• 대한치과보철학회지
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• 제47권3호
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• pp.335-341
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• 2009

연구목적: 충분한 골질과 골량은 임플란트의 조기 실패 방지와 초기 안정성을 위해서 중요한 사항으로 알려져 있다. 임플란트 길이나 직경이 초기 안정성에 미치는 영향을 연구한 다수의 실험들이 골과의 접촉면적을 달리하였기 때문에 직경과 길이만이 초기 안정성에 미치는 실제 영향을 파악하는데 한계가 있다. 이에 유사한 표면적을 가지는 임플란트를 통하여 길이와 직경 상대적 변화가 초기 안정성에 미치는 영향을 알아보고자 하였다. 연구 재료 및 방법: 골질에 따라 피질골과 해면골의 두께가 다른 4종류의 폴리우레탄 모형골을 임플란트 식립에 사용하였다. 유사한 표면적과 형태를 가지나 직경과 길이가 서로 다른 임플란트 ($3.5{\times}13.0\;mm$, $4.0{\times}11.5\;mm$, $4.5{\times}10.0\;mm$, $5.0{\times}8.5\;mm$) 10개를 식립하고 식립 회전력과 공진 주파수를 측정하였다. 결과 및 결론: 초기 안정성에 영향을 미치는 주 요소는 골질이었으며 (P < .05), 식립 회전력과 공진 주파수 모두 골질이 우수할수록 높은 측정치를 보였다. 2. D1, D2, D3 모형골에서 임플란트의 직경이 커지고 길이가 짧아짐에 따라 공진 주파수는 유의한 차이를 보이지 않았으나 (P >.05), 식립 회전력은 증가하였다 (P <.05). 3. D4 모형골에서는 임플란트의 직경이 커지고 길이가 짧아짐에 따라 공진주파수와 식립 회전력 모두 감소하였다 (P <.05). 이상의 결과로부터 골질이 양호한 조건에서는 길이가 짧더라도 직경이 큰 임플란트의 사용이 초기 안정성 측면에서 부가적 수술의 대안이 될 수 있을 것으로 생각된다.

• Journal of Korean Dental Science
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• 제4권2호
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• pp.67-72
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• 2011

Purpose: This study sought to evaluate the effects of bone graft wedging on the initial stability of implants in bone sites of unfavorable quality. Materials and Methods: Three male beagle dogs were used in this study. Osteotomies were performed with parallel drills (${\O}4.1{\times}10mm$), and fixtures (${\O}3.3{\times}8mm$) were placed. The control group was given implants without bone graft. Experiment group A was given implants with minimal initial stability using autobone grafts, whereas experiment group B was given xenografts. Groups were also divided by healing times at 4, 8, and 12 weeks. Results: All implants in the control group failed to osseointegrate. On the other hand, all implants in the experiment groups were clinically well-maintained during the entire experiment period. After 4, 8, and 12 weeks, bone-to-implant contact (BIC) ratio and implant stability quotient (ISQ) increased in the experiment groups. The differences between experiment groups A and B were not statistically significant, however. Conclusion: In unfavorable bone regions for dental implants, bone graft packing into the osteotomy prior to implant placement secured minimal initial stability and showed reasonable BIC ratios and ISQ values throughout the study period.

• Journal of Periodontal and Implant Science
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• 제40권5호
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• pp.239-243
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• 2010

Purpose: The purpose of this study was to evaluate the effects of implant shape and bone preparation on the primary stability of the implants using resonance frequency analysis. Methods: Sixty bovine rib blocks were used for soft and hard bone models. Each rib block received two types of dental implant fixtures; a straight-screw type and tapered-screw type. Final drilling was done at three different depths for each implant type; 1 mm under-preparation, standard preparation, and 1 mm over-preparation. Immediately after fixture insertion, the implant stability quotient (ISQ) was measured for each implant. Results: Regardless of the bone type, the ISQ values of the straight-screw type and tapered-screw type implants were not significantly different (P>0.05). Depth of bone preparation had no significant effect on the ISQ value of straight-screw type implants (P>0.05). For the tapered-screw type implants, under-preparation significantly increased the ISQ value (P<0.05), whereas overpreparation significantly decreased the ISQ value (P<0.05). Conclusions: Within the limitations of this study, it is concluded that bone density seemed to have a prevailing effect over implant shape on primary stability. The primary stability of the tapered-screw type implants might be enhanced by delicate surgical techniques.

