title: Marginal integrity and secondary caries of selectively excavated teeth in vitro.
abstract: OBJECTIVE
  Selective caries removal involves sealing of carious dentine beneath restorations, which might decrease their marginal integrity and increase the susceptibility for secondary caries and microleakage. The present study compared these marginal characteristics of restorations in selectively and completely excavated teeth.
  
  
  METHODS
  In 32 premolars, shallow and deep artificial lesions were created on pulpo-axial walls of mesial-distal-occlusal cavities, with mesial and distal margins located in enamel and dentine, respectively. Demineralised dentine was either removed or left before adhesively restoring the teeth (n=8), which were then submitted to thermo-mechanical cycling. The integrity of gingivo-cervical margins was assessed using scanning electron microscopy. In half of each margin, caries was induced adjacent to restorations using a continuous-culture biofilm model, and resulting lesions were evaluated using transversal microradiography. The other half of each margin was used to assess microleakage.
  
  
  RESULTS
  Integrity or microleakage of margins located in enamel did not differ significantly between groups, and bacterial biofilms did not induce distinct caries lesions in enamel. Dentinal margins in teeth with deep compared with shallow lesions showed a significantly higher proportion of marginal imperfections, gaps and microleakage (p≤0.05, Mann-Whitney/χ(2)-test). In contrast, neither marginal integrity nor microleakage differed significantly between completely and selectively excavated teeth (p>0.05). Dentinal mineral loss adjacent to restorations did not differ significantly between groups (p>0.80).
  
  
  CONCLUSIONS
  The marginal characteristics of restorations were affected by the depth of sealed or excavated lesions, but not by the performed caries excavation. This study did not find selective excavation detrimental for restoration integrity in vitro.
  
  
  CONCLUSIONS
  Selective excavation of deep lesions was shown to reduce pulpal risks, whilst leaving caries beneath restorations is feared to compromise the marginal characteristics of the subsequently placed restoration. Based on the present in vitro study, such assumptions cannot be supported.
authors.affiliation: Department of Operative and Preventive Dentistry, Charité - Universitätsmedizin Berlin, Berlin, Germany. Electronic address: falk.schwendicke@charite.de.
authors.forename: F
authors.initials: F
authors.lastname: Schwendicke
authors.affiliation: Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts Universität, Kiel, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kern
authors.affiliation: Department of Operative and Preventive Dentistry, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Blunck
authors.affiliation: Department for Conservative Dentistry and Periodontology, Christian-Albrechts Universität, Kiel, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Dörfer
authors.affiliation: Department for Conservative Dentistry and Periodontology, Christian-Albrechts Universität, Kiel, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Drenck
authors.affiliation: Department of Operative and Preventive Dentistry, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Paris
mesh_terms: D018441:Biofilms; D003188:Composite Resins / Q000737:chemistry; D003731:Dental Caries / Q000209:etiology* / Q000382:microbiology / Q000628:therapy; D003733:Dental Caries Susceptibility / Q000502:physiology; D003737:Dental Cavity Preparation / Q000379:methods; D003743:Dental Enamel / Q000473:pathology; D003763:Dental Leakage / Q000145:classification; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000379:methods*; D003804:Dentin / Q000473:pathology; D006801:Humans; D008422:Materials Testing; D008852:Microradiography / Q000379:methods; D008855:Microscopy, Electron, Scanning; D011897:Random Allocation; D012008:Recurrence; D019279:Resin Cements / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C469607:OptiBond FL; D019279:Resin Cements; C501891:Tetric EvoCeram
keywords: Biofilm; Caries removal; Marginal integrity; Microleakage; Partial; Residual caries; Secondary caries