Effect of the restorative technique on load-bearing capacity, cusp deflection, and stress distribution of endodontically-treated premolars with MOD restoration

Abstract

Objectives To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Materials and Methods Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with α = 5%. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. Results MP showed the highest cusp ( p = 0.027) deflection (24.28 ± 5.09 µm/µm), followed by FGP (20.61 ± 5.05 µm/µm), CR (17.72 ± 6.32 µm/µm), and GIC (17.62 ± 7.00 µm/µm). For load-bearing, CR (38.89 ± 3.24 N) showed the highest, followed by GIC (37.51 ± 6.69 N), FGP (29.80 ± 10.03 N), and MP (18.41 ± 4.15 N) ( p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. Conclusions There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.

Biomechanical Analysis of a Custom-Made Mouthguard Reinforced With Different Elastic Modulus Laminates During a Simulated Maxillofacial Trauma

“…In observing Figure 2, it is possible to see that enamel concentrated different amounts of tensile stresses. Unlike other studies, this failure criterion was selected to highlight possible areas of tooth fractures, 23 and not just a general result of the resulting stresses. It is clearly possible to observe that the mouthguard with extremely flexible reinforcement (1 MPa) presents the worst result with the buccal enamel totally involved in larger areas of stress concentration.…”

Computer Aided Design Modelling and Finite Element Analysis of Premolar Proximal Cavities Restored with Resin Composites

“…A first upper premolar model, previously validated [ 12 ], was imported into the computer aided design (CAD) software (version 4.0 SR8, McNeel North America, Seattle, WA, USA) as a standard model for all simulations. Different parts of the tooth, including pulp, dentin, enamel, periodontal ligament, cancellous bone and cortical bone were designed in this present study.…”

“…In order to study some complex problems, the finite element method can be used for quantitative and qualitative analysis of the mechanical behavior of dental structures [ 11 , 12 ]. Thus, the objective of this study was to evaluate the stress under vertical occlusal loading and polymerization shrinkage stress in five different models of class II cavities adhesively restored with conventional or bulk-fill flowable resin composites by means of finite element analysis (FEA).…”

Stress Concentration of Endodontically Treated Molars Restored with Transfixed Glass Fiber Post: 3D-Finite Element Analysis

“…In addition, the elastic modulus of post and the direct restorative material must be compatible with the root dentin to reduce the possibility of fracture [ 7 ], as well as the root stress magnitude during chewing loads. Aiming to improve the beneficial effects of GFP usage in weakened teeth, several studies have investigated how different clinical parameters can modify the mechanical response during loading, such as GFP geometries, relining, position, and length.…”