Abstract
Recently in the clinical practice of pedodontics metal inlay restoration is used more frequent than silver amalgam restoration. Because of the anatomical characteristics of primary teeth, dentists have a tendency to expose the pulp during the cavity preparation on primary teeth. When preparating cavity, it is important to be aware of the spatial relation between the cavity and pulp chamber. However, there appear to be no reports concerning the cavity form for the metal inlay in primary molars.
The purpose of this study was to investigate the spatial relation between the cavity and pulp chamber in metal inlay restorations. The experimental teeth were 17 mandibular primary first molars. Disto-occlusal cavities were prepared for inlay restoration. Impressions were taken with silicon rubber impression material to make plaster models.
These teeth were decalcified with nitric acid and ethanol, embedded in celloidin, sectioned serially in buccolingual ( 8 teeth), horizontal ( 9 teeth)direction and stained with hematoxylin-eosin. Then, the distance from cavity to the pulp chamber were measured.
Results were as follows.
1. In the occlusal cavity, the shortest distance between the cavity and pulp chamber was 0.16-0.49 mm on the average. In the crown of mandibular primary first molar these positions corresponded to the adjacent mesiobuccal and mesiolingual cusp. The mesiobuccalhorn was the highest horn of the pulp chamber, it extended above the pulpal wall about 0.55mm.
2. In the proximal box, the positions of the shortest distance between the cavity and pulp chamber were corresponded to the gingival one-fourth of buccoaxial line angle and the adjacent the linguo-axial-gingival point angle.
3. The positions of the most thick distance between the cavity wall and pulp chamber were corresponded to the vicinity of buccal groove and lingual groove.
