• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.301-308
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• 2007

Purpose: This study was performed to compare and evaluate the effect of recipient site depths and diameters of the drills on the primary stability of implant in pig's ribs. Materials and methods: An intact pig's rib larger than 8 mm in width and 20 mm in height; RBM(resorbable blasting media) surface blasted ${\phi}3.75mm$ and 8.0 mm long USII Osstem Implants (Osstem Co., Korea) were used. To measure the primary stability, $Periotest^{(R)}$ (Simens AG, Germany) and $Osstell^{TM}$ (Model 6 Resonance Frequency Analyser: Integration Diagnostics Ltd., Sweden) were used. They were divided into 6 groups according to its recipient site formation method: D3H3, D3H5, D3H7, D3.3H3, D3.3H5, D3.3H7. Each group had, as indicated, 10 implants placed, and total 60 implants were used. The mean value was obtained by 4-time measurements each on mesial, distal, buccal, and lingual side perpendicular to the long axis of the implant using $Periotest^{(R)}$ and $Osstell^{TM}$. For statistical analysis one-way ANOVA was used to compare the mean value of each group, and the correlation between placement depths and the primary stability, and that of measuring instruments was analyzed using SPSS 12.0. Results: The primary stability of the implants increased as the placement depths increased (p<0.05), and showed a proportional relationship (p<0.01). The primary stability increased when the diameter of the recipient site was smaller than that of the implant but with no statistical significance. There was a strong correlation between $Osstell^{TM}$ and $Periotest^{(R)}$ (p<0.01). Conclusion: These results suggest that increasing the placement depth of implants enhances the primary stability of implant.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.777-788
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• 2005

The primary stability of implants is an important factor to predict the osseointegration. Recently, the resonance frequency analysis has been used to measure the primary stability. It is an objective method to monitor the stability of implants during healing phase. This study is to validate the differences in the effect of the osteotome method according to the bone quality as well the thickness of cortical bone. Two hundred seventy implants of 3.75mm in diameter(Neoplant, Neobiotech, Korea) were placed in 135 bovine ribs. The bone quality is classified into 3 classes according to the number of bone marrow spaces which implants would be placed, and then classified into 9 subclasses after the ribs were trimmed. Two implants were placed in 15 specimens of each class. The conclusion were as follows: 1. In case of less dense cancellous bone, the oseotome method is more effective in primary stability rather than the drilling method(p <0.05). 2. If there was cortical bone, it is more advantagous to get stronger primary stability. 3. If cancellous bone is more dense or if cortical bone exists, there is no statistical significance between drilling and osteotome method(p <0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.248-257
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• 2005

Statement of problem. Cortical bone plays an important role in the primary implant stability, which is essential to immediate/early loading. However, immediate load-bearing capacity and primary implant stability according to the change of the cortical bone thickness have not been reported. Purpose. The objectives of this study were (1) to measure the immediate load-bearing capacity of implant and primary implant stability according to the change of cortical bone thickness, and (2) to evaluate the correlation between them. Material and methods.48, screw-shaped implants (3.75 mm$\times$7 mm) were placed into bovine rib bone blocks with different upper cortical bone thickness (0-2.5 mm) and resonance frequency (RF) values were measured subsequently. After fastening of healing abutment. implants were subjected to a compressive load until tolerated micromotion threshold known for the osseointegration and load values at threshold were recorded. Thereafter, RF measurement after loading, CT taking and image analysis were performed serially to evaluate the cortical bone quality and quantity. Immediate load-bearing capacity and RF values were analyzed statistically with ANOVA and post-hoc method at 95% confidence level (P<0.05). Regression analysis and correlation test were also performed. Results. Existence and increase of cortical bone thickness increased the immediate load-bearing capacity and RF value (P<0.05) With the result of regression analysis, all parameter's of cortical bone thickness to immediate load-bearing capacity and resonance frequency showed significant positive values (P<0.0001). A significant high correlation was observed between the cortical bone thickness and immediate load-beating capacity (r=0.706, P<0.0001), between the cortical bone thickness and resonance frequency (r=0.753, P<0.0001) and between the immediate load-bearing capacity and resonance frequency (r=0.755, P<0.0001). Conclusion. In summary, cortical bone thickness change affected the immediate load-baring capacity and the RF value. Although RF analysis (RFA) is based on the measurement of implant/bone interfacial stiffness, when the implant is inserted stably, RFA is also considered to reflect implant/bone interfacial strength of immediately after placement from high correlation with the immediate load-baring capacity. RFA and measuring the cortical bone thickness with X-ray before and during surgery could be an effective diagnosis tool for the success of immediate loading of implant.

• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.10-15
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• 2011

PURPOSE. This study investigated the influence of bone quality and surgical technique on the implant stability quotient (ISQ) value. In addition, the influence of interfacial bone quality, directly surrounding the implant fixture, on the resonance frequency of the structure was also evaluated by the finite element analysis. MATERIALS AND METHODS. Two different types of bone (type 1 and type 2) were extracted and trimmed from pig rib bone. In each type of bone, the same implants were installed in three different ways: (1) Compaction, (2) Self-tapping, and (3) Tapping. The ISQ value was measured and analyzed to evaluate the influence of bone quality and surgical technique on the implant primary stability. For finite element analysis, a three dimensional implant fixture-bone structure was designed and the fundamental resonance frequency of the structure was measured with three different density of interfacial bone surrounding the implant fixture. RESULTS. In each group, the ISQ values were higher in type 1 bone than those in type 2 bone. Among three different insertion methods, the Tapping group showed the lowest ISQ value in both type 1 and type 2 bones. In both bone types, the Compaction groups showed slightly higher mean ISQ values than the Self-tapping groups, but the differences were not statistically significant. Increased interfacial bone density raised the resonance frequency value in the finite element analysis. CONCLUSION. Both bone quality and surgical technique have influence on the implant primary stability, and resonance frequency has a positive relation with the density of implant fixture-surrounding bone.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.30.1-30.6
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• 2016

Background: The prognosis of wide implants tends to be controversial. While wider implants were initially expected to result in a larger osseointegration area and have higher levels of primary stability, they were reported to have a relatively high rate of failure. The clinical outcome of ultrawide implants of more than 6 mm in diameter was evaluated through a retrospective study. Methods: The investigation was conducted on patients who had received ultrawide implant (${\geq}6mm$ diameter) placements in Seoul National University Bundang Hospital from January 2008 to December 2013. Complications were investigated during the maintenance period, and marginal bone loss was measured using periapical radiography. Primary stability immediately after the implant placement and second stability after second surgery or during impression were measured using $Osstell^{(R)}$ Mentor (Osstell, Sweden) as an implant stability quotient (ISQ). Results: Fifty-eight implants were placed in 53 patients (30 male, 23 female), and they were observed for an average of $50.06{\pm}23.49$ months. The average ISQ value increased from $71.22{\pm}10.26$ to $77.48{\pm}8.98$ (P < 0.005). The primary and secondary stability shows significantly higher at the mandible than at the maxilla (P < 0.001). However, mean survival rate shows 98.28 %. Average marginal bone loss of 0.018 and 0.045 mm were measured at 12 and 24 months after the loading and 0.14 mm at final follow-up date (mean 46.25 months), respectively. Also in this study, the bone loss amount was noticeably small compared to regular implants reported in previous studies. Conclusions: The excellent clinical outcome of ultrawide implants was confirmed. It was determined that an ultrawide implant can be used as an alternative when the bone quality in the posterior teeth is relatively low or when a previous implant has failed.

