漂白歯におけるパルスオキシメーターのSpO2測定値に対するエナメル質および象牙質厚の影響

The objective of this study was to analyze the influence of different enamel and dentin thicknesses on oxygen saturation (SpO₂) readings after dental bleaching. A total of 26 extracted human anterior teeth, sound and without defects, were used. The crown thickness was measured at the middle third using a thickness gauge. Color was evaluated with a spectrophotometer, and SpO₂ readings were obtained through a pulse oximeter coupled to an optical digital simulator, under two perfusion conditions: high (98% SpO₂, 75 bpm) and low (86% SpO₂, 75 bpm). The first reading was performed without the interposition of the dental element, serving as a positive control (L0). After recording SpO₂ and color readings through sound crowns (L1 and C1), the palatal or lingual surfaces were reduced to a thickness of 5 mm (L2), and a new color measurement was performed (C2). The samples were then subjected to dental bleaching, followed by additional color and SpO₂ readings (L3 and C3). Subsequently, the thickness was further reduced to 3 mm, and the measurements were repeated (L4 and C4). Color was evaluated descriptively. Significant differences (p < 0.001) were found between sound teeth (L1) and bleached teeth with 5 mm (L3) and 3 mm (L4) thickness, as well as between unbleached teeth with 5 mm (L2) and the bleached samples (L3 and L4). The findings of this study demonstrated higher SpO₂ readings by the pulse oximeter in bleached teeth. Bleaching had a greater impact on SpO₂ readings than dental thickness, regardless of perfusion condition.