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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) 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 Ra 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

Objective: 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 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. Material and methods: 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. Results: 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

Purpose: 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 therapy accompanying systemic antibiotics administration. Methods: 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. Results: 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. Conclusions: Non-surgical therapy combined with systemic antibiotics administration in GAgP patients is suggested to be an effective approach to enhance the periodontal health.

Purpose: 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 rotary instrument. Methods: 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. Results: 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. Conclusions: The Nd:YAG laser and the high speed rotary instruments seem to be effective for the esthetic treatment of gingival melanin hyperpigmentation.

This study investigated the surface characteristics and biocompatibility of phosphate ion (P)-incorporated titanium (Ti) surfaces hydrothermally treated with various concentrations 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

Introduction B-1 cells represent a specialized subset of B cells that are distinct from conventional B cells. The exact role of B-1 cells is still under investigation. The purpose of this study was to characterize B-1 cell-derived monoclonal antibodies and to examine the expression of costimulatory molecules (MHC class, B7.1 and B7.2) by splenic and peritoneum-derived (PerC) B cells to a different antigenic stimulation. Methods As presentation of antigens to T lymphocytes by B-1 cells is difficult to evaluate at the human level, we used inbred mice. We established hybridoma producing B-1 cell-derived monoclonal antibodies to characterize them to the exogenous and endogenous antigens. Expression of MHC Class, B7.1, and B7.2 by splenic and PerC B cells to a different antigenic stimulation was also evaluated by flow cytometric analysis. Results We established two B-1 cell-derived clones demonstrating similarity in their manner of polyreactivity and in terms of their dose-saturable response to the multiple antigens. Splenic and PerC B cells revealed a similar pattern of MHC expression. However, B7.1 and B7.2 were expressed higher in both B cells, while these were more pronounced in PerC B cells. Conclusion B-1 cell-derived monoclonal antibodies were characterized as polyreactive in nature to a panel of exogenous and endogenous antigens. Splenic and PerC B cells revealed a distinctive pattern in their mode of expressing costimulatory molecules when challenged by exogenous or endogenous antigens.

The biocompatibility of calcium ion (Ca)-incorporated Ti6Al4V alloy implants, produced by hydrothermal treatment using a Ca-containing solution, was investigated. The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, Auger electron spectroscopy, and stylus profilometry. The viability of MC3T3-E1 cells on Ca-incorporated machined Ti6Al4V surfaces with different oxide thicknesses was compared with that on untreated machined Ti6Al4V surfaces with MTT assay. The osteoconductivity of the Ca-incorporated Ti6Al4V implants was evaluated by removal torque testing and histomorphometric analysis after 6 weeks of implantation in rabbit tibiae. Our results show that hydrothermal treatment with a Ca-containing solution produced a crystalline CaTiO(3) layer on Ti6Al4V surfaces, and calcium ions were gradually incorporated throughout the oxide layer. After immersion in Hank's balanced salt solution, a considerable apatite deposition was observed on all surfaces of the Ca-incorporated samples. Significant increases in cell viability (p0.001), removal torque forces, and bone-to-implant contact values (p0.05) were observed for Ca-incorporated Ti6Al4V implants compared with those for untreated Ti6Al4V implants.

The effect of anodic oxide films produced by β-glycerophosphate (β-GP) and calcium acetate (CA) anodizing on osteoblast-like cell attachment and spreading were evaluated in this study. Anodic oxide films were produced in different conditions: Group 1, 0.02 M β-GP and 0.2 M CA; Group 2, 0.03 M β-GP and 0.2 M CA; Group 3, 0.03 M β-GP and 0.2 M CA. Anodic oxide surface was significantly rougher in comparison to the control untreated titanium surfaces, and the surface roughness and composition of phosphate and oxide increased as the concentration of β-GP was increased. There was no significant difference in the cell viability when cells were cultured on the control or anodized surface using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Scanning electron micrographs revealed more spread cells on the anodized surface than on the smooth control surface. In conclusion, we suggested that the positive effects of anodized surfaces produced by β-GP and CA on spreading of osteoblast-like cells may be the result of the difference of surface roughness and amount of Ca and P in the oxide layer.

