• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.1
• /
• pp.31-41
• /
• 2008

Statement of problem: It has been proved that Pleurotus eryngii Quel and Eleutherococcus senticosus have antiinflammatory action and not only stimulates the proliferation and activity of osteoblast but inhibits the generation and activity of osteoclast in vitro. Pleurotus eryngii Quel and Eleutherococcus senticosus are the main component of $OPB-K^{(R)}$. Purpose: The purpose of this study was to evaluate $OPB-K^{(R)}$ which enhances the healing rate of peri-implant bone and the bone mineral density. Materials and methods: Thirty six specially designed implants were installed in the tibia of rats. The group medicated with $OPB-K^{(R)}$ was the experimental group, and that without was the control group. hen the implant stability was measured by $Periotest^{(R)}$. Bone mineral density and histological measurement were conducted at the 2nd, 4th and 6th week $Periotest^{(R)}$ and bone mineral density values were analyzed statistically with independent t-test at 95% confidence level(p<0.05). Results: The results of this study were as follows : 1. There was no statistically significant difference in $Periotest^{(R)}$. values between the experimental group and control group at the 2nd week, however, on the 4th and 6th week there was significant difference(p<0.05). 2. There was no statistically significant difference in bone mineral density between the experimental group and control group at the 2nd and 4th week, however on the 6th week there was significant difference(p<0.05). 3. Histological analysis showed difference in osseointegration on the 4th and 6th week between the groups. Conclusion: From the results, it is concluded that the $OPB-K^{(R)}$ medicated group showed statistically better results in bone density and stability than the control group. Clinically it would be better to medicate $OPB-K^{(R)}$ to patients for a long period of time after implantation to get superior results.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.1
• /
• pp.9-17
• /
• 2014

Purpose: The purpose of this study was to compare zirconia implants with titanium implants from the view point of biomechanical stability and histologic response on osseointegration when those were placed with xenograft materials. Materials and methods: Specimens were divided into two groups; the control group was experimented with eighteen titanium implants which had anodized surface and the experimental group was experimented with eighteen sandblasted zirconia (Y-TZP) implants. At the tibias of six pigs, implants were installed into bone defect sites prepared surgically and treated with resorbable membranes and bovine bone. Two pigs were sacrificed after 1, 4 and 12 weeks respectively. Each implant site was sampled and processed for histologic and histomorphometric analysis. The stability of implants was evaluated with a $Periotest^{(R)}$. And the interfaces between bone and the implant were observed with a scanning electron microscope. Results: In stability analysis there was no significant difference between Periotest values of the control group and the experimental group. In histologic analysis with a light microscope after 4 weeks, there was new bone formation with the resorption of bovine bone and the active synthesis of osteoblasts in both groups. In bone-implant contact percentage there was significant difference between both groups (P<.05). In bone area percentage there was no significant difference between both groups. In analysis of both groups with a scanning electron microscope there was a gap between bone and a surface at 4 weeks and it was filled up with bone formed newly at 12 weeks. Conclusion: When accompanied by xenograft using membrane, bone to implant contact percentage of zirconia implants used in this experiment was significantly less than that of the titanium implants by surface treatment of anodic oxidation. So, it is considered that the improvement of zirconia implant is needed through ongoing research on surface treatment methods for its practical use.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.23 no.1
• /
• pp.34-40
• /
• 2014

