• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.227-234
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• 2012

PURPOSE. The aims of this pilot study were to introduce implant loading devices designed for animal study and to evaluate the validity of the load transmission ability of the loading devices. MATERIALS AND METHODS. Implant loading devices were specially designed and fabricated with two implant abutments and cast metal bars, and orthodontic expansion screw. In six Beagles, all premolars were extracted and two implants were placed in each side of the mandibles. The loading device was inserted two weeks after the implant placement. According to the loading protocol, the load was applied to the implants with different time and method, simulating early, progressive, and delayed loading. The implants were clinically evaluated and the loading devices were removed and replaced to the master cast, followed by stress-strain analysis. Descriptive statistics of remained strain (${\mu}{\varepsilon}$) was evaluated after repeating three cycles of the loading device activation. Statistic analysis was performed using nonparametric, independent t-test with 5% significance level and Friedman's test was also used for verification. RESULTS. The loading devices were in good action. However, four implants in three Beagles showed loss of osseointegration. In stress-strain analysis, loading devices showed similar amount of increase in the remained strain after applying 1-unit load for three times. CONCLUSION. Specialized design of the implant loading device was introduced. The loading device applied similar amount of loads near the implant after each 1-unit loading. However, the direction of the loads was not parallel to the long axis of the implants as predicted before the study.

• Journal of Periodontal and Implant Science
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• v.53 no.2
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• pp.99-109
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• 2023

Purpose: The aim of this systematic review was to evaluate the effectiveness of the socket shield technique (SST), an innovative surgical method introduced in 2010, for reducing buccal bone plate resorption. Methods: The review was conducted following the PRISMA guidelines. Clinical studies conducted in humans and investigating the SST were searched on PubMed (MEDLINE), Embase, Web of Knowledge, and Google Scholar in November and December 2021. The implant survival rate, percentage of complications, and clinical parameters (marginal bone loss [MBL], pink esthetic score [PES], and buccal bone plate resorption [BBPR]) were analyzed using the collected data. Results: The initial search resulted in 132 articles. After article screening, the full texts of 19 studies were read and 17 articles were finally included in the review. In total, 656 implants were installed with the SST. Nine of the 656 implants experienced failure, resulting in an implant survival rate of 98.6%. The percentage of complications was about 3.81%. The analysis of clinical parameters (MBL, PES, and BBPR), showed favorable results for the SST. The mean MBL in implants placed with the SST was 0.39±0.28 mm versus 1.00±0.55 mm in those placed without the SST. PES had a better outcome in the SST group, with an average of 12.08±1.18 versus 10.77±0.74. BBPR had more favorable results in implants placed with the SST (0.32±0.10 mm) than in implants placed with the standard technique (1.05±0.18 mm). Conclusions: The SST could be considered beneficial for preserving the buccal bone plate. However, since only 7 of the included studies were long-term randomized controlled trials comparing the SST with the standard implant placement technique, the conclusions drawn from this systematic review should be interpreted with caution.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.250-262
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• 2007

Statement of problem: It was reported high success rate of implant-supported fixed prostheses using with $5{\sim}6$ implants on anterior mandible. Recently, immediate loading protocol was focused to overcome disadvantages of classic 2-stage delayed loading protocol. Purpose: This clinical study was to evaluate stability changes with time of immediately loaded and delayed loaded implants in edentulous mandible and to compare stability changes with time according to implantation sites. Materials and methods: Five or six implants were placed on anterior mandible depending on the arch shape. The immediately loading group was consisted of 8 patients received their prostheses within $24{\sim}48$ hours after implantation. The delayed loading group was consisted of 8 patients received their definitive prostheses following classical prosthetic procedures after a healing period of 3 months. All patients were recalled every 6 months for check-up. The evaluations of radiographic examination, ISQ value measurement and recording of complication were done. To evaluate marginal bone level, intraoral periapical radiographs were taken with long cone paralleling technique. At every evaluation recall, all prostheses were removed and ISQ values were measured with OsstellTM on individual implants. Results: 1. None of implants was failed. All implants showed stable marginal bone levels and ISQ values. 2. Marginal bone level changes with time showed statistically significant difference between immediately loading group and delayed loading group (P<0.001). 3. ISQ value changes with time did not show statistically significant difference between immediately loading group and delayed loading group (P=0.079). ISQ value decreased with time in both groups, however, all implants showed stable ISQ value at 30 months-recall evaluation. 4. Marginal bone level changes with time did not show statistically significant differences among implantation sites (P=0.604). 5. ISQ value changes with time showed statistically significant differences among implantation sites (P=0.047). ISQ values of most posterior implants decreased with time comparing to other implants. Conclusion: Although the marginal bone level of the terminal abutment didn't different with the other implants, ISQ value of the terminal abutment was lower than that of the other implants. Therefore, further clinical evaluation would be needed in this point of view.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.4
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• pp.204-211
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• 2012

