Open AccessA comparative study of retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements with stainless steel crowns - An in vitro study
Author(s) -
Rajashekar Reddy,
N Basappa,
V V Subba Reddy
Publication year - 2010
Publication title -
journal of the indian society of pedodontics and preventive dentistry/journal of indian society of pedodontics and preventive dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.378
H-Index - 33
eISSN - 1998-3905
pISSN - 0970-4388
DOI - 10.4103/0970-4388.76150
Subject(s) - glass ionomer cement , zinc phosphate , zinc , dentistry , dental cement , materials science , phosphate , metallurgy , medicine , composite material , chemistry , adhesive , layer (electronics) , organic chemistry
An in vitro study was conducted to compare the retentive strengths of zinc phosphate, polycarboxylate and glass ionomer cements using Instron universal testing machine. Thirty preformed and pretrimmed stainless steel crowns were used for cementation on 30 extracted human primary molars which were divided into three groups of 10 teeth in each group. Then the teeth were stored in artificial saliva and incubated at 37°C for 24 h. A load was applied on to the crown and was gradually increased till the crown showed dislodgement, and then the readings were recorded using Instron recorder and analyzed for statistical significance. The surface area of crown was measured by graphical method. The retentive strength was expressed in terms of kg/cm 2 , which was calculated by the equation load divided by area. Retentive strengths of zinc phosphate (ranged from a minimum of 16.93 to amaximum of 28.13 kg/cm 2 with mean of 21.28 kg/cm 2 ) and glass ionomer cement (minimum of 13.69 - 28.15 kg/cm 2 with mean of 20.69 kg/cm 2 ) were greater than that of polycarboxylate cement (minimum of 13.26 - 22.69 kg/cm 2 with mean of 16.79 kg/cm 2 ). Negligible difference (0.59 kg/cm 2 ) of retentive strength was observed between zinc phosphate (21.28 kg/cm 2 ) and glass ionomer cements (20.69 kg/cm 2 ). Glass ionomer cements can be recommended for cementation of stainless steel crowns because of its advantages and the retentive strength was almost similar to that of zinc phosphate cement.