Preliminary Investigation of the Usefulness of Oral Hygiene Assessment Using an Intraoral Scanner

<p>Background : Intraoral scanners (IOS) are capable of acquiring three-dimensional color images of the teeth. Therefore, the detection of areas with plaque adhesion stained by plaque-disclosing solutions using an IOS could potentially serve as a method for evaluating oral hygiene. This study aimed to assess the utility of obtaining O'Leary's plaque control record (PCR)measurements using an IOS in clinical practice.</p><p>Methods : Eight patients were included in the study. Plaque was stained with gel, and PCR values were assessed visually using the 6-point method with O'Leary's PCR. Subsequently, the teeth were scanned using an IOS, and digital images were recorded. PCR values were measured again from the IOS images displayed on a monitor. Following the PCR measurement, oral hygiene instructions were provided to the patients based on the IOS images on the monitor. After the maintenance procedure, patients were asked to complete a questionnaire regarding their discomfort level with IOS imaging and their understanding of plaque staining sites. The evaluation was conducted by comparing the PCR values measured visually and those obtained from the IOS images. The questionnaire was also used to evaluate discomfort during IOS imaging and the ability to identify plaque-stained areas on the labial and palatal sides of the anterior teeth as well as on the buccal and lingual sides of the molars.</p><p>Results : Red-stained dental plaque was visible in the IOS images, also revealing restorative steps, thin stained areas, and staining of the cervical area. The captured IOS images could be rotated and magnified to confirm the tooth surfaces on the palatal and center surfaces, which can be challenging to discern through visual inspection. Generally, the PCR values derived from the IOS images were higher than those obtained by visual examination. Furthermore, the questionnaire results indicated that the discomfort experienced during IOS imaging was comparable to that during intraoral examination. Patients displayed a good level of comprehension of the IOS imaging.</p><p>Conclusion : These results demonstrate the utility of IOS in assessing oral hygiene. Nevertheless, certain challenges persist, including the difficulty of inserting the IOS tip when acquiring images of the most posterior molars in cases with limited mouth opening and issues related to the reflection of gingival color on the surfaces of all-metallic crowns. We aim to employ the oral hygiene instruction evaluation method using IOS across a range of cases in the future to further validate its effectiveness.</p>