Abstract
BACKGROUND: The long-term success of endodontic treatment is significantly influenced by the sealing ability of the obturation technique used to prevent microbial leakage. Various obturation techniques aim to achieve an impervious seal, but the efficacy of these techniques in preventing microbial penetration remains controversial. MATERIALS AND METHODS: Sixty extracted single-rooted human mandibular premolars were decoronated and prepared using the ProTaper Universal rotary system. Teeth were randomly assigned into three groups (n = 20 each): Group 1 - CLC; Group 2 - WVC; Group 3 - TIGP. After obturation and coronal sealing, specimens were subjected to a dual-chamber microbial leakage model using Enterococcus faecalis. Turbidity in the lower chamber indicated leakage. The observation period was 60 days, and data were analyzed using Kaplan-Meier survival analysis and Chi-square test. RESULTS: TIGP exhibited the least microbial leakage (mean leakage time = 49.8 ± 5.3 days), followed by WVC (44.3 ± 6.7 days), and CLC (32.5 ± 7.9 days). The differences were statistically significant (P < 0.01). By the end of the test period, leakage occurred in 85% of CLC, 60% of WVC, and 30% of TIGP samples. CONCLUSION: Thermoplasticized injectable gutta-percha showed superior resistance to microbial leakage compared to cold lateral and warm vertical compaction techniques. These findings support its use in clinical practice to enhance the longevity of root canal treatments.