Mapping dental biofilms : from plaque index through planimetry to volumetric analysis

Povšič, Katja (author), Fijavž, Luka (author), Munjaković, Haris (author), Kašaj, Adrian (author), Gašperšič, Rok (author)

Objectives Conventional plaque assessment methods, such as clinical indices and planimetry, rely on plaque-disclosing agents and may overemphasize thin biofilm areas due to plaque thickness variations. This study introduces a digital 3D method to quantify and visualize dental plaque volume from consecutive intraoral scans (IOS) and compares it with the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPlI) and planimetry. Methods After professional supragingival debridement at baseline (T0), fifteen participants refrained from oral hygiene for four days (T4). De novo plaque formation was assessed at T4 using TMQHPlI after application of a two-tone (pink/purple) plaque-disclosing agent. IOSs (3Shape TRIOS 4) were obtained at T0 and T4. Plaque accumulation was quantified using color-coded IOS comparisons with the Volumetric Plaque Index (VPI) and Adjusted VPI (AVPI). Machine learning (Trainable Weka Segmentation) was used to calculate the Planimetric Plaque Index (PPI). Results A correlation between plaque surface area and volume was observed only for purple/mature plaque (p = 0.043). Early plaque growth was dominated by expansion of pink-stained, newly formed plaque. Once more than one-third of the surface was covered, further increases resulted mainly from vertical thickening rather than lateral spread. Conclusions 3D volumetric analysis offers a comprehensive, objective, and clinician-friendly method for assessing dental biofilms. Clinical relevance The proposed 3D approach enables accurate monitoring of plaque accumulation and maturation, improving personalized oral hygiene assessment, patient education, and clinical decision-making.

• Language: English
• Keywords: 3D imaging, computer assisted image analysis, dental deposits, dental plaque, dental plaque index, diagnostic imaging
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 10 str.
• Numbering: Vol. 30, iss. 1, art. 38
• PID: 20.500.12556/RUL-179009
• UDC: 616.31
• ISSN on article: 1432-6981
• DOI: 10.1007/s00784-025-06729-z
• COBISS.SI-ID: 266182915
• Publication date in RUL: 03.02.2026

Record is a part of a journal

• Title: Clinical oral investigations
• Shortened title: Clin. oral investig.
• Publisher: Springer Nature
• ISSN: 1432-6981
• COBISS.SI-ID: 1737748

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: 3D slikanje, računalniško podprta analiza slik, zobne obloge, indeks zobnih oblog, diagnostično slikanje

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P3-0293
• Name: Parodontalna medicina