Biomechanical Behaviour of Quad Zygoma Technique Using a Smooth Body Zygomatic Implant and Angled Abutments - An In Vitro Study.

Introduction: The quad zygoma technique is an alternative for patients who do not have enough bone to place zygomatic implants associated with conventional implants. The association of the quad zygoma technique with smooth zygomatic implants and angled abutments is an option, and understanding the mechanical behaviour of this combination is essential. This study aims to analyse the reliability of this technique by investigating the biomechanical behaviour of the rehabilitation of a total edentulous maxilla using the quad zygoma technique with 3.5 mm and 3.75 mm smooth body zygomatic implant diameters associated with 52° and 60° abutments.

Materials and methods: The finite element analysis (FEA) method was used to evaluate biomechanical behaviour. Three-dimensional models of maxillae, zygomatic bone, zygomatic implant, abutment, screw and the superstructure were used to assemble three models with different implant diameters and mini conical abutment angulations. The amount and distribution of stress in surrounding bone tissue, implant, abutment and abutment screws were evaluated.

Results: The peak stresses in the bone, implant, abutment and abutment screw were below the resistance limits of the materials. Higher stress was found in the system (implant, abutment and abutment screw) associated with the 60° MiniConical Abutment. Similar stress patterns were found in the two placement approaches (sinus slot and exteriorised).

Discussion: The present FEA revealed that the quad zygoma technique is biomechanically suitable and reliable regardless of the implant diameter, abutment angulation and implant placement protocol. In addition, this study can help clinicians understand stress distribution and give them more confidence in using the evaluated implant system and quad zygoma approach.