Objectives: Dental implants installation in patients with diabetes remains controversial as altered bone healing around implants has been reported. And little is known about the biological factors involved in bone healing around implants. The present study aimed to investigate the biological markers around immediately placed implants in rats with controlled and uncontrolled diabetes. Materials and Methods: Twenty rats (40 sites) were divided into the control, insulin-treated and diabetic groups. The rats received streptozotocin (60 mg/kg) to induce diabetes; animals in the insulin-treated group also received three units of subcutaneous slow-release insulin. Two threaded titanium alloy implant ($1.2{\times}3mm$) were placed in the extraction socket of the both maxillary first molars and allowed for healing. Bone blocks including implant were harvested at 3 days, 1, 2 and 4 weeks. The levels of bone morphogenetic protein (BMP)-4, transforming growth factor (TGF)-${\beta}1$, osteocalcin (OC) and osteonectin (ON) were measured in the peri-implant osseous samples by RT-PCR. Results: The BMP-4 level increased immediately in all groups by day 3, then decreased abruptly in the control and the insulin-treated groups. However, by week 4, all groups showed mostly the same amount of BMP-4 expression. The level of TGF-${\beta}1$ also instantly increased by day 3 in the insulin-treated group. This level elevated again reaching the same values as the control group by week 4, but was not as high as the diabetic group. In addition, the expression of OC and ON in the control and insulin-treated groups was higher than that of the diabetic group at 2 weeks and 4 weeks, indicating active bone formation in these groups. Conclusion: The immediate placement of titanium implants in the maxilla of diabetic rat led to an unwanted bone healing response. Conclusively, the results of this study suggest that immediate implant insertion in patients with poorly controlled diabetes might be contraindicated.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.400-410
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• 1993

Dental implants have been widely used in the treatment of esthetic and functional problems of the mouth due to alveolar bone loss, after tooth extraction. The success of implantation strongly depends on osseointegration. For osseointegration, implant material, methodology, and design have been investigated. For materials, two popular materials at present are titanium and hydroxyapatite. For methods, immediate implantation is being used recently. The purpose of this study is to evaluate osseointegration between the unthreaded cylindrical TPS implant and the HA-coated implant by a histomorphometric analysis. For this analysis, experimental periodontits was induced on the 3, 4 premolars of adult dogs by the ligation of orthodontic threads. Thereafter, each tooth was extracted. TPS. Implants and HA-coated implants were immediately inserted in the extraction socket. In control group, TPS implants were immediately inserted, and In experimental group, HA implants were immediately inserted. The dogs were sacrificed after 12 weeks, then the specimens were prepared for LM and histomorphometric analysis. The conclusion of this study is as follows l. In both control and experimental group, no inflammatory cells were observed. 2. The results of the histomorphometric analysis showed that the total osseointegration was 48.5% in control group, and 68.8% in expermental group. The experimental group was higher than the control group, and the difference was not statistically significant (p<0.05). 3. The results of the histomorphometric analysis showed that the osseointegration in the hole was 40.6% in control group, and 70.2% in experimental group. The experimental group was higher than the control group, and the difference was statistically significant (p<0.05). In both control and experinental group, no inflammatory cells were observed. 4. The results of the histomorphometric analysis showed that the osseointegration in the lower part was 52.1% in control group, and 73.3% in experimental group. The experimental group was higher than the control group, and the difference was statistically significant (p<0.05). 5. In experimental group, the bone to HA interface seemed to be mixed of bone and HA. We could not distinguish HA from the bone. The HA coating was detached from the titanium surface.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.209-221
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• 2007

