Biofilm composition and composite degradation during intra-oral wear

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13 Citations (Scopus)

Abstract

Objectives. The oral environment limits the longevity of composite-restorations due to degradation caused by chewing, salivary and biofilm-produced enzymes and acids. This study investigates degradation of two resin-composites in relation with biofilm composition in vitro and in vivo.

Methods. Surface-chemical-composition of two Bis-GMA/TEGDMA composites was compared using X-ray-Photoelectron-Spectroscopy from which the number ester-linkages was derived. Composite-degradation was assessed through water contact angles, yielding surface-exposure of filler-particles. Degradation in vitro was achieved by composite immersion in a lipase solution. In order to evaluate in vivo degradation, composite samples were worn in palatal devices by 15 volunteers for 30-days periods in absence and presence of manually-brushing with water. PCR-DGGE analysis was applied to determine biofilm composition on the samples, while in addition to water contact angles, degradation of worn composites was assessed through surface-roughness and micro-hardness measurements.

Results. In vitro degradation by lipase exposure was highest for the high ester-linkage composite and virtually absent for the low ester-linkage composite. Filler-particle surface-exposure, surface-roughness and micro-hardness of both resin-composites increased during intra-oral wear, but filler-particle surface-exposure was affected most. However, based on increased filler-particle surface-exposure, the high ester-linkage composite degraded most in volunteers harvesting composite biofilms comprising Streptococcus mutans, a known esterase and lactic acid producer. This occurred especially in absence of brushing.

Significance. Degradation during intra-oral wear of a low ester-linkage composite was smaller than of a high ester-linkage composite, amongst possible other differences between both composites. S. mutans herewith is not only a cariogenic, but also a composite-degradative member of the oral microbiome. (C) 2019 Published by Elsevier Inc. on behalf of The Academy of Dental Materials.

Original languageEnglish
Pages (from-to)740-750
Number of pages11
JournalDENTAL MATERIALS
Volume35
Issue number5
Early online date2019
DOIs
Publication statusPublished - May-2019

Keywords

  • Mutans streptococci
  • Composite resin
  • Hardness
  • Surface roughness
  • Hydrophobicity
  • Contact angle
  • Microbial composition
  • Biomaterials
  • Degradation
  • Esterases
  • STREPTOCOCCUS-MUTANS BIOFILM
  • GRADIENT GEL-ELECTROPHORESIS
  • DENTAL RESIN COMPOSITES
  • IN-VITRO
  • SURFACE-ROUGHNESS
  • ADHESION FORCES
  • BIODEGRADATION
  • RESTORATIONS
  • DENTISTRY
  • BACTERIA

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