• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.53-64
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• 2008

Statement of problem: Peri-implant marginal bone loss is an important factor that affects the success of implants in esthetics and function. Various efforts have been made to reduce this bone loss by improving implant design and surface texture. Previous studies have shown that early marginal bone loss is affected by implant neck designs. Purpose: The purpose of this study was to examine the influence of laser microtexturing of implant collar on peri-implant marginal bone loss. Materials and methods: Radiographical marginal bone loss was examined in patients treated with implant-supported fixed partial dentures. Marginal bone level was examined with 101 implant fixtures installed in 53 patients at three periods(at the time of implantation, prosthetic treatment and 6-month after loading). Four types of implants were examined. The differences of bone loss between implants(ITI standard) with enough biologic width and implants(ITI esthetic plus, Silhouette IC, Silhouette IC Laser-$Lok^{TM}$) with insufficient biologic width have been compared. Resorption angles were examined at the time of prosthetic delivery and 6-month after loading. Results and Conclusion: Within the limitation of this study, the following results were drawn. 1. The marginal bone loss of ITI standard and Silhouette IC Laser-$Lok^{TM}$ was less than that of ITI esthetic plus and Silhouette IC(P<0.05). The marginal bone loss between ITI standard and Silhouette IC Laser-$Lok^{TM}$ had no significant statistical difference(P>0.05). There was no significant statistical difference between marginal bone loss of ITI esthetic plus and Silhouette IC(P>0.05). 2. There was no significant difference in marginal bone loss between maxilla and mandible(P>0.05). 3. There was no significant difference in resorption angle among four types of implants(P>0.05). The marginal bone of implants with supracrestal collar design of less than that of biologic width had resorbed more than those with sufficient collar length. The roughness and laser microtexturing of implant neck seem to affect these results. If an implant with collar length of biologic width, exposure of fixture is a possible complication especially in the anterior regions of dentition that demand high esthetics. Short smooth neck implant are often recommended in these areas which may lack the distance between microgap and the marginal bone level. In these cases, the preservation of marginal bone must be put into consideration. From the result of this study, it may be concluded that laser microtexturing of implant neck is helpful in the preservation of marginal bone.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.2
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• pp.114-119
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• 2018

Purpose: Patients who treated implant immediate loading within a week after implant placement at Wonkwang University Dental Hospital Implant Center were evaluated marginal bone resorption. These retrospective analyses are intended to reinforce the clinical evidence for the implant immediate loading. Materials and methods: Medical history and radiographic data were investigated, which were the patients' who treated implant immediate loading and restoration with provisional prostheses between January 2005 and June 2016, at Wonkwang University Dental Hospital Implant Center. Total number of implants was 70, marginal bone resorption was measured according to implant length, diameter and connection type. To measure marginal bone resorption, periapical radiographs were taken when the implants were placed and after 6 month. Statistical analysis was done in Mann-whitney U test and Kruskal-wallis test with SPSS 22.0 software (P<.05). Results: Mean marginal bone resorption around immediately loaded implants according to implant connection type was shown $1.24{\pm}0.72mm$ in internal hexagon connection type and $1.73{\pm}1.27mm$ in external hexagon connection type. There was no statically significant difference in marginal bone resorption with implant length and diameter. Conclusion: Implants with immediated loading in internal hexagon connection type showed less marginal bone resorption significantly than in external hexagon connection type.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.405-414
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• 2021

Purpose. This study was conducted to evaluate clinical usefulness by evaluating the marginal bone resorption and survival rate of an implant with a taper straight type SLA surface domestically available on the market recently. Materials and methods. 40 implants satisfying the including criteria were observed for one year of 125 implants of 83 adult men and women who had KISPLANT^® implanted from August 2016 to December 2019 at the Department of Periodontology, Chonnam National University Dental Hospital. The marginal bone level was measured on periapical radiographs taken initially and 1 year later and we analyzed implant survival and success rates. A t-test was used for the analysis of the association between the marginal bone resorption and the severity of periodontitis, supportive periodontal therapy, the inserted site, the cause of extraction, immediate placement, and systemic disease. Results. After 1 year of loading, the mesial bone resorption was 0.74 ± 1.07 mm, and the distal bone resorption was 0.53 ± 1.04 mm. The marginal bone resorption of 2 mm or more occurred at 3 implants out of 40 implants after 1 year, so the success rate of implant was 92.5% and survival rate was 100%. There was a significant difference in mesial marginal bone resorption according to the inserted site and no significant differences were found between marginal bone resorption and the other factors. Conclusion. As a result of marginal bone resorption, success rate, and survival rate in this study, we found little marginal bone resorption and high survival and success rate. It can be concluded that they represent excellent clinical results.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.21-28
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• 2012

