Restor Dent Endod.  2024 May;49(2):e12. 10.5395/rde.2024.49.e12.

Impact of different agitation methods on smear layer cleaning of mesial canals with accentuated curvature

• Cordova AT
• Alcalde MP
• Klymus ME
• Bonjardim LR
• Vivan RR
• Duarte MAH

• KMID: 2556541
• DOI: http://doi.org/10