The Effects of Restorations and Loading of Abfraction Lesions

Objectives: The aim of this work was to evaluate the mechanical behavior of a maxillary second premolar with different abfraction lesions restored with two composites with distinct Young's modulus, using the three-dimensional finite element method. Methods: The following models were simulated and analyzed: Intact tooth (I); teeth with V-shaped abfraction lesions with 0.5mm (A1), 1.0mm (A2) and 1.5mm (A3) of depth without restorations and when restored with composite of low (L) and high (H) Young's modulus. The models were subjected to a non-functional load of 105 N applied obliquely to the long axis in two different directions (F1 and F2): F1 was applied on vestibular cusp and F2 on palatal cusp. The maximum principal stress was analyzed to estimate the structures failure by comparing tensile stresses with known values of tensile strength. Results: The stress distribution on these lesions was altered by the presence of a restoration with L and H. All lesions presented better stress distribution when restored with L and the load applied on palatal cusp, while stress amplification was observed when the load was applied on vestibular cusp. Conclusion: This study showed better performance of composites with low Young's modulus for restorative treatment of abfraction lesions, although these results were influenced by the type of load simulated, suggesting that occlusal adjustment should also be considered as a part of the treatment.