Cellularity and its relation with capsular characteristics as an influencing factor for operative strategies of pleomorphic adenoma.

INTRODUCTION: This study investigates the relationship between cellularity and capsular characteristics of pleomorphic adenoma and its influence on operative strategies. MATERIAL AND METHODS: The capsular characteristics and clinical data of patients with pleomorphic adenomas were reviewed according to Seifert's definition: (1) classic type with balanced amount of cells and stroma, (2) myxoid type with abundant ground substance, interspersed spindle cells, and (3) cellular type with predominance of ductal trabecular structures and little stroma. The immunoreactivity of cellular proliferation (Ki-67) was semi-quantitatively measured using immunohistochemistry. Variables were analyzed using Fisher's test and one-way ANOVA, with (p < 0.05) considered statistically significant. RESULTS: The duration of presence was associated with cellularity (p = 0.01). In terms of capsular characteristics, satellite nodules and positive resection margins were not related to cellularity, except for incomplete capsules (p = 0.03). There was no difference in the staining scores of Ki-67 (p = 0.12). CONCLUSION: Lower cellularity reflects higher probability of an incomplete capsule, requiring more consideration for operative strategies to prevent recurrence.

INTRODUCCIÓN: Este estudio investiga la relación entre la celularidad y las características capsulares del adenoma pleomórfico y su influencia en las estrategias operativas. MATERIAL Y MÉTODOS: Se revisaron las características capsulares y los datos clínicos de los pacientes con adenomas pleomórficos según la definición de Seifert: 1) tipo clásico con cantidad equilibrada de células y estroma, 2) tipo mixoide con abundante sustancia fundamental, células fusiformes intercaladas y 3) tipo celular con predominio de estructuras trabeculares ductales y poco estroma. La inmunorreactividad de la proliferación celular (Ki-67) se midió semicuantitativamente usando inmunohistoquímica. Las variables se analizaron mediante la prueba de Fisher y ANOVA de una vía, considerándose significativo un valor de p inferior a 0.05. RESULTADOS: La duración de la presencia se asoció con la celularidad (p = 0.01). En cuanto a las características capsulares, los nódulos satélites y los márgenes de resección positivos no se relacionaron con la celularidad, a excepción de las cápsulas incompletas (p = 0.03). No hubo diferencia en las puntuaciones de tinción de Ki-67 (p = 0.12). CONCLUSIONES: La celularidad más baja refleja una mayor probabilidad de una cápsula incompleta, lo que requiere una mayor consideración de las estrategias quirúrgicas para prevenir la recurrencia.

A Cross-Sectional Study of Endogenous Antioxidants and Patterns of Dental Visits of Periodontitis Patients.

Periodontitis is an inflammatory disease, wherein endogenous antioxidants help to balance the inflammatory status. Oral health behaviors are related to the periodontal disease status. The aim of this study was to explore the associations between oral health behaviors and endogenous antioxidants in periodontitis patients. In total, 225 subjects diagnosed with periodontitis were enrolled in the study. Information obtained from the initial interview included socioeconomic and demographic characteristics, lifestyle factors, and oral health-related behaviors. The clinical periodontal parameters evaluated included bleeding on probing (BOP), the plaque index (PI), and probing depth (PD). Stimulated saliva was collected before periodontal therapy to determine five endogenous antioxidants (copper-zinc superoxide dismutase (Cu/Zn SOD), manganese SOD (MnSOD), thioredoxin 1 (Trx1), peroxiredoxin 2 (Prx2), and catalase (CAT)). When these five factors were adjusted for in patients whose last previous dental visit was >1 year, the patients' PI, BOP, and PD showed significant decreases because of an elevation in the Cu/Zn SOD level. Associations of endogenous antioxidants with levels of clinical periodontal parameters were much higher in subjects whose last previous dental visit was >1 year, compared to subjects whose last previous dental visit was <1 year. This study provides a better understanding of dental visit patterns and the salivary endogenous antioxidants that may underlie the symptomatic development of preclinical periodontitis.

The association between fecal hemoglobin concentration and oral potentially malignant disorders.

