• 대한구강악안면임플란트학회지
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• 제22권4호
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• pp.220-235
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• 2018

Sinus lift procedure is frequently required for the maxillary molar implant placement. Previous studies have demonstrated alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. However, there is a lack of studies which evaluated the effect of ARP to avoid sinus lift procedure. Purpose of this study is to describe a method reducing the need of sinus lift surgery by ARP in maxillary molar areas and to assess the feasibility clinically, radiologically and histologically. Ten maxillary molars in ten patients had severe vertical bone resorption with minimal residual bone height. They were considered having the high possibility of the necessity of sinus lift procedure for dental implant after the extraction. After extraction, open healing ARP with deproteinized bovine bone mineral mixed with 10% collagen and resorbable collagen membranes was performed. After sufficient healing, dental implants were placed, and evaluated clinically and radiologically. Histological observation was conducted just before the implantation in one patient. Implants were successfully placed without sinus lift in all ten cases. All the implants were restored with no sign of complications, and patients are now in a close follow-up up to 20 months post-loading. Histological observation showed minimal inflammatory reaction and newly formed bone was substantially noted. The ARP technique has successfully avoided the sinus lift surgeries. It appears that this procedure may improve the simplicity of the clinical process for the clinicians and reduce the discomfort of patients.

• The Journal of Advanced Prosthodontics
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• 제14권4호
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• pp.203-211
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• 2022

PURPOSE. The aim of this study was to introduce rating criteria to evaluate student performance in a newly developed, digital wax-up preclinical program for computer-aided design (CAD) of full-coverage crowns and preliminarily investigate the reliability and internal consistency of the rating system. MATERIALS AND METHODS. This study, conducted in 2017, enrolled 47 fifth-year dental students of Okayama University Dental School. Digital wax-up training included a fundamental practice using computer graphics (CG), multipurpose CAD software programs, and an advanced practice to execute a digital wax-up of the right mandibular second molar (#47). Each student's digital wax-up work (stereolithography data) was evaluated by two instructors using seven qualitative criteria. The total qualitative score (0-90) of the criteria was calculated. The total volumetric discrepancy between each student's digital wax-up work and a reference prepared by an instructor was automatically measured by the CAD software. The inter-rater reliability of each criterion was analyzed using a weighted kappa index. The relationship between the total volume discrepancy and the total qualitative score was analyzed using Spearman's correlation. RESULTS. The weighted kappa values for the seven qualitative criteria ranged from 0.62 - 0.93. The total qualitative score and the total volumetric discrepancy were negatively correlated (ρ = -0.27, P = .09, respectively); however, this was not statistically significant. CONCLUSION. The established qualitative criteria to evaluate students' work showed sufficiently high inter-rater reliability; however, the digitally measured volumetric discrepancy could not sufficiently predict the total qualitative score.

• 대한치과의료관리학회지
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• 제8권1호
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• pp.37-40
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• 2020

The background of this study is the observation that there is an increase in the number of elderly persons and the decrease in fertility rates, which may be related to the increase in the average age of the Korean people; accordingly, the national health insurance system changes every year following this pattern. However, this study investigates whether these changes are reflected in the dental hygiene curriculum. Data from the national health insurance system is reviewed for the last three years, and the recently published dental hygiene curriculum is selected, compared, and analyzed using a literature survey. The study is divided into two parts: information that is reflected in the dental hygiene curriculum and information that is not reflected in the dental hygiene curriculum, but which it is believed should be included. In addition, as the part reflected in the dental hygiene curriculum, it was stated in three subjects of dental implantology, dental prosthesis, and conservative dentistry, and there were four cases. Therefore, efforts should be made to ensure that the curriculum for dental hygiene students should reflect the changes in the national health insurance system so that students can more easily understand dental insurance claim processes.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권2호
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• pp.103-111
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• 2011

Purpose: Choukroun's platelet-rich-fibrin (PRF) is composed of platelets, white blood cells and fibrin matrix. It does not induce enough bone formation by itself but it can improve bone formation with calcium. Silk fibroin does not cause inflammatory reactions because it is bio-compatible and degradable. The purpose of this study was to exam the bone formation when a combination of Choukroun's PRF and silk fibroin was used. Methods: In this study, cell reactions to silk powder with differing molecular weights was first tested to select the appropriate silk powder. Then we applied these bone graft materials on defects of skull and in a peri-implant bony defect model in New Zealand rabbits. The results between the experimental and control s (non-grafted) group were analyzed. Results: The small sized silk fibroin powder showed increased cellular proliferation for bone-regeneration. There was no statistically significant difference between the experimental group and the control group at 6 weeks, but more new bone formation was observed in the combination graft group at 12 weeks (P<0.05). And in the dental implant model, the combination bone graft group showed much improved torque test results, which was statistically significant. Histomorphometric analysis showed more regenerated cortical bone and a higher mean bone to implant in the experimental group. Both were statistically significant. Conclusion: The combination graft of Choukroun's platelet-rich-fibrin (PRF) and silk fibroin powder can successfully restore the bony defects in a skull defected model and a peri-implant bony defects model.

