title: Margin Integrity and Secondary Caries of Lined or Non-lined Composite and Glass Hybrid Restorations After Selective Excavation In Vitro.
abstract: OBJECTIVE
  For deep carious lesions, selective carious tissue removal (leaving soft dentin close to the pulp) is suggested. Afterward, different restoration materials, such as resin composites or glass hybrids (GHs), can be placed. Many dentists also apply setting or non-setting calcium hydroxide liners before restoration. We compared margin integrity and susceptibility for secondary caries in differently restored premolars in vitro.
  
  
  METHODS
  In 48 extracted human premolars, artificial residual lesions were induced on pulpo-axial walls of standardized cavities. Teeth were restored using a GH (Equia Forte) or adhesively placed resin composite restoration (OptiBond FL and Tetric EvoCeram) without any liner (RC), resin composite restoration with a non-setting calcium hydroxide liner (RC_NCH), or resin composite restoration with a setting calcium hydroxide liner (RC_SCH). After thermomechanical cycling, groups (n=12) were compared regarding their gingivocervical margin integrity (proportion of irregularities, microgaps, gaps >5 μm, overhangs). Teeth were then submitted to a continuous culture Lactobacillus rhamnosus biofilm model. After 14 days, bacterial numbers in biofilms, along tooth-restoration margins and mineral loss (ΔZ) of secondary lesions, were determined.
  
  
  RESULTS
  GH and RC_NCH showed significantly higher proportions of irregularities than RC and RC_SCH (p<0.05/Mann-Whitney). GH also showed significantly more gaps than alternative restorations (p<0.05). Bacterial numbers and ΔZ did not differ significantly between groups (p>0.05).
  
  
  CONCLUSIONS
  GH and composites lined with non-setting calcium hydroxide showed reduced margin integrity compared with non-lined composites or composites lined with setting calcium hydroxide. This did not increase susceptibility for secondary caries.
authors: F
authors: F
authors: Schwendicke
authors: Jlm
authors: J
authors: Kniess
authors: S
authors: S
authors: Paris
authors: U
authors: U
authors: Blunck
mesh_terms: D001641:Bicuspid; D018441:Biofilms; D002126:Calcium Hydroxide / Q000627:therapeutic use; D003188:Composite Resins / Q000627:therapeutic use; D003731:Dental Caries / Q000209:etiology* / Q000628:therapy*; D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation / Q000379:methods*; D018772:Dental Marginal Adaptation; D005899:Glass Ionomer Cements / Q000627:therapeutic use; D006801:Humans; D066298:In Vitro Techniques; D019279:Resin Cements
chemical_list: D003188:Composite Resins; C000614715:EQUIA composite; D005899:Glass Ionomer Cements; C469607:OptiBond FL; D019279:Resin Cements; C501891:Tetric EvoCeram; D002126:Calcium Hydroxide