Takahashi H, Okamoto Y, Fujinaka S, Shintani H
Department of Operative Dentistry, Hiroshima University School of Dentistry, Japan.
J Prosthet Dent. 1993 Sep;70(3):261-3. doi: 10.1016/0022-3913(93)90062-s.
This study examined the effects of tannic acid on smear layer removal. Class V cavities were prepared on the buccal surfaces of extracted human molars with a No. 1557 high-speed carbide bur under water cooling for cutting and a No. 701 low-speed steel bur for finishing. They were then washed with water followed by an application of 2%, 5%, 10%, 15%, 20%, or 25% tannic acid solution in water for 15, 30, or 60 seconds. The axial wall dentin surfaces were examined with scanning electron microscopy. This examination showed that an application of 2% tannic acid for 60 seconds or 5% tannic acid for 15, 30, or 60 seconds effectively removed the smear layer, leaving the dentinal tubules occluded. The dentinal surfaces treated with 40% phosphoric acid for 15 seconds showed many exposed dentinal tubules with flared orifices.