Recently, immediately after losing teeth. implant placement has been greatly attempted. Implant can help restoration of tooth functions within short time. This study was an attempt to examine the extent of osseointergation when the implants will be placed immediately after teeth extraction using domestic implant systems. Implants were inserted in beagle dogs and evaluated the clinical, radiological, histological and histomorphometric assay at 6 weeks and 12 weeks. For experimental materals, $STAGE-1^{(R)}$($4.1{\times}8mm$, Lifecore, USA), $SS-III^{(R)}$($4.0{\times}8mm$, OSSTEM, Korea) and $IFI^{(R)}$($4.0{\times}8mm$, Dio, Korea) implants treated with RBM were placed. All the placed site showed normal results without fail and inflammation clinically and radiologically. As a result of measurement by periotest, it showed $-2\;{\sim}\;-5$ and stable status comprehensively. There was no statistically significant difference among implants(p<0.05). Bone tissue adjacent to implant showed increased marrow tissue at 6 weeks. Nevertheless, osteogenic structure was not observed remarkably. In a 12 weeks opinion, bone tissue composed of osseointegration along implant interface showed significantly decreased marrow tissue containing central vessels unlike a 6 weeks opinion and matured compact bone whose osteogenic structure is well formed. BIC were 42.4%, 32.0% and 34.9%, respectively in 6 weeks and there was no statistically significant difference among group(p<0.05). In 12 weeks, BIC were 58.8%, 61.9% and 57.5%. respectively and there was no statistically significant difference among groups(p<0.05). It is considered that all 3 implant systems are suitable for immediate implant placement.

• Journal of Periodontal and Implant Science
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• v.47 no.4
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• pp.251-262
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• 2017

Purpose: The purpose of this study was to investigate the effects of implant tilting and the loading direction on the displacement and micromotion (relative displacement between the implant and bone) of immediately loaded implants by in vitro experiments and finite element analysis (FEA). Methods: Six artificial bone blocks were prepared. Six screw-type implants with a length of 10 mm and diameter of 4.3 mm were placed, with 3 positioned axially and 3 tilted. The tilted implants were $30^{\circ}$ distally inclined to the axial implants. Vertical and mesiodistal oblique ($45^{\circ}$ angle) loads of 200 N were applied to the top of the abutment, and the abutment displacement was recorded. Nonlinear finite element models simulating the in vitro experiment were constructed, and the abutment displacement and micromotion were calculated. The data on the abutment displacement from in vitro experiments and FEA were compared, and the validity of the finite element model was evaluated. Results: The abutment displacement was greater under oblique loading than under axial loading and greater for the tilted implants than for the axial implants. The in vitro and FEA results showed satisfactory consistency. The maximum micromotion was 2.8- to 4.1-fold higher under oblique loading than under vertical loading. The maximum micromotion values in the axial and tilted implants were very close under vertical loading. However, in the tilted implant model, the maximum micromotion was 38.7% less than in the axial implant model under oblique loading. The relationship between abutment displacement and micromotion varied according to the loading direction (vertical or oblique) as well as the implant insertion angle (axial or tilted). Conclusions: Tilted implants may have a lower maximum extent of micromotion than axial implants under mesiodistal oblique loading. The maximum micromotion values were strongly influenced by the loading direction. The maximum micromotion values did not reflect the abutment displacement values.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.535-543
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• 2019

