Enhancing the Strength of Conventional Glass Ionomer Cements Using Nanomaterials

Abstract

Glass Ionomer Cements (GICs) are a dental restorative material with a variety of
uses. They exhibit fluoride release, biocompatibility, adhesion to tooth structure and tooth coloured aesthetics making them useful for anterior restorations. However, they suffer from low strength in comparison to other restorative materials available and, due to the phasing down of dental amalgam, there is a need for strong alternatives. Nanostructures can be used to strengthen or reinforce materials, one mechanism being the absorption of energy via crack propagation in a failing material. Synthesised hydroxyapatite nanofibers (HANFs) and commercially available halloysite nanotubes (HNTs) were selected as potential reinforcing agents due to their biocompatibility, reported strength enhancing properties and anticipated chemical interactions with the GIC. HANFs were found to be vulnerable to the low pH that occurs during the setting reaction of the GIC and may have been dissolved, destroying their fibrous morphology. HNTs were more acid resistant but exhibited large amounts of agglomeration and thus required milling to disperse them throughout the GIC. Substituting 5% HNTs into a commercial GIC increased the compressive strength by over 30% creating a commercially potentially viable route to GIC reinforcement. Other important clinical properties such as handling properties, wear resistance, fluoride release, hardness and diametral tensile strength were also investigated.

Date of Award	25 Jun 2019
Original language	English
Awarding Institution	The University of Bristol
Supervisor	Lisa McNally (Supervisor) & Michele E Barbour (Supervisor)