ABSTRACT
To evaluate the bond strength of composite resin containing or not biomaterial (S-PRG) to sound/eroded dentine. Methods: Occlusal dentin of 30 human molars (n=15) had half of its surface kept uneroded, while on the other half an erosive lesion was produced by cycling in citric acid (pH 2.3) and supersaturated solution (pH 7.0). On both eroded (ED) and non-eroded (SD) substrates, two restorative systems (containing or not S-PRG) were tested. Composite resin cylinders were built and, after storage in water (24h), were submitted to bond strength test. The analysis of the fracture pattern was performed under an optical microscope (40x). The obtained values of bond strength (MPa) were submitted to ANOVA (two factors) and Tukey multiple comparisons tests (p<0.05). Results: According to the results, there was difference between substrates (<0.001) and restorative materials (p=0.002) evaluated. For the microtensile bond strength, the values obtained were: SDNB (47.6±12.2 MPa), SDWB (34.1±15.8 MPa), EDNB (31.1±8.3 MPa) and EDWB (15.5±13.6 MPa), revealing a statistically significant difference in the evaluated substrates and restorative materials. Conclusion: Bond strength of eroded substrate is inferior to the sound substrate and the restorative system containing S-PRG biomaterial influences negatively the results of bonding to sound/eroded dentin (AU)
Subject(s)
Humans , Male , Female , Composite Resins , Dentin , Tooth ErosionABSTRACT
Introduction: Nowadays, there are many articles about Platelet Rich Plasma/Platelet Rich Fibrin families. A novel platelet-rich product called titanium prepared platelet-rich fibrin (T-PRF) has stronger and thicker fibrin than that of the classic glass tube prepared platelet-rich fibrin. Strong fibrin structure is important to extend the time for resorption of fibrin in-vivo, and increase the release time of growth factors. Objective: In this preliminary study of a new centrifugation method, we aimed to change the direction of fibrin formation during the platelet aggregation, and make T-PRF much denser and more resistant. According to our hypothesis, it can make it possible to use in guided bone, and guided tissue regeneration more successfully. Methods: Blood samples of 10 healthy male volunteers were collected, and four 10ml blood samples, one for each of four groups, were transferred to a Ti tube from each volunteer. The first group was centrifuged for a 20-minute period clockwise (T-PRF group), and the other groups were centrifuged for a total of 20 minutes with two-minute (2min MT-PRF group), five-minute (5 min MT-PRF group), and ten-minute (10min MT-PRF group) periods clockwise and counter-clockwise. Results: By hematoxylin and eosin stain, the 10min MT-PRF group showed a better-organized network with continuous integrity compared to the other groups. With the immunofluorescent staining, fibrin seemed thicker and better organized in the 10 min MT-PRF group. SEM examination showed more complex and denser fibrin clusters in the 10 min MT-PRF group than the other groups. Conclusion: This pilot study defines 10 min MT-PRF as a new autogenous product with superior fibrin network. Our results showed that, fibrin formation was made more organised and denser with 2-way direction centrifugation.