title: Stress Distribution under Commercial Denture Liners- A Finite Element and Clinical Analysis.
abstract: BACKGROUND
  Previous studies have shown that 20-30% of denture users have been dissatisfied with their dentures.
  
  
  OBJECTIVE
  To evaluate the stress pattern under elastic and viscoelastic denture liners using 3-Dimensional Finite Element Analysis (FEA) and its clinical correlation using a questionnaire.
  
  
  METHODS
  The study had both in-vitro and in-vivo phases. In in-vitro phase fabrication of a virtual parametric model of edentulous maxilla and dentures with overlying mucosa was made. A virtual load of 166N was analyzed at three points (Point A=anterior ridge, Point B=right posterior ridge and Point C=left posterior ridge). For the in-vivo phase, 20 edentulous patients were provided conventional complete dentures (Group-I). The dentures were lined with silicone (elastic) liners (Group-II) and acrylic resins (viscoelastic) liners (Group-III) at regular (2 months) intervals. After each reline, the patients were evaluated using food eating ability and denture assessment questionnaires. The results were statistically analyzed. The statistical analysis was done using SPSS (Statistical Package for Social Sciences) version 15.0 statistical analysis software. Other than standard statistical test Analysis of Variance (ANOVA) and Post-Hoc tests (Tukey-HSD) were used.
  
  
  RESULTS
  At loading, the in-vitro result for Groups-II and III revealed pressures of 0.074231N and 0.0678364N at Point A, 0.098764N and 0.093642N at Point B, and 0.099876N and 0.093746N at Point C respectively. The in-vivo study revealed that the mean quality of life score for different groups ranged from 23.65±4.00 (Group I) to 33.10±6.15 (Group III). The mean quality of life score for Group II was 29.50±5.08.
  
  
  CONCLUSIONS
  The viscoelastic liner provided the most uniform stress distribution and performed better than an elastic liner with hard, firm and soft foods.
authors.affiliation: Clinical Practitioner, Dental Care Oral Implantology Center and Axiss Dental Pvt., Ltd. , DLF Phase 1, Gurugram, Haryana, India .
authors.forename: Rahul
authors.initials: R
authors.lastname: Shrivastava
authors.affiliation: Assistant Professor, Department of Prosthodontics, College of Dentistry, King Khalid University , Abha, Saudi Arabia .
authors.forename: Saurabh
authors.initials: S
authors.lastname: Chaturvedi
authors.affiliation: Professor and Head, Department of Prosthodontics, Career Post Graduate Institute of Dental Sciences , Lucknow, Uttar Pradesh, India .
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Verma
authors.affiliation: Professor, Department of Prosthodontics, Career Post Graduate Institute of Dental Sciences , Lucknow, Uttar Pradesh, India .
authors.forename: Mariyum
authors.initials: M
authors.lastname: Ali
authors.affiliation: Clinical Practitioner, Dental Care Oral Implantology Center and Axiss Dental Pvt., Ltd. , DLF Phase 1, Gurugram, Haryana, India .
authors.forename: Amrita
authors.initials: A
authors.lastname: Nagendra
authors.affiliation: Assistant Professor, Department of Oral Pathology, Career Post Graduate Institute of Dental Sciences , Lucknow, Uttar Pradesh, India .
authors.forename: Mudita
authors.initials: M
authors.lastname: Chaturvedi
keywords: 3D Scanner; Denture assessment questionnaires; Node elements; Parametric model; Virtual Models