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

A Double Blind Randomized Clinical Trial Comparing the Risk of Gingival Irritation of Two Different Isolation Techniques Performed During 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).

Study Overview

• Status: Completed
• Conditions: Gingival Irritation
• Intervention / Treatment: Device: Relative Isolation; Device: Absolute Isolation

Detailed Description

1. 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.
2. 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)

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • A Coruña
    • Santiago de Compostela, A Coruña, Spain, 15705
      • School of Medicine and Dentistry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Relative Isolation; The relative isolation technique consists in inserting a lip retractor (OptraGate, Ivoclar Vivadent) and applying a gingival barrier resin (OpalDam, Ultradent Products) along the gingival margin, extending approximately 2-3 mm onto the enamel.	Device: Relative Isolation; 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
Experimental: Absolute isolation; The total rubber dam isolation was carried out placing the dam (Flexidam non latex; Roeko) from premolar to premolar in both arches and stabilizing it with clamps (B4; Hygenic). Dental silk ligatures were used to achieve proper cervical retraction.	Device: Absolute Isolation; 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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gingival Evaluation Recording	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).	-15 minutes after the first bleaching session - 15 minutes after the second bleaching session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Questionary of dental sensitivity	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	Perioperative , 1 hour postoperative, 24 hours postoperative, 48 hours postoperative.
Shade evaluation of each patient	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)	Baseline, Before the first bleaching session, Revision (1 week after the 2 bleaching session)

Collaborators and Investigators

• Sponsor: University of Santiago de Compostela

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2025
• Primary Completion (Actual): July 16, 2025
• Study Completion (Actual): July 16, 2025

Study Registration Dates

• First Submitted: December 10, 2025
• First Submitted That Met QC Criteria: January 12, 2026
• First Posted (Actual): January 21, 2026

Study Record Updates

• Last Update Posted (Actual): January 21, 2026
• Last Update Submitted That Met QC Criteria: January 12, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Isolation; Vital Bleaching; Gingival irritation; In-Office bleaching
• Other Study ID Numbers: 2025/02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No