Jo-Young Suh

Publications of Jo-Young Suh

• Increased new bone formation with a surface magnesium-incorporated deproteinized porcine bone substitute in rabbit calvarial defects.

  Authors: Jin-Woo Park, Hyuk-Jin Ko, Je-Hee Jang, Hochang Kang, Jo-Young Suh

  Journal of biomedical materials research. Part A. 03/2012; 100(4):834-40.

  This study investigated the effects of magnesium ion (Mg) incorporation into the surface of deproteinized porcine cancellous bone in the bone healing of rabbit calvarial defects with the expectationThis study investigated the effects of magnesium ion (Mg) incorporation into the surface of deproteinized porcine cancellous bone in the bone healing of rabbit calvarial defects with the expectation of utilizing the integrin-ligand binding enhancement effect of Mg, and compared its bone healing capacity with that of untreated porcine cancellous bone and deproteinized bovine bone (Bio-Oss). Hydrothermal treatment was performed to produce Mg-incorporated porcine bone using an alkaline Mg-containing solution. The surface morphology and chemical composition of the samples were investigated using scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray photoelectron spectroscopy. Defects 7 mm in diameter were created in the calvaria of 14 adult male New Zealand White rabbits and were filled with (1) untreated porcine bone (PB), (2) Bio-Oss, and (3) Mg-containing porcine bone (MG). The percentage of newly formed bone (NB%) was evaluated histomorphometrically at 2 and 4 weeks after implantation. Hydrothermal treatment resulted in a Mg-containing surface in porcine bone covered with nanostructures ∼100 nm in size. The MG group supported better new bone formation compared with the other groups. Osteoconductive new bone formation was observed in the central defect area in the MG group at an early healing time-point. Histomorphometric analysis revealed significantly greater NB% in the MG group when compared with the untreated PB and Bio-Oss groups at 4 weeks (p < 0.05). The Mg-incorporated porcine bone with surface nanostructures achieved rapid new bone formation in the osseous defects of rabbit calvaria compared with untreated xenografts of porcine and bovine origin. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.

• The relative effect of surface strontium chemistry and super-hydrophilicity on the early osseointegration of moderately rough titanium surface in the rabbit femur.

  Authors: Jin-Woo Park, Tae-Geon Kwon, Jo-Young Suh

  Clinical oral implants research. 03/2012;

  OBJECTIVE: It is unclear whether surface bioactive chemistry or hydrophilicity plays a more dominant role in the osseointegration of micro-structured titanium implants having the same surfaceOBJECTIVE: It is unclear whether surface bioactive chemistry or hydrophilicity plays a more dominant role in the osseointegration of micro-structured titanium implants having the same surface topography at the micrometer and submicrometer scales. To understand their comparative effect on enhancing the early osseointegration of micro-rough-surfaced implants, this study compared the bone healing-promoting effect of surface strontium (Sr) chemistry that has been shown in numerous studies to super-hydrophilicity in the early osseointegration of moderately rough-surfaced clinical oral implants (SLA(®) implant) in rabbit cancellous bone. MATERIAL AND METHODS: Hydrothermal treatment was performed to incorporate Sr ions into the surface of clinical SLA implants (SLA/Sr implant). The surface characteristics were evaluated by using field emission-scanning electron microscopy, X-ray photoelectron spectroscopy and optical profilometry. Twenty screw implants (10 control and 10 experimental) were placed in the femoral condyles of 10 New Zealand White rabbits. The early osseointegration of the SLA/Sr implant was compared with a chemically modified super-hydrophilic SLA implant (SLActive(®) implant) by histomorphometric and resonance frequency analysis after 2 weeks of implantation. RESULTS: The SLA/Sr and SLActive implants exhibited an identical surface topography and average R(a) values at the micron and submicron scales. The SLA/Sr implant displayed a high amount of surface Sr content (15.6 at.%). There was no significant difference in the implant stability quotient (ISQ) values between the two groups. However, histomorphometric analysis revealed a significantly higher bone-to-implant contact percentage in the SLA/Sr implants compared with the SLActive implants in rabbit cancellous bone (P < 0.01). CONCLUSION: The results indicate that the surface Sr chemistry surpasses the effect of super-hydrophilicity in promoting the early bone apposition of moderately rough Ti surface in cancellous bone.

• Surface characteristics and primary bone marrow stromal cell response of a nanostructured strontium-containing oxide layer produced on a microrough titanium surface.

