title: Dentin erosion simulation by cantilever beam fatigue and pH change.
abstract: Exposed root surfaces frequently exhibit non-carious notches representing material loss by abrasion, erosion, and/or abfraction. Although a contribution from mechanical stress is often mentioned, no definitive proof exists of a cause-effect relationship. To address this, we examined dimensional changes in dentin subjected to cyclic fatigue in two different pH environments. Human dentin cantilever-beams were fatigued under load control in pH = 6 (n = 13) or pH = 7 (n = 13) buffer, with a load ratio (R = minimum load/maximum load) of 0.1 and frequency of 2 Hz, and stresses between 5.5 and 55 MPa. Material loss was measured at high- and low-stress locations before and after cycling. Of the 23 beams, 7 withstood 1,000,000 cycles; others cracked earlier. Mean material loss in high-stress areas was greater than in low-stress areas, and losses were greater at pH = 6 than at pH = 7, suggesting that mechanical stress and lower pH both accelerate erosion of dentin surfaces.
authors.affiliation: UCSF School of Dentistry, Box 0758, San Francisco, CA 94143, USA. stanin@itsa.ucsf.edu
authors.forename: M
authors.initials: M
authors.lastname: Staninec
authors.forename: R K
authors.initials: RK
authors.lastname: Nalla
authors.forename: J F
authors.initials: JF
authors.lastname: Hilton
authors.forename: R O
authors.initials: RO
authors.lastname: Ritchie
authors.forename: L G
authors.initials: LG
authors.lastname: Watanabe
authors.forename: G
authors.initials: G
authors.lastname: Nonomura
authors.forename: G W
authors.initials: GW
authors.lastname: Marshall
authors.forename: S J
authors.initials: SJ
authors.lastname: Marshall
mesh_terms: D003799:Dental Stress Analysis / Q000379:methods*; D003804:Dentin / Q000473:pathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D008963:Molar / Q000473:pathology; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D019237:Tooth Cervix / Q000502:physiology; D014077:Tooth Erosion