There are several treatment options for rehabilitation of partial edentulism including the use of conventional or implant-retained fixed prostheses. However, such prosthetic options cannot always be possible because of compromised general and oral health (i.e. loss of supporting tissues, medical reasons, extensive surgical protocol and osseointegration failure of dental implant) as well as the affordability of patients. In some cases, removable partial denture provides easier access for oral hygiene procedures and the ability to correct discrepancies in dental arch relationships than implant fixed prosthesis. Recently, Implant Supported Removable Partial Denture (ISRPD) where to place dental implant in strategic position has been suggested to improve the limitation and shortcomings of conventional RPD. ISPRD can overcome mechanical limition of conventional RPD by placing implant in a favorable position and can be cost-effective, prosthetic solution for partially edentulous patients who are not immediate candidates for extensive, fixed implant supported restorations. Incorporation of dental implants to improve the RPD support and retention and to enhance patient acceptance should be considered when treatment planning for RPD. In this case, 59 years old male patient who received dental treatment of implant fixed prosthesis on both side of the upper jaw and implant overdenture on lower jaw showed implant abutment screw fracture on #15i and osseointegration failure on multiple number of implants. After removing failed implants, we planned ISRPD using #15i,24i,25i,26i and #23 natural tooth for RPD abutment. We fabricated #23 surveyed crown,#24i=25i=26i surveyed bridge and #15i gold coping for support,retention and stability for RPD. Periodic follow up check for 2years has been performed since the ISRPD delivery to the patient. No sign of screw loosening, fracture or bone resorption around abutment implants were detected.

• Journal of Life Science
• /
• v.32 no.11
• /
• pp.855-864
• /
• 2022

The pharmacological efficacy of Dipterocarpus tuberculatus Roxb. has been verified in only several fields including photoaging, inflammation, hepatotoxicity, acute gastritis and osseointegration. To identify the novel functions of Dipterocarpus tuberculatus Roxb. on anti-obesity, inhibitory effect on lipid accumulation and stimulatory effect on lipolysis were investigated in MDI (3-isobutyl-1-methyl-xanthine, dexamethasone, and insulin) stimulated 3T3-L1 adipocytes treated with methanol extracts of Dipterocarpus tuberculatus Roxb. (MED). Lipogenic targets, including lipid accumulation, level of lipogenic transcription factors, and expression of lipogenic regulators, were downregulated in MDI-stimulated 3T3-L1 adipocytes treated with MED without any significant cytotoxicity. Also, MED treatment inhibited the mRNA levels of adipogenic targets including peroxisome proliferator-activated receptor (PPAR)γ and CCAAT-enhancer binding protein (C/EBP) α, as well as lipogeic targets including adipocyte fatty acid binding protein 2 (aP2) and fatty acid synthetase (FAS) in MDI-stimulated 3T3-L1 adipocytes. A similar decrease patterns were detected in Oil red O stained lipid droplets of MED treated MDI-stimulated 3T3-L1 adipocytes. Furthermore, several lipolytic targets, such as cAMP concentration, concentration of free glycerol, expression level of lipases, including ATGL, perilipin and HSL, were upregulated in MDI-stimulated 3T3-L1 adipocytes treated with MED. These results show that MED has a novel role as a lipogenesis inhibitor and lipolysis stimulator in MDI-stimulated 3T3-L1 adipocytes.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.4
• /
• pp.279-286
• /
• 2014

Purpose: The aim of this study was to investigate the effect of implant thread profile on the marginal bone stresses which develop during implant insertion. Materials and methods: Four experimental implants were created by placing four different thread systems on the body ($4.1mm{\times}10mm$) of the ITI standard implant. The thread types studied in this study included the buttress, v-shape, reverse buttress, and square shape threads. In order to examine the insertion stress generation, 3D dynamic finite element analysis was performed which simulated the insertion process of implants into a 1.2 mm thick cortical bone plate (containing 3.5 mm pilot hole) using a PC-based DEFORM 3D (ver 6.1, SFTC, Columbus, OH, USA) program. Results: Insertion stresses higher than human cortical bone developed around the implants. The level of insertion stresses was much different depending on the thread. Stress level was lowest near the v-shape thread, and highest near the square shaped thread. Difference in the interfacial bone stress level was more noticeable near the valley than the tip of the threads. Conclusion: Among the four threads, the v-shape thread was turned out to minimize the insertion stress level and thereby create better conditions for implant osseointegration.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.1
• /
• pp.67-76
• /
• 2008