  Authors: Jin-Woo Park, Youn-Jeong Kim, Je-Hee Jang, Jo-Young Suh

  Journal of biomedical materials research. Part A. 03/2012;

  Strontium (Sr) has been successfully used for the treatment of osteoporotic bone, increasing new bone formation while reducing bone resorption by stimulating proliferation and differentiation ofStrontium (Sr) has been successfully used for the treatment of osteoporotic bone, increasing new bone formation while reducing bone resorption by stimulating proliferation and differentiation of osteoblastic cells and inhibiting osteoclast function. In this study, Sr-incorporated Ti oxide layer was produced on clinically relevant osteoconductive implant surface, that is, a grit-blasted microrough Ti surface, by a simple hydrothermal treatment with the expectation of utilizing the osteoblast response enhancement effect of Sr for the future applications as a more osteoconductive surface of the permanent load-bearing endosseous implants, without altering the original microrough surface features of grit-blasted Ti at the micron-scale. This surface exhibits a hierarchical structure (i.e., a nanoscale surface architecture of the Sr-incorporated Ti oxide layer (SrTiO(3) ) imposed on micron-scale rough Ti structure) and Sr ion release into physiological solution. In vitro experiments using primary mouse bone marrow stromal cells (BMSCs) revealed that the hydrothermally produced SrTiO(3) coating promotes both the early and late cell response of BMSCs grown on a microrough Ti surface, with notably enhanced attachment, spreading, focal adhesion, alkaline phosphatase activity, and expression of critical integrins and osteoblastic phenotype genes. These results indicate that a hydrothermally produced SrTiO(3) coating improves the osteoconductivity of the microrough Ti surface by enhancing both the early and late cell response of BMSCs. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.

• Comparative study on the cellular activities of osteoblast-like cells and new bone formation of anorganic bone mineral coated with tetra-cell adhesion molecules and synthetic cell binding peptide.

  Authors: Hyeon-Seok Yu, Woo-Chang Noh, Jin-Woo Park, Jae-Mok Lee, Dong-Jun Yang, Kwang-Bum Park, Jo-Young Suh

  Journal of periodontal & implant science. 12/2011; 41(6):293-301.

  We have previously reported that tetra-cell adhesion molecule (T-CAM) markedly enhanced the differentiation of osteoblast-like cells grown on anorganic bone mineral (ABM). T-CAM comprises recombinantWe have previously reported that tetra-cell adhesion molecule (T-CAM) markedly enhanced the differentiation of osteoblast-like cells grown on anorganic bone mineral (ABM). T-CAM comprises recombinant peptides containing the Arg-Gly-Asp (RGD) sequence in the tenth type III domain, Pro-His-Ser-Arg-Asn (PHSRN) sequence in the ninth type III domain of fibronectin (FN), and the Glu-Pro-Asp-Ilu-Met (EPDIM) and Tyr-His (YH) sequence in the fourth fas-1 domain of βig-h3. Therefore, the purpose of this study was to evaluate the cellular activity of osteoblast-like cells and the new bone formation on ABM coated with T-CAM, while comparing the results with those of synthetic cell binding peptide (PepGen P-15). To analyze the cell viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed, andto analyze gene expression, northernblot was performed. Mineral nodule formations were evaluated using alizarin red stain. The new bone formations of each group were evaluated using histologic observation and histomorphometrc analysis. Expression of alkaline phosphatase mRNA was similar in all groups on days 10 and 20. The highest expression of osteopontin mRNA was observed in the group cultured with ABM/P-15, followed by those with ABM/T-CAM and ABM on days 20 and 30. Little difference was seen in the level of expression of collagen type I mRNA on the ABM, ABM/T-CAM, and ABM/P-15 cultured on day 20. There were similar growth and proliferation patterns for the ABM/T-CAM and ABM/P-15. The halo of red stain consistent with Ca(2+) deposition was wider and denser around ABM/T-CAM and ABM/P-15 particles than around the ABM particles. The ABM/T-CAM group seemed to have bone forming bioactivity similar to that of ABM/P-15. A complete bony bridge was seen in two thirds of the defects in the ABM/T-CAM and ABM/P-15 groups. ABM/T-CAM, which seemed to have bone forming bioactivity similar to ABM/P-15, was considered to serve as effective tissue-engineered bone graft material.

• Bone-added osteotome technique versus lateral approach for sinus floor elevation: a comparative radiographic study.

  Authors: Sung-Mi Kim, Jin-Woo Park, Jo-Young Suh, Dong-Seok Sohn, Jae-Mok Lee

  Implant dentistry. 11/2011; 20(6):465-70.

  The aim of this study was to evaluate and compare the radiographic results of bone-added osteotome sinus floor elevation (BAOSFE) and lateral approach sinus floor elevation techniques. The 43The aim of this study was to evaluate and compare the radiographic results of bone-added osteotome sinus floor elevation (BAOSFE) and lateral approach sinus floor elevation techniques. The 43 patients who had undergone implant procedure with either BAOSFE or lateral approach method on their maxillary molar edentulous area were included. Their dental records were confirmative and the radiographic-changes using orthopantomographs were consistently checked up during 2 years after the procedure (immediately after procedure and 6 months, 12 months, and 24 months after implant placement). The radiographic evaluation after 2 years of implantation with sinus elevation showed the significant amount of bone formation (6.75 mm for BAOSFE and 11.36 mm for lateral approach method). Largest amount of grafted height loss occurred during the first 6 months (62.8% of total amount of bone loss), but the resorption was minimal (1.35 mm for BAOSFE and 1.36 mm for lateral approach method) for overall 24 months. Long-term stability of graft height was achieved using both BAOSFE and lateral approach sinus floor elevation. Overall, graft height decreased gradually during 2 years after procedures, but the changes were minimal.

