[Comparative study of the sealing properties of retrograde amalgam root fillings using a microtechnic and the naked eye].

The aim of the present investigation was to compare the quality of retrograde amalgam fillings made under the control of the naked eye and that of a stereomicroscope. The 58 extracted upper incisors used for study had been divided into two groups and were filled with one of the control methods. In both groups on 25 teeth the microleakage was assessed by dye diffusion, the surfaces of the remaining 4 teeth were subjected to SEM examination. The depths and angle belonging to the stained sections of the perimeter had been measured under a stereomicroscope with a magnification of 40 and the area affected was calculated. Significantly (p less than 0.001) less area was involved in the stereomicroscopic group (1.46 +/- 0.34 mm2) than in the naked eye group (3.89 +/- 1.80 mm2). The SEM photographs demonstrated the faults which can be eliminated by the use of a stereomicroscope and showed also those which derive from the physical and chemical properties of the amalgam.