Analysis of stress on mucosa and basal bone underlying complete dentures with different reliner material thicknesses: a three‐dimensional finite element study

Abstract

The aim of this study was to determine the optimal thickness of reliner material that provides the least amount of stress on thin mucosa and supporting bone in patients with complete removable dentures using a three-dimensional finite element analyses. The model was obtained from two CT scans of edentulous mandibles with dentures supported by the alveolar ridge. After virtual reconstruction, the three-dimensional models were exported to the solidworks cad software and divided into six groups based on the thickness of the reliner material as follows: (i) without material, (ii) 0·5 mm, (iii) 1 mm, (iv) 1·5 mm, (v) 2 mm and (vi) 2·5 mm. The applied load was 60 N and perpendicular to the long axis of the alveolar ridge of all the prosthetic teeth, and the mucosal thickness used was 1 mm. The analyses were based on the maximum principal stress in the fibromucosa and the minimum principal stress in the basal bone. Stress concentration was observed in the anterior zone of the mandible in the mucosa and in the bone. The maximum and minimum principal stress in the mucosa and bone, respectively, decreased, whereas the thickness of the reliner material increased until 2 mm, which transmitted the lowest stress, compared with the control. Reliner materials with a thickness of 2·5 mm showed higher stress values than those with a thickness of 2 mm. In conclusion, reliner material with a thickness of 2 mm transmitted the lowest amount of stress to the mucosa and bone in 1 mm of mucosa thickness.

The Effect of Different Thickness of Two Types of Soft Liner on Retention and Electromyography of Complete Denture

“…All the previous effect increase with the increased liner thickness as claimed by a previous study (19) that reported that the use of 2 mm thick soft liner material promoted the tendency to decrease the maximum and minimum principal stress in the mucosa and in the underlying bone than 1mm. These findings were in agreement with a study (20) that reported that the maximum and minimum principal stress in mucosa and bone decreased when the thickness of the soft liner material increased up till 2 mm liner thickness.…”

Effect of denture soft liner on mandibular ridge resorption in complete denture wearers after 6 and 12 months of denture insertion: A prospective randomized clinical study

“…[ 13 ] Thus, the use of the resilient reliner material considerably minimized the stress in the alveolar bone and mucosa. [ 33 34 35 ] According to Lima et al .,[ 34 ] the thickness of the soft liner plays a significant role in the stress distribution especially in patient with thin mucosa, 2 mm thick soft liner relined denture shows lower stress distribution to bone as compared to denture with no soft liner or soft liner of variable thickness (0.5, 1, 1.5, 2.5 mm). Taguchi et al .…”

Biomechanics of oral mucosa

“…By comparing the linear and nonlinear contacts under the denture base, a finite-element study found that while the difference was less than 20% in terms of the magnitude of the VM stress in the mucosa and claimed to be insignificant [ 184 ]. Other studies have adopted either fully bonded, fully tied or other linear contact mechanism between the denture and the mucosa, to simulate a linear transmission of occlusal forces [ 78 , 83 , 86 , 87 , 92 , 99 , 100 , 102 , 106 ]. On the other hand, while incorporating this nonlinear mechanism, most studies adopted different frictional coefficients ranging from 0 (frictionless) to 0.75 (penalty contact) [ 76 , 77 , 84 , 85 , 88 , 90 , 91 , 93 , 97 , 101 , 147 , 178 , 180 , 185 ].…”