• Journal of Periodontal and Implant Science
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• 제38권4호
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• pp.611-620
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• 2008

Purpose: The purpose of this study was to assess the long term survival rates of the most posterior single tooth implant and to evaluate the influence of implant characteristics on implant survival. Material and Methods: This retrospective report presents findings on 37 patients with 43 implants replacing single molars. The inclusion criteria were having implants replacing a molar of the most posterior region and follow-up data over at least 6 months. Data were recorded regarding the incidence of complications and survival rates of these implants. Results: The range of follow-up was from 9 to 66 months(mean: 40.2 months). The cumulative survival rate of total implants was 93.0% which reflects the loss of three implants: one had broken neck, one implant failed because of infection, one implant showed failed osseointegration. Abutment- screws loosening occurred in five implants(11.6%). Conclusion: Within the limits of this study, a single tooth-implant can serve as a good long-term and predictable treatment modality to replace the most posterior teeth with low complication and failure rates.

• Journal of Periodontal and Implant Science
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• 제33권3호
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• pp.383-393
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• 2003

The aim of this retrospective study was to compare the amount of marginal bone loss between upper anterior area and upper posterior area with 71 upper single-tooth restorations on 2 stage machined $Br{{\aa}}nemark$ implants since Jan 1995. The second aim was to compare the bone defect group which had dehiscence and fenetration and the others in the upper anterior region. The results were as follows. 1. The most frequent reason of missing tooth in the upper anterior region was trauma by 61%. While upper posterior region showed various reasons such as congenital missing, advanced periodontitis, trauma. 2. Peri-implantitis with fistula occurred 1 of 41 implants in the upper anterior group in 1 year after loading and 2 of 32 implants in the upper posterior group failed before loading. The 1 year success rate of upper anterior group was 97.56 %, and 93.75 % for upper posterior group. 3. The mean marginal bone loss in the upper anterior group was 0.44${\pm}$0.25 mm, while 0.57${\pm}$0.32 mm in the upper posterior group. There was statistically significant difference in the amount of mean marginal bone loss (P${\pm}$0.10 mm at one year, and 0.48${\pm}$0.26 mm for the control group. No statistically significant difference of mean marginal bone loss was showen between bone defect group and the others at implantation. According to the results, the upper anterior region showed less marginal bone loss than the upper posterior region. In case of missing single upper tooth, careful consideration on recipient residual ridge to determine proper implant diameter and length, sufficient healing time, proper loading would lead to implant success. Single tooth implants in the maxilla seemed to be an alternative to fixed partial dentures without damage to adjacent teeth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.248-252
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• 2009

Purpose: This retrospective study was performed to analyze the relationship between complications of the posterior mandibular single crowns and distance from the adjacent teeth to the implant. Subjects and Methods: Of the patients who presented Ewha Womans University Mokdong Hospital & Yonsei University Dental Hospital with missing of the posterior mandibular molar and restored with implant-supported 18 Single crowns between 1996 thru 2007, 115 patients had been followed after crown delivery. The subjects were divided into complication-followed group and a control without any problems. The distance from the most distal tooth to the implant were measured. The prosthetic & biologic complications were reviewed by the cantilever distance and analyzed by abutment type, age & gender statistically using SAS version 9.1 (SAS Inc., USA). Results and Conclusion The results were as follows; 1) The posterior mandibular single crown with cantilever showed higher incidence of follow-up complications upon logistic analysis (p<0.05). 2) The prosthetic and biologic complications are related with the cantilever distance with 2.1 odds ratio and 3.39 cut-off value of specificity & sensitivity by SPSS 12.0. 3) The complications are neither significant in abutment types nor age & gender.

• The Journal of Advanced Prosthodontics
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• 제1권3호
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• pp.140-144
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• 2009

STATEMENT OF PROBLEM. Little information is available about the buccal gingival level of multiple implant restorations. PURPOSE. This study was aimed to evaluate the relationship between width and height of buccal soft tissue around single and 2 adjacent implant restorations. MATERIAL AND METHODS. Four implant restoration groups (first and second molars, single second molars, posterior single restorations between teeth, and anterior single restorations between teeth) were randomly chosen from one dental institute. Each group comprised of 6 patients. After 6 months of function, silicone impressions were taken and stone models were fabricated for each restoration group. The stone models were cut in bucco-lingual direction at the most apical point of buccal gingival margin. The height and width of buccal supra-implant soft tissue were measured. One way ANOVA and Tukey HSD post hoc tests were performed to analyze the data obtained (P < .05). RESULTS. The most unfavorable width-height ratio was noted for the group, which was comprised of the second molar in the multiple adjacent (first and second molar) implant-supported restorations. The group also resulted in the shorter height of buccal supra-implant mucosa rather than that of anterior single implant restorations between natural teeth. CONCLUSION. To achieve a favorable level of buccal gingival margin, greater thickness of buccal supra-implant mucosa is required for the implant restorations without a neighboring natural tooth compared to the implant restorations next to a natural tooth.

