An interventional study of Relative Isolation and Absolute Isolation in Gingival Irritation, sponsored by University of Santiago de Compostela. Completed at 1 site in Spain. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-21.
Sponsored by University of Santiago de Compostela · Not applicable, Interventional, and Prevention
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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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
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. . Relative isolation of the gingival tissues. Two applications of the bleaching agent of 20 minutes
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
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).
Time frame: -15 minutes after the first bleaching session - 15 minutes after the second bleaching session
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
Time frame: 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)
Time frame: Baseline, Before the first bleaching session, Revision (1 week after the 2 bleaching session)
Plan to share: No
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University of Santiago de Compostela