ABSTRACT
OBJECTIVE@#To investigate influence of setting time on bond strength of different bioactive pulp capping materials with self-etch or etch-and-rinse adhesive.@*METHODS@#Sixty specimens were prepared for each of the three tested capping materials, namely mineral trioxide aggregate (MTA), iRoot BP Plus (BP) and iRoot FS (FS). Specimens of each material were divided into three groups and bonded at three setting time points of the materials respectively: initial setting time (4 h for MTA, 2 h for BP and 20 min for FS), 24 h after application and 7 d after application. The specimen surfaces of each group were treated with self-etch mode or etch-and-rinse mode of one universal adhesive (Single Bond Universal, SBU) (n=10). The bonding area was restricted to a round area with 3 mm diameter, on which composite cylinders were build up with flowable composite and light cured completely. The shear bond strength was tested immediately with a shear strength tester and fracture mode was observed under stereo microscope and recorded. The mean shear bond strength for each group was analyzed with SPSS 19.0 software ANOVA method. The surface morphology of each material was observed after setting and acid treatment under scanning electron microscope.@*RESULTS@#There was no significant difference among the three tested materials at either initial setting point or 7 d after application (P<0.05). The bond strength of MTA was significantly higher than those of BP and FS 24 h after application in both bonding modes (P<0.05). For all the three tested materials, shear bond strength was significantly higher for complete setting group than for initial setting group of the same material (P<0.05). Under scanning electron microscope, the characteristic crystal patterns could be observed on the three bioactive materials surfaces after complete setting, the size of which was bigger for MTA than for BP and FS. These features were lost to some extent after self-etch primer application or phosphoric acid etching.@*CONCLUSION@#Based on the present results, adequate bond strength can be obtained for FS at initial setting time, which is comparable with BP and MTA. This implies that clinically composite restoration can be placed over bioactive direct capping materials after shortened initial setting process in one visit.
Subject(s)
Acid Etching, Dental , Composite Resins , Dental Bonding , Dental Cements , Dental Materials , Dental Pulp Capping , Dental Stress Analysis , Dentin-Bonding Agents , Materials Testing , Resin Cements , Shear StrengthABSTRACT
<p><b>OBJECTIVE</b>To search for a new method of screening for molecular targets for androgen-dependent prostate cancer.</p><p><b>METHODS</b>We collected tissue samples and paired serum samples from 3 cases of androgen-dependent prostate cancer (ADPC) treated by surgical resection, and included another 3 samples of benign prostatic hyperplasia (BPH) tissue and normal human serum in the control group. The total proteins extracted were separated and transmembrane by two-dimensional gel electrophoresis, followed by hybridization with the sera of the patients with ADPC and those with hormone-independent prostate cancer (HIPC) as the primary antibodies. The differentially expressed proteins were compared by Western blot, analyzed by MALDI-TOF-MS mass spectrography, and verified by RT-PCR and Western blot following bioinformatic identification.</p><p><b>RESULTS</b>This modified method exhibited a significantly better effect in displaying differentially expressed proteins, by which 12 differentially expressed protein spots were identified, including Beclin1, glutathione S-transferase P (GSTP1-1), ZBTB7, dihydrodiol dehydrogenase 2 (DDH), enolase (ENO1), glucose-dependent insulin-releasing peptide receptor (GIPR), Mn-superoxide dismutase (MnSOD), phosphoglycerate mutase 1 (PGAM1), amino-peptidyl-prolyl cistrons isomerase (PPIA), and phospholipid-PE-binding protein (PEBP). The mRNA and protein expressions of Beclin1 were significantly down-regulated in androgen-dependent prostate cancer tissues.</p><p><b>CONCLUSION</b>This modified serum-guided immunoblotting technique has provided a new method for clarifying the molecular mechanisms of the occurrence and progression of HIPC, in which Beclin1-mediated autophagy may play a key role.</p>