Flaitz C M, Hicks M J
Department of Stomatology, University of Texas-Houston Health Science Center, USA.
ASDC J Dent Child. 1996 Jul-Aug;63(4):249-56.
Whitening enamel with carbamide peroxide (CP) to remove cosmetically displeasing stains has become common-place in dental practice. This in vitro study evaluated CP treatment effects on enamel surface morphology and caries-like lesion susceptibility. Tooth quarters were prepared from 10 caries-free human molars following a fluoride-free prophylaxis. The tooth quarters were assigned to the following treatment groups: 1) Distobuccal-10 percent NW gel (Nite White, Discus Dental); 2) Distolingual-10 percent PL paste (Platinum, Colgate); 3) Mesiobuccal-16 percent NW gel; and 4) Mesiolingual-Control. Following the manufacturers' recommended treatment, each quarter was sectioned with one portion prepared for SEM and the other portion for caries-like lesion formation. Intact enamel surfaces were present with all treatments. Enamel prism markings with exaggerated prism peripheries and mild to moderate prism core loss were seen with both 10 percent NW and 16 percent NW gels, but was more prominent with 16 percent NW gel. Amorphous surface layers with occasional exposure of indistinct prism markings occurred with 10 percent PL paste. Body of lesion mean depths were 135 microns control, 159 microns 16 percent NW, 144 microns 10 percent NW, and 122 microns 10 percent PL. Lesion depths were significantly different (p < 0.05 DMR paired design) between 10 percent PL and 16 percent NW, and between control and 16 percent NW. Whitening enamel surfaces in vitro with 10 percent carbamide peroxide paste containing dicalcium phosphate dihydrate (Colgate-Platinum) produced an amorphous surface layer and reduced caries susceptibility when compared with 16 percent carbamide peroxide gel (Nite White).
使用过氧化脲（CP）美白牙釉质以去除在美观上令人不悦的色斑在牙科实践中已变得很常见。这项体外研究评估了CP治疗对牙釉质表面形态和类龋损易感性的影响。在进行无氟预防性处理后，从10颗无龋的人类磨牙制备牙半块。将牙半块分配到以下治疗组：1）远中颊侧 - 10% NW凝胶（Nite White，Discus Dental）；2）远中舌侧 - 10% PL糊剂（Platinum，高露洁）；3）近中颊侧 - 16% NW凝胶；4）近中舌侧 - 对照。按照制造商推荐的治疗方法进行处理后，将每个牙半块切片，一部分制备用于扫描电子显微镜（SEM）观察，另一部分用于形成类龋损。所有处理后牙釉质表面均完整。使用10% NW和16% NW凝胶时可见牙釉质棱柱标记，棱柱周边夸张且棱柱核心有轻度至中度损失，但16% NW凝胶更为明显。使用10% PL糊剂时出现无定形表面层，偶尔可见不清晰的棱柱标记。病变体平均深度在对照组为135微米，16% NW组为159微米，10% NW组为144微米，10% PL组为122微米。10% PL组和16% NW组之间以及对照组和16% NW组之间的病变深度存在显著差异（p < 0.05，DMR配对设计）。与16%过氧化脲凝胶（Nite White）相比，体外使用含二水磷酸二钙的10%过氧化脲糊剂（高露洁 - Platinum）美白牙釉质表面会产生无定形表面层并降低龋易感性。
