Endodontic Microtargeting—An Innovative Intelligent Minimally Invasive Approach for Canal Disinfection

This letter introduces a new concept in root canal disinfection that aligns with the shift toward minimally invasive and biologically informed practice in root canal treatment: endodontic microtargeting.This proposal advocates for the development and implementation of precision-guided, intelligent systems specifically designed to target anatomically complex root canal systems with customized antimicrobial delivery devices.This approach transcends traditional bulk irrigation techniques and instrument-centric cleaning methods that may not effectively access intricate canal systems.It is well known that mechanical canal instrumentation does not adequately debride complex canal systems. 1 This is particularly true in challenging regions such as flattened oval canals, lateral canals, apical deltas, and isthmi, where infection persists despite conventional cleaning techniques. 1 While various irrigant activation techniques have been developed to enhance antimicrobial efficacy, these methods still lack the precision required to specifically target zones of potential infection.2,3 The pressing clinical need is to develop systems that are capable of dynamically detecting, navigating, and acting upon localized infections within the root canal system.By leveraging significant advances in fields like oncology and nanomedicine, 4,5 the potential of smart delivery systems can be explored in the context of canal disinfection.These systems could utilize pH-responsive or enzyme-activated nanocarriers designed to transport and release disinfectants in a controlled manner in response to microbial signals or under low-pH biofilm conditions, 4,5 serving as complementary therapies to conventional debridement strategies.Smart delivery systems integrate targeted carrier mechanisms, active navigation, stimuli-responsive release, and closed-loop sensing with feedback to deliver therapeutic agents with precision.In medicine, these strategies are wellestablished: nanoscale carriers, including liposomes, polymeric nanoparticles, and magnetic nanoparticles (MNPs), can be directed to specific tissues and release drugs in response to local chemical cues or external stimuli (e.g., pH, temperature, enzymes, magnetic fields).[4][5][6] Additionally, advancements in micro-robotics and biohybrid microcarriers are paving the way for vehicles that actively navigate body fluids and deliver therapeutic cargo to difficult-to-access regions.[6][7][8] The MNPs exemplify this approach, enabling targeted drug delivery to lesions through externally applied fields and facilitating on-demand release.9 Furthermore, stimuli-responsive nanoparticles that are sensitive to microenvironmental variations-such as acidic pH, redox conditions, or specific enzymes-enable the release of antimicrobials exclusively at infected sites, thereby enhancing therapeutic efficacy and minimizing off-target effects.10 Applying these principles to endodontics reveals several promising smart-delivery strategies for microtargeting within the root canal systems:• Functionalized Nanoparticles as Guided Payloads: Antimicrobial and bioactive agents can be encapsu- lated within nanoparticles, enhancing their penetration into dentinal tubules compared to traditional bulk irrigants.These nanoparticles can be surface-functionalized to improve affinity for tubule walls or to respond to bacterial enzymes for targeted release.For instance, silver and chitosan nanoparticles have demonstrated in vitro antimicrobial activity in endodontic applications and could be adapted into stimuliresponsive carriers.