L.S.T.R. is a specialized therapeutic concept and non-instrumental (or minimal-instrumentation) endodontic approach used primarily in pediatric dentistry to treat grossly decayed or non-vital primary (deciduous) teeth.

Core Concept & Mechanism

The "Leave and Sterilize" Principle: Unlike conventional root canal therapy or pulpectomies that require extensive mechanical filing and shaping of root canals, L.S.T.R. relies on chemical sterilization to eliminate bacteria from infected root dentin and periapical areas.

Triple Antibiotic Paste (3-Mix): The treatment centers around the application of a specialized antibacterial mix—commonly comprising Ciprofloxacin, Metronidazole, and Minocycline (or Clindamycin)—blended with a vehicle like propylene glycol or macrogol (MP paste).

Tissue Healing: By successfully sterilizing deep-seated lesions and dentinal tubules that conventional instruments cannot reach, the body's natural defense mechanisms are allowed to repair and regenerate the surrounding tissues.

Main Clinical Indications

Infected Primary Molars: Employed when primary teeth exhibit deep carious lesions with pulp involvement or mild periradicular pathosis.

Alternative to Extractions: Used to preserve baby teeth that might otherwise require extraction or complex instrumentation, helping maintain arch space for permanent successors.

Non-Negotiable Canals: Useful in cases where root canals are tortuous, calcified, or difficult for a young patient to tolerate via traditional lengthy endodontic procedures.

Key Advantages

Minimally Invasive: Significantly reduces chair time and avoids aggressive mechanical filing, making it ideal for pediatric patients.

Broad-Spectrum Efficacy: Combines multiple drugs to simultaneously target a wide range of aerobic and anaerobic bacteria found in deep root infections.