## 4 Discussion
Unlike broad-spectrum antimicrobials that may disrupt beneficial microbiota, ALA-based PDT offers a focused intervention with fewer collateral effects [32; 33; 34; 46]. For example, an ex vivo study on permanent teeth showed bacterial reduction comparable to 2.5% sodium hypochlorite in eliminating _E. faecalis_[27]. By leveraging the selective susceptibility of bacterial cells to photodynamic effects, ALA-based PDT not only eliminates pathogens but also promotes tissue healing and regeneration--especially valuable in pediatric care. In pediatric dentistry, this selective approach is crucial. While sodium hypochlorite remains a common irrigant, it has drawbacks: unpleasant taste and odor, inconsistent disinfection, and potential toxicity if extruded into periadicular tissues. It can also harm structures like permanent tooth follicles, peripheral tissues, and oral mucosa if not carefully managed [47]. ALA-based PDT offers a safer, targeted alternative that preserves the surrounding tissue while ensuring effective microbial decontamination--an ideal solution for pediatric endodontic infections. In addition to its antimicrobial properties, ALA-based PDT presents promising applications for pediatric dentistry, especially in supporting patient-centered care and optimized treatment strategies [48; 49; 50]. Given the non-invasive nature of PDT and its low risk of adverse effects, it offers a compelling therapeutic option for young patients who may experience anxiety with conventional endodontic treatments. By introducing a less invasive and more comfortable alternative to standard antimicrobial therapies, ALA-based PDT can potentially improve patient compliance, decrease treatment-related stress, and make dental visits more positive for children. Notably, future research should explore how laser-assisted PDT might influence pediatric behavioral management, as this could further enhance its viability in clinical practice [51]. However, ALA-based PDT does come with certain limitations that require careful consideration. One critical factor is the effective delivery and penetration of light within the root canal system to ensure thorough microbial eradication. The complex morphology of root canals, especially in primary teeth with underdeveloped roots, can hinder uniform light distribution and tissue penetration [10]. This anatomical complexity may reduce the treatment's efficacy unless these challenges are addressed. Future innovations in light delivery systems, potentially tailored to the specific anatomical features of pediatric patients, may help overcome these issues and improve clinical outcomes [27]. Custom treatment protocols that account for unique pediatric dental anatomy may be essential to fully realize the benefits of ALA-based PDT in young patients. An important aspect to consider is the timing and integration of PDT within the overall endodontic treatment protocol. While PDT provides rapid microbial decontamination and several adjunctive benefits, successful clinical application requires thoughtful alignment with existing treatment processes. Clinicians must carefully weigh factors such as session duration, pre-irradiation time, and post-treatment care to maximize the therapeutic potential of ALA-based PDT while avoiding unnecessary disruptions or delays. Though PDT is less invasive and simpler than full endodontic treatment [10], the 45 min gel application within the canal system may be challenging for pediatric patients with limited chair tolerance. By comparing two patient groups--one undergoing a single extended session (Group A) and another receiving a temporary filling with the option to leave immediately after gel placement (Group B)--we were able to evaluate the practical implications of each approach. This comparison highlights the flexibility of PDT protocols and the potential benefits of adapting treatment timing to patient needs, especially in pediatric dentistry where cooperation can vary significantly.