• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.7-14
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• 2006

• Journal of Korean Dental Science
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• v.5 no.2
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• pp.48-53
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• 2012

Various ceramic implant systems made of yttria-stabilized tetragonal zirconia polycystal (Y-TZP) have become commercially available in recent years. A search of the literature was performed to assess the clinical success of dental Y-TZP implants and whether the osseointegration of Y-TZP is comparable to that of titanium, the standard implant material. No controlled clinical studies in humans regarding clinical outcomes or osseointegration could be identified. Clinical data were restricted to case studies and case series. Only 7 animal studies were found. Osseointegration was evaluated at 4 weeks to 24 months after placement in different animal models, sites and under different loading conditions. The mean bone-implant contact percentage was above 60% in almost all experimental groups. In studies that used titanium implants as a control, Y-TZP implants were comparable to or even better than titanium implants. Surface modifications may further improve initial bone healing and resistance to removal torque. Y-TZP implants may have the potential to become an alternative to titanium implants but cannot currently be recommended for routine clinical use, as no long-term clinical data are available.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.224-235
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• 1996

Early implantation before sufficient ossification has taken place usually results in osseointegartion failure due to reduced bone-fixture interface area. However, various studies have shown successful osseointegration results following immediate implants concurrently with GTR. The clinical trends have been to shorten the patients' edentulous state by immediate implantation, and reduce the alveolar bone resorption. However, it may be difficult to attain the complete soft tissue coverage of the sites, increasing the chance of infection. Furthermore, there may be more studies needed on the clinical behaviors of e-PTFE membranes, various modofications in the membrane materials and bone graft materials. Various animal and clinical studies have been reported on the successful osseointagration following immediate implantation, but the long-term follow-up studies are limited. The present study investigated 16 immediately-implanted implants with GTR therapy with or without calcium carbonate grafting on 11 patients 3 years after installation and 24-30 months after functional loading. Based on the clinical, radiographic and histologic findings, the following results have been attained. 1. Clinically, stability has been shown on all 16 implants throughout the investigated periods. 2. Radiologically, the alveolar bone loss has progressed up to the polished neck portion but not beyond it, suggesting the progressive osseointegration from the GTR therapy. 3. The GTR method used in the present study is easy to use clinically, and may be appied in the regeneration of ossoeous defects around implants and in the immediate implantation. 4. The difficulty in complete tissue coverage may be avoided by delaying the installation for 2 to 3 weeks after the extraction allowing certain degree of soft tissue healing.

• Journal of Periodontal and Implant Science
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• v.43 no.1
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• pp.18-23
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• 2013

Purpose: The purpose of this study was to evaluate the osseointegration of calcium phosphate (CaP)-coated implants by ion beam assisted deposition with a lack of primary stability. Methods: A total of 20 CaP-coated implants were bilaterally placed in the mandible of five dogs. In the rotational implant group, the implants were inserted in oversized drilled sockets without mechanical engagement, while the conventional surgical protocol was followed in the control group. Each group was allowed to heal for 4 and 8 weeks. The bone-to-implant contact (BIC, %) was measured by a histometric analysis. Results: All of the implants were well-maintained and healing was uneventful. In the histologic observation, all of the implants tested were successfully osseointegrated with a high level of BIC at both observation intervals. There was no significant difference in BIC among any of the groups. Conclusions: Within the limitation of this study, successful osseointegration of CaP-coated implants could be achieved in unfavorable conditions without primary stability.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.3
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• pp.238-244
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• 2000

The present study was aimed to investigate the effect of osseointegration according to implant placement timing in the distracted alveolar bone using intraoral distraction device. Six adult mongrel dogs of either sex, weighing about 15kg, were used. The animals were divided into 4-week and 8-week groups according to the timing of implant installation. The left upper and lower premolars and first molars were extracted and an alveoloplasty was performed to simulate an atrophic ridge. After 12 weeks of healing, a segmental osteotomy was made and an intraoral distraction device which was designed for augmentation of vertical height of the edentulous ridge was applied. Latency period was allowed for 5 days and then distraction was made at a rate of 1.2mm/day for 8 days. Four or eight weeks after distraction, implants were installed. Twelve weeks after implant installation, the animals were sacrificed. Macroscopic, radiographic, and histologic examinations of distracted alveolar ridge were performed. No significant abnormalities such as infection and dehiscence of overlying soft tissue were observed. Radiographically, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in the both groups. The satisfactory osseointegration was achieved in the distracted gap of the both groups, but fibrous tissue appeared on the buccal side of implant in the distracted gap in 4-week group. These results suggest that proper timing of implant installation is 8 weeks rather than 4 weeks after distraction when dental implant is to be placed onto the distracted bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.6
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• pp.345-351
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• 2016

Objectives: This study compared the impact of implant surface treatment on the stability and osseointegration of implants in dog mandibles. Materials and Methods: Six adult dogs received a total of 48 implants that were prepared using four different surface treatments; resorbable blast media (RBM), hydroxyapatite (HA), hydrothermal-treated HA, and sand blasting and acid etching (SLA). Implants were installed, and dogs were separated into 2- and 4-week groups. Implant stability was evaluated via Periotest M, Osstell Mentor, and removal torque analyzers. A histomorphometric analysis was also performed. Results: The stability evaluation showed that all groups generally had satisfactory values. The histomorphometric evaluation via a light microscope revealed that the HA surface implant group had the highest ratio of new bone formation on the entire fixture. The hydrothermal-treated HA surface implant group showed a high ratio of bone-to-implant contact in the upper half of the implant area. Conclusion: The hydrothermal-treated HA implant improved the bone-to-implant contact ratio on the upper fixture, which increased the implant stability.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.167-189
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• 1992