• Journal of Periodontal and Implant Science
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• 제48권6호
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• pp.360-372
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• 2018

Purpose: It has been suggested that resonance frequency analysis (RFA) can measure changes in the stability of dental implants during osseointegration. This retrospective study aimed to evaluate dental implant stability at the time of surgery (primary stability; PS) and secondary stability (SS) after ossseointegration using RFA, and to investigate the relationship between implant stability and cortical bone thickness. Methods: In total, 113 patients who attended the Tohoku University Hospital Dental Implant Center were included in this study. A total of 229 implants were placed in either the mandibular region (n=118) or the maxilla region (n=111), with bone augmentation procedures used in some cases. RFA was performed in 3 directions, and the lowest value was recorded. The preoperative thickness of cortical bone at the site of implant insertion was measured digitally using computed tomography, excluding cases of bone grafts and immediate implant placements. Results: The mean implant stability quotient (ISQ) was $69.34{\pm}9.43$ for PS and $75.99{\pm}6.23$ for SS. The mandibular group had significantly higher mean ISQ values than the maxillary group for both PS and SS (P<0.01). A significant difference was found in the mean ISQ values for PS between 1-stage and 2-stage surgery (P<0.5). The mean ISQ values in the non-augmentation group were higher than in the augmentation group for both PS and SS (P<0.01). A weak positive correlation was observed between cortical bone thickness and implant stability for both PS and SS in all cases (P<0.01). Conclusions: Based on the present study, the ISQ may be affected by implant position site, the use of a bone graft, and cortical bone thickness before implant therapy.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.2.1-2.6
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• 2017

Background: All clinicians are aware of the difficulty of installing a dental implant in posterior maxilla because of proximate position of maxillary sinus, insufficient bone width, and lower bone density. This study is to examine which factors will make the implantation in the posterior maxilla more difficult, and which factors will affect the postoperative implant stability in this region. Methods: Five hundred seventy-three fixtures on the maxilla posterior were included for this study from all the patients who underwent an installation of the dental implant fixture from January 2010 to December 2014 at the Department of Oral and Maxillofacial Surgery in Pusan National University Dental Hospital (Yangsan, Korea). The postoperative implant stability quotient (ISQ) value, fixture diameter and length, presence of either bone graft or sinus lift, and graft material were included in the reviewed factors. The width and height of the bone bed was assessed via preoperative cone beam CT image analysis. The postoperative ISQ value was taken just before loading by using the OsstellTM $mentor^{(R)}$ (Integration Diagnostics AB, Gothenburg, Sweden). The t test and ANOVA methods were used in the statistical analysis of the data. Results: Mean ISQ of all the included data was 79.22. Higher initial bone height, larger fixture diameter, and longer fixture length were factors that influence the implant stability on the posterior edentulous maxilla. On the other hand, the initial bone width, bone graft and sinus elevation procedure, graft material, and approach method for sinus elevation showed no significant impact associated with the implant stability on the posterior edentulous maxilla. Conclusions: It is recommended to install the fixtures accurately in a larger diameter and longer length by performing bone graft and sinus elevation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.518-528
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• 2008

Purpose: The long-term experience of using osseointegrated implants for prosthetic rehabilitation of the edentulous patients shows that high success rates can be predictably achieved. Primary implant stability has been identified to be a prerequisite to achieve osseointegration. In this study, we set up the amount of removed bone so that it differed on implant installation site for each group. The influence of each initial stability on secondary stability and osseointegration was compared with time lapse using resonance frequency analysis and histomorphometric analysis. Materials and methods: A total 27 US $II^{(R)}$ (Osstem, Korea) implants were placed in the mandibular edentulous area of 3 beagle dogs. The implant site was prepared by the conventional technique with drills, and three experimental groups were divided into under-drilling group, normal-drilling group and over-drilling group. The Implant Stability Quotient (ISQ) was measured at intervals of immediately, 4, 8, 12 weeks after placement using $Osstell^{(R)}$ mentor RFA. After the animals were sacrificed, histomorphometric evaluation was executed for measuring BIC and BD. Results: 1) The under-drilled group showed most high ISQ value for whole experiment period. 2) Bone-to-implant-contact(BIC) showed the tendency to be increased gradually as the experiment period passed except the 8 weeks of the normal group. 3) The under-drilled group showed most high bone density(BD) level for whole experiment period, and it was expressed the aspect to be increased gradually according to an experiment period passage in the average of all group. 4) Resonance frequency analysis and histomorphometric analysis are presumed by generally proportional. Conclusions: As this research result, it seems that there are some correlation between resonance frequency analysis and histomorphometric analysis. As are accomplished osseointegration stably so that more superior at the region which the overpressure comes to add, it will be applicable method in clinical field.

