Abstract
The major factor for a successful subperiosteal implant depends on sufficient membrane peeling and precision impression taking. However, it must be noted that perfect impression taking is a requirement that must be fulfilled within a period of limited effective time of anesthesia and intermittent treatment of the subject. Therefore, in the prior study, the operability and features of various individual tray materials in combination with precision rubber impression materials were compared to establish an ideal impression taking method of the bone surface. In this study, the individual tray materials, applied in various cases to gain insight into some subperiosteal implant impression methods, were as follows
(1) Room temperature curing resin: Ostron 100 (GC)
(2) Light-activated resin: Eporex Rebase (Nippon Oil＆ Fats Co., Ltd.)
(3) Thermoplastic resin 1: Erkoplast (Erko-dent)
(4) Thermoplastic resin 2: heat forming (Shofu Inc.)
Since impression taking of the bone surface is conducted within a limited period of time and operating field, corrective performance of the individual tray becomes a major issue. Among the four types of impression materials it was found that heat forming was the most ideal material in this respect, because it was capable of correction in warm water, being a thermoplastic resin. By combining it with the express system, that is, a machine mixed type-hydrophilic vinyl silicone impression material, it was found that the impression taking time could be shortened or lengthened almost in accordance with the operator's intentions.