The response of osteoblast-like cells cultured on blasted and/or acid etching surfaces and the influence of surface texture or microtopography on cell attachment, cell proliferation, and the gene expression of the osteoblastic phenotype using ROS 17/2.8 cell lines were evaluated. The blasted and/or acid etching surfaces were significantly rougher in comparison to machined and etched surfaces (p < 0.05). On X-ray diffraction analysis, titanium hydride (TiH2) was observed on the surface etched with a mixture of HCl-H2SO4 solution, whereas TiH2 was not observed on machined and blasted surfaces. After 24 h incubation, most of the cells of all the groups had a flattened, polygonal shape and were fully spread, exhibiting the onset of proliferation. The MTT assay showed a significant decrease on the blasted surface compared to the machined surface at 7 day culture (p < 0.05). The expression of osteopontin mRNA, α1 (I) collagen mRNA, and alkaline phosphatase mRNA on rough surfaces was higher than on the machined surfaces, and was highest on the blasted surface at day 7.

This study was performed to evaluate the effect of anorganic bone mineral (ABM) coated with Tetra-Cell Adhesion Molecule (T-CAM) for bone formation in rabbit calvarial defects and compare the capability of bone formation in ABM coated with T-CAM (ABM/T-CAM) to that in commercially available ABM coated with a synthetic peptide (P-15) which mimics the cell-binding domain of type I collagen, PepGen P-15TM. T-CAM composed of four cell adhesion molecules (RGD, PHSRN, EPDIM, and YH) was synthesized and ABM/T-CAM were prepared by absorbing T-CAM on ABM (OsteoGraf/N-300; Densply Friadent Ceramed Corp., USA). Two 9-mm diameter, full-thickness calvarial defects were made in each rabbit parietal bone and sixteen adult male rabbits were used in this experiment. The defects were reconstructed according to four treatment groups: unfilled, BM-grafted, PepGen P-15TM-grafted, and ABM/T-CAM-grafted. The animals were sacrificed at 2 and 4 weeks after surgery for histologic and histomorphometric evaluation. An active new bone formation were observed in the defects of ABM/T-CAM and PepGen P-15TM grafted groups at 2 and 4 weeks of healing in histologic observation. The results of histomorphometric analysis revealed higher new bone formation in ABM/T-CAM-grafted (14.62±0.6% at 2 weeks, 15.33±2.4% at 4 weeks) and PepGen P-15TM-grafted (12.46±1.0% at 2 weeks, 18.14±1.7% at 4 weeks) groups than in unfilled control (7.03±2.3% at 2 weeks, 8.71±3.4% at 4 weeks) and ABMgrafted (6.59±1.7% at 2 weeks, 9.25±0.8% at 4 weeks) groups at 2 and 4 weeks of healing with statistical significance (P

The objective of this study was to evaluate the biocompatibility and effects of the particulated and surface modified Ostrich eggshell (OES) as bone graft substitutes in healing of calvarial defects in rats. Additionally we compared the bone forming ability of the surface modified OES to that of BioCoral (Inoteb, France), which has the same chemical compositions as OES, calcium carbonate (CaCO3). Surface modified OES particles were fabricated by alkaline etching (microroughened-OES) and biomimetic calcium phosphate coating (CaP coated-OES). 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to evaluate cell viability at 1, 4, and 7days using ROS 17/2.8 cells, a rat osteosarcoma cell line. To evaluate the bone forming ability, surface modified OES and BioCoral were filled in the calvarial defects of fourteen adult male Sprague-Dawley rats. After 4 weeks of healing, animals were sacrificed and evaluated histologically and histomorphometrically. The MTT assay indicated the increases in viable cell numbers of all groups according to the time, and significantly increased cell numbers were observed on CaP coated-OES and BioCoral at 7 day (P

