OralDisk: A Chair-Side Compatible Molecular Platform Using Whole Saliva for Monitoring Oral Health at the Dental Practice

Abstract

Periodontitis and dental caries are two major bacterially induced, non-communicable diseases that cause the deterioration of oral health, with implications in patients’ general health. Early, precise diagnosis and personalized monitoring are essential for the efficient prevention and management of these diseases. Here, we present a disk-shaped microfluidic platform (OralDisk) compatible with chair-side use that enables analysis of non-invasively collected whole saliva samples and molecular-based detection of ten bacteria: seven periodontitis-associated (Aggregatibacter actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola) and three caries-associated (oral Lactobacilli, Streptococcus mutans, Streptococcus sobrinus). Each OralDisk test required 400 µL of homogenized whole saliva. The automated workflow included bacterial DNA extraction, purification and hydrolysis probe real-time PCR detection of the target pathogens. All reagents were pre-stored within the disk and sample-to-answer processing took < 3 h using a compact, customized processing device. A technical feasibility study (25 OralDisks) was conducted using samples from healthy, periodontitis and caries patients. The comparison of the OralDisk with a lab-based reference method revealed a ~90% agreement amongst targets detected as positive and negative. This shows the OralDisk’s potential and suitability for inclusion in larger prospective implementation studies in dental care settings.

ImmunoDisk—A Fully Automated Bead-Based Immunoassay Cartridge with All Reagents Pre-Stored

“…Lyophilization or freeze-drying is often used to store proteins (alone, i.e., without beads) due to the good stabilization achieved with this method, even though it is costly and technologically complex [ 61 ]. Concerning beads alone, we have demonstrated protocols for pre-storage in the case of magnetic beads for nucleic acid extraction and purification [ 62 , 63 , 64 ]. However, the BFPD-IA that is integrated within the ImmunoDisk involves protein-coupled magnetic and fluorescent beads.…”

“…These conditions simplify the fluidic integration and reduce the footprint on disk. Importantly, the ImmunoDisk was processed on a device, the LabDisk Player 1 functional model, which was developed for the automation of nucleic acid amplification technologies (NAATs, e.g., PCR and isothermal methods) and for which different applications have already been shown (e.g., respiratory tract infections [ 64 ], tropical infections [ 63 ], oral diseases [ 62 ] and vector analysis in mosquitos [ 76 ]), without any changes to the device hardware. The compatibility of the ImmunoDisk with this NAAT device is primarily due to the protocol and the detection principle of the BFPD-IA, as well as the adaptation of the microfluidic structures.…”

Clinical laboratory diagnostics in dentistry: Application of microbiological methods

“…These molecular platforms enable a very rapid sampling-to-answer pipeline (i.e., within a patient session). Chair-side assays under development include molecular quantification of periodontal or cariogenic species [ 40 – 42 ] or the detection of antibiotic resistance genes [ 43 ] within oral samples.…”

Salivary biomarkers as key to monitor personalized oral healthcare and precision dentistry: A scoping review

“…Aside, it seems crucial to control and detect individuals' deviations of the oral health status at an early stage to hinder disease outbreak. While gold standard clinical examinations and radiographs at the dental office may miss developing disorders on a cellular base, other diagnostic tools and modern technical possibilities gain more importance ( 4 , 5 ). Different biofluids, such as periphery blood, gingival crevicular fluid (GCF), and saliva were evaluated for their diagnostic or prognostic qualification for disease detection ( 6 ).…”

“…It was shown, that the oral microbiome can be quantified to a certain extent in saliva ( 9 , 10 ), and even more interesting, host immune response to pathogens can be analyzed nearly in real-time ( 11 ). Furthermore, modern technologies allow the detection and quantification of specific substances in low concentrations ( 4 , 12 ). Today, improvements and further developments in point-of-care devices evolve from technical progress in the era of Covid 19 ( 13 , 14 ).…”