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• pp.186-199
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• 2012

Purpose: Single implants, of which screw loosening has been observed frequently, presents problems such as fixtures fractures, marginal bone loss, and inflammation of the soft tissue around the implant. However, the single implant is more conservative, cost effective, and predictable compared to the 3 unit bridge with respect to the long-term outcome. This study evaluated the survival rate as well as future methods aimed at increasing the survival rate in single implants in posterior teeth. Methods: Among the implants placed in the Dankook University Dental Hospital department of Oral & Maxillofacial surgery from January 2001 to June 2008, 599 implants placed in the maxillar and mandibular posterior were evaluated retrospectively. Survival rates were investigated according to implant location, cause of tooth loss, gender, age, general disease, fixture diameter and length, surface texture, implant type and shape, presence of bone graft, surgery stage, surgeons, bone quality and opposite teeth. Results: Out of 599 single implants in posterior teeth, 580 implants survived and the survival rate was 96.8%. The difference in survival rate was statistically significant according to the implant location. The survival rate was low (84.2%) in implants exhibiting a wide diameter (${\geq}5.1mm$) and the surface treated by the acid etching group demonstrated a significantly lower survival rate (91.1%). One stage surgical procedure, which implemented a relatively better bone quality survival rate (100%), was higher than the two stage surgical procedure (96.1%). The survival rate of type IV bone quality (75%) was significantly lower than the other bone quality. Conclusion: Single posterior teeth implant treatments should use an improved surface finishing fixture as well as careful and safe procedures when performing implant surgery in the maxilla premolar and molar regions since bone quality is poor.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.529-536
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• 2010

Purpose: The Purpose of this study is to show the total survival rate of implants with maxillary sinus grafting and the effects that reach the survival rate by classifying types of graft materials, implant type, operation method, residual bone height and evaluate graft material resorption rate after sinus grafting Patients and Methods: 61 dental implants placed with sinus bone grafting in 24 patients at Wonkwang University Sanbon Dental Hospital were installed simultaneously or after regular healing. Various bone grafts (autograft, xenograft, allograft, alloplast) and fourth implant type (GSII, Xive, Implantium, Novel biocare) were used. All implants were investigated clinically and radiographically, being with average 20 months follow-up period after installation. Results: 3 fixtures were lost, resulting in 95.1% cumulative survival rate of 61 osseointegrated dental implant. Survival rate according to bone material type, Implant type, operation method, residual bone height, have no statistically significant differencies. The mean preoperative residual alveolar bone height was 4.75 mm, average postoperative height of graft materials 10.8 mm, vertical bone resorption rate was 10% after 2 years. Resorption rate according to operation method was 7% (simultaneous) and 5% (delayed) after 1 year. Conclusion: It can be suggested that maxillary sinus grafting may have predictable result with various bone graft materials and implant type, residual bone height, operation method

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.442-446
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• 2010

Purpose: The purpose of this study was to compare the clinical efficacy of popular bone graft materials mineralized allograft and deproteinized bovine bone mineral. Materials and Methods: One hundred seven implants of 78 patients, accompanied by sinus lift using the lateral window technique and simultaneous implantation, were sampled. In addition, some patients with severe systemic conditions were excluded. The initial bone heights of all patients ranged from 3-6 mm. All of the sample cases were treated at our hospital from January 2005 to January 2008. Techniques other than the lateral window technique were excluded, and only one graft material ($Tutoplast^{(R)}$ or Bio-$Oss^{(R)}$) was accepted for inclusion. $Tutoplast^{(R)}$ was used in 63 implants of 41 patients, whereas Bio-$Oss^{(R)}$) was chosen for the remaining 44 implants of 37 patients. The diameters of the particles used ranged from 0.25-1.0 mm, and the volume was 0.5-2 cc (mean, 1.5 cc). Results: The survival rate of the implant fixtures was 99.07% when the lateral window technique was used. Among all of the cases, cases in which $Tutoplast^{(R)}$ was used demonstrated a survival rate of 98.4%, whereas Bio-$Oss^{(R)}$) resulted in 100% survival. With respect to the alveolar bone height, no significant differences were detected between the two graft materials that failed. Conclusion: According to the result reported above, the two common materials for sinus augmentation do not have clinically significant difference. Rather, host factors, such as the height of residual bone, which could be disclosed during questioning patients' systemic conditions, might have greater effects on the prognosis.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.617-625
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• 2003

Statement of problem : There are many studies focused on the effect of shape of futures on stress distribution in the mandibular bone. However, there are no studies focused on the effect of the abutment types on stress distribution in mandibular bone. Purpose : The purpose of this study is to investigate the effect of three different abutment types on the stress distributions in the mandibular bone due to various loads by performing finite element analysis. Material and method : Three different implant systems produced by Warantec (Seoul, Korea), were modeled to study the effect of abutment types on the stress distribution in the mandibular bone. The three implant systems are classified into oneplant (Oneplant, OP-TH-S11.5). internal implant (Inplant, IO-S11.5) and external implant (Hexplant, EH-S11.5). All abutments were made of titanium grade ELI. and all fixtures were made of titanium grade IV. The mandibular bone used in this study is constituted of compact and spongeous bone assumed to be homogeneous, isotropic and linearly elastic. A comparative study of stress distributions in the mandibular bone with three different types of abutment was conducted. Results : It was found that the types of abutments have significant influence on the stress distribution in the mandibular bone. It was due to difference in the load transfer mechanism and the size of contact area between abutment and fixture. Also the maximum effective stress in the mandibular bone was increased with the increase of inclination angle of load. Conclusion : It was concluded that the maximum effective stress in the bone by the internal implant was the lowest among the maximum effective stresses by other two types.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.669-678
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• 2008

Purpose: The purpose of this study was to evaluate 2 years cumulative survival rate of implants on augmented sinus area using MBCP, mixture of MBCP and ICB, and mixture of MBCP and autogenous bone by means of clinical and radiologic methods. Materials and Methods: In a total of 37 patients, 41 maxillary sinuses were augmented and 89 implant fixtures were installed simultaneously or after a regular healing period. The patients were divided in 3 groups: MBCP only, MBCP combined with ICB, MBCP combined with autogenous bone. After delivery of prosthesis, along 2 years of observation period, all implants were evaluated clinically and radiologically. And the results were as follows. Results: The results of this study were as follows. 1. A 2 year cumulative survival rate of implants placed with sinus augmentation procedure using MBCP was 97.75%. 2. Survival rate of implants using MBCP only was 97.62%, MBCP and ICB was 100%, MBCP and autogenous bone was 95%. There was no statistically significant difference between 3 groups. 3. Only 2 of 89 implants were lost before delivery of prosthesis, so it can be regarded as an early failure. And both were successfully restored by wider implants. Conclusion: It can be suggested that MBCP may have predictable result when used as a grafting material of sinus floor augmentation whether combined with other graft(ICB, autogenous bone) or not. And the diameter, length, location of implants did not have a significant effect on 2 year cumulative survival rate.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.31-42
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• 2007

The purpose of this study was to compare the stress distribution according to the splinting condition and non-splinting conditions on the finite element models of the two units implant prostheses. The finite element model was designed with the parallel placement of two fixtures ($4.0mm{\times}11.5mm$) on the mandibular 1st and 2nd molars. A cemented abutment and gold screw were used for superstructures. A FEA models assumed a state of optimal osseointegration, as the bone quality, inner cancellous bone and outer 2 mm compact bone was designed. This concluded that the cortical and trabecular bone were assumed to be perfectly bonded to the implant. Splinting condition had 2 mm contact surface and non-splinting condition had $8{\mu}m$ gap between two implant prosthesis. Two group (Splinting and non-splinting) were loaded with 200 N magnitude in vertical axis direction and were divided with subdivision group. Subdivision group was composed of three loading point; Center of central fossa, the 2 mm and 4 mm buccal offset point from the central fossa. Von Mises stress value were recorded and compared in the fixture-bone interface and bucco-lingual sections. The results were as follows; 1. In the vertical loading condition of central fossa, splinting condition had shown a different von Mises stress pattern compared to the non-splinting condition, while the maximum von Mises stress was similar. 2. Stresses around abutment screw were more concentrated in the splinting condition than the non-splinting condition. As the distance from central fossa increased, the stress concentration increased around abutment screw. 3. The magnitude of the stress in the cortical bone, fixture, abutment and gold screw were greater with the 4 mm buccal offset loading of the vertical axis than with the central loading.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.98-104
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• 2011

Purpose: The aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmentedsinus using Osteon, a bone graft material, and to assess the height of the grafted material through radiographic evaluation. Methods: Twenty patients were treated with maxillary sinus augmentation and 45 implant fixtures were installed simultaneously or after 6 months healing period. The height of the augmented sinus and the loss of marginal bone were measured by panoramic and intraoral radiographs immediately after augmentation and up to 42 months (mean, 19.4 months) subsequently. Changes in the height of the sinus graft material were calculated radiographically. Results: The cumulative survival rate was 95.56% in all 45 implants. Additionall, normal healing process without any complication was observed in all patients. The original sinus height was mean 4.3 mm and the augmented sinus height was mean 13.4 mm after the surgery. The mean marginal bone loss till 42 months was $0.52{\pm}0.56\;mm$. The reduced height of Osteon was $0.83{\pm}0.38\;mm$ and it did not show significant correlation with the follow up periods (P=0.102). There were no statistically significant differences in reduced height of Osteon according to the simultaneous/delayed implantation (P=0.299) and particle size of Osteon (P=0.644). Conclusions: It can be suggested that Osteon may have predictable result when it was used as a grafting material for sinus floor augmentation.

• Journal of The Korea Institute of Healthcare Architecture
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• v.20 no.4
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• pp.7-16
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• 2014

Purpose : The purpose of this study was to examine the nurses' needs for the spatial composition of geriatric hospital. Methods : The survey method was used for collecting the data. The subjects were 110 nurses who worked at 6 geriatric hospitals in Busan. They answered the questionnaire by the self-administered method. The questionnaire consisted of items which asked the spatial composition of patient room, bathroom, dining space, resting space, care-givers' room, and garden. Results : 1) The patient room using a bed on ondol floor would be useful. Also, it would be desirable that most patient rooms consisted of 4 or 6 persons per patient room and the others were 1 or 2 persons per room. 2) The bathroom for only patients and the shower room for their families or care-givers are needed in the geriatric hospital. 3) The dining room for patients in each floor would be useful to old patients. In addition to that, the cafeteria for their families or care-givers are needed. 4) The resting space for patients and their families, for the staff, and for care-givers are needed. 5) The personal locker and refrigerator are necessary fixtures in care-givers' room. Also, table, sofa, sink, and shower booth are also needed. 6) On the base of activities of care-givers, the space for preserving, washing, and heating foods are needed. Also, the storage space for personal items and the fitting space are needed. Implications : The results of this study would be the fundamental data for space planning of the geriatric hospital.