OBJECTIVES: The present study was to investigate the association between fecal hemoglobin (f-Hb) concentration and oral cancer and its precursor, oral potentially malignant disorders (OPMD). METHODS: We used a population-based longitudinal cohort study data based on both Taiwanese nationwide oral and colorectal cancer screening programs implemented between 2004 and 2009. The total of 235,234 smokers and/or betel-quid chewers aged 50 to 69 years free of oral cancer and OPMD at entry were followed up over time to quantify the association between baseline f-Hb concentration on newly diagnosed oral cancer and OPMD. RESULTS: The risk of OPMD increased with baseline f-Hb in a dose manner, yielding a statistically significant elevated risk of developing OPMD in parallel with the incremental concentration of f-Hb (adjusted hazard ratios = 0.99, 1,11, 1,07, 1,57, and 1,63 for f-Hb categories of 1-9, 10-19, 20-49, 50-89, and ≥90 µg Hb/g, respectively, as compared with the reference group (low and undetectable f-Hb concentrations)) However, there was lacking of a statistical significance for the corresponding association regarding the risk of oral cancer, which is possibly due to sparse cases given a shorter follow-up time. CONCLUSION: We discovered that f-Hb concentration was positively related to the risk of OPMD. f-Hb can be used as a biomarker for early detection of OPMD.

Cigarette Smoking Aggravates the Activity of Periodontal Disease by Disrupting Redox Homeostasis- An Observational Study.

The aim of this study was to evaluate the associations between cigarette use and five salivary oxidative stress biomarkers, copper-zinc superoxide dismutase (Cu/Zn SOD), manganese superoxide dismutase (MnSOD), catalase, thioredoxin-1 (TRX1), and peroxiredoxin-2 (PRX2), to assess the effectiveness of non-surgical periodontal therapy. MATERIALS AND METHODS: This is an observational study,167 patients diagnosed with periodontitis were recruited. Both saliva samples and clinical measurements (plaque index (PI), bleeding on probing (BOP), and pocket depth (PD)) were taken at baseline and after completing non-surgical periodontal therapy. The Levels of salivary biomarkers were determined using a MILLIPLEX® MAP Human Oxidative Stress Magnetic Bead Panel kit. The overall reductions in PI and BOP were 31.56% and 42.16%, respectively. BOP reduction after treatment in female or male non-smokers was significantly higher than in male former smokers (p < 0.05). After completing non-surgical periodontal therapy, Cu/ZnSOD, MnSOD, catalase, and Prx2 significantly decreased. There was a significant interaction between smoking status and ΔCu/ZnSOD on PI and a significant interaction between smoking status and ΔCatalase on BOP. CONCLUSIONS: Cigarette smoking interferes with redox homeostasis in the body, alters antioxidants levels, and influences the periodontal disease activity.

Bone regeneration using a porcine bone substitute collagen composite in vitro and in vivo.

The biocharacteristics of xenogeneic grafts make them a possible substitute for autogenous bone grafts in dental bone graft procedures. This study aimed to develop a novel porcine graft with collagen capable of generating new bone in bone defects via osteoconduction over 8 weeks of healing and to compare it with a porcine graft. The porcine collagen graft was made to undergo a cell viability test (MTT) and alkaline phosphatase assay (ALP). The surgical procedure was performed in 20 male adult New Zealand white rabbits. Four calvarial critical-size defects of 6 mm in diameter were prepared in each rabbit. The upper left defect was filled with a porcine graft of 500-1000 µm, the upper right with a porcine collagen graft, the lower left with hydroxyapatite/beta-tricalcium phosphate and the lower right served as the control without any filling material. The rabbits were divided and sacrificed at 2, 4, 6 and 8 weeks after surgery. Histological and micro-CT scan results showed that the performance of the porcine collagen graft is superior for regenerating new bone. Porcine collagen graft showed cell viability and osteoblast-like cell differentiation in vitro. The results indicate that porcine collagen graft is a potential bone substitute for clinical application.

Static magnetic fields enhance dental pulp stem cell proliferation by activating the p38 mitogen-activated protein kinase pathway as its putative mechanism.

