• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.8.1-8.6
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• 2018

Background: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. Methods: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. Results: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. Conclusions: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.187-197
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• 2005

The aim of this study was to investigate the influence of peri-implant soft tissue and bone thickness on the early dimensional change of peri-implant soft tissue. Seventy-seven non-submerged implants of 39 patients which had been loaded more than 6 months were selected for the study. Following clinical parameters were measured; bucco-lingual bone width of the alveolar bone for implant placement before implant surgery; distance between implant shoulder and the first bone/implant contact at the surgery; presence of plaque, probing depth, bleeding on probing, width of keratinized mucosa, mucosa thickness, distance between implant shoulder and peri-implant mucosa, crown margin location at follow-up examination. The results showed that distance between implant shoulder and peri-implant mucosa (DIM) was correlated with probing depth and width of keratinized mucosa (p < 0.05). In addition, mucosa thickness was also correlated with probing depth (p<0.05). However, the bone width of alveolar bone and soft tissue thickness were not found to be correlated with DIM. It is important to understand the meaning of peri-implant tissue dimension in relation to dimensional changes of peri-implant soft tissue which designates appearance of implant-supported restorations. Future study is needed to elucidate the significance of the buccal bone thickness and soft tissue thickness with respect to the change of peri-implant soft tissue margin with the use of an instrument capable of measuring buccal bone thickness directly.

• 대한치과보철학회지
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• 제43권6호
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• pp.736-744
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• 2005

Statement of problem. Initial stability of implant is an important factor for predicting osseointegration. It requires a rapid, non-invasive, user-friendly technique to frequently assess the implant stability and the degree of osseointegration. Purpose. The aim of this study was to evaluate the correlation between the resonance frequency analysis (RFA) and the radiographic method for peri-implant bone change under in vitro conditions. Material and Method. Twenty implants of 3.75 mm in diameter(Neoplant, Neobiotech, Korea) were used. To simulate peri-implant bone change, 2 mm-deep $45^{\circ}$ range horizontal defect and 2 mm-deep $90^{\circ}$ range horizontal defect area were serially prepared perpendicular to the X-ray beam after conventional implant insertion. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of implants and direct digital image was obtained. ISQ values and gray values inside threads were measured before and after peri-implant bone defect preparation. Results. Within a limitation of this study, ISQ value of resonance frequency analysis was changed according to peri-implant bone change (p<0.05) and gray value of radiographic method was changed according to peri-implant bone change (p<0.05). There was no correlation between the ISQ value and the gray value for peri-implant bone change (p>0.05). But, in horizontal defect condition, relatively positive correlation were between ISQ and gray values(r=0.663). Conclusion. This results provided a possibility that peri-implant bone change may be evaluated by both RFA and radiographic method.

• 대한치과보철학회지
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• 제39권3호
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• pp.273-281
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• 2001

Digital subtraction radiography may be one of the most precise and noninvasive methods for assessing subtle density changes in peri-implant bone, providing additional diagnostic information on implant tissue integration in overall maintenance. The aims of this study were to evaluate density changes after first, second surgery of dental implant and to measure the amount of marginal bone loss 9 months after second surgery using digital subtraction radiography. Bone change around 30 screw-shaped implants in 16 patients were assessed on radiographs. 17 Branemark implants of 3.75mm in diameter(Nobel Biocare, Goteborg, Sweden), 2 Branemark implants of 5.0mm in diameter, 11 $Replace^{TM}$ implants of 4.3mm in diameter(Nobel Biocare, Goteborg, Sweden) were used. To standardize the projection geometry of serial radiographs of implants, customized bite block was fabricated using XCP film holder(Rinn Corporation, Elgin, IL.) with polyether impression material of Impregum(ESPE, Germany) and direct digital image was obtained. Qualitative and quantitative changes on radiographs were measured with Emago software(The Oral Diagnostic System, Amsterdam, Netherlands). The results were as follows: 1. The peri-implant bone density of 69.2% implants did not change and the peri-implant bone density of 30.8% implants decreased after 3 months following first surgery. 2. The crestal bone density of 53.9% implants decreased first 3 months after second surgery. The crestal bone density of 58.8% implants increased 9 months after second surgery. No density change was observed around the midportion of the implants after second surgery, 3. The amount of marginal bone loss between different kinds of implants showed no statistically significant differences (p>0.05). 4. More than 90% of total marginal bone loss recorded in a 9-month period occurred during the first 3 months.

