A study of growth factors, chondrogenic differentiation of mesenchymal stem cells and cell response by needle size differences in vitro

Purpose@#This aim of this study was to demonstrate growth factors that differentiate human mesenchymal stem cells into chondrocytes and to evaluate cell proliferation enhancement by needle size differences. @*Materials and Methods@#Human mesenchymal stem cells were cultured in chondrogenic medium supplemented with BMP-2, BMP-4, BMP-6, BMP-7, BMP-13, FGF-2, FGF-18, IGF-1, TGF-β1, TGF-β2, TGF-β3 and without growth factors for 14, 21, and 28 days. Then, the expression levels of SOX-5, SOX-6, SOX-9 and FOXO1A were comparatively analyzed. Human mesenchymal stem cells were inoculated into culture dishes using 18, 21, and 26 gauge (G) needles, and cell proliferation was measured after 24, 48, and 72 hours, respectively. @*Results@#In addition to the previously known FGF, IGF-1, and TGFβ1,the BMP family growth factors such as BMP-2, BMP-4, BMP-6, and BMP-7 increased the expression of chondrocyte differentiation genes SOX-5, SOX-6, SOX-9, and FOXO1A. At 48 hours, the 26G group, the smallest needle, showed significant cell proliferation improvement compared to the control group and the 18G group. At 72 hours, the 26G group, the smallest needle, showed significant increase in cell proliferation compared to the control group. @*Conclusion@#Through this study, growth factors with the ability to induce chondrocyte differentiation of human mesenchymal stem cells were investigated, and cell proliferation changes by needle size differences were determined.

Reliability of a chairside CAD-CAM surgical guide for dental implant surgery on the anterior maxilla: An in vitro study

PURPOSE@#. This study evaluated the reliability of the chair-side CAD-CAM surgical guide (CSG) in the anterior maxilla by comparing its accuracy with the laboratory 3D-printed surgical guide (3DSG) and manual surgical guide (MSG) concerning different levels of dentists' surgical experience. @*MATERIALS AND METHODS@#. Ten surgical guides of each type (MSG, 3DSG, and CSG) were fabricated on a control study model with missing right and left central incisors. Sixty implants were placed in 30 study models by two dentists (one inexperienced and one experienced) using three different types of surgical guides. Horizontal deviations at shoulder and at apex, vertical, and angular deviations were measured after superimposing the planned and placed implant positions in the software. Kruskal-Wallis and Mann-Whitney U tests were used to compare the accuracy of three types of surgical guides in each dentist group and the accuracy of each surgical guide between two dentists (α = .05). @*RESULTS@#. There were no significant differences in any deviations between CSG and 3DSG, apart from angular deviation, for both dentists’ groups. Moreover, both CSG and 3DSG showed no significant differences in accuracy between the two dentists (P > .05). In contrast, MSG demonstrated significant differences from CSG and 3DSG and a significant difference in accuracy between the two dentists (P < .05). @*CONCLUSION@#. CSG provides superior accuracy to MSG in implant placement in the maxillary anterior region and is comparable to 3DSG at different levels of surgical experience, while offering the benefits of shorter manufacturing time and reduced patient visits.

Treatment with upper complete denture and lower implant-fixed restorations on an elderly patient presenting fully edentulous maxilla and bilateral posterior edentulous mandible: a case report / 대한치과보철학회지

Stable posterior occlusal support is crucial for adequate masticatory function and facial aesthetics. In elderly patients over the age of 65, masticatory ability has a significant impact on nutritional intake and overall health. This case report presents a prosthetic treatment of an elderly patient with edentulous maxilla and bilateral posterior edentulous mandible. The upper jaw was restored with a complete denture to establish an ideal occlusal plane, and the three-dimensional positions of the mandibular implants were determined accordingly. The implants were placed through computer-guided implant surgery and were immediately loaded with fixed provisional restorations. The implant-fixed zirconia final restorations were inserted in the lower posterior region, and the occlusal surface of posterior artificial teeth in the upper denture was substituted with cobalt-chrome alloy to resist occlusal wear. The patient’s posterior occlusal support and masticatory function were promptly restored through this treatment process, and long-term stability against wear was also obtained.

