An IoT-based aptasensor biochip for the diagnosis of periodontal disease.

Severe periodontitis affects nearly 1 billion individuals worldwide, highlighting the need for early diagnosis. Here, an integrated system consisting of a microfluidic chip and a portable point-of-care (POC) diagnostic device is developed using a polymethyl methacrylate (PMMA) chip fabrication and a three-dimensional printing technique, which is automatically controlled by a custom-designed smartphone application to routinely assess the presence of a specific periodontitis biomarker, odontogenic ameloblast-associated protein (ODAM). A sandwich-type fluorescence aptasensor is developed on a microfluidic chip, utilizing aptamer pair (MB@OD64 and OD35@FAM) selectively binding to target ODAM. Then this microfluidic chip is integrated into an automated Internet of Things (IoT)-based POC device, where fluorescence intensity, as a signal, from the secondary aptamer binding to ODAM in a sandwich-type binding reaction on the microfluidic chip is measured by a complementary metal oxide semiconductor (CMOS) camera with a 488 nm light-emitting diode (LED) excitation source. Obtained signals are processed by a microprocessor and visualized on a wirelessly connected smartphone application. This integrated biosensor system allows the rapid and accurate detection of ODAM within 30 min with a remarkable limit of detection (LOD) of 0.011 nM under buffer conditions. Clinical application is demonstrated by successfully distinguishing between low-risk and high-risk individuals with 100 % specificity. A strong potential in the translation of this fluorescence-based microfluidic aptasensor integrated with an IoT-based POC system is expected to be employed for non-invasive, on-site, rapid, and accurate ODAM detection, facilitating periodontitis diagnosis.

Precautions and possibilities in orthodontic treatment of periodontally compromised patients: Current recommendations.

OBJECTIVE: Orthodontic treatment plays a crucial role in achieving optimal dental esthetics and functional occlusion. However, when periodontally compromised patients are involved, additional precautions and considerations are critical. This article aims to provide up-to-date recommendations for the orthodontic treatment of periodontally compromised patients. CLINICAL CONSIDERATIONS: Comprehensive diagnosis of the patient's periodontal status, inherent malocclusion, and secondary malocclusion resulting from periodontal disease are essential for achieving optimal esthetics and functional occlusion. This can be facilitated through the use of a simplified checklist. Prior to orthodontic treatment, pre-existing periodontal diseases should be managed. Light and controlled forces should be used to minimize the risk of adverse effects on the periodontium, and any potential traumatic occlusion during tooth movement should be minimized. Furthermore, careful anchorage management is required, and proper application of temporary anchorage devices can significantly expand the scope of orthodontic treatment. Finally, treatment results are maintained by ongoing supportive periodontal therapy even during the retention period. CONCLUSIONS: This article presents clinical cases demonstrating the importance of accurate diagnosis in orthodontics and periodontics and the positive impact of orthodontic treatment on patients with pre-existing periodontal diseases. CLINICAL SIGNIFICANCE: An up-to-date orthodontic treatment protocol for periodontally compromised patients is presented.

Change in Maxillary Sinus Mucosal Thickness in Patients with Preoperative Maxillary Sinus Mucosal Thickening as Assessed by Otolaryngologists: A Retrospective Study.

Background and Objectives: Maxillary sinus pathologic conditions may increase the risk of complications during posterior maxillary sinus augmentation surgery. The purpose of this study was to evaluate the changes in participants with preoperative maxillary sinus mucosal thickening and to assess this factor as a preoperative risk indicator for sinusitis after maxillary dental implantation. Materials and Methods: We compared the preoperative and postoperative maxillary sinus mucosal thickness (MSMT), the distance between the maxillary sinus ostium and sinus floor (MOD), and the MSMT/MOD ratio. The participants were divided into three groups (sinus augmentation, bone grafting, and no grafting). Results: The mean preoperative MSMT was 4.3 ± 2.0 mm, and the mean MSMT/MOD ratio was 0.13 ± 0.05. No postoperative sinusitis was observed in these patients, including cases caused by anatomical variations. The mean postoperative MSMT was 4.5 ± 2.3 mm, and the mean postoperative MSMT/MOD ratio was 0.15 ± 0.06. There was no statistically significant difference between the groups at each time point (p > 0.05). Conclusions: The study found no significant change in MSMT at post-treatment evaluation, even when considering different subgroups. It underscores the importance of preoperative maxillary sinus radiographic assessments and collaboration between dentists and otolaryngologists for better outcomes in patients with preoperative maxillary sinus mucosal thickening.

