Can a Simple Sheet of Plastic Keep You Safe?
Research from the University of North Sumatra reveals how plastic wrapping dramatically reduces bacterial contamination on dental surfaces
You lean back in the sleek, modern dental chair. The light shines brightly, and the dentist's tools are laid out neatly on a smooth, stainless-steel work desk. It looks clean, sterile, and professional. But what if we told you that this very surface, touched repeatedly by gloved hands and potentially exposed to aerosols from your mouth, could be a bustling metropolis for invisible bacteria? The Department of Oral and Maxillofacial Surgery at the University of North Sumatra (USU) set out to answer a critical question: in the ongoing battle for clinical hygiene, does a simple, low-cost solution—plastic wrapping—actually make a difference?
Every surface in a healthcare setting, no matter how clean it looks, harbors microorganisms. In a dental clinic, these can include bacteria from a patient's oral cavity, which are aerosolized during procedures like drilling, or transferred via contaminated gloves and instruments.
While rigorous cleaning protocols exist, the time between patients is short. Disinfectants need "contact time" to work effectively, and in a busy clinic, that time is a luxury. This is where barrier protection comes in. The theory is simple: instead of constantly disinfecting the surface itself, you cover it with a physical barrier that you replace after each patient. It's like putting a fresh tablecloth on a table for every new guest.
Researchers at USU's Faculty of Dentistry designed a straightforward yet powerful experiment to measure the effectiveness of this approach right in their own Department of Oral and Maxillofacial Surgery.
The study was conducted in the actual operating environment of the department, ensuring real-world conditions.
Dental units were divided into two groups: a control group with standard disinfection and an intervention group with plastic wrapping.
Researchers used swab sampling to collect bacteria from defined areas of the work desks after each patient procedure.
Each swab was streaked onto Blood Agar plates, a nutrient-rich medium that encourages bacterial growth.
After incubation, researchers counted the Colony Forming Units (CFUs) on each plate to measure contamination levels.
Statistical analysis compared bacterial counts between the two groups to determine effectiveness.
Work desks cleaned with standard hospital-grade disinfectant (70% isopropyl alcohol) according to normal protocol between patients.
Work desks tightly covered with transparent plastic wrap that was replaced after each patient procedure.
Swab sampling from defined areas to collect bacteria, which were then cultured and counted as Colony Forming Units (CFUs).
The results were striking. The dental units where the work desks were covered with plastic wrap showed a dramatically lower number of bacterial colonies compared to those that were only disinfected.
What does this mean? The plastic wrap created a highly effective physical barrier. While the disinfection process reduces microbes, it is not always 100% effective in the short time available and can be applied inconsistently. The plastic wrap, however, is removed and replaced, physically carrying away all the contaminants from the previous patient.
| Group | Common Bacteria Found |
|---|---|
| Control (Disinfection) | Staphylococcus spp. Bacillus spp. Micrococcus spp. |
| Intervention (Plastic Wrap) | Primarily low-level environmental contaminants or none |
This research relies on a few fundamental tools and materials. Here's a breakdown of the essential "research reagents and solutions" used in this field.
The collection device. They are sterilized to ensure no external bacteria contaminate the sample during collection.
The growth medium. This gel-like substance contains nutrients and sheep blood, providing a rich environment for a wide variety of bacteria to grow.
A temperature-controlled oven. It maintains an optimal temperature (usually 37°C, human body temperature) to encourage rapid bacterial growth.
The standard disinfectant. It works by denaturing the proteins in bacterial cells, effectively killing them. 70% is used instead of 100% because it penetrates cells more effectively.
The physical barrier. It is impermeable to bacteria and fluids, inexpensive, and easy to apply and remove, making it an ideal single-use shield.
Advanced laboratory techniques were used to identify bacterial species and perform statistical analysis on the collected data.
The evidence from the University of North Sumatra is clear and compelling. The simple act of wrapping dental unit work surfaces in plastic—and changing it meticulously between every patient—is a remarkably effective strategy for minimizing bacterial contamination. It acts as a foolproof, low-cost insurance policy, complementing standard disinfection protocols.
This research highlights a powerful principle in infection control: sometimes, the most elegant solution is not a stronger chemical, but a smarter physical barrier. The next time you're in a dental chair, you might just spot that thin layer of plastic. It's a silent guardian in the invisible war for your health, proving that in the world of science, even the simplest ideas can have a profound impact.
Reference: Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of North Sumatra (USU). The effectiveness of the use of plastic wrapping on dental unit work desks on the number of bacterial colonies.