In this study, the effect of anodization following hydrothermal treatments on osteoblast cell attachment and proliferation were evaluated. The anodic oxide films produced in this study was observed to exhibit overlapping microporous structures with microprojections. In addition, the anodic oxide surfaces were significantly rougher in comparison to control untreated titanium (Ti) surfaces. Following hydrothermal treatments for 2 and 4 h, hydroxyapatite (HA) crystals were observed on anodic surfaces. Using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, no significant difference in the biocompatibility of the treated and untreated Ti surfaces was observed. However, scanning electron micrographs indicated rounded osteoblast cells on control and anodized Ti surfaces, with numerous microvilli after 6 h. In contract, cells cultured on hydrothermally treated surfaces after 6 h incubation were observed to exhibit polygonal shape, flattened, and fully spread. In addition, more cells were observed on Ti surfaces that were hydrothermally treated for 4 h as compared to Ti surfaces that were hydrothermally treated for 2 h. After culturing the cells for 24 h and 4 days, no significant difference was observed for cells cultured on all surfaces. It was concluded from this study that hydrothermally treated surfaces exhibited an effect on early osteoblast attachment.

Purpose This study aimed to evaluate the effects of a cetylpyridinium chloride (CPC) and tranexamic acid (TXA) mouth rinse on patients with gingivitis. Methods This randomized, placebo-controlled, double-blind, parallel-group, clinical trial included 45 healthy adults with gingivitis, who were randomized into 2 groups. The experimental group used a 0.05% CPC and 0.05% TXA mouth rinse, and the control group used a placebo mouth rinse. The following clinical indices were assessed at baseline, at 3 weeks, and at 6 weeks: the Turesky-Quigley-Hein plaque index (QHI), the Löe-Silness gingival index (GI), and bleeding on marginal probing (BOMP). The subjects used the mouth rinse during the experimental period for 20 seconds, 4–5 times daily (10 mL each time). Results There were no significant differences in the clinical indices between the groups at baseline. In the experimental group (CPC+TXA), a statistically significant improvement was evident in the QHI, GI, and BOMP at 3 and 6 weeks. These results were similar to those observed in the control group at 3 and 6 weeks, although the change in BOMP was not statistically significant in that group. At 6 weeks, the experimental group had a significantly lower mean score for the QHI than the control group. Conclusions This study demonstrated that a CPC and TXA mouth rinse exhibited significant antiplaque and anti-gingivitis efficacy, and had a positive effect on bleeding control when used daily for 6 weeks., Graphical Abstract

There is a reported gap between the relative satisfaction of the clinician and patient after a root coverage procedure. In addition, there may also be a disparity between objective esthetic evaluation tools and subjective satisfaction.This study included 58 sites in 31 patients who had undergone root coverage procedures. The percentage of root coverage and the root coverage esthetic score system were used as objective measurements. A questionnaire with a five-point ordinal scale was used for subjective evaluation. Initial recession depth and width, Miller classification, tissue biotype, treatment procedures, and follow-up periods were considered as associated factors.After a period of at least 6 months from the procedure, the patient-perceived outcome showed a better match with the root coverage esthetic scoring system than the percentage of root coverage alone. A lower value for objective outcome was obtained for a deeper gingival recession and higher Miller class, but the subjective outcome displayed a steady trend. All four esthetic results were at their lowest after an epithelialized free soft tissue graft.An esthetic outcome according to patient satisfaction was not always consistent with that determined by professional scoring. In addition, partial root coverage may be viewed as a positive outcome by patients and clinicians in cases of deep gingival recession and high Miller class.This study evaluates the esthetic outcome of root coverage procedures using an objective method, including the percentage of root coverage, root coverage esthetic scoring system, and subjective assessment by patient and clinician-based questionnaires. The results will be helpful for the understanding of the differences that exist in esthetic satisfaction.