Decreased GCF DEL-1 and increased GCF neutrophils with increasing probing pocket depth.

PURPOSE: Developmental endothelial locus-1 (DEL-1) plays a role in regulating neutrophil migration within the periodontium. The objective of this study was to evaluate the levels of DEL-1 in saliva and gingival crevicular fluid (GCF), as well as the number of neutrophils in patients with periodontitis. METHODS: Forty systemically healthy, non-smoking periodontitis patients participated in this study. Clinical periodontal parameters, including the plaque index, probing pocket depth (PPD), clinical attachment level, bleeding on probing, modified sulcular bleeding index, and marginal bone level, were measured. Levels of DEL-1, interleukin (IL)-1ß, IL-6, and IL-8 in unstimulated saliva samples, as well as DEL-1 in the GCF of 3 teeth from each participant, were assessed. Neutrophil counts in oral rinse and GCF samples were recorded. Spearman correlation coefficients were used to examine the correlation between protein levels, clinical parameters, and neutrophil quantities. Participants were divided into 2 age groups (those under 50 years and those 50 years or older) in order to investigate potential age-related differences. RESULTS: DEL-1 levels in the GCF showed a negative relationship with PPD (sum). Neutrophils in oral rinse samples were positively correlated with PPD, IL-8, and IL-1ß levels. Neutrophils in GCF exhibited a positive correlation with PPD (sum). Salivary DEL-1 levels showed correlations with IL-8 and IL-1ß, but not with the clinical parameters of periodontitis. CONCLUSIONS: The negative relationship observed between PPD and GCF DEL-1 levels is consistent with the proposed protective role of DEL-1.

Vitamin E Enhances Cell Viability and the Osteogenic Differentiation of Cell Spheroids Made of Gingiva-Derived Stem Cells.

Background and Objectives: Vitamin E is reported to expedite new bone formation in animal models, and this has led to a decrease in the time needed for treatment. In this study, human gingiva-derived stem cell-derived spheroids were examined to determine the effects of vitamin E on cell survival, osteogenic differentiation, and mineralization. Materials and Methods: Human gingiva-derived stem cells were used to create spheroids, which were then cultivated with vitamin E at doses of 0, 0.1, 1, 10, and 100 ng/mL. The morphological examination and the qualitative and quantitative vitality of the cells were assessed. Alizarin Red S staining and alkaline phosphatase activity assays were performed on days 7 and 14 to evaluate the osteogenic differentiation. The expression levels of RUNX2 and COL1A1 were assessed using a real-time polymerase chain reaction. Results: The addition of vitamin E did not appear to alter the spheroid's shape at the measured quantities without altering the diameter. During the culture time, the majority of the cells in the spheroids fluoresced green. Regardless of concentration, there were substantial increases in cell viability in the vitamin E-loaded groups on day 7 (p < 0.05). On day 14, the Alizarin Red S staining was statistically higher in the 1 ng/mL group compared to the unloaded control (p < 0.05). The addition of vitamin E to the culture enhanced the mRNA expression levels of RUNX2, OCN, and COL1A1 based on the real-time polymerase chain reaction data. Conclusions: We draw the conclusion that vitamin E may be used to promote the osteogenic differentiation of stem cell spheroids in light of these data.

Effects of Enamel Matrix Derivative on Cell Spheroids Made of Stem Cells Obtained from the Gingiva on Osteogenic Differentiation.