Dental pulp stem cells (DPSCs) can be a potential stem cell resource for clinical cell therapy and tissue engineering. However, obtaining a sufficient number of DPSCs for repairing defects is still an issue in clinical applications. Static magnetic fields (SMFs) enhance the proliferation of several cell types. Whether or not SMFs have a positive effect on DPSC proliferation is unknown. Therefore, the aim of this study was to investigate the effect of SMFs on DPSC proliferation and its possible intracellular mechanism of action. For methodology, isolated DPSCs were cultured with a 0.4-T SMF. Anisotropy of the lipid bilayer was examined using a fluorescence polarization-depolarization assay. The intracellular calcium ions of the SMF-treated cells were analysed using Fura-2 acetoxymethyl ester labelling. The cytoskeletons of exposed and unexposed control cells were labelled with actin fluorescence dyes. Cell viability was checked when the tested cells were cultured with inhibitors of ERK, JNK and p38 to discern the possible signalling cascade involved in the proliferative effect of the SMF on the DPSCs. Our results showed that SMF-treated cells demonstrated a higher proliferation rate and anisotropy value. The intracellular calcium ions were activated by SMFs. In addition, fluorescence microscopy images demonstrated that SMF-treated cells exhibit higher fluorescence intensity of the actin cytoskeletal structure. Cell viability and real-time polymerase chain reaction suggested that the p38 signalling cascade was activated when the DPSCs were exposed to a 0.4-T SMF. F-actin intensity tests showed that SB203580-treated cells decreased even with SMF exposure. Additionally, the F-/G-actin ratio increased due to slowing of the cytoskeleton reorganization by p38 mitogen-activated protein kinase inhibition. According to these results, we suggest that a 0.4-T SMF affected the cellular membranes of the DPSCs and activated intracellular calcium ions. This effect may activate p38 mitogen-activated protein kinase signalling, and thus reorganize the cytoskeleton, which contributes to the increased cell proliferation of the DPSCs. Copyright © 2016 John Wiley & Sons, Ltd.

Prophylactic supplement with melatonin successfully suppresses the pathogenesis of periodontitis through normalizing RANKL/OPG ratio and depressing the TLR4/MyD88 signaling pathway.

Periodontitis (PD) is an inflammatory disease characterized by gingival inflammation and resorption of alveolar bone. Impaired receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling caused by enhanced production of pro-inflammatory cytokines plays an essential role in the pathogenesis of PD. Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD. PD was induced in adult rats by placing the ligature at molar subgingival regions. Fourteen days before PD induction, 10, 50, or 100 mg/kg of melatonin was intraperitoneally injected for consecutive 28 days. Biochemical and enzyme-linked immunosorbent assay were used to detect TLR4/MyD88 activity, RANKL, OPG, interleukin 1ß, interleukin 6, and tumor necrosis factor-α levels, respectively. The extent of bone loss, bone mineral intensity, and calcium intensity was further evaluated by scanning electron microscopy, micro-computed tomography, and energy-dispersive X-ray spectroscopy. Results indicated that high RANKL/OPG ratio, TLR4/MyD88 activity, and pro-inflammatory cytokine levels were detected following PD. Impaired biochemical findings paralleled well with severe bone loss and reduced calcium intensity. However, in rats pretreated with melatonin, all above parameters were successfully returned to nearly normal levels with maximal change observed in rats receiving 100 mg/kg. As prophylactic treatment with melatonin effectively normalizes RANKL/OPG signaling by depressing TLR4/MyD88-mediated pro-inflammatory cytokine production, dietary supplement with melatonin may serve as an advanced strategy to strengthen oral health to counteract PD-induced destructive damage.

An evaluation of the biocompatibility and osseointegration of novel glass fiber reinforced composite implants: In vitro and in vivo studies.

