Shaping effectiveness and surface topography of reciprocating files after multiple simulated uses

Area of Science:

• Endodontics
• Dental Materials Science
• Biomaterials

Background:

• Reciprocating instruments offer advantages in root canal preparation.
• Understanding the long-term wear and efficiency of these instruments is crucial for clinical practice.

Purpose of the Study:

• To evaluate the morphological changes and shaping efficiency of Reciproc R25 files after multiple uses in simulated root canals.

Main Methods:

• In vitro study using 10 Reciproc R25 files and 60 Endo Training Blocks.
• Scanning electron microscopy (SEM) assessed wear variables (fatigue cracks, metal strips, pitting, fretting, debris, cutting edge disruption, plastic deformation).
• AutoCAD software quantified prepared areas in resin blocks to assess shaping efficiency.

Main Results:

• Progressive wear was observed in Reciproc files with repeated use.
• Significant differences in fatigue cracks and metal strips/flash were noted between unused and heavily used (4-5 times) instruments.
• Shaping efficiency, measured by prepared area, significantly decreased with an increased number of instrument uses.

Conclusions:

• Repeated use of Reciproc files leads to progressive wear and degradation of their morphological integrity.
• The shaping efficiency of Reciproc files is negatively impacted by multiple uses, highlighting the need for careful instrument management.