Frictional heat produced by cutting tools during dental implantation procedure may destroy the surrounding bone tissue and regenerative capacity and interfere ossointegration by formation of undifferentiated connective tissue. To study the effect of frictional heat according to various rotational speeds on the regenerative capacity of surrounding bone tissue, 13 ITI HS implants (8 mm) were inserted at 4 mongrel dogs. Temperatures were measured using thermocouple located 6 mm below from the marginal crest and 0.5 mm from the periphery of trephine mill during implant bed preparation. After 4 and 9 months, animals were sacrificed and specimens were examined using x-rays and light microscope. Results were as follows: 1. With drill speeds of 300, 800, 2,000, 3,500 rpm and saline irrigation, temperatures of surrounding bone were decreased from $-2.9^{\circ}\;to\;-1.7^{\circ}C$. Temperature rises of $2.0^{\circ}\;and\;2.1^{\circ}C$ were recorded with a drill speed of 5,000 rpm and irrigation. 2. With drill speeds of 800, 3,500, 5,000 rpm and no irrigation, temperatures of surrounding bone rose from $+1.5^{\circ}\;to\;+6.8^{\circ}C$, but maximum temperature was $40^{\circ}C$ at 5,000 rpm. 3. On radiographic examination, bone resorptions were observed at the upper half of implant of 5,000 rpm without irrigation and one case of 5,000 rpm with irrigation. 4. Osseointegration was unsuccessful in cases of 3,500, 5,000 rpm without irrigation due to fibrous connective tissue formation to the outer surface and hollow, but it was successful in a case of 800 rpm without irrigation. 5. Osseointegration was successful in cases of 300, 800, 2,000 and 3,500 rpm with irrigation. But fibrous connective tissue formation was observed at the hollow of implant inserted with 5,000 rpm with irrigation.

• Journal of Periodontal and Implant Science
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• v.34 no.4
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• pp.699-709
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• 2004

The present study was performed to evaluate histomorphological difference in various surface-treated implants in beagle. Implants($Implantium^{(R)}$, Dentium Co. Korea) with pure titanium machined surface, acid treated surface, and $Al_2O_3(50{\sim}100\;{\mu}m)$blasted with acid treated surface were used in this study. All mandibular premolars of $1.5{\sim}2$ year old male beagle dogs were extracted. At 3 months after extraction, the implants(${\Phi}$ 4mm, l 6mm) were installed. The beagle were sacrificed at 1, 3 months after installation and then tissues including implants were prepared for non-decalcified specimens. These specimens were analyzed comparatively under light microscope. The results of this study were as follow 1. Higher rate of osseointegration were showed in the $Al_2O_3(50{\sim}100\;{\mu}m)$blasted with acid-treated surface. 2. Increased osseointegration were showed in the $Al_2O_3(50{\sim}100\;{\mu}m)$blasted with acidtreated surface with time. 3. Higher maturation of integration were showed in the $Al_2O_3(50{\sim}100\;{\mu}m)$blasted with acid-treated surface. In conclusion, surface treatment of $Al_2O_3blasted$ with acid might be considered to shorten healing time and improve success rate as increasing contact of implant and bone.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.293-298
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• 2005

Osseointegrated prosthetic auricular reconstruction can be classified as either direct or indirect. In the $Br{\aa}nemark $ system of direct osseointegration, implants are placed into the mastoid process of the temporal bone. In the Epitec system of indirect osseointegration, implants are inserted into a three-dimensional carrier plate that is fixed to the mastoid by means of screws. We experienced forty-four cases using the indirect system and seventeen cases using the direct system. We compared with two systems by complications, such as skin reaction, implant loosening, implant loss. There were no specific differences in the skin reaction around the implants and abutments in relation to age or system used. The degree of skin reaction was different according to the conditions around the implant: in cases of virgin microtia, a skin flap was used to cover the implant, in contrast to grafted skin coverage for failed autogenous reconstruction. In both systems, the skin reaction was more severe and frequent in skin flap than in grafted skin. Loosening of the implant was more frequent in the direct system; however, accidental detachment of the implant from the abutment was more frequent in the indirect system. To reduce complications of skin reaction in osseointegrated prosthetic auricular reconstruction, it is important for soft tissue around implant to immobilize. Therefore, grafted skin is better than skin flap as soft tissue around implant. And immobilization of soft tissue around implant by wound dressing is major facter.

• Applied Microscopy
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• v.34 no.4
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• pp.277-283
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• 2004

This paper reports that the ultrastructural nature of the interface process between the implants and surrounding bone has been studied after in vivo 1, 4, 8, 12 weeks of implantation of smooth machined implants into rabbit tibias. There was no indication of the fibrous connective tissue formation around the implant that imply intolerance of the bone tissue towards the implant after 1 week of implantation. The regions showing direct bone tissue bonding to the smooth machined implant contained osteoblast activating across the interface in the direction after 4 weeks of implantation. The reaction of a smooth machined implant caused in the first instance formation of an amorphous woven bone, which transformed into a mineralized bone containing collagen fibers. After 8 weeks of implantation, the activities of osteoblast initiated osseointegration forming bone matrix at the interface. During this period, the osteoblast surrounded with a matrix consisting of collagen bundles running in various directions. In the interface area between newly formed bone tissue and implants which has been inserted in rabbit tibias for 12 weeks, the implant and mineralized bone was separated by an amorphous electron dense material layer about $1{\sim}1.5{\mu}m$ in thickness.