• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.533-542
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• 2003

The purpose of this study is to evaluate histologic result of bone substituting material on defects followed tooth extraction. We compare the histologic findings control, DFDBA, Bio-Oss(R), and $Regenafil^{TM}$, Briefly, mandibular premolar teeth were extracted available for bone filling. All alveolar sites were checked after extraction and thoroughly debrided with a dental curet to remove the periodontal ligament. Extraction sites were prepared dehiscence on buccal side 7mm height from alveolar crest. The graft materials were filled into the extraction socket and dehiscenc defects. The animals were sacrificed 12 weeks after implantation. Both treated and control mandibular sites were histologically evaluated with light microscopy. Histologic observation at 12 weeks revealed that control and experimental sites were healed uneventfully and directly apposed to new bone without any adverse tissue reaction. DFDBA and Bio-Ossn(R)sites maintain width of alveolar crest but were not fully resorbed. $Regenafil^{TM}$ sites also maintain width and particles were resorbed more than other graft materials. From this results, it was suggested that $Regenafil^{TM}$ is promising boen substituting materials maintaining the width of alveolar crest and height follewed tooth extraction.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.543-551
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• 2007

When clinicians faced with an insufficient volume of supporting bone on ideally esthetic and bio-mechanical position for dental implantation, guided bone regeneration(GBR) was indicated. Although GBR has wide application at clinic, proper time of membrane removal remains qustionable in using non-resorbable membrane, such as non-expanded polytetrafluoroethylene(PTFE), The aim of this study was to compare the effect of maintenance period of PTFE membrane on bone regeneration in rabbit calvarial defects. Eight adult New Zealand white female rabbits were used in this study. Four defects were surgically made in their calvaria. Using a trephine bur, 4 'through and through' defects were created and classified into 3 groups, which were consisted of control group(no graft), experimental group 1(autogenous bone)and experimental group 2(deproteinized bovine bone; $OCS-B^{(R)}$). The defects were covered with PTFE membrane($Cytoplast^{(R)}$). Membranes were removed after 1, 2, 4 and 8 weeks post-GBR procedure in 2 rabbits repectively, All rabbits were sacrificed after 8 week post-GBR procedure. Specimens were harvested and observed histologically. The results were as follow; 1) The use of graft material and membrane was necessary in GBR procedure. 2) When PTFE membranes were removed early, the most favorable bone regeneration was revealed in experimental group T, followed by experimental group II and control group. 3) On GBR, it is recommended that membrane should maintain for 4 weeks with autogenous graft. As well, the use of xenograft need longer maintenance period than autogenous bone. Further evaluations will be needed, such as histomorphologic research, more species and different kinds of graft materials. And on the basis of these studies, clinical researches would be required.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.517-538
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• 1995

Dental implantation is a method restoring missing teeth, especially in the case of severely resorbed edentulous patient. But the direct contact between bone and implant surface, induces stress concentration to the bone and eventually becomes a cause. The purpose of this study was to compare the stress distribution patterns between following two cylindrical implant models. One group has implant apex located in the inferior cortical bone and the other in the cancellous bone. Anterior edentulous mandible was modeled with two dimensional 953,878 nodes, 995,918 elements and compared the deflection and stress distribution under the 70 N,4 load cases for 26 models having variant mandibular height and length. The result were as follows; 1. The stress concentration was more affected by the height of the mandible than implant length. 2. Bicortication mitigates the stress of upper cortical and cancellous bone area at the same height of the mandible 3. Perforation of the inferior mandibular cortex significant stress concentration. 4. Stud type porstheses induced less stress concentration to the cortical and cancellous bone than bar type prostheses. 5. Stress of implant apex for stud type was larger than that of bar type.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.384-390
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• 2018