• Gene expression pattern during osteogenic differentiation of human periodontal ligament cells in vitro.

  Authors: Mi-Hye Choi, Woo-Chang Noh, Jin-Woo Park, Jae-Mok Lee, Jo-Young Suh

  Journal of periodontal & implant science. 08/2011; 41(4):167-75.

  Periodontal ligament (PDL) cell differentiation into osteoblasts is important in bone formation. Bone formation is a complex biological process and involves several tightly regulated gene expressionPeriodontal ligament (PDL) cell differentiation into osteoblasts is important in bone formation. Bone formation is a complex biological process and involves several tightly regulated gene expression patterns of bone-related proteins. The expression patterns of bone related proteins are regulated in a temporal manner both in vivo and in vitro. The aim of this study was to observe the gene expression profile in PDL cell proliferation, differentiation, and mineralization in vitro. PDL cells were grown until confluence, which were then designated as day 0, and nodule formation was induced by the addition of 50 µg/mL ascorbic acid, 10 mM β-glycerophosphate, and 100 nM dexamethasone to the medium. The dishes were stained with Alizarin Red S on days 1, 7, 14, and 21. Real-time polymerase chain reaction was performed for the detection of various genes on days 0, 1, 7, 14, and 21. On day 0 with a confluent monolayer, in the active proliferative stage, c-myc gene expression was observed at its maximal level. On day 7 with a multilayer, alkaline phosphatase, bone morphogenetic protein (BMP)-2, and BMP-4 gene expression had increased and this was followed by maximal expression of osteocalcin on day 14 with the initiation of nodule mineralization. In relationship to apoptosis, c-fos gene expression peaked on day 21 and was characterized by the post-mineralization stage. Here, various genes were regulated in a temporal manner during PDL fibroblast proliferation, extracellular matrix maturation, and mineralization. The gene expression pattern was similar. We can speculate that the gene expression pattern occurs during PDL cell proliferation, differentiation, and mineralization. On the basis of these results, it might be possible to understand the various factors that influence PDL cell proliferation, extracellular matrix maturation, and mineralization with regard to gene expression patterns.

• The influence of type 2 diabetes mellitus on the expression of inflammatory mediators and tissue inhibitor of metalloproteinases-2 in human chronic periodontitis.

  Authors: Jae-Bung Kim, Mi-Hwa Jung, Je-Yeol Cho, Jin-Woo Park, Jo-Young Suh, Jae-Mok Lee

  Journal of periodontal & implant science. 06/2011; 41(3):109-16.

  The purpose of this study was to compare and quantify the expression of C-reactive protein (CRP), matrix metalloproteinase (MMP)-14, and tissue inhibitor of metalloproteinases (TIMP)-2 in gingivalThe purpose of this study was to compare and quantify the expression of C-reactive protein (CRP), matrix metalloproteinase (MMP)-14, and tissue inhibitor of metalloproteinases (TIMP)-2 in gingival tissues of patients with chronic periodontitis accompanied with inflammatory reaction related to alveolar bone resorption with or without type 2 diabetes mellitus (DM). Twelve patients with type 2 DM and chronic periodontitis (group 3), twelve patients with chronic periodontitis (group 2), and twelve healthy individuals (group 1) were included in the study. Gingival tissue biopsies were collected from each patient and from healthy individuals at the time of periodontal surgery (including surgical crown lengthening) or tooth extraction. The concentrations of cytokines were determined by a western blot analysis. The expression levels of CRP and MMP-14 increased in group 2 and 3, and they were highest in group 3. The expressions of TIMP-2 also increased in group 2 and 3. This study demonstrated that the expression levels of CRP, MMP-14, and TIMP-2 might be inflammatory markers in periodontal inflamed tissue. It can be assumed that CRP, MMP-14, and TIMP-2 may be partly involved in the progression of periodontal inflammation associated to type 2 DM.

• Bone healing of commercial oral implants with RGD immobilization through electrodeposited poly(ethylene glycol) in rabbit cancellous bone.

  Authors: Jin-Woo Park, Kazuya Kurashima, Yusuke Tustusmi, Chang-Hyeon An, Jo-Young Suh, Hisashi Doi, Naoyuki Nomura, Kazuhiko Noda, Takao Hanawa

  Acta biomaterialia. 04/2011; 7(8):3222-9.