Purpose: The purpose of this study was to investigate the effects of implant collar design on marginal bone change and soft tissue response by an animal test. Materials and methods: Two types of Implant (Neobiotech Co. Seoul, Korea) that only differs in collar design were planted on two healthy Beagle dogs. The implants were divided into two groups, the first group with a beveled collar (Bevel Group) and the second group with "S" shaped collar (Bioseal group). Standardized intraoral radiographs were used to investigate the mesio-distal change of the marginal bone. Histological analysis was done to evaluate the bucco-lingual marginal bone resorption and the soft tissue response adjacent to the implant. Mann-Whitney test was done to compare the mesio-distal marginal bone change at equivalent time for taking the radiographs and the tissue measurements between the groups. Results: Radiographic and histological analysis showed that there was no difference in marginal bone change between the two groups (P>.05). Histological analysis showed Bioseal group had more rigid connective tissue attachment than the Bevel group. There was no difference in biological width (P>.05). Bevel group showed significantly longer junctional epithelium attachment and Bioseal group showed longer connective tissue attachment (P<.05). Conclusion: For three months there were no differences in marginal bone change between the Bevel group and the Bioseal group. As for the soft tissue adjacent to the implant, Bioseal group showed longer connective tissue attachment while showing shorter junctional epithelium attachment. There were no differences in biologic width.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.99-105
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• 2012

Purpose: The change of the marginal bone around dental implants have significance not only for the functional maintenance but also for the esthetic success of the implant. The purpose of this study was to investigate the load transfer of internal conical joint type implant according to marginal bone resorption by using the three-dimensional finite element analysis model. Materials and methods: The internal conical joint type system was selected as an experimental model. Finite element models of bone/implant/prosthesis complex were constructed. A load of 300 N was applied vertically beside 3 mm of implant axis. Results: The pattern of stress distribution according to marginal bone resorption was similar. The maximum equivalent stress of implant was increase according to marginal bone resorption and the largest maximum equivalent stress was shown at model of 1 mm marginal bone resorption. Although marginal bone loss more than 1mm was occurred increasing of stress, the width of the stress increase was decreasing. Conclusion: According to these results, the exposure of thin neck portion of internal conical joint type implant is most important factor in stress increasing.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.2
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• pp.175-182
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• 2013

The purpose of this study was to observe and analyze the initial marginal bone resorption changes according to the patterns of cover screw exposures during healing period followed by implants installation. Total 64 fixtures(TiUniteTM, NobelBiocare, Sweden) were installed in partially edentulous jaws of 28 patients, who were selected retrospectively and were shown at least one cover screw exposure. Cover screw exposures were defined at 1 month recall. According to the patterns of exposures, groups were categorized into group 1 (No exposure), group 2 (pin-point exposure), group 3 (less than 1/2 of cover screw), group 4 (more than 1/2 of cover screw), group 5 (total exposure). Periapical radiographs were taken in purpose of changes of marginal bone level between installation and 2 month recall. Healing abutments were secured on the exposure groups at 2 month recall. Results were as follows: 1. Marginal bone resorptions were identified whenever cover screws were exposed. 2. Group 2 and 3 were shown significantly increased bone loss more than other group (P <.05). 3. Group 4 and 5 were shown significantly increased bone loss more than group 1, however, less than other groups ( P <.05). Conclusionally, cover screw exposure may cause marginal bone resorptions, therefore, early connection of healing abutment is clinically helpful.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.206-213
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• 2011

Purpose: The aim of this study was to evaluate the clinical value of Osstem$^{(R)}$ USII plus system implants. Clinical and radiographic data were analyzed for 88 implants placed and functionally loaded for a 12 month period at the Yonsei University Dental Hospital. Materials and Method: Based on the patient's medical records, clinical factors and their effects on implant marginal bone resorption, distribution and survival rate were analyzed. The marginal bone loss was evaluated at implant placement and during a 6 to 12 months functional loading period. The independent sample t-test was used to evaluate the interrelationship between the factors (${\alpha}$=0.05), and one way repeated measures ANOVA was used to compare the amount of marginal bone resorption. Results: The cumulative survival rate for 88 implants was 100%. The marginal bone resorption from implant placement to prosthetic delivery was 0.24 mm and the average marginal bone resorption from prosthetic delivery to 12 months of functional loading was 0.19 mm. The total average bone resorption from implant placement to 12 months of functional loading was 0.43 mm. There were no statistically differences in the amount of marginal bone resorption when implants were placed in the maxilla or the mandible (P>.05), however, implants placed in the posterior areas showed significantly more marginal bone loss than those placed in the anterior areas (P<.05). Conclusion: Based on these results, the short term clinical success rate of RBM surface treated external connection domestic implants showed satisfactory results and the marginal bone loss was in accord with the success criteria of dental implants.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.136-147
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• 2009

