title: Interface evaluation after manual and ultrasonic insertion of standardized class I inlays using composite resin materials of different viscosity.
abstract: OBJECTIVE
  The aim of the present study was to investigate the effect of manual and ultrasonic insertion of standardized class I inlays (Cerana) using three composite resin materials of different viscosity (Tetric Flow, Tetric, and Tetric Ceram) on time to seat inlays, film thickness, and filler distribution within the materials.
  
  
  METHODS
  In a preliminary test, mean loads for manual and ultrasonic insertion were measured using the high viscosity composite resin material (Tetric Ceram). These loads were then applied with all composite resin materials to evaluate the times required to seat the inlays. In addition, film thickness was assessed using scanning electron microscopy, and filler distribution (wt% silicon, barium, ytterbium) was monitored using energy-dispersive spectroscopy.
  
  
  RESULTS
  Ultrasonic insertion significantly reduced mean load applied to seat inlays (6.4+/-1.4 N; mean+/-SD) as compared to manual insertion (18.9+/-3.1 N; p < 0.001). Using an ultrasonic device, times for insertion values were significantly lower in the high and medium viscosity composite resin material groups compared to manual insertion (p < 0.05). The widest film thickness was recorded for the high viscosity composite resin material in combination with manual insertion (p < 0.05). However, when ultrasound was applied, there was no difference in film thickness between the three materials at any levels. Furthermore, the analysis of filler distribution revealed no significant differences between groups.
  
  
  CONCLUSIONS
  Highly filled viscous composite resin materials may be used in combination with the ultrasonic insertion technique without untoward effects on film thickness or filler distribution.
authors.affiliation: Clinic for Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zurich, Switzerland. patrick.schmidlin@zzmk.unizh.ch
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: Matthias
authors.initials: M
authors.lastname: Zehnder
authors.forename: Christina
authors.initials: C
authors.lastname: Schlup-Mityko
authors.forename: Till N
authors.initials: TN
authors.lastname: Göhring
mesh_terms: D001464:Barium / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000145:classification*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry; D004577:Electron Probe Microanalysis; D006801:Humans; D007284:Inlays / Q000145:classification / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D012825:Silicon / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014465:Ultrasonics; D014783:Viscosity; D015018:Ytterbium / Q000737:chemistry
chemical_list: C113675:Cerana; D003188:Composite Resins; D003764:Dental Materials; C090969:Tetric; C121818:Tetric ceram; C452226:tetric flow composite resin; D001464:Barium; D015018:Ytterbium; D012825:Silicon