A Comparative Study on Microgap of Premade Abutments and Abutments Cast in Base Metal Alloys
The study compared the marginal accuracy of premade and cast abutments. Premade titanium, stainless steel, and gold abutments formed the control groups. Plastic abutments were cast in nickel-chromium, cobalt-chromium and grade IV titanium. The abutment/implant interface was analyzed. Analysis of variance and Duncan's multiple range test revealed no significant difference in mean marginal microgap between premade gold and titanium abutments and between premade stainless steel and cast titanium abutments. Statistically significant differences (P < .001) were found among all other groups.
Figure 1. Premade abutments for implant. (a) Premade standard abutments made of grade V titanium. (b) Premade standard abutments made of stainless steel. (c) Premachined standard gold abutments with plastic sleeve. Figure 2. Cast abutments. (a) Cast nickel-chromium abutments. (b) Cast cobalt-chromium abutments. (c) Cast grade IV titanium abutments.
(a) Scanned image of the interface between implant and premade titanium abutment. (b) Scanned image of the interface between implant and premade stainless-steel abutment. (c) Scanned image of the interface between implant and premachined standard gold abutments with plastic sleeve. (d) Scanned image of the interface between implant and cast Ni-Cr abutment. (e) Scanned image of the interface between implant and cast Co-Cr abutment. (f) Scanned image of the interface between implant and cast grade IV Titanium abutment.
Figure 4. Comparison of mean marginal microgap in micrometers for various milled and cast abutment groups. Figure 5. Schematic line diagrams of the specimens. (a) The internal hex implant and standard platform. The arrow points to the first reference bevel for measuring the vertical gap. (b) Premade titanium/ stainless steel abutment with arrow pointing to the second reference bevel for measuring the vertical gap. (c) Premachined standard gold abutment with arrow pointing to the second reference bevel for measuring the vertical gap. (d) Plastic abutment/cast abutment with arrow pointing to the second reference bevel for vertical gap measurement. Figure 6. (a) Process of approximation of implant and abutment. (b) Ideal approximation of the implant and abutment. Figure 7. (a) Bevels present on the standard platform and fitting surface of abutment contacts on their superior aspect. (b) Bevels present on the standard platform and fitting surface of the abutment contact on their inferior aspect; a gap exists on the superior aspect.
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