Matrix GLA protein (MGP), a γ-carboxyglutamic acid (GLA)–rich, vitamin K–dependent and apatite-binding protein, is a regulator of hypertrophic cartilage mineralization during development. However, MGP is produced by both hypertrophic and immature chondrocytes, suggesting that MGP's role in mineralization is cell stage–dependent, and that MGP may have other roles in immature cells. It is also unclear whether MGP regulates the quantity of mineral or mineral nature and quality as well. To address these issues, we determined the effects of manipulations of MGP synthesis and expression in (a) immature and hypertrophic chondrocyte cultures and (b) the chick limb bud in vivo. The two chondrocyte cultures displayed comparable levels of MGP gene expression. Yet, treatment with warfarin, a γ-carboxylase inhibitor and vitamin K antagonist, triggered mineralization in hypertrophic but not immature cultures. Warfarin effects on mineralization were highly selective, were accompanied by no appreciable changes in MGP expression, alkaline phosphatase activity, or cell number, and were counteracted by vitamin K cotreatment. Scanning electron microscopy, x-ray microanalysis, and Fourier-transform infrared spectroscopy revealed that mineral forming in control and warfarin-treated hypertrophic cell cultures was similar and represented stoichiometric apatite. Virally driven MGP overexpression in cultured chondrocytes greatly decreased mineralization. Surprisingly, MGP overexpression in the developing limb not only inhibited cartilage mineralization, but also delayed chondrocyte maturation and blocked endochondral ossification and formation of a diaphyseal intramembranous bone collar. The results show that MGP is a powerful but developmentally regulated inhibitor of cartilage mineralization, controls mineral quantity but not type, and appears to have a previously unsuspected role in regulating chondrocyte maturation and ossification processes.

Purpose: The purpose of this study was to analyze the expression of inducible nitric oxide synthases (iNOS), tissue inhibitors of metalloproteinase (TIMP)-3, and TIMP-4 in the gingival tissues of periodontal patients with or without type 2 diabetes mellitus (DM). Methods: Depending on the patient’s systemic condition and clinical criteria of the gingiva, each gingival sample was classi fied into one of three groups. Sixteen clinically, systemically healthy patients (group 1), 16 periodontal patients (group 2), and 16 periodontal patients with DM (group 3) were included. Tissue samples in each group were collected, prepared, and analyzed by western blotting. Quantification of the relative amount of TIMP-3, TIMP-4, and iNOS was performed. Results: The expression levels of iNOS and TIMP-3 both increased in group 1, group 2, and group 3 in increasing order, and were significantly higher in both group 2 and group 3 as compared to group 1 (P < 0.05). The expression levels of TIMP-4 increased in the same order, but significantly increased in group 2 as compared to group 1, in group 3 as compared to group 1, and group 3 as compared to group 2 (P < 0.05). Conclusions: This study demonstrated that iNOS, TIMP-3, and TIMP-4 might be involved in the progression of periodontal inflammation associated with type 2 DM. It is thought that further study of these factors can be applied practically for the diagnosis and control of periodontitis in diabetics.

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 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.

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.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.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 (P0.05), but no statistical differences were found between the RBM/Mg and M implants except BIC% values in total lateral length.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.

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 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 (P0.05). The UFG and CG Ti-13Nb-13Zr alloys displayed significantly increased cellular attachment compared with CG Ti-6Al-4V alloy (P0.05). The UFG Ti-13Nb-13Zr supported better cell spreading and more numerous focal adhesions. ALP activity (P0.05) 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.

Objectives: 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 two different macrodesigns: donut shaped with a 300–400 μm 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 β-TCP (Cerasorb). Material and methods: 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. Results: 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

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 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.

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.

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 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 CaTiO3 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. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008

One strategy to improve implant osseointegration is to control the quality of the bone reaction at the implant-bone tissue interface using an implant coated with biologically active substances. The purpose of this study was to investigate the effect of a tetra-cell adhesion molecule (T-CAM) coating composed of 4 cell-adhesion molecules-an arginine-glycine-aspartic acid (RGD) sequence, a proline-histidine-serine-arginine-asparagine (PHSRN) sequence, a tyrosine-histidine sequence (YH), and a glutamic acid-proline-aspartic acid-isoleucine-methionine (EPDIM)-on the rough-surfaced titanium implant on peri-implant bone formation in the rabbit femur with poor local bone conditions and minimal primary stability.Seven T-CAM-coated (blasted/T-CAM) and uncoated (blasted) implants with a rough surface (hydroxyapatite-blasted; Ra = 1.8 microm) were placed in slightly oversized beds of the metaphyses of the right and left femurs of 7 New Zealand White rabbits with light tactile pressure, and minimal primary stability was obtained. To evaluate the effects of T-CAM coating on the peri-implant bone healing response, histomorphometric analysis was performed 8 weeks after surgery. The 2 groups were compared using the Student t test, with a significance level of P.05.Compared to uncoated blasted implants at 8 weeks of healing, the blasted/T-CAM implants showed a significantly greater amount of bone-implant contact (BIC; P.01) and new bone formation in the zones 0 to 100 microm and 0 to 500 microm lateral to the implant surface (P.05) in the medullary space.The T-CAM coating on the rough-surfaced titanium implants significantly enhanced peri-implant bone formation in rabbit femurs with poor local bone condition.