Background and Objectives: A derivative of the enamel matrix was used to speed up periodontal regeneration, including the formation of new cementum, alveolar bone, and periodontal ligament. In this study, human gingiva-derived stem cell-derived cell spheroids were used to assess the effects of an enamel matrix derivative on cell viability, osteogenic differentiation, and mineralization. Materials and Methods: Human gingiva-derived stem cells were used to create spheroids, which were then coupled with unloaded control groups and an enamel matrix derivative at a final concentration of 2.7, 27, 270, and 2700 µg/mL. The morphological examination of the created stem cell spheroids took place on days 1, 3, 5, and 7. The Live/Dead Kit assay was used to determine the qualitative viability of cells on days 3 and 7. Using the Cell Counting Kit-8, the quantitative vitality of the cell spheroids was assessed on days 1, 3, and 5. On days 7 and 14, alkaline phosphatase activity assays and Alizarin Red S staining were carried out to examine the osteogenic differentiation of the cell spheroids. RUNX2 and COL1A1 expression levels on days 7 and 14 were determined using real-time polymerase chain reaction. Results: The added enamel matrix derivative at the tested concentrations did not significantly alter the morphology of the applied stem cells' well-formed spheroids on day 1. On days 3 and 7, the majority of the spheroids' cells fluoresced green while they were being cultivated. Alkaline phosphatase activity data revealed a substantial rise in the 2700 µg/mL group on day 7 when compared to the unloaded control (p < 0.05). On days 7 and 14, calcium deposits were distinctly seen in each group. In the 27 and 2700 µg/mL groups, the treatment with the enamel matrix derivative resulted in noticeably higher values for the Alizarin Red S staining (p < 0.05). qPCR results showed that adding an enamel matrix derivative to the culture of the 27 µg/mL group raised the level of RUNX2 mRNA expression. Conclusions: These results lead us to the conclusion that a derivative of the enamel matrix may be used to promote osteogenic differentiation in stem cell spheroids.

Evaluation of health screening data for factors associated with peri-implant bone loss.

PURPOSE: Systemic health has a profound effect on dental treatment. The aim of this study was to evaluate peri-implant bone loss and health screening data to discover factors that may influence peri-implant diseases. METHODS: This study analyzed the panoramic X-rays of patients undergoing health screenings at the Health Promotion Center at Seoul St. Mary's Hospital in 2018, to investigate the relationship between laboratory test results and dental data. The patients' physical data, such as height, weight, blood pressure, hematological and urine analysis data, smoking habits, number of remaining teeth, alveolar bone level, number of implants, and degree of bone loss around the implant, were analyzed for correlations. Their associations with glycated hemoglobin, glucose, blood urea nitrogen (BUN), creatinine, and severity of periodontitis were evaluated using univariate and multivariate regression analysis. RESULTS: In total, 2,264 patients opted in for dental health examinations, of whom 752 (33.2%) had undergone dental implant treatment. These 752 patients had a total of 2,658 implants, and 129 (17.1%) had 1 or more implants with peri-implant bone loss of 2 mm or more. The number of these implants was 204 (7%). Body mass index and smoking were not correlated with peri-implant bone loss. Stepwise multivariate regression analysis revealed that the severity of periodontal bone loss (moderate bone loss: odds ratio [OR], 3.154; 95% confidence interval [CI], 1.175-8.475 and severe bone loss: OR, 7.751; 95% CI, 3.003-20) and BUN (OR, 1.082; 95% CI, 1.027-1.141) showed statistically significant predictive value. The severity of periodontitis showed greater predictive value than the biochemical parameters of blood glucose, renal function, and liver function. CONCLUSIONS: The results of this study showed that periodontal bone loss was a predictor of peri-implant bone loss, suggesting that periodontal disease should be controlled before dental treatment. Diligent maintenance care is recommended for patients with moderate to severe periodontal bone loss.

Aptamer duo-based portable electrochemical biosensors for early diagnosis of periodontal disease.

Recently, point-of-care tests (POCT) have gained much attention due to their convenient, fast, simple, and easy characteristics. For POCT, portability is an essential feature. In this study, we have successfully fabricated a portable mini-potentiostat. Using chronoamperometry, electrical signals of this portable mini-potentiostat were measured, and the analytical performance of electrochemical aptasensors was compared with a benchtop potentiostat. The electrochemical signals measured by mini-potentiostat can be displayed on the screen of a smartphone. To verify the analytical performance of this portable electrochemical aptasensor platform with a mini-potentiostat, two well-known model protein biomarkers, vaspin, a type 2 diabetes biomarker, and thrombin, a biomarker for pulmonary metastasis and cardiovascular disease, were confirmed to be detected by using corresponding aptamer duo. After solid verification of this portable electrochemical aptasensor platform, we have successfully implemented this portable mini-potentiostat system to develop a portable sandwich-type binding pair of aptamers-based electrochemical biosensor, which can diagnose periodontal disease by measuring ODAM biomarker. The linear range of this ODAM biosensor was 0 to 15 nM with a detection limit of 0.02 nM and 1 nM in buffer and saliva, respectively. The sensitivity of this biosensor has been greatly enhanced, compared to previously developed surface plasmon resonance (SPR) or lateral flow assay (LFA) based aptasensors. This study showed that this new portable aptamer duo-based biosensor is expected to diagnose the early stage of periodontal diseases from real samples, such as saliva or gingival crevicular fluid in a short time as a point-of-care (POC) testing.

