BACKGROUNDCurrently, several systems of dentin substrate-reacting adhesives are available for use in the restorative treatment against caries. However, the bond effectiveness and property of different adhesive systems to caries-affected dentin are not fully understood. The objective of this study was to evaluate the bond strength of different adhesives to both normal dentin (ND) and caries-affected dentin (CAD) and to analyze the dentin/adhesive interfacial characteristics.

METHODSTwenty eight extracted human molars with coronal medium carious lesions were randomly assigned to four groups according to adhesives used. ND and CAD were bonded with etch-and-rinse adhesive Adper Single Bond 2 (SB2) or self-etching adhesives Clearfil SE Bond (CSE), Clearfil S(3) Bond (CS3), iBond GI (IB). Rectangular sticks of resin-dentin bonded interfaces 0.9 mm(2) were obtained. The specimens were subjected to microtensile bond strength (microTBS) testing at a crosshead speed of 1 mm/min. Mean microTBS was statistically analyzed with analysis of variance (ANOVA) and Student-Newman-Keuls tests. Interfacial morphologies were analyzed by Scanning Electron Microscopy (SEM).

RESULTSEtch-and-rinse adhesive Adper(TM) Single Bond 2 yielded high bond strength when applied to both normal and caries-affected dentin. The two-step self-etching adhesive Clearfil SE Bond generated the highest bond strength to ND among all adhesives tested but a significantly reduced strength when applied to CAD. For the one-step self-etching adhesives, Clearfil S(3) Bond and iBond GI, the bond strength was relatively low regardless of the dentin type. SEM interfacial analysis revealed that hybrid layers were thicker with poorer resin tag formation and less resin-filled lateral branches in the CAD than in the ND for all the adhesives tested.

CONCLUSIONThe etch-and-rinse adhesive performed more effectively to caries-affected dentin than the self-etching adhesives.

Adhesives ; Dental Bonding ; methods ; Dentin ; Humans ; Microscopy, Electron, Scanning ; Molar ; Tensile Strength

OBJECTIVETo investigate clinical feasibility and technical features of immediate loading with linear occlusion on 2-implant-supported overdenture and to evaluate short-term effect of the treatment

METHODSSix edentulous patients with severe residual ridge resorption were enrolled. Two interforaminal implants were inserted for each patient and then immediate impressions were taken. Implant-supported bar-retained overdentures were restored for the patients within 24 hours. Clinical and radiographic examinations were conducted post-operative 1 week and 1, 3, 6, and 12 months. Thereafter at every 6 months the stability of implants, tissue situations around implants, radiographs and satisfaction level of patients were examined for each patient.

RESULTSSix cases and 12 implants were followed from 9 to 30 months. No implant was loosened or dropped. Sulculus bleeding index was 0-1 and probing depth of sulcus was less than 2 mm. The gingival tissues around the implants were healthy. Radiographic examination showed that bone resorption was less than 1 mm in the first year. The alveolar bone around the implants hasn't show obvious resorption stable height. Patients were satisfied with the implants.

CONCLUSIONSThe results of this study indicate that immediate loading using linear occlusion on implant-supported bar-retained overdenture is predictable in some cases and can achieve satisfaction in the short-term service. Further study is needed to assess the long-term results.

Aged ; Dental Implantation, Endosseous ; Dental Implants ; Dental Prosthesis, Implant-Supported ; Denture Retention ; Denture, Complete, Immediate ; Denture, Overlay ; Female ; Follow-Up Studies ; Humans ; Jaw, Edentulous ; surgery ; Male ; Mandible ; surgery ; Middle Aged

This study was aimed to investigate the activation of P38MAPK/STAT3 and expression of telomerase reverse transcriptase during sodium nitroprusside (SNP) inducing apoptosis of human leukemia cell line K562 and to explore the molecular mechanisms of SNP-inducing apoptosis in K562 cells. The K562 cell were treated with different concentrations of SNP and were cultured for different time. Cell apoptosis was analysed by cell morphology, DNA agarose gel electrophoresis, DNA content, and Annexin-V/PI labeling method. The TdT-mediated dUTP nick end labeling (TUNEL) assay was used to quantitate the in situ cell apoptosis. The expressions of phosphorylated p38MAPK or STAT3 were analysed by flow cytometry, while the expression of hTERT mRNA in transcriptional level was measured by fluorescence quantitative RT-PCR. The results showed that SNP inhibited K562 cell growth. The K562 cell apoptosis was confirmed by typical cell morphology and DNA fragment, peak of sub-G1 phase, TUNEL and Annexin-V/PI labeling. A majority of K562 cells were arrested in G0/G1 phase. After treatment with SNP at 0.5-3.0 mmol/L, the expression of phosphorylated-P38MAPK and phosphorylated-STAT3 increased first and decreased afterwards. Incubation of K562 cell with SNP (2 mmol/L) could increase the expression of phosphorylated-P38MAPK and phosphorylated-STAT3 at 12 hours and 24 hours respectively, and down-regulated at 72 hours and 48 hours. SNP could decrease the expression of hTERT-mRNA in time-and dose-dependent manner. It is concluded that SNP can significantly induce K562 cells apoptosis, its mechanism may be related to the activation of P38MAPK and suppression of phosphorylated-STAT3 and hTRET-mRNA.
Apoptosis ; drug effects ; Humans ; K562 Cells ; Nitroprusside ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; STAT3 Transcription Factor ; genetics ; metabolism ; Telomerase ; biosynthesis ; genetics ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