• Journal of Periodontal and Implant Science
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• 제34권4호
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• pp.819-836
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• 2004

Nowdays, the awareness of implant treatment has grown rapidly among dentists and patients alike in Korea, as it becomes a widely accepted treatment. The reason is that unlike crown and bridge or denture treatment, implant treatment helps preserve existing bone and improve masticatory functions. So, It is needed understanding about the type, distribution of implant patient. The following results on patient type and implant distribution were compiled from 4433 implant cases of 1596 patients treated at the periodontal dept. of Y University Hospital during 1992 to 2004. 1. There are no dissimilarities between men and women, with patients in their 40, 50s accounting for 52.5% of patients and 57.5% of implant treatments; the largest share of patients and implant treatments. 2. Mn. posterior area accounted for 54.9% of implant treatments followed by Mx. posterior area(27.6%), Mx anterior area(11.9%) and Mn anterior area(5.6%). 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 97.5% and fully edentulous patient accounted for the remaining 2.5%. 4. The major cause of tooth loss is periodontal disease, followed by dental caries, trauma and congenital missing. Also, older people are more likely to suffer from tooth loss due to periodontal disease rather than dental caries. 5. In the distribution of bone quality for maxillae, type III was most, followed by type II, r type IV and r type I. As for mandible, type II was most, followed by type III, type IV and for type I. 6. In the distribution of bone quantity for maxillae, type C was most, followed by type B, type D, type A, and for type E. As for mandible, type B was 52% most, followed by type C, type D, type A and type E. 7. The majority of implants were those of 1O-14mm in length (85.2%) and regular diameter in width (64%). The results provided us with basic data on patient type, implant distribution, bone condition, etc. We wish that our results coupled with other research data helps assist in the further study for better implant success/survival rates, etc.

• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.150-157
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• 2016

PURPOSE. The modified lateral-screw-retained implant prosthesis (LSP) is designed to combine the advantages of screw- and cement-retained implant prostheses. This retrospective study evaluated the mechanical and biological complication rates of implant-supported single crowns (ISSCs) inserted with the modified LSP in the posterior region, and determined how these complication rates are affected by clinical factors. MATERIALS AND METHODS. Mechanical complications (i.e., lateral screw loosening [LSL], abutment screw loosening, lateral screw fracture, and ceramic fracture) and biological complications (i.e., peri-implant mucositis [PM] and peri-implantitis) were identified from the patients' treatment records, clinical photographs, periapical radiographs, panoramic radiographs, and clinical indices. The correlations between complication rates and the following clinical factors were determined: gender, age, position in the jaw, placement location, functional duration, clinical crown-to-implant length ratio, crown height space, and the use of a submerged or nonsubmerged placement procedure. RESULTS. Mechanical and biological complications were present in 25 of 73 ISSCs with the modified LSP. LSL (n=11) and PM (n=11) were the most common complications. The incidence of mechanical complications was significantly related to gender (P=.018). The other clinical factors were not significantly associated with mechanical and biological complication rates. CONCLUSION. Within the limitations of this study, the incidence of mechanical and biological complications in the posterior region was similar for both modified LSP and conventional implant prosthetic systems. In addition, the modified LSP is amenable to maintenance care, which facilitates the prevention and treatment of mechanical and biological complications.

• Journal of Periodontal and Implant Science
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• 제34권1호
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• pp.101-112
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• 2004

Osseointegrated implnats have proven to be successful in both full and partial edentulous patients since the 1960s and recently have shown successful results when used to restore single tooth missing. However, in most studies reporting the success of single implants, single implants replacing anterior teeth are more frequently mentioned than posterior single implants. Moreover, in studies regarding posterior single implants, the replaced region seemed to be variable; the maxilla, mandible and areas from the first premolar to the second molar were mentioned. However, considering the difference in bone quality in the mandible and maxilla, and the increased occlusal force in the posterior region, the success rates in each region may be different. In this study, the cumulative success rates and amount of bone loss of single implants replacing the mandibular first and second molar, respectively, were compared and analyzed to come to the following conclusion. 1. The 20 (20 persons) single implants that were placed in the mandibular first molar region were all successful and showed a 100% 5 year cumulative success rate. Among the 27 (24 persons) single implants replacing the mandibular second molar, 8 failed (27.63%) showing a 5 year cumulative success rate of 70.37%. 2. Among the 8 failed implants, one showed symptoms of postoperative infection and one complained of parenthesia. 6 implants failed after functional loading; 5 showed mobility and one resulted in fixture fracture. 3. After the attachment of the prosthesis, there was no significant statistical difference regarding the marginal bone loss in group 1 and group 2 during the checkup period (P>0.05). In conclusion, restoration of the mandibular first molar using single implants was found to be an excellent treatment modality, and when replacing mandibular second molars with single implants, poor bone quality and risk of overloading must be considered.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.805-824
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• 2007