Diesel exhaust particles increase nasal symptoms and IL-17A in house dust mite-induced allergic mice.

Diesel exhaust particles (DEPs), traffic-related air pollutants, are considered environmental factors adversely affecting allergic diseases. However, the immunological basis for the adjuvant effects of DEP in allergic rhinitis (AR) remains unclear. Therefore, this study aimed to investigate the effect of DEP exposure on AR using a mouse model. BALB/c mice sensitized to house dust mite (HDM) were intranasally challenged with HDM in the presence and absence of DEP. Allergic symptom scores, serum total and HDM-specific immunoglobulins (Igs), eosinophil infiltration in the nasal mucosa, cytological profiles in bronchoalveolar lavage fluid (BALF), and cytokine levels in the nasal mucosa and spleen cell culture were analyzed. Mice co-exposed to HDM and DEP showed increased allergic symptom scores compared with mice exposed to HDM alone. Reduced total IgE and HDM-specific IgE and IgG1 levels, decreased eosinophil infiltration in the nasal mucosa, and increased proportion of neutrophils in BALF were found in mice co-exposed to HDM and DEP. Interleukin (IL)-17A level was found to be increased in the nasal mucosa of the co-exposure group compared with that in the HDM-exposed group. The levels of IL-4, IL-13, interferon-γ, IL-25, IL-33, and TSLP expression showed no difference between the groups with and without DEP treatment. Increased expression of IL-17A in the nasal mucosa may contribute to DEP-mediated exacerbation of AR in HDM-sensitized murine AR model.

Effect of lipopolysaccharide and polyinosinic:polycytidylic acid in a murine model of nasal polyp.

Several factors, including bacterial and viral infections, have been associated with rhinosinusitis and nasal tissue remodelling that may result in nasal polyp formation. However, the potential role of bacterial or viral stimuli triggering polyp development is unclear. Here, we used lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid [poly(I:C)] in a murine model of allergic rhinosinusitis to compare different effects of bacterial- and virus-derived stimuli in the pathogenesis of nasal polyp formation. Briefly, BALB/c mice were sensitised and challenged with ovalbumin and staphylococcal enterotoxin, with or without LPS or poly(I:C), and the consequent histopathological profiles, cytokines, and systemic humoral responses were studied. While no significant differences in polyp formations and epithelial disruptions were observed among the experimental groups, the local cell recruitment patterns slightly differed in animals that received either LPS or poly(I:C). Additionally, the local immune environments generated by LPS or poly(I:C) stimulation varied. LPS stimulation induced a marked Th1/Th17 response and predominantly neutrophilic nasal polyp formations, whereas poly(I:C) induced a Th2-skewed environment in neutrophilic nasal polyp development. Overall, our findings show that both cell recruitment patterns and local immune environments induced by these two stimuli differ, which may have implications in the physiopathology of rhinosinusitis with nasal polyp.

Human Rhinovirus Infection Enhances the Th2 Environment in Allergic and Non-allergic Patients with Chronic Rhinosinusitis.

OBJECTIVES: This study was conducted to determine whether patients with allergic rhinitis might be more susceptible to human rhinovirus (HRV) infection and whether the effects of infection on the elicited immune responses are different in allergic and non-allergic patients with chronic rhinosinusitis (CRS). METHODS: Uncinate process tissues were obtained from 61 CRS patients (of whom 39 had allergies and 22 did not) and were infected with HRV-16 using an air-liquid interface organ culture system. The expression levels of programmed cell death-ligand (PD-L)1, PD-L2, intracellular adhesion molecule 1, interferon-gamma (IFN-γ), interleukin (IL)-4, IL-5, and IL-10 were evaluated in the infected nasal mucosa. RESULTS: The HRV infection rates were not significantly different between the allergy (74.4%) and non-allergy (72.7%) groups. In the allergy group, the expression of PD-L1 (P=0.013) and IL-10 (P=0.040) was significantly elevated in the HRV-infected tissues, and there was a strong correlation between PD-L1 and IL-10 (r=0.868, P<0.001). In contrast, infected tissues from the non-allergy group displayed increased levels of IL-4 (P=0.039), IL-5 (P=0.023), and IFN-γ (P=0.031), as well as an increased IL-4/IFN-γ ratio, after HRV infection (P=0.043). CONCLUSION: This study showed that HRV infection rates were similar in the nasal mucosa of patients with CRS regardless of the presence of allergic rhinitis. HRV infection enhanced the Th2 environment by modulating PD-L1 and PD-L2 expression levels in allergic mucosa and by increasing the IL-4/IFN-γ ratio in non-allergic mucosa.

