Baldissara P, Comin G, Martone F, Scotti R
Department of Prosthodontics, University of Bologna, School of Dentistry, Italy.
J Prosthet Dent. 1998 Oct;80(4):417-22. doi: 10.1016/s0022-3913(98)70005-8.
In many situations, provisional restorations require a long-term permanence in the oral cavity. During this period, the abutments need the best possible biologic and mechanical protection. In this way, the vitality of the pulp and the integrity of mineralized tissues can be preserved. The luting cement used to fix interim restorations should have good mechanical properties, low solubility, and good adhesion to resist bacterial and molecular penetration. However, because of its provisional nature, the prosthesis should be easy to remove from the abutments. These contrasting requirements may lead to a compromise in cement behavior, particularly in its mechanical properties.
This in vitro study evaluated the marginal microleakage of 4 provisional cements, a cavity base compound and a zinc-phosphate luting cement in provisional acrylic resin crowns fixed on extracted human teeth.
Thirty acrylic resin crowns were made and fitted on intact human premolars with the 6 cements. All restorations were applied in a standardized manner by means of an axial load of 10 kg. Specimens were thermocycled then submerged in a 5% basic fuchsin solution, then sectioned and observed under a light stereomicroscope. A 5-level scale was used to score dye penetration in the tooth/cement interface.
A high dye penetration in the tooth/cement interface was present in all 4 provisional cements. Microleakage existed in specimens where zinc-phosphate and cavity base compounds were used; however, it was lower than the other materials. A significant difference (P < .05) was found between zinc-phosphate and one eugenol-free cement and between cavity base and the same eugenol-free cement.
All materials tested demonstrated different degrees of microleakage. Zinc-phosphate and cavity base compound cements had the best sealing properties. This latter, even if conceived as a cavity base, may be considered a good provisional cement as far as microleakage is concerned.
在许多情况下，临时修复体需要在口腔中长期留存。在此期间，基牙需要尽可能好的生物和机械保护。通过这种方式，可以保存牙髓的活力和矿化组织的完整性。用于固定临时修复体的粘结水门汀应具有良好的机械性能、低溶解性和良好的附着力，以抵抗细菌和分子渗透。然而，由于其临时性，修复体应易于从基牙上取下。这些相互矛盾的要求可能导致水门汀性能的折衷，特别是在其机械性能方面。
本体外研究评估了4种临时水门汀、1种洞衬剂和1种磷酸锌粘结水门汀在固定于拔除的人牙上的临时丙烯酸树脂冠中的边缘微渗漏情况。
制作30个丙烯酸树脂冠，并用6种水门汀安装在完整的人前磨牙上。所有修复体均通过10 kg的轴向载荷以标准化方式施加。将标本进行热循环处理，然后浸入5%的碱性品红溶液中，然后切片并在光学立体显微镜下观察。使用5级评分量表对牙齿/水门汀界面处的染料渗透进行评分。
所有4种临时水门汀在牙齿/水门汀界面处均有较高的染料渗透。使用磷酸锌和洞衬剂的标本中存在微渗漏；然而，其低于其他材料。在磷酸锌和一种不含丁香酚的水门汀之间以及洞衬剂和同一种不含丁香酚的水门汀之间发现了显著差异（P <.05）。
所有测试材料均表现出不同程度的微渗漏。磷酸锌和洞衬剂水门汀具有最佳的密封性能。就微渗漏而言，后者即使被视为洞衬剂，也可被认为是一种良好的临时水门汀。
