This study is designed to compare two commonly used methods for measuring the length of the root canal during root canal treatment. Accurate measurement of the root canal is very important because it helps dentists clean, shape, and fill the canal properly, which improves the success of the treatment and reduces the risk of complications.

In this study, two different techniques will be evaluated. The first method uses small hand instruments (manual technique) to create a smooth pathway inside the root canal before measuring its length. The second method uses a machine-assisted system (mechanical technique) that creates this pathway automatically. Both methods use special electronic devices called apex locators, which help determine the exact length of the root canal more accurately than traditional X-rays alone.

Participants in this study will be patients who require root canal treatment on lower molar teeth. If you agree to take part, you will receive standard root canal treatment similar to routine dental care. The only difference is the method used to prepare the canal and measure its length, which will be randomly assigned. This means neither you nor the dentist will choose the method, ensuring fair comparison.

The procedure will include taking dental X-rays, administering local anesthesia, cleaning and shaping the root canal, and filling it after measurement. All steps follow standard dental practices and safety protocols. Your treatment will not be compromised in any way by participating in the study.

The purpose of this research is to determine which method is more accurate, efficient, and reliable. The results may help improve future dental treatments by guiding dentists toward better techniques, ultimately benefiting patients through safer and more effective care.

Participation in this study is completely voluntary. You have the right to refuse participation or withdraw at any time without affecting your dental treatment. All personal and medical information will be kept confidential and used only for research purposes.

There are minimal risks involved, as all procedures are part of routine root canal treatment. You may not receive direct personal benefit, but your participation will contribute to improving dental care for others in the future.

Inclusion Criteria:

1. Both sex.

2. Aged 18 to 60 years.

3. Lower first permanent molars seeking root canal treatment.

4. Teeth exhibiting symptomatic irreversible pulpitis with normal periapical tissues.

5. Teeth with mature apex.

6. 3 visible canals from orifice to apex.

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Exclusion Criteria:

1. Teeth with metallic restorations or previous root treated teeth.
2. Fractured , teeth with immature apices, or developmental anomalies.
3. Systemic disease and immune deficiency.
4. Canals where the mechanical glide path could not be established.
5. Teeth with canal calcification or root resorption.

Individual participant data will not be shared due to participant privacy concerns, consent limitations, and regulatory requirements. Protecting confidentiality and adhering to ethical and legal standards takes priority.