• Journal of Periodontal and Implant Science
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• 제43권2호
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• pp.58-63
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• 2013

Purpose: The aim of this study was to measure the peri-implant bone length surrounding implants that penetrate the sinus membrane at the posterior maxilla and to evaluate the survival rate of these implants. Methods: Treatment records and orthopantomographs of 39 patients were reviewed and analyzed. The patients had partial edentulism at the posterior maxilla and limited vertical bone height below the maxillary sinus. Implants were inserted into the posterior maxilla, penetrating the sinus membrane. Four months after implant insertion, provisional resin restorations were temporarily cemented to the abutments and used for one month. Then, a final impression was taken at the abutment level, and final cement-retained restorations were delivered with mutually protected occlusion. The complications from the implant surgery were examined, the number of failed implants was counted, and the survival rate was calculated. The periimplant bone lengths were measured using radiographs. The changes in initial and final peri-implant bone lengths were statistically analyzed. Results: Nasal bleeding occurred after implant surgery in three patients. No other complications were found. There were no failures of the investigated implants, resulting in a survival rate of 100%. Significantly more bone gain around the implants (estimated difference=-0.6 mm, P=0.025) occurred when the initial residual bone height was less than 5 mm compared to the >5 mm groups. No significant change in peri-implant bone length was detected when the initial residual bone height was 5 mm or larger. Conclusions: This study suggests that implants penetrating the sinus membrane at the posterior maxilla in patients with limited vertical bone height may be safe and functional.

• 대한치과의사협회지
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• 제54권4호
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• pp.258-273
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• 2016

In spite of appropriate treatment of peri-implantitis, the peri-implant bone loss was keep going, the clinician should remove the osseointegrated implant. the conventional methods are like a extraction of natural teeth, and use of trephine drills. In these days, many exclusive instruments are invented by implant companies. these instruments can make easy, least invasive, less traumatic removal of osseointegrated implants. In generally peri-implant bone loss progress steadily less sign and symptoms that the patient do not want to remove their implants. However, the failure of dental implant is big burden to clinicians and also patients. In the dental implant treatment, there is no 'failure' but only is 'replacement' or 'change'.

• Journal of Periodontal and Implant Science
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• 제52권3호
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• pp.194-205
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• 2022

Purpose: This study aimed to determine the long-term outcomes after peri-implantitis treatment and the factors affecting these outcomes. Methods: This study included 92 implants in 45 patients who had been treated for peri-implantitis. Clinical data on the characteristics of patients and their implants were collected retrospectively. The change in the marginal bone level was calculated by comparing the baseline and the most recently obtained (≥3 years after treatment) radiographs. The primary outcome variable was progression of the disease after the treatment at the implant level, which was defined as further bone loss of >1.0 mm or implant removal. A 2-level binary logistic regression analysis was used to identify the effects of possible factors on the primary outcome. Results: The mean age of the patients was 58.7 years (range, 22-79 years). Progression of peri-implantitis was observed in 64.4% of patients and 63.0% of implants during an observation period of 6.4±2.7 years (mean±standard deviation). Multivariable regression analysis revealed that full compliance to recall visits (P=0.019), smoking (P=0.023), placement of 4 or more implants (P=0.022), and marginal bone loss ≥4 mm at baseline (P=0.027) significantly influenced the treatment outcome. Conclusions: The long-term results of peri-implantitis treatment can be improved by full compliance on the part of patients, whereas it is impaired by smoking, placement of multiple implants, and severe bone loss at baseline. Encouraging patients to stop smoking and to receive supportive care is recommended before treatment.

• Journal of Periodontal and Implant Science
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• 제48권5호
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• pp.326-333
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• 2018

