• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.25 no.1
• /
• pp.15-24
• /
• 2016

It is considered an implant failure when there is esthetic problems in the anterior area although the prosthesis function normally. In 2003, Dr. Kan et al stated that implant bone level is determined by the adjacent teeth. After that many scholars have studied how can achieve the esthetics result on adjacent teeth bone loss cases. In 2012, Dr. Takino published an article in Quintessence. He summarized previous articles and reclassified the defects from class 1 through 4. Class 1 and 2 depicts a situation where there is no bone loss on adjacent teeth. In Class 3 and 4, interproximal bone loss extends to the adjacent tooth. If one side is involved, it is Class 3. If both sides are involved, it is Class 4. The clue for esthetic implant restoration is whether bone loss extends to adjacent tooth or not. If the bone level of adjacent tooth is sound, we can easily achieve the esthetic but the bone level is not sound, the surgery will be complicated and the esthetic result will be unpredictable. So regenerative surgery for adjacent tooth is necessary for long-term maintenance. But the options and process were so complicated, the purpose of this article is to report the method simplify the surgery and gain a similar outcome.

• Journal of the Korean Orthopaedic Association
• /
• v.54 no.2
• /
• pp.100-109
• /
• 2019

The rapidly increasing rate of shoulder arthroplasty is certain to increase the number of revision arthroplasties because of parallel increases in complication numbers. It has been widely reported that the causes of revision shoulder arthroplasty include rotator cuff deficiency, instability, glenoid or humeral component loosening, implant failure, periprosthetic fracture, and infection. Revision arthroplasty can be technically challenging, and surgical options available for failed shoulder arthroplasty are limited, especially in patients with glenoid bone loss or an irreparable rotator cuff tear. Furthermore, the outcomes of revision arthroplasty are consistently inferior to those of primary arthroplasty. Accordingly, surgical decision making requires a good understanding of the etiology of failure. Here, we provide a review of indications of revision arthroplasty and of the surgical techniques used by failure etiology.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.32 no.1
• /
• pp.16-22
• /
• 2023

Esthetic factors are very important in the success of maxillary anterior implant restoration. However, achieving esthetic results is difficult, especially in cases where periodontitis has resulted in severe alveolar bone loss. In the case of maxillary anterior teeth, the alveolar ridge resorption that begins immediately after tooth extraction interferes with the esthetic implant restoration. Therefore immediate implant placement can be performed to minimize the alveolar ridge resorption. However, in severe bone loss cases, immediate implant placement could result in esthetic failure, and this result might cause irreparable problems. We can also perform alveolar ridge preservation and then place implants later. On JCP published in 2019, there is the consensus of European academy of periodontology on the extraction socket management and the timing of implant placement. This consensus states that alveolar ridge preservation should be considered when there is severe labial bone loss in an esthetically important area such as maxillary anterior region. On performing the alveolar ridge preservation, we cannot obtain the primary wound closure, so secondary wound healing is induced with open membrane technique or soft tissue grafting should be performed for primary wound closure. However, the secondary wound healing can have a negative impact on bone regeneration, and soft tissue grafting such as FGG or CT graft can be burdensome for both patients and dentists. On the other hand, by using the granulation tissue in the extraction socket, primary closure can be achieved without soft tissue grafting. Also some studies have shown that granulation tissue in periodontal defects contains stem cells that may help in tissue regeneration. Based on this, implant restorations were performed on maxillary anterior teeth with severe alveolar bone loss by alveolar ridge preservation using granulation tissue. In spite of the severe bone defect of the extraction socket, relatively esthetic results could be obtained in implant restorations.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.41
• /
• pp.54.1-54.3
• /
• 2019

Background: The presence of septa increases the risk of Schneiderian membrane perforation during sinus lift procedure, and therefore, the chance of graft failure increases. We present a safe method of managing septa and, in particular, overcoming small and palatally located septa. Methods: After the elevation of the flap and the creation of a small bony window positioned anterior to the septum, the Schneiderian membrane is lifted carefully. A thin and narrow osteotome is then placed at the indentation created at the base of the septum, and mobilization of the septum is achieved by gentle malleting. The membrane is again carefully lifted up behind the septum. Results: There was one small membrane perforation case in all 16 cases, and none of these patients showed postoperative complications such as implant failure, infection, or maxillary sinusitis. Conclusions: This technique is useful for overcoming the problem of maxillary sinus septa hindering the sinus floor elevation procedure, leading to fewer complications.

• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.5
• /
• pp.479-489
• /
• 2008

Statement of the problem: Under anatomical limitations on maxillary posterior region, a poor crown-to root ratio acting on dental implants can result in undesirable stress in surrounding bone, which in turn can cause bone defects and eventual failure of implants. Purpose: The purpose is to compare stress distribution due to different crown-root ratio and effect of splinting between natural teeth and implants in maxillary molar area under different loads. Material and methods: Analysis of stress arising supporting bone of the natural teeth and the implant was made with 3-dimensional finite element method. The model simulated naturel teeth was made with 2nd premolar and 1st molar in the maxillary molar region (Model T). The model simulated implants placed on same positions with two parallel implants of Straumann Dental Implant cemented abutment (Model I). Each model was designed in different crown-root ratio (0.7:1, 1:1, 1.25:1) and set cement type gold crown to make it non-splinted or splinted. After that, 300 N force was loaded to each model in five ways (Load 1: middle of occlusal table, Load 2: middle of buccal cusp, Load 3: middle of lingual cusp, Load 4: horizontal load to buccal cusp of anterior abutment only, Load 5: horizontal load to middle of buccal cusp of each abutment), and stress distribution was analyzed. Results and conclusion: On all occasions, stress was concentrated at the cervical region of the implant. Under load 1, 2 and 3, stress was not increased even when crown-root ratio increases, but under load 4 and 5, when crown-root ratio increases, stress also increased. There was difference in stress values between natural teeth and implants when crown-root ratio gradually increases; In case of natural teeth, splinting decreased stress under vertical and horizontal loads. In case of implants, splinting decreased stress under vertical loads 1,2 and 3, but increased maximal stress under loads 2 and 3. Under horizontal loads, splinting decreased stress, however the effect of splinting decreased under load 5 than load 4. Furthermore, the stress was increased, when crown-root ratio is 1.25:1. Clinical implications: This limited finite element study suggests that the stress on supporting bone may be increased under non-axial loads and poor crown-root ratio. Under poor crown-root ratio, excessive stress was generated at the cervical region of the implant, and decreased splinting effect for stress distribution, which can be related to clinical failure.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.3
• /
• pp.269-281
• /
• 2008

Fatigue or overload can result in mechanical problems of implant components. The mechanical strength in the implant system is dependent on several factors, such as screw and fixture diameters, material, and design of the fixture-abutment connection and abutment. In these factors, the last rules the strength and stability of the fixture-abutment assembly. There have been some previous reports on the mechanical strength of the fixture-abutment assembly with the compressive bending test or short-term cyclic loading test. However, it is restrictive to predict the long-term stability of the implant system with them. The purpose of this study was to evaluate the influence of the design of the fixture-abutment connection and abutment on the mechanical strength and failure mode by conducting the endurance limit test as well as the compressive bending strength test. Tests were performed according to a specified test(ISO/FDIS 14801) in 4 fixture-abutment assemblies of the Osstem implant system: an external butt joint with Cemented abutment (group BJT), an external butt joint with Safe abutment (group BJS), an internal conical joint with Solid abutment (group CJO), and an internal conical joint with ComOcta abutment (group CJT). The following conclusions were drawn within the limitation of this study. Compressive bending strengths were decreased in order of group BJS(1392.0N), group CJO(1261.8N), group BJT(1153.2N), and group CJT(1110.2N). There were no significant differences in compressive bending strengths between group BJT and group CJT(P>.05). Endurance limits were decreased in order of group CJO(600N), group CJT(453N), group BJS(360N), and group BJT(300N). 3. Compressive bending strengths were influenced by the connection and abutment design of the implant system, however endurance limits were affected more considerably by the connection design.

• Journal of Biomedical Engineering Research
• /
• v.19 no.5
• /
• pp.503-511
• /
• 1998

In this study, the stress distribution for different tibial components was observed In order to Investigate the load transfer and potential failure mechanism of the tibial components subjected to dynamic impact loading and also to evacuate the effect of bone-implant bonding conditions on the implant system. The 3-dimensional finite element models included an intact tibia, cemented metal-backed tibial component, uncemented metal-blocked tibial component, cemented all-polyethylene tibial component, and metal-backed component with a debonded bone/stem interface. The results showed that the cemented metal-hocked component Induced slightly higher peak stress at stem tip than the uncemented component. The peak stress of the all-polyethylene tibia1 component at stem trip showed about half thats of metal-backed tibial components. The all-polyethylene component showed a similar dynamic response to intact tibia. In case of debonded bone/stem interface, the peak stress below the metal tray was three times Higher than that of the fully bonded interface and unstable stress distribution at the stem tip was observed with time, which causes another adverse bone apposition and implant loosening. Thus, the all-polyethylene tibial component bonded fully to the surrounding bone might be most desirable system under an impact loading.