Statement of problem: Since the introduction of the concept of osseointegration in dental implants, high long-term success rates have been achieved. Though the use of dental implants have increased dramatically, there are few studies on domestic implants with clinical and objective long-term data. Purpose: The aim of this retrospective study was to provide long-term data on the $Implantium^{(R)}$ implant, which features a sandblasted and acid-etched surface and internal connection with microthreads. Material and methods: 106 $Implantium^{(R)}$ implants placed in 38 patients at Yonsei University Hospital were examined to determine the effect of various factors on implant success and marginal bone loss, through clinical and radiographic results during a 6 to 30 month period. Results: 1. Out of a total of 106 implants placed in 38 patients, one fixture was lost, resulting in a 99.1% cumulative survival rate. 2. Among the 96 implants which were observed throughout the study period, the survival rates were 97.0% in the maxilla and 100% in the mandible. The survival rate in the posterior regions was 98.9% and 100% in the anterior regions. 3. The mean bone loss during the first year after prosthesis placement was 0.17 mm, while the mean annual bone loss after the first year was 0.04 mm, which was statistically less than during the first year(P<.05). 4. There was no significant difference in marginal bone loss according to age during the first year(P>.05), but after the first year, the mean annual bone loss in patients above 50 years was significantly greater(P<.05) compared with patients under 50 years. 5. No significant difference in marginal bone loss was found according to the following factors: gender, jaw, location in the arch, type of implant(submerged or non-submerged), presence of bone grafts, type of prostheses, and type of opposing dentition(P<.05). Conclusion: Based on these results, the sole factor influencing marginal bone loss was age, while factors such as gender, jaw, location in the arch, type of implant, presence of bone grafts, type of prostheses and type of opposing dentition had no significant effect on bone loss. In the present study, the success rate of the $Implantium^{(R)}$ implant with a SLA surface and internal connection with microthreads was satisfactory up to a maximum 30 month period, and the marginal bone loss was in accord with the success criteria of dental implants.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.116-126
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• 2018

Purpose: The purpose of this study was to analyze the factors affecting the survival rate and the marginal bone level of dental implants that have functioned over 7-years. Materials and Methods: In 92 patients, 178 dental implants were included. Implant-related factors (diameter, length, prosthetic splint), patient-related factors (gender, smoking, plaque index, compliance to supportive periodontal therapy) and surgery-related factors (proficiency of surgeon, bone graft) were evaluated via clinical and radiographic examination. The marginal bone level was determined by intraoral standard radiography at the mesial and distal aspects of each implant using an image analysis software program. Results: The survival rate of all the implants was 94.94% and the marginal bone level was $0.89{\pm}1.05mm$, these results are consistent with other studies that present long-term good clinical results. Implant length and plaque index among several factors were statistically significant for implant survival rate (P < 0.05). Smoking and the presence of regeneration surgery were statistically significant for the marginal bone level (P < 0.05). Conclusion: Dental implant that have functioned over 7-years showed favorable long-term survival rates and marginal bone level. Implant length and plaque control should be considered for improving the long-term clinical results. It is needed that careful application of bone regeneration technique and smoking control for maintaining of marginal bone level.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.103-109
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• 2016

Purpose: This study is to evaluate the clinical significance of implantation with simultaneous bone graft by comparing the marginal bone loss around maxillary anterior implants with or without bone graft. Materials and methods: Patients treated with implant-retained restorations on maxillary anterior region at Implant Center, Dental Hospital, Wonkwang University between June 2011 and May 2014 were included in this study. Date of implant placement, implant diameter, implant length, implant-abutment connection type and whether the bone graft was done were investigated. The patient's periapical radiographs taken immediately after implantation and at the most recent visit were compared. Marginal bone loss was measured using Emago advanced v5.6 program (Oral diagnostic systems, Amsterdam, Netherlands). Statistical analysis was done in independent t-test by using SPSS 22.0 program. Results: As a result of observing on 83 implants (without bone graft: 44, with bone graft: 39) of 52 patients for 6 - 45 months (average: 18.4 months), implants without bone graft showed $1.42{\pm}0.42mm$, implants with bone graft showed $1.28{\pm}0.45mm$ of marginal bone loss. Conclusion: In limitations of this study, implants with simultaneous bone graft had significantly less marginal bone loss than implants without bone graft.