Salis S G, Hood J A, Kirk E E, Stokes A N
J Prosthet Dent. 1987 Jul;58(1):43-8. doi: 10.1016/s0022-3913(87)80140-3.
The fracture strength of contralateral pairs of premolar teeth was determined by an in vitro method wherein impact loads of equal energy were applied to the medial aspects of the buccal cusps. Absorbed energy values quantified the fracture resistance of unprepared teeth and teeth restored with MOD amalgams, MOD amalgam overlays, MOD gold overlays, and full gold crowns. It was established that unprepared lower premolar teeth had a greater resistance to fracture than upper premolar teeth, and lower first premolar teeth were more resistant to fracture than the other premolar teeth; the fracture resistance of premolar teeth restored with MOD amalgams was significantly reduced compared with unprepared control teeth; MOD amalgam overlays in premolar teeth produced fracture resistances not significantly different from those for the unprepared controls; and restoration of premolar teeth with MOD gold overlays and full gold crowns enhanced fracture resistance to a level much greater than that of the unprepared control teeth.
通过一种体外方法测定对侧前磨牙的断裂强度，该方法是对颊尖的内侧施加能量相等的冲击载荷。吸收能量值量化了未预备牙齿以及用MOD银汞合金、MOD银汞合金覆盖物、MOD金覆盖物和全金冠修复的牙齿的抗断裂能力。结果表明，未预备的下颌前磨牙比上颌前磨牙具有更大的抗断裂能力，且下颌第一前磨牙比其他前磨牙更抗断裂；与未预备的对照牙齿相比，用MOD银汞合金修复的前磨牙的抗断裂能力显著降低；前磨牙使用MOD银汞合金覆盖物产生的抗断裂能力与未预备的对照牙齿无显著差异；用MOD金覆盖物和全金冠修复前磨牙可将抗断裂能力提高到远高于未预备对照牙齿的水平。