To study the molecular mechanisms of nitric oxide donor sodium nitroprusside (SNP) -induced apoptosis in K562 human leukemia cell line, the different concentrations of SNP and different time of culture were used to treat K562 cell. At the same time, potassium ferricyamide (PFC) was used as control, blank was designed in experiment. Cell apoptosis was analysed by cell morphology, DNA agarose gel electrophoresis, DNA content, and annexin-V/PI labeling method. The TdT-mediated dUTP nick end labeling (TUNEL) assay was used to quantify in situ cell apoptosis. Reactive oxygen species (ROS) in cells and mitochondrial transmembrane potential (DeltaPsim) were labeled by dihydrorhodamin 123, 2', 7'-dichlorodihydrofluorescein diacetate and rhodamin 123/PI. bcl-2, bax, bad, p53 gene proteins and mitochondrial membrane protein were analysed by flow cytometry. The results showed that the K562 cell apoptosis was confirmed by typical cell morphology, DNA fragment, sub-G(1) phase, TUNEL and annexin-V/PI labeling. A majority of K562 cells were arrested in G(0)/G(1) phase. During the process of SNP-induced apoptosis in K562 cell, the mean fluorescence intensity of ROS in cells was significantly higher than those in blank and PFC control, while the DeltaPsim reduced. The expression of p53, bax, bad, Fas protein and mitochondrial membrane protein increased and bcl-2 protein decreased after SNP treatment. It is concluded that SNP induces K562 cell apoptosis through increasing ROS in cells, expressing the p53, bax, bad, Fas protein and mitochondrial membrane protein and decreasing bcl-2 protein, opening the mitochondrial permeability transition pore and reducing DeltaPsim. Furthermore, the Fas was activated during the apoptosis process.
Apoptosis ; drug effects ; Dose-Response Relationship, Drug ; Humans ; In Situ Nick-End Labeling ; K562 Cells ; Membrane Potential, Mitochondrial ; drug effects ; Nitric Oxide Donors ; pharmacology ; Nitroprusside ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Reactive Oxygen Species ; metabolism ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; biosynthesis

BACKGROUNDThe rocking and instability of a loaded complete denture (CD) during lateral excursion reduce the bearing area under the denture base, causing localized high stress concentrations. This can lead to mucosal tenderness, ulceration, and alveolar bone resorption, and the linear occlusion design was to decrease the lateral force exerted on the denture and to ensure denture stability. But it is not known how the bearing areas of linear occlusal CDs (LOCDs) and anatomic occlusal CDs (AOCDs) differ. The purpose of this study was to analyze and compare the distributions of the high and low vertical stress-bearing areas in the mandibular alveolar mucosa under LOCDs and AOCDs at lateral excursion.

METHODSComputerized tomography (CT) and finite element analysis were used to establish three-dimensional models of an edentulous maxilla and mandible with severe residual ridge resorption. These models were composed of maxillary and mandibular bone structure, mucosa, and the LOCD or AOCD. Lateral excursion movements of the mandible were simulated and the vertical stress-bearing areas in the mucosa under both mandibular CDs were analyzed using ANSYS 7.0.

RESULTSOn the working side, the high stress-bearing (-0.07 to -0.1 MPa) area under the LOCD during lateral excursion was smaller than that under the AOCD, while the medium stress-bearing (-0.03 to -0.07 MPa) area under the LOCD was 1.33-fold that under the AOCD. The medium stress-bearing area on the non-working side under the LOCD was 2.4-fold that under the AOCD. Therefore, the overall medium vertical stress-bearing area under the LOCD was 20% larger than that under the AOCD.

CONCLUSIONSDuring lateral excursion, the medium vertical stress-bearing area under a mandibular LOCD was larger and the high vertical stress-bearing area was smaller than that under an AOCD. Thus, the vertical stress under the LOCD was distributed more evenly and over a wider area than that under the AOCD, thereby improving denture stability.

