Characteristics of implant-CAD/CAM abutment connections of two different internal connection systems.

Titanium or zirconium computer-aided design/computer-aided manufacturing abutments are now widely used for aesthetic implant treatments; however, information regarding microscopic structural differences that may influence the biological and mechanical outcomes of different implant systems is limited. Therefore, the characteristics of different connection systems were investigated. Optical microscopic observation and scanning electron microscopy showed different characteristics of two internal systems, namely the Astra Tech and the Replace Select system, and for different materials. The scanning electron microscopic observation showed for the Astra Tech that the implant-abutment interface seemed to be completely sealed for both titanium and zirconium abutments, both horizontally and sagittally; however, the first implant-abutment contact was below the fixture top, creating a microgap, and fixtures connected with titanium abutments showed significantly larger values (23·56μm±5·44 in width, and 168·78μm±30·39 in depth, P<0·001). For Replace Select, scanning electron microscopy in the sagittal direction showed that the sealing of titanium and zirconium abutments differed. The seal between the implant-titanium and implant-zirconium abutments seemed to be complete at the butt-joint interface; however, the displacement of the abutment in relation to the fixture in the lateral direction was evident for both abutments with no statistical differences (P>0·70), creating an inverted microgap. Thus, microscopy evaluation of two commonly used internal systems connected to titanium or zirconium abutments showed that the implant-abutment interface was perfectly sealed under no-loading conditions. However, an inverted microgap was seen in both systems, which may result in bacterial accumulation as well as alteration of stress distribution at the implant-abutment interface.

[1]  F. Brunella,et al.  Internal contamination of a 2-component implant system after occlusal loading and provisionally luted reconstruction with or without a washer device. , 2001, Journal of periodontology.

[2]  W R Krause,et al.  FINITE ELEMENT ANALYSIS OF INTERFACE GEOMETRY EFFECTS ON THE CRESTAL BONE SURROUNDING A DENTAL IMPLANT , 1992, Implant dentistry.

[3]  J. Hobkirk,et al.  The effects of superstructure fit and loading on individual implant units: Part 2. The effects of loading a superstructure with varying degrees of fit. , 1996, The European journal of prosthodontics and restorative dentistry.

[4]  T Jemt,et al.  3-year followup study of early single implant restorations ad modum Brånemark. , 1990, The International journal of periodontics & restorative dentistry.

[5]  R. Palmer,et al.  A prospective study of Astra single tooth implants. , 1997, Clinical oral implants research.

[6]  E. Watanabe,et al.  In vitro evaluation of bacterial leakage along the implant-abutment interface of an external-hex implant after saliva incubation. , 2011, The International journal of oral & maxillofacial implants.

[7]  P P Binon,et al.  The effect of eliminating implant/abutment rotational misfit on screw joint stability. , 1996, The International journal of prosthodontics.

[8]  M Sogo,et al.  In vitro differences of stress concentrations for internal and external hex implant-abutment connections: a short communication. , 2006, Journal of oral rehabilitation.

[9]  K. Akca,et al.  Biomechanical Aspects of Bone-Level Diameter Shifting at Implant-Abutment Interface , 2009, Implant dentistry.

[10]  P G Coelho,et al.  In vitro evaluation of the implant abutment connection sealing capability of different implant systems. , 2008, Journal of oral rehabilitation.

[11]  D van Steenberghe,et al.  A study of 589 consecutive implants supporting complete fixed prostheses. Part II: Prosthetic aspects. , 1992, The Journal of prosthetic dentistry.

[12]  L. McManus,et al.  Peri-implant Inflammation Defined by the Implant-Abutment Interface , 2006, Journal of dental research.

[13]  A. Wennerberg,et al.  Topography, microhardness, and precision of fit on ready-made zirconia abutment before/after sintering process. , 2007, Clinical implant dentistry and related research.

[14]  S. Wallet,et al.  Bacterial colonization of the dental implant fixture-abutment interface: an in vitro study. , 2009, Journal of periodontology.

[15]  Heoung-Jae Chun,et al.  Influence of implant abutment type on stress distribution in bone under various loading conditions using finite element analysis. , 2006, The International journal of oral & maxillofacial implants.

[16]  George Priest,et al.  Virtual-designed and computer-milled implant abutments. , 2005, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[17]  P P Binon,et al.  The effect of implant/abutment hexagonal misfit on screw joint stability. , 1996, The International journal of prosthodontics.

[18]  R B Kerstein,et al.  Ideal gingival form with computer-generated permanent healing abutments. , 2000, Compendium of continuing education in dentistry.

[19]  S Toreskog,et al.  A 5-year multicenter study on implant-supported single crown restorations. , 1998, The International journal of oral & maxillofacial implants.

[20]  P. Coelho,et al.  Sealing Capability and SEM Observation of the Implant-Abutment Interface , 2011, International journal of dentistry.

[21]  Wenhe Liao,et al.  Design of a custom angled abutment for dental implants using computer-aided design and nonlinear finite element analysis. , 2010, Journal of biomechanics.

[22]  T Jemt,et al.  Three-dimensional distortion of gold alloy castings and welded titanium frameworks. Measurements of the precision of fit between completed implant prostheses and the master casts in routine edentulous situations. , 1995, Journal of oral rehabilitation.

[23]  M. Welander,et al.  Subcrestal placement of two-part implants. , 2009, Clinical oral implants research.

[24]  R. Puers,et al.  Implant design and interface force transfer , 2004 .

[25]  P G Coelho,et al.  Cross-sectional analysis of the implant-abutment interface. , 2007, Journal of oral rehabilitation.

[26]  Hom-lay Wang,et al.  Socket morphology-based treatment for implant esthetics: a pilot study. , 2010, The International journal of oral & maxillofacial implants.

[27]  D Buser,et al.  Persistent Acute Inflammation at the Implant-Abutment Interface , 2003, Journal of dental research.

[28]  T. Taylor,et al.  Loading of bone surrounding implants through three-unit fixed partial denture fixation: a finite-element analysis based on in vitro and in vivo strain measurements. , 2006, Clinical oral implants research.

[29]  Shuichi Nomura,et al.  Biomechanical aspects of marginal bone resorption around osseointegrated implants: considerations based on a three-dimensional finite element analysis. , 2004, Clinical oral implants research.

[30]  M. Nagata,et al.  Influence of microgap location and configuration on peri-implant bone morphology in nonsubmerged implants: an experimental study in dogs. , 2010, The International journal of oral & maxillofacial implants.

[31]  N D Millington,et al.  Inaccurate fit of implant superstructures. Part 1: Stresses generated on the superstructure relative to the size of fit discrepancy. , 1995, The International journal of prosthodontics.

[32]  C. Goodacre,et al.  Flapless anterior implant surgery: a surgical and prosthodontic rationale. , 2000, Practical periodontics and aesthetic dentistry : PPAD.

[33]  A. A. Del Bel Cury,et al.  Preload loss and bacterial penetration on different implant-abutment connection systems. , 2010, Brazilian dental journal.