Strain Around Implants Supporting Maxillary Overdenture with Locator-Milled Titanium Bar Versus Milled Titanium Bar Attachment: An In vitro Study

Document Type : Original Article


1 prosthodontics department, Faculty of Dentistry, Minia University.

2 Prosthodontics Department, Faculty of Dentistry, Minia University

3 Removable prosthodontics, Faculty of Dental Medicine for girls, Al-Azhar University


Aim: To assess the strain around implants supporting maxillary overdenture with locator-milled titanium bar 
versus milled titanium bar attachment. Subjects and methods: A resin maxillary 3d-printed model was
fabricated simulating a previous diagnostic cone beam computed tomography (CBCT) scan of an edentulous 
patient who received later an implant-supported overdenture. Four implants guided insertion was executed at the 
canine and 2nd premolar areas in the model with multi-unit abutments. The locator-milled titanium bar (group A) 
and milled titanium bar (group B) attachments were constructed to be screwed to the multi-unit abutments. Five 
overdentures with metal housings were fabricated in both groups. A universal testing machine was utilized in 
applying a static load of 100 N vertically at loading points (bilaterally and unilaterally). Microstrain values were 
measured around each implant using strain gauge while applying the load. Every measurement was repeated 5 
times allowing a minimum 5 min rest period between measurements allowing heat dissipation. Results: During 
unilateral and bilateral loading, the canine and premolar implants in the milled titanium bar attachment showed 
a significantly elevated microstrain values than the locator-milled titanium bar attachment. Conclusion: Within 
the limitations of this study, the locator-milled titanium bar may induce lower strain/stress around implants in 
comparison to the milled titanium bar attachment in maxillary implant-supported overdenture. 


Main Subjects