  Immobilization of RGD peptides on titanium (Ti) surfaces enhances implant bone healing by promoting early osteoblastic cell attachment and subsequent differentiation by facilitating integrin binding.Immobilization of RGD peptides on titanium (Ti) surfaces enhances implant bone healing by promoting early osteoblastic cell attachment and subsequent differentiation by facilitating integrin binding. Our previous studies have demonstrated the efficacy of RGD peptide immobilization on Ti surfaces through the electrodeposition of poly(ethylene glycol) (PEG) (RGD/PEG/Ti), which exhibited good chemical stability and bonding. The RGD/PEG/Ti surface promoted differentiation and mineralization of pre-osteoblasts. This study investigated the in vivo bone healing capacity of the RGD/PEG/Ti surface for biomedical application as a more osteoconductive implant surface in dentistry. The RGD/PEG/Ti surface was produced on an osteoconductive implant surface, i.e. the grit blasted micro-rough surface of a commercial oral implant. The osteoconductivity of the RGD/PEG/Ti surface was compared by histomorphometric evaluation with an RGD peptide-coated surface obtained by simple adsorption in rabbit cancellous bone after 2 and 4 weeks healing. The RGD/PEG/Ti implants displayed a high degree of direct bone apposition in cancellous bone and achieved greater active bone apposition, even in areas of poor surrounding bone. Significant increases in the bone to implant contact percentage were observed for RGD/PEG/Ti implants compared with RGD-coated Ti implants obtained by simple adsorption both after 2 and 4 weeks healing (P<0.05). These results demonstrate that RGD peptide immobilization on a Ti surface through electrodeposited PEG may be an effective method for enhancing bone healing with commercial micro-rough surface oral implants in cancellous bone by achieving rapid bone apposition on the implant surface.

• Osseointegration of commercial microstructured titanium implants incorporating magnesium: a histomorphometric study in rabbit cancellous bone.

  Authors: Jin-Woo Park, Chang-Hyeon An, Seong-Hwa Jeong, Jo-Young Suh

  Clinical oral implants research. 03/2011; 23(3):294-300.

  Objective: Recent studies have suggested that magnesium (Mg) ions exert a beneficial effect on implant osseointegration. This study assessed the osseointegration of nanoporous titanium (Ti) surfaceObjective: Recent studies have suggested that magnesium (Mg) ions exert a beneficial effect on implant osseointegration. This study assessed the osseointegration of nanoporous titanium (Ti) surface incorporating the Mg produced by hydrothermal treatment in rabbit cancellous bone to determine whether this surface would further enhance bone healing of moderately rough-surfaced implants in cancellous bone, and compared the result with commercially available micro-arc oxidized Mg-incorporated implants. Material and methods: The Mg-incorporated Ti surfaces (RBM/Mg) were obtained by hydrothermal treatment using an alkaline Mg-containing solution on grit-blasted moderately rough (RBM) implants. Untreated RBM and recently introduced Mg-incorporated microporous Ti implants produced by micro-arc oxidation (M) were used controls in this study. The surface characteristics were evaluated by scanning electron microscopy, X-ray photoelectron spectroscopy and optical profilometry. Twenty-four threaded implants with a length of 10 mm (eight RBM implants, eight RBM/Mg implants and eight M implants) were placed in the femoral condyles of 12 New Zealand White rabbits. Histomorphometric analysis was performed 4 weeks after implantation. Results: Hydrothermally treated and untreated grit-blasted implants displayed almost identical surface morphologies and R(a) values at the micron-scale. The RBM/Mg implants exhibited morphological differences compared with the RBM implants at the nano-scale, which displayed nanoporous surface structures. The Mg-incorporated implants (RBM/Mg and M) exhibited more continuous bone apposition and a higher degree of bone-to-implant contact (BIC) than the untreated RBM implants in rabbit cancellous bone. The RBM/Mg implants displayed significantly greater BIC% than untreated RBM implants, both in terms of the all threads region and the total lateral length of implants (P<0.05), but no statistical differences were found between the RBM/Mg and M implants except BIC% values in total lateral length. Conclusion: These results indicate that a nanoporous Mg-incorporated surface may be effective in enhancing the osseointegration of moderately rough grit-blasted implants by increasing the degree of bone-implant contact in areas of cancellous bone. To cite this article: Park J-W, An C-H, Jeong S-H, Suh J-Y. Osseointegration of commercial microstructured titanium implants incorporating magnesium: a histomorphometric study in rabbit cancellous bone. Clin. Oral Impl. Res. 23, 2012; 294-300. doi: 10.1111/j.1600-0501.2010.02144.x.

• Analysis of gene expression during mineralization of cultured human periodontal ligament cells.

  Authors: Hee-Dong Choi, Woo-Chang Noh, Jin-Woo Park, Jae-Mok Lee, Jo-Young Suh

  Journal of periodontal & implant science. 02/2011; 41(1):30-43.

