title: Development of a nondestructive compliance test for resilient denture liners.
abstract: OBJECTIVE
  Resilient denture liners are prescribed for patients who cannot adjust to hard-based dentures because of a thin mucosa or severe alveolar ridge resorption. A nondestructive test to evaluate compliance of new soft liner materials will be useful in clinical trials. The purpose of this study was to evaluate a nondestructive compliance testing technique designed to characterize long-term, silicone-based resilient denture liner materials.
  
  
  METHODS
  Samples of thicknesses of 1.1, 2.2, 3.3, and 4.4 mm of 2 materials (MPDS-SL [Lai Laboratories, Inc, Burnsville, MN] and Molloplast-B [Buffalo Dental, New York, NY]) were assessed for compliance using a closed-loop servohydraulic testing system, applying a 3 lb force following a squarewave pattern; force and position values were recorded using a storage oscilloscope. The oscilloscope values were analyzed using computer software to determine compliance values. The effect of material thickness was examined by testing wedges of the 2 materials.
  
  
  RESULTS
  The testing technique used showed that differing thicknesses had significantly different compliance values (p <.0001). In the materials used to evaluate the technique, MPDS-SL behaved more elastically than did Molloplast-B (p <.0001). Material thicknesses beyond 2.2 mm did not increase compliance, although MPDS-SL had a steeper thickness-compliance curve than Molloplast-B.
  
  
  CONCLUSIONS
  The method used to test compliance proved to be sufficiently sensitive to distinguish between 2 materials and between varying thicknesses. The sensitivity and nondestructive nature of this test show its suitability for clinical evaluation of resilient denture liners.
authors.affiliation: School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA. pesun001@tc.umn.edu
authors.forename: I J
authors.initials: IJ
authors.lastname: Pesun
authors.forename: A
authors.initials: A
authors.lastname: Villar
authors.forename: J S
authors.initials: JS
authors.lastname: Hodges
authors.forename: R
authors.initials: R
authors.lastname: DeLong
authors.forename: J H
authors.initials: JH
authors.lastname: Lai
authors.forename: D
authors.initials: D
authors.lastname: Schneider
mesh_terms: D000704:Analysis of Variance; D019540:Area Under Curve; D001672:Biocompatible Materials / Q000737:chemistry; D003187:Compliance; D003764:Dental Materials / Q000737:chemistry*; D003822:Denture Liners; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004548:Elasticity; D006244:Hardness; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods; D009991:Oscillometry / Q000295:instrumentation; D012680:Sensitivity and Specificity; D012826:Silicone Elastomers / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D012984:Software; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003764:Dental Materials; D004129:Dimethylpolysiloxanes; C020964:MDX 4-4210; D012826:Silicone Elastomers; D012828:Silicones