Stress Analysis of Zygomatic Implants on the Augmented Maxillary Sinus: Is It Necessary to Graft?

PURPOSE: Zygomatic implants are becoming an ideal therapy with advanced implant-supported prosthetic treatment for the posterior atrophic maxilla. The purpose of this study is to examine the quantity and distribution of stress, which was caused by zygomatic implants placed using intrasinus method with or without augmentation to the atrophic posterior maxilla. MATERIALS & METHODS: In this study, 3-dimensional atrophic edentulous maxilla models with and without sinus augmentation are designed with computer-aided programs. Stress analysis was carried out on the created computer models for maxillary alveolar cortical bone, for cortical bone in the zygomaticomaxillary suture, and for zygomatic spongy bone at the apex of the zygomatic implant and for metal substructure of Von Misses stress data. RESULTS: Having augmented the maxillary sinus with graft, it was observed that after the loading especially in the posterior region, the tensile and compressive stresses on the alveolar crest was distributed more homogeneously and the stress generated on the cortical bone was reduced through the graft. CONCLUSION: Although zygomatic implants are graftless solutions for athrophic maxilla, sinus augmentation will be useful for bearing stress around the implants.