title: Detection of proximal secondary caries at cervical class II-amalgam restoration margins in vitro.
abstract: OBJECTIVE
  To compare the performance of LFpen (DIAGNOdent pen) with two different wedge-shaped tips to conventional bitewing radiography (BW) for detecting proximal secondary caries at the cervical margin of amalgam restorations in vitro.
  
  
  METHODS
  Seventy-five molars with class II amalgam restorations were selected. Depending on the marginal filling extension, data was subdivided into a crown group (C), when the filling ended in enamel, and into a root group (R), when the filling ended beyond the cementum-enamel junction. Bayesian analysis including calculation of the area under the receiver operating curve (AUC) was performed. Furthermore, Spearman correlations between caries and cofactors, such as presence of plaque or stain, occlusal ditching, marginal gap size, filling overhangs, and shortfalls, were calculated. Additionally, for group R the correlation coefficient between LFpen measurements and lesion depth was calculated. Histology served as gold standard.
  
  
  RESULTS
  In group C both at the D1 and D3 levels, LFpen with two different tips showed a better performance than bitewing radiography (AUC at D1: 0.83/0.79 (LFpen) and 0.63 (BW); at D3: 0.66/0.66 (LFpen) and 0.53 (BW)). In group R, the respective AUC values were 0.53/0.56 (LF) and 0.59 (BW). A significant medium correlation was observed for occlusal ditching and proximal caries. Stain accumulation at the restoration margins especially in combination with filling overhangs interfered with LFpen readings, resulting in false positive measurements.
  
  
  CONCLUSIONS
  Compared to BW, LFpen enhances the detection of secondary caries lesions at the cervical margin of amalgam restorations that do not extend below the cementum-enamel junction.
authors.affiliation: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Switzerland. klaus.neuhaus@zmk.unibe.ch
authors.forename: K W
authors.initials: KW
authors.lastname: Neuhaus
authors.forename: J A
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: R
authors.initials: R
authors.lastname: Seemann
authors.forename: A
authors.initials: A
authors.lastname: Lussi
mesh_terms: D019540:Area Under Curve; D003723:Dental Amalgam / Q000737:chemistry*; D003731:Dental Caries / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003743:Dental Enamel / Q000000981:diagnostic imaging / Q000473:pathology; D018772:Dental Marginal Adaptation / Q000145:classification*; D003773:Dental Plaque / Q000175:diagnosis; D003793:Dental Restoration, Permanent / Q000145:classification*; D004867:Equipment Design; D005189:False Positive Reactions; D005453:Fluorescence; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D010781:Photography; D012372:ROC Curve; D016300:Radiography, Bitewing; D012008:Recurrence; D013499:Surface Properties; D019237:Tooth Cervix / Q000000981:diagnostic imaging / Q000473:pathology; D014075:Tooth Discoloration / Q000175:diagnosis
chemical_list: D003723:Dental Amalgam