Chamunorwa Marufu

Chamunorwa Marufu

Chamunorwa Marufu graduated from the University of Zimbabwe with a Bachelor of Dental Surgery degree. He worked in government and the private sector before resuming his studies pursuing a Master of Dental Surgery degree in Prosthodontics at the University of Nairobi. He has a special interest in aesthetic dentistry which motivated him to do a study on the colour stability of resin composite materials used for aesthetic restorations.

Project Summary

Effect of Polishing Protocol and Staining Solutions on Colour Stability of Resin Composites

Objective: The objective of this study was to evaluate the effect of surface finishing protocol and exposure to staining solutions on the colour stability of dental resin composite restorative materials

Methods: Two commercial dental resin composite materials, a nano-fill composite and a micro-hybrid composite and three finishing and polishing protocols, mylar strip finish, Soflex polishing discs and white polishing stone were evaluated. The staining solutions were tea, red wine and khat extract. Distilled water was the control for staining solutions. A digital spectrophotometer was used for all colour measurements which were done using the CIE-Lab-colour (Commission International de l’ Eclairage L*a*b colour) system.

Results: In the microhybrid group, Soflex disc finished specimens recorded the least mean ΔE whilst mylar finished specimens demonstrated the highest ΔE. In the nanofill group, white polishing stone demonstrated the highest ΔE in all the staining solutions while Soflex discs demonstrated the least ΔE in all the staining solutions with the exception of the red wine staining group where mylar finished specimens demonstrated the least ΔE. Comparing the two materials, the microhybid composite showed better colour stability compared to the nanofill when finished with Soflex discs and white polishing stone, while the nanofill had better colour stability with the mylar finish in the staining solutions used in the study. The staining solutions did not show any clear pattern as to which produces the highest ΔE.

Conclusion: There is a difference in colour stability of resin composites depending on the type of material and the finishing protocol.

Research supervisors

  1. Bernina K. Kisumbi B.K, Senior Lecturer, Biomaterials Science
  2. Olivia A. Osiro, Lecturer, Biomaterials Science
  3. Fred O. Otieno, Lecturer, Restorative dentistry