EVALUATION OF PERIIMPLANT BONE STRAIN IN 2-IMPLANT-RETAINED OVERDENTURES WITH DIFFERENT DENTURE ATTACHMENT SYSTEMS UNDER 5-DEGREE POSTERIOR UPWARD DISPLACEMENT

Abstract

Posterior occlusal forces in 2-implant-retained overdentures may generate bending moments around the implants. However, evidence regarding strain around implants during upward displacement of denture remains limited. Two attachment systems 1) LOCATOR with standard-range inserts and 2) Novaloc were examined, each with 3 retention levels. Strain around implants was recorded under a simulated posterior upward displacement of 5 degrees. Statistical analysis was performed using a 3-way mixed ANOVA (α = 0.05). Periimplant strain was influenced by the combined effect of attachment type and measurement location (P = 0.012). The Novaloc system produced greater strain values than the LOCATOR system across all evaluated sites. Regardless of the attachment used, the mesial region consistently exhibited the highest strain. Variation in retention level did not result in significant differences in strain values. The choice of attachment system plays a significant role in determining periimplant strain under posterior upward displacement conditions. The Novaloc attachment generated higher strain, particularly at mesial sites, whereas differences in retention level did not significantly alter strain magnitude.

Keywords: Denture Attachment, Posterior Upward Displacement, Periimplant Bone Strain, Overdenture