The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

A pilot study on the fitness of a titanium root coping fabricated by CAM
system—Application of a high-precision scanner
Mineyo. SONE, Daikei MATSUMOTO, Yuki TANIUCHI, Kenji AOKI, Mie NUMAZAWA，Fumiko
NARUMI, Natsumi KOYAMA and Kazuhiko OKAMOTO
Division of Removable Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai
University School of Dentistry

Abstract
In this study, we report on the accuracy of matching titanium root copings fabricated using a highprecision laboratory scanner.
The abutment tooth was a preformed epoxy artificial tooth (A50-359, NISSIN). The manufacturing
procedure involves scanning a work model using a laboratory scanner (E3, 3Shape), modeling it using
design software (Dental System, 3Shape), and then cutting it with a milling machine (GeoMill ARUM
5X, GeoMedi). Five specimens were tested, and the fitting accuracy of the titanium root coping wasevaluated using the cement replica method.
The measurement points are the labial margin at point a, the labial cervix at point b, the labial post atpoint c, the tip of the post at point d, the lingual post at point e, the lingual cervix at point f, and thelingual margin at point g. The average gaps were 46.4±17.8 μm at point a, 59.6±13.6 μm at point b,31.6±8.9 μm at point c, 145.7±43.8 μm at point d, 46.4±11.2 μm at point e, 92.7±14.3 μm at point f, and
72.1±37.0 μm at point g.
It was suggested that the titanium root coping manufactured using a high-precision laboratory scanner
could be applied clinically.

Introduction
Recent advances in dental CAD/CAM systems have been remarkable, and they are expected to simplify
the workflow and improve the fitness of prostheses. At the 32nd Annual Meeting, we examined theaccuracy of the fitness of zirconia root copings made by scanning with a technical scanner alone. In thisstudy, we examined the accuracy of the conformity of the root coping fabricated using a titanium disk as
a new material for digitalization.

Materials and Methods
The abutment was an epoxy artificial tooth (A50-359, NISSIN) with a post part 5 ㎜ deep, as
recommended by JSMAD. As for the manufacturing procedure, after taking an impression according tothe standard method, a working model was made, it was scanned using a dental scanner for laboratoryuse (E3, 3Shape), and it was then scanned using design software (Dental System, 3Shape). Aftermodeling, we cut out titanium disk(DentalBank) using a milling machine(GeoMill ARUM 5X，GeoMedi) (Figs. 1 and 2). The cement space was the specified value of the software, and there were fivetest samples (Fig. 3).

[Web Presentation] PS4-1-1

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Fig. 1 Impression and working modelFig. 2 Scanned model and designed root coping

Fig. 3 Fabricated titanium root coping
The fitting accuracy was evaluated using the cement replica method, which quantifies the gap between
the model and the root coping based on the thickness of the silicone rubber coating (Fig. 4).

Fig. 4 Fabrication procedure of specimens (Cement-replica technique)[Web Presentation] PS4-1-2

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

In addition, the gap distance was measured by capturing a digital image of the cut surface of thesilicone rubber together with a scale used as a reference and measuring it on a PC. In addition, sevenmeasurement points were set as shown in Fig. 5.

Fig. 5 Measuring points(a:labial margin b:labial cervical c:labial center of post d: tip of the post
e: lingual center of post f: lingual cervical g: lingual margin)

Results
The average gaps were 46.4±17.8 μm at point a, 59.6±13.6 μm at point b, 31.6±8.9 μm at point c,145.7±43.8 μm at point d, 46.4±11.2 μm at point e, 92.7±14.3 μm at point f, and 72.1±37.0 μm at point g(Fig. 6). Measurement points a, b, c, e, f, and g showed good compatibility as compared with theallowable range of compatibility for CAD/CAM prostheses reported by Suto et al.,1⁾ which is 100 μm.
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Fig. 6 Average gap volume[Web Presentation] PS4-1-3fg

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Conclusion
This study suggested that the titanium root coping made by the technical scanner alone has a clinicallyapplicable conformance accuracy.
In the future, we will verify the conformance accuracy with a post length of 5 mm or more. We will also
consider whether it is possible to set the rotation prevention groove and the keeper housing part andcompare their compatibility with the zirconia root coping.

References
1.

N. Suto, S. Miura, R. Inagaki, Y. Kaneta, M. Yoda and K. Kimura: A Basic Study on Fitness of Allceramic Crown Fabricated by CAD/CAM System, Ann Jpn Prosthodont Soc, 1, 21–28, 2009.

[Web Presentation] PS4-1-4