Fibroblast growth factor-4 maintains cellular viability while enhancing osteogenic differentiation of stem cell spheroids in part by regulating RUNX2 and BGLAP expression.

Fibroblast growth factors (FGFs) are growth factors that were initially identified as proteins that stimulate fibroblast proliferation. The aim of the present study was to examine the effects of FGF-4 on the morphology, cellular viability and osteogenic differentiation of stem cell spheroids. Stem cell spheroids were generated using concave microwells in the presence of FGF-4 at concentrations of 0, 50, 100 and 200 ng/ml. Cellular viability was qualitatively assessed by a fluorometric live/dead assay using a microscope and quantitatively determined by using Cell Counting Kit-8. Furthermore, alkaline phosphatase activity and calcium deposition were determined to assess osteogenic differentiation. Reverse transcription-quantitative PCR (RT-qPCR) was performed to evaluate the mRNA expression levels of Runt-related transcription factor 2 (RUNX2) and bone γ-carboxyglutamate protein (BGLAP). Spheroidal shapes were achieved in the microwells on day 1 and a significant increase in the spheroid diameter was observed in the 200 ng/ml FGF-4 group compared with the control group on day 1 (P<0.05). The results regarding viability using Cell Counting Kit-8 in the presence of FGF-4 at 50, 100 and 200 ng/ml at day 1 were 98.0±2.5, 106.2±17.6 and 99.5±6.0%, respectively, when normalized to the control group (P>0.05). Furthermore, the alkaline phosphatase activity was significantly elevated in the 200 ng/ml group, when compared with the control group. The RT-qPCR results demonstrated that the mRNA expression levels of RUNX2 and BGLAP were significantly increased at 200 ng/ml. Therefore, the present results suggested that the application of FGF-4 maintained cellular viability while enhancing the osteogenic differentiation of stem cell spheroids, at least partially by regulating RUNX2 and BGLAP expression levels.

Salivary microbiota in periodontal health and disease and their changes following nonsurgical periodontal treatment.

PURPOSE: The aims of this study were to examine the salivary microbiota in conditions of periodontal health and disease and to explore microbial changes following nonsurgical periodontal treatment. METHODS: Non-stimulated saliva samples were collected from 4 periodontally healthy participants at baseline and from 8 patients with chronic periodontitis at baseline and 3 months following nonsurgical periodontal therapy. The V3 and V4 regions of the 16S rRNA gene from the DNA of saliva samples were amplified and sequenced. The salivary microbial compositions of the healthy participants and patients with periodontitis prior to and following nonsurgical treatment of periodontitis were compared based on the relative abundance of various taxa. RESULTS: On average, 299 operational taxonomic units were identified in each sample. The phylogenetic diversity in patients with periodontitis was higher than that in healthy participants and decreased following treatment. The abundance of the phylum Spirochaetes and the genus Treponema in patients with periodontitis was 143- and 134-fold higher than in the healthy control group, respectively, but decreased significantly following treatment. The species that were overabundant in the saliva of patients with periodontitis included the Peptostreptococcus stomatis group, Porphyromonas gingivalis, the Fusobacterium nucleatum group, Parvimonas micra, Porphyromonas endodontalis, Filifactor alocis, and Tannerella forsythia. The phylum Actinobacteria, the genus Streptococcaceae_uc, and the species Streptococcus salivarius group were more abundant in healthy participants than in those with periodontitis. There was a trend toward a decrease in disease-associated taxa and an increase in health-associated taxa following treatment. CONCLUSIONS: Our results revealed differences in the taxa of salivary microbiota between conditions of periodontal health and disease. The taxa found to be associated with health or disease have potential for use as salivary biomarkers for periodontal health or disease.

