PURPOSE An in vitro study was performed to assess the effect of different degrees of clinical reduction of zirconia abutments on the failure load of clinical assemblies. MATERIALS AND METHODS Zirconia abutments (Y-TZP Ceramic Abutment, Astra Tech) were prepared with 0, 0.5, or 1 mm of external axial reduction starting 1 mm above the height-of-contour. Abutments (n = 10) were attached to impla...

STATEMENT OF PROBLEM The process of removing excess cement from subgingival margins after cementation of restorations to implant abutments may lead to scratching of the abutments or incomplete cement removal. PURPOSE The purpose of this study was to investigate and to compare the surfaces of abutments after the removal of three cements (glass ionomer, resin, and zinc phosphate) by use of thre...

The purpose of this study was to assess the effects of a modified implant abutment design on peri-implant soft and hard tissues in dogs. Three months after extraction of mandibular premolar teeth, 3 dental implants were placed in each side of the jaw using a 1-stage approach. Implants on one side of the mandible received standard abutments (control), and implants on the contralateral side recei...

Fixed partial dentures cemented to dies of adjustable mobility were subjected to repeated impacts at three different sites. Immobile abutments retained their prostheses longer than mobile abutments. Impacts that fell between the centers of rotation of the abutments were withstood longer than impacts that fell nearer the ends of the prostheses. This study failed to show a significant difference ...

PURPOSE Microgaps at the implant-abutment interface allow for microbial colonization, which can lead to peri-implant tissue inflammation. This study sought to determine the marginal accuracy of three different implant-zirconium oxide (zirconia) abutment configurations and one implant?titanium abutment configuration. MATERIALS AND METHODS Three combinations of implants with custom-made zirconi...

PURPOSE Micromotion at the implant-abutment level has been reported to be a major determinant of longterm implant success, as technical problems ranging from screw loosening to screw fracture may occur as a consequence of excessive micromotion. MATERIALS AND METHODS Following published standards, implant-abutment assemblies were fixed in a universal testing machine at a 30-degree angle. A cyc...

OBJECTIVE The purpose of this study was to determine the fracture strength of zirconium implant abutments and the torque required to unfasten the retaining screw before and after applying cyclic loading to the implant-abutment assembly. The dynamic behavior and stress distribution pattern of zirconium abutments were also evaluated. METHODS AND MATERIALS Static and cyclic loading of 7 XiVE imp...

Objectives: Due to its hardness, zirconia abutments may damage the titanium of the implant’s connection during its clinical use. This study aimed to assess the wear of the seating platforms of externally hexed titanium implants when connected to zirconia abutments comparing to titanium abutments, after thermocycling and mechanical loading (TCML). Methods: Six BNT® S4 external connection implant...

OBJECTIVES The objectives of the review were (1) to evaluate the accuracy of implant-level impressions in cases with internal and external connection abutments/reconstructions, and (2) to evaluate the incidence of technical complications of internal and external connection metal- or zirconia-based abutments and single-implant reconstructions. MATERIALS AND METHODS A MEDLINE electronic search ...

Objectives: The aim of this prospective cohort study was to compute the long-term clinical survival and complication rates of alumina-toughened zirconia abutments used for implant-supported restorations and to evaluate the effects of several clinical variables on these rates. Material and methods: From May 1998 to September 2010, 213 patients aged 18 years or older were recruited. The patients ...