Enamel damages caused by contracting restorative resins

Several observations have shown that contraction stresses in restorative resins bonded to the enamel of cavity walls readily broke the enamel surrounding the cavities. The forces studied were caused by polymerization contraction, thermal contraction or elastic hysteresis. The bonding was obtained mainly by etching the cavity walls by phosphoric acid.

[Importance of silicone bases in complete dentures]

The use of a silicone base under a total prosthesis makes possible the solution of certain problems of tolerance or maintenance of such denture. I.--Full denture in patients who have received radiotherapy. II.--Full denture with intolerant mucosa. III.--Following failure of classical prosthesis. IV--Prosthesis fitted following pre-prosthetic surgery. The technical problems associated with the fabrication of such prosthesis and possible adjustements are discussed.

Cardiovascular effects of acrylic bone cement in rabbits and cats

The cardiovascular responses to forcing acrylic bone cement, Plasticine, or soft paraffin wax into the medullary cavity of the femur have been studied in rabbits and cats. An acute fall in blood pressure, occurring within a few seconds of insertion, was demonstrated with each substance. In a few of the animals the blood pressure response had a second more protracted component and it is suggested that more than one mechanism is involved. The cardiovascular effects that have been observed in man when acrylic cement is used in prosthetic hip surgery also may be due to more than one mechanism.