Introduction: Strain around labially inclined implants retaining mandibular overdentures with ti–si attachments is still unclear.
Objective: To evaluate strain around labially inclined implants retaining mandibular overdentures by using ti-si attachments
Material and methods: Two mandibular epoxy models were constructed. Resilient soft lining material was used to simulate resilient edentulous ridge mucosa. The epoxy models were scanned. Two dummy implants were inserted in canine regions using CAD CAM surgical guides with the following degrees of labial inclinations: group A (control); 0°, group B; 17.5°. Mandibular overdentures were constructed over the models and connected to the models with Ti Si attachments with retentions Sil 400g/4 Newton. Strain measurements were performed under central and unilateral loading using Universal testing machine.
Results: In a comparison of group A and group B under central loading, no significant difference of microstrain was detected around the implants. Microstrain around two labially inclined implants increase as labial implant inclination increases. The increased strains with inclined implants became more evident with unilateral loading than central loading. Stresses were recorded at lingual, and less stresses were recorded at distal for both groups.
Conclusions: In both groups vertical and inclined implant under central and unilateral loading, the highest microstrain was recorded at the lingual and mesial sides of the implant. While the lowest was recorded at distal of the implant.
In comparing the two groups no significant difference was found with central loading while, with unilateral loading significant increase in microstrain was recorded in the inclined implants group.