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Purpose: To investigate the clinical usefulness, a customized abutment produced with the Pd-Ag-In alloy was compared with a customized abutment produced with the conventional titanium alloy for discoloration and mechanical accuracy. Materials and Methods: Discoloration and resistance to corrosion of the Pd-Ag-In alloy were evaluated using chemical solutions. Marginal adaptation of internal-type implants and abutments was compared using 10 titanium abutments and 10 Pd-Ag-In abutments using a surface measuring system. A detorque test was performed on 12 implant-abutment complexes of each control and experimental group to investigate screw joint stability. Cyclic loading simulating a human's mastication movement for 1 year was applied after 30 Ncm initial tightening, and the removal torque was measured using a digital torque gauge. The noninferiority test was conducted to compare the Pd-Ag-In alloy with a titanium abutment with a 10% margin. Results: The Pd-Ag-In alloy had a warm yellow color and displayed stable resistance to discoloration and corrosion, resulting in an advantageous esthetic property. When compared to the titanium alloy, it did not show noninferiority with respect to the gap between the implant and the abutment; the gap was approximately 13.3 ym on average, which was not significantly different from those observed in previous studies. After long-term use, it displayed statistically significant noninferiority in the removal torque value compared to the titanium group. Conclusion: The Pd-Ag-In alloy-based customized abutment had good mechanical properties of the implant-abutment complex as well as a superior esthetic property, and can provide favorable outcomes in anterior implant restoration. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to measure and compare, using scanning electron microscopy, the abutment-implant interface of a Morse taper system before and after cyclic loading. Materials and Methods: Four Morse cone implants and four solid abutments were used. These abutments had been machined to reduce the diameter of the part corresponding to the site of prosthesis cementation. They were then screwed onto the implants and torqued to 25 N. Under a scanning electron microscope, 32 images (16 before and 16 after cycling) of the interfaces were obtained under ×1,000 and ×5,000 magnification. The samples were subjected to 345,600 cycles with a fatigue testing machine, in which the applied load was 80 N and the frequency was 4 Hz, to simulate chewing. With appropriate software (Image Tool 3.0), the marginal gaps of the interfaces before and after load cycling were measured. The data were analyzed with the Student t test at a significance level of 5%. Results: Significant differences were found between interfaces before and after cycling. Prior to mechanical cycling, the Morse taper implant/abutment assemblies exhibited an average gap size of 3.34 ± 2.17 μm, whereas the average gap size after mechanical cycling was 1.35 ± 0.64 μm. Conclusion: After mechanical cycling, there was a significant decrease in the size of the gap, which indicated better adaptation and sealing ability at the level of the microgap. [ABSTRACT FROM AUTHOR]

Vertical misfit of implant-abutment interface can affect the success of implant treatment; however, currently available modalities have limitations to detect these gaps. This study aimed to evaluate implant-abutment gaps in vitro using optical coherence tomography (OCT). Vertical misfit gaps sized 50,100,150, or 200 μm were created between external hexagonal implants and titanium abutments (Nobel Biocare, Göteborg, Sweden). A porcine gingival tissue slice, 0.5, 1.0, 1.5, or 2.0 mm in thickness, was placed on each implant-abutment interface. The gaps were evaluated by swept-source OCT at a center wavelength of 1330 nm (Panasonic Healthcare, Ehime, Japan) with beam angles of 90, 75 and 60 deg to the implant long-axis. The results suggested that while the measurements were precise, gap size and gingival thickness affected the sensitivity of detection. Gaps sized 100 μm and above could be detected with good accuracy under 0.5- or 1.0-mm-thick gingiva (GN). Around 70% of gaps sized 150 μm and above could be detected under 1.5-mm-thick GN. On the other hand, 80% of gaps under 2.0-mm-thick GN were not detected due to attenuation of near-infrared light through the soft tissue. OCT appeared as an effective tool for evaluating the misfit of implant-abutment under thin layers of soft tissu [ABSTRACT FROM AUTHOR]

Microorganisms from the oral cavity may settle at the implant-abutment interface (IAI). As a result, tissue inflammation could occur around these structures. The databases MEDLINE/PubMed and PubMed Central were used to identify articles published from 1981 through 2012 related to the microbial colonization in the implant-abutment gap and its consequence in terms of crest bone loss and osseointegration. The following considerations could be put forward, with respect to the clinical importance of IAI: (a) the space present at the IAI seems to allow bacterial leakage to occur, in spite of the size of this space; (b) bacterial leakage seems to occur at the IAI, irrespective of the type of connection. More studies are necessary to clarify the relationship between leakage at IAI and abutment connection designs; (c) losses at the peri-implant bone crests cannot be related to the IAI size, since few studies have shown no relationship. Also, the microbial leakage at the IAI cannot be related to the bone crest loss, since there are no articles reporting this relationship; remains controversial the influence of the IAI position on the bone crest losses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1321-1328, 2013. [ABSTRACT FROM AUTHOR]

This study sought to evaluate the sealing capability of the implant abutment connection of different dental implant systems. Five Nobel Replace select, Straumann and Intra-lock implants of approximately 4·5 mm diameter with their respective abutments were provided by the manufacturers. A calibration curve was determined by placing toluidine blue (TB) increments of 0·1 μL into 1·5 mL of distilled water and recording its absorbance in a spectrophotometer until reaching 0·7 μL. Then, 0·7 μL of TB was placed in the deepest portion of each implant’s internal screw, the abutments were adapted to the implant according to the manufacturer’s instructions and the specimens were placed in vials with 1·5 mL of distilled water. Spectrophotometric analysis was performed at 1, 3, 6, 24, 48, 72, 96 and 144 h. Statistical analysis was performed by One-wayanova at 95% level of significance. The calibration curve was linear with respect to the TB amount in 1·5 μL distilled water ( R2 = 0·9961). All implant abutment systems presented an increase in absorbance as a function of time. As time elapsed in vitro, significantly higher amounts of TB was released from the Straumann and Nobel Replace Select connection systems ( P < 0·0001). Leakage was significant between the groups. Despite controlled torquing, the seal between the implant body and the abutment could not be maintained in all three of the systems tested. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a technique to evaluate the implant–abutment gap of an external hexagon implant system as a function of radius. Six implants of 3·75 mm in diameter (Conexao Sistema de Protese Ltda, Sao Paulo, Brazil) and their respective abutments were screw connected and torqued to 20 N cm−1. The implants were mounted in epoxy assuring an implant long-axis position perpendicular to the vertical axis. Each implant was grounded through its thickness parallel to implant long-axis at six different distance interval. Implant–abutment gap distances were recorded along the implant–abutment region for each section. Individual measurements were related to their radial position through trigonometric inferences. A sixth degree polynomial line fit approach determined radial adaptation patterns for each implant. Micrographs along implant sections showed a approximately 300 μm length implant–abutment engagement region. All implants presented communication between external and internal regions through connection gaps and inaccurate implant–abutment alignment. Average gap distances were not significantly different between implants ( P > 0·086). Polynomial lines showed implant-abutment gap values below 10 μm from 0 μm to approximately 250 μm of the implant–abutment engagement region. Gap distances significantly increased from approximately 250 μm to the outer radius of the implant–abutment engagement region. The technique described provided a broader scenario of the implant–abutment gap adaptation compared with previous work concerning implant–abutment gap determination, and should be considered for better understanding mechanical aspects or biological effects of implant–abutment adaptation on peri-implant tissues. [ABSTRACT FROM AUTHOR]