Diode Laser-Guided Protocol for Endo-Perio Lesions: Toward a Multi-Stage Therapeutic Strategy—A Case Series and Brief Literature Review

Background and Objectives: This prospective case series evaluated a treatment strategy in endodontic-periodontal lesions resulting from concurrent pulpal and periodontal infections. These present significant management challenges, particularly when they exhibit resistance to standard treatment modalities. Persistent microbial biofilms in regions like dentinal tubules and lateral canals can make it hard for healing to happen, even with good endodontic and periodontal care. Diode lasers have antibacterial and photobiomodulatory effects, but they are most often used as single-stage disinfection techniques. This pilot study evaluated a multi-stage diode laser protocol designed to enhance healing outcomes in refractory endo-perio lesions that had not responded to conventional treatment. Materials and Methods: Twelve patients (aged 20–60 years) with chronic endo-perio lesions, referred after unsuccessful earlier treatment, were treated utilizing a sequential diode laser regimen: Phase 1—Endodontic disinfection: Following canal instrumentation (0.75 W, pulsed mode, frequency 15 Hz, 200 μm fiber, 15 J dosage/20 s) using a 976 nm diode laser. Phase 2—Periodontal disinfection: Following SRP, intra-pocket (0.75 W, pulsed mode, frequency 15 Hz, 300 μm fiber, 3.75 J dosage/5 s) using a 976 nm diode laser; Phase 3—Post treatment photobiomodulation: After periodontal and endodontic therapy, photobiomodulation was applied using a 650 nm diode laser intra-pocket and in the periapical region (25 mW, continuous mode, 1.5 J dosage) to reduce postoperative inflammation and stimulate healing. Clinical parameters—probing depth (PD), bleeding on probing (BOP), and mobility—along with radiographic bone fill were recorded at baseline and after 6 months. Results: All twelve cases showed measurable within-patient improvements over the six-month follow-up. Median probing depth decreased from 7.6 mm to 6.0 mm, and median bleeding on probing declined from 0.9 to 0.3. Radiographically, partial bone fill was observed in all cases, with a median value of 58.3 percent. Postoperative pain decreased progressively over the first 24 h, with patients reporting mild discomfort by 24 h. No adverse events were recorded. Conclusions: Within the limitations of this small, uncontrolled pilot study, the multi-stage diode laser protocol was associated with clinical and radiographic improvements and low postoperative discomfort in refractory endo-perio lesions. These preliminary findings suggest that such a protocol may serve as a useful adjunct to conventional therapy. Larger, controlled studies are required to confirm these outcomes and determine long-term efficacy.