Does the transversal screw design increase the risk of mechanical complications in dental implants? A finite elements analysis

• Published in: International journal for numerical methods in biomedical engineering Vol. 35; no. 6; pp. e3205 - n/a
• Main Authors: Sánchez Lasheras, Fernando, Gracia Rodríguez, Javier, Mauvezín‐Quevedo, Mario, Martín‐Fernández, Elena, Bobes‐Bascarán, Javier, Llanos‐Lanchares, Hector, Álvarez‐Arenal, Ángel
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2019
• Subjects: axial and oblique load; Axial loads; Axial stress; biomechanical stress; Biomechanics; Bone Screws; Cancellous Bone - surgery; Complications; Cortical Bone - surgery; Dental implants; Dental Implants - adverse effects; Dental prosthetics; Dental restorative materials; Finite Element Analysis; Humans; implant‐supported prosthesis; Inclination; Jawbone; Load; Prostheses; Prosthesis Design; Risk; Risk Factors; Screws; Static loads; Stress analysis; Stress concentration; Stress distribution; Stress, Mechanical; Surgical implants; Three dimensional models; transocclusal screw; Transplants & implants; transversal screw; transocclusal screw; implant-supported prosthesis; axial and oblique load; biomechanical stress; transversal screw
• ISSN: 2040-7939; 2040-7947
• DOI: 10.1002/cnm.3205

The transversal screw was introduced in order to overcome some disadvantages of the transocclusal screw. However, its mechanical risk has not been studied sufficiently. The main purpose of this research was to assess and compare stress distribution in the screws and abutment of a single‐crown implant with transversal and transocclusal screw models. Two 3D models were assembled to analyse a single‐implant–supported prosthesis with transversal and transocclusal screws embedded in the jawbone. The crown was subjected to a static load of value 300 N with different levels of inclination. The transversal screw model, with an axial load of 15°, was the one with lowest stress values in all its components. However, the stress was greater with more inclined loads when compared with the transocclusal model. The prosthetic transversal screw showed much less stress than the rest of the components for any load inclination. The transversal screw design is the option with the lowest risk of mechanical complications, both in the prosthetic screw and in the abutment screw, when applying forces of lower inclination. The more oblique forces favoured a better biomechanical environment in the abutment and its screw in the transocclusal screw model. In this paper, it was found that, compared with the transocclusal screw model, the transversal screw model may be the choice with the lowest risk of possible mechanical complications in the prosthetic screw and in the abutment and abutment screw when loads of low inclination are applied. The behaviour of the stress levels for any of the prosthetic components is similar for both models, and these increase as the load inclination becomes greater.