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Completed

NCT Number: NCT07355673

The Influence of Isolation Techniques in Gingival Irritation During an In-office Bleaching

The objective of this study was to evaluate if two different isolation techniques used during in-office bleaching influence the risk of gingival irritation. The secondary objectives were to investigate whether the isolation technique affects bleaching efficacy, the occurrence of tooth sensitivity, and the intensity of tooth sensitivity (TS).

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Key information

Conditions

Gingival Irritation

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

School of Medicine and Dentistry

Santiago de Compostela, A Coruña, 15705, Spain

About this study

  • Visit 1: Study information and delivery of informed consent. Recording of patient's medical history, general examination, and prophylaxis. Alginate impressions will be taken of the upper and lower arches for all the patients who meet the inclusion criteria. The impressions will be poured into plaster, and a positioning guide-finder tray will be fabricated for each patient for color measurement.
  • Visit 2: Initial color measurement with a spectrophotometer and the positioning guide. Two clinicians performed the assigned isolation technique (relative or absolute). Then after a correct isolation the clinicians apply over the buccal surface from premolar to premolar of both arches the bleaching agent (Opalescence Boost 40%, Ultradent Products, South Jordan, USA).Two application of 20 minutes each. Objective examination of gingival tissues was performed visually, documented with photographs, and verified using a periodontal probe. The sensitivity was recorded and patient were given a sensitivity test to record at home. c) Visit 3: One week after the first bleaching session. Color measurement with a spectrophotometer and the positioning guide. In this visit the second bleaching session was done with the same steps as visit 2. d) Visit 4: 15 days after the second bleaching session. Final data collection (color + patients sensitivity test)

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • No oral os systemic pathology
  • Periodontally Healthy
  • No cavities
  • Tooth shade of the canines A2 or darker

Exclusion criteria

  • Adhesive restorations or protheses in the anterior region
  • Enamel or dentin alterations
  • Smoking habits
  • Pregnant women
  • Undergone prior bleaching treatment

Treatment and study plan

Relative Isolation

Device

General Examination with bite-wings, dental prophylaxis, alginate impressions of both arches, creation of individualized bleaching trays and position finder trays. . Relative isolation of the gingival tissues. Two applications of the bleaching agent of 20 minutes

Absolute Isolation

Device

General Examination with bite-wings, dental prophylaxis, alginate impressions of both arches, creation of individualized bleaching trays and position finder trays. . Absolute isolation of the gingival tissues. Two applications of the bleaching agent of 20 minutes

Primary outcomes

  1. Gingival Evaluation Recording

    Time frame: -15 minutes after the first bleaching session - 15 minutes after the second bleaching session

    Objective examination of gingival tissues was performed visually, documented with photographs, and verified using a periodontal probe. Patients were classified according to the Löe and Silness' gingival index as follows: G0 =normal gingiva; G1=mild inflammation (slight color change, slight edema, no bleeding on probing); G2=moderate inflammation (redness, edema, glazing, bleeding on probing); and G3=severe inflammation (marked redness and edema, ulceration, spontaneous bleeding).

Secondary outcomes

  1. Questionary of dental sensitivity

    Time frame: Perioperative , 1 hour postoperative, 24 hours postoperative, 48 hours postoperative.

    General tooth sensitivity was assessed using a 5-point Numeric Rating Scale (NRS), where 0 = no sensitivity; 1 = mild discomfort; 2 = moderate discomfort that does not interfere with daily activities; 3 = considerable discomfort leading to avoidance of certain foods and beverages; and 4 = severe sensitivity requiring interruption of the bleaching treatment. Participants selected the numeric value that best represented their perceived level of tooth sensitivity.

    Pain intensity was recorded at the following time points:

    • Perioperative
    • 1 hour postoperatively
    • 24 hours postoperatively
    • 48 hours postoperatively

  2. Shade evaluation of each patient

    Time frame: Baseline, Before the first bleaching session, Revision (1 week after the 2 bleaching session)

    Tooth color will be measured using a dental spectrophotometer, recording the following parameters: L (lightness, representing the shade from black to white on a scale of 0 to 100), a (color variation along the red-green axis, with positive values toward red/purple and negative values toward green/blue), b (color variation along the yellow-blue axis, with positive values toward yellow and negative values toward blue/purple), C (chroma, describing the intensity or saturation of a color, expressed on a scale from 0 to 40, where 0 indicates no saturation and 40 the maximum saturation), and hº (hue, representing the dominant wavelength of a color on a continuous circular scale from 0° to 360°).

    Color changes between visits will be calculated using the CIELab, CIEDE2000, and White Index for Dentistry (WID) formulas.

    Color measurements will be recorded at the following time points:

    Baseline (Bleaching Day 1) One week after baseline (Before Bleaching Day 2) Follow-up (One week after)

Sponsors and collaborators

Lead sponsor

University of Santiago de Compostela

Other

Registry information

Official study title

A Double Blind Randomized Clinical Trial Comparing the Risk of Gingival Irritation of Two Different Isolation Techniques Performed During In-Office Bleaching

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jan 21, 2026
Registry last updated
Jan 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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