  Under different culture conditions, periodontal ligament (PDL) stem cells are capable of differentiating into cementoblast-like cells, adipocytes, and collagen-forming cells. Several previous studiesUnder different culture conditions, periodontal ligament (PDL) stem cells are capable of differentiating into cementoblast-like cells, adipocytes, and collagen-forming cells. Several previous studies reported that because of the stem cells in the PDL, the PDL have a regenerative capacity which, when appropriately triggered, participates in restoring connective tissues and mineralized tissues. Therefore, this study analyzed the genes involved in mineralization during differentiation of human PDL (hPDL) cells, and searched for candidate genes possibly associated with the mineralization of hPDL cells. To analyze the gene expression pattern of hPDL cells during differentiation, the hPDL cells were cultured in two conditions, with or without osteogenic cocktails (β-glycerophosphate, ascorbic acid and dexamethasone), and a DNA microarray analysis of the cells cultured on days 7 and 14 was performed. Reverse transcription-polymerase chain reaction was performed to validate the DNA microarray data. The up-regulated genes on day 7 by hPDL cells cultured in osteogenic medium were thought to be associated with calcium/iron/metal ion binding or homeostasis (PDE1A, HFE and PCDH9) and cell viability (PCDH9), and the down-regulated genes were thought to be associated with proliferation (PHGDH and PSAT1). Also, the up-regulated genes on day 14 by hPDL cells cultured in osteogenic medium were thought to be associated with apoptosis, angiogenesis (ANGPTL4 and FOXO1A), and adipogenesis (ANGPTL4 and SEC14L2), and the down-regulated genes were thought to be associated with cell migration (SLC16A4). This study suggests that when appropriately triggered, the stem cells in the hPDL differentiate into osteoblasts/cementoblasts, and the genes related to calcium binding (PDE1A and PCDH9), which were strongly expressed at the stage of matrix maturation, may be associated with differentiation of the hPDL cells into osteoblasts/cementoblasts.

• Improved pre-osteoblast response and mechanical compatibility of ultrafine-grained Ti-13Nb-13Zr alloy.

  Authors: Chan Hee Park, Chong Soo Lee, Youn-Jeong Kim, Je-Hee Jang, Jo-Young Suh, Jin-Woo Park

  Clinical oral implants research. 12/2010; 22(7):735-42.

  Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessedMetallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti-13Nb-13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. The surface characteristics and mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti-13Nb-13Zr alloy were compared with coarse-grained (CG) Ti-13Nb-13Zr and CG Ti-6Al-4V alloys. Dynamic globularized Ti-13Nb-13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P<0.05). The UFG and CG Ti-13Nb-13Zr alloys displayed significantly increased cellular attachment compared with CG Ti-6Al-4V alloy (P<0.05). The UFG Ti-13Nb-13Zr supported better cell spreading and more numerous focal adhesions. ALP activity (P<0.05) and mRNA expressions of the osteoblast transcription factor genes (osterix, Runx2) and marker gene for osteoblast differentiation (osteocalcin) were markedly increased in cells grown on the UFG substrate compared with CG substrates at early incubation timepoints. Enhanced pre-osteoblast response to UFG Ti-13Nb-13Zr substrate is attributable to the non-cytotoxic alloying elements and the submicron scale grain size contributes to the superior surface hydrophilicity and abundant grain boundaries favorable for cell behavior. These findings indicate that dynamic globularized UFG Ti-13Nb-13Zr alloy is promising for load-bearing endosseous implant material because of excellent mechanical and biological compatibilites.

• Clinical case report on treatment of generalized aggressive periodontitis.

  Authors: Mi-Hwa Jung, Jin-Woo Park, Jo-Young Suh, Jae-Mok Lee

  Journal of periodontal & implant science. 10/2010; 40(5):249-53.

  The purpose of this study was to evaluate the improvement of periodontal health of generalized aggressive periodontitis (GAgP) diagnosed patients treated with non-surgical periodontal therapyThe purpose of this study was to evaluate the improvement of periodontal health of generalized aggressive periodontitis (GAgP) diagnosed patients treated with non-surgical periodontal therapy accompanying systemic antibiotics administration. Two patients with GAgP were chosen for this study. Clinical indices were taken and a radiographic examination was performed at the baseline of the study and they were treated by periodontal therapy accompanying systemic antibiotics administration. Post-surgical visits were scheduled at regular intervals to check clinical and radiographic changes. Through non-surgical periodontal therapy accompanying systemic antibiotics administration, GAgP patients showed decreased probing pocket depth, sulcus bleeding index, and increased attachment level and clinical index when comparing the initial and six month follow up data. In the six month follow-up radiographic examination after non-surgical periodontal therapy, resolution of the bony defect was observed. Non-surgical therapy combined with systemic antibiotics administration in GAgP patients is suggested to be an effective approach to enhance the periodontal health.

