As popularity of dental implantation is increasing, the number of cases associated with complications also increase. Evaluation on diabetes mellitus is often neglected due to the disease's irrelevance to implantability. However, patients with diabetes mellitus are susceptible to infection due to impaired bactericidal ability of neutrophils, cellular immunity and activity of complements. Due to this established connection between diabetes mellitus and infection, a couple of cases were selected to present patients with diabetes mellitus with glycemic incontrollability, suffering from post-implantation dentigerous inter-fascial space abscess.
Abscess* ; Complement System Proteins ; Dental Implantation* ; Dental Implants* ; Diabetes Mellitus* ; Humans ; Immunity, Cellular ; Klebsiella pneumoniae ; Neutrophils

PURPOSE: To evaluate the effect of light-curing on the immediate and delayed micro-shear bond strength (microSBS) between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and RelyX Ultimate when using Single Bond Universal (SBU). MATERIALS AND METHODS: Y-TZP ceramic specimens were ground with #600-grit SiC paper. SBU was applied and RelyX Ultimate was mixed and placed on the Y-TZP surface. The specimens were divided into three groups depending on whether light curing was done after adhesive (SBU) and resin cement application: uncured after adhesive and uncured after resin cement application (UU); uncured after adhesive, but light cured after resin cement (UC); and light cured after adhesive and light cured resin cement (CC). The three groups were further divided depending on the timing of microSBS testing: immediate at 24 hours (UUI, UCI, CCI) and delayed at 4 weeks (UUD, UCD, CCD). microSBS was statistically analyzed using one-way ANOVA and Student-Newman-Keuls multiple comparison test (P<0.05). The surface of the fractured Y-TZP specimens was analyzed under a scanning electron microscope (SEM). RESULT: At 24 hours, microSBS of UUI group (8.60+/-2.06 MPa) was significantly lower than UCI group (25.71+/-4.48 MPa) and CCI group (29.54+/-3.62 MPa) (P<0.05). There was not any significant difference between UCI and CCI group (P>0.05). At 4 weeks, microSBS of UUD group (24.43+/-2.88 MPa) had significantly increased over time compared to UUI group (P<0.05). The SEM results showed mixed failure in UCI and CCI group, while UUI group showed adhesive failure. CONCLUSION: Light-curing of universal adhesive before or after application of RelyX Ultimate resin cement significantly improved the immediate microSBS of resin cement to air-abrasion treated Y-TZP surface. After 4 weeks, the delayed microSBS of the non-light curing group significantly improved to the level of light-cured groups.
Adhesives* ; Ceramics* ; Resin Cements

PURPOSE: In osteoclast differentiation, actin-rich membrane protrusions play a crucial role in cell adhesion. Odontogenic ameloblast-associated protein (Odam) contributes to cell adhesion by inducing actin rearrangement. Odam-mediated RhoA activity may play a significant role in multinucleation of osteoclasts. However, the precise function of Odam in osteoclast cell adhesion and differentiation remains largely unknown. Here, we identify a critical role for Odam in inducing osteoclast adhesion and differentiation. MATERIALS AND METHODS: The expression of Odam in osteoclasts was evaluated by immunohistochemistry. Primary mouse bone marrow and RAW264.7 cells were used to test the cell adhesion and actin ring formation induced by Odam. RESULT: Odam was expressed in osteoclasts around alveolar bone. Odam transfection induced actin filament rearrangement and cell adhesion compared with the control or collagen groups. Overexpression of Odam promoted actin stress fiber remodeling and cell adhesion, resulting in increased osteoclast fusion. CONCLUSION: These results suggest that Odam expression in primary mouse osteoclasts and RAW264.7 cells promotes their adhesion, resulting in the induction of osteoclast differentiation.
Actin Cytoskeleton ; Actins* ; Animals ; Bone Marrow ; Cell Adhesion ; Collagen ; Immunohistochemistry ; Membranes ; Mice ; Osteoclasts* ; Stress Fibers ; Transfection

