Effect of denture attachment systems on peri-implant bone strain and dislodgement angle in 2-implant-retained overdentures under posterior upward displacement
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Published on: February 23, 2024
Sidarat Chinokul1, Krid Kamonkhantikul1, Woraporn Homsiang2
1Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
Purpose:
To evaluate strains generated by different denture attachment systems, peri-implant sites, and retention levels under 3-mm posterior upward displacement in 2-implant-retained overdentures and to evaluate dislodgement angles.
Materials And Methods:
Four attachment groups (LOCATOR with standard-range insert (LOC), LOCATOR with extended-range insert (LOE), LOCATOR R-Tx with standard-range insert (LOR), and Novaloc (NOV)), each with three retention levels, were tested. Peri-Implant strains were recorded during simulated posterior upward displacement until complete insert dislodgement. Dislodgement angles were also measured. Strain data were analyzed by three-way mixed ANOVA, and dislodgement angles were analyzed by two-way ANOVA (α = 0.05).
Results:
A significant interaction between attachment system and peri-implant site was found for strain (p < 0.001). The NOV group exhibited significantly higher strain values than the other groups at each site, whereas no differences were observed among the LOC, LOE, and LOR groups. Across systems, the mesial site exhibited the highest strain values. For dislodgement angle, significant main effects were found for attachment system (p < 0.001) and retention level (p = 0.002). The LOR group exhibited the greatest dislodgement angle, followed by the LOC, LOE, and NOV groups. High retention resulted in significantly lower dislodgement angle than medium (p = 0.002) and low retention (p = 0.021), whereas there was no difference between medium and low retention (p = 1.00).
Conclusions:
Attachment system significantly affected peri-implant strain and dislodgement angle under posterior upward displacement. The NOV attachment exhibited the highest peri-implant strain, particularly at the mesial site. Retention insert level did not significantly affect the peri-implant strain but did affect dislodgement angle. The LOR attachment demonstrated the greatest dislodgement angle, whereas the NOV attachment showed the lowest dislodgement angle.
