Comparing bar and double-crown attachments in implant-retained prosthetic reconstruction: a follow-up investigation

Objectives: A removable implant-retained dental prosthesis in an edentulous mandible can use telescopic crowns or a bar superstructure as anchorage elements for an overdenture. The aim of this study was to compare the clinical results for bar-anchored and telescopic crown-retained overdentures in implant prosthetic treatment of the toothless lower jaw with two or more implants placed in the intraforaminal region. Material and methods: A clinical and radiographical comparison was made of the telescope vs. the bar method for removable prosthetic rehabilitation treatments in patients with an edentulous mandible. For evaluation of the clinical data, the sulcus fluid flow rate, Periotest values, and the peri-implant bone loss were recorded. Results: In the follow-up examinations, 19 implant losses were reported between insertion and review of 328 implants. The frequency distribution of the observed loss rates showed no treatment-specific trend. In the group with bar-treated implants, failure led to 'group loss' of the whole prosthetic superstructure. Failure of one of the double-crown-stabilized full dental prosthesis could usually be adapted so that the overdenture remained usable even without re-implantation. Conclusions: After comparing all the clinical parameters evaluated, no significant difference between the stabilization of full dentures via conus and telescopic crowns and bar-anchored dentures could be found. The choice of one particular method remains the decision of the professional treating the patient.