Hygienic maintenance of the interdental space is encouraged to prevent periodontal diseases [21, 22]. With the help of 3D printing technology, it was possible to quantify the cleaning efficacy of the interdental brush on the embrasure surfaces of the teeth. Most notably, while the cleaning efficacy was positively correlated with the number of washes, a plateau was obtained starting from the 5th cycle. Moreover, it was confirmed that there was a positive correlation between the diameter of the IDBs and cleaning efficacy. This evidence supported the previous article’s claim that the size and specifications of oral hygiene aids such as IDBs should be accurately selected [19, 23]. Herein, the plateau obtained after the 5th washing cycle shows the same tendency in other studies . Contrary to some prior research that showed that the cleaning effect was greater as the number of cleaning cycles increased, the results of this study could be a guideline for practical use. Repeated cleaning does not need to be for more than five cycles because there is a higher risk of interdental gingival (papillary) bleeding, which can add to adverse effects in addition to the cleaning .
It is recommended to use an IDB with a diameter larger than the size of the interdental space . In this study, IDB of a size greater than the given embrasure gave the optimal performance diameters of 1.2 and 1.5 mm at 0.7 and 1.2 mm embrasures, respectively. A previous study presented the 10th cycle on the molar using dental floss, holder-type dental floss, and IDBs (size SSS) and observed the mesial side . In this study, the cleaning efficacy was shown in the order of floss (53%), IDBs (46%), and floss holder (28%), but since the embrasure size was not specified, it was somewhat difficult to interpret this as a quantitative experimental result. Meanwhile, dental experts suggest using IDBs of sizes that are slightly larger than the patient's embrasure size, and this study supports the experts’ hypotheses. This is thought to be because the toothbrush has to be longer than the actual diameter to penetrate deeper as the shape of the actual tooth is concave. The cleaning efficacy of an IDB is influenced by the design and diameter of the IDB, and the size of the interdental space [19, 25]. Therefore, further studies are needed on the effect of these factors like varying diameters and shapes of IDBs on cleaning efficacy.
Additionally, in this study, the experiments were conducted with interdental space and various embrasure sizes that were customized in proportion to the actual human physique. In previous clinical research, patients were made to use IDBs for three months to compare the effectiveness of conically shaped and cylindrically shaped IDBs; and plaque scores, bleeding upon pocket probing scores, and probing pocket depth were assessed . Though the patients were educated by specialists who worked on the experiments, apparently, the reproducibility was reduced for each patient. Furthermore, there was the limitation that the evaluation criteria lacked objectivity. 3D printing technology is widely adopted in the field of dentistry, for example, crowns, bridges, reconstructors, splints, and implants . Previous research investigated the high accuracy of 3D-printed teeth . However, to the best of our knowledge, there is no study focused on evaluation of the IDBs in different sizes using the 3D-print model. However, there was a study that tested cylindrical IDBs (0.8, 0.9, 1.2, and 1.4 mm) and interdental tooth surfaces constructed by a 3D printer based on human teeth and matched to morphologically equivalent pairs, such as the isosceles triangle, concave and convex fitting to the different gap sizes (1.0, 1.1, and 1.3 mm) . In an isosceles triangle with a 1 mm gap, IDBs with a 0.9 mm diameter showed the highest cleaning efficiency at 84%. Thus, IDBs can be tested by a new experimental setup supported by 3D printing technology. Moreover, it is possible to conduct more direct and definite experiments through 3D printing by designing various human interdental spaces and embrasures with CAD software. This study will serve as a benchmark for conducting experiments by grafting not only IDBs but also various oral products.
This testification provides an example of the delicate modeling and manufacturing of such anatomical 3D architecture performed expeditiously and conveniently. The current model provides a fundamental solution to and suggestion for one of the largest unmet needs of patients and practitioners systemically. However, there are many limitations to our study. First, actual dental plaque is different from an artificial plaque in its characteristics. Second, there are differences between the 3D-printed oral structure and the actual biometric oral structure. Third, cleaning efficacy according to the shape of the IDB was not considered. However, the basic research was conducted; and the observation of quantitative measures on cleaning efficiency was attempted [10, 27]. As the shape of the IDB affects the cleaning efficacy, additional research must identify its correlation with various IDB specifications.