Purpose: The present study investigated the outcomes of a newly-developed, simple, and practical nonsurgical treatment modality suitable for most forms of intrabony defects around failing dental implants using intrasulcular delivery of chlorhexidine solution and minocycline hydrochloride (HCl). Methods: Forty-five dental implants in 20 patients diagnosed with peri-implantitis were included. At baseline and the study endpoint, the probing pocket depth (PPD), clinical attachment level (CAL), and the presence of bleeding on probing (BOP) at 6 sites around each implant were recorded. The radiographic osseous defect morphology at the mesial or distal proximal aspect of each implant was classified as 1) narrow or wide and 2) shallow or deep. For a comparative analysis of bone changes according to the defect morphology, the distance from the implant shoulder to the most coronal bone-to-implant contact point (DIB) at the mesial and distal aspects of each implant was measured at baseline and the endpoint. Patients were scheduled to visit the clinic every 2-4 weeks for intrasulcular irrigation of chlorhexidine and delivery of minocycline HCl. Results: We observed statistically significant decreases in PPD, CAL, and BOP after treatment. At the endpoint, bone levels increased in all defects, regardless of the osseous morphology of the intrabony defect. The mean DIB change in deep defects was significantly greater than that in shallow defects. Although the mean bone gain in narrow defects was greater than in wide defects, the difference was not statistically significant. Conclusions: We propose that significant and sustainable improvements in both clinical and radiographic parameters can be expected when intrabony defects around dental implants are managed through a simple nonsurgical approach involving combined intrasulcular chlorhexidine irrigation and local delivery of minocycline HCl.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.53-63
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• 2005

Number of fixtures supporting prosthesis for rehabilitation of partial edentulism in distal area is an important factor in distal area to the bone tissue response around dental implant. Optimal number and optimal positioning of dental implant has leaded to the stable condition of bone tissue and successful long-term treatment outcome. This clinical and radiographic study was performed to document and evaluate the short-term result of occlusal rehabilitation by means of implant-supported fixed prostheses (ISPs) especially for partial edentulism in distal area in patients treated for advanced periodontal disease and to verify the number of fixture affecting the bone tissue response. A total of 30 consecutive patients referred because of advanced periodontal disease were included. Before the implant therapy was initiated, periodontal treatment was performed and the outcome evaluated during at least a 6-month period. An individual maintenance care program was designed for each patient. All 75 implants were placed using a 2-stage surgical approach. The patients were divided into 2 groups, in one of which two fixtures were placed and in the other of which three fixtures were placed with tripodal geometry. Following installation of the ISPs, all patients underwent a baseline examination including evaluation of i) oral hygiene, and ii) periodontal/ peri-implant conditions, and iii) radiographs. These examinations were repeated annually during the 1 or 2-year observation period. The results were as follows: 1.No single implant was lost during the observation follow-up period. 1.The percentage of plaque harboring surfaces and bleeding units upon probing were found to be low (<10%), and no soft tissue complications were recorded. 1.Two-fixture group showed bone destruction ranged from 0.0mm to 1.5mm and the mean was 0.31mm. Three-fixture group showed more bone destruction of 0.51mm. There was no statistically difference between two groups. These results suggested that the factor for success is not the number of fixture but the strict maintenance of peri-implant tissue health and initial stability of fixture.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.137-150
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• 2007

CADIA(Computer-assisted densitometric image analysis) method is used to analyze bone density changes around the implants. The usefullness and reproducibility of the method was assessed. We tried to find out if there is any possibility to quantitiate and qualitify peri-implant bone density change as time passes. And we concluded that this newly developed linear analysis is efficient for analyzing peri-implant bone density change non-Invasively. In this study, 2152 machined $Br{\aa}nemark$ fixtures installed from 1994 to 2002 in the department of Periodontics, Dental hospital of College of Dentistry, Yonsei University were included. Of these fixtures 22 radiographically analyzable failed fixtures were used as experimental group, and 22 successful implants placed in the same patient were used as control group. 1. 57 out of 1635 machined $Br{\aa}nemark$ standard and Mk II implants system failed, the survival rate was 96.5%. And 11 out of 517 machined $Br{\aa}nemark$ Mk III and Mk IV implants system failed, the survival rate was 97.9%. Total survival rate was 96.8%. 2. 22 failed implants were used for the analysis, 10 of which failed before prosthetic treatment due to infection and overheating. 12 failed due to overload after prosthetic treatment, 63.6% of which failed during the early phase of functional loading, i, e. before 1 year of loading. 3. Bone density change values around coronal region of the failed implants were $-6.54{\pm}6.35$, middle region were $-3.53{\pm}5.78$, apical region were $-0.75{\pm}10.33$, resulting in average of $-3.71{\pm}8.03$. 4. Bone density change values around coronal region of the successful implants were $4.25{\pm}4.66$, middle region were $6.33{\pm}5.02$, apical region were $9.89{\pm}4.67$, resulting in average of $6.27{\pm}5.29$. 5. There was a statistically significant difference between two groups (p<0.01). In conclusion, the linear analysis method using computer-assisted densitometric image analysis could be a useful method for the analysis of implants, and could be used for future implant researchs.