• Journal of Periodontal and Implant Science
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• v.40 no.1
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• pp.19-24
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• 2010

Purpose: It has been suggested that primary implant stability plays an essential role in successful osseointegration. Resonance frequency analysis (RFA) is widely used to measure the initial stability of implants because it provides superior reproducibility and non-invasiveness. The purpose of this study is to investigate whether the fractal dimension from the panoramic radiograph is related to the primary stability of the implant as represented by RFA. Methods: This study included 22 patients who underwent dental implant installation at the Department of Periodontology of Seoul National University Dental Hospital. Morphometric analysis and fractal analysis of the bone trabecular pattern were performed using panoramic radiographs, and the implant stability quotient (ISQ) values were measured after implant installation using RFA. The radiographs of 52 implant sites were analyzed, and the ISQ values were compared with the results from the morphometric analysis and fractal analysis. Results: The Pearson correlation showed a linear correlation between the ISQ values of RFA and the parameters of morphometric analysis but not of statistical significance. The fractal dimension had a linear correlation that was statistically significant. The correlation was more pronounced in the mandible. Conclusions: In conclusion, we suggest that the fractal dimension acquired from the panoramic radiograph may be a useful predictor of the initial stability of dental implants.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.547-554
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• 2014

Implant success is achieved by the synergistic combination of numerous biomechanical factors. This report examines the mechanical aspect of implants. In particular, it is focused on macrodesign such as thread shape, pitch, width and depth, and crestal module of implants. This study reviews the literature regarding the effect of implant thread geometry on primary stability and osseointegration under immediate loading. The search strategy included both in vitro and in vivo studies published in the MEDLINE database from January 2000 to June 2014. Various geometrical parameters are analyzed to evaluate their significance for optimal stress distribution, implant surface area, and bone remodeling responses during the process of osseointegration.

• Journal of Korean Dental Science
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• v.3 no.1
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• pp.11-16
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• 2010

Objective : This prospective study sought to verify the stability of three types of short implants measuring 7mm or less. Materials and methods : Implants measuring 7mm or less were placed in patients at multicenter dental clinics in Korea, China, Taiwan, and Singapore. Initial stability, intraoperative and postoperative complications, crestal bone loss, and survival rate of the implant were prospectively evaluated. Results : The primary stability of a 6-mm implant was lower than that of a 7-mm implant. The marginal bone loss of short implants measuring less than 7mm was minimal. Complications such as wound dehiscence, implant mobility, and peri-implant mucositis developed, and these were associated with initial implant failure. The short-term survival rate of 6-mm implant was 93.7%, and that of 7-mm implant, 96.6%. Conclusion : Short implant for the mandible with insufficient height for the residual ridge can be selectively used. Poor primary stability and wound dehiscence can cause osseointegration failure and alveolar bone loss.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.4
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• pp.469-481
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• 2007

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.80-88
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• 2018

Purpose: Implant surface modification and implant design are the principle targets for achieving successful primary stability. The aim of this study was to measure implant stability quotient (ISQ) values of sandblasted, large-grit, acid-etched (SLA) implants with tapered straight body design during the healing period, and to determine the various factors affecting implant stability. Materials and Methods: To measure implant stability, resonance frequency analysis (RFA) was performed in 26 patients (13 women and 13 men) with 44 SLA implants with tapered straight body design. Implant stability (ISQ values) was evaluated at baseline and healing abutment connection (12 weeks), and the correlations between RFA and insertion torque (IT), bone quality, and jawbone were determined. Results: The mean ISQ value of the implants was $69.4{\pm}10.2$ at the time of implant placement (baseline) and $81.4{\pm}6.9$ at the time of healing abutment connection (P < 0.05). Significant differences were found between RFA and bone quality and between RFA and jawbone (P < 0.05). No significant differences were found between RFA and IT, insertion area, fixture diameter, and implant length (P > 0.05). Conclusion: ISQ values of SLA implants with tapered straight body design were high at baseline and healing abutment connection. It was concluded that SLA implants with tapered straight body design show improved primary and secondary stability, and that immediate or early loading may be applicable.