• The Journal of Advanced Prosthodontics
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• v.14 no.4
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• pp.223-235
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• 2022

PURPOSE. To compare the clinical outcomes of two types of implant restoration for posterior edentulous area, 3-unit bridge supported by 2 implants and 3 implant-supported splinted crowns. MATERIALS AND METHODS. The data included 127 implant-supported fixed restorations in 85 patients: 37 restorations of 3-unit bridge supported by 2 implants (2-IB), 37 restorations of 3 implant-supported splinted crowns (3-IC), and 53 single restorations (S) as controls. Peri-implantitis and mechanical complications that occurred for 14 years were analyzed by multivariable Cox regression model. Kaplan-Meier curves and the multivariable Cox regression model were used to analyze the success and survival of implants. RESULTS. Peri-implantitis occurred in 28.4% of 2-IB group, 37.8% of 3-IC group, and 28.3% of S control group with no significant difference. According to the implant position, middle implants (P2) of the 3-IC group had the highest risk of peri-implantitis. The 3-IC group showed a lower mechanical complication rate (7.2%) than the 2-IB (16.2%) and S control group (20.8%). The cumulative success rate was 52.8% in S (control) group, 62.2% in 2-IB group, and 60.4% in 3-IC group. The cumulative survival rate was 98.1% in S (control) group, 98.6% in 2-IB group, and 95.5% in 3-IC group. There was no significant difference in the success and survival rate according to the restoration type. CONCLUSION. The restoration type was not associated with the success and survival of implants. The risk of mechanical complications was reduced in 3 implant-supported splinted crowns. However, the middle implants of the 3 implant-supported splinted crowns had a higher risk of peri-implantitis.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.453-459
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• 1998

The dental implants for edentulous Patients have been used for more than 20 years. After the introduction of osseointegration by $Br{\aa}nemark$, the commercially pure titanium implants were accepted by most practitioners. Recently dental implants are used for orthodontic anchorages as well as prosthetic abutment. Many researchers have reported implants as a good orthodontic anchorage through basic research and clinical evaluation. But previous researches were done after the healing time for osseointegration of inserted implants. If dental implants are to be used for prosthetic abutment the healing time for osseointegration is necessary, but orthodontic forces to implants are different from bite force regarding its amount of force, duration and direction. The authors evaluated the effect of orthopedic force to implants on bone tissue before osseointegration. 48 implants were placed at 12 rabbits. 2 implants into left side and 2 implants into right side were inserted along the long axis of femur respectively 2 weeks (2 weeks group), 4 weeks (4 weeks group) and 6 weeks (6 weeks group) after implants placement, 300g force had been applied to the implants at left side femur by Ni-Ti close coil spring for 4 weeks (experimental group) and no force applied to implants at right side femur (control group). After the force application for 4weeks, rabbits were sacrificed and microscopic evaluation was done by hematoxylin-eosin stain and Masson trichrome stain. The result3 were followed. 1. All implants in experimental group remained rigid after the force application for 4 weeks. 2. More fibrous tissue between bone and implants were noticed at 2 weeks experimental group than 2 weeks control group 3. More bone remodeling was noticed at 4weeks group than 2 weeks group and it was difficult to find out fibrous tissue between bone and implants at both experimental and control group of 4 weeks group. 4. It was hard to distinguish experimental group from control group at 6 weeks group. Therefore if initial stability can be obtained on implant insertion, it can be possible to use implants as a orthodontic anchorage before the healing time for osseointegration.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.351-358
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• 2013

PURPOSE. This retrospective study analyzed the distribution of the dental implants with regards to age and gender of the patients and type of indication for the implant therapy, as well as the location, dimension and type of the implants. MATERIALS AND METHODS. The data of demographics (age and gender), type of indication for implant therapy, anatomical location, dimensions (length and diameter) and type (bone and tissue level) of 1616 implants were recorded from patient charts between January 2000 and January 2010. Descriptive statistics were analyzed using a chi-squared test for demographic parameters, type of indication, tooth position, anatomical location, implant dimensions and type (${\alpha}$=.05). RESULTS. The patient pool comprised of 350 women and 266 men, with a mean age of $52.12{\pm}13.79$ years. The difference in n% of the implants of the age groups was statistically significant between the types of indications. The difference in the position of the implants was statistically significant between the n% of the implants of all age groups. Gender did not significantly vary, except that the diameter of the implants was significantly higher for the standard diameter implants in males. The difference between the implant positions was statistically significant when considered according to indication. The relationship between implant length and anatomical location was statistically significant. CONCLUSION. The indication for dental implant use is age dependent and the type and size of the implant seems to be strongly related to the location of the implant.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.98-106
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• 2007

Statement of problem: Current tendencies of the implant macrodesign are tapered shapes for improved primary stability, but there are lack of studies regarding the relationship between the implant macrodesign and primary stability. Purpose: The purpose is to investigate the effect of implant macrodesign on the implant primary stability by way of resonance frequency analysis in the bovine rib bones with different kinds of quality. Material and method: Fifty implants of 6 different kinds from two Korean implant systems were used for the test. Bovine rib bones were cut into one hundred pieces with the length of 5 cm. Among them forty pieces of rib bones with similar qualities were again selected. For the experimental group 1, the thickness of cortical part was measured and 20 pieces of rib bones with the mean thickness of 1.0mm were selected for implant placement. For the experimental group 2, the cortical parts of the remaining 20 pieces of rib bones were totally removed and then implants were placed on the pure cancellous bone according to the surgical manual. After placement of all implants, the implant stability quotient(ISQ) was measured by three times, and its statistical analysis was done. Results: There are statistically significant differences in ISQ values among 4 different kinds of Avana system implants in the experimental group 2. For the experimental group 1, Avana system implants showed significantly different ISQ values, but when differences in the thickness of cortical parts were statistically considered, did not show any significant differences in ISQ values. Among Oneplant system implants, there are no significant differences in ISQ values for the experimental group 2 as well as for the experimental group 1. Conclusion: Within the limits of this study, bone quality and implant design have some influences on the primary stability of implants. Especially in the bone of poor quality, tapered shape of implants are more favorable for the primary stability of implants.

