Date of Award

Fall 2022

Document Type


Degree Name

Master of Science (MS)



First Advisor

Berzins, David W.

Second Advisor

Dix, Christopher

Third Advisor

Toth, Jeffrey M.


Objective: For many years, the conventional method to achieve a white smile has been chemical regimens such as peroxide compounds. Previous studies suggest risks associated with chemical procedures, so many are seeking out alternative options such as utilizing activated charcoal. Since this new method is rapidly trending, there have not been many scientific studies on how utilizing activated charcoal can affect the mechanical/physical properties of tooth structure. The primary objective of this study was to investigate the effect of activated charcoal on enamel’s mechanical/physical properties and compare it to a conventional tooth whitening method (carbamide peroxide). Materials and Methods: Extracted adult human molars and premolars with no/minimal restorations and/or decay were collected from local dental offices and disinfected with 1% thymol solution for 48 hours. A total of 30 collected teeth were prepared and sliced in half, resulting in 60 specimens (n=60) that were stained with coffee for 72 hours. The samples were randomly assorted into six groups with 10 samples per group: Control without Brushing (CW), Control with Brushing (CWB), Activated Charcoal/Dab (ACNB), Activated Charcoal/Brush (ACB), Opalescence 20%/Brush (OPB) and Opalescence 20%/Dab (OPNB)). Each group was treated accordingly for 14 days. All groups were tested for color, hardness and surface roughness via a spectrophotometer, Vickers hardness and a 3D measuring laser microscope, respectively. Data were analyzed by a multiple variable linear regression model with a significance level at P < 0.002. Results: Over a period of 14 days, OPNB produced a significantly greater color change (Eab and E00) compared to the Activated Charcoal and Control Groups. Treatment with Activated Charcoal significantly changed color more than the Control without Brushing, but not the Control with Brushing. The greatest contributor to E was a change in L* (lightening/whitening). Brushing had a negative effect on the whitening of the Opalescence treatment. No significant differences were found for microhardness and surface roughness amongst the six groups within 14 days of treatment. Conclusion: In general, chemical whitening with carbamide peroxide was more effective than using activated charcoal in treating stained enamel. Both whitening methods were not detrimental to enamel in this in vitro study as they did not alter microhardness or surface roughness.

Included in

Dentistry Commons