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.

Objective: The purpose of this study was to investigate the effects of a nanostructured calcium coating on the surfaces of blasted Ti implants on peri-implant bone formation in the rabbit tibiae. Material and methods: Threaded implants (3.75 mm in diameter, 6 mm in length) were roughened by hydroxyapatite (HA) blasting (control; blasted implants). The implants were then hydrothermally treated in a Ca-containing solution for 24 h to prepare Ca-incorporated Ti surfaces (experimental; blasted/Ca implants). Surface characterizations were performed by scanning electron microscopy and stylus profilometry before and after Ca coating. Forty-two implants (21 control and 21 experimental) were placed in the proximal tibiae of seven New Zealand White rabbits. Each rabbit received six implants. To evaluate the effects of the nanostructured Ca coating on the peri-implant bone-healing response, removal torque tests and histomorphometric analyses were performed 6 weeks after surgery. Results: The Ca coating did not significantly change the surface properties produced by blasting at the micron level. Histologically, active bone apposition was observed in the blasted/Ca implants in the marrow space. Compared with the blasted implants, the blasted/Ca implants showed significantly increased bone-to-implant contact over the total implant length (P

Periodontal ligament (PDL) cells are the most important cells in the healing of wounds and the regeneration of periodontal tissues. The response of PDL cells regarding cellular activity to high glucose concentration levels could be the key in understanding the events associated with the dental care of brittle diabetes. We studied the effect of high glucose concentration levels on the cellular activity of PDL cells from five non-diabetic patients in vitro. PDL cells were cultured for 14 days in a normal glucose medium (1100mg/l of glucose) or in a high glucose medium (4500mg/l of glucose) and a 3-(4,5-dimethylithiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for cellular viability was also performed. In order to evaluate the differentiation of PDL cells to osteoblast-like cells, mineralized nodule formation was induced with supplemented media containing 50microg/ml of ascorbic acid, 10mM of beta-glycerophosphate and 100nM of dexamethasone for 21 days. High glucose significantly inhibited the proliferation of PDL cells and reduced the optic density of the MTT assay. Concerning the mineralized nodule formation, the percentage of the calcified area to the total culture dish of PDL cells in high glucose level was lower than that in the normal glucose medium. In conclusion, high glucose inhibits the proliferation and differentiation of PDL cells. The data provide an explanation for the delayed periodontal regeneration and healing in diabetic patients.

Although fibroblast growth factor 2 (FGF2) and fibroblast growth factor receptor 3 (FGFR3) both inhibit longitudinal bone growth, little is known about the relationship between FGF2 and FGFR3. Accordingly, the current study examined the expression of FGFR3 mRNA after the administration of FGF2 using cultured chondrocytes from day 17 chick embryos to evaluate the relationship between FGF2 and FGFR3. The chondrocytes were isolated from the caudal one-third portion (LS) of sterna, peripheral regions (USP) and central core regions (USC) of the cephalic portion of the sterna, and lower portion of the proximal tibial growth plate (Ti) of day 17 chick embryo. The expression of FGFR1, FGFR3, and type II and X collagen mRNA in the chondrocytes from the LS, USP, USC, and Ti was determined. FGFR1 was not expressed in the LS and USP chondrocytes, yet strongly expressed in the USC and Ti chondrocytes. With a treatment of FGF2, the expression of FGFR1 slightly increased in the USC chondrocytes and was not related with the concentration of FGF2 in the Ti chondrocytes. FGFR3 was expressed in all the chondrocyte types, yet strongly increased in the LS, USC, USP, and Ti in that order according to the concentration of FGF2. For the LS and USP chondrocytes, the expression of FGFR3 with FGF2 increased in a 4-day culture, yet decreased in a 6-day culture, whereas for the USC chondrocytes, the expression of FGFR3 mRNA with FGF2 increased in a 2-day culture, yet decreased in a 4-day culture, suggesting that the hypertrophic chondrocytes were more numerous and sensitive compared to the proliferative chondrocytes. For all the chondrocyte types, FGF2 appeared to be up-regulated to FGFR3, as the expression of FGFR3 mRNA increased with a higher concentration of FGF2 until a peak level. In conclusion, FGF2 was found to up-regulate to FGFR3 until the peak level of FGFR3 mRNA expression, while in hypertrophic chondrocytes, FGFR3 appeared to cause the differentiaton of chondrocytes, resulting in the inhibition of longitudinal bone growth after the peak level of FGFR3 mRNA expression.