• 대한치주과학회:학술대회논문집
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• 2007.11a
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• pp.186-187
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• 2007

• Journal of Korean Dental Science
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• v.6 no.2
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• pp.67-77
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• 2013

Purpose: The purpose of this study was to evaluate the survival and success rates of Korean Osstem implants US II Plus, GS II following loading period. Materials and Methods: Dental records were obtained in total 201 patients who were treated with Korean Osstem implants US II Plus, GS II on both maxillary and mandibular anterior and posterior areas in six different clinics for 2 years from January 2007 to December 2008. Total 430 implants were evaluated clinically and radiographically using predefined success criteria prospectively and following results were obtained. Result: US II Plus, GS II implants showed high survival rates of more than 99% and high success rates more than 90% independent of loading period. As a result of cross analysis to evaluate clinical significance between implant loading period and success rate, the P-value of US II Plus was 0.10 (P>0.05), and the P-value of GS II was 0.17 (P>0.05), which showed no statistical significance. Bone quality, smoking, and edentulous state are factors that can affect the survival and success rates following differently loaded implants, but did not significantly affect in this study. Conclusion: These results suggest that selection of loading period of Korean Osstem implants US II Plus, GS II would be done carefully considering implant install area, the quality alveolar bone, the state of edentulous ridge and experience of operator, though they showed clinically good results on both maxillary and mandibular anterior and posterior areas.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.258-265
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• 2008

Purpose. This multicenter retrospective study was performed to evaluate the survival and success rates of immediate placement of USII and SSII Osstem implant (Osstem implant Co, Korea) on the maxillary and mandibular anterior and premolar areas. Materials and methods. Dental records were obtained in 37 patients who were treated with immediate implantation on the maxillary and mandibular anterior and premolar areas in 6 different clinics. The 98 implants were evaluated both clinically and radiographically using predefined success criteria. Results. There was no failed implant in all patients. The mean follow up period was 24.7 months (ranged from 12 to 58 months), and 25.1 months (ranged from 16 to 35 months) in USII and SSII implants, respectively. The crestal bone loss was 3 mm in 3 USII implants during 41 months, and in 1 SSII implant during 22 months. The overall success rate was 94.2% and 97.7% in USII and SSII implants, respectively. The age, gender, diameter, or length of implants, and type of surgery were not influenced to the success rate of immediate implantation. Conclusion. These results suggest that USII and SSII Osstem implant can be used successfully in immediate implantation on the maxillary and mandibular anterior and premolar areas.

• Journal of Technologic Dentistry
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• v.42 no.4
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• pp.348-354
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• 2020

Purpose: Zirconia is differentiated from other ceramics because of its high resistance to corrosion and wear, excellent flexural strength (900~1400 MPa), and high hardness. Dental zirconia with proven mechanical/biological stability is suitable for the manufacture of implants. However, there are limited in vivo studies evaluating stress distribution in zirconia compared with that in titanium implants and studies analyzing finite elements. This study was conducted to evaluate the stress distribution of the supporting bone surrounding zirconia and titanium implants using the finite element analysis method. Methods: For finite element analysis, a single implant-supported restoration was designed. Using a universal analysis program, eight occlusal points were set in the direction of the occlusal long axis. The occlusal load was simulated at 700 N. Results: The zirconia implant (47.7 MPa) von Mises stress decreased by 5.3% in the upper cortical bone compared with the titanium implant (50.2 MPa) von Mises stress. Similarly, the zirconia implant (20.8 MPa) von Mises stress decreased by almost 4% in the cancellous bone compared with the titanium implant (21.7 MPa) von Mises stress. The principal stress in the cortical and cancellous bone exhibited a similar propensity to von Mises stress. Conclusion: In the supporting bone, the zirconia implant is able to reduce bone resorption caused by mechanically transferred stress. It is believed that the zirconia implant can be a potential substitute for the titanium implant by reinforcing aesthetic characteristics and improving stress distribution.

• Imaging Science in Dentistry
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• v.50 no.4
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• pp.281-290
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• 2020

Purpose: The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α=0.05). Results: The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r=0.232, P<0.05). Conclusion: There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.

• Journal of Periodontal and Implant Science
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• v.54 no.3
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• pp.177-188
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• 2024

Purpose: Placing dental implants in areas with low bone density or in conditions where bone healing is suppressed is challenging for clinicians. An experiment using a rodent model was performed with the aim of determining the efficacy of host modulation by increasing the systemic level of cholesterol sulfate (CS) using Irosustat in the context of the bone healing process around dental implants. Methods: In 16 ovariectomised female Sprague-Dawley rats, 2 implant fixtures were placed in the tibial bones (1 fixture on each side). At 1 week after surgery, the high-CS group (n=8) received Irosustat-mixed feed, while the control group (n=8) was fed conventionally. Block specimens were obtained at 5 weeks post-surgery for histologic analysis and the data were evaluated statistically (P<0.05). Results: Unlike the high-CS group, half of the specimens in the control group demonstrated severe bone resorption along with a periosteal reaction in the cortex. The mean percentages of bone-to-implant contact (21.5%) and bone density (28.1%) near the implant surface were significantly higher in the high-CS group than in the control group (P<0.05), as was the number of Haversian canals (by 5.3). Conclusions: Host modulation by increasing the CS level may enhance the osseointegration of dental implants placed under conditions of impaired bone healing.