Antony Katja, Genser Dieter, Hiebinger Cora, Windisch Friederike
Gesundheit Österreich GmbH, Geschäftsbereich ÖBIG, Wien, Österreich.
GMS Health Technol Assess. 2008 Nov 13;4:Doc12.
Caries is one of the most prevalent diseases worldwide. For (direct) restaurations of carious lesions, tooth-coloured composite materials are increasingly used. The compulsory health insurance pays for composite fillings in front teeth; in posterior teeth, patients have to bear the extra cost.
Amalgam is an alloy of mercury and other metals and has been used in dentistry for more than one hundred and fifty years. Composites consist of a resin matrix and chemically bonded fillers. They have been used for about fifty years in front teeth. Amalgam has a long longevity; the further development of composites has also shown improvements regarding their longevity.
This HTA-report aims to evaluate the longevity (failure rate, median survival time (MST), median age) of direct amalgam fillings in comparison to direct composite fillings in permanent teeth from a medical and economical perspective and discusses the ethical, legal and social aspects of using these filling materials.
The systematic literature search yielded a total of 1,149 abstracts. After a two-step selection process based on defined criteria 25 publications remained to be assessed.
The medical studies report a longer longevity for amalgam fillings than for composite fillings. However, the results of these studies show a large heterogeneity. No publication on the costs or the cost-effectiveness of amalgam and composite fillings exists for Germany. The economic analyses (NL, SWE, GB) report higher costs for composite fillings when longevity is assumed equal (for an observation period of five years) or longer for amalgam compared to composite fillings. These higher costs are due to the higher complexity of placing composite fillings.
Due to different study designs and insufficient documentation of study details, a comparison of different studies on longevity of direct amalgam and composite fillings in posterior teeth is difficult. Apart from the difficulties in conducting a randomized, controlled long-term study comparing the longevity of direct fillings, the fact that composites and adhesives used in a study have often already been replaced by the next generation of the product at the time of study publication presents an additional problem. Not only the filling material, but also patient parameters and local, intraoral factors (e. g. localisation of the filling) as well as the treating dentist have an impact on the longevity of dental fillings. In evaluating economic studies, one has to refer to the heterogeneity of data on longevity in the medical evaluation. The only effect parameter used in the studies is longevity, other aspects (e. g. long-term functionality) are only referred to in discussions. Extensive counselling of patients regarding the selection of the appropriate filling material is important.
Amalgam fillings show a longer longevity than composite fillings. Two out of six systematic reviews conclude that the expected survival time of composite fillings can be comparable to amalgam fillings. However, these conclusions are based on the results of short-term studies which usually overestimate the longevity of filling materials. From an economic standpoint, amalgam is the more economic filling material compared to direct composite fillings in posterior teeth when considering longevity as the only result parameter. Other aspects than longevity need to be considered in individually choosing the appropriate dental filling material. For future studies aiming to compare the longevity of amalgam and composite fillings, a sufficient sample size and study period, preferably in the setting of a private dental practice, should be aimed for. An evaluation of the cost-effectiveness of amalgam and composite fillings should take the functionality of teeth over a longer time period into account, as well as patients' preferences. The rapid development of composite materials and adhesives make short term revisions of these conclusions necessary.
龋齿是全球最普遍的疾病之一。对于龋损的（直接）修复，越来越多地使用牙齿颜色的复合材料。法定医疗保险支付前牙的复合填充物费用；而后牙的患者则需承担额外费用。
汞合金是汞与其他金属的合金，已在牙科领域使用了一百五十多年。复合材料由树脂基质和化学键合的填料组成。它们在前牙中使用了约五十年。汞合金使用寿命长；复合材料的进一步发展也显示出其使用寿命有所改善。
本卫生技术评估报告旨在从医学和经济角度评估恒牙中直接汞合金填充物与直接复合填充物的使用寿命（失败率、中位生存时间（MST）、中位年龄），并讨论使用这些填充材料的伦理、法律和社会方面。
系统文献检索共获得1149篇摘要。经过基于既定标准的两步筛选过程，剩下25篇出版物有待评估。
医学研究报告称汞合金填充物的使用寿命比复合填充物长。然而，这些研究结果显示出很大的异质性。德国没有关于汞合金和复合填充物成本或成本效益的出版物。经济分析（荷兰、瑞典、英国）报告称，假设使用寿命相等（观察期为五年）或汞合金的使用寿命比复合填充物更长时，复合填充物的成本更高。这些较高的成本是由于放置复合填充物的复杂性更高。
由于研究设计不同以及研究细节记录不足，很难对后牙中直接汞合金和复合填充物使用寿命的不同研究进行比较。除了进行比较直接填充物使用寿命的随机对照长期研究存在困难外，研究中使用的复合材料和粘合剂在研究发表时往往已被下一代产品取代，这也是一个额外的问题。不仅填充材料，患者参数、局部口腔因素（如填充物的位置）以及治疗牙医都会对牙科填充物的使用寿命产生影响。在评估经济研究时，必须参考医学评估中使用寿命数据的异质性。研究中使用的唯一效果参数是使用寿命，其他方面（如长期功能）仅在讨论中提及。就选择合适的填充材料对患者进行广泛咨询很重要。
汞合金填充物的使用寿命比复合填充物长。六项系统评价中有两项得出结论，复合填充物的预期生存时间可与汞合金填充物相当。然而，这些结论是基于短期研究的结果，这些研究通常高估了填充材料的使用寿命。从经济角度看，将使用寿命作为唯一结果参数时，与后牙中的直接复合填充物相比，汞合金是更经济的填充材料。在个别选择合适的牙科填充材料时，需要考虑使用寿命以外的其他方面。对于未来旨在比较汞合金和复合填充物使用寿命的研究，应争取有足够的样本量和研究周期，最好是在私人牙科诊所的环境中。对汞合金和复合填充物成本效益的评估应考虑牙齿在更长时间段内的功能以及患者的偏好。复合材料和粘合剂的快速发展使得有必要对这些结论进行短期修订。
