Effects of fluoride releasing cement on the selective removal of cervical carious dentin

采用空气抛光装置，在压力下喷出碳酸氢钠研磨粉和水，用于去除龋齿牙本质。本研究采用硬度-深度曲线与中度牙本质龋软化模式相似的人工类龋病变作为实验材料。通过调节抛光装置的磨料条件选择性去除软化牙本质是可行的。氟化物释放水泥HY-BOND TEMPORARY cement R （Shofu）应用于使用抛光装置（Airbrasion Group）或挖掘机（digging Group）去除表层后剩余的软化牙本质。磨蚀组软化牙本质硬度明显高于开挖组。磨蚀组结果表明，再矿化牙本质对脱矿攻击有较强的抵抗能力。测定了磨蚀组与开挖组牙本质的抗拉结合强度。采用LITE-FIL II A （Shofu）作为复合树脂和FUJI IONOMER TYPE II LC作为玻璃离子水结剂两种修复材料。LITE-FIL II A与粘接树脂IMPERVA FLUORO BOND R （Shofu）结合。FUJI JONOMER TYPE II LC的平均粘结强度在磨损组为6.5MPa(*1.1)，在开挖组为4.9MPa（*1.5）。两组比较差异有统计学意义（p< 0.05）。综上所述，空气抛光装置在选择性去除颈龋牙本质及修复治疗中具有一定的应用价值。

A dental air polishing unit that jets abrading powder of sodium bicarbonate and water under pessure was applied to removal of cervical carious dentin. Artficical caries-like lesions whose hardness-depth curve showed similarity to the softened pattern of the moderate dentin caries were used in this study as experimental materials. The selective removal of softened dentin by regulating abrasive conditions of the polishing unit was practicable.Fluoide releasing cement, HY-BOND TEMPORARY CEMENT R (Shofu) was applied to the softened dentin remaing after the removal of superficical layers using the polishing unit (Airbrasion Group) or a excavator (Excavation Group). More increase in hardness of softened dentin was showed in Airbrasion Group than Excavation Group. Abrasion Group showed that the remineralized dentin was refractory to the demineralization attack.The tensile bond strengths to the dentin were tested and compared Abrasion Group with Excavation Group. Two kinds of restorative materials, LITE-FIL II A (Shofu) as a composae resin and FUJI IONOMER TYPE II LC as a glass ionomer cement were used. LITE-FIL II A was combined with the bonding resin, IMPERVA FLUORO BOND R (Shofu). The avarage bond strength for FUJI JONOMER TYPE II LC was 6.5MPa(*1.1) in Abrasion Group and was 4.9MPa(*1.5) in Excavation Group. There was a significant difference between the two groups (p<O.05).In conclusion, it was suggested that the application of the air polishing unit was valuable to selective removal of cervical carious dentin and restorative treatment.