OBJECTIVES: The aim of this study was to evaluate the in vitro biocompatibility and in vivo osseointegration of three novel bioactive glass fiber reinforced composite (GFRC) implants and to compare these with metal (Ti6Al4V) implants. METHODS: The surfaces of these experimental substrates were characterized by scanning electron microscopy (SEM), a 2D profilometer and by contact angle measurement. In vitro biological performance was assessed using MG-63 human osteoblast-like cell morphology, cell proliferation assays and the alkaline phosphatase (ALP) activity testing. Furthermore, in vivo osseointegration performance was examined by installing samples into rabbit femurs and evaluated the results using micro-CT, histology and histomorphometrical analysis; these assessments were carried out after 1, 2, 4 and 8 weeks of healing. RESULTS: The results showed that moderate surface roughness, moderate hydrophilic exposure and moderate homogenous exposure of bioactive glass fibers were present for all of the GFRC substrates. Furthermore, MG-63 cells, when cultured on all of the GFRC substrates, grew well and exhibited a more differentiated phenotype than cells grown on titanium alloy (Ti6Al4V) substrate. Histological evaluation revealed more newly-formed bone regeneration within the thread of the GFRC implants during the initial healing period. In addition, the novel GFRC implants with a bioactive Bio-fiber structure and glass particles within the epoxy resin matrix showed better bone volume/tissue volume (BV/TV) values at 4 weeks and this was accompanied by bone-implant contact (BIC) values at 8 weeks comparable to the Ti6Al4V group. SIGNIFICANCE: These findings demonstrated that novel GFRC implants seem to show improved osteogenesis and osseointegration functionality and have potential as a substitute for Ti6Al4V, or other metal-based materials, when used for clinically dental and orthopedic applications.

Fluconazole induces rapid high-frequency MTL homozygosis with microbiological polymorphism in Candida albicans.

BACKGROUND: Candida albicans, a common fungal pathogen that can cause opportunistic infections, is regarded as an apparently asexual, diploid fungus. A parasexual cycle was previously found between homozygotes with opposite mating type-like loci (MTLa/α). Fluconazole-resistant strains had a higher proportion of MTL homozygotes, whereas MTL homozygous C. albicans was found in only about 3.2% of clinical strains. MTL heterozygotes had a low frequency (1.4 × 10-4) of white-opaque switching to MTL homozygotes in nature. METHODS: Here, a reference C. albicans strain (SC5314) was used in a fluconazole-induced assay to obtain standard opaque MTL homozygous strains and first-generation daughter strains from the fluconazole inhibition zone. Further separation methods were employed to produce second- and third-generation daughter strains. Polymerase chain reaction analysis based on MTL genes was used to define MTL genotypes, and microscopic observations, a flow-cytometric assay, and an antifungal E-test were used to compare microbiological characteristics. RESULTS: MTL homozygotes were found at a high frequency (17 of 35; 48.6%) in fluconazole-induced first-generation daughter strains, as were morphological polymorphisms, decreased DNA content, and modified antifungal drug susceptibility. High-frequency MTL homozygosity was identified inside the fluconazole inhibition zone within 24 hours. The DNA content of fluconazole-induced daughter strains was reduced compared with their progenitor SC5314 and standard MTL homozygous strains. CONCLUSION: Treatment with fluconazole, commonly used to treat invasive candidiasis, inhibited the growth of C. albicans and altered its microbiological characteristics. Our results suggest that fluconazole treatment induces the high frequency of loss of heterozygosity and microbiological polymorphism in C. albicans.

Oxygen-implanted induced formation of oxide layer enhances blood compatibility on titanium for biomedical applications.

Titanium dioxide (TiO2) layers were prepared on a Ti substrate by using oxygen plasma immersion ion implantation (oxygen PIII). The surface chemical states, structure, and morphology of the layers were studied using X-ray photoelectron spectroscopy, X-ray diffraction, Raman microscopy, atomic force microscopy and scanning electron microscope. The mechanical properties, such as the Young's modulus and hardness, of the layers were investigated using nanoindentation testing. The Ti(4+) chemical state was determined to be present on oxygen-PIII-treated surfaces, which consisted of nanocrystalline TiO2 with a rutile structure. Compared with Ti substrates, the oxygen-PIII-treated surfaces exhibited decreased Young's moduli and hardness. Parameters indicating the blood compatibility of the oxygen-PIII-treated surfaces, including the clotting time and platelet adhesion and activation, were studied in vitro. Clotting time assays indicated that the clotting time of oxygen-PIII-treated surfaces was longer than that of the Ti substrate, which was associated with decreased fibrinogen adsorption. In conclusion, the surface characteristics and the blood compatibility of Ti implants can be modified and improved using oxygen PIII.

Fibronectin-Grafted Titanium Dental Implants: An In Vivo Study.

