• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.1
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• pp.30-35
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• 2011

Introduction: Dental implants are used routinely with high success rates in generally healthy individuals. By contrast, their use in patients with diabetes mellitus is controversial because altered bone healing around implants has been reported. This study examined the bone healing response around titanium implants placed immediately in rats with controlled and uncontrolled diabetes. Materials and Methods: Twenty rats were divided into the control, insulin-treated and diabetic groups. The rats received streptozotocin (60 mg/kg) to induce diabetes; animals in the insulin-treated group also received three units of subcutaneous slow-release insulin. A titanium implant ($1.2{\times}3\;mm$) was placed in the extraction socket of the maxillary first molar and bone block was harvested at 1, 2 and 4 weeks. Results: Bone formation around the implants was consistently (from 1 to 4 week post-implantation) slower for the diabetic group than the control and insulin-treated group. Bone morphogenesis in the diabetic rats was characterized by fragmented bone tissues and extensive soft tissue intervention. Conclusion: The immediate placement of titanium implants in the maxilla of diabetic rats led to an unwanted bone healing response. These results suggest that immediate implant insertion in patients with poorly controlled diabetes might be contraindicated.

• The Journal of Advanced Prosthodontics
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• v.6 no.1
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• pp.14-21
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• 2014

PURPOSE. The purpose of this study was to evaluate bone response to anodized titanium implants coated with the extract of black cohosh, Asarum Sieboldii, and pharbitis semen. MATERIALS AND METHODS. Forty anodized titanium implants were prepared as follows: group 1 was for control; group 2 were implants soaked in a solution containing triterpenoids extracted from black cohosh for 24 hours; group 3 were implants soaked in a solution containing extracts of black cohosh and Asarum Sieboldii for 24 hours; group 4 were implants soaked in a solution containing extracts of pharbitis semen for 24 hours. The implants from these groups were randomly and surgically implanted into the tibiae of ten rabbits. After 1, 2, and 4 weeks of healing, the nondecalcified ground sections were subjected to histological observation, and the percentage of bone-to-implant contact (BIC%) was calculated. RESULTS. All groups exhibited good bone healing with the bone tissue in direct contact with the surface of the implant. Group 2 ($52.44{\pm}10.98$, $25.54{\pm}5.56$) showed a significantly greater BIC% compared to that of group 3 ($45.34{\pm}5.00$, $22.24{\pm}2.20$) with respect to the four consecutive threads and total length, respectively. The BIC% of group 1 ($25.22{\pm}6.00$) was significantly greater than that of group 3 ($22.24{\pm}2.20$) only for total length. CONCLUSION. This study did not show any remarkable effects of the extract of black coshosh and the other natural products on osseointegration of anodized titanium implants as coating agents. Further studies about the application method of the natural products on to the surface of implants are required.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.4
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• pp.366-375
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• 2001

The objective of this study was to investigate the surface contact and screw joint stability between screw and implant interface by use of sealer. The implants evaluated in this study were Steri-Oss futures(Hexlock $3.8D{\times}10mm$: Steri-Oss, Yorba Linda, CA), and Steri-Oss staight abutment. Titanium alloy screws were used to secure abutments to implants. The other titanium alloy screws applicating sealer(Impla-Seal, Implant Support Systems, Inc. Irvine, CA) were used to secure abutments to implants. In one another sample, 6kg of force was applied during simulated intraoral movements after abutment screws were secured to the implants with sealer. All samples were cross sectioned with sandpaper and polished with $0.1{\mu}m\;Al_2O_3$. Then samples were recorded with an scanning electron microscope. The results were as follows : 1. In the case of titanium alloy screw, irregular contacts and relatively large gap were present at thread mating surface. Also abutment screw/implant interface demonstrate incomplete seating and only one surface contact of threads between implant and screw. 2. In the case of titanium alloy screw applecating sealer, sealer was present between implant and screw. Therefore implant and screw had relatively close and tight contact without the presence of large gap. 3. On the other hand, in the case of titanium alloy screw applicating sealer and dynamic loading of suprastructures, sealer was partially present between implant and screw. Conclusively, sealer fills voids, creating a barrier to moisture and bacteria. In addition, loading of suprastructures may change the situation and limit the indications for gap sealing.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.563-569
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• 2014

