腔型规划对口腔陶瓷降解性的影响

编辑

在过去的四十年中，多种陶瓷系统在材料性能方面取得了相当大的进展。全瓷冠的存活率因所使用的陶瓷类型、制作方法和临床适应症而异。氧化锆和硅酸锂是当代牙科最常用的陶瓷材料。这些类型的修复的生存数据似乎很有希望;然而，缺乏关于这些修复成功的高质量的长期临床数据。在缺乏可靠的纵向临床研究的情况下，实验室研究为陶瓷修复体的性能提供了一些有用的信息。需要进一步高质量的长期临床研究来告诉我们这些修复的失败模式以及每种类型的陶瓷修复可能使用的临床情况的范围。牙科陶瓷的降解一般是由于机械力或化学作用而发生的。陶瓷在生理上可能产生的副作用有:它们倾向于磨损相对的牙齿结构，放射性成分放射出辐射，因化学作用而使其表面变得粗糙，相应的斑块滞留增加，以及由于磨损和溶解而释放出潜在的不安全浓度的元素。牙科陶瓷的化学耐久性很好。 With the exception of the excessive exposure to acidulated fluoride, ammonium fluoride, or hydrofluoric acid, there is little risk of surface degradation of virtually all current dental ceramics. Extensive exposure to acidulated fluoride is a possible problem for individuals with head and/or neck cancer who have received large doses of radiation. Such fluoride treatment is necessary to minimize tooth demineralization when saliva flow rates have been reduced because of radiation exposure to salivary glands. Porcelain surface stains are also lost occasionally when abraded by prophylaxis pastes and/or acidulated fluoride. In each case, the solutes are usually not ingested. Further research that uses standardized testing procedures is needed on the chemical durability of dental ceramics. Accelerated durability tests are desirable to minimize the time required for such measurements. The influence of chemical durability on surface roughness and the subsequent effect of roughness on wear of the ceramic restorations as well as of opposing structures should also be explored on a standardized basis. Thermo luminescence (TL) emission of dental ceramics could be potentially used for retrospective dosimeter purposes as this allows a quick and reliable dose assessment in case of nuclear accident or bad use of a nuclear attack. This paper reports on the chemical and luminescence characterization of glass, Feld spathic and lithium dislocate glass ceramic (LS₂)．瑞典和土耳其牙科陶瓷由Divalent Ivoclar提供，考虑到:(我)的剂量反应范围10 Gy 6.9 kGy的显示一个线性剂量效应在低剂量值高达36 Gy(玻璃和菲尔德多晶石的陶瓷)和显示子线性行为从12 Gy 6 kGy的(锂打乱玻璃陶瓷),(2)一个TL信号的再现性发光曲线下的面积增加约25%,此前10周期玻璃和锂二矽酸盐陶瓷和增加约30%,此前七个周期为菲尔德多晶石的陶瓷,(iii)发光发射随时间变化的稳定性以及(iv)加热速率的影响。玻璃、硅酸锂和菲尔德硅酸陶瓷显示出复杂的uv -蓝色发光发射，可以分别适用于五组和四组假设一级动力学行为的组分。整体式氧化锆修复是修复性牙科的一种可接受的治疗方法，也是美容牙科的发展趋势。数字牙科简化了整体式氧化锆修复体的制作。氧化锆陶瓷为修复提供了实现美学和机械要求的机会。这在牙科陶瓷中很少见。整体氧化锆修复体代表了可接受的耐久性，与金属-陶瓷修复体相当，而它们在美学上优于金属-陶瓷修复体; however, difficulties to gain an optimal shade reproduction and a colour match with monolithic zirconia restorations still remain. The colour of these restorations may be influenced by manufacturing processes, laboratory procedures, and clinical factors. Manufacturing processes determine basic optical properties of zirconia ceramics. Different laboratory procedures may create optical changes in zirconia ceramics. Also clinical factors such as dental background, cement, and zirconia restoration features may affect the resulting color. This literature review aimed to discuss potent factors in the colour of monolithic zirconia restorations. An electronic search of the PubMed/Google Scholar database was performed to key terms of background, cement, ceramic; colour, aesthetics, shade, spectrophotometry, thickness, translucency, and zirconia were used both individually and simultaneously. Also, a manual search was conducted, and five classic articles of colour science were added. Thus 192 articles were included. In the last decade, shade reproduction of monolithic zirconia restorations has been highly regarded; however, further improvements are required in the manufacturing process to produce tooth-like zirconia ceramics. An aesthetic guideline named background-cement-ceramic colour harmony was suggested in this study; however, more clinical practice guidelines should be established for monolithic zirconia restorations on aesthetics, and therefore, more studies are required.