Lateral perforation in parallel post space preparations.

Area of Science:

• Endodontics
• Restorative Dentistry
• Dental Materials

Background:

• Post-endodontic restorations require post space preparation.
• The use of parallel-sided drills for post space preparation can risk root perforation.
• Mandibular molar distal canals present varying degrees of curvature.

Purpose of the Study:

• To evaluate remaining tooth structure after using different Parapost drill diameters.
• To assess the risk of lateral root perforation in mandibular molars with varying canal curvatures.
• To determine the influence of drill size and canal curvature on perforation risk.

Main Methods:

• Digital radiographs were used to measure remaining tooth structure.
• Three sizes of parallel-sided Parapost drills (#1, #2, #3) were used.
• Distal canals of mandibular molars were categorized into three curvature groups (0-15°, 16-25°, >26°).

Main Results:

• No significant difference in remaining tooth structure was found across curvature groups or drill sizes.
• Statistically significant differences in root perforation risk were observed at deeper levels (c and d) with the #3 drill.
• No strip perforations were detected in any group.

Conclusions:

• The #3 Parapost drill poses a higher risk of lateral root perforation in mandibular molars, particularly in apical regions.
• Drill diameter, not canal curvature, was the significant factor for perforation risk at deeper levels.
• Careful consideration of drill size is crucial to minimize perforation during post space preparation.