Effects of Self-healing Microcapsules on Dental Resin Composites

  • Khaled Abid Althaqafi

Student thesis: Phd

Abstract

Dental restorations of resin-based composites mainly fail due to secondary caries and bulk fracture. Self-healing strategies in polymeric materials have been shown to enhance the mechanical properties with the ability of self-repair and crack inhibition, suggesting a prolonged life for dental composite restorations. The systematic review on self-healing dental composites (SHDCs) concluded that a healing performance of 25-80 % recovery rate of the virgin fracture toughness can been achieved based on current literature. The self-healing systems used were PUF microcapsules of DCPD and TEGDMA-DHEPT or silica microcapsules of water/polyacid healing agent. TEGDMA-DHEPT microcapsules were synthesised as they have been proven previously to be biocompatible for dental materials. Microcapsules were prepared by in situ emulsion polymerisation of PUF shells (average diameter 150-300 μm). The experimental SHDC included: Bis-GMA:TEGDMA (1:1), 1 wt% BAPO, 0.5 wt% BPO catalyst, 20 wt% SiO2 (15 nm), and (0, 2.5, 5, 7.5, 10 wt%) of microcapsules. SEM imaging of the capsular shell revealed a smooth outer surface with deposits of PUF nanoparticles which offers a rough surface that may improve resin matrix retention. FT-IR showed that microcapsules crushed with BPO catalyst had DC of up to 60.3 %. The DC of SHDC after 24 h polymerisation was 73-76 % (P>0.05), micro-hardness 22-26 VHN (P>0.05), however, the flexural strength was reduced significantly from 80 to 55 MPa with increasing microcapsules to 10 wt% in composites (P
Date of Award1 Aug 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorNick Silikas (Supervisor) & Julian Satterthwaite (Supervisor)

Keywords

  • self-healing, self-sealing, microcapsules, resin composites, dental composites

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