Implant requires long lasting, strong osseointegration using bio-mechanical interlocking by bone ingrowth. In regarding the size level for bone ingrowth, the micro-patterning would enhance bone response. Micro-patterning can increase the area contacting the bone tissues. Therefore, it may distribute the load to the surrounding bone tissue, more effectively. This study compared and analyzed the load distributing effect with the shape and number of micro-patterning. For the optimal comparison of threads, the assumptions different from general finite element analysis model were made. It was assumed that the implant was axisymmetric and infinitely long. The implant was assumed to be completely embedded in the infinitely long cortical bone and to have 100% bone apposition. The implant-bone interface had completely fixed boundary conditions and received an infinitely big axial load. The condition of threads were as follows. The reference model 1 had conventional thread. Model 2 had 2 micro-patterns on the upper flank of the thread. Model 3 had 2 micro-patterns on the lower flank of the thread. Model 4 had 2 micro-patterns on the upper and lower flanks of the thread. Model 5 had 3 micro patterns on the upper and lower flanks of the thread. The results were as follows: 1. The thread with micro-patterns distributed stress better than the conventional thread. 2. The thread with micro-patterns on the lower flank distributed stress better than that with micro-patterns on the upper flank. 3. The thread with 3 micro-patterns distributed stress better than that with 2 micro-patterns, However, an area with stress concentration occurred.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.1
• /
• pp.41-56
• /
• 2008

The methods of surface modification of commercial implants were various according to the manufacturer. Surface modification of implant may produce diverse physical and chemical surface characteristics resulted from the treatment method and treatment condition. As a result, the bone response might be different. Even though surface modified implants have been used clinically, most researches are focusing on the bone response of surface modified implants comparing to machined implants rather than surface modified commercial implants. This study compare and analyze bone responses of 4 surface modified commercial implants with different shapes and surfaces. Eighty surface modified commercial implants with 4 different surface characteristics were installed in the tibia of white Newzealand rabbits. Biomechanical stability tests and histomorphometric evaluation were done. The results were as follows: 1. Surface modified commercial implants showed stable osseointegration at 6 weeks after installation. 2. Histomorphometric evaluation showed that there was no significant differences in bone to implant contact among 4 different commercial titanium implants. In comparing the implants with different shape the measurement of bone growth in subcortical area would be more reliable than entire bone to implant contact length. 3. Resonance Frequency Analysis showed that there was no significant differences among 4 types of implants, even though they were significantly different in installation. 4. There was significant differences in interfacial shear strength among 4 type of implants. 5. It is difficult to observe accurate bone to implant interface using Micro-CT. However, it is possible to measure the entire contact length of the implant to the bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.3
• /
• pp.276-284
• /
• 2008

Purpose: The purpose of this study was to observe the effect of calcium and vitamin D to the titanium implant osseointegration in the osteoporosisinduced animal model. Material and method: Thirty-two rats, 10 weeks of age, were divided into two groups: experimental group was ingested additional calcium and vitamin D, and a control group was not. Titanium screw implant(diameter, 2.0 mm; length, 3.5 mm; pitch-height 0.4 mm) were placed into tibia of 32 rats, 16 in the control group and 16 in the experimental group. The rats were sacrificed at 1, 2, 4 and 8 weeks after implantation for histopathologic examination, histomorphometric analysis and immunohistochemistry with fibronectin and collagen type I antibody. Result: In histopathological findings, newly formed bone was seen at 2 weeks and became lamellar bone at 4 weeks, and mature trabecullar bone was seen at 8 weeks in experimental group. In control group, thickness of regenerated bone increased till 4 weeks gradually and trabecullar bone was seen at 8 weeks. In histomorphometric analysis, marrow bone density increased significantly in experimental group compared to control group. Fibronectin immunoreactivity was strong at 2 weeks in experimental group and reduced after 4 weeks gradually. But it was maintained continuously from 2 to 8 weeks in control group. Collagen type I immunoreactivity was very strong from 2 to 4 week in experimental group. And the amount of Collagen type I expression was more abundant in experimental group. Conclusion: The results of this study suggest that calcium and vitamin D supplementation promote bone healing around titanium implants in osteoporosis induced animals.