Modification of the physiochemical properties of titanium surfaces using glow discharge plasma (GDP) and fibronectin coating has been shown to enhance the surface hydrophilicity, surface roughness, cell adhesion, migration, and proliferation. This in vivo study aimed to evaluate the bone integration efficacy of a biologically modified implant surface. Two different surface-modified implants (Ar-GDP and GDP-fib) were placed in the mandibular premolar area of six beagle dogs for 2-8 weeks. Three techniques [histologic evaluation, resonance frequency analysis (RFA), and microcomputed tomography (micro-CT) evaluation] were used to detect the implant stability and bone-implant contact. The implant stability quotient values of GDP-fib implants were significantly greater than the Ar-GDP implants at 2 and 4 weeks (P < 0.01). The bone volume/total volume ratio of GDP-fib implants was greater than the Ar-GDP implants in micro-CT evaluation. A high positive correlation was observed between RFA and micro-CT measurements. At 2 weeks, osteoblasts were seen to line the implant surface, and multinuclear osteoclasts could be seen on the surface of old parent bone. After 8 weeks, a majority of the space in the wound chamber appeared to be replaced by bone. Enhancement of the stability of biologically modified implants was proved by the results of RFA, micro-CT, and histological analysis. This enhanced stability may help fasten treatment and be clinically beneficial.

Effects of Salivary Oxidative Markers on Edentulous Patients' Satisfaction with Prosthetic Denture Treatments: A Pilot Study.

OBJECTIVES: The purpose of this study was to assess relationships among periodontal conditions, salivary antioxidant levels, and patients' satisfaction with their prostheses. METHODS: This study was conducted at the Division of Prosthodontics, Department of Dentistry, Taipei Medical University Hospital. The periodontal condition of patients was based on an assessment of the plaque index (PI) and gingival index (GI). The pH value, flow rate, and buffer capacity of the saliva were estimated. The salivary total antioxidant status (TAS) and superoxide dismutase (SOD) level were also determined. Patients' satisfaction with prosthetic treatments was evaluated using the Chinese version of the short-form Oral Health Impact Profile (OHIP-14C). A multivariate regression model was used to determine whether patients' satisfaction with prosthetic treatment was affected by their oral health status. RESULTS: In total, 35 edentulous patients were recruited. In the Spearman correlation analysis, salivary pH (r = -0.36, p = 0.03) and the buffer ability (r = -0.48, p<0.01) were associated with OHIP-14C scores. In the multivariate analysis, patients who had a higher GI also had a higher score of physical disabilities (ß = 1.38, p = 0.04). Levels of SOD increased with the scores of psychological discomfort (ß = 0.33 U/g protein, p = 0.04). CONCLUSIONS: This study suggested that both the GI and SOD levels were associated with patients' satisfaction with prosthetic treatments. To the best of our knowledge, this is the first study to elucidate the relationship between OHIP scores and salivary oxidative markers in edentulous patients.

In Vitro Analysis of Fibronectin-Modified Titanium Surfaces.

BACKGROUND: Glow discharge plasma (GDP) procedure is an effective method for grafting various proteins, including albumin, type I collagen, and fibronectin, onto a titanium surface. However, the behavior and impact of titanium (Ti) surface modification is yet to be unraveled. PURPOSE: The purpose of this study is to evaluate and analyze the biological properties of fibronectin-grafted Ti surfaces treated by GDP. MATERIALS AND METHODS: Grade II Ti discs were initially cleaned and autoclaved to obtain original specimens. Subsequently, the specimens were GDP treated and grafted with fibronectin to form Ar-GDP (Argon GDP treatment only) and GDP-fib (fibronectin coating following GDP treatment) groups. Blood coagulation test and MG-63 cell culture were performed to evaluate the biological effects on the specimen. RESULTS: There was no significant difference between Ar-GDP and GDP-fib groups in blood compatibility analysis. While in the MTT test, cellular proliferation was benefited from the presence of fibronectin coating. The numbers of cells on Ar-GDP and GDP-fib specimens were greater than those in the original specimens after 24 h of culturing. CONCLUSIONS: GDP treatment combined with fibronectin grafting favored MG-63 cell adhesion, migration, and proliferation on titanium surfaces, which could be attributed to the improved surface properties.

Bone Healing Improvements Using Hyaluronic Acid and Hydroxyapatite/Beta-Tricalcium Phosphate in Combination: An Animal Study.