Computer-guided implant surgery and immediate provisionalization by chair-side CAD-CAM: A case report / 대한치과보철학회지

This report demonstrates a method of generating a chair-side and computer-aided template for implant surgery based on the Top-Down and restoration-driven concept. Compared to the traditional CAD-CAM process which requires multiple steps to be taken between dental clinic and laboratory, this alternative procedure, VARO guide system (VARO Guide, CAD, Pre-Guide, VARO-mill, NeoBiotech, Seoul, South Korea) enables accurate and patient-friendly implant surgery as well as immediate provisional restoration in a single visit. First, bite-registration at centric jaw relation and CBCT were taken using the Pre-Guide. The CBCT data was then reorganized directly through the chair-side CAD, and we could determine the most appropriate 3-dimensional position of implant. The STL file was extracted and put into the chair-side CAM (VARO-mill) to fabricate a VARO. This surgical guide allowed the implants to be accurately positioned into the planned sites within an hour.

Effect and mechanism of chitosan-based nano-controlled release system on the promotion of cell cycle progression gene expression / 대한치과보철학회지

Purpose@#In our previous studies, application of trichloroacetic acid (TCA) to gingival fibroblasts or to canine palatal soft tissue was verified to alter the expression of several genes responsible for cell cycle progression. In order to confirm this effect in a system allowing sequential release of TCA and epidermal growth factor (EGF), expression of various cell cycle genes following the application of the agents, using hydrophobically modified glycol chitosan (HGC)-based nano-controlled release system, was explored in this study. @*Materials and methods@#HGCbased nano-controlled release system was developed followed by loading TCA and EGF. The groups were defined as the control (CON); TCA-loaded nano-controlled release system (EXP1); TCA- and EGF- individually loaded nano-controlled release system (EXP2). At 24- and 48 hr culture, expression of 37 cell cycle genes was analyzed in human gingival fibroblasts. Correlations and the influential genes were also analyzed. @*Results@#Numerous genes such as cyclins (CCNDs), cell division cycles (CDCs), cyclin-dependent kinases (CDKs), E2F transcription factors (E2Fs), extracellular signal-regulated kinases (ERKs) and other cell cycle genes were significantly up-regulated in EXP1 and EXP2. Also, cell cycle arrest genes of E2F4, E2F5, and GADD45G were up-regulated but another cell cycle arrest gene SMAD4 was down-regulated. From the multiple regression analysis, CCNA2, CDK4, and ANAPC4 were determined as the most influential factors on the expression of ERK genes. @*Conclusion@#Application of TCA and EGF, using the HGC-based nano-controlled sequential release system significantly up-regulated various cell cycle progression genes, leading to the possibility of regenerating oral soft tissue via application of the proposed system.

Analysis of cell survival genes in human gingival fibroblasts after sequential release of trichloroacetic acid and epidermal growth factor using the nano-controlled release system

Purpose@#This study was to determine the possible effects of trichloroacetic acid (TCA) and epidermal growth factor (EGF) through cell survival genes of the PI3K-AKT signaling pathway when applying an hydrophobically modified glycol chitosan (HGC)-based nanocontrolled release system to human gingival fibroblasts in oral soft tissue regeneration. @*Materials and Methods@#An HGC-based nano-controlled release system was produced, followed by the loading of TCA and EGF. The group was divided into control (CON), TCA-loaded nano-controlled release system (EXP1), and the TCA- and EGF- individually loaded nano-controlled release system (EXP2).A total for 29 genes related to the PI3K-AKT signaling pathway were analyzed after 48h of culture in human gingival fibroblasts.Real-time PCR, 1- way ANOVA and multiple regression analysis were performed. @*Results@#Cell survival genes were significantly upregulated in EXP1 and EXP2. From multiple regression analysis, ITGB1 was determined to be the most influential factor for AKT1 expression. @*Conclusion@#The application of TCA and EGF through the HGC-based nano-controlled release system can up-regulate the cell survival pathway.

Analysis of cell survival genes in human gingival fibroblasts after sequential release of trichloroacetic acid and epidermal growth factor using the nano-controlled release system

Purpose@#This study was to determine the possible effects of trichloroacetic acid (TCA) and epidermal growth factor (EGF) through cell survival genes of the PI3K-AKT signaling pathway when applying an hydrophobically modified glycol chitosan (HGC)-based nanocontrolled release system to human gingival fibroblasts in oral soft tissue regeneration. @*Materials and Methods@#An HGC-based nano-controlled release system was produced, followed by the loading of TCA and EGF. The group was divided into control (CON), TCA-loaded nano-controlled release system (EXP1), and the TCA- and EGF- individually loaded nano-controlled release system (EXP2).A total for 29 genes related to the PI3K-AKT signaling pathway were analyzed after 48h of culture in human gingival fibroblasts.Real-time PCR, 1- way ANOVA and multiple regression analysis were performed. @*Results@#Cell survival genes were significantly upregulated in EXP1 and EXP2. From multiple regression analysis, ITGB1 was determined to be the most influential factor for AKT1 expression. @*Conclusion@#The application of TCA and EGF through the HGC-based nano-controlled release system can up-regulate the cell survival pathway.