Materials with differing surfaces have been developed for clinical implant therapy in dentistry and orthopedics. This study was designed to evaluate bone response to titanium alloy containing Ti-32Nb-5Zr with nanostructure, anodic oxidation, heat treatment, and ibandronate coating. Rats were randomly assigned to two groups for implantation of titanium alloy (untreated) as the control group and titanium alloy group coated with ibandronate as the experimental group. Then, the implants were inserted in both tibiae of the rats for four weeks. After implantation, bone implant interface, trabecular microstructure, mechanical fixation was evaluated by histology, micro-computed tomography (${\mu}CT$) and the push-out test, respectively. We found that the anodized, heat-treated and ibandronate-coated titanium alloy triggered pronounced bone implant integration and early bone formation. Ibandronate-coated implants showed elevated values for removal torque and a higher level of BV/TV, trabecular thickness and separation upon analysis with ${\mu}CT$ and mechanical testing. Similarly, higher bone contact and a larger percentage bone area were observed via histology compared to untreated alloy. Furthermore, well coating of ibandronate with alloy was observed by vitro releasing experiment. Our study provided evidences that the coating of bisphosphonate onto the anodized and heat-treated nanostructure of titanium alloy had a positive effect on implant fixation.

• Transactions of Materials Processing
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• v.26 no.2
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• pp.108-114
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• 2017

Titanium based implants are known to improve their osseointegration by controlling surface roughness from nanometers to micrometers. Implants continuously and/or repeatedly receive irregular loads in the human body, and require a deeper understanding of the tensile and fatigue properties that can determine the fracture characteristics of the materials. In this study, the plastic deformation behavior which depends on the surface geometry of the materials during tensile tests was analyzed using the finite element method. As a result, the tensile properties were greatly decreased with increasing the sharpness of the surface. On the other hand, the average roughness had no significant effect on tensile properties. This investigation shed a light on developing titanium implants with improved osseointegration by surface treatments.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.261-281
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• 2022

Purpose: Short implants are a potential alternative to long implants for use with bone augmentation in atrophic jaws. This meta-analysis investigated the survival rate and marginal bone level (MBL) of surface-modified short vs. long implants. Methods: Electronic and manual searches were performed for articles published between January 2010 and June 2021. Twenty-two randomized controlled trials (RCTs) comparing surface-modified short and long implants that reported the survival rate with at least 1 year of follow-up were selected. Two reviewers independently extracted the data, and the risk of bias and quality of evidence were evaluated. A quantitative meta-analysis was performed regarding survival rate and MBL. Results: The failure rates of surface-modified short and long implants differed significantly (risk ratio, 2.28; 95% confidence interval [CI], 1.46, 3.57; P<0.000). Long implants exhibited a higher survival rate than short implants (mean follow-up, 1-10 years). A significant difference was observed in mean MBL (mean difference=-0.43, 95% CI, -0.63, -0.23; P<0.000), favoring the short implants. Regarding the impact of surface treatment in short and long implants, for hydrophilic sandblasted acid-etched (P=0.020) and titanium oxide fluoride-modified (P=0.050) surfaces, the survival rate differed significantly between short and long implants. The MBL differences for novel nanostructured calcium-incorporated, hydrophilic sandblasted acid-etched, and dual acid-etched with nanometer-scale calcium phosphate crystal surfaces (P=0.050, P=0.020, and P<0.000, respectively) differed significantly for short vs. long implants. Conclusions: Short surface-modified implants are a potential alternative to longer implants in atrophic ridges. Long fluoride-modified and hydrophilic sandblasted acid-etched implants have higher survival rates than short implants. Short implants with novel nanostructured calcium-incorporated titanium surfaces, hydrophilic sandblasted acid-etched surfaces, and dual acid-etched surfaces with nanometer-scale calcium phosphate crystals showed less marginal bone loss than longer implants. Due to high heterogeneity, the MBL results should be interpreted cautiously, and better-designed RCTs should be assessed in the future.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.492-516
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• 1995

This study evaluated the responses of mandibular bones of mongrel dogs to loaded hydro xylapatite(HA) and titanium plasma spray(TPS) coated endosseous dental implants, using unloaded ones as the control group. after HA and TPS coated implants were implanted, their bone reactions with vital bones have been observed with light and scanning electron microscope(SEM) at the three periods of the 4th, 12th and 20th week. These reactions have been also compared in a histomorphometric method. The elemental distribution state of implants and the interface neighboring bone tissues have been measured with the energy dispersive analysis of X-rays(EDAX). The following results were obtained ; 1. The light microscopic analysis showed osseointegration in both the control group and the occlusal force loaded group ; Its degree was shown to be higher in the long-maintained and occlusal force groups. 2. The SEM analysis showed that both groups had osseointegration, In the case of TPS-coated implants, the coated layer was divided on the bone interface. In the case of HA-coated implants, there appeared a division between the metal and coated interface. 3. In the histomorphometric analysis, the measured ratio contaction bone of TPS-coated implants was $70{\pm}19$% in the case of no occlusal force ; it was $84{\pm}13$% in the case of occlusal force. The measured ratio contacting bone of HA-coated implants was $75{\pm}18$% in the case of no occlusal force ; it was $94{\pm}9$% in the case of occlusal force. However, there was no significant difference statistically(p>0.05). 4. Both groups showed that the ratio of calcium and phosphorous increased more in the bone tissues than on the bone to implant interface.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.575-580
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• 2005

