Combining structural-thermal coupled field FE analysis and the Taguchi method to evaluate the relative contributions of multi-factors in a premolar adhesive MOD restoration.
Level 5 - mechanism / opinion, no new human data
In silico finite element simulation with no human subjects or biological tissue testing.
PubMed 18550252 · doi:10.1016/j.jdent.2008.04.013
What was done
A validated finite element model of a premolar with an adhesive Class II mesio-occluso-distal (MOD) restoration was used to perform structural-thermal coupled field analyses. The Taguchi method was applied to evaluate the relative contributions of restorative material, cavity dimensions, adhesive layer adaptation, and load conditions on biomechanical stress during oral temperature shifts and upon return to 37 degrees C.
What was found
Thermal expansion of the restorative material dominated tooth stress values (69%) at high temperatures. Upon returning to 37 degrees C, the percentage contributions shifted, with load conditions (46%), cavity depth (32%), and cement modulus (14%) primarily driving tooth stress values. Load conditions remained the main determinant of resin cement stress regardless of temperature changes. Higher stress values occurred with composite resin, lateral loading, deeper cavities, and higher luting cement moduli.
Why it matters
This computational analysis indicates that deep MOD cavities restored with low-thermal-expansion materials (such as ceramics), low-modulus cements, and occlusal adjustments to reduce lateral force help minimize mechanical stress concentration in restored teeth.
Limits
The study is purely an in silico simulation lacking clinical or in vitro benchtop validation. The abstract reports percentage contributions but omits absolute stress values, specific material properties, and variability metrics. Clinical complexities such as cyclic fatigue, intraoral moisture degradation, and anatomic variations were not evaluated.
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