• 대한치과보철학회지
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• 제43권5호
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• pp.662-670
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• 2005

Statement of problem: Little is known about the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Purpose: This study evaluated the effect of abutment preparation procedure on do-torque values in different implant platform and the relationship of final do-torque values with different implant platform size. Material and method: Six ITI implants (2 narrow-neck implants, 2 regular-neck implants, 2 wide-neck implants) and six Branemark implants (2 narrow platforms, 2 regular platforms, 2 wide platforms) were embedded in each acrylic resin block with epoxy resin. Eighteen $synOcta^(R)$ abutments (6 narrow-neck implant-abutments, 6 regular-neck implant-abutments, 6 wide-neck implant-abutments) and eighteen esthetic abutments (6 narrow platform-abutments, 6 regular platform-abutments, 6 wide platform-abutments) were tightened to each implant with digital torque gauge. Initial do-torque values were measured using digital torque gauge. After preparation of abutments, Final do-torque values were measured with digital torque gauge. Results and conclusion: 1. Screws loosening or abutments motion were not detected in all experimental group, but some scratches of implant-abutment joints were detected in all group 2. Reduction ratios of final do-torque values were greater than initial do-torque values in all measured group, except in narrow-neck implant-abutment group (p<0.05). 3. Reduction ratios of final do-torque values in wide-neck implant-abutment group were greater than regular-neck implant-abutment group (p<0.01). 4. The greatest standard deviation value was detected in wide platform group in both implant systems.

• 대한치과보철학회지
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• 제47권1호
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• pp.70-81
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• 2009

연구목적: 캔틸레버의 위치와 길이는 임플란트와 보철물 또한 주위 골조직의 응력분포에 중요한 영향을 미친다. 하악 무치악의 경우 기존에는 양측 이공사이에 4-6개의 임플란트를 식립하고 상부보철물을 캔틸레버형으로 제작해왔는데 캔틸레버 부위에 무리한 하중이 작용하게 되면 응력의 집중과 굽힘 현상으로 인하여 최후방 임플란트 부위의 지지골 파괴와 임플란트 및 상부 보철물의 파절을 초래했다. 이러한 캔틸레버의 약점을 보완하기 위해 1992년 McCartney가 Rest implant 개념을 2003년에는 $Mal{\acute{o}}$ 등이 All-on-Four implant 개념을 소개하여 기존 보철물의 캔틸레버 길이를 줄이려고 노력하였다. 재료 및 방법: 기존의 캔틸레버형 보철물과 rest implant, All-on-Four implant 시스템을 삼차원 모델링하여 하중을 제 1대구치 부위에 수직으로 300 N, 수평으로 설측에서 협측으로 75 N을 가하여 지지골과 임플란트, 상부보철물에 발생하는 응력의 크기와 분포 및 분산양상을 유한요소 해석 프로그램인 ANSYS (Ver. 10.0, Swanson Analysis System Inc., USA)를 이용하여 분석하였다. 결과: 1. 레스트 임플란트 및 All-on-Four 임플란트법은 기존 방법에 비해 하악골과 상부 보철물의 응력 분산에 크게 영향을 미치는 것으로 나타났다. 2. 지지골, 임플란트, 상부 보철물에서의 응력분산은 레스트 임플란트가 가장 우수한 것으로 나타났다. 3. 같은 개수의 임플란트인 경우 후방 임플란트를 경사시켜 캔틸레버의 양을 줄이는 것이 기존 방식에 비해 저작압 분산에 유리하다.

• The Journal of Advanced Prosthodontics
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• 제6권4호
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• pp.245-252
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• 2014