Effects of early detection of peritoneal catheter migration on clinical outcomes: 15-years experiences from a single centre.

AIM: Catheter migration is an important cause of catheter malfunction in peritoneal dialysis (PD). The purpose of this study was to investigate the effect of early detection of catheter migration on clinical outcomes. METHODS: A retrospective review of 135 consecutive patients initiating PD immediately following catheter insertion from 2002 to 2017 was undertaken. In order to detect catheter migration without malfunction early, serial abdominal-pelvic radiographic examinations were performed according to a predefined protocol. Conservative management with rigorous catharsis was undertaken to correct catheter migration. A Kaplan-Meier method was used to calculate survival rate. RESULTS: Mean follow-up period was 42.8 ± 34.9 months. Catheter migration occurred in 62.4%. Among them, 85.9% occurred within the first 2 weeks after catheter insertion. There were no significant associations between catheter migration and variables such as gender, obesity, DM and type of catheter. Success rate of conservative management with rigorous catharsis was 91.1%. Catheter survival at 1 and 5 years were 91.5% and 64.6% in the migration group and 81.2% and 69.9% in the non-migration group, respectively (Log-rank test, P = 0.915). Patient survival at 1 and 5 years were 96.8% and 85.8% in the migration group and 91.9% and 82.3% in the non-migration group, respectively (P = 0.792). CONCLUSION: Early detection of PD catheter migration allowed the migrated tip to be easily corrected with conservative management. Once the migrated catheter tip was restored, catheter migration itself did not affect catheter survival. These findings suggest that early detection and correction of catheter migration is important for improving clinical outcomes.

Surface alterations following instrumentation with a nylon or metal brush evaluated with confocal microscopy.

PURPOSE: Surface alterations of titanium discs following instrumentation with either a nylon brush or a metal brush were evaluated. METHODS: A total of 27 titanium discs with 3 surface types (9 discs for each type), including machined (M) surfaces, sandblasted and acid-etched (SA) surfaces, and surfaces treated by resorbable blast media (RBM), were used. Three discs were instrumented with a nylon brush, another 3 discs were instrumented with a metal brush, and the remaining 3 discs were used as controls for each surface type. Surface properties including the arithmetic mean value of a linear profile (Ra), maximum height of a linear profile (Rz), skewness of the assessed linear profile (Rsk), arithmetic mean height of a surface (Sa), maximum height of a surface (Sz), developed interfacial area ratio (Sdr), skewness of a surface profile (Ssk), and kurtosis of a surface profile (Sku) were measured using confocal microscopy. RESULTS: Instrumentation with the nylon brush increased the Ra, Sa, and Sdr of the M surfaces. On the SA surfaces, Ra, Sa and Sdr decreased after nylon brush use. Meanwhile, the roughness of the RBM surface was not affected by the nylon brush. The use of the metal brush also increased the Ra, Sa, and Sdr of the M surface; however, the increase in Sdr was not statistically significant (P=0.119). The decreases in the Rz, Sz, Ra, Sa, and Sdr of the SA surfaces were remarkable. On the RBM surfaces, the use of the metal brush did not cause changes in Ra and Sa, whereas Rz, Sz, and Sdr were reduced. CONCLUSIONS: Titanium surfaces were altered when instrumented either with a nylon brush or a metal brush. Hence, it is recommended that nylon or metal brushes be used with caution in order to avoid damaging the implant fixture/abutment surface.

Lovastatin increases the proliferation and osteoblastic differentiation of human gingiva-derived stem cells in three-dimensional cultures.

