Jung Katja, Eilert Franziska, Ganss Carolina
Department of Operative Dentistry, Endodontics and Paediatric Dentistry, Section Cariology, Dental Clinic of the Philipps-University Marburg, Marburg, Germany.
Department of Restorative Dentistry and Endodontology, Dental Clinic, Justus-Liebig-University Giessen, Giessen, Germany.
Caries Res. 2025 Jul 21:1-13. doi: 10.1159/000547456.
Clinical plaque indices are well-established methods for quantifying the effects of plaque control, for example, with different toothbrush types. However, effect sizes observed in such studies depend on the index used. Therefore, this study aimed to evaluate how Turesky-modified Quigley-Hein Plaque Index (T-QHPI), Rustogi-modified Navy Plaque Index (RMNPI), and RMNPI modified by Bretz (RMNPI-Bretz) scores correspond to actual plaque amounts.
Thirty participants, 24.0 ± 4.1 years old, were included. Following 72 h without oral hygiene and after subsequent habitual toothbrushing, disclosed plaque (Mira-2-Ton®) was captured using intraoral scans (Carestream 3800). Scoring grids corresponding to the indices were projected onto standardised images on the oral and vestibular sides of the Ramfjord teeth (16, 21, 24, 36, 41, and 44) and scored. Afterwards, actual plaque coverage was quantified planimetrically (P%).
All methods yield significant plaque reduction after brushing (P%: 42.1 ± 14.0%, T-QHPI: 32.7 ± 9.5%, RMNPI: 19.7 ± 9.5%, RMNPI-Bretz: 30.2 ± 9.9; p ≤ 0.001 each). However, Bland-Altman analysis revealed distinct systematic and proportional biases in relation to P%. As P% was not linearly related to the index values, equations were derived, enabling the conversion into actual plaque coverage. Those were applied to T-QHPI and RMNPI data from the literature to allow a deeper understanding of effect sizes.
Plaque indices only partially reflect actual plaque coverage. Compared to RMNPI, T-QHPI and RMNPI-Bretz gave closer agreement with the planimetric measurements. These findings highlight the limitations of traditional plaque indices in accurately representing plaque reduction, while offering a new approach to enhance the interpretability of oral hygiene studies.
临床菌斑指数是用于量化菌斑控制效果的成熟方法，例如，用于评估不同类型牙刷的效果。然而，此类研究中观察到的效应大小取决于所使用的指数。因此，本研究旨在评估Turesky改良的Quigley-Hein菌斑指数（T-QHPI）、Rustogi改良的海军菌斑指数（RMNPI）以及Bretz改良的RMNPI（RMNPI-Bretz）评分与实际菌斑量的对应关系。
纳入30名年龄在24.0±4.1岁的参与者。在72小时不进行口腔卫生护理后，以及随后进行习惯性刷牙后，使用口腔内扫描仪（Carestream 3800）采集使用显影剂（Mira-2-Ton®）后的菌斑图像。将与各指数对应的评分网格投影到Ramfjord牙（16、21、24、36、41和44）口腔侧和前庭侧的标准化图像上并进行评分。之后，通过面积测量法定量实际菌斑覆盖率（P%）。
所有方法在刷牙后均使菌斑显著减少（P%：42.1±14.0%，T-QHPI：32.7±9.5%，RMNPI：19.7±9.5%，RMNPI-Bretz：30.2±9.9；各p≤0.001）。然而，Bland-Altman分析显示，与P%相关存在明显的系统偏差和比例偏差。由于P%与指数值并非线性相关，因此推导了相关方程，可将其转换为实际菌斑覆盖率。这些方程应用于文献中的T-QHPI和RMNPI数据，以便更深入地理解效应大小。
菌斑指数仅部分反映实际菌斑覆盖率。与RMNPI相比，T-QHPI和RMNPI-Bretz与面积测量法的测量结果更为一致。这些发现凸显了传统菌斑指数在准确表示菌斑减少方面的局限性，同时提供了一种新方法来提高口腔卫生研究的可解释性。
