Effects of dental implant diameter and tapered body design on stress distribution in rigid polyurethane foam during insertion

• Published in: Medical engineering & physics 2024-07, Vol.129, p.104181, Article 104181
• Main Authors: Yang, Baixuan, Landa, Ainara Irastorza, Heuberger, Peter, Ploeg, Heidi-Lynn
• Format: Article
• Language: English
• Subjects: Analytical model; Anchorage; Dental implant; Dental Implants; FEA; Finite Element Analysis; Insertion; Materials Testing; Polyurethanes - chemistry; Stress, Mechanical; Torque
• ISSN: 1350-4533; 1873-4030; 1873-4030
• DOI: 10.1016/j.medengphy.2024.104181

•Dental implant anchorage was investigated by experiments, analytical and FE models.•Diameter increased normalized insertion torque and contact for tapered implant.•However, diameter did not affect these measures for parallel-walled implants.•Tapered design distributed PU foam stress further away from the thread.•This study demonstrated PU foam compression during insertion for tapered implants. Anchorage, evaluated by the maximum insertion torque (IT), refers to mechanical engagement between dental implant and host bone at the time of insertion without external loads. Sufficient anchorage has been highly recommended in the clinic. In several studies, the effects of implant diameter and taper body design under external loading have been evaluated after insertion; however, there are few studies, in which their effects on stress distribution during insertion have been investigated to understand establishment of anchorage. Therefore, the objective of this study was to investigate the effects of dental implant diameter and tapered body design on anchorage combining experiments, analytical modeling, and finite element analysis (FEA). Two implant designs (parallel-walled and tapered) with two implant diameters were inserted into rigid polyurethane (PU) foam with corresponding straight drill protocols. The IT was fit to the analytical model (R2 = 0.88–1.0). The insertion process was modeled using explicit FEA. For parallel-walled implants, normalized IT and final FEA contact ratio were not related to the implant diameter while the implant diameter affected normalized IT (R2 = 0.90, p < 0.05, β1 = 0.20 and β2 = 0.93, standardized regression coefficients for implant diameter and taper body design) and final FEA contact ratio of tapered implants. The taper design distributed the PU foam stress further away from the thread compared to parallel-walled implants, which demonstrated compression in PU foam established by the tapered body during insertion.