Comparative analysis of unilateral removable partial denture and classical removable partial denture by using finite element method

Abstract

Introduction. Various mobile devices are used in the therapy of unilateral free-end saddle. Unilateral dentures with precise connectivity elements are not used frequently. In this paper the problem of applying and functionality of unilateral freeend saddle denture without major connector was taken into consideration. Objective. The aim was to analyze and compare a unilateral RPD (removable partial denture) and a classical RPD by calculating and analyzing stresses under different loads. Methods. 3D models of unilateral removable partial denture and classical removable partial denture with casted clasps were made by using computer program CATIA V5 (abutment teeth, canine and first premolar, with crowns and abutment tissues were also made). The models were built in full-scale. Stress analyses for both models were performed by applying a force of 300 N on the second premolar, a force of 500 N on the first molar and a force of 700 N on the second molar. Results. The Fault Model Extractor (FME) analysis and calculation showed the complete behavior of unilateral removable partial denture and abutments (canine and first premolar), as well as the behavior of RPD under identical loading conditions. Applied forces with extreme values caused high stress levels on both models and their abutments within physiological limits. Conclusion. Having analyzed stresses under same conditions, we concluded that the unilateral RPD and classical RPD have similar physiological values.

Uvod. U lečenju jednostrane krezubosti koriste se različiti oblici mobilnih nadoknada. Jednostrane kompleksne proteze sa preciznim veznim elementima nisu često u upotrebi. Radi rasvetljenja problema jednostrano slobodnog sedla i primene proteze koja ne poseduje veliku spojnicu, u ovom radu je prikazano istraživanje funkcionalnosti ove manje poznate nadoknade. Cilj rada. Cilj rada je bio da se ispitaju i uporede dobijeni naponi jednostrane kompleksne i konvencionalne parcijalne skeletirane proteze pod opterećenjem. Metode rada. U kompjuterskom programu CATIA V5 napravljeni su trodimenzionalni modeli jednostrane kompleksne proteze s odgovarajućim potpornim strukturama (retencioni zubi - očnjak i prvi premolar s namenskim krunicama, alveole i parodontalni prostor) i klasične skeletirane proteze s livenim kukicama. Radi validnosti dobijenih rezultata, modeliranje je obavljeno u prirodnoj veličini. Primenom metode konačnih elemenata izvršena je komparativna analiza vrednosti dobijenih napona pri opterećenju silama od 300 N u predelu drugog premolara, 500 N u predelu prvog molara i 700 N u predelu drugog molara. Rezultati. Proračun je dao sliku ponašanja celog modela jednostrane kompleksne parcijalne proteze s retencionim zubima i sliku celog modela klasične skeletirane parcijalne proteze koje su predstavljene u obliku napona pri različitim uslovima opterećenja. Uneta opterećenja izazvala su visok nivo napona na modelu i zubima nosačima, ali u granicama fiziološke podnošljivosti. Zaključak. Naponi na potpornim strukturama jednostrane kompleksne proteze koji su nastali usled dejstva primenjenih sila bili su u podnošljivim fiziološkim granicama. U uslovima istog opterećenja primenom metode konačnih elemenata dobijaju se veoma slične vrednosti napona jednostrane kompleksne proteze i konvencionalne skeletirane proteze.