Do separated instruments affect pH levels when using calcium hydroxide as intracanal dressing?

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Intracanal separated instruments are a complication in endodontic treatment.
• Calcium hydroxide (CH) is a common intracanal medicament used to manage periapical health.

Purpose of the Study:

• To investigate the influence of different lengths of intracanal separated instruments on periapical pH levels.
• To assess the efficacy of calcium hydroxide (CH) as an intracanal medicament in the presence of separated instruments.

Main Methods:

• Sixty teeth were prepared and divided into four groups.
• Separated instruments (2 mm and 4 mm) were introduced into the apical portion of root canals in Groups 1 and 2.
• Calcium hydroxide (CH) paste was applied to Groups 1, 2, and 3, while Group 4 served as a control without CH or separated instruments.
• Periapical pH was measured at various time points up to 30 days.

Main Results:

• Group 3 (no separation, with CH) exhibited significantly higher pH at 1 hour compared to Groups 1 and 2.
• Group 2 (4 mm separation, with CH) showed significantly lower pH than Groups 1 and 3 at all measured time points (1, 2, 7, 15, and 30 days).
• Group 1 (2 mm separation, with CH) demonstrated a lower pH than Group 3 but higher than Group 2.

Conclusions:

• The presence and length of intracanal separated instruments can modulate the periapical pH environment when using calcium hydroxide (CH).
• A 4 mm separation in the apical third significantly affects periapical pH, potentially influencing the healing process.