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Effects of Repeated Hand Instrumentation on the Marginal Portion of a Cast Gold Crown
Author(s) -
Yagi Hiroaki,
Ito Koichi,
Eda Masahiro,
Murai Seidai
Publication year - 1998
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.1998.69.1.41
Subject(s) - polishing , crown (dentistry) , surface roughness , silicone rubber , materials science , surface finish , dentistry , orthodontics , composite material , medicine
A study was conducted to evaluate the effects of repeated hand instrumentation on the marginal portion of a cast gold crown. Seven extracted periodontally diseased premolare were used. The finishing line of the preparation was placed on the root surface and then the crown was cast and cemented in the usual manner. One proximal surface of each sample was divided into 2 areas: root planing (RP) area and RP plus polishing (RPP) area. The marginal portion of the crown was measured to give a baseline value using a surface roughness‐ and profile‐analyzing system. Then, the marginal portion was painted with a waterproof pen. RP was performed to remove paint in the RP are'a with the curets. In the RPP area, RP followed by polishing was done by silicone polishing points and a rubber cup with polishing paste. The relevant procedures and measurements were repeated 3 times in each area. Changes in the sample roughness and profile were evaluated and compared between the 2 techniques. The results showed that repeated instrumentation altered the surface of the marginal portion of the cast gold crown, resulting in increased roughness in both areas ( P < 0.01). However, the roughness of the RPP area was considerably restored to the baseline value by polishing after RP. Therefore, it is suggested that polishing after RP smoothes the marginal portion of the cast gold crowns and appears to be an efficient prophylactic system. J Periodontol 1998;69:41–46 .