Simulating Adhesive Damage in Different Filling Methods for Class V Restorations Under Polymerization Shrinkage and...

This study aimed to evaluate the impact of filling techniques (bulk filling and incremental filling) on adhesive damage by finite element analysis using a cohesive zone model.

A mandibular first premolar with a Class V cavity and its periodontal tissues were established. Tooth models were restored with different filling techniques: single increment filling (Bulk) as the control group, parallel incremental filling (PI), oblique incremental filling with the first layer placed on the incisal surface (OII), and oblique incremental filling with the first layer placed on the gingival surface (OIG). The adhesive damage at the cavity-restoration interface was represented by a cohesive zone model. Polymerization shrinkage was simulated to induce shrinkage pre-stress, followed by occlusal forces.

Under polymerization shrinkage, incremental filling techniques could effectively mitigate the expansion of the damage area but cannot reduce the damage extent. Incremental filling techniques could effectively alleviate the incremental damage caused by occlusion compared to the Bulk technique, especially the OIG technique. The PI technique exhibited the lowest adhesive damage extent and smallest range under coupled loading.

OIG technique was found to be effective in resisting adhesive damage from occlusal forces, while PI technique was recommended as the optimal method to resist adhesive damage from coupled loading.