Donly K J, Ruiz M
College of Dentistry, University of Iowa, Iowa City, IA 52242.
Clin Prev Dent. 1992 Nov-Dec;14(6):22-4.
Smooth surface caries remain a concern in children, particularly those that are diagnosed with "baby bottle caries." The purpose of this study was to evaluate the caries inhibition of an unfilled resin placed on smooth enamel surfaces. Incisors were obtained and painted with an acid-protective varnish, excluding 2 mm x 6 mm windows on the labial surface. Each tooth had an unfilled resin placed over half the area of the window; the remaining area was not treated. One hundred microns longitudinal sections were obtained from the treated and non-treated sites. Polarized photomicrographs were taken of each section, in imbibition media of air, water and Thoulet's (R.I.: 1.41, 1.47), representing a minimum of 1%, 5%, 10%, and 25% pore volume respectively. The sections were then painted with an acid-protective varnish so that only the external surface was exposed and placed in separate closed environments of a non-fluoridated artificial saliva. One section from each tooth had unfilled resin on the external surface, one section had only natural enamel exposed, and a third section had the external surface varnished to act as a control. The teeth were thermocycled at 10 degrees C and 50 degrees C, 20 cycles per day for three months; they were also cycled through artificial caries challenge (pH 4.4) for 35 minutes, three times per day. Sections were then photographed under polarized light, as before, and areas of lesions were digitized. Results demonstrated caries to be present on all non-treated enamel surfaces exposed to the artificial caries challenge. Significantly less enamel demineralization occurred when an unfilled resin was placed on it (p < 0.001).
光滑面龋仍然是儿童关注的问题，尤其是那些被诊断为“奶瓶龋”的儿童。本研究的目的是评估未填充树脂对光滑牙釉质表面的防龋作用。获取切牙并涂上防酸漆，唇面留出2mm×6mm的窗口。每颗牙齿在窗口一半的面积上放置未填充树脂，其余区域不做处理。从处理和未处理部位获取100微米的纵向切片。在空气、水和图莱液（折光率：1.41、1.47）的浸润介质中对每个切片拍摄偏光显微照片，分别代表至少1%、5%、10%和25%的孔隙体积。然后给切片涂上防酸漆，使仅外表面暴露，并放置在未加氟的人工唾液的单独封闭环境中。每颗牙齿的一个切片外表面有未填充树脂，一个切片仅暴露天然牙釉质，第三个切片外表面涂漆作为对照。将牙齿在10℃和50℃下进行热循环，每天20个循环，持续三个月；它们还每天三次通过人工龋挑战（pH 4.4）35分钟。然后像之前一样在偏光下拍摄切片，并对病变区域进行数字化处理。结果表明，所有暴露于人工龋挑战的未处理牙釉质表面均出现龋损。当在牙釉质上放置未填充树脂时，牙釉质脱矿明显减少（p<0.001）。
