A novel optical approach to achieving tooth whitening.
OBJECTIVE
To investigate a new optical approach to tooth whitening by enhancing the measurement and perception of tooth whiteness using blue coloured materials deposited onto the tooth surface.


METHODS
Salivary pellicle coated human extracted teeth or polished enamel specimens were used as substrates and their colour was measured using a colorimeter in the CIELAB mode. Whole teeth were treated with a range of blue dyes and pigments and the colour measured following rinsing with water. Whole teeth were treated with Blue Covarine for 30 s, rinsed with water and colour changes assessed via colorimetric and visual assessment with a Vita Shade guide under controlled lighting (D65). Deposition of Blue Covarine onto cut enamel specimens was investigated using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Tooth colour changes were also investigated following brushing for 1 min with toothpaste formulations containing Blue Covarine.


RESULTS
Blue Covarine gave a significantly greater deltab* shift (p < 0.0001) compared to water. Blue Covarine gave a mean Vita Shade change of 1.18 compared to the water control (-0.03) (p <0.0001) and an increase in objectively measured whiteness index (WIO) (p <0.0001). Blue Covarine was chemically detected on enamel surfaces using TOF-SIMS. Toothpaste formulations containing Blue Covarine gave improvements in tooth whiteness.


CONCLUSIONS
Blue Covarine has been identified as a new approach to tooth whitening. Its mode of action involves deposition and retention on tooth surfaces where it alters the optical properties of the tooth. This gives rise to an increase in the overall measurement and perception of tooth whiteness.
Joiner
Andrew
A
Unilever Oral Care, Quarry Road East, Bebington, Wirral CH63 3JW, UK. Andrew.Joiner@Unilever.com
Philpotts
Carole J
CJ
Alonso
Coralie
C
Ashcroft
Alex T
AT
Sygrove
Naomi J
NJ
D001391:Azo Compounds / Q000008:administration & dosage / Q000494:pharmacology; D001557:Benzenesulfonates / Q000008:administration & dosage / Q000494:pharmacology; D003116:Color; D003118:Color Perception / Q000502:physiology; D003124:Colorimetry; D004396:Coloring Agents / Q000008:administration & dosage / Q000494:pharmacology*; D003743:Dental Enamel / Q000033:anatomy & histology / Q000187:drug effects; D044622:Dental Pellicle / Q000033:anatomy & histology / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007211:Indoles / Q000008:administration & dosage / Q000494:pharmacology*; D054833:Isoindoles / Q000494:pharmacology*; D008029:Lighting; D008665:Metalloporphyrins / Q000494:pharmacology*; D055095:Optics and Photonics; D017797:Prosthesis Coloring / Q000295:instrumentation; D012394:Rosaniline Dyes / Q000008:administration & dosage / Q000494:pharmacology; D018629:Spectrometry, Mass, Secondary Ion; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D014100:Toothpastes / Q000008:administration & dosage / Q000494:pharmacology; D014867:Water / Q000737:chemistry
D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; D007211:Indoles; D054833:Isoindoles; D008665:Metalloporphyrins; D012394:Rosaniline Dyes; D014100:Toothpastes; C532297:blue covarine; D014867:Water; C000298:brilliant black 1; C008769:sulfan blue; C006796:brilliant blue; C013647:phthalocyanine