• 대한치과의사협회지
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• 제47권12호
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• pp.823-829
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• 2009

Purpose : The aim of this study was to evaluate the survival rate of sintered porous-surfaced implants placed in the edentulous posterior mandibles, in relation to implant length and diameter, crown-to-implant ratio, and types of prostheses, for a maximum of eight years of functioning. Material and Methods : The study group consisted of 43 partially edentulous patients who visited Catholic University Hospital of Daegu and one private dental clinic. A total of 122 sintered porous-surfaced implants n $Endopore^{(R)}$ (Inn ova Life Sciences, Toronto, Ontario, Canada) -- were placed in the edentulous posterior mandibles, Two diameter sizes (4.1 mm and 5.0 mm) and four lengths (5.0 mm, 7.0 mm, 9.0 mm, and 12.0 mm) were used. One hundred and three implants were splinted and 21 implants were nonsplinted. The survival rates of the implants in relation to length, diameter, crown-to-implant ratio, and types of prostheses were investigated. Statistical data were analyzed using SPSS Win.Ver 14.0 software with the Chi-square test. Results : The survival rate of the 4.1mm diameter implants was 100% and 91.2% for the 5.0mm diameter implants. The survival rates of the implants of differing diameters were found to be statistically different (p=0.005). The survival rates of both the 5.0mm and 7.0 mm length implants were 100%. The survival rate of the 9.0mm length implants was 97.9% and for the 12.0mm length implants was 95.1%. There was no statistical difference in survival rates for the differing lengths of implants. Of the 103 prostheses that were splinted, the survival rate was 98.0%. The survival rate of splinted prostheses was higher than that of the non-splinted prostheses, but was found to be not statistically different. There were no failed cases when the crown-to-implant ratio was under 1.0. When the crown-to-implant ratio was between 1.0 and 1.5, the failure rate of the implants was 6.7%. No failure was recorded with the ratio range of 1.5 to 2.0. Relative to the crown-to-implant ratio of 1.0, the failure rates were statistically different (p=0.048). Discussion and Conclusion : The cumulative survival rate of the porous-surfaced implants placed in the edentulous posterior mandibles was 97.5%. Short porous-surfaced implants showed satisfactory results after a maximum of nine years of functioning in the edentulous posterior mandibles.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권5호
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• pp.361-366
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• 2009

Purpose: The purpose of this retrospective report was to analyze long-term survival rate of sintered porous-surfaced dental implant ($Endopore^{(R)}$ Dental Implant system, Innova Corporation, Toronto, ON, Canada). Methods: 61 partially edentulous patients were received a total of 127 Endopore dental implants in the maxilla. Of the 127 implants, 24 implants were restored with individual (ie, non-splinted) crowns, while 103 implants were splinted to other implants. Medical records and radiographs were evaluated and analyzed by the cumulative survival rate, location of implants, implants length and diameter, crown/implant ratio and whether the implant was splinted. Chi squire test was used statistically. Result: Of the 127 implants, 8 implants (6.3%) were removed and and cumulative survival rate was 93.7%. Conclusion: Endopore implants showed satisfactory results after up to 8 years function periods in the edentulous posterior maxilla.

• 한국재료학회지
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• 제16권3호
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• pp.173-177
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• 2006

Porous surfaced Ti implant compacts were fabricated by electro-discharging-sintering (EDS) of atomized spherical Ti powders. Powders of $50-100{\mu}m$ in diameter were vibratarily settled into a quarts tube and subject to a high voltage and high density current pulse in Ar atmosphere. Single pulse of 0.7 to 2.0 kJ/0.7 gpowder, from 150, 300, and $450{\mu}F$ capacitors was applied in less than $400{\mu}sec$ to produce twelve different porous-surfaced Ti implant compacts. The solid core formed in the center of the compact shows similar microstructure of cp Ti which was annealed and quenched in water. Hardness value at the solid core was much higher than that at the particle interface and particles in the porous layer, which can be attributed to both heat treatment and work hardening effects induced by EDS. Compression tests were made to evaluate the mechanical properties of the EDS compacts. The compressive yield strength was in a range of 12 to 304MPa which significantly depends on input energy. Selected porous-surfaced Ti-6Al-4V dental implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered Ti dental implants fabricated by conventional sintering process.

