Wear of Morse taper and external hexagon implant joints after abutment removal

Abstract

The aim of this in vitro study was to evaluate the removal torque values on abutments and the morphological wear aspects of two different dental implant joints after immersion in a medium containing biofilm from human saliva. Twenty implant-abutment assemblies were divided into four groups in this study: (A) Morse taper free of medium containing biofilm, and (B) after contact with a medium containing biofilm from human saliva; (C) External Hexagon free of medium containing biofilm, and (D) after contact with medium containing biofilm from human saliva. The abutments were firstly torqued to the implants according to the manufacturer´s recommendations, using a handheld torque meter. Groups B and D were immersed into 24 well-plates containing 2 ml BHI medium with microorganisms for 72 h at 37 °C under microaerophilic conditions. After detorque evaluation, the abutments were removed and the implants were analyzed by scanning electron microscopy (SEM) and profilometry. On the detorque evaluation, the torque values decreased for the external hexagon implants and increased for the Morse taper implants. However, the values were lower when both implant-abutment assemblies were in contact with a medium containing biofilm from human saliva. The wear areas of contacting surfaces of the implants were identified by SEM. The highest average roughness values were recorded on the surfaces free of biofilm. The medium containing biofilm from human saliva affected the maintenance of the torque values on Morse taper and external hexagon abutments. Additionally, the removal of abutment altered the inner implant surfaces resulting in an increase of wear of the titanium-based connection.

Sealing agent reduces formation of single and dual-species biofilms of Candida albicans and Enterococcus faecalis on screw joints at the abutment/implant interface

“…This result contradicts previous studies that have demonstrated the effectiveness of this connection in the containment of the microbial infiltration to its interface. [14, 30, 34]…”

Remnant oral biofilm and microorganisms after autoclaving sterilization of retrieved healing abutments

“…The high density of biofilm biomass could protect bacteria or spores located at retentive micro‐regions of the abutments leading to a potential re‐growth in nutrient‐rich medium such as found in the oral cavity. Retentive micro‐regions are inherent on healing abutments as a result of the machining process, surface treatment, and desiging 33,34 . Defects found on abutments and implant joint surfaces can promote a misfit between the implant and abutment connection 10,18,33,34 .…”

“…Retentive micro‐regions are inherent on healing abutments as a result of the machining process, surface treatment, and desiging 33,34 . Defects found on abutments and implant joint surfaces can promote a misfit between the implant and abutment connection 10,18,33,34 . As a consequence of the implant‐abutment misfit, the size of microgaps between abutment and implant can vary from 0.1 up to 15 μm 10,18,33 .…”

The features of interaction between dental implants and organism tissues and the modern methods of creation of antibacterial covering on implant surfaces

“…В организме происходит постепенное разруше ние, изнашивание всех инородных тел, даже кон струкций из очень прочных искусственных матери алов при контакте с биологическими тканями и жидкостями [2, 3], в том числе и имплантатов, из готовленных на основе титана [4,5,14,15].…”