• Esthetic treatment of gingival melanin hyperpigmentation with a Nd:YAG laser and high speed rotary instrument: comparative case report.

  Authors: Hyuk-Jin Ko, Jin-Woo Park, Jo-Young Suh, Jae-Mok Lee

  Journal of periodontal & implant science. 08/2010; 40(4):201-5.

  The purpose of this study was to evaluate the clinical effectiveness of and patient's satisfaction with treatment of gingival melanin hyperpigmentation with a Nd:YAG laser and a high speed rotaryThe purpose of this study was to evaluate the clinical effectiveness of and patient's satisfaction with treatment of gingival melanin hyperpigmentation with a Nd:YAG laser and a high speed rotary instrument. Three patients with melanin hyperpigmentation in the anterior parts of the gingiva were chosen for this case study. Clinical photographs were taken at the preoperative state and three patients were treated under local anesthesia. In the maxilla, the gingival deepithelization was conducted with a high speed diamond bur, whereas, in the mandible with a Nd:YAG laser. Clinical photographs were taken immediately after the procedures and at the 1st, 2nd, and 4th week to evaluate clinical color changes. A week after the procedure, the patients filled out a questionnaire about any pain or discomfort. At the 4th week after the procedure, the patients filled out questionnaires about esthetic aspects of the results of treatment. In all cases, both anterior gingival areas were depigmented with satisfaction and the patients did not complain of severe pain or discomfort. At the 1st week of healing, the gingiva showed moderate to fast epithelization. Two weeks after the procedure, clinically, the gingiva showed almost complete healing. Four weeks after the procedure, there was significant improvement in gingival melanin hyperpigmentation. The Nd:YAG laser and the high speed rotary instruments seem to be effective for the esthetic treatment of gingival melanin hyperpigmentation.

• Healing of rabbit calvarial bone defects using biphasic calcium phosphate ceramics made of submicron-sized grains with a hierarchical pore structure.

  Authors: Jin-Woo Park, Eun-Suk Kim, Je-Hee Jang, Jo-Young Suh, Kwang-Bum Park, Takao Hanawa

  Clinical oral implants research. 03/2010; 21(3):268-76.

  This study investigated the efficacy of new bone graft substitutes - biphasic calcium phosphates (BCP) made of submicron-sized grains with fully interconnected wide-range micron-scale pores in twoThis study investigated the efficacy of new bone graft substitutes - biphasic calcium phosphates (BCP) made of submicron-sized grains with fully interconnected wide-range micron-scale pores in two different macrodesigns: donut shaped with a 300-400 microm central macropore (n-BCP-1) or rod-shaped (n-BCP-2)--in the healing of rabbit calvarial defects, and compared their bone-healing properties with those of various commercial bone substitutes, which included substitutes with similar BCP composition (MBCP and Osteon), anorganic bovine bone (Bio-Oss), and beta-TCP (Cerasorb). The surface morphology of the bone substitutes was investigated using scanning electron microscopy (SEM). Defects 8 mm in diameter were created in the calvaria of 30 adult male New Zealand White rabbits and were filled with six types of bone substitutes. The percentage of newly formed bone (NB%) was evaluated histomorphometrically 4 and 8 weeks after implantation. SEM observation showed submicron-sized grains with fully interconnected micropore structures in the n-BCP-1 and n-BCP-2 groups; these groups also showed considerable new bone formation in inner micropores as well as on the outer surfaces. The n-BCP-1 group exhibited enhanced new bone formation and direct ingrowth of bone tissue with blood vessels into central pores. Histomorphometric analysis showed significantly greater NB% in the n-BCP-1 group when compared with the other groups at 4 and 8 weeks (P<0.05). A new BCP ceramics made of submicron-sized grains with a hierarchical pore structure was an effective osteoconductive material for the treatment of osseous defects of rabbit calvaria.

• The expressions of inflammatory factors and tissue inhibitor of matrix metalloproteinase-2 in human chronic periodontitis with type 2 diabetes mellitus.

  Authors: Dong-Seok Shin, Jin-Woo Park, Jo-Young Suh, Jae-Mok Lee

  Journal of periodontal & implant science. 02/2010; 40(1):33-8.

  The purpose of this study was to observe and quantify the expression of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the gingivalThe purpose of this study was to observe and quantify the expression of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the gingival tissue of patients with type 2 diabetes mellitus (DM) and healthy adults with chronic periodontitis. Twelve patients with type 2 DM and chronic periodontitis (Group 3), twelve patients with chronic periodontitis (Group 2), and twelve healthy individuals (Group 1) were included in the study. Clinical criteria of gingival (sulcus bleeding index value, probing depths) and radiographic evidences of bone resorption were divided into three groups. The concentrations of cytokines were determined by a western blot analysis and compared using one-way ANOVA followed by Tukey's test. The expression levels of IFN-gamma and TIMP-2 showed an increasing tendency in Groups 2 and 3 when compared to Group 1. On the other hand, the expression of IL-4 was highest in Group 1. The findings suggest that IFN-gamma and TIMP-2 may be involved in the periodontal inflammation associated with type 2 DM. IL-4 may be involved in the retrogression of the periodontal inflammation associated with type 2 DM.

