Randomized Clinical Trial comparing clinical adjustment times of CAD/CAM screw‐retained posterior crowns on ti‐base abutments created with digital or conventional impressions. One‐year follow‐up
Wiebe Derksen, Ali Tahmaseb, Daniël Wismeijer
Abstract
OBJECTIVES: The purpose of this randomized clinical trial was to compare the required time of potential clinical adjustments of posterior screw-retained monolithic zirconia implant retained crowns based on intraoral optical scanning (IOS) or conventional impressions. MATERIALS AND METHODS: TDS) and a conventional (polyether) pick-up impression. Randomization was performed after impression taking and patients were to receive either a crown based on the digital or the conventional impression. The time required for adjustments at placement was recorded. Additionally, restoration survival and mechanical complications with a follow-up of one year were documented. RESULTS: Thirty two patients with 45 implants were included: 23 restorations in the test (IOS) and 22 in the control (conventional) group. The average adjustment time was 3.35 min (SD ± 3.38, range: 0-11 min) for the digital versus 6.09 min (SD ± 4.63, range: 0-18 min) for the conventional impressions (p = .039). A proper fit (no adjustments required) was achieved 39,1% in the digital and 18,2% conventional group respectively. All 45 restorations could be placed within the two planned appointments and only two minor mechanical complications occurred during the first year of function. CONCLUSIONS: The use of IOS resulted in shorter adjustment times at try-in than conventional impressions for solitary CAD/CAM implant restorations. Screw-retained solitary monolithic zirconia restorations on ti-base abutments show low complication- and survival rates in the short term.