Purpose The purpose of the current study was to examine the effect of dexamethasone (Dex) at various concentrations on the apoptosis and mineralization of human periodontal ligament (hPDL) cells. Methods hPDL cells were obtained from the mid-third of premolars extracted for orthodontic reasons, and a primary culture of hPDL cells was prepared using an explant technique. Groups of cells were divided according to the concentration of Dex (0, 1, 10, 100, and 1,000 nM). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed for evaluation of cellular viability, and alkaline phosphatase activity was examined for osteogenic differentiation of hPDL cells. Alizarin Red S staining was performed for observation of mineralization, and real-time polymerase chain reaction was performed for the evaluation of related genes. Results Increasing the Dex concentration was found to reduce cellular viability, with an increase in alkaline phosphatase activity and mineralization. Within the range of Dex concentrations tested in this study, 100 nM of Dex was found to promote the most vigorous differentiation and mineralization of hPDL cells. Dex-induced osteogenic differentiation and mineralization was accompanied by an increase in the level of osteogenic and apoptosis-related genes and a reduction in the level of antiapoptotic genes. The decrease in hPDL cellular viability by glucocorticoid may be explained in part by the increased prevalence of cell apoptosis, as demonstrated by BAX expression and decreased expression of the antiapoptotic gene, Bcl-2. Conclusions An increase in hPDL cell differentiation rather than cellular viability at an early stage is likely to be a key factor in glucocorticoid induced mineralization. In addition, apoptosis might play an important role in Dex-induced tissue regeneration; however, further study is needed for investigation of the precise mechanism.

Purpose Under 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. Methods 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. Results 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). Conclusions 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.

Purpose: 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 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. There-fore, 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). Methods: To analyze the cell viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed, and to 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. Results: 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 Ca2+ 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. Conclusions: 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.

Purpose 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 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. Methods 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. Results 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. Conclusions 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.

1Periodontology and 2 Oral Biochemistry, Kyungpook National University School of Dentistry, Daegu, Korea Purpose: 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 gingival tissues of patients with chronic periodontitis accompanied with inflammatory reaction related to alveolar bone resorption with or without type 2 diabetes mellitus (DM). Methods: 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. Results: 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. Conclusions: 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.

Purpose: The purpose of this study was to observe and quantify the expression of interleukin-4 (IL-4), interferon-g (IFN-g), 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. Methods: 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. Results: The expression levels of IFN-g 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. Conclusions: The findings suggest that IFN- g 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.

Purpose: The purpose of this study was to quantify and compare the expressions of CRP and M-CSF in the gingival tis- sues of the patients with chronic periodontitis associated to hypertension. Methods: Gingival tissue samples were obtained during periodontal surgery or tooth extraction. Clinically healthy gingival tissue samples from systemically healthy 12 patients were categorized as group 1 (n=12). Inflammatory gingival tissue sam- ples from patients with chronic periodontitis were categorized as group 2 (n=12). Inflammatory gingival tissue samples from patients with chronic periodontitis associated with hypertension were categorized as group 3 (n=12). Tissue samples were prepared and analyzed by Western blotting. The quantification of CRP and M-CSF were performed using a densitometer and statistically analyzed by one-way ANOVA followed by Tukey test. Results: There were significant differences between group 1 and group 2 and between group 1 and group 3 in both CRP and M-CSF. The differences between group 2 and group 3 were not statistically significant in both proteins. However, the expression levels of CRP and M-CSF in hypertensive inflammatory gingiva showed increased tendency compared to non-hypertensive inflammatory gingiva. Conclusions: It is suggested that CRP and M-CSF might be used as inflammatory and bone resorption markers in perio- dontal diseased tissue. It is assumed that hypertension may be associated with the progression of periodontal inflammation and alveolar bone resorption. (J Korean Acad Periodontol 2009;39:391-398)

