dc.contributor.author | Viita-aho, Tapio | |
dc.date.accessioned | 2021-04-09T21:02:05Z | |
dc.date.available | 2021-04-09T21:02:05Z | |
dc.date.issued | 2021-03-29 | |
dc.identifier.uri | https://www.utupub.fi/handle/10024/151447 | |
dc.description.abstract | Objectives: To characterize whether the bonding performance of resin-dentin interfaces created by universal adhesives would be affected by different extensions of H3PO4-etching using quasi-static loading tests and a modified fatigue-testing approach to more accurately predict long-term durability. Methods: Mid-coronal flat dentin surfaces with clinically relevant smear-layers were produced on sound third molars, etched with 32% H3PO4 for 0, 3 and 15 s, bonded with an ultra-mild universal adhesive (3M-ESPE) and restored with a nanofilled composite. Bonded specimens (0.8 mm2) were stored in deionized water for 24 h and sectioned into beams for microtensile testing (n=10) at 24 h and after 6 months in artificial saliva at 37 ̊C. Bar-shaped resin-dentin beams (0.9 × 0.9 × 12 mm) were tested under 4-point-flexure initially at quasi-static loads (n=22) and then under cyclic loads (n>50). The stress-life fatigue behavior was evaluated using the twin-bonded interface approach by the staircase method at 4 Hz. Fractured interfaces and the tension side of unfractured beams were evaluated under SEM, along with the micro-morphology of the etched dentin surfaces and hybrid layers. Data were analyzed by ANOVA and Tukey test and Wilcoxon Rank Sum Test (α=0.05). Results: Quasi-static loads were limited to discriminate the bonding performance of resin-dentin interfaces. Application modes significantly affected etching patterns, fatigue strength, endurance limits and hybrid layer morphology (p<0.001). Significance: Drastic reductions in fatigue strength of self-etched bonded interfaces raise concerns about the true ability of ultra-mild universal adhesives to properly bond to dentin with clinically relevant smear layers. | |
dc.format.extent | 26 | |
dc.language.iso | eng | |
dc.rights | fi=Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.|en=This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.| | |
dc.subject | Human dentin, Etching, Adhesive systems, Microtensile bond strength, Bonding, Flexural strength, Hybrid layer | |
dc.title | To etch or not to etch, Part I: On the fatigue strength and dentin bonding performance of universal adhesives | |
dc.type.ontasot | fi=Pro gradu -tutkielma|en=Master's thesis| | |
dc.rights.accessrights | suljettu | |
dc.identifier.urn | URN:NBN:fi-fe202104099993 | |
dc.contributor.faculty | fi=Lääketieteellinen tiedekunta|en=Faculty of Medicine| | |
dc.contributor.studysubject | fi=Hammaslääketieteen syventävät opinnot|en=Dentistry, Advanced Studies| | |
dc.contributor.department | fi=Hammaslääketieteen laitos|en=Institute of Dentistry| | |