Currently, monitoring oral health relies mainly on the visual examination of the oral tissues
aided electively by radiographic or photographic images. In the context of oral health,
monitoring involves detecting changes, sometimes rather subtle, in the soft or hard oral
tissues.
The slow rate of change involved in some situations, like loss of mineral tissues due to
caries or tooth wear, makes it extremely difficult for the human eye alone to identify them.
It is even more challenging to accurately register and recall the original situation on the
patient's follow-up visits. Clinical photographs are therefore used to aid the monitoring
however, it is difficult to obtain comparable photographs from different points in time and
the subjectivity involved in the process cannot be avoided.
Different criteria are used in clinical practice to register and monitor changes in the oral
tissues, according to the specific condition under investigation. While identifying
significant changes is an easy task, the challenge lies particularly in identifying early,
incremental changes. Regarding the detection of caries lesions, a number of initial lesions
typically remain unnoticed when visual examination alone is used; or even when radiographs
are employed, as the latter are not sensitive to early demineralization in enamel. Concerning
tooth wear (i.e. erosion, abrasion, attrition), as the gradual mineral loss occurs
progressively and irreversibly, it is usually only noticed when a significant amount of hard
dental tissue is already lost.
A promising clinical solution to overcome the challenges involved in the detection of early
changes and monitoring of oral tissues is the use of 3D intraoral scans. Obtaining 3D scans
directly from the patients (in vivo) using intraoral scanners and by comparing 3D scans
obtained from the same patients at different points in time, a less subjective and more
reliable comparison of data is expected: the 3D scans can be overlapped and analyzed using
specific software. Therefore, it is hypothesized that 3D intraoral scans can be used for more
consistent monitoring of oral health in relation to clinical photographs or clinical records.
The current 3D intraoral scanners capture the color of the oral tissues by emitting visible
white light. A recently developed 3D intraoral scanner manufactured by 3Shape A/S, Denmark,
is also able to emit visible blue light (415 nm wavelength) that allows capturing
fluorescence from the oral tissues. Fluorescence is one of the most promising technologies
for accurate detection of the early stages of enamel demineralization, but is currently
available only in 1D or 2D devices. The main limitation of the existing devices featuring
fluorescence, as already mentioned, is the challenge in comparing single images obtained at
different points in time, which is at large influenced by imaging artifacts and noise.
Imprecision in the comparison of these images compromises the ability to accurately monitor
progressive demineralization of the dental hard tissues. There is no intraoral scanner
reported in the scientific literature that combines fluorescence with 3D imaging. Thus, the
investigators hypothesize that this new intraoral scanner will benefit the monitoring of
dental hard tissues and will aid dentists to identify early changes in tissue mineralization.
With this method it is only possible to examine the tooth surfaces that are visible and
directly exposed into the mouth (i.e. the smooth free surfaces and the occlusal fissures);
the areas between the teeth (i.e. the approximal surfaces) cannot be visualized and therefore
cannot be examined using the scanner.
A total number of 70 participants will be recruited for the study, including adolescents and
young adults (12-19 years old). The oral health of all participants will be examined using
visual-tactile and radiographic methods. Subsequently, both the upper and lower jaw of the
participants will be scanned using the intraoral scanner (TRIOS 4, 3Shape TRIOS A/S,
Denmark). All participants will be monitored for 1 year with follow-up intervals of 3 to 12
months according to the risk group that they are classified into (low, moderate, high). The
same clinical procedures will be followed on the follow-up examinations (3 or 6 months) as
well as on the final examination (1-year follow-up) The clinical registrations from oral
examination using the state-of-the-art methods (visual-tactile, radiographic) will be
compared with the outcomes from the assessment using the intraoral scanner.