Lovastatin is a cholesterol-lowering agent that also has effects of cell proliferation and apoptosis. The present study was performed to evaluate the effects of lovastatin on the proliferation and osteogenic differentiation of three-dimensional cell spheroids formed from human gingiva-derived stem cells (GDSCs) using concave microwells. GDSCs were plated on polydimethylsiloxane-based concave micromolds and grown in the presence of lovastatin at concentrations of 0, 2 and 6 µM. The morphology of the cells was viewed under an inverted microscope, and cell viability was determined with Cell Counting kit-8 on days 2, 7 and 14. Alkaline phosphatase activity assays were performed to evaluate the osteogenic differentiation on days 2 and 8. Alizarin red-S staining was also used to assess the mineralization of the stem cell spheroids at day 14. The results confirmed that GDSCs formed spheroids in concave microwells. No significant changes were noted with longer incubation time, and no significant differences in cell viability were noted between the three lovastatin groups at each time point. Higher osteogenic differentiation was observed in the 2 µM group when compared with the control. Mineralized extracellular deposits were visible after Alizarin red-S staining, and higher mineralization was noted in the 2 and 6 µM lovastatin groups when compared with the 0 µM control. The relative mineralization values of the 0, 2 and 6 µM groups on day 14 were 39.0±9.6, 69.3±6.0 and 60.9±7.5, respectively. This study demonstrated that the application of lovastatin enhanced the osteogenic differentiation of cell spheroids formed from GDSCs. This suggests that combinations of lovastatin and stem cell spheroids may have the potential for use in tissue engineering.

Analysis of Alveolar Bone Morphology of the Maxillary Central and Lateral Incisors with Normal Occlusion.

Background and objectives: This study investigated the morphology of the labial and palatal bony wall of the maxillary central and lateral incisors using cone-beam computed tomography (CBCT). The difference between males and females and the measurement between right and left sides were measured. Materials and Methods: Twenty participants, consisting of 11 females and 9 males having normal occlusion, were used for the analysis. The mean age was 21.9 ± 3.0 years. The thickness of the labial bony wall and palatal bony wall, perpendicular to the long axis of the root, were evaluated at 3 and 5 mm apical from the cemento-enamel junction (CEJ) and at the root apex. The available bony wall below the apex of the central and lateral incisors, and the angulation between the long axis of the tested tooth and outer surface of the labial bone were measured. Results: The mean labial bony wall thickness at the 3 and 5 mm apical from the CEJ were 1.1 ± 0.3 mm and 1.0 ± 0.4 mm for central incisors, respectively, as well as 1.2 ± 0.4 mm and 1.0 ± 0.4 mm for lateral incisors, respectively. The mean palatal bony wall thickness at 5 mm from the CEJ was above 2 mm in the central and lateral incisors. The percentage of labial bony wall thickness 2 mm or greater at the root apex in central incisors was higher than in lateral incisors (62.5% vs. 55.0%). The percentage of palatal bony wall thickness ≥2 mm at 3 mm apical from the CEJ in the central incisors was higher than in the lateral incisors (37.5% vs. 15.0%). The results on the left and right sides did not show statistically significant differences, except in the labial and palatal bony wall thickness at 3 mm from the CEJ in the lateral incisor. Generally, no significant differences were seen between males and females, but males had a significantly higher labial bony wall thickness at 3 and 5 mm from the CEJ in the central and lateral incisors when compared with females. Conclusions: This study showed that a majority of the cases of Korean participants had less than 2 mm of labial bony wall thickness at 3 and 5 mm apical from the CEJ at central and lateral incisors, and this should be kept in mind while performing dental practices, including tooth extraction or immediate implantation in anterior regions. Preoperative analysis using CBCT may be beneficial for establishing the treatment plan.

Decontamination methods to restore the biocompatibility of contaminated titanium surfaces.

PURPOSE: The reaction of cells to a titanium implant depends on the surface characteristics of the implant which are affected by decontamination. The aim of this study was to evaluate the cytocompatibility of titanium disks treated with various decontamination methods, using salivary bacterial contamination with dental pellicle formation as an in vitro model. METHODS: Sand-blasted and acid-etched (SA) titanium disks were used. Three control groups (pristine SA disks [SA group]; salivary pellicle-coated SA disks [pellicle group]; and biofilm-coated, untreated SA disks [NT group]) were not subjected to any decontamination treatments. Decontamination of the biofilm-coated disks was performed by 14 methods, including ultrasonic instruments, rotating instruments, an air-powder abrasive system, a laser, and chemical agents. MG63 cells were cultured in the presence of the treated disks. Cell proliferation assays were performed on days 2 and 5 of cell culture, and cell morphology was analyzed by immunofluorescence and scanning electron microscopy (SEM). A vascular endothelial growth factor (VEGF) assay was performed on day 5 of culture. RESULTS: The cell proliferation assay revealed that all decontaminated disks, except for the 2 groups treated using a plastic tip, showed significantly less cell proliferation than the SA group. The immunofluorescence and SEM analyses revealed that most groups showed comparable cell density, with the exception of the NT group, in which the cell density was lower and bacterial residue was observed. Furthermore, the cells grown with tetracycline-treated titanium disks showed significantly lower VEGF production than those in the SA group. CONCLUSIONS: None of the decontamination methods resulted in cytocompatibility similar to that of pristine SA titanium. However, many methods caused improvement in the biocompatibility of the titanium disks in comparison with the biofilm-coated, untreated titanium disks. This suggests that decontamination is indispensable for the treatment of peri-implantitis, even if the original biocompatibility cannot be restored.

