The purpose of this study was to determine the maximum permissible x-ray tube angulation that can be used to verify the fit of an abutment. An implant and an abutment were assembled with an abutment screw. A variety of openings were created between the abutment and the implant. Radiographs were taken combining the different gaps with various x-ray tube angulations. The radiographs were randomly...

PURPOSE Finite element study on the effect of abutment length and material on implant bone interface against dynamic loading. MATERIALS AND METHODS Two dimensional finite element models of cylinderical implant, abutments and bone made by titanium or polyoxymethylene were simulated with the aid of Marc/Mentat software. Each model represented bone, implant and titanium or polyoxymethylene abutm...

OBJECTIVES The purpose of this in vitro study was to evaluate misfit alterations at the implant/abutment interface of external and internal connection implant systems when subjected to cyclic loading. MATERIAL AND METHODS Standard metal crowns were fabricated for 5 groups (n=10) of implant/abutment assemblies: Group 1, external hexagon implant and UCLA cast-on premachined abutment; Group 2, i...

OBJECTIVES The purpose of this study was to determine the influence of platform switching on stress distribution of two different implant systems using three-dimensional (3D) finite element models. MATERIALS AND METHODS Six 3D finite element models were created to replicate two different implant systems with peri-implant bone tissue, in which six different implant-abutment configurations were...

The success rate of osseointegrated implants is reported to be above 90%. Despite of the knowledge of the mechanisms of osseointegration, some faults still occur at implants systems. Recent researches assign those faults mainly to patient’s prosthetic rehabilitation. The misfit at abutment-implant interface and the missing of a passive adaptation between the prosthesis and the abutment can lead...

Preload loss can favor the occurrence of implant-abutment interface misfit, and bacterial colonization at this interface may lead to implant failure. The aim of this study was to evaluate the preload loss and bacterial penetration through the implant-abutment interface of conical and external hexagon connection systems subjected to thermal cycling and mechanical fatigue (TM). Four different imp...

Maintenance of the integrity of the abutment/implant interface is essential and is dependent on the abutment screw retaining a preload. Evaluation of this joint is usually done by manual assessment. The purpose of the current study was to determine whether the Periotest instrument could be used to evaluate abutment screw loosening. A custom-designed apparatus was constructed to measure abutment...

To evaluate the sealing capability of external hexagon implant systems and assess the marginal fit, two groups (n = 10 each) were employed: SIN (Sistema de Implantes Nacional, Brazil) and Osseotite, (Biomet 3i, USA). Sealing capability was determined by placing 0.7 μL of 1% acid-red solution in the implant wells before the torque of their respective abutments. Specimens were then placed into 2....

A study of the implant to abutment connection is of paramount importance as it is the primary determinant of the strength and stability of the implant supported restoration, which in turn determines the restoration’s prosthetic stability. Traditionally, the Branemark's external hexagon has been widely used but its significant complications like abutment screw loosening, rotational misfit at imp...

BACKGROUND Accumulating evidence suggests that alveolar crestal bone resorption occurs as a result of the microgap that is present between the implant-abutment interface in dental implants. The objective of this longitudinal radiographic study was to determine whether the size of the interface or the microgap between the implant and abutment influences the amount of crestal bone loss in unloade...