Background A high incidence of breast animation deformity (BAD) has been reported following immediate breast reconstruction with subpectorally placed implants. The aim of this study was to assess and compare the incidence of BAD in women who underwent either subpectoral or prepectoral immediate breast reconstruction. Therefore, we developed a grading tool and tested its reproducibility in a clinical setting. Methods Video recordings of 37 women who had undergone unilateral or bilateral immediate breast reconstruction were evaluated by two consultant plastic surgeons. The degree of BAD was assessed by our grading tool, named the Nipple, Surrounding Skin, Entire Breast (NSE) grading scale, which evaluates the degree of tissue distortion in three areas of the breast. Blinded assessments were performed twice by each observer. Results Eighteen patients were reconstructed with subpectoral implant placement and 19 with prepectoral implant placement. Using the NSE grading scale, we found a significant difference in the degree of BAD between the groups, in favor of patients who underwent prepectoral immediate breast reconstruction (0.2 vs. 4, P=0.000). Inter- and intraobserver agreement was moderate (74%) to strong (88%). Conclusions The incidence and severity of BAD was significantly lower in women reconstructed with a prepectorally placed implant than in those who underwent subpectoral immediate breast reconstruction. All patients reconstructed using the subpectoral technique had some degree of BAD. The inter- and intraobserver agreements were high when using the NSE grading scale, suggesting it is an easy-to-use, reproducible scale for assessing BAD in women who undergo immediate breast reconstruction.

• Archives of Plastic Surgery
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• v.43 no.6
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• pp.523-528
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• 2016

Background The use of acellular dermal matrix (ADM) in implant-based immediate breast reconstruction has been increasing. The current ADMs available for breast reconstruction are offered as aseptic or sterile. No published studies have compared aseptic and sterile ADM in implant-based immediate breast reconstruction. The authors performed a retrospective study to evaluate the outcomes of aseptic versus sterile ADM in implant-based immediate breast reconstruction. Methods Implant-based immediate breast reconstructions with ADM conducted between April 2013 and January 2016 were included. The patients were divided into 2 groups: the aseptic ADM (AlloDerm) group and the sterile ADM (MegaDerm) group. Archived records were reviewed for demographic data and postoperative complication types and frequencies. The complications included were infection, flap necrosis, capsular contracture, seroma, hematoma, and explantation for any cause. Results Twenty patients were reconstructed with aseptic ADM, and 68 patients with sterile ADM. Rates of infection (15.0% vs. 10.3%), flap necrosis (5.0% vs. 7.4%), capsular contracture (20.0% vs. 14.7%), seroma (10.0% vs. 14.7%), hematoma (0% vs. 1.5%), and explantation (10.0% vs. 8.8%) were not significantly different in the 2 groups. Conclusions Sterile ADM did not provide better results regarding infectious complications than aseptic ADM in implant-based immediate breast reconstruction.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.71-76
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• 2009

Purpose: Many researches showed loss of alveolar bone in fresh extraction socket and even in case of immediate implant placement. The aim of this study was to evaluate the effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets. Materials and methods: Immediate implants were placed into artificially induced periapical lesion of mandibular premolars after complete debridement using buccal bone defect made by a 6mm trephine bur in 4 mongrel dogs. Before flap repositioning, a non-resorbable barrier membrane was placed on the buccal defect in the experimental group. No membrane was placed in the control group. In 12 weeks after placement, the dogs were sacrificed and undecalcified histologic specimens were prepared. The vertical distance from the smooth-rough surface interface(SRI) to gingiva, 1st bone contact and bone crest were measured in buccal and lingual side. The horizontal thicknesses of gingiva and bone at 0, 1, 2 and 3mm below SRI were measured. Results: The buccal bone was resorbed more than lingual bone in both groups and there was statistical significance(p<0.05). The distances from SRI to 1st bone contact were $2.45{\pm}2.35\;mm$ in experimental group and $4.49{\pm}3.10\;mm$ in control group. In all vertical level, lingual bone was thicker than buccal bone(p<0.05). Conclusion: Buccal bone was reduced more than lingual bone in immediate implant placement into periapically infected extraction sockets. Placement of non-resorbable barrier membrane reduced the buccal bone resorption. However there was no statistical significance.