Purpose: Developments in micro/macrostructures of implants and surgical techniques brought out stable outcomes of implant dentistry. The aim of this study was to evaluate the distributions of implant patients, the types of implanted sites, and the success or survival rates of various implant systems and to analyze the implant placement done at each specificintraoral site and situation. Materials and Methods: The data of dental implantations collected between 1992 and 2006 at the Department of Periodontology in 00000 University Hospital were analyzed. Results: 1. Largest part of the patients were at the age of 40s and 50s in bothgender who lost their teeth mostly by periodontaldiseases and caries at the posterior intraoral sites as major ones. Bone densities of type II(mandible) and III(maxilla) were likely to be seen with quantity of type B. Lengths of the implants between 10 and 15 mm and wide platform took the largest part. 2. Survival rates of $Implantium^{(R)}(98.8%)$, $Xive^{(R)}(100%)$ and ITI $TE^{(R)}(100%)$ were high when $Frialit-2^{(R)}$ showed 82%(poor bone density area) or 87.2%(combined with additional therapy). $IMZ^{(R)}$ had lowest cumulative survival(67.5%) and success rate(49.4%) amongst all. 3. Replacement with 2 wide or 3 regular platforms showed no significant differences in survival rate and marginal bone loss atmandibular posterior area. In single restoration of mandibular second molar, 5-year success rate of machined surface $Br{\aa}nemark^{(R)}(70.37%)$ was lower than that of rough surface $ITI^{(R)}$ SLA(100%). 4. Replacement of single tooth in anterior area showed high survival rate of 94.5%. 5. The success rates of $Br{\aa}nemark$ Ti-Unite and ITI SLA at posterior maxilla with poor bone density both showed stable outcomes. 6. 10-year cumulative survival rate of implants with maxillary sinus augmentation by lateral window approach appeared to be 96.60%. Low survival rate(75%) was shown when there were more than two complications combined. Height of grafted bone remained stable above the implant apex. Conclusions : Rough surfaced implants showed stable outcomes in most of the situation including poor bone density and additional therapy combined.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.523-534
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• 2007

This study is an analysis of types of patients and distribution of implant site and survival rate of $Xive^{(R)}$ implant. The following results on patient type, implant distribution and survival rate were compiled from 324 implant cases of 140 patients treated at the periodontal dept. of Yonsei University Hospital and G dental clinic between February 2003 and April 2006. 1. There are no dissimilarities between men and women, with patients in their 30, 40, 50s accounting for 80% of patients and accounted for 82% of implant treatments; the largest share of patients and implant treatments. 2. Mn, posterior area. accounted for 57% of implant treatments followed by Mx. posterior area(29%), Mx, anterior area(8%) and Mn, anterior area(6%). 3. Partial edentulous patients treated by single crown and bridge-type prosthesis accounted for 96% and fully edentulous patient accounted for the remaining 4%. 4. The major cause of tooth loss is periodontal disease, followed by dental canes, trauma and congenital missing. 5, The distribution of bone quality for maxillae was 54,2% for type III, followed by 30.8% for type II, 15% for type IV and 0% for type I. As for mandible, the distribution was 63% for type II, followed by 34% for type III, 2,5% for type I and 0,5% for type IV. 6. The distribution of bone quantity for maxillae was 55% for type C, followed by 35% for type B, 8% for type D and 2% for type A. As for mandible, the distribution was 60% for type B, followed by 32% for type C, 7% for type A and 0% for type D. 7. The majority of implants were those of 9.5-13 mm in length(95%) and regular diameter in width(82%). 8. The total survival rate was 98%. The survival rate was 97% in the maxillae region and 99% in the mandible region. 9. The survival rate in type I was 83%, in type II was 99%, in type III was 97% and in type IV was 100%. As for the bone quantity, the survival rate in type A and D(100%) was most, followed by type B(99%) and type C(96%). The results showed that $Xive^{(R)}$ implant could be used satisfactorily compare for the other implant system. But we most to approach carefully in certain extreme condition especially with poor bone quality and quantity.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.673-682
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• 2006

Recent study shows that implant design has a great impact on initial stability in bone. The ITI $TE^{(R)}$ implant, designed originally for immediate placement has a tapered/ cylindrical form which fits the anatomical shape of the natural alvelous or tooth root. The increased diameter at the collar region coupled with more threads lead to more bone contact and enhanced stability. The aim of this retrospective study is to evaluate the clinical use and the efficacy of recently introduced ITI TE implant with a new macro-design. The following results are compiled from 139 patients who received ITl TE implant surgery at the periodontal department. of Yonsei University Hospital between July 2002 and September 2005. 1. 139 patients received 173 ITl $TE^{(R)}$ implants in their maxilla and mandible (Mx 82, Mn 91). Posterior area accounted for 84% of the whole implant surgery, 2. In the distribution of bone quality, type III(41,0%) was the most, followed by type IV(41,0%) and type II (27.7%). As for the bone quantity, type B(43.9%) was the most, followed by type C(42.2%), type D(12.2%) and type A(1.7%). 3. 125 implants(83.9%) were treated by single crown, which accounted for the majority. 4, The total implant survival rate was 100% after a mean follow-up period of 21.2 months. This preliminary data with ITl $TE^{(R)}$ implant showed excellent survival rate although the majority of implants evaluated in this study were placed in the posterior region of the jaw and compromised sites.