Effect of different conditioning methods on the surface roughness of dental amalgam: SEM analysis

Abstract

The purpose of this study was incorporation of SEM micrographs for evaluating the effect of different mechanical and chemical treatments on surface roughness of dental amalgam. Amalgam was condensed in 18 plastic molds and the following modification methods were accomplished on samples surface:

1) Chemical solutions (5 groups) on fresh amalgam 2) Chemical solutions (5 groups) on aged amalgam 3) Sandblast on aged amalgam 4) Sandblast on fresh amalgam (2 groups) before & after primary setting. 5) Use of diamond bur (0.10 coarse) on aged amalgam. 6) Acid etch (37% phosphoric acid) on fresh amalgam. 7) Metal etch on fresh amalgam. 8) Varnish solvent in amalgam capsule, trituration &condensation (fresh). 9) Standard sample without any treatment.

All groups were analyzed by SEM (×l00, ×500 magnifications were used for roughness quantification and chemical analysis respectively). The numbers of surface peaks were counted in 5 area of each micrograph and consequently the data were assessed by K-S & student T- tests.

All groups have statistically significant difference with control except three ones (incorporation of phosphoric acid, EDTA+NH3, and NaOH+I2 on fresh amalgam). Sandblast, diamond bur & metal etch reduced surface roughness and use of chemical solutions showed different reactions.