The purpose of this study was to investigate whether the use of HLA as an aqueous binder of hydroxyapatite/beta-tricalcium phosphate (HA-ßTCP) particles can reduce the amount of bone graft needed and increase ease of handling in clinical situations. In this study, HA/ßTCP was loaded in commercially available crosslinking HLA to form a novel HLA/HA-ßTCP composite. Six New Zealand White rabbits (3.0-3.6 kg) were used as test subjects. Four 6 mm defects were prepared in the parietal bone. The defects were filled with the HLA/HA-ßTCP composite as well as HA-ßTCP particle alone. New bone formation was analyzed by micro-CT and histomorphometry. Our results indicated that even when the HA-ßTCP particle numbers were reduced, the regenerative effect on bone remained when the HLA existed. The bone volume density (BV/TV ratio) of HLA/HA-ßTCP samples was 1.7 times larger than that of the control sample at week 2. The new bone increasing ratio (NBIR) of HLA/HA-ßTCP samples was 1.78 times higher than the control group at week 2. In conclusion, HA-ßTCP powder with HLA contributed to bone healing in rabbit calvarial bone defects. The addition of HLA to bone grafts not only promoted osteoconduction but also improved handling characteristics in clinical situations.

A Novel HA/ß-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs.

Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable purified fibrillar collagen and hydroxyapatite/ß-tricalcium phosphate (HA/ß-TCP) ceramic composite versus collagen alone and a bovine xenograft-collagen composite in beagles. Collagen plugs, bovine graft-collagen composite and HA/ß-TCP-collagen composite were implanted into the left and right first, second and third mandibular premolars, and the fourth molar was left empty for natural healing. In total, 20 male beagle dogs were used, and quantitative and histological analyses of the extraction ridge was done. The smallest width reduction was 19.09% ± 8.81% with the HA/ß-TCP-collagen composite at Week 8, accompanied by new bone formation at Weeks 4 and 8. The HA/ß-TCP-collagen composite performed well, as a new osteoconductive and biomimetic composite biomaterial, for socket bone preservation after tooth extraction.

In Vitro and In Vivo Study of a Novel Porcine Collagen Membrane for Guided Bone Regeneration.

For years, in order to improve bone regeneration and prevent the need of a second stage surgery to remove non-resorbable membranes, biological absorbable membranes have gradually been developed and applied in guided tissue regeneration (GTR). The present study's main objective was to achieve space maintenance and bone regeneration using a new freeze-dried developed porcine collagen membrane, and compare it with an already commercial collagen membrane, when both were used with a bovine xenograft in prepared alveolar ridge bone defects. Prior to surgery, the membrane's vitality analysis showed statistically significant higher cell proliferation in the test membrane over the commercial one. In six beagle dogs, commercial bone xenograft was packed in lateral ridge bone defects prepared in the left and right side and then covered with test porcine collagen membrane or commercial collagen membrane. Alveolar height changes were measured. Histomorphometric results, in vitro and in vivo properties indicated that the new porcine collagen membrane is biocompatible, enhances bone xenograft osteoconduction, and reduces the alveolar ridge height reabsorption rate.

Modal damping factor detected with an impulse-forced vibration method provides additional information on osseointegration during dental implant healing.

PURPOSE: To evaluate whether resonance frequency (RF) analysis combined with modal damping factor (MDF) analysis provides additional information on dental implant healing status. MATERIALS AND METHODS: In in vitro tests, epoxy resin was used to simulate the implant healing process. The RF and MDF values of the implants were measured during the entire polymerization process. Implant stability quotient (ISQ) and Periotest values (PTVs) from Ostell and Periotest devices were used to validate the apparatus. In in vivo experiments, vibrational analysis was performed on 17 dental implants in 12 patients. The RF and MDF values of the tested implants were recorded during the first 10 weeks after surgery. The effects of jaw types and primary stability on MDF healing curves were analyzed. RESULTS: In the in vitro model, the RF values obtained from the apparatus used in this study were similar to those obtained from the Osstell device. Unlike the Periotest healing curve, the MDF curve showed a 1.8-fold increase during the early phase. In clinical experiments, the mean RF values were unchanged during the first 2 weeks and increased continuously until 6 weeks. The corresponding mean MDF value decreased over time and reached 0.045 ± 0.011 at 10 weeks, which is approximately 50% lower than the initial value. Although the RF values of the implants with higher initial frequency remained unchanged during the healing period, the MDF values decreased significantly. CONCLUSION: Analysis of RF combined with MDF provides additional information on dental implant healing status. MDF analysis can detect changes in the implant/bone complex during the healing period even in implants with higher RF values.

Change of scaling-induced proinflammatory cytokine on the clinical efficacy of periodontitis treatment.

Proinflammatory cytokines are key inflammatory mediators in periodontitis. This study aimed to investigate the relationship between proinflammatory cytokines in saliva and periodontal status. To investigate the usefulness of cytokines in the therapeutic approach for periodontal disease, the relationship between stimulated cytokine changes and the periodontitis treatment outcome was investigated in this study. Saliva was obtained from 22 patients diagnosed by dentists as having chronic periodontitis. The proinflammatory cytokine (interleukin-1α (IL-1α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), and tumor necrosis factor ß (TNF-ß)) levels were determined using a commercially available kit. The IL-1ß and IL-6 levels increased, whereas the TNF-ß levels decreased with the severity of periodontitis (4 mm pocket percentage). Poststimulation IL-1α, IL-6, and IL-8 levels were higher in patients who had an improved treatment outcome. The differences of IL-6 levels (cut point: 0.05 µg/g) yielded a sensitivity and specificity of 90.0% and 81.82%, respectively, for predicting the periodontitis treatment outcome. Among the proinflammatory cytokines, stimulated IL-6 was an excellent marker for predicting the periodontitis treatment outcome.

Static magnetic field attenuates lipopolysaccharide-induced inflammation in pulp cells by affecting cell membrane stability.

One of the causes of dental pulpitis is lipopolysaccharide- (LPS-) induced inflammatory response. Following pulp tissue inflammation, odontoblasts, dental pulp cells (DPCs), and dental pulp stem cells (DPSCs) will activate and repair damaged tissue to maintain homeostasis. However, when LPS infection is too serious, dental repair is impossible and disease may progress to irreversible pulpitis. Therefore, the aim of this study was to examine whether static magnetic field (SMF) can attenuate inflammatory response of dental pulp cells challenged with LPS. In methodology, dental pulp cells were isolated from extracted teeth. The population of DPSCs in the cultured DPCs was identified by phenotypes and multilineage differentiation. The effects of 0.4 T SMF on DPCs were observed through MTT assay and fluorescent anisotropy assay. Our results showed that the SMF exposure had no effect on surface markers or multilineage differentiation capability. However, SMF exposure increases cell viability by 15%. In addition, SMF increased cell membrane rigidity which is directly related to higher fluorescent anisotropy. In the LPS-challenged condition, DPCs treated with SMF demonstrated a higher tolerance to LPS-induced inflammatory response when compared to untreated controls. According to these results, we suggest that 0.4 T SMF attenuates LPS-induced inflammatory response to DPCs by changing cell membrane stability.

Static magnetic field attenuates lipopolysaccharide-induced multiple organ failure: a histopathologic study in mice.

PURPOSE: Previous studies demonstrated that static magnetic fields (SMF) were effective in down-regulating the expression of lipopolysaccharide (LPS)-induced inflammatory cytokines. The aim of this study was to provide histological evidence of SMF attenuating LPS-induced multiple organ failure (MOF). MATERIALS AND METHODS: In this study, BALB/cByJNarl (5 weeks, weighing 20-25 g) mice were chosen as test subjects. The tested animals were challenged with 50 mg/kg LPS after they were exposed to a continuous SMF for 2 h. The survival rate and pathological changes in lungs, kidneys, and livers of the LPS- challenged mice were examined with and without SMF treatment. In addition, the effects of SMF exposure on body temperature control of the LPS-challenged mice were monitored. RESULTS: Our results showed that at 30 h the survival rate of LPS-challenged mice increased 3.6-fold (p < 0.05). In addition, 6 h after LPS injection, the average body temperature of SMF-exposed mice was 1.07°C lower than that of unexposed animals. Tissue biopsies demonstrated that SMF exposure reduced damage to the lungs, livers, and kidneys in the LPS-challenged mice. CONCLUSIONS: SMF show potential as a viable prophylactic alternative for controlling LPS-induced MOF.