Aged ; Computer Simulation ; Dental Occlusion ; Dental Stress Analysis ; Denture, Complete ; Female ; Finite Element Analysis ; Humans ; Mandible ; physiology ; Stress, Mechanical

BACKGROUNDOcclusal splints have been the preferred modalities in the management of myofascial temporomandibular disorders (TMDs), but now controversy exists in reporting whether they are successful for TMDs treatments. The aim of this study was to give objective evidence to the assessment of treatment effect of occlusal splints for myofascial TMDs patients by clinical assessments and surface electromyography (sEMG) measurements of masseter muscles (MM).

METHODSThirty-six patients (12 males and 24 females) aged 16 - 57 (38 ± 11) years participated in the study. All participants diagnosed with myofascial TMD were randomized into two groups (18 of each). Patients in the first group (A) were treated with occlusal splints for 1 month, while patients in the second group (B) were treated with placebo (non-occluding palatal) splints. Clinical assessments were performed at the beginning of the study and 1 month after treatment. sEMG measurements for MM were performed at mandibular postural position (MPP) and maximum intercuspal contacted position (ICP) 1 month after the treatment. The root mean square (RMS) and the median frequency (MF) as linear indices of sEMG data were used to demonstrate muscle activity and muscle fatigue. Data were analyzed by ANOVA and post hoc SNK test. The differences were considered significant at P < 0.05.

RESULTSIt was found that 89% of group A either completely recovered (39%) or clinically improved (50%), while only 22% of group B had a spontaneous improvement. sEMG analysis showed that at MPP, the mean of RMS value of MM in group A was lower than that of group B, which shows statistical differences (P < 0.01). At ICP, the RMS value of MM in group A was higher than that of group B, which shows statistical differences (P < 0.01). At MPP, MF value of MM in group A was higher than that of group B (P < 0.05). At ICP, MF value of MM was lower than that of group B (P < 0.01).

CONCLUSIONSOcclusal splint could eliminate or improve the signs and symptoms of TMD patients with myofascial pain. sEMG analysis indicates that the wearing of occlusal splints may reduce the degree of fatigue of the masticatory muscles. The splint therapy outcome has a correlation with the electromyographic changes in the masticatory muscles.

Adolescent ; Adult ; Double-Blind Method ; Electromyography ; Female ; Humans ; Male ; Middle Aged ; Myofascial Pain Syndromes ; physiopathology ; therapy ; Splints

OBJECTIVETo investigate the influence of lipopolysaccharide (LPS) on macrophages expressing TNF-alpha related apoptosis induced-ligand (TRAIL) and its relation to apoptosis of HepG2 cell line.

METHODSMembrane-bound TRAIL (mTRAIL) was measured by flow cytometry; soluble TRAIL in supernatant was detected by enzyme-linked immunoabsorbent sandwich assay (ELISA); cytotoxicity of TRAIL to HepG2 cell line was measured by chromium release assay, and apoptosis of HepG2 cell was confirmed by Annexin V staining.

RESULTSLPS only slightly increased membrane-bound TRAIL expression of macrophages. On the other hand, soluble TRAIL in the supernatant was increased with LPS stimulation, and the optimal concentration of LPS was 100 ng/ml (sTRAIL value 67.40 ng/ml+/-5.08 ng/ml). The soluble TRAIL in the supernatant was cytotoxic to HepG2 cells, and this activity can be blocked by TRAIL neutralizing antibodies.

CONCLUSIONLPS increases the expression of soluble TRAIL in macrophages, and soluble TRAIL is toxic to HepG2 cells. All of our results indicate that TRAIL may play an important role in the pathogenesis of viral hepatitis.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Enzyme-Linked Immunosorbent Assay ; Humans ; Lipopolysaccharides ; pharmacology ; Liver Neoplasms ; pathology ; Macrophages ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; biosynthesis ; genetics ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo analyze stress distribution in alveolar bone around implants of implant supported overdentures (ISO) with linear occlusion and with anatomic occlusion at lateral mandibular position, and to justify the possibility of decreased injurious force around implants in ISO with linear occlusion.

METHODSComputerized tomography scan and finite element analysis (FEA) were used to set up two 3-D FEA models of maxillae and mandible with severe residual ridge resorption. The mucosa, linear and anatomic occlusal ISO with bar attachments, and two implants inserted between mandibular foramina were also established in the models. With the condition of imitating the loading of masseter muscles, these models were loaded to simulate the stress distributions in alveolar bone around implants under ISO at lateral occlusion position.

RESULTSAt lateral occlusion, the stress distributions in alveolar bone around implants under ISO with anatomic occlusion were mainly on the lingual and distal sides of the working side implants. However, stress distributions under ISO with linear occlusion were on the distal sides of bilateral implants. Both the stress peaks of ISOs with linear occlusion and with the anatomic one appeared in the working side. In anatomic occlusion model, sigma(z): -6.47 MPa and 6.81 MPa, sigma(1): -4.20 MPa and 7.20 MPa (negative value: compressive stress, positive value: tensile stress); in linear occlusion model, sigma(z): -4.86 MPa and 3.04 MPa, sigma(1): -3.48 MPa and 5.33 MPa.

