Clinic for Conservative Dentistry and Periodontology, School for Dental Medicine, Christian-Albrechts-Universität zu Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany.
J Dent. 2010 Jan;38(1):65-71. doi: 10.1016/j.jdent.2009.09.001.
As a conditioning step for resin infiltration into caries lesions, the relatively impermeable surface layer should be removed using hydrochloric acid gel (15%) to achieve improved infiltration, as it could be shown for permanent teeth. It is unclear whether this etching regimen can be transferred to the deciduous dentition, where differences in surface structure have been reported. Thus, the aim of the present study was to evaluate the effect of phosphoric and hydrochloric acid gels on the surface layer reduction of natural lesions of primary teeth.
Thirty-two extracted or exfoliated primary molars with lesions confined to enamel were selected. Paired lesion halves were partially etched with either 37% phosphoric (H(3)PO(4)) or 15% hydrochloric acid gel (HCl) for 30s, 60s, 90s, or 120s, respectively.
Etching with H(3)PO(4) resulted in incomplete reduction of the surface layers in all groups [highest percentage reduction (SD) at 120s: 54 (28)%] as observed with confocal microscopy. In contrast, surface layers could be eroded almost completely [99 (3)%] by etching with HCl for 120s.
An effective erosion of the surface layer of natural enamel caries in deciduous teeth can be achieved by etching with 15% hydrochloric acid gel for 90-120s.
为了使树脂能够渗透到龋损部位，相对不可渗透的表层应该用盐酸凝胶（15%）去除，这在恒牙中已经得到了验证，可以提高渗透效果。但目前尚不清楚这种蚀刻方案是否可以应用于乳牙，因为已有报道称乳牙的表面结构存在差异。因此，本研究旨在评估磷酸和盐酸凝胶对乳牙自然龋损表面层减少的影响。
选择 32 颗具有局限于釉质病变的离体或自然脱落的乳牙。将成对的病变牙釉质的一半分别用 37%磷酸（H3PO4）或 15%盐酸凝胶（HCl）进行部分蚀刻，时间分别为 30s、60s、90s 和 120s。
共聚焦显微镜观察发现，H3PO4 处理的所有组中，表面层的去除都不完全[120s 时最大百分比减少（SD）：54（28）%]。相比之下，用 HCl 处理 120s 几乎可以完全侵蚀表面层[99（3）%]。
用 15%盐酸凝胶蚀刻 90-120s 可以有效去除乳牙自然釉质龋的表面层。
