title: Laboratory tests for assessing adaptability and stickiness of dental composites.
abstract: OBJECTIVE
  Handling (stickiness, adaptability) of a dental composite does strongly influence quality and success of a dental restoration. The purpose was to develop an in vitro test, which allows for evaluating adaptability and stickiness.
  
  
  METHODS
  15 dentists were asked for providing individual assessment (school scores 1-6) of five dental composites addressing adaptability and stickiness. Composites were applied with a dental plugger (d=1.8 mm) in a class I cavity (human tooth 17). The tooth was fixed on a force gauge for simultaneous determination of application forces with varying storage (6/25°C) and application temperatures (6/25°C). On basis of these data tensile tests were performed with a dental plugger (application force 1N/2N; v=35 mm/min) on PMMA- or human tooth plates. Composite was dosed onto the tip of the plugger and applied. Application and unplugging was performed once and unplugging forces (UF) and length of the adhesive flags (LAF) were determined at different storage (6/25°C) and application temperatures (25/37°C). Unplugging work (UW) was calculated from area of UF and LAF data.
  
  
  RESULTS
  The individual assessment revealed significantly different temperature-dependent application forces between 0.58 N and 2.23 N. Adaptability was assessed between 2.1 and 2.8 school scores. Stickiness varied significantly between the materials (scores: 2-3.2). UW differed significantly between the materials with values between 3.20 N mm and 37.83 N mm. Between PMMA substrate or tooth slides and between 1N or 2N application force only small UW differences were found.
  
  
  CONCLUSIONS
  The presented in vitro unplugging work allows for an in vitro estimation of the handling parameters adaptability and stickiness.
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Germany. Electronic address: Martin.Rosentritt@klinik.uni-regensburg.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Rosentritt
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Buczovsky
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Behr
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Preis
mesh_terms: D000268:Adhesiveness; D003188:Composite Resins; D008422:Materials Testing; D013718:Tensile Strength
chemical_list: D003188:Composite Resins
keywords: Adaptability; Application; Composite; Flow; Handling; Rheology; Stickiness