CONCLUSIONSAt lateral occlusion, when comparing the ISO with two different occlusion schemes, stress peak in alveolar bone around implants in the linear occlusion model was lower than that in the anatomic occlusion model at equal loading situation. Stress in the alveolar bone under ISO with linear occlusion distributed more evenly than that under ISO with anatomic occlusion.

Dental Implantation ; Dental Occlusion ; Denture, Complete, Lower ; Finite Element Analysis ; Humans ; Mandible ; physiology ; Models, Anatomic ; Models, Biological ; Stress, Mechanical

OBJECTIVETo investigate the clinicopathological significance of chromosome 17 polysomy in breast cancer.

METHODSRetrospective study of 200 cases of breast cancer including 106 cases of invasive ductal carcinoma and 94 cases of in-situ carcinoma was performed by fluorescence in-situ hybridization (FISH) to explore the relationship between chromosome 17 polysomy and age, nuclear atypia, lymphatic metastasis, HER2 gene amplification and HER2 protein expression.

RESULTSTwenty-six percent (52/200) of chromosome 17 polysomy was detected in 200 cases of breast ductal carcinoma, all of which were invasive ductal carcinoma. Overall 52. 8% (52/180) of invasive ductal carcinoma cases showed chromosome 17 polysomy, which was correlated to HER2 gene amplification (P = 0.000) and HER-2 protein expression (P=0.000), and to HER2 expression combined with HER2 gene amplification (P=0.001). Chromosome 17 polysomy with or without HER2 gene amplification was also associated with high-grade nuclear atypia (P = 0.012 or P = 0.010) and lymphatic metastasis (P = 0.002 or P = 0.009 ). However, chromosome 17 polysomy with or without HER2 gene amplification was not correlative with the age of patients (P = 1. 000 or P = 0. 415).

CONCLUSIONChromosome 17 polysomy may be related to the nuclear atypia, metastasis, HER2 gene amplification of invasive ductal carcinoma and thus a worse prognosis of the patients.

Breast Neoplasms ; genetics ; pathology ; Carcinoma, Ductal ; genetics ; Chromosome Aberrations ; Chromosomes, Human, Pair 17 ; genetics ; Gene Amplification ; Gene Dosage ; Gene Expression Regulation, Neoplastic ; genetics ; Genes, erbB-2 ; genetics ; Humans

OBJECTIVETo study whether N, N'-di-(m-methylphenyi)-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboamide (ZGDHu-1) inhibits proliferation and induces apoptosis in human lung carcinoma cell line EBC-1 cells and its molecular mechanism.

METHODSDifferent concentrations of ZGDHu-1 and different times of culture were used to treat EBC-1 cells in vitro. The inhibition of proliferation was measured by BrdU-ELISA. Cell apoptosis was detected by Annexin V/PI staining and cellular DNA fragmentation ELISA. Phosphorylated p38MAPK and STAT3 were examined by flow cytometry. The protein expressions of bcl-2, bax, p53, Fas, and caspase-3 were detected by Western blot analysis.

RESULTSZGDHu-1 inhibited EBC-1 cell proliferation within a certain range of treating times and does, with a 24 h IC(50) of (295 ± 25) ng/ml, 48 h of (112 ± 8) ng/ml and 72 h of (23 ± 2) ng/ml. The EBC-1 cell apoptosis was confirmed by Annexin V/PI labeling and cellular DNA fragmentation ELISA in a dose-related manner. When EBC-1 cells were treated with 50, 200, and 500 ng/ml ZGDHu-1 for 48 h, the expression rates of phosphor-p38MAPK protein were 67.4%, 88.2%, 91.1%, respectively, and that of the control was 10.6%. That of STAT3 protein were 56.5%, 43.6% and 34.6%, respectively, and that of the control was 89.1%. The expression of bax, p53 and Fas protein was significantly increased, that of bcl-2 was not changed, and that of caspase-3 was significantly decreased by the ZGDHu-1 treatment.

CONCLUSIONZGDHu-1 can inhibit proliferation and induce apoptosis in EBC-1 cells. The mitochondrial pathway mediated by Fas may be one of its mechanisms. The apoptosis of EBC-1 cells may associate with up-regulation of phosphor-p38MAPK and down-regulation of phosphor-STAT3 in the cells.

Apoptosis ; drug effects ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; DNA Fragmentation ; Heterocyclic Compounds, 1-Ring ; administration & dosage ; pharmacology ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; STAT3 Transcription Factor ; metabolism ; Tumor Suppressor Protein p53 ; metabolism ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism