Analisis Distribusi Tegangan dan Pergeseran dari Gigi Tiruan Lengkap pada Kondisi Linggir Flabby dengan Berbagai Teknik Pencetakan dan Arah Beban Pengunyahan Menggunakan Finite Element Analysis

Abstract

Full edentulous patients with flabby ridge are one of the frequent case found in clinics, but it is still difficult for dentists to fabricate dentures in flabby ridges patient. Flabby ridge is a fibrous tissue with soft consistency, which when large distribution of tension apply, deformation can happened; then dentures become unstable and ill fitting and patient feel uncomfortable. Window, one step double spacer and dual tray impression techniques are techniques that is recommended in cases of flabby ridges and has an impact in stress distribution and denture displacement. Design of impression tray and impression techniques in flabby ridges cases are important factors that we should pay attention because it has a major influence in the fabrication of complete dentures for good stabilization. This study aims to analyse the stress distribution and displacement of the full denture in flabby ridge patient with several impression techniques and applied mastication forces using the FEA (Finite Element Analysis). Fabrication of three maxillary complete dentures of one fully edentulous patient with flabby ridges with three different impression techniques; window, one step double spacer and dual tray technique. The loads are then applied, to simulate individual maximum bite loads with complete dentures. A complete denture is scanned and replicated in Spaceclaim software. Then load simulations of 100 N axially and 119 N obliquely were carried out on maxillary first premolar, second premolar and first molar. Von Mises stress value and the lowest displacement was seen in complete dentures with window impression technique, then dual tray and one step double spacer. These results show that complete dentures fabricated with window impression technique has a lowest stress distribution and denture displacement in the flabby region compared to the other impression techniques; in which window impression technique is the most ideal technique can be used in fabrication of denture in patient with flabby ridge because the design of impression tray in flabby region which is opened, then when impression taking is done, impression material will not compress the flabby region that deformation will not happened ; and impression material used is the light body polyvinyl siloxane in which the consistency will not caused mucous deformation. However, one step double spacer and dual tray impression techniques can also be used in flabby ridge cases where one step double spacer impression techniques can be used in small degree of flabby region circumference and dual tray impression techniques can be used on several flabby regions in one jaw.