Delgado, António HS;
(2021)
Characterization of dental bonding systems and commercial versus novel self-adhesive restoratives.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
Contemporary materials designed to replace lost tooth tissues due to caries include resin-based composites. These require bonding systems to bond to tooth substrates. As their use involves multiple steps, is technique sensitive and prone to degradation, they need improvement and simplification. Recently, self-adhesive materials were developed but are yet to overcome difficulties related to low surface interaction and bonding to dentine. The aim of this study was to test current commercial bonding systems and self-adhesive restorative materials in order to understand their properties. This allows optimisation and development of a competitive self-adhesive material with adequate physico-chemical properties. Four commercial bonding systems and three commercial self-adhesive materials were studied. An FTIR data model was built, to identify relative component ratios in the materials. Polymerisation kinetics, contact angles, pH, filler/solvent analysis and bond strength were assessed. Self-adhesive experimental materials were made by combining adhesion promoters (4-META or 10-MDP), a bulk monomer (UDMA) and a diluent monomer (PPGDMA) with a hybrid filler phase at a powder-liquid ratio of 3:1. The filler phase combined antibacterial poly-l-lysine and remineralising monocalcium phosphate monohydrate (MCPM) particles. Interfacial chemistry, penetration depth and in situ conversion were assessed through micro-Raman Spectroscopy, and other techniques such as FE-SEM/EDX and Confocal Microscopy were used for interfacial characterization. The novel formulation containing 10-MDP was assessed regarding stability, polymerisation, bond strength, flexural strength and modulus. Bonding systems were found to be variable in what concerns component ratios, polymerisation kinetics and mechanisms, pH and fillers. They still outperform self-adhesive composites in dentine interdiffusion due to their viscosity and chemical composition. The experimental composite is able to penetrate etched dentine and form long resin tags, with good conversion levels. The optimised formulation containing 10-MDP showed comparable conversion and good mechanical properties to formulations containing 4-META and may be a viable alternative to enhance material properties and bonding.
Type: | Thesis (Doctoral) |
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Qualification: | Ph.D |
Title: | Characterization of dental bonding systems and commercial versus novel self-adhesive restoratives |
Event: | UCL (University College London) |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Copyright © The Author 2021. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Medical Sciences > Eastman Dental Institute |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10127650 |
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