• Effects of phosphoric acid treatment of titanium surfaces on surface properties, osteoblast responses, and removal torque forces.

  Authors: Jin-Woo Park, Youn-Jeong Kim, Je-Hee Jang, Tae Geon Kwon, Yong Chul Bae, Jo-Young Suh

  Acta biomaterialia. 10/2009;

  This study investigated the surface characteristics and biocompatibility of phosphate ion (P)-incorporated titanium (Ti) surfaces hydrothermally treated with various concentration of phosphoric acidThis study investigated the surface characteristics and biocompatibility of phosphate ion (P)-incorporated titanium (Ti) surfaces hydrothermally treated with various concentration of phosphoric acid (H(3)PO(4)). The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, X-ray photoelectron spectroscopy, optical profilometry, contact angle and surface energy measurement, and inductively coupled plasma-mass spectroscopy (ICP-MS). MC3T3-E1 cell attachment, spreading, proliferation, and osteoblastic gene expression on different surfaces were evaluated. The degree of bony integration was biomechanically evaluated by removal torque testing after 4 weeks of healing in rabbit tibiae. The H(3)PO(4) treatment produced micro-rough Ti surfaces with crystalline P-incorporated Ti oxide layers. High concentration H(3)PO(4) treatment (1% and 2%) produced significantly higher hydrophilic surfaces compared with low H(3)PO(4) treatment (0.5%) and untreated surfaces (p < 0.01). ICP-MS analysis showed P ions were released from P-incorporated surfaces. Significant increased cell attachment (p < 0.05) and notably higher mRNA expressions of Runx2, alkaline phosphatase, osteopontin, and osteocalcin were observed in cells grown on P-incorporated surfaces compared with cells on untreated machined surfaces. P-incorporated surfaces showed significantly higher removal torque forces compared with untreated machined implants (p < 0.05). Ti surfaces treated with 2% H(3)PO(4) showed increasing tendencies in osteoblastic gene expression and removal torque forces compared with those treated with lower H(3)PO(4) concentrations or untreated surfaces. These results demonstrate that H(3)PO(4) treatment may improve the biocompatibility of Ti implants by enhancing osteoblast attachment, differentiation, and biomechanical anchorage.

• Bone formation with various bone graft substitutes in critical-sized rat calvarial defect.

  Authors: Jin-Woo Park, Je-Hee Jang, Sang-Ryul Bae, Chang-Hyeon An, Jo-Young Suh

  Clinical oral implants research. 05/2009; 20(4):372-8.

  OBJECTIVE: This histomorphometric study compared the efficacy of a new bone graft substitute (N-HA) derived from hen eggshell, consisted of submicron scale porous hydroxyapatite structure, in theOBJECTIVE: This histomorphometric study compared the efficacy of a new bone graft substitute (N-HA) derived from hen eggshell, consisted of submicron scale porous hydroxyapatite structure, in the healing of 8 mm diameter critical size defects in rat calvaria. We compared N-HA alone or in combination with calcium sulfate (CS), with a commercial bone substitute, anorganic bovine bone (Bio-Oss, BO).MATERIAL AND METHODS: Critical size defects were created in calvaria of 56 adult Sprague-Dawley rats. Animals were divided into four groups and treated with (1) unfilled defects, (2) N-HA grafts, (3) BO grafts and (4) N-HA/CS grafts. The percentage of new bone formed (NB%) was evaluated histomorphometrically after 6 and 12 weeks.RESULTS: The N-HA group exhibited more new bone formation compared with other groups at 6 and 12 weeks. Histomorphometric analysis showed greater NB% in N-HA group (11.2% at 4 weeks and 19.2% at 12 weeks) compared with those in unfilled (3.9% at 6 weeks and 6.4% at 12 weeks), BO-treated (6.4% at 6 weeks and 8.2% at 12 weeks) and N-HA/CS-treated (6.3% at 6 weeks and 12.6% at 12 weeks) groups. The N-HA group showed significant differences in NB% compared with unfilled group at 6 weeks (P=0.016), unfilled and BO-treated groups at 12 weeks (P=0.001). The addition of CS did not enhance the NB% compared with defects grafted with N-HA alone.CONCLUSION: N-HA was an osteoconductive bone substitute for treating osseous defects in critical size defects of rat calvaria.

• Effects of calcium ion incorporation on osteoblast gene expression in MC3T3-E1 cells cultured on microstructured titanium surfaces.