• The Journal of Advanced Prosthodontics
• /
• v.3 no.4
• /
• pp.229-235
• /
• 2011

PURPOSE. The aim of this retrospective study was to evaluate cumulative survival rate (CSR) of Implantium implants followed for 5 years and association between risk factors and the CSR. MATERIALS AND METHODS. A total of two hundred forty-nine Implantium Implants System (Dentium, Seoul, Korea) placed in ninety-five patients from 2004 to 2009 were investigated with several identified risk factors (sex, systemic disease, smoking, alchohol, reason of tooth loss, length, arch (maxilla or mandible), replace tooth type (incisor, canine, premolar or molar) Kennedy classification, prosthodontic type, prosthodontic design, opposite dentition, abutment type, occlusal material, occlusal unit, splint to tooth, cantilever, other surgery). Clinical examination (mobility, percussion, screw loosening, discomfort, etc.) and radiographic examination data were collected from patient records including all problems during follow-up period according to protocols described earlier. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR. RESULTS. Five of 249 implants were failed. Four of these were lost before loading. The 5-year implant cumulative survival rate was 97.37%. Cox regression analysis demonstrated a significant predictive association between overall CSR and systemic disease, smoking, reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The screw related complication was rare. Two abutment screw fractures were found. Another complications of prosthetic components were porcelain fracture, resin facing fracture and denture fracture (n=19). CONCLUSION. The 5-year CSR of Implantium implants was 97.37 %. Implant survival may be dependent upon systemic disease, smoking reason of tooth loss, arch, Kennedy classification and prosthodontic design (P<.05). The presence of systemic diseases and combination of other surgical procedures may be associated with increased implant failure.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.2
• /
• pp.141-153
• /
• 2018

A non-physiological occlusal plane caused by continuous tooth loss, occlusal wear, and failure of a prosthesis may result in an unattractive appearance and functional problems, such as reduced masticatory efficiency and occlusal interference. Therefore, when undertaking prosthetic treatment for edentulous patients or patients with a collapsed occlusal plane, it is important to establish an occlusal plane that is compatible with masticatory function. The patient in this case report had undergone restoration of a completely edentulous maxilla using an implant-supported fixed prosthesis. On follow-up examination in the following 6 years, mechanical complications were observed in the existing implant prosthesis, including porcelain chipping, occlusal wear, and screw loosening. Moreover, due to occlusal wear and supraeruption of the opposing anterior teeth, as well as loss of some posterior teeth, the occlusal plane had collapsed. Following diagnosis, the patient underwent full mouth rehabilitation, involving additional implant installation in edentulous sites, recreation of the existing prosthesis, and prosthetic restoration of all remaining teeth.

• Clinics in Shoulder and Elbow
• /
• v.26 no.3
• /
• pp.231-237
• /
• 2023

Background: In the past decade, the number of anatomic total shoulder arthroplasty (aTSA) procedures has steadily increased. Patients over 65 years of age comprise the vast majority of recipients, and outcomes have been well documented; however, patients are opting for definitive surgical treatment at younger ages.We aim to report on the effects of age on the long-term clinical outcomes following aTSA. Methods: Among the patients who underwent TSA, 119 shoulders were retrospectively analyzed. Preoperative and postoperative clinical outcome data were collected. Linear regression analysis (univariate and multivariate) was conducted to evaluate the associations of clinical outcomes with age. Kaplan-Meier curves and Cox regression analyses were performed to evaluate implant survival. Results: At final follow-up, patients of all ages undergoing aTSA experienced significant and sustained improvements in all primary outcome measures compared with preoperative values. Based on multivariate analysis, age at the time of surgery was a significant predictor of postoperative outcomes. Excellent implant survival was observed over the course of this study, and Cox regression survival analysis indicated age and sex to not be associated with an increased risk of implant failure. Conclusions: When controlling for sex and follow-up duration, older age was associated with significantly better patient-reported outcome measures. Despite this difference, we noted no significant effects on range of motion or implant survival. Level of evidence: IV.