PURPOSE: Parathyroid hormone (PTH) therapy has drawn attention, as an alternative to anti-resorptive drugs since PTH accelerates bone density by anabolic action. The purpose of this study was to identify the effect of intermittent PTH administration on jaw bones of rat undergone bilateral ovariectomy. MATERIALS AND METHODS: Nine female Sprague-Dawley rats were divided into three groups. PTH group was ovariectomized (OVX) to induce osteoporosis and PTH 30 microg/kg was administered 1 week after the surgery. In OVX group, ovariectomy was performed and only vehicle was administered by subcutaneous injection 3 times per week. Control group was subjected to sham surgery. The animals were sacrificed 8 weeks after the surgery and specimens were obtained from ilium and upper and lower jaw bones. Histological investigation was carried out by using an optical microscope and micro-computed tomography was taken to examine structural property changes in each bone sample. RESULT: In the ilium, the bone volume ratio (bone volume/total volume, BV/TV) of PTH, OVX and control groups was 53.75%+/-7.57%, 50.61%+/-12.89%, 76.20%+/-5.92% (P=0.061) and bone mineral density (BMD) was 1.12+/-0.09, 0.88+/-0.48, 1.38+/-0.07 g/cm3 (P=0.061). In the mandible, BV/TV of PTH, OVX and control groups was 64.60%+/-12.17%, 58.26%+/-9.63%, 67.54%+/-14.74% (P=0.670) and BMD was 1.21+/-0.17, 1.19+/-0.13, 1.27+/-0.18 g/cm3 (P=0.587). In the maxilla, BV/TV of PTH, OVX and control groups was 61.19%+/-8.92%, 52.50%+/-11.22%, 64.60%+/-12.17% (P=0.430) and BMD was 1.20+/-0.11, 1.11+/-0.16, 1.21+/-0.17 g/cm3 (P=0.561). No statistically significant difference was found in any variables in all groups. Histological observation revealed that the ilium in OVX group demonstrated sparsely formed trabecular bones compared with other groups. However, upper and lower trabecular bones did not present significant differences. CONCLUSION: Intermittent administration of PTH appears to affect the microstructure of rat jaw bones, but statistical significance was not found. However, the measurements in this study partly implicated the possible anabolic effect of PTH in vivo.
Anabolic Agents ; Animals ; Bone Density ; Female ; Humans ; Ilium ; Injections, Subcutaneous ; Jaw* ; Mandible ; Maxilla ; Osteoporosis ; Ovariectomy ; Parathyroid Hormone* ; Rats* ; Rats, Sprague-Dawley

PURPOSE: This study was conducted to determine cell viability and differentiation capability of human periodontal ligament (PDL) cells and to elucidate the effects of cryopreservation on the activity of human third molar PDL cells by comparing PDL cells with and without cryopreservation. MATERIALS AND METHODS: Human PDL fibroblasts obtained from immature third molars were cultured and divided into two groups. The experimental group was cryopreserved with a slow freezing rate of 0.5degrees C/min from 4degrees C to -35degrees C followed by plunging in liquid nitrogen at -196degrees C and cultured after fast thawing. The control group was cultured without cryopreservation. Cell viability, growth capacity and morphology were evaluated in both groups. Bivariate statistics were used to compare 2 groups and linear mixed model analysis was used to investigate the growth trends difference over time. RESULT: Cell viability and growth capacity were not significantly different between the 2 groups (P>0.05). Cultured cell of both groups showed fibroblast-like in appearance, and there were no significant differences in morphology between 2 groups. The mixed model analysis revealed no significant difference of growth capacity between 2 groups over time (beta=-0.0009; P=0.138). CONCLUSION: This study demonstrates that cryopreservation under control does not affect the biological properties of PDL cells, supporting the feasibility of autotransplantation of cryopreserved impacted third molars.
Autografts ; Cell Survival ; Cells, Cultured ; Cryopreservation* ; Fibroblasts ; Freezing ; Humans* ; Molar, Third* ; Nitrogen ; Periodontal Ligament*

PURPOSE: The effect of accelerated aging on color stability of various dual-cured self-adhesive resin cements were evaluated in this study. MATERIALS AND METHODS: Color stability was examined using three different brands of dual-cured self-adhesive resin cements: G-CEM LinkAce (GC America), MaxCem Elite (Kerr), and PermaCem 2.0 (DMG) with the equivalent color shade. Each resin cement was filled with Teflon mold which has 6 mm diameter and 2 mm thickness. Each specimen was light cured for 20 seconds using light emitting diode (LED) light curing unit. In order to evaluate the effect of accelerated aging on color stability, color parameters (Commission Internationale de l'Eclairage, CIE L*, a*, b*) and color differences (DeltaE*) were measured at three times: immediately, after 24 hours, and after thermocycling. The L*, a*, b* values were analyzed using Friedman test and DeltaE* values on the effect of 24 hours and accelerated aging were analyzed using t-test. These values were compared with the limit value of color difference (DeltaE*=3.7) for dental restoration. One-way ANOVA and Scheff's test (P<0.05) were performed to analyze each DeltaE* values between cements at each test period. RESULT: There was statistically signifi cant difference in comparison of color specifi cation (L*, a*, b*) values after accelerated aging except L* value of G-CEM LinkAce (P<0.05). After 24 hours, color difference (DeltaE*) values were ranged from 2.47 to 3.48 and L* values decreased and b* values increased in all types of cement and MaxCem Elite had high color stability (P<0.05). After thermocycling, color change's tendency of cement was varied and color difference (DeltaE*) values were ranged from 0.82 to 2.87 and G-CEM LinkAce had high color stability (P<0.05). CONCLUSION: Color stability of dual-cured self-adhesive resin cements after accelerated aging was evaluated and statistically significant color changes occurred within clinically acceptable range.
Aging* ; Fungi ; Polytetrafluoroethylene ; Resin Cements*

