Title: 0515 - Shape Optimization of Maxillary Anterior Resin-Bonded Fixed Partial Dentures


Yuan-Ray Chang (Presenter)
National Cheng Kung University

Chi-Lun Lin, National Cheng Kung University
Yung-Chung Chen, National Cheng Kung University


Objectives: The aim of this study was to optimize the shape of resin-bonded fixed partial dentures (RBFPD) for maxillary anterior region using an automated computational approach based on nature-inspired evolutionary algorithms.

Methods: A three-dimensional model of a left central incisor in the associated maxillary segment was constructed from cone-beam-CT images. The initial shape of a RBFPD which restored missing lateral incisor was designed using Solidworks. The assembly of the incisor, RBFPD and bone was meshed using Hypermesh. Two loading situations were evaluated. An oblique load (100 N) was applied at the lingual surface of both the lateral and central incisors and that of the lateral incisor only. The model was solved using ABAQUS for stresses at interfaces between RBFPD and incisor. The particle swarm optimization algorithm was implemented to iterate the above mentioned procedure. Retainer’s shape evolved in each iteration to minimize the debonding area (DA), where the interfacial stresses were larger than the preset bond strength of cement. Finally, the optimized design was compared with the traditional design.

Results: When loaded at both incisors, the optimal DA was 10.97mm2 and the traditional one was 15.69mm2. Meanwhile, for the preparation amount of incisor, the optimized one was 26.44mm3 and the traditional one was 37.18mm3. It's worth mentioning that the RBFPD would produce smaller DA when the load was applied at enamel rather than retainer. When loaded only at the lateral incisor, the optimized DA was 10.63mm2, and the traditional one was 12.26mm2. Meanwhile, for the preparation amount of incisor, the optimal one was 30.25mm3 and the traditional one was 37.18mm3.

Conclusions: An automated computational approach was developed and performed to find the optimal RBFPD’s retainer designs in two loading situations. The results showed that in both cases, the optimal designs would produce smaller DA and require less tooth preparation than traditional ones.


Download Image 1


  Loads at central and lateral incisors (100N each) Load only at lateral incisor (108N)
Traditional Optimal Traditional Optimal
Debonding area mm2 15.69 10.97 12.26 10.63
Preparation amount mm3 37.18 26.44 37.18 30.25

This abstract is based on research that was funded entirely or partially by an outside source:
MOST 105-2221-E-006-089

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE