title: Effects of cyclic fatigue stress-biocorrosion on noncarious cervical lesions.
abstract: OBJECTIVE
  Although there is a high prevalence of noncarious cervical lesions (NCCLs), the etiology of these lesions remains contentious.
  
  
  OBJECTIVE
  To evaluate the combined effects of cyclic fatigue stress and biocorrosion activity on NCCLs.
  
  
  METHODS
  Extracted premolar teeth were allocated into four groups (N = 10). Two groups were cyclically fatigue loaded (100 N; 72 cycles per minute; 9,200 cycles) and placed in either hydrochloric acid gel (pH = 0.1) or orange juice (pH = 4). The other two groups were stored in identical chemical solutions without fatigue load. The buccal-lingual width of each tooth was measured before and after testing. The depth of biocorrosion, normalized by the percentage change in buccolingual width, normalized by time (hour) was calculated. The data were analyzed using a two-way analysis of variance and Tukey's HSD multiple comparison test (α = 0.05).
  
  
  RESULTS
  Mean (SD) of the depth of biocorrosion values were as follows: teeth receiving fatigue loading with hydrochloric acid gel exposure (1.003%/hour [0.063]) revealed a significantly higher depth of biocorrosion than the fatigue-loaded group with orange juice exposure (0.511%/hour [0.281]) (p < 0.01). For the groups without fatigue loading, those with hydrochloric acid gel (0.022%/hour [0.006]) had a significantly higher depth of biocorrosion than the group with orange juice (0.009%/hour [0.004]) (p < 0.01). The cyclically fatigue-loaded teeth with hydrochloric acid gel had a significantly greater depth of biocorrosion than either group without fatigue loading (p < 0.001).
  
  
  CONCLUSIONS
  Cyclic fatigue stress-acidic biocorrosion had a significant effect on the depth of the NCCLs.
  
  
  CONCLUSIONS
  In order to manage the destructive NCCLs lesions properly, it is essential to understand the etiology of these lesions. The present study indicated that the combined mechanisms of cyclic fatigue stress and biocorrosion could contribute to the formation of NCCLs.
authors.affiliation: Department of Biomedical Engineering, Western New England University, Springfield, Massachusetts, USA.
authors.forename: John O
authors.initials: JO
authors.lastname: Grippo
authors.forename: Yada
authors.initials: Y
authors.lastname: Chaiyabutr
authors.forename: John C
authors.initials: JC
authors.lastname: Kois
mesh_terms: D001628:Beverages / Q000009:adverse effects; D001641:Bicuspid / Q000187:drug effects / Q000473:pathology*; D001696:Biomechanical Phenomena; D001732:Bite Force; D032084:Citrus sinensis; D003343:Corrosion; D003743:Dental Enamel / Q000187:drug effects / Q000473:pathology; D003804:Dentin / Q000187:drug effects / Q000473:pathology; D005638:Fruit; D006801:Humans; D006851:Hydrochloric Acid / Q000009:adverse effects; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D009811:Odontometry / Q000379:methods; D016062:Porosity; D019237:Tooth Cervix / Q000187:drug effects / Q000473:pathology*; D014077:Tooth Erosion / Q000139:chemically induced / Q000473:pathology*; D057085:Tooth Wear / Q000209:etiology / Q000473:pathology*
chemical_list: D006851:Hydrochloric Acid