• 구강회복응용과학지
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• 제34권1호
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• pp.32-38
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• 2018

목적: 3.6 mm 이하 좁은 직경 임플란트의 일정 기간 생존율을 초기고정 값과 방사선학적 계측을 통해 분석해보고자 하였다. 연구 재료 및 방법: 24명의 환자에 식립된 직경 3.6 mm 이하, 길이 7 mm 이상의 38개의 임플란트를 조사하였다. 식립된 임플란트의 platform 직경, body 직경, 길이, 식립 부위 등을 확인하였고 식립 시 골유도재생술의 동반 시행 여부, 완성된 보철의 형태를 확인하였다. 초기고정 값은 임플란트 식립 직후 측정한 implant stability quotient (ISQ) 값을 확인하였고, 방사선 사진을 통해 식립된 임플란트의 근 원심 marginal bone level (MBL)을 측정하였다. 결과: 전체 임플란트의 생존율은 92.11% 이었고 ISQ값은 평균 66.26으로 나타났다. 생존한 임플란트의 MBL 변화는 평균 $0.14{\pm}0.31mm$를 나타내었다. Platform 직경이 body 직경보다 큰 임플란트 중 실패한 임플란트는 없었다. 결론: 좁은 직경의 임플란트는 좁은 직경의 치조제에 안정적인 치료 결과를 나타낸다 사료된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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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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• 제50권1호
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• pp.56-66
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• 2020

Purpose: A stability-measuring device that utilizes damping capacity analysis (DCA) has recently been introduced in the field of dental implantology. This study aimed to evaluate the sensitivity and reliability of this device by measuring the implant stability of ex vivo samples in comparison with a resonance frequency analysis (RFA) device. Methods: Six implant beds were prepared in porcine ribs using 3 different drilling protocols to simulate various implant stability conditions. Thirty-six pork ribs and 216 bone-level implants measuring 10 mm in height were used. The implant beds were prepared using 1 of the following 3 drilling protocols: 10-mm drilling depth with a 3.5-mm-diameter twist drill, 5-mm drilling depth with a 4.0-mm-diameter twist drill, and 10-mm drilling depth with a 4.0-mm-diameter twist drill. The first 108 implants were external-connection implants 4.0 mm in diameter, while the other 108 implants were internal-connection implants 4.3 mm in diameter. The peak insertion torque (PIT) during implant placement, the stability values obtained with DCA and RFA devices after implant placement, and the peak removal torque (PRT) during implant removal were measured. Results: The intraclass correlation coefficients (ICCs) of the implant stability quotient (ISQ) results obtained using the RFA device at the medial, distal, ventral, and dorsal points were 0.997, 0.994, 0.994, and 0.998, respectively. The ICCs of the implant stability test (IST) results obtained using the DCA device at the corresponding locations were 0.972, 0.975, 0.974, and 0.976, respectively. Logarithmic relationships between PIT and IST, PIT and ISQ, PRT and IST, and PRT and ISQ were observed. The mean absolute difference between the ISQ and IST values on a Bland-Altman plot was -6.76 (-25.05 to 11.53, P<0.05). Conclusions: Within the limits of ex vivo studies, measurements made using the RFA and DCA devices were found to be correlated under a variety of stability conditions.

• 구강회복응용과학지
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• 제30권3호
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• pp.253-258
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• 2014

본 증례는 상악 구치부에서 실패한 임플란트 제거 후 깊은 나사선을 갖는 직경이 큰 임플란트를 식립 후 조기하중을 가한 증례이다. 1년 경과 후, 임플란트 안정성 지수에서 안정적인 결과를 보였다. 본 임상증례는 상악 구치부에서 깊은 나사선을 갖는 임플란트를 이용한 조기하중의 가능성을 보여준다.