Load-Bearing Capacity of Zirconia Crowns Screwed to Multi-Unit Abutments with and without a Titanium Base: An In Vitro Pilot Study

Abstract

The static and dynamic load-bearing capacities and failure modes of zirconia crowns screwed to multi-unit abutments (MUAs) with and without a titanium base (T-base) were determined. Thirty-six monolithic zirconia crowns screwed to straight MUAs torqued to laboratory analogs (30 Ncm) were assigned to two groups (n = 18). In group A, the zirconia crowns were screwed directly to the MUAs; in group B, the zirconia crowns were cemented to the T-base and screwed to the MUAs. All specimens were aged in 100% humidity (37 °C) for one month and subjected to thermocycling (20,000 cycles). Afterwards, the specimens underwent static and dynamic loading tests following ISO 14801. The failure modes were evaluated by stereomicroscopy (20×). There was an unequivocally similar trend in the S-N plots of both specimen groups. The load at which the specimens survived 5,000,000 cycles was 250 N for both groups. Group A failed mainly within the metal, and zirconia failure occurred only at a high loading force. Group B exhibited failure within the metal mostly in conjunction with adhesive failure between the zirconia and T-base. Zirconia restoration screwed directly to an MUA is a viable option, but further studies with larger sample sizes are warranted.

Prosthetic Complications of Screw-Retained Restoration Using Multiunit Abutments Versus Intraoral Luting on Titanium Base in Implant-Supported Complete Overdentures Randomized Clinical Trial

“…Heller et al conducted a study using straight transmucosal abutments restored by crowns cemented to titanium bases while in another group placing the crowns directly onto the transmucosal abutment. The study concluded that both types of restorations were viable treatments that did not represent a statistically significant difference [20]. Titanium base designs play a major role in their uses.…”

“…For both groups, occlusion blocks 18 were constructed over the final casts for bite registration. After bite registration, the case was ready for scanning, 19 designing, 20 nesting, 21 and milling 22 (Figure 5).…”

Comparative evaluation of shear bond strength of orthodontic brackets bonded to three-dimensionally-printed and milled materials after surface treatment and artificial aging

“…After bonding, the specimens were stored at 37°C under 100% humidity for 1 month, followed by 1,000 cycles of thermocycling between 5°C and 55°C with a 30-second dwell time. 10 , 11 …”

Conventional and Digital Impression Techniques in Implant Prosthetics

“…21,44 İmplantlar arası açısal farklılıklar ile birlikte implant sayısının fazla olduğu durumlarda multi-unit abutment'lar daha avantajlıdır. 1,45 17 İmplant sistemine bağlı olarak ölçü transfer kopingleri farklı şekillerde, uzunluklarda, genişliklerde, retansiyon sistemlerinde ve derinliklerde olabilir. 47 İmplant üstü ölçülerde direkt teknikte genelde kare ölçü kopingleri kullanılırken indirekt teknikte konik kopingler implant üzerinde kalır ve laboratuvar analoğu ile birleştirilerek çalışma modeli elde etmek amacıyla model dökülür.…”