Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi2O3/Ta2O5 Composite Powders Prepared by Mechanical Milling

Hsiu-Na Lin; Chung-Kwei Lin; Pei-Jung Chang; Wei-Min Chang; Alex Fang; Chin-Yi Chen; Chia-Chun Yu; Pee-Yew Lee

doi:10.3390/ma14237447

Effect of Tantalum Pentoxide Addition on the Radiopacity Performance of Bi₂O₃/Ta₂O₅ Composite Powders Prepared by Mechanical Milling

Materials (Basel). 2021 Dec 4;14(23):7447. doi: 10.3390/ma14237447.

Authors

Hsiu-Na Lin^{1

2}, Chung-Kwei Lin^{1

3}, Pei-Jung Chang^{1

4}, Wei-Min Chang^{1

5}, Alex Fang⁶, Chin-Yi Chen^{1

7}, Chia-Chun Yu^{1

8}, Pee-Yew Lee^{1

9}

Affiliations

¹ Research Center of Digital Oral Science and Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan.
² Department of Dentistry, Chang Gung Memorial Hospital, Taipei 110, Taiwan.
³ School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan.
⁴ Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 111, Taiwan.
⁵ School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan.
⁶ Department of Engineering Technology and Industrial Distribution, Texas A&M University, College Station, TX 77843, USA.
⁷ Department of Materials Science and Engineering, Feng Chia University, Taichung 407, Taiwan.
⁸ Center of Dental Technology, Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan.
⁹ Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 202, Taiwan.

Abstract

Among the various phases of bismuth oxide, the high temperature metastable face-centered cubic δ phase attracts great attention due to its unique properties. It can be used as an ionic conductor or an endodontic radiopacifying material. However, no reports concerning tantalum and bismuth binary oxide prepared by high energy ball milling and serving as a dental radiopacifier can be found. In the present study, Ta₂O₅-added Bi₂O₃ composite powders were mechanically milled to investigate the formation of these metastable phases. The as-milled powders were examined by X-ray diffraction and scanning electron microscopy to reveal the structural evolution. The as-milled composite powders then served as the radiopacifier within mineral trioxide aggregates (i.e., MTA). Radiopacity performance, diametral tensile strength, setting times, and biocompatibility of MTA-like cements solidified by deionized water, saline, or 10% calcium chloride solution were investigated. The experimental results showed that subsequent formation of high temperature metastable β-Bi_7.8Ta_0.2O_12.2, δ-Bi₂O₃, and δ-Bi₃TaO₇ phases can be observed after mechanical milling of (Bi₂O₃)₉₅(Ta₂O₅)₅ or (Bi₂O₃)₈₀(Ta₂O₅)₂₀ powder mixtures. Compared to its pristine Bi₂O₃ counterpart with a radiopacity of 4.42 mmAl, long setting times (60 and 120 min for initial and final setting times) and 84% MG-63 cell viability, MTA-like cement prepared from (Bi₂O₃)₉₅(Ta₂O₅)₅ powder exhibited superior performance with a radiopacity of 5.92 mmAl (the highest in the present work), accelerated setting times (the initial and final setting time can be shortened to 25 and 40 min, respectively), and biocompatibility (94% cell viability).

Keywords: biocompatibility; bismuth oxide; diametral tensile strength; high temperature metastable phase; mechanical milling; radiopacity; setting time; tantalum pentoxide.

Abstract

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