title: Effects of calcium silicate-based materials on collagen matrix integrity of mineralized dentin.
abstract: BACKGROUND
  Calcium silicate-based materials (CSMs) are used in various endodontic procedures. The present study examined whether prolonged contact of mineralized dentin with recently commercialized versions of these materials adversely affects dentin collagen matrix integrity.
  
  
  METHODS
  Dentin slabs prepared from extracted human third molars (7 × 3 × 0.3 mm) were divided into 3 groups on the basis of the material to which dentin was exposed (MTA Plus, Biodentine, untreated control dentin slabs) and the time period of exposure (24 hours, 1, 2, and 3 months; n = 6). Hydroxyproline assay was performed on each group's supernatant to quantify the collagen extraction amounts of each group per time period. Data were analyzed with two-factor repeated-measures analysis of variance and Holm-Sidak pair-wise comparisons (α = 0.05) to determine the effects of material and aging time on collagen extraction. Dentin slabs from the 3 months of aging group were demineralized for transmission electron microscopy examination of collagen matrix ultrastructural changes.
  
  
  RESULTS
  Material (P = .002), aging time (P < .001), and their interactions (P = .007) significantly affected the amount of hydroxyproline (pg/mg of mineralized dentin) extracted from mineralized dentin and were significantly correlated by power regression models. Collagen degradation was identified from the surface of dentin slabs that were in direct contact with CSMs.
  
  
  CONCLUSIONS
  Prolonged contact of mineralized dentin with CSMs has an adverse effect on the integrity of the dentin collagen matrix. However, the amount of collagen extracted was limited to the contact surface. Clinicians can continue to apply CSMs in endodontic procedures; however, caution is advised when these materials are applied to thin dentinal walls.
authors.affiliation: Department of Endodontics, Georgia Health Sciences University, Augusta, Georgia 30912-1129, USA.
authors.forename: Alaina P
authors.initials: AP
authors.lastname: Leiendecker
authors.forename: Yi-Pin
authors.initials: YP
authors.lastname: Qi
authors.forename: Allen N
authors.initials: AN
authors.lastname: Sawyer
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Niu
authors.forename: Kelli A
authors.initials: KA
authors.lastname: Agee
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Loushine
authors.forename: Roger N
authors.initials: RN
authors.lastname: Weller
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D017607:Aluminum Compounds / Q000009:adverse effects; D000704:Analysis of Variance; D017610:Calcium Compounds / Q000009:adverse effects*; D024042:Collagen Type I / Q000032:analysis* / Q000187:drug effects; D003804:Dentin / Q000737:chemistry / Q000187:drug effects*; D004338:Drug Combinations; D005109:Extracellular Matrix / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D006909:Hydroxyproline / Q000032:analysis; D046529:Microscopy, Electron, Transmission; D010087:Oxides / Q000009:adverse effects; D059748:Proteolysis; D057872:Pulp Capping and Pulpectomy Agents / Q000009:adverse effects*; D012044:Regression Analysis; D012387:Root Canal Filling Materials / Q000009:adverse effects; D017640:Silicates / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D024042:Collagen Type I; D004338:Drug Combinations; D010087:Oxides; D057872:Pulp Capping and Pulpectomy Agents; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C506393:tricalcium silicate; D006909:Hydroxyproline