Purpose: The purpose of this report is to show three cases treated by an intergrated periodontal and restorative dentistry approach. Methods: Three patients with Miller Class gingiva recessions associated with cervical lesions were enrolled for treatment. Ⅰ Two patients received a connective tissue graft and resin modified glass ionomer, and one patient was treated with a con- nective tissue graft, resin restoration. Keratinized gingiva and relative gingival recession were measured. Results: The mean reduction of relative gingival recession was 3.7 mm, and the mean keratinized gingiva increase was 2.5 mm. The percentage of root coverage was 80% in average. No signs of gingival inflammation or bleeding on probing were seen. The patients were satisfied with the final esthetics and had no more dentin hypersensitivity. Conclusions: This report indicates that teeth with Miller Class gingival recession associated with cervical lesions can be Ⅰ successfully treated by a connective tissue graft combined with restorative dentistry. However, longitudinal randomized con- trolled clinical trials must be performed to support this approach. (J Korean Acad Periodontol 2009;39:437-441)

Purpose: The palatogingival groove is a developmental anomaly of the incisor teeth, which often presents severe localized periodontal disease. The purpose of this study was to evaluate the clinical outcome of palatogingival groove-associated pe- riodontal lesion following flap operation with glass ionomer filling. Methods: Four patients with periodontal lesion associated with the palatogingival groove were chosen for this case study. Clinical indices were taken and radiographic exam was performed at the baseline of the study and four patients were treat- ed by flap operation with GI filling. Post-surgical visits were scheduled at regular intervals to check clinical and radio- graphic changes. Results: Symptoms and signs of periodontal lesion were almost completely resolved with improvement of periodontal indices. Conclusions: Flap operation with direct glass ionomer restoration is thought to be an acceptable method which can produce favorable results in the treatment of periodontal lesion caused by palatogingival groove on the maxillary lateral incisor. (J Korean Acad Periodontol 2009;39:425-429)

Purpose: Deproteinized bovine bone substitutes are commonly used in dental regenerative surgery for treatment of alveolar defects. In this study, three different bovine bone minerals - OCS-B (NIBEC, Seoul, Korea), Bio-Oss (Geistlich - Pharma, Switzerland), Osteograft/N - 300 (OGN, Dentsply Friadent Ceramed. TN, USA) - were investigated to analyze the basic characteristics of commercially available bone substitutes. Methods: Their physicochemical properties were evaluated by scanning electron microscopy, energy dispersive X-ray spectrometer (EDS), surface area analysis, and Kjeldahl protein analysis. Cell proliferation and alkaline phosphatase (ALP) activity of human osteosarcoma cells on different bovine bone minerals were evaluated. Results: Three kinds of bone substitutes displayed different surface properties. Ca/P ratio of OCS - B shown to be lower than other two bovine bone minerals in EDS analysis. Bio-Oss had wider surface area and lower amount of residual protein than OCS - B and OGN. In addition Bio - Oss was proved to have lower cell proliferation and ALP activity due to lots of residual micro particles, compared with OCS - B and OGN. Conclusions: Based on the results of this study, three bovine bone minerals that produced by similar methods appear to have different property and characteristics. It is suggested that detailed studies and quality management is needed in operations for dental use and its biological effects on new bone formation. (J Korean Acad Periodontol 2009;39:149-156)

Purpose: Excessive gingival display and short clinical crowns due to altered passive eruptions are major concerns for a considerable number of patients visiting dental clinics. Altered passive eruptions could be corrected through various types of periodontal surgery conformable to a classification. 3 cases are reported here on the esthetic correction of altered passive eruption to evaluate results of crown lengthening procedure. Methods: Three patients whose major complaints were excessive gingival display and short teeth were picked out for this case study. Before treatment, clinical and radiological exam was performed to choose type of surgery. Thickness and width of keratinized gingiva was measured in all three patients then they were treated by surgical methods including flap operation and depigmentation under subsequent diagnosis. Results: Uneventful healing and stable gingival margin were observed in all three patients except recurrence of gingival pigmentation of one patient. Conclusions: The treatment of altered passive eruption requires precise diagnostic procedure and could achieve better esthetic outcomes when it is accompanied by other orthodontic and orthognathic treatment. (J Korean Acad Periodontol 2009;39:199-204 )

Purpose: There are numerous reports about the usefulness of antibiotics such as doxycycline or metronidazole in the conventional treatment for the patients with chronic periodontal diseases. However, seldom are the reports about effects of vitamins or nutraceuticals. The purpose of this study was to evaluate the effects of nutrient supplement including multiple vitamins and neutraceuticals with PRF-K2 from plants and seaweed in treatment of the patients with chronic periodontitis which is needed a nonsurgical or a surgical treatment by evaluating the clinical parameters and the gingival crevicular fluid volume. Methods: The systemically healthy and nonsmoking patients diagnosed with chronic periodontitis were divided into a nonsurgical group and a surgical group. They were also divided into the test group with nutrient supplements and the control group without nutrient supplements. In the nonsurgical group, the clinical parameters (probing depth, clinical attachment level, sulcus bleeding index, and plaque index) and the gingival crevicular fluid volume were checked on baseline, at 1 week, at 3 week and at 9 week after a supplement treatment. In the surgical group, the clinical parameters and the gingival crevicular fluid volume were also checked at 15 week after a surgical treatment. Results: In both nonsurgical and surgical groups, reduction of pocket depth and increment of clinical attachment level were revealed in the test group compared with the control group, but there was not statistically significant difference (p>0.05), and sulcus bleeding index was decreased with statistically significant difference (p

Purpose: The purpose of this study is to evaluate the long term clinical and radiographic outcome and stability after trans- plantation of third molar with complete root formation. Methods: The subjects were 31 teeth (male 17, female 14, aged 22-55, average 39.9 yr old) of 31 patients who visited the department of periodontics and passed more than two years after autotransplantation procedure and still under regular check up. Modified success criteria of Chamberlin and Goerig was applied to determine the success of autotransplantation. Results: Three out of 31 teeth failed and resulted 90.3% of success rate. When compared according to sex, 15 out of 17 teeth had succeeded in male, 13 out of 14 succeeded in female. When compared the success rate according to cause of ex- traction, tooth loss due to caries and root fracture had all succeeded but 3 out of 24 had failed in tooth loss due to periodontal disease. When compared according to donor teeth, 12 out of 14 maxillary third molars and 16 out of 17 man- dibular third molars had succeeded. Conclusions: In long term evaluation over two years, if appropriate surgical procedure and proper case selection is made, autotransplantation of the third molar with complete root formation can be the alternative choice that substitutes prosthetic or implant treatment and it is a functionally acceptable procedure. (J Korean Acad Periodontol 2009;39:431-435)

Purpose: Many clinical studies have reported that higher success rates are achieved with teeth that have immature roots than other autotransplanted teeth that have more immature root. However, based on date published recently, the success rate of auto- transplantation of teeth with complete root formation was higher. The purpose of this study was to examine the long term(2 to 6 years follow-up) success rate of autotransplantation of third molar with complete root formation and to discuss some conditions and prerequisites for success. Materials and Methods: 26 sites of 24 patients aged 26 to 55 (mean age 40.8) were autotransplanted with third molars with complete root formation. These cases were followed for 2 to 6 years after surgery. The success criteria included (1) no dis- comfort during functioning (2) absence of progressive root resorption and alveolar bone resorption. Result: Of 26 teeth 5 teeth were failed, therefore success rate is 81%(21/26 teeth). The results suggested that higher success rate is acquired from (1) extraction socket due to dental caries (2) mandibular recipient site (3) patient younger than 40 years old. Autotransplantation of third molar to replace molars with advanced periodontal disease also showed considerably high suc- cess rate(84%). Conclusion: With appropriate case selection, autotransplantation of third molar with complete root formation remains a viable alternative for replacing a missing molar tooth. (J Korean Acad Periodontol 2008;38:225-230)