PURPOSE. To present a literature review on implant overdentures after a brief survey of bone loss after extraction of all teeth. MATERIALS AND METHODS. Papers on alveolar bone loss and implant overdentures have been studied for a narrative review. RESULTS. Bone loss of the alveolar process after tooth extraction occurs with great individual variation, impossible to predict at the time of extraction. The simplest way to prevent bone loss is to avoid extraction of all teeth. To keep a few teeth and use them or their roots for a tooth or root-supported overdenture substantially reduces bone loss. Jaws with implant-supported prostheses show less bone loss than jaws with conventional dentures. Mandibular 2-implant overdentures provide patients with better outcomes than do conventional dentures, regarding satisfaction, chewing ability and oral-health-related quality of life. There is no strong evidence for the superiority of one overdenture retention-system over the others regarding patient satisfaction, survival, peri-implant bone loss and relevant clinical factors. Mandibular single midline implant overdentures have shown promising results but long-term results are not yet available. For a maxillary overdenture 4 to 6 implants splinted with a bar provide high survival both for implants and overdenture. CONCLUSION. In edentulous mandibles, 2-implant overdentures provide excellent long-term success and survival, including patient satisfaction and improved oral functions. To further reduce the costs a single midline implant overdenture can be a promising option. In the maxilla, overdentures supported on 4 to 6 implants splinted with a bar have demonstrated good functional results.

• 대한치과보철학회지
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• 제59권4호
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• pp.497-507
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• 2021

무치악 환자에서 잔존 치조골을 최대의 효율로 활용해 임플란트 고정성 보철물을 수복하는 치료법 중 하나로 All-on-6 개념을 사용할 수 있으나, 치료과정에서 복잡함과 번거로움이 동반된다. 나날이 발전해 온 디지털 시스템을 활용한다면 무치악 환자의 임플란트 식립부터 보철물 제작 및 수복까지 높은 효용성으로 활용할 수 있다. 본 증례에서는 76세 상악 무치악 환자의 일체형 나사 유지형 고정성 임플란트 보철 수복(1-piece design, screw retained implant fixed prosthesis)에 대해 진단부터 임플란트 식립 그리고 보철물 제작까지 전 과정에서 디지털 시스템을 활용하였다. 술전 진단에서 구강직접스캔(Direct intraoral scan)을 통해 환자의 정보를 데이터화 하였으며 이를 토대로 임플란트 식립 수술 가이드와 식립직후 장착할 즉시 임시보철물을 디자인 하였다. 최적의 잔존 치조골 위치에 식립된 6개의 임플란트 위치정보에 따라 정밀하게 제작된 즉시 임시보철물을 수복하여 술 후 사용 가능하도록 하여 환자의 불편감을 최소화하였다. 디지털 시스템을 활용하여 환자의 요구사항, 안정된 수직고경과 교합, 심미성을 고려하여 제작한 새로운 임시보철물을 거쳐 최종보철물을 디자인하고 제작하였다. 디지털 시스템을 활용하여 무치악 환자의 효율적이고 정확한 임플란트 식립부터 보철물 제작까지 전 과정에 있어서 복잡한 임플란트 치료과정을 단순화하여 환자의 불편감을 최소화시키고 기능적이고 심미적인 결과를 얻어 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.21.1-21.6
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• 2017

Background: The purposes of the present study were to compare implant stabilities of mandibular block bone graft and bovine bone graft and to evaluate influencing factors for implant stability in mandibular block bone (MBB) graft. Methods: This retrospective study investigated 1224 cases and 389 patients treated by one surgeon in the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital (Yangsan, Korea) between January 2010 and December 2014. Proportions that MBB graft cases constitute in all implant restoration cases and in all bone graft cases were measured. Implant stability quotient (ISQ) values were achieved by the same surgeon before loading. The average ISQ values of the experimental groups were compared. In addition, ISQ values of influencing factors, such as age, sex, implant size, and implant placement site, were compared within the MBB group using $Osstell^{TM}$ Mentor ($Osstell^{(R)}$, $G{\ddot{o}}teborg$, Sweden). Paired t test and ANOVA were conducted for statistical analysis with a significance level of 0.05. Results: Fifty-five percent of all implant restoration cases performed bone graft while MBB cases constituted 34% of all implant restoration cases and 61% of all bone graft cases. Comparing ISQ values according to bone graft materials, the MBB group manifested sufficient implant stability by presenting comparable ISQ value to that of the experimental group without bone graft. Among the reviewed factors, females, mandibular molar regions, and implants in larger diameter displayed greater implant stabilities. Conclusions: Satisfactory implant stability was accomplished upon administration of MBB graft. Within the limitation of this study, gender, implant site, and implant diameter were speculated to influence on implant stability in MBB graft.