  Authors: Jin-Woo Park, Jo-Young Suh, Hyun-Ju Chung

  Journal of biomedical materials research. Part A. 08/2008; 86(1):117-26.

  The surface characteristics of a calcium ion (Ca)-incorporated titanium (Ti) surface, produced by hydrothermal treatment using an alkaline Ca-containing solution, and its effects on osteoblasticThe surface characteristics of a calcium ion (Ca)-incorporated titanium (Ti) surface, produced by hydrothermal treatment using an alkaline Ca-containing solution, and its effects on osteoblastic differentiation were investigated. MC3T3-E1 pre-osteoblastic cells were cultured on machined or grit-blasted Ti surfaces with and without Ca incorporation. The MTT assay was used to determine cell proliferation, and real-time PCR was used for quantitative analysis of osteoblastic gene expression. Hydrothermal treatment with a Ca-containing solution produced a crystalline CaTiO(3) nanostructure of approximately 100 nm in dimension, preserving original micron-scaled surface topographies and microroughness caused by machining, blasting, or blasting and etching treatments. After immersion in Hank's balanced salt solution, considerable apatite formation was observed on all surfaces of the Ca-incorporated samples. Significantly more cell proliferation was found on Ca-incorporated Ti surfaces than on untreated Ti surfaces (p < 0.001). Quantitative real-time PCR analysis showed notably higher alkaline phosphatase, osteopontin, and osteocalcin mRNA levels in cells grown on Ca-incorporated blasted surfaces than on other surfaces at an early time point. Thus, Ca incorporation may have a beneficial effect on osseointegration of microstructured Ti implants by accelerating osteoblast proliferation and differentiation during the early healing phase following implantation.

• Bone response to endosseous titanium implants surface-modified by blasting and chemical treatment: a histomorphometric study in the rabbit femur.

  Authors: Jin-Woo Park, Il-Sung Jang, Jo-Young Suh

  Journal of biomedical materials research. Part B, Applied biomaterials. 02/2008; 84(2):400-7.

  This study evaluated the effects of the addition of oxide structure with submicron-scale porous morphology on the periimplant bone response around titanium (Ti) implants with microroughened surfaces.This study evaluated the effects of the addition of oxide structure with submicron-scale porous morphology on the periimplant bone response around titanium (Ti) implants with microroughened surfaces. Hydroxyapatite-blasted Ti implants with (experimental) and without (control) a porous oxide structure produced by chemical treatment were investigated in a rabbit femur model. Surface characterizations and in vivo bone response at 4 and 8 weeks after implantation were compared. The experimental implants had submicron-scale porous surface structure consisted of anatase and rutile phase, and the original R(a) values produced by blasting were preserved. The histomorphometric evaluation demonstrated statistically significantly increased bone-to-implant contact (BIC) for experimental implants, both in the three best consecutive threads (p < 0.01) and all threads (p < 0.05) at 4 weeks. There was no remarkable difference in the BIC% or bone area percentage between the two groups at 8 weeks. The porous Ti oxide surface enhanced periimplant bone formation around the Ti implants with microroughened surfaces at the early healing stage. Based on the results of this study, the addition of crystalline Ti oxide surface with submicron-sized porous morphology produced by chemical treatment may be an effective approach for enhancing the osseointegration of Ti implants with microroughened surfaces by increasing early bone-implant contact.

• Evaluation of bone healing with eggshell-derived bone graft substitutes in rat calvaria: A pilot study.

  Authors: Jin-Woo Park, Sang-Ryul Bae, Jo-Young Suh, Dong-Hee Lee, Sang-Hyun Kim, Hyungjun Kim, Chong Soo Lee

  Journal of biomedical materials research. Part A. 12/2007;

  The purpose of this study was to investigate the potential effectiveness of a surface-modified natural calcium carbonate, hen eggshell (ES) as a bone graft substitute. The surface characteristics,The purpose of this study was to investigate the potential effectiveness of a surface-modified natural calcium carbonate, hen eggshell (ES) as a bone graft substitute. The surface characteristics, cell viability on, and osteoconductivity of, particulated ES with and without hydrothermal treatment in phosphate solutions were evaluated. Hydrothermal treatment partially converted ES to calcium-deficient hydroxyapatite (HA) with surface microstructure. MTT assay indicated higher osteoblast viability on surface-modified ES compared with a commercially available bone substitute, anorganic bovine bone (Bio-Oss, BO) (p < 0.001). Histological and histomorphometric analysis showed significantly greater new bone formation and mineralized bone-to-graft contact of surface-modified ES, especially with hydrothermally treated ES, compared with BO in 5-mm diameter calvarial defects in rats at 4 and 8 weeks of healing (p < 0.01). Complete bony bridging was more frequently found with hydrothermally treated ES. The results of this pilot study indicate the potential efficacy of surface-modified particulated hen eggshell as an osteoconductive bone substitute in a rat calvarial defect model. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.