Year : 2018

Volume : Volume 8

Issue : Issue 2

Address for correspondence :
Dr. Charushila S Sardar.
charusbs@yahoo.co.in

Abstract

Aim:  To evaluate and compare the surface roughness and stain absorption of two ceramic materials when subjected to reglazing and chair side polishing. Materials and method: Two feldspathic porcelains VITA VMK MASTER (VITA Zahnfabrik, Germany) and CERAMCO 3 (Dentsply International, USA) were used for fabricating 30 ceramic samples to check the efficacy of reglazing and chair side polishing in reducing surface roughness and to correlate the surface roughness with stain absorption after immersing the ceramic samples in Brooke Bond Red Label tea solution for 7 days. These ceramic disc samples were equally divided into 2 groups depending on the material used for fabrication: Group I – VITA VMK MASTER ceramic samples ,Group II – CERAMCO 3 ceramic samples.5 ceramic samples from each group were further subdivided into glazing (control group) (Group I A and II A), reglazing (Group I B and    II B), and chair side polishing (Group I C and II C). Out of 30 ceramic samples, 10 Group I ceramic samples and 10 Group II ceramic samples were subjected to surface roughness by using medium grit diamond point. After surface roughness, 5 Group I ceramic samples and 5 Group II ceramic samples were subjected to reglazing. 5 Group I ceramic samples and 5 Group II ceramic samples were subjected to chair side polishing by using Shofu porcelain adjustment kit. The surface roughness was measured and evaluated with the help of surface profilometer and scanning electron microscope . The readings were noted, tabulated and statistically analyzed. After measuring the surface roughness, the ceramic samples were subjected to spectrophotometric evaluation before immersion in tea solution. After noting the readings the samples were then immersed in tea solution for 7 days at 370C  and evaluated for stain absorption. The difference in the colour shades of all the 30 ceramic samples was calculated, tabulated and analyzed.  Results: The comparison of surface roughness between glazed groups of VITA VMK MASTER and CERAMCO 3 showed the mean surface roughness of 0.083. The comparison of surface roughness between reglazed groups of VITA VMK MASTER and CERAMCO 3 showed the mean surface roughness of 0.088. The comparison of surface roughness between chair side polished  groups of and CERAMCO 3 showed the mean surface roughness of 0.093. The comparison of  “L*” values of glazed, reglazed and chair side polished groups of VITA VMK  MASTER and CERAMCO 3 showed gradual decrease in L* value by the end of 7th day (i.e samples become darker ). The comparison of  “a*” values of glazed, reglazed and chair side polished groups of VITA VMK  MASTER and CERAMCO 3 showed gradual increase in “a*” value by the end of 7th day The comparison of  “b*” values of glazed, reglazed and chair side polished groups of VITA VMK  MASTER and CERAMCO 3 showed gradual decrease in “b*” value by the end of 7th day (i.e samples become darker.Conclusion: The average surface roughness is more in chair side polished groups of VITA VMK MASTER and  CERAMCO  3 than reglazed and glazed groups VITA VMK MASTER and CERAMCO 3. Also chair side polishing showed more stain absorption than reglazing and glazing, thus affecting the colour stability of the ceramics.

Keywords: Reglazing, surface roughness, stain absorption, ceramic.