Panoramic radiography is generally regarded as a routine and safe procedure. The patient sits down, places their chin on the support, the machine rotates around the head, and the examination is complete. Yet behind this seemingly simple procedure, subtle chemical reactions occur in the soft tissues of the oral cavity—reactions that cannot be seen or felt but can be measured.
Dr. drg. Rurie Ratna Shantiningsih, MDSc, from the Department of Dental Radiology, Faculty of Dentistry, Universitas Gadjah Mada, has long been interested in this question. Together with her research team, she developed a simple yet innovative approach: a beta-carotene mucoadhesive patch applied to the gingiva before patients undergo panoramic radiographic exposure.
Gingiva That Responds to Radiation
Gingival crevicular fluid (GCF) is an exudate secreted from the gingival mucosa, the tissue surrounding the neck of the tooth. Its volume can provide an indication of the condition of the tissues surrounding the teeth. When irritation or inflammation occurs, GCF volume increases as capillary permeability in the gingival tissues rises.
Although panoramic X-ray exposure involves a relatively low dose, it can trigger this response. Previous studies have shown that radiation from panoramic radiography can damage cells through oxidative reactions, including the formation of micronuclei as markers of chromosomal damage and the expression of 8-oxo-dG, a biomarker of oxidative DNA damage.
This raised an important question: could such damage be prevented, or at least reduced?
A Yellow Patch Behind the Smile
The study involved 20 subjects who required panoramic radiographic examinations. Before exposure, participants in the intervention group received a beta-carotene mucoadhesive patch applied to the gingival mucosa around teeth 11 and 21—the upper right and left central incisors. The control group underwent the same procedure without the patch. Five minutes after exposure, GCF was collected from the labial surfaces of both teeth using sterile filter paper.
GCF volume was measured by applying 2% ninhydrin solution to the filter paper. The resulting purple color was measured using a digital caliper. Meanwhile, 8-oxo-dG levels were measured using an Enzyme-Linked Immunosorbent Assay (ELISA), a technique capable of quantitatively detecting DNA damage biomarkers.
The results were notable. The group using the beta-carotene patch demonstrated significantly lower GCF volume than the control group (p < 0.05). The 8-oxo-dG level was also lower, with a mean of 0.767 ± 0.368 in the intervention group compared with 1.082 ± 0.547 in the control group, with the difference also reaching statistical significance (p = 0.036).
“A beta-carotene mucoadhesive gingival patch may be recommended to prevent the effects of panoramic radiographic exposure on GCF.” — Dr. drg. Rurie Ratna Shantiningsih, MDSc
How Beta-Carotene Works in Gingival Tissue
Beta-carotene is more than the orange pigment found in carrots. In cellular biology, it has potential antioxidant properties. In this study, its mechanism was described through two main pathways.
First, beta-carotene may suppress the accumulation of reactive oxygen species (ROS), reactive oxygen molecules that are major triggers of DNA damage and inflammatory responses. Suppressing ROS may also inhibit the activation of NF-κB, a protein involved in the expression of inflammatory genes. Second, from a physicochemical perspective, the patch may neutralize singlet oxygen and enhance intercellular communication through increased expression of connexin-43 markers.
In other words, the patch does not merely function as a physical barrier. It also acts as an active chemical shield at the molecular level.
From the ALARA Principle to Clinical Innovation
In dental radiology, the ALARA (As Low As Reasonably Achievable) principle serves as a fundamental guideline: radiation exposure should be kept as low as reasonably achievable. Lead aprons, beam collimation, and careful selection of examination indications are all part of this principle.
The beta-carotene patch offers an additional protective layer, particularly for the soft tissues of the oral cavity, which may not always be adequately protected by conventional protective equipment. The study builds upon a series of previous investigations that examined the effectiveness of similar patches in New Zealand rabbit models and now provides additional clinical evidence in humans.
Interestingly, the material itself is not exotic. Beta-carotene is readily available, relatively inexpensive, and generally considered safe for biological tissues. The next challenge is to optimize its formulation, dosage, and application method so that it can be practically adopted in dental clinics.
Every time a patient sits in the radiology chair and the panoramic machine begins rotating, thousands of chemical reactions occur within seconds in the soft tissues of the oral cavity. Research such as this reminds us that the best protection does not always come in the form of a large shield. Sometimes, it may come from a small yellow patch quietly adhering to the gingiva.
Source DOI: https://doi.org/10.1063/1.5098429
Authors: Anny Anggraini; drg. Achmad Zam Zam Aghasy, M.Kes.
Photo: Pexels