Quantification of Tooth Stain Using Novel Digital Techniques

Objectives: This study aimed to evaluate and compare the ability of two novel digital imaging systems to detect and quantify tooth stain. Methods: The study was a three cell, randomised clinical trial which was carried out at the Government Dental College, Calicut, India. Subjects (n=169) underwent scaling and polishing and visited the facility twice for clinical and digital evaluation over the 6 week study period. They were randomly assigned to one of three groups: (1) ‘Colgate Cibaca' toothpaste and ‘Clohex' Chlorhexidine mouthwash (0.2% chlorhexidine digluconate); (2) ‘Colgate Cibaca' toothpaste (Control); (3) ‘Colgate Gelkam' gel (anhydrous stannous fluoride). At each attendance, extrinsic stain was scored under blind conditions and under constant lighting conditions, by a trained examiner using the Lobene Stain Index. Digital Images of the labial surfaces of the upper anteriors were captured using a White Light Digital Imaging system. A Quantitative Light Induced Fluorescence system (QLF) was employed to capture fluorescent images of each individual tooth (labial surfaces of 6 upper anterior teeth: Incisors and Canines, and both labial and lingual surfaces of 6 lower anteriors). Results: 139 subjects complied with the protocol and completed the study. Clinical data (stain area and intensity) for both the Gelkam and rinse groups indicated a statistically significant difference (p<0.001) from the control group. The Tooth Whiteness Index (WIO) obtained from the White Light Digital Imaging System was unable to statistically separate the rinse from control but could discriminate Gelkam from Cibaca (p<0.001). The Tooth stain area showed a statistically significant difference (p<0.001) between the products for the QLF data with a higher mean difference for Gelkam compared to the Rinse. Conclusion: The Digital Imaging system could measure diffused stain on the tooth surface which affects the colour values. QLF is more efficient in measuring well defined stain areas on the tooth surface.