以氟化蒙脫石做為牙醫用複合樹脂無機填料

Abstract

牙科複合樹脂綴補材料由於美觀性佳，在臨床使用上已經漸漸的取代汞齊合金.但是抗磨耗性仍然不甚理想，主因是複合樹脂中大多是採用熔融矽、硼矽酸玻璃及石英等作為無機填料，雖然能抑制基質的變形，提高機械強度，但由於此類的無機填料無法與樹脂基質形成化學鍵結，常因牙齒上下咀嚼食物，使突出的填料顆粒因機械力作用而造成破裂脫落（protruding）現象，使牙科複合樹脂綴補材料在應用上受到限制。 臨床上大多數的複合樹脂無法良好持續釋放氟素，氟素有助鞏固牙齒及有防蛀功效，補牙後敏感的情況亦少發生。本研究目的為改進無機填料與樹脂基質之作用力與氟素的吸收釋放能力。蒙脫石(Montmorillonite)為一種由許多矽酸鹽層所堆疊構成的黏土礦物，由於層間可被外來分子或離子插入(intercalation)，因此理論上可用來製備奈米複合材料。進行有機化處理可將單體或高分子導入層間，再於表面接枝適當構造之高分子，例如Bis-GMA，使無機塡料與高分子樹脂基材具有良好的作用力，增強牙科複合樹脂的機械強度。 本研究的主要方向是改進牙醫用複合樹脂中無機填料與樹脂基材的化學鍵結能力，提高磨耗強度使牙綴補材料更具實用性，並藉由氫氟酸(HF)處理蒙脫石，使蒙脫石表面矽酸鹽層形成含氟自由基，冺用氟化蒙脫石(Fluoride-Montmorillonite)及層間差層高分子吸附氟離子，讓牙綴補複合材料可再吸收、釋放氟素，於預防二次齲齒有良好的功用。實驗結果顯示在抗磨耗性方面與市售Estelite複合樹脂相當，而氟離子釋放與再填充的效果比含氟玻璃離子體GC Fuji II更好，經WST-1和LDH實驗證實我們的材料無細胞毒性。我們認為這種複合樹脂於牙綴補材料中可以發揮更好的功用。

The use of composite resin materials for posterior tooth restorations is increasing. This increase is attributed primarily to a demand for improved esthetics. However, poor material properties limited the success of composite restorations in posterior teeth. Microleakage, fractures within the body of the restorations, marginal ditching, protruding, and imperfect wear resistance are reported as being the most common causes of failure in posterior composites. Fluoride release from restorative materials may prevent development of secondary carious lesions at the restoration tooth interface and can develop remineralization of enamel or decalcified dentin, so long as physical and mechanical properties are not adversely affected. The object of this study was to investigate a new composite resin with good bonding between resin matrix and inorganic filler. Besides, It is desirable that restorative material is enough fluoride release for immediate and long-term caries protection. Montmorillonite is a layered aluminosilicate of the 2:1 type. Crystal structure consists of layers made up of two tetrahedrally coordinated silicon atoms fused to an edge-shared octahedral sheet of aluminum. The organofunctionalization of montmorillonite can be made after the intercalation of small polar molecules, such as N-methyl formamide (NMF). A montmorillonite/acrylamide intercalation compound was synthesized by guest displacement reaction of a montmorillonite/NMF intercalation compound. It is desirable that montmorillonite/acrylamide compound could graft on resin matrix and improve the composite resin mechanical properties and wear resistant. We use hydrofluoric acid via the fluorination method to improve the fluoride release and recharge ability of montmorillonite. We can prepare the anti-caries of fluoride-contaning dental restorative materials by hydrofluoric acid modified MMT intercalation compounds that contained fluoride.