Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola—collectively known as the red complex periodontopathogens—have been widely analyzed in clinical samples from individuals with periodontitis. A lab-on-a-chip (LOC) is a compact device that consolidates multiple laboratory processes onto a single microchip or small platform. This systematic review investigates the utilization of LOC technology for detecting microorganisms within the red complex. The study followed PRISMA guidelines and involved searches across multiple databases. From 58 initially retrieved records, 10 met the inclusion criteria. All selected studies reported efficient, rapid, and accurate LOC systems capable of detecting and amplifying P. gingivalis, T. forsythia, and T. denticola. When compared with conventional methods, LOC-based detection required substantially fewer reagents. Moreover, amplification was achieved within approximately 2–8 minutes, and detection within about 2 minutes and 40 seconds, resulting in a total experimental time of roughly 11 minutes. The combination of miniaturization, precision, automation, and speed highlights LOC platforms as promising tools for the identification and amplification of red complex bacteria implicated in periodontal diseases.