• The Journal of Advanced Prosthodontics
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• 제15권6호
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• pp.290-301
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• 2023

PURPOSE. The study aimed to determine the influence of implant angulation on the trueness of multi-unit implant impressions taken through different techniques and strategies. MATERIALS AND METHODS. As reference models, three partially edentulous mandibular models (Model 1: No angulation; Model 2: No angulation for #33, 15-degree distal angulation for #35 and #37; Model 3: No angulation for #33, 25-degree distal angulation for #35 and #37) were created by modifying the angulations of implant analogues. Using a lab scanner, these reference models were scanned. The obtained data were preserved and utilized as virtual references. Three intraoral scanning (IOS) strategies: IOS-Omnicam, ISO-Quadrant, and IOS-Consecutive, as well as two traaditional techniques: splinted open tray (OT) and closed tray (CT), were used to create impressions from each reference model. The best-fit alignment approach was used to sequentially superimpose the reference and test scan data. Computations and statistical analysis of angular (AD), linear (LD), and 3D deviations (RMS) were performed. RESULTS. Model type, impression technique, as well as interaction factor, all demonstrated a significant influence on AD and LD values for all implant locations (P < .05). The Model 1 and SOT techniques displayed the lowest mean AD and LD values across all implant locations. When considering interaction factors, CT-Model 3 and SOT-Model 1 exhibited the highest and lowest mean AD and LD values, respectively. Model type, impression technique, and interaction factor all revealed significant effects on RMS values (P ≤ .001). CT-Model 3 and SOT-Model 1 presented the highest and lowest mean RMS values, respectively. CONCLUSION. Splinted-OT and IOS-Omnicam are recommended for multi-unit implant impressions to enhance trueness, potentially benefiting subsequent manufacturing stages.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권6호
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• pp.317-321
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• 2015

Objectives: The purpose of this study is to evaluate five-year radiographic follow-up results of the Korean sandblasting with large grit, and acid etching (SLA)-treated implant system. Materials and Methods: The subjects of the study are 54 patients who have been followed-up to date, of the patients who underwent implant surgery from May 1, 2009 to April 30, 2011. In all, 176 implant placements were performed. Radiographs were taken before the first surgery, immediately after the first and second surgeries, immediately and six months after the final prosthesis installation, and every year after that. Bone loss was evaluated by the method suggested by Romanos and Nentwig. Results: A total of 176 implant placements were performed - 122 in men and 54 in women. These patients have been followed-up for an average of 4.9 years. In terms of prosthetic appliances, there were 156 bridges and 20 single prostheses. Nine implants installed in the maxillary molar area, three in the mandibular molar area and two in the maxillary premolar area were included in group M, with bone loss less than 2 mm at the crestal aspect of the implant. Of these, eight implants were single prostheses. In all, six implants failed - four in the mandible and two in the maxilla. All of these failures occurred in single-implant cases. The implant survival rate was 98.1% on the maxilla and 94.3% on the mandible, with an overall survival of 96.6%. Conclusion: Within the limitations of this study, implants with the SLA surface have a very superior survival rate in relatively poor bone environments such as the maxilla.

• Journal of Periodontal and Implant Science
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• 제53권2호
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• pp.145-156
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• 2023

Purpose: The significance of keratinized tissue for peri-implant health has been emphasized. However, there is an absence of clinical evidence for the use of a xenogeneic collagen matrix (XCM) to manage peri-implant mucositis and peri-implantitis. Therefore, the purpose of this study was to investigate outcomes after keratinized tissue augmentation using an XCM for the management of peri-implant diseases. Methods: Twelve implants (5 with peri-implant mucositis and 7 with peri-implantitis) in 10 patients were included in this study. Non-surgical treatments were first performed, but inflammation persisted in all implant sites. The implant sites all showed a lack of keratinized mucosa (KM) and vestibular depth (VD). Apically positioned flaps with XCM application were performed. Bone augmentation was simultaneously performed on peri-implantitis sites with an intrabony defect (>3 mm). The following clinical parameters were measured: the probing pocket depth (PPD), modified sulcular bleeding index (mSBI), suppuration (SUP), keratinized mucosal height (KMH), and VD. Results: There were no adverse healing events during the follow-up visits (18±4.6 months). The final KMHs and VDs were 4.34±0.86 mm and 8.0±4.05 mm, respectively, for the sites with peri-implant mucositis and 3.29±0.86 mm and 6.5±1.91 mm, respectively, for the sites with peri-implantitis. Additionally, the PPD and mSBI significantly decreased, and none of the implants presented with SUP. Conclusions: Keratinized tissue augmentation using an XCM for sites with peri-implant mucositis and peri-implantitis was effective for increasing the KMH and VD and decreasing peri-implant inflammation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권4호
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• pp.383-394
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• 1997

