Garcia M B, Carrilho M R, Nör J E, Anauate-Netto C, Anido-Anido A, Amore R, Tjäderhane L, Bretz W A
Department of Biochemistry, Universidade São Francisco, School of Dentistry and School of Pharmacy, Bragança Paulista, Brazil.
Caries Res. 2009;43(2):92-6. doi: 10.1159/000209340. Epub 2009 Mar 24.
The purpose of this study was to evaluate the effect of chlorhexidine on the proteolytic activity of carious coronal and root dentin collected from patients. Sound dentin from freshly extracted human teeth was used as a control. Dentin fragments were mixed with a synthetic substrate for proteolytic enzymes (N-benzoyl-DL-arginine-naphthylamide--BANA) and the suspensions mixed with either 0.12% chlorhexidine digluconate or distilled water. These mixtures were incubated for 18 h at 37 degrees C, color was developed by the addition of 0.1% Fast Garnet and their optical density was recorded spectrophotometrically. BANA hydrolysis measured by the optical density of incubated specimens was detected in all tested groups, but was significantly higher for carious than for sound dentin (p < 0.05). The proteolytic activity was reduced for carious coronal and root dentin by chlorhexidine (p < 0.05; 50 and 30%, respectively). Chlorhexidine also reduced the proteolytic activity in sound root dentin (p < 0.05; 20%). Conversely, changes in the proteolytic activity of sound coronal dentin were not observed in the presence of chlorhexidine. The reduction in proteolytic activity by chlorhexidine was significantly higher in carious coronal dentin than in carious root dentin (p < 0.05). In conclusion, part of the effect of chlorhexidine in controlling caries progression in humans may be due to a decrease in the proteolytic activity of carious coronal and root dentin. Because of the prolonged incubation time in the present study, similar results may be obtained clinically with prolonged dentin exposure to chlorhexidine, e.g. chlorhexidine-containing varnishes.
本研究的目的是评估洗必泰对从患者收集的龋损冠部和根部牙本质蛋白水解活性的影响。将新鲜拔除的人牙的健康牙本质用作对照。将牙本质碎片与蛋白水解酶的合成底物（N-苯甲酰-DL-精氨酸萘酰胺 - BANA）混合，然后将悬浮液与0.12%葡萄糖酸洗必泰或蒸馏水混合。这些混合物在37℃下孵育18小时，加入0.1%固红使其显色，并通过分光光度法记录其光密度。在所有测试组中均检测到通过孵育标本的光密度测量的BANA水解，但龋损牙本质中的水解明显高于健康牙本质（p < 0.05）。洗必泰使龋损冠部和根部牙本质的蛋白水解活性降低（p < 0.05；分别降低50%和30%）。洗必泰还降低了健康根部牙本质中的蛋白水解活性（p < 0.05；降低20%）。相反，在洗必泰存在的情况下，未观察到健康冠部牙本质蛋白水解活性的变化。洗必泰对龋损冠部牙本质蛋白水解活性的降低明显高于龋损根部牙本质（p < 0.05）。总之，洗必泰在控制人类龋齿进展中的部分作用可能是由于龋损冠部和根部牙本质蛋白水解活性的降低。由于本研究中的孵育时间较长，临床上牙本质长时间接触洗必泰（例如含洗必泰的清漆）可能会获得类似的结果。
