title: Erosion and abrasion of tooth-colored restorative materials and human enamel.
abstract: OBJECTIVE
  The aim of this study was to investigate the effects of erosion and toothbrush abrasion on different restorative materials and human enamel.
  
  
  METHODS
  Human enamel and 5 kinds of tooth-colored restorative materials were used. The restorative materials included three composite resins (Filtek Silorane, Tetric EvoCeram, and Tetric EvoFlow), a polyacid-modified composite (Dyract Extra), and a conventional glass-ionomer cement (Ketac Fil Plus). For each type of the material, 40 specimens were prepared and embedded in ceramic moulds and divided into four groups (n=10): control group (C), erosion group (E), abrasion group (A), and erosion-abrasion group (EA). The specimens were subjected to six daily erosive attacks (groups E and EA; citric acid, pH 2.3, 1 min) and/or six abrasive attacks (groups A and EA; toothbrush abrasion, 100 strokes, 1 min), while the control specimens (group C) were maintained in artificial saliva. After 10-day treatment, the substance loss and surface changes were determined by surface profilometry and scanning electron microscopy.
  
  
  RESULTS
  Human enamel presented higher substance loss when compared to restorative materials. Generally, combined erosion-abrasion (EA) caused the highest substance loss, followed by erosion, abrasion, and storage in artificial saliva. Composite resin presented highest durability under erosive and/or abrasive attacks. Enamel and restorative materials showed degradation in groups E and EA through SEM observation.
  
  
  CONCLUSIONS
  Toothbrush abrasion has a synergistic effect with erosion on substance loss of human enamel, polyacid-modified composite and glass-ionomer cement. The acid- and abrasive-resistance of human enamel was lower compared to restorative materials.
authors.affiliation: Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zurich, Plattenstrasse 11, Zurich, Switzerland. hao.yu@zzmk.uzh.ch
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Florian J
authors.initials: FJ
authors.lastname: Wegehaupt
authors.forename: Annette
authors.initials: A
authors.lastname: Wiegand
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Roos
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Buchalla
mesh_terms: D019343:Citric Acid / Q000737:chemistry; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003743:Dental Enamel / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry*; D019554:Dental Restoration Wear / Q000145:classification*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008298:Maleates / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012464:Saliva, Artificial / Q000737:chemistry; D062047:Silorane Resins; D013499:Surface Properties; D014072:Tooth Abrasion / Q000209:etiology* / Q000473:pathology; D014077:Tooth Erosion / Q000209:etiology* / Q000473:pathology; D014099:Toothbrushing / Q000009:adverse effects / Q000295:instrumentation
chemical_list: D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C088486:Dyract; D005899:Glass Ionomer Cements; D008298:Maleates; D012464:Saliva, Artificial; D062047:Silorane Resins; C501891:Tetric EvoCeram; C452226:tetric flow composite resin; D019343:Citric Acid; C040964:Ketac-Fil