Determination of a Threshold for Mouth Rinse Induced Discoloration of Teeth


The purpose of this study is to daily monitor the discoloration of teeth when participants rinse with a mouth rinse and black tea and to determine the time point when unacceptable discoloration occurs.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Masking: None (Open Label)
  • Study Primary Completion Date: May 2011

Detailed Description

Tooth discoloration is a side effect of most mouth rinse solutions. It impairs the aesthetic appearance especially of the front teeth. The aim of this pilot study is to determine a time point when visible discoloration appears in the front teeth. Therefore, participants of this study will rinse twice daily with chlorhexidine mouth rinse for 10 days. To elicit a more pronounced discoloration, participants will rinse with black tea right after the chlorhexidine rinse. Discoloration will be measured daily by discoloration index, by spectrophotometry, and by the use of a digital photo.


  • Other: chlorhexidine 0.12%
    • twice daily, 10 ml, topical

Arms, Groups and Cohorts

  • Experimental: chlorhexidine 0.12 %

Clinical Trial Outcome Measures

Primary Measures

  • Time point (day) when delta E > 2
    • Time Frame: 11 days

Secondary Measures

  • Time point (day) when discoloration index changes compared to baseline
    • Time Frame: 11 days
  • Time point (day) when changes in the photo evaluation occur compared to baseline
    • Time Frame: 11 days
  • Time point (day) when discoloration occurs subjectively (questionnaire) compared to baseline
    • Time Frame: 11 days

Participating in This Clinical Trial

Inclusion Criteria

  • persons aged 18 to 30 years – written informed consent – healthy participants – participants who have no or mild gingivitis – participants who have all incisors and canines in the upper and lower jaw Exclusion Criteria:

  • participants who have severe general diseases – participants who have allergies against the ingredients of the mouthrinse – participants who are enrolled in another clinical study – participants who are not able to oversee the consequences of the study – female participants who are pregnant or breast feeding – participants who have impaired compliance – participants who have moderate or severe gingivitis – participants who have fillings in the incisors and canines – participants who smoke

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 30 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Technische Universität Dresden
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Thomas Hoffmann, Prof. Dr., Principal Investigator, Technische Universität Dresden


Addy M, Prayitno S, Taylor L, Cadogan S. An in vitro study of the role of dietary factors in the aetiology of tooth staining associated with the use of chlorhexidine. J Periodontal Res. 1979 Sep;14(5):403-10. doi: 10.1111/j.1600-0765.1979.tb00238.x. No abstract available.

Bengel WM. Digital photography and the assessment of therapeutic results after bleaching procedures. J Esthet Restor Dent. 2003;15 Suppl 1:S21-32; discussion S32. doi: 10.1111/j.1708-8240.2003.tb00315.x.

Denissen H, Dozic A. Photometric assessment of tooth color using commonly available software. Eur J Esthet Dent. 2010 Summer;5(2):204-15.

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