Transitional implants were developed to support provisional restorations and to allow for load-free osseointegration of conventional implants while a patient was provided with immediate esthetics and function and are usually placed simultaneously at the time of definitive implant placement. Transitional implants are placed in a non-submerged fashion in a single-stage surgery and are designed to be immediately loaded. They generally are made of commercially pure titanium or titanium alloy and are designed as 1-piece implants composed of root and crown replacement segments. Transitional implants can be used in a wide range of indications, such as basic use as temporary implant, to support and protect the primary implants during the healing phase, single crown in the edentulous anterior region of mandibular, anchorage for orthodontic treatment, support a surgical and radiographic template, and primary implant to extremely atrophied alveolar crests of the mandible and maxilla. This article describes the clinical use of transitional implants to support the provisional complete denture and single crown in the restricted edenturous central incisor region of mandible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.306-318
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• 2008

Anodic spark deposition method(ASD) surface treated titanium implant possesses a considerable osteoconductive potential that promoting a high level of implant osseointegration in normal bone. The purpose of this study was to observe the ASD implant's osseointegration in the osteoporosis-induced animal model. Twenty four rats, 10 weeks of age, were ovarectomized and 5 weeks later divided into two groups : ASD implant group and control implant group. Titanium screw implants (diameter; 2.0 mm, length, 3.5 mm; pitch-height, 0.4 mm) were designed for this study. Experimental implants were ASD treated and no treatment on control implants. ASD implants and control implants were placed in to left tibiae of rats. The rats were sacrificed at different time interval(1, 2, 4 and 8 weeks after implantation) for histopathologic observation and immunohisto-chemistrical observation, with collagen type Ⅰ, fibronectin, integrin ${\alpha}_2{\beta}_1$ and integrin ${\alpha}_5{\beta}_1$ antibodies. The results obtained from this study were as follow: 1. Histopathologic findings, overall tissue response and the pattern of bone formation in both groups were similar. In ASD group, more newly formed bone was seen at 1 week and 2weeks than control group. 2. The levels of type Ⅰ collagen and fibronectin expression were the most abundant at 2weeks and decreased gradually in both groups. Fibronectin and type Ⅰ collagen expression in ASD group were stronger than control group but no significance. 3. The levels of integrin ${\alpha}_2{\beta}_1$ and Integrin ${\alpha}_5{\beta}_1$ expression were most abundant at 2 weeks and decreased gradually in both groups. No significant difference was observed in both groups. From this results, anodic oxidized titanium implants were more advantages in early stage of bone formation than control group, but have no significance in tissue responses and late bone formations. It could be stated that although anodic oxidized titanium implant possesses considerable osteoconductive potential but in osteoporotic bone condition dental implant procedure should performed after improving or treating the osteoporotic bone condition.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.1
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• pp.148-169
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• 1994

The concept of biologic attachment of load-bearing implants has developed over the past decades as an alternative to the difficulties associated with long term implantation using mechanical fixation and bone cement. The choice of implant material is also as critical an element as site preparation or insertion procedure. The properties of implants that affect host tissue responses are not limited to chemical composition alone, but also include shape, surface characteristics, site of implantation, and mechanical interaction with host tissues. Initial mechanical interlocking prevents micromotion and may be a prerequisite for direct bone apposition. A hard tightening of screws does not necessarily mean a stronger fixation and final tightening of the fixtures is dependent on the experience of the operator. Removal torque is lower than insertion torque. The purpose of this study was to investigate differences in the removal torques at the bone-implant interface of polished and sandblasted Titanium. This experiment will give insight into important factors that must be considered when interpreting in vivo screwing forces on implants during the connection of the transmucosal abutments. We evaluated the significance of different surface textures by comparison of the withdrawal forces necessary for removal of otherwise identical rough and polished implants of Titanium and also evaluated interfacial response on the light microscopic level to implant surface. And the priority of the area of insertion on osseointegration were evaluated. 9 Titanium implants - among them, 3 were for the developmental - of either a smooth or rough surface finish were inserted in the dog mandible in the right side. 3 months later Kanon Torque Gauge was used to unscrew the implants. The results were as follows : 1. No significant difference was seen in the removal torque due to variation in surface treatment, 23 Ncm for the sandblasted and 23.33 Ncm for the polished surface (p>0.05). 2. Implants in the anterior (25 Ncm) mandible showed better resistance to unscrewing in comparison to ones in the posterior (18 Ncm) region (p<0.05). 3. Developmental fixtures (22 Ncm) had similar pullout strength to the control group (p>0.05).