In case of loss of many teeth due to dental caries or periodontal disease, improvement of masticatory function and aesthetics can be obtained through implant treatment. However, if the patient does not have a normal intercondylar relationship, it is difficult to achieve an ideal occlusal relationship with only prosthetic treatment. In particular, oral reconstruction with orthodontic treatment or orthognathic surgery is necessary for patients with mandibular prognathism. However, if the posterior occlusion collapses due to severe caries or periodontal disease, orthognathic surgery may be difficult. The occlusal vertical stop is very important for the stability of the mandibular position during occlusal reconstruction through orthognathic surgery. The patient in this case had posterior occlusion collapsed due to the caries of a large number of posterior teeth, and showed mandibular prognathism and long face. We planned a full arch restoration with orthognathic surgery and extracted the hopeless teeth. To secure the vertical stop required for orthognathic surgery, the implant was placed before surgery. After the orthognathic surgery and the final prosthesis application, the results were satisfactory for the improvement of the aesthetics and the restoration of the masticatory function.
Dental Caries ; Dental Implants ; Esthetics ; Humans ; Malocclusion ; Malocclusion, Angle Class III ; Orthognathic Surgery* ; Periodontal Diseases ; Prognathism* ; Prostheses and Implants ; Tooth*

PURPOSE: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. MATERIALS AND METHODS: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures 5℃~55℃, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. RESULT: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. CONCLUSION: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.
Aging ; Denture, Partial, Fixed* ; Denture, Partial, Fixed, Resin-Bonded ; In Vitro Techniques* ; Mastication ; Methylene Blue ; Molar ; Tooth

PURPOSE: The purpose of this study was to evaluate the dental fear experienced among Korean adolescents and to identify the relevant factors. MATERIALS AND METHODS: In order to compare the level of dental fear depending on the subjects' previous experience, descriptive statistical analysis was performed. Gender- and grade-dependent evaluation was performed according to the presence of their previous dental visit and dental fear. Subjective oral health status was also investigated. In order to determine the factors affecting dental fear, logistic regression analysis was performed. RESULT: Among the total of 333 subjects who had experienced dental fear, females were found to experience 1.766 times greater dental fear than males (P=0.007). The worse subjective perception of their oral health was associated with increase in the experience of dental fear by 1.245-fold (P=0.047). CONCLUSION: The dental fear was likely to be formed during the visit to the dentist's office or through previous experience of dental treatment. Therefore in order to reduce the fear associated with dental treatment in adolescents, establishemnt of a proper environment in the dental clinic and a patient management program are necessitated.
Adolescent* ; Dental Anxiety* ; Dental Clinics ; Female ; Humans ; Logistic Models ; Male ; Oral Health

PURPOSE: The purpose of this study was to investigate the electrochemical characteristics of nanotubular Ti-25Nb-xZr ternary alloys for dental implant materials. MATERIALS AND METHODS: Ti-25Nb-xZr alloys with different Zr contents (0, 3, 7, and 15 wt.%) were manufactured using commercially pure titanium (CP-Ti), niobium (Nb), and zirconium (Zr) (99.95 wt.% purity). The alloys were prepared by arc melting in argon (Ar) atmosphere. The Ti-25Nb-xZr alloys were homogenized in Ar atmosphere at 1,000℃ for 12 hours followed by quenching into ice water. The microstructure of the Ti-25Nb-xZr alloys was examined by a field emission scanning electron microscope. The phases in the alloys were identified by an X-ray diffractometer. The chemical composition of the nanotube-formed surfaces was determined by energy-dispersive X-ray spectroscopy. Selforganized TiO₂ was prepared by electrochemical oxidation of the samples in a 1.0 M H₃PO₄+0.8 wt.% NaF electrolyte. The anodization potential was 30 V and time was 1 hour by DC supplier. Surface wettability was evaluated for both the metallographically polished and nanotube-formed surfaces using a contact-angle goniometer. The corrosion properties of the specimens were investigated using a 0.9 wt.% aqueous solution of NaCl at 36℃±5℃ using a potentiodynamic polarization test. RESULT: Needle-like structure of Ti-25Nb-xZr alloys was transform to equiaxed structure as Zr content increased. Nanotube formed on Ti-25Nb-xZr alloys show two sizes of nanotube structure. The diameters of the large tubes decreased and small tubes increased as Zr content increased. The lower contact angles for nanotube formed Ti-25NbxZr alloys surfaces showed compare to non-nanotube formed surface. The corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface showed longer the passive regions compared to non-treatment surface. CONCLUSION: It is confirmed that corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface has longer passive region compared to without treatment surface.
Alloys* ; Argon ; Atmosphere ; Corrosion ; Dental Implants* ; Freezing ; Ice ; Nanotubes ; Niobium ; Spectrum Analysis ; Titanium ; Water ; Wettability ; Zirconium