SB-locking method for keeping implant restorations mechanically in place using fiber post: A case report / 대한치과보철학회지

All the faculties at the prosthodontic department in Kyung Hee University Dental Hospital at Gangdong, have been implementing the Top-Down concept of treatment approach since 2006 in which the outcomes of the last prosthetic treatment are predicted in advance during the treatment planning stage of patients with dental tissue defects. Based on the Top-Down concept, this report is also an example of how the final prosthetic treatment was performed in advance before going into implant surgery for the missing teeth. Among the various methods of connecting implant fixture and restoration, the cement-retained method is relatively simple to manufacture restoration without being constrained by the angle of the implants placed, but difficult to remove remaining subgingival excess cement completely, and to detach it being when necessary. In the report, SB-locking method will be introduced which enables an aesthetic implant restoration without either a screw hole or residual excess cement.

Analysis of the effect of trichloroacetic acid and epidermal growth factor release on cytoskeleton gene expression using the nano-controlled releasing system / 대한치과보철학회지

Purpose@#Here, we verified that the actin cytoskeletal gene expression of human gingival fibroblasts was altered by the administration of trichloroacetic acid (TCA) and epidermal growth factor (EGF) using the nano-controlled releasing system. @*Materials and methods@#The control and experimental groups were divided into 3 groups: the group with the TCA-only nano-controlled releasing system (EXP1), the group with the TCA- and EGF nano-controlled releasing system (EXP2), and the control group (CON) with 48-h incubation. Expression of 26 genes involved in the regulation of actin cytoskeleton were analyzed by real-time PCR followed by the determination of correlations and influential factors using the Pearson correlation analysis and multiple regression analysis. @*Results@#Among 23 genes upregulated in EXP1 and EXP2, expression of 14 genes were significantly increased in EXP2 compared to EXP1. On the other hand, LPAR1 was downregulated only in EXP1, GNA13 was upregulated only in EXP2, and F2R was downregulated only in EXP2. Three Rac1-related genes and CDC42 were identified as the influential factors of the actin gene upregulation. @*Conclusion@#The actin cytoskeleton genes in human gingival fibroblast were upregulated by the administration of TCA and EGF using HGC-based nano-controlled releasing system.

Oral Soft Tissue Regeneration Using Nano Controlled System Inducing Sequential Release of Trichloroacetic Acid and Epidermal Growth Factor

Background@#The effect of nano controlled sequential release of trichloroacetic acid (TCA) and epidermal growth factor (EGF) on the oral soft tissue regeneration was determined. @*Methods@#Hydrophobically modified glycol chitosan (HGC) nano controlled system was developed for the sequential release of TCA and EGF, and the release pattern was identified. The HGC-based nano controlled release system was injected into the critical-sized defects created in beagles’ palatal soft tissues. The palatal impression and its scanned body was obtained on various time points post-injection, and the volumetric amount of soft tissue regeneration was compared among the three groups: CON (natural regeneration control group), EXP1 (TCA-loaded nano controlled release system group), EXP2 (TCA and EGF individually loaded nano controlled release system). DNA microarray analysis was performed and various soft tissue regeneration parameters in histopathological specimens were measured. @*Results@#TCA release was highest at Day 1 whereas EGF release was highest at Day 2 and remained high until Day 3. In the volumetric measurements of impression body scans, no significant difference in soft tissue regeneration between the three groups was shown in two-way ANOVA. However, in the one-way ANOVA at Day 14, EXP2 showed a significant increase in soft tissue regeneration compared to CON. High correlation was determined between the histopathological results of each group. DNA microarray showed up-regulation of various genes and related cell signaling pathways in EXP2 compared to CON. @*Conclusion@#HGC-based nano controlled release system for sequential release of TCA and EGF can promote regeneration of oral soft tissue defects.