• 대한치과의사협회지
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• 제48권1호
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• pp.27-37
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• 2010

Current trend of aging society suggests that many patients are at risk for various preoperative preparations and postoperative complications during and following invasive dental procedures, due to an acquired medically compromised conditions from systemic disease and/or from medications. The medical history is critical for the identification of patients potentially at risk for medically compromised and old aged patients' factors from dental treatment. The proper dental management requires an understanding of certain principles of pathophysiology for these medical conditions and some standard laboratory tests. Polypharmacy in old age, besides representing a risk in and of itself, points to the potential risk the underlying diseases that necessitated the drugs can present in the dental office. These diseases and medications can also present a risk to oral health. A sequence for categorizing drugs in a medication list is presented here to aid in the identification of potential risks in the dental treatment and management of patients with complex medical histories and drug regimens. Specific patient populations, such as pediatric, may have specific drugs or additional criteria that need to be considered. Practitioners must use the health history and the medication list in concert, using one to make sense of the other and utilizing all the information available from reviewing each one carefully in order to manage their increasingly complex patients safely and effectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권5호
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• pp.340-345
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• 2009

Purpose: The purpose of this study was to evaluate the surgical success of bone reconstruction of the severely atrophic maxilla using autogenous block bone onlay graft from the ramus and ilium prior to dental implantation. And we measured the amount of vertical height change Material and Methods: 26 partially edentulous patients(32 case) who needed block onlay bone graft before implant placement in posterior maxillary area from 2002 to 2009 were selected for this study. Patients consisted of 20 males & 6 females and the average of their age was 54.2. Patients who were treated with ramal bone were 19 case and patients who were treated with iliac bone were 11 case. Digital panoramic X-ray was taken at the day of surgery, 3 months and 6 months later after the surgery. Vertical height change & resorption rate of grafted bone were measured with the same X-rays and compared Results: Two out of 32 bone grafts had to be removed because of inflamation at the grafts area(97.3%). The mean of radiographic vertical height change(change rate) of post-op. 3 month was 0.54mm(8.5%)and 6 month was 0.99mm(15.9%). Compairing to intraoral donor site(ramus), iliac bone had more vertical height change(1.18mm) at 6 month after surgery. Conclusions: Within the limit of this study, autogenous block onlay grafts can be considered a promising treatment for severely atrophic maxilla.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권3호
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• pp.170-175
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• 2009

Purpose : The purpose of this study is to evaluate 7-year survival rate of implants placed without bone graft in posterior maxilla and compare the survival rate by the age and gender of patient, length and diameter of implant, region of implant placement, bicortical engagement of fixture, and connection of prosthesis. Material and methods : 78 patients (170 implants) who visited our institution from 2002 to 2007 and were followed up with panoramic view and medical records. Kaplan-Meier survival analysis and Log Rank (Mantel-Cox) test were used. Results and conclusions : A 7-year cumulative survival rate for implants placed in posterior maxilla without sinus graft was 95.3%. The survival rate in men was 91.8%, significantly lower than 98.8% in woman.(p<0.05). However, the survival rate by the length of the implants did not show any significant differences.(p>0.05), while the wide platform implant resulted in 85% survival rate which was statistically lower than 98.5% in regular platform. The posterior maxillary implants engaged bicortically showed 97.6% of 7-year Survival rate, comparing 88.6% in not engaged implants. The survival rate of the single implant was 91.2%, while 98.5% in splinted prosthesis. Therefore, the bicortical engagement of the fixtures and splinted prosthesis may be recommended to get a long-term survival rate in posterior maxilla.

• 대한치과의사협회지
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• 제53권1호
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• pp.6-13
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• 2015

A new field in dental implantology is developing with the goal of finding new ways to improve the osteoconductivity of bone substitutes and to study new molecules able to dictate cellular differentiation and improve bone regeneration. The real future in bone regeneration seems to be in connection with the rhBMP-2s, currently obtained by synthesis using recombinant DNA. Since the first rhBMP-2 studies in humans by Boyne, There are many studies for bone regeneration at oral and maxillofacial area. The rhBMP-2 is widely used at sinus augmentation, alveolar bone defect, and socket preservation.

• 대한치과보철학회지
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• 제34권4호
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• pp.675-686
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• 1996

Today, dental implants are an acceptable alternative, capable of providing bone-anchored fixed prostheses for improved quality of life and self esteem for many patients. Research advances in dental implantology have led to the development of several different types of materials, and it is anticipated that continued research will likewise lead to advanced dental implant materials. Currently used pure titanium has relatively low hardness and strength which possibly limits its ability to resist the functional loads as a dental implant. Ti-6Al-4V also has potential problems such as corrosion resistance, bone biocompatibility etc. The carefully selected Zr, Nb, Ta, Pd, In constituents could improve mechanical strength, corrosion resistance, and biocompatibility compared to that of currently used implant metals. On the basis of the totality of the data from our study, it can be concluded that new titanium alloys containing Zr, Nb, Ta, Pd, In are able to provide improved mechanical properties, corrosion resistance and biocompatibility to warrant further investigation of it's potential as new biomaterials for dental implants.

• 대한치과보철학회지
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• 제53권1호
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• pp.74-80
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• 2015

구강암의 발생 시, 구순의 결손과 방사선치료에 의한 치주조직과 치경부우식증 등의 문제가 발생할 수 있다. ADI (Association of dental implantology)에 의하면 상 하악골에 대한 방사선치료가 최근에 시행되었을 경우 임플란트를 식립하는 것은 상대적 비적응증이 된다. 대부분의 경우 임플란트를 이용한 보철물의 제작이 어렵고 의치를 사용한 수복이 이루어지게 된다. 특히, 구강암 수술로 인한 구순결손은 의치의 유지에 심각한 영향을 주게 된다. 본 증례는 상순암을 가진 환자로 일차적으로 절제술을 시행하고, 이차적으로 방사선 치료가 정기적으로 이루어진 결과, 환자의 상악 치아들은 순차적으로 자연 발치되었고, 하악은 매우 불량한 치주상태를 나타내었다. 상악은 총의치에 의치접착제를 적용하여 구순결손에 의한 의치의 유지력 저하를 극복하였고, 하악에서는friction pin을 이용한 하악이중관의치가 2년 동안 성공적으로 사용되었다.