• Korean Journal of Veterinary Research
• /
• v.43 no.2
• /
• pp.289-294
• /
• 2003

This study aimed to determine of osseointegration following dental implantation in the dog mandible using bone scintigraphy. Five mongrel dogs, weighing approximately 8.5 kg and averaging 1.8 years of age, without active periodontal disease were used. During the entire study period, all dogs were fed a soft commercial diet and water ad libitum to minimize functional loading of the implant. Titanium alloy implant systems 10 mm in length and 4 mm in diameter were chosen for insertion. Twelve weeks prior to implantation, the second and third left mandibular premolars in each dog were extracted for the dental implant insertion. Before the dental implantation procedures and 0, 4, 8, and 12 weeks after the insertions, clinical observation, radiography and bone scintigraphy were conducted. The scintigraphy was obtained using a large field of view gamma camera equipped with a paralled-hole, low-energy collimator about 3 hours after intravenous injection of Tc-99m-MDP (8 mCi/dog) to the dogs. There were not inflammation sign after insertion of dental implants on the mandible in dogs. Implants were slightly movable at the first and fourth weeks, and there was no mobility after 8 weeks. Twelve weeks after dental implantation, the bone uptake scintigraphy of peri-implant bone was similar to that of normal alveolar bone, indicating that peri-implant bone was completely regenerated by new bone. In conclusion, we recommend stable implant fixation with alveolar bone for the accurate and safe repair of teeth loot due to decacy, trauma or peridontal disease. Titanium alloy implants were optimal due to their biocompatibility.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.3
• /
• pp.363-378
• /
• 2005

Statement of problem. Hydroxyapatite(HA) coated titanium surfaces have not yet showed the reliable osseointegration in various conditions. Purpose. This study was aimed to investigate microstructures, chemical composition, and surface roughness of the surface coated by the hydrothermal method and to evaluate the effect of hydrothermal coating on the cell attachment, as well as cell proliferation. Material and Methods. Commercially pure(c.p.) titanium discs were used as substrates. The HA coating on c.p. titanium discs by hydrothermal method was performed in 0.12M HCl solution mixed with HA(group I) and 0.1M NaOH solution mixed with HA(group II). GroupⅠ was heated at 180 $^{\circ}C$ for 24, 48, and 72 hours. GroupⅡ was heated at 180 $^{\circ}C$ for 12, 24, and 36 hours. And the treated surfaces were evaluated by Scanning electron microscopy(SEM), Energy dispersive X-ray spectroscopy(EDS), X-ray photoelectron spectroscopy(XPS), X-ray diffraction method(XRD), Confocal laser scanning microscopy(CLSM). And SEM of fibroblast and 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) assay were used for cellular responses of the treated surfaces. Results. The color of surface changed in both groups after the hydrothermal process. SEM images showed that coating pattern was homogeneous in group II, while inhomogeneous in group I. H72 had rosette-like precipitates. The crystalline structure grew gradually in group II, according to extending treatment period. The long needle-like crystals were prominent in N36. Calcium(Ca) and phosphorus(P) were not detected in H24 and H48 in EDS. In all specimens of group II and H72, Ca was found. Ca and P were identified in all treated groups through the analysis of XPS, but they were amorphous. Surface roughness did not increase in both groups after hydrothermal treatment. The values of surface roughness were not significantly different between groups I and II. According to the SEM images of fibroblasts, cell attachments were oriented and spread well in both treated groups, while they were not in the control group. However, no substantial amount of difference was found between groups I and II. Conclusions. In this study during the hydrothermal process procedure, coating characteristics, including the HA precipitates, crystal growth, and crystalline phases, were more satisfactory in NaOH treated group than in HCl treated group. Still, the biological responses of the modified surface by this method were not fully understood for the two tested groups did not differ significantly. Therefore, more continuous research on the relationship between the surface features and cellular responses seems to be in need.