Introduction
Materials and methods
Selection of the study group: inclusion and exclusion criteria
Study phases and mouthwash protocols
Staining of dental plaque and intraoral photography
-
One rinse for 10 s with 20 ml of phosphate buffer.
-
One rinse for one minute with 15 ml of 1240 parts per million (ppm) fluorescein in a phosphate buffer.
-
Three rinses for 10 s with 25 ml of phosphate buffer.
Analysis of the intraoral photographs using the DenTiUS Deep Plaque software
-
Plaque area: Percentage of the tooth surface with dental plaque.
-
Plaque growth area: The growth rate of the dental plaque area per unit of time in hours (percentage area/hour).
Statistical analysis
-
Inter-mouthwash analysis between independent groups: test group A vs. test group B in phase 1 (cymenol and placebo mouthwashes, respectively); test group A vs. test group B in phase 2 (cymenol mouthwashes in both groups). After using the Shapiro-Wilk test to determine the normal distribution of the data, either the Student’s t-test for independent samples (normal distribution) or the Mann-Whitney U (non-normal distribution) test was employed to compare the means obtained in both groups with the DenTiUS Deep Plaque clinical indices at baseline (day 0) and after using the mouthwash (days 4 and 8). In all cases, statistical significance was set as p < 0.05.
-
Inter-mouthwash analysis in a paired group: test group A in phase 1 (cymenol mouthwash) vs. phase 2 (cymenol mouthwash), and test group B in phase 1 (placebo mouthwash) vs. phase 2 (cymenol mouthwash). After testing for the normal distribution of the data using the Shapiro-Wilk test, either the repeated measures ANOVA (normal distribution) or the Wilcoxon test (non-normal distribution) and post hoc tests were applied with the Bonferroni correction to obtain a pairwise comparison of the DenTiUS Deep Plaque (DDP) clinical indices for a particular study group at the different timepoints (days 0, 4, and 8). In all cases, statistical significance was set as a p-corrected value < 0.016.
Results
Clinical characteristics of the study groups
Clinical parameters registered | Test group A (n = 24) | Test group B (n = 26) | p-value |
---|---|---|---|
Age (years) | 21.87 ± 1.51 | 22.00 ± 3.07 | 0.835 |
Gender | |||
Men | 10 | 6 | |
Women | 14 | 20 | 0.227 |
Number of teeth | 28.54 ± 1.69 | 29.03 ± 1.56 | 0.284 |
Bacterial plaque (%) | 6.20 ± 6.00 | 6.40 ± 6.20 | 0.914 |
Gingival bleeding (%) | 3.20 ± 3.00 | 3.40 ± 3.20 | 0.821 |
Probing pocket depth (mm) | 1.79 ± 0.22 | 1.70 ± 0.24 | 0.184 |
Inter-mouthwash analysis between independent groups: test group A vs. test group B in phases 1 and 2
DenTiUS Deep Plaque clinical indices | Test group A (Mean % ± S.D.) | Test group B (Mean % ± S.D.) | p-value |
---|---|---|---|
Phase 1_Day 0 | |||
Visible plaque area (absolute) | 5.57 ± 3.57 | 5.68 ± 3.53 | 0.906 |
Phase 1_Day 4 | |||
Visible plaque area (absolute) | 35.31 ± 14.93 | 46.57 ± 18.92 | 0.023 |
Visible plaque area (relative) | 29.80 ± 13.97 | 40.53 ± 18.48 | 0.024 |
Total plaque area | 57.49 ± 13.26 | 62.75 ± 16.85 | 0.225 |
Visible plaque area growth (absolute) | 0.36 ± 0.15 | 0.49 ± 0.20 | 0.016 |
Visible plaque area growth (relative) | 0.31 ± 0.14 | 0.43 ± 0.19 | 0.017 |
Total plaque area growth | 0.60 ± 0.13 | 0.66 ± 0.17 | 0.150 |
Phase 2_Day 8 | |||
Visible plaque area (absolute) | 44.79 ± 15.77 | 65.12 ± 16.37 | < 0.001 |
Visible plaque area (relative) | 39.27 ± 14.33 | 59.24 ± 16.90 | < 0.001 |
Total plaque area | 65.17 ± 9.73 | 74.52 ± 13.55 | 0.007* |
Visible plaque area growth (absolute) | 0.23 ± 0.08 | 0.34 ± 0.08 | < 0.001 |
Visible plaque area growth (relative) | 0.20 ± 0.07 | 0.31 ± 0.08 | < 0.001 |
Total plaque area growth | 0.34 ± 0.05 | 0.39 ± 0.07 | 0.005* |
Inter-mouthwash analysis in a paired group: test group A, phase 1 (cymenol mouthwash) vs. phase 2 (cymenol mouthwash)
DenTiUS Deep Plaque clinical indices | Test group A | p-value | |
---|---|---|---|
Phase 1_Day 4 (Mean % ± S.D.) | Phase 2_Day 8 (Mean % ± S.D.) | ||
Visible plaque area (absolute) | 35.31 ± 14.93 | 44.79 ± 15.77 | 0.001 |
Visible plaque area (relative) | 29.80 ± 13.97 | 39.27 ± 14.33 | 0.001 |
Non-visible plaque area | 27.69 ± 11.27 | 25.89 ± 10.37 | 0.262 |
Total plaque area | 57.49 ± 13.26 | 65.17 ± 9.73 | 0.004* |
Visible plaque area growth (absolute) | 0.36 ± 0.15 | 0.23 ± 0.08 | < 0.001 |
Visible plaque area growth (relative) | 0.31 ± 0.14 | 0.20 ± 0.07 | < 0.001 |
Total plaque area growth | 0.60 ± 0.13 | 0.34 ± 0.05 | < 0.001* |
Inter-mouthwash analysis in a paired group: test group B, phase 1 (placebo mouthwash) vs. phase 2 (cymenol mouthwash)
DenTiUS Deep Plaque clinical indices | Test group B | p-value | |
---|---|---|---|
Phase 1_Day 4 (Mean % ± S.D.) | Phase 2_Day 8 (Mean % ± S.D.) | ||
Visible plaque area (absolute) | 46.57 ± 18.92 | 65.12 ± 16.37 | < 0.001 |
Visible plaque area (relative) | 40.53 ± 18.48 | 59.24 ± 16.90 | < 0.001 |
Total plaque area | 62.75 ± 16.85 | 74.52 ± 13.55 | < 0.001 |
Visible plaque area growth (absolute) | 0.49 ± 0.20 | 0.34 ± 0.08 | < 0.001 |
Visible plaque area growth (relative) | 0.43 ± 0.19 | 0.31 ± 0.08 | 0.001 |
Total plaque area growth | 0.67 ± 0.18 | 0.39 ± 0.07 | < 0.001 |