This study was done to examine adherence of oral bacteria to titanium dental implant and to know the effective prophylactic antibiotics using an in vivo model. Three samples each of the implant material were set in an acrylic resin flange and placed in the maxillary buccal sulcus of twenty volunteers. At 6- and 54-hour intervals, each sample was placed on blood agar plate (BAP) and chocolate agar, and then they were incubated and identified. Also antibiotic susceptibility test was performed. The results obtained mere as follows ; 1. The microorganisms were chain-like Gram positive cocci and staphyline Gram positive cocci, Gram positive bacilli in order of frequency were found at 6-hour and 54-hour samples by Gram staining. 2. Streptococci was found predominantly at both 6-hour and 54-hour samples, but number of streptococci was decreased as compared to 6-hour samples. 3. There was no difference in the bacterial species adherent to implant between 6-hour and 54-hour samples. 4. All the microbes were sensitive to AMC (amoxacillin clavulanic acid), chloramphenicol, quinolone and vancomycin in the antibiotic susceptibility test. Above results suggest that streptococcus are mainly adhered to titanium implant after implant was placed in the oral cavity and AMC is the most recommendable antibiotics to prevent the peri-implant inflammation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.325-340
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• 2008

The purpose of this study was to evaluate the artificial dental plaque by Streptococcus mutans on 4 different implant surfaces. In this study, the specimens were divided into 4 groups according to implant surface treatment. Uncoated implant group(n=5) which has an uncoated, smooth surfaced implant(Osstem, Korea), SLA implant group(n=5) which has an sandblasted large grit and acid-etched surface implant(Bicon, USA). Oxidized implant group(n=5) which has an oxidized surfaced implant (Osstem, Korea), and RBM implant group(n=5) which has resorbable blasting media(RBM) surfaced implant(Osstem, Korea). Acquired pellicle by human saliva and dental plaque by Streptococcus mutans were made on each implant surface. To analyze the plaque condition on implants surfaces, cell count and optical density were taken as a microbiologic method, and SEM(Scanning Electronic Microscope) findings was also taken for evaluation of surface condition. The following results were obtained. 1. Cell counting results of artificial dental plaque were Uncoated group($658.0{\pm}102.0$), RBM group($878.0{\pm}170.0$), SLA group ($946.0{\pm}42.0$), Oxidized group($992.0{\pm}40.0$), and there was difference between Oxidized group and Uncoated implant group(p<0.05). In case of modified cell counting results by v/w% were RBM group($197.8{\pm}45.2$), Oxidized group($207.04{\pm}8.34$), Uncoated group($261.6{\pm}40.6$), SLA group($315.4{\pm}14.0$), and there was difference between RBM group and SLA group(p<0.05). 2. Optical density results of artificial dental plaque after ultrasonic treatment was that there was difference among groups, and optical density of RBM group was higher than that of Uncoated group(p<0.05). In case of modified optical density results by v/w%, there was difference among groups, and the modified optical density of Uncoated group and SLA group was higher than those of Oxidized group and RBM group(P>0.05). 3. SEM findings of artificial dental plaque on the surfaces of implant as follows; there were artificial dental plaque on the surfaces of all test implants. Streptococcus mutans and by-product were observed at 10,000 times magnified condition on all test implants. Adhesion area of artificial dental plaque was about 1/2 of total surface after 24 hours incubate at $37^{\circ}C$. These results showed that there were differences among implant surfaces on the growth of Streptococcus mutans, and bacteria and by-product were covered about 1/2 area of total implant surfaces at 24 hours incubate at $37^{\circ}C$.