Effect of coffee roasting level on tooth discoloration

Purpose: Coffee consumption is a well-known contributor to tooth discoloration, and the extent of staining is influenced by the chemical composition of the coffee. This study investigated the associations of coffee roasting level, chlorogenic acid (CGA) content, absorbance level, and their combined effects with tooth discoloration. Methods: Bovine tooth enamel specimens were immersed in light, medium, and dark roasts of four coffee types (two Arabica and two Robusta coffees) for 72 h. High-performance liquid chromatography (HPLC) was used to measure CGA content, absorbance levels were estimated by using pigment concentration, and discoloration was assessed by spectrophotometry. The data were analyzed with the Friedman test. Results: Medium roasts induced the greatest discoloration, and tooth specimens immersed in Ethiopia Arabica exhibited the greatest color difference based on CIEDE2000 (Delta E00 at 72 h: 13.51 +/- 4.63). Light roasts induced the least staining, despite having the highest CGA content. Dark roasts showed the highest absorbance, indicating a higher pigment concentration. Friedman analysis revealed a significant difference in color change in relation to roasting level for all coffee types. Conclusion: The present findings indicate that tooth discoloration is caused by the complex interaction of CGA, melanoidins, and roasting level. Because of the interplay of these factors, medium roasting had the greatest effect on discoloration.