• 한국분말재료학회지
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• 제12권5호
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• pp.332-335
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• 2005

Porous and porous surfaced Ti-6Al-4V implant compacts were fabricated by electro-discharge-sintering (EDS) of atomized spherical Ti-6Al-4V powders with a diameter of $100-150\;{\mu}m$, The solid core formed in the center of the compact after discharge was composed of acicular ${\alpha}+{\beta}$ Widmanstatten grains, The hardness value at the solid core was much higher than that at the particle interface or particles in the porous layer, which can be attributed to both heat treatment and work hardening effects induced from EDS, The compressive yield strength was in a range of 19 to 436 MPa which significantly depends on both input energy and capacitance, Selected porous-surfaced Ti-6Al-4V implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered Ti dental implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권1호
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• pp.52-59
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• 2008

The geometric design of an implant surface may play an important role in affecting early osseointegration. It is well known that the porous surfaced implant had much benefits for the osseointegration and the early stability of implant. However, the porous surfaced implant had weakness from the transgingival contamitants, and it resulted in alveolar bone loss. The other problem identified with porous surface implant is the loss of physical properties resulting from the bead sintering process. In this study, we developed the new bead coating implant to overcome the disadvantages of porous surfaced implant. Ti-6Al-4V beads were supplied from STARMET (USA). The beads were prepared by a plasma rotating electrode process (PREP) and had a nearly spherical shape with a diameter of 75-150 ${\mu}m$. Two types of titanium implants were supplied by KJ Meditech (Korea). One is an external hexa system (External type) and the other is an internal system with threads (Internal type). The implants were pasted with beads using polyvinylalcohol solution as a binder, and then sintered at 1250 $^{\circ}C$ for 2 hours in vacuum of $10^{-5}$ torr. The resulting porous structure was 400-500 ${\mu}m$ thick and consisted of three to four bead layers bonded to each other and the implant. The pore size was in the range of 50-150 ${\mu}m$ and the porosity was 30-40 % in volume. The aim of this study was to evaluate the osseointegration of the newly developed dental implant. The experimental implants (n=16) were inserted in the unilateral femur of 4 mongrel dogs. All animals were killed at 8 weeks after implantation, and samples were harvested for hitological examination. All bead coated porous implants were successfully osseointegrated with peripheral bone. The average bone-implant contact ratios were 84.6 % (External type) and 81.5 % (Internal type). In the modified Goldner's trichrome staining, new generated mature bones were observed at the implant interface at 8 weeks after implantation. Although, further studies are required, we could conclude that the newly developed vacuum sintered Ti-6Al-4V bead coating implant was strong enough to resist the implant insertion force, and it was easily osseointegrated with peripheral bone.

• 대한치과보철학회지
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• 제44권5호
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• pp.617-627
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• 2006

Statement of problem: HA has been used as a coating material on Ti implants to improve osteoconductivity. However. it is difficult to form uniform HA coatings on implants with complex surface geometries using a plasma spraying technique. Purpose : To determine if Ti6Al4V sintered porous-surfaced implants coated with HA sol-gel coated and hydrothermal treated would accelerate osseointegration. Materials and Methods : Porous implants which were made by electric discharge were used in this study. Implants were anodized and hydrothermal treatment or HA sol-gel coating was performed. Hydrothermal treatment was conducted by high pressure steam at $300^{\circ}C$ for 2 hours using a autoclave. To make a HA sol, triethyl phosphite and calcium nitrate were diluted and dissolved in anhydrous ethanol and mixed. Then anodized implant were spin-coated with the prepared HA sols and heat treated. Samples were soaked in the Hanks solution with pH 7.4 at $37^{\circ}C$ for 6 weeks. The microstructure of the specimens was observed with a scanning electron microscope (SEM), and the composition of the surface layer was analyzed with an energy dispersive spectroscope (EDS). Results : The scanning electron micrographs of HA sol-gel coated and hydrothermal treated surface did not show any significant change in the size or shape of the pores. After immersion in Hanks' solution the precipitated HA crystals covered macro- and micro-pores The precipitated Ca and P increased in Hanks' solution that surface treatment caused increased activity. Conclusion : This study shows that sol-gel coated HA and hydrothermal treatment significantly enhance the rate of HA formation due to the altered surface chemistry.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권4호
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• pp.278-286
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• 2011

Introduction: This study examined the predictability of new bone formation in the pneumatized maxillary sinus using only fibrin-rich blocks with concentrated growth factors as an alternative to bone grafts. Materials and Methods: Maxillary sinus augmentation was performed in thirty-three patients with a deficient alveolar bone height (mean 3.9 mm). All patients were treated consecutively with sinus membrane elevation via the lateral window approach and panoramic radiograms and cone-beam computed tomograms were taken to evaluate the remaining bone height and the new bone formation in the maxillary sinus, before and after surgery. Four biopsy specimens were taken at the time of implant consolidation (after an average of five months healing) and were stained by H & E and Trichrome staining. Results: None of the patients had postoperative complications during implant consolidation. After an average of 5 months since sinus augmentation, newly formed bone was observed in all cases by a radiographic evaluation. In 4 biopsy samples, newly formed bone was observed along the floor of the replaced bony window. The osteoblast lining and well distinguished Osteocytes in the lacunas were observed in the newly formed bone. Of the 74 implants (4 different surfaced implants - resorbable blast media-surfaced (RBM), Hydroxyapatite (HA) coated, acid-etched, sintered porous-surfaced implant) placed, one RBM implant failed. The success rate was 98.6% after a mean of 15 months. Discussion: These results suggest that maxillary sinus augmentation using fibrin rich block with concentrated growth factors is a successful and predictable technique.