BACKGROUND/AIMS

Direct restoration of root-filled premolars with cusp fractures is controversial. The aim of the present study was to compare two different direct restoration techniques with and without cuspal coverage for the restoration of root-filled two-rooted maxillary premolar without palatal cusp using three-dimensional (3D) finite element method (FEM).

MATERIAL and METHODS

Three-dimensional FEM mathematical models were used to evaluate how different restorative options changed stress distribution of the remaining dental tissues. These models were: (1) intact maxillary first premolar (control group), (2) coronal-radicular build-up restoration (CRBR) with buccal cusp coverage (BCC), (3) CRBR without BCC, (4) post-retained direct restoration (PDR) with BCC, and (5) PDR without BCC. A 100 N occlusal load was applied to calculate stress distributions. The Algor Fempro program was used for FEM analysis. von Mises stress distributions and values on the remaining enamel, dentin, and restorative materials were evaluated.

RESULTS

Regarding stresses that occurred in the enamel, models with BCC transferred lower stress than models without BCC. The lowest stress value in the enamel was observed in the control group with 24.86 MPa. The stress values of the control group, PDR, and CRBR in the dentin were 9.93, 9.68, and 9.32 MPa, respectively

CONCLUSION

The present study found out that direct cuspal coverage with resin composites appeared to be a reliable method in restoring maxillary first premolar with missing palatal cusp. Reinforcing the restoration with either post- or intraradicular extensions was both protective in the case of dentin.

Keywords: Finite element analysis, premolar, composite resins