含氟涂料对光固化复合树脂腐蚀作用的探讨

目的评估不同含氟涂料对5种光固化复合树脂表面的腐蚀作用。方法选取5种光固化复合树脂微填料复合树脂（Ar）、纳米混合复合树脂（Gr）、纳米复合树脂（Su）、复合体（GI）和聚硅氧烷复合树脂（Ad）]制成φP6mm×3mm试样各25个。表面磨平抛光后分别用4种含氟涂料（F、G、D、B）于37℃100％相对湿度下处理30min，单次蒸馏水作为对照。扫描电镜观察试样表面的形态改变，并行激光共聚焦显微镜分析。结果含氟涂料对4种复合树脂均产生腐蚀作用（Su除外），腐蚀程度由强到弱的顺序为F、G、D、B。试样腐蚀形式均为表面粗糙。含氟涂料F和G作用于Ad后其改变最明显。经激光共聚焦显微镜分析，含氟涂料处理后复合树脂表面参数数值均增大。Su表面参数改变不明显。结论含氟涂料对复合树脂有腐蚀作用，腐蚀程度与复合树脂的类型、含氟涂料的种类相关。

Corrosive effect of topical fluoride agents on surfaces of five composite resins

OBJECTIVE: To evaluate the potential corrosive effect of topical fluoride agents used for professional treatments at dental prophylaxis on the polished surfaces of five composite resins. METHODS: A total of 125 specimens were fabricated from microhybrid composite, nanocombined composite, nanocomposite, compomer and ormocer in a phi 6 mm x 3 mm cavity with 25 specimens for each composite group. The flat surfaces of the specimens were smoothed and polished, then applied respectively with four topical fluoride agents and distilled water, and stored at 37 degrees C 100% relative humidity for 30 min. The changes in morphologic features of the surfaces were assessed by scanning electron microscopy (SEM). The disintegrated surface was further analysed under a confocal laser scanning microscope (CLSM). RESULTS: All fluorides showed reaction to all composites except nanocomposite. The aggressiveness of the fluorides arranged sequentially as F (Elmex fluid) > G (Elmex gelée) > D (Duraphat) > B (Bifluorid 12). The treated surfaces were generally rough. F and G caused the overall surface corrosion, whereas etching on the surface by D and B was sporadic confined. The destructive effects demonstrated a large number of craters on the surface somewhat like an atoll owing to filler dissolution. Crack formation resulted in destruction of the filler-matrix interface was observed. Ormocer was severely affected after F and G treatment. Instead of crater glass filler protruding from the bumpy surface indicated the excessively disintegrated matrix of ormocer. Topography under CLSM exhibited the roughening of the composite surface, roughness parameters for profile (Sa, Sz, Smax) increased when the surface was treated. Surface change in nanocomposite specimens was neither visually nor numerically discerned. CONCLUSIONS: Topical application of highly concentrated fluoride prophylactic agents leaded to surface degradation and porosity of composite, nanocomposite was, however, chemically resistant. Isolation of the composite surface should be considered in clinical application of topical fluoride.