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Measuring the Complete-arch Distortion of an Optical Dental Impression
Published on: May 30, 2019
Scanning electron microscope evaluation of vertical and horizontal discrepancy in cast copings for single-tooth
Hakimeh Siadat1, Marzieh Alikhasi, Ali Mirfazaelian
1Department of Prosthodontics and Implant, Department of Dental Research, School of Dentistry, Medical Sciences/University of Tehran, Tehran, Iran.
Implant Dentistry
|September 12, 2008
Summary
This study found no significant differences in vertical discrepancies among three implant framework casting techniques. However, using impression caps increased horizontal discrepancies, impacting implant fit and potentially leading to complications.
Area of Science:
- Dental materials science
- Prosthodontics
- Biomaterials engineering
Background:
- Marginal discrepancies in dental implant frameworks are common despite meticulous fabrication processes.
- These discrepancies can lead to crestal bone resorption, peri-implantitis, and loss of osseointegration, compromising implant success.
Purpose of the Study:
- To compare the marginal gap and overhang of three distinct casting techniques for fabricating implant frameworks.
- To evaluate the accuracy of implant framework fabrication using Burn-out Cap, Impression Cap, and conventional wax-up techniques.
Main Methods:
- Fabrication of 24 implant frameworks using Burn-out Cap (BC), Impression Cap (IC), and conventional wax-up (WX) techniques (n=8 each).
- Casting with Type IV gold alloy, fixation on analog abutments, sectioning, and scanning electron microscopy (SEM) analysis at x200 magnification.
- Statistical analysis using multivariate analysis and post hoc tests (alpha = 0.05) to assess vertical and horizontal discrepancies.
Main Results:
- Mean vertical discrepancies were 53.74 ± 11.0 µm (BC), 63.6 ± 13.2 µm (IC), and 50.1 ± 17.3 µm (WX), with no statistically significant differences between groups (P > 0.05).
- The Impression Cap (IC) technique significantly increased horizontal discrepancies at the interfaces compared to other methods (P < 0.001).
Conclusions:
- All three casting techniques exhibited comparable vertical discrepancies, indicating similar levels of accuracy in this dimension.
- Conventional waxing resulted in the least horizontal discrepancy, though not statistically different from the Burn-out Cap technique. The Impression Cap technique showed a notable increase in horizontal discrepancies.