Oral Soft Tissue Regeneration Using Nano Controlled System Inducing Sequential Release of Trichloroacetic Acid and Epidermal Growth Factor

Background@#The effect of nano controlled sequential release of trichloroacetic acid (TCA) and epidermal growth factor (EGF) on the oral soft tissue regeneration was determined. @*Methods@#Hydrophobically modified glycol chitosan (HGC) nano controlled system was developed for the sequential release of TCA and EGF, and the release pattern was identified. The HGC-based nano controlled release system was injected into the critical-sized defects created in beagles’ palatal soft tissues. The palatal impression and its scanned body was obtained on various time points post-injection, and the volumetric amount of soft tissue regeneration was compared among the three groups: CON (natural regeneration control group), EXP1 (TCA-loaded nano controlled release system group), EXP2 (TCA and EGF individually loaded nano controlled release system). DNA microarray analysis was performed and various soft tissue regeneration parameters in histopathological specimens were measured. @*Results@#TCA release was highest at Day 1 whereas EGF release was highest at Day 2 and remained high until Day 3. In the volumetric measurements of impression body scans, no significant difference in soft tissue regeneration between the three groups was shown in two-way ANOVA. However, in the one-way ANOVA at Day 14, EXP2 showed a significant increase in soft tissue regeneration compared to CON. High correlation was determined between the histopathological results of each group. DNA microarray showed up-regulation of various genes and related cell signaling pathways in EXP2 compared to CON. @*Conclusion@#HGC-based nano controlled release system for sequential release of TCA and EGF can promote regeneration of oral soft tissue defects.

Complete denture made with closed-mouth impression technique on severely atrophied edentulous jaw / 대한치과보철학회지

At the department of prosthodontics, the elderly patients with severely atrophied alveolar ridge who have been wearing complete dentures for a long period frequently visit the clinic. In general, the open-mouth impression technique for manufacturing a mandibular complete denture to secure primary support on buccal shelf area has been prevalent. In addition, for securing retention and stability of mandibular denture, we should consider diagnosis, oral function, denture border, occlusal plane, teeth arrangement, and patient training, etc.. But in edentulous patients with severe alveolar bone atrophy, it may hardly secure retention and stability of mandibular complete denture. To promote these, some of clinicians are making an attempt manufacturing the mandibular complete dentures using closed-mouth impression technique based on several reports that compare various impression techniques including open-mouth and closed-mouth impression technique. This case report suggests closed-mouth impression technique may promote retention and stability of mandibular complete denture and compares between the two impression techniques clinically.

Chemical Regeneration of Wound Defects: Relevance to the Canine Palatal Mucosa and Cell Cycle Up-Regulation in Human Gingival Fibroblasts

BACKGROUND: Trichloroacetic acid (TCA) is an agent widely applied in dermatology for skin regeneration. To test whether TCA can offer an advantage for the regeneration of oral soft tissue defects, the cellular events following TCA application were explored in vitro and its influence on the oral soft tissue wound healing was evaluated in a canine palate model.METHODS: The cytotoxicity and growth factor gene expression in human gingival fibroblasts were tested in vitro following the application of TCA at four concentrations (0.005%, 0.05%, 0.5% and 1%) with different time intervals (0, 3, 9 and 21 h). One concentration of TCA was selected to screen the genes differentially expressed using DNA microarray and the associated pathways were explored. TCA was injected in open wound defects of the palatal mucosa from beagle dogs (n = 3) to monitor their healing and regeneration up to day 16-post-administration.RESULTS: While the 0.5–1% concentration induced the cytoxicity, a significantly higher expression of growth factor genes was observed after 3 and 9 h following the 0.5% TCA application in comparison to other groups. DNA microarray analysis in 0.5% TCA group showed 417 genes with a significant 1.5-fold differential expression, involving pathways of cell cycle, FoxO signaling, p53 signaling, ubiquitin mediated proteolysis and cAMP signaling. In vivo results showed a faster reepithelialization of TCA-treated wounds as compared to spontaneous healingCONCLUSION: TCA promoted the healing and regeneration of oral soft tissue wound defects by up-regulating the cell cycle progression, cell growth, and cell viability, particularly at a concentration of 0.5%.

Implant treatment on anterior cross-bite of a patient who had orthognathic surgery 20 years ago / 대한치과보철학회지

Orthognathic surgery of skeletal Class III malocclusion improves oral function and facial appearance. The greater amount of skeletal discrepancy, the greater amount of teeth movement required for decompensation, and this often causes pathological changes in periodontal tissue especially in lower anterior dentition. We made a Top-Down treatment plan with personalized analysis using Face Hunter, Plane System and ARCUS Digma II, in order to resolve severe mobility and cross-bite of lower anterior teeth for 49-year-old female patient who had undergone orthognathic surgery 20 years ago due to skeletal Class III malocclusion and mandibular prognathism. Lower anterior teeth were extracted and alveoloplasty was done. After healing of the wound, immediate loading was conducted immediately after implant placement. Final restorations were fabricated Zirconia using CAD/CAM, and inserted intraorally screw-retained type. During 6-month follow-up, no abnormal episodes of restorations were observed, and obtained satisfactorily both of functional and esthetic outcomes.