Hybrid telescopic double crown have ever been good treatment option for patient with periodontally unfavorable few remaining teeth for successful prognosis. Tooth and implant combined telescopic double crown can be used for improving retention and support for denture with strategically placed implants on edentulous ridge. In this case, an 55-year-old female patient had chronic periodontitis with few remaining teeth on maxilla and fixed partial prosthodontics on mandible. Treatment of hybrid telescopic double crown with friction pin lasted 9.5 years only with natural teeth. After 9.5 years, additional implants was installed due to fracture of cast-posted abutment teeth. After implantation, tooth and implant combined double crown had fabricated. Through re-treatment, no complications of new denture has been found during 2 years follow up. This case presents fair prognosis of tooth and implant combined double crown denture in periodontally unfavorable condition.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.98-104
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• 2011

Purpose: The aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmentedsinus using Osteon, a bone graft material, and to assess the height of the grafted material through radiographic evaluation. Methods: Twenty patients were treated with maxillary sinus augmentation and 45 implant fixtures were installed simultaneously or after 6 months healing period. The height of the augmented sinus and the loss of marginal bone were measured by panoramic and intraoral radiographs immediately after augmentation and up to 42 months (mean, 19.4 months) subsequently. Changes in the height of the sinus graft material were calculated radiographically. Results: The cumulative survival rate was 95.56% in all 45 implants. Additionall, normal healing process without any complication was observed in all patients. The original sinus height was mean 4.3 mm and the augmented sinus height was mean 13.4 mm after the surgery. The mean marginal bone loss till 42 months was $0.52{\pm}0.56\;mm$. The reduced height of Osteon was $0.83{\pm}0.38\;mm$ and it did not show significant correlation with the follow up periods (P=0.102). There were no statistically significant differences in reduced height of Osteon according to the simultaneous/delayed implantation (P=0.299) and particle size of Osteon (P=0.644). Conclusions: It can be suggested that Osteon may have predictable result when it was used as a grafting material for sinus floor augmentation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.590-594
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• 2006

Dental implant has become one of the important option for completely or partially edentulous patients, But it is challenging to reconstruct the severely atrophic ridge. Insufficient bone volume could restrict to place the wide and long implant and because of excessive interocclusal clearance, improper prosthetics could be produced. In this case bone augmentation for implant dentistry is necessary procedure to improve the insufficient bone volume. Therefore, bone augmentation or GBR is the most important procedure for successful implant placement and for ideal crown- root ratio. There are various bone augmentation techniques have been introduced recently; like block bone graft, distraction osteogenesis, inlay graft, onlay graft, etc.... In severe bucco-lingual resorption area, ridge splitting is the first choice of the treatment, because it provides a place for implantation and also has compaction effect. This technique may be indicated for sharp mandible and maxillary ridges in patients whose bone quantity is inadequate for primary stabilization. We report that the clinical experience of bone augmentation using ridge splitting technique in bucco-lingual bone resorption area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.428-436
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• 2008

For Longevity of implant, considerations of biomechanical and microbiological aspects must be done. Recently, due to the remarkable development of bone grafting procedure. Implant has been implanted into the more favorable sites but peri-implantitis resulted from periodontal bacteria may obscure the long-term prognosis. Although many different modalities have been introduced to treat the failed implant. Implant's surface and irreversible bony destruction around the implant prevents good result. After Er,Cr:YSGG (waterlase) laser using the wave-length of 2780nm has been introduced to dental field, good results have been reported. Because waterlase uses the hydrokinetic force of water. It is excellent device to detoxify the implant surface mechanically without the heat generation and damage to the implant surface. We designed to evaluate waterlase effect on the peri-implantitis has been occurred after implantation. Four beagle dogs were involved. We have made four premolar extraction in each right and left side of the lower jaw and placed two implants in the anterior of the jaw as a control and six implant were placed posterior in each socket after extraction immediately as an experimental group. We tied floss-silk in each implant to make peri-implantitis intentionally. After three months, we explored peri-implant sites on each experimental fixtures. Using waterlase laser irradiation was performed on that implantitis sites under 3W, air 30% and water 20% intensity for 2 minutes. In control group, we repositioned the flap to cover the exposed fixture without any supportive care. Three months later, we sacrificed experimental animals and extracted and preparated bone blocks with Donath and Breuner (982), Donath (988)'s methods and examined under microscope. We have obtained good re-osseointegration around fixtures after treating with waterlaser irradiation. But it was shown fibroosseointegration in the control group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.340-345
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• 2009

Purpose: The purpose of this study was to evaluate the surgical success of bone reconstruction of the severely atrophic maxilla using autogenous block bone onlay graft from the ramus and ilium prior to dental implantation. And we measured the amount of vertical height change Material and Methods: 26 partially edentulous patients(32 case) who needed block onlay bone graft before implant placement in posterior maxillary area from 2002 to 2009 were selected for this study. Patients consisted of 20 males & 6 females and the average of their age was 54.2. Patients who were treated with ramal bone were 19 case and patients who were treated with iliac bone were 11 case. Digital panoramic X-ray was taken at the day of surgery, 3 months and 6 months later after the surgery. Vertical height change & resorption rate of grafted bone were measured with the same X-rays and compared Results: Two out of 32 bone grafts had to be removed because of inflamation at the grafts area(97.3%). The mean of radiographic vertical height change(change rate) of post-op. 3 month was 0.54mm(8.5%)and 6 month was 0.99mm(15.9%). Compairing to intraoral donor site(ramus), iliac bone had more vertical height change(1.18mm) at 6 month after surgery. Conclusions: Within the limit of this study, autogenous block onlay grafts can be considered a promising treatment for severely atrophic maxilla.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.335-339
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• 2009

The purpose of this study was to evaluate clinical and radiographic changes of regular diameter implants placed in the posterior region. A total of 47 standard diameter implants were consecutively placed in the posterior region of 20 partially edentulous patients. The diameters of the implants were 4.1mm (N=35, 74%) and 4.3mm (N=12, 26%), respectively. Peri-implant bone loss and clinical parameters such as mobility, suppuration, swelling, bleeding on probing (BOP) were evaluated at the baseline and?the final follow-up visit. The age of the patients ranged between 24~82 years (mean age: 54.7 years). The cumulative survival rate of the regular diameter implants loaded for a period of 3-24 months (Mean: $11.7{\pm}7.9$ month) was 100%. The average bone loss over the follow-up was $0.36{\pm}0.67\;mm$. Success rate was 95.7%. Only two implants failed (bone loss exceeding 1mm after 1 year of placement). Some prosthetic complications occurred, such as screw loosening (N=1) and dissolution of cementation material (N=2). The present study describes successful outcome following the use of standard-diameter-implants placed in the posterior region, and further comprehensive maintenance practices and follow-up schedules are required.

• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.291-300
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• 2013

Purpose: Calcium phosphate (CaP)-coated implants promote osseointegration and survival rate. The aim of this study was to (1) analyze the dissolution behavior of the residual CaP particles of removed implants and (2) evaluate bone apposition of CaP-coated machined surface implants at the early healing phase. Methods: Mandibular premolars were extracted from five dogs. After eight weeks, the implants were placed according to drilling protocols: a nonmobile implant (NI) group and rotational implant (RI) group. For CaP dissolution behavior analysis, 8 implants were removed after 0, 1, 2, and 4 weeks. The surface morphology and deposition of the coatings were observed. For bone apposition analysis, block sections were obtained after 1-, 2-, and 4-week healing periods and the specimens were analyzed. Results: Calcium and phosphorus were detected in the implants that were removed immediately after insertion, and the other implants were composed mainly of titanium. There were no notable differences between the NI and RI groups in terms of the healing process. The bone-to-implant contact and bone density in the RI group showed a remarkable increase after 2 weeks of healing. Conclusions: It can be speculated that the CaP coating dissolves early in the healing phase and chemically induces early bone formation regardless of the primary stability.