Evaluation of fibroblast growth factor-2 on the proliferation of osteogenic potential and protein expression of stem cell spheroids composed of stem cells derived from bone marrow.

Fibroblast growth factor-2 (FGF-2) is reported to have various functions and is considered a key human mesenchymal stem cell mitogen, often supplemented to increase human mesenchymal stem cell growth rates. The purpose of this study was to evaluate the effects of FGF-2 on cellular viability and osteogenic differentiation using three-dimensional cell spheroids of stem cells. Three-dimensional cell spheroids were fabricated using concave silicon elastomer-based microwells in the presence of FGF-2 at concentrations of 0, 30, 60 and 90 ng/ml. Qualitative cellular viability was determined with a confocal microscope, and quantitative cellular viability was evaluated using a Cell Counting Kit-8 assay. Alkaline phosphatase activity and Alizarin Red S staining were used to assess osteogenic differentiation. Spheroids were well formed in silicon elastomer-based concave microwells on Day 1. The average spheroid diameters at Day 1 for FGF-2 at 0, 30, 60 and 90 ng/ml were 202.2±3.0, 206.6±22.6, 208.8±6.8 and 196.6±26.7 µm, respectively (P>0.05). The majority of the cells in the cell spheroids emitted green fluorescence. The relative Cell Counting Kit-8 assay values for FGF-2 at 0, 30, 60 and 90 ng/ml at Day 1 were 100.0±5.5, 101.8±8.8, 99.2±4.8 and 103.4±9.6% (P>0.05). The addition of FGF-2 at 60 ng/ml concentration produced the highest value for alkaline phosphatase activity. Mineralized extracellular deposits were evenly observed in each group, and the highest value was identified for FGF-2 groups at 60 ng/ml concentration for Alizarin Red S staining. Based on these findings, it was concluded that FGF-2 may increase alkaline phosphatase activity or Alizarin Red S staining, and further studies are needed to fully elucidate the mechanisms of FGF-2.

The sensitive detection of ODAM by using sandwich-type biosensors with a cognate pair of aptamers for the early diagnosis of periodontal disease.

This research aims to develop biosensors which could diagnose periodontal diseases in early phases and predict the illness stage of patients, in order to give them adequate treatment timely. Human odontogenic ameloblast-associated protein (ODAM) is considered to be a potential biomarker for periodontal diseases, based on high correlation between the level of ODAM in gingival crevicular fluid (GCF) and the degree of periodontitis. Many aptamers, including a cognate pair of aptamers which can bind to the different sites of ODAM, were successfully screened in a very stringent condition employing saliva as a counter target through the graphene oxide-based systemic evolution of ligands by exponential enrichment (GO-SELEX). For the characterization of the aptamer candidates, GO-based fluorescence resonance energy transfer (GO-FRET) and surface plasmon resonance (SPR) assays were conducted. The sandwich-type binding of a cognate pair of aptamers to ODAM was additionally confirmed by employing circular dichroism (CD) and magnetic beads-based fluorescence imaging methods. The resulting cognate pair of aptamers, OD64 and OD35, were found to have their dissociation constant (Kd), 47.71 nM and 51.36 nM, respectively. The minimum detectable concentrations of a sandwich-type SPR biosensor were found to be 0.24 nM and 1.63 nM, respectively, for both buffered and saliva samples. Finally, using this cognate pair of aptamers, a sandwich-type lateral flow strip biosensor was successfully realized. This research shows the potential for implementation of a cognate pair of aptamers on point-of-care biosensors which enables simple, rapid, and non-invasive saliva-based diagnosis of periodontal-related diseases that can overcome current diagnostic methods and improve health care system.