A case of removable dentures using digital method / 대한치과보철학회지

Generally dentures are manufactured by conventional method, however the frequency of fabricating denture using digital method is increasing due to the recent development of digital technology in dentistry. The digital method of manufacturing denture is classified into two systems; 3D scan of the impression to arrange the artificial teeth on the CAD (Computer-aided design) and 3D printing to produce the resin-based complete denture, or 3D scan of the model to design of the framework using CAD, resin pattern formation by 3D printing and casting of metal framework of complete denture or removable partial denture. In this case report, electronic surveying and design the metal framework of the dentures were performed using CAD program, and plastic resin patterns fabricated by 3D printing were casted for upper full denture and lower removable partial denture. During follow-up periods, dentures using digital method have provided satisfactory results esthetically and functionally.

The Effect of Fibronectin-Immobilized Microgrooved Titanium Substrata on Cell Proliferation and Expression of Genes and Proteins in Human Gingival Fibroblasts

BACKGROUND: We aimed to determine the effect of fibronectin (FN)-immobilized microgrooved titanium (Ti) on human gingival fibroblast proliferation, gene expression and protein expression. METHODS: Photolithography was used to fabricate the microgrooved Ti, and amine funtionalization (silanization) was used for FN immobilization on titanium surfaces. Cell proliferation, gene expression and protein expression were analyzed, followed by multiple regression analysis for determining the influential factors on cell proliferation. RESULTS: FN-immobilized microgrooved Ti significantly enhanced the fibroblast proliferation in various timelines of culture, among which a burst of fivefold increase is induced at 96 h of culture compared to that on the control smooth Ti. We suggest a presence of the synergistic promotion effect of microgrooves and FN immobilization on fibroblast proliferation. Through a series of analyses on the expression of various genes and proteins involved in cell adhesion and proliferation, cyclin-dependent kinase 6, cyclin D1, integrin α5, oncogene c-Src, osteonectin, paxillin and talin-2 were determined as influential factors on promoting fibroblast proliferation induced by FN-immobilized microgrooved Ti. CONCLUSION: FN-immobilized microgrooved Ti can act as an effective surface for enhancing fibroblast proliferation, and can be used for promoting soft tissue response on the connective tissue attachment zone of biomaterial surfaces.

Differences in percussion-type measurements of implant stability according to height of healing abutments and measurement angle / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. MATERIALS AND METHODS: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 – 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. RESULTS: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. CONCLUSION: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.

A new retaining method of cement-retained restoration with linguo-horizontal insertion of fiber post / 대한치과보철학회지

The retaining methods of implant prosthesis were classified into a screw-retained and a cement-retained type. A screw-retained prosthesis has many advantages, such as retrievability, preventing residual cement, while their disadvantages include the possibility of screw loosening and fracture, on the contrary advantages of cement-retained prosthesis are relatively low cost, but they are difficult to retrieve. To combine the advantages of both type, screw-cement retained prosthesis (SCRP) type have been introduced. But they still require ideal implant placement. So we introduce fiber post retained prosthesis without residual cement for preventing soft tissue trouble due to excessive cement.

Implant supported removable dental prosthesis with magnetic attachment in crossed occlusion: A case report / 대한치과보철학회지

When attempting to restore the oral function of a partially edentulous patient, there are a number of prosthetic treatment options available, depending on the structure of remaining teeth. For example, when only one set of maxillary and mandibular teeth are diagonally in place across from each other, it is difficult to gain stable occlusion. In this case, implants can be put in place at the corresponding edentulous area to achieve balance. By doing so, a stable occlusion can be achieved. For this case report, a patient with crossed occlusion after extraction was treated with maxillary RDP (removable dental prosthesis) and mandibular implant-supported RDP (removable dental prosthesis). Moreover, an implant fixture was placed under the posterior molar of the distal extension base diagonally across from the remaining maxillary teeth. Then, magnetic attachment was implemented. According to the patient who received the treatment, the result was functionally and aesthetically satisfactory.

Analysis of dimensions and shapes of maxillary and mandibular dental arch in Korean young adults

PURPOSE: The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults. MATERIALS AND METHODS: The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, incisor-1(st) molar distance, incisor-2(nd) molar distance, intercanine distance, inter-1(st) molar distance, and inter-2(nd) molar distance in both the maxillary and mandibular arch were measured using a three-dimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance. RESULTS: Arch lengths (IM2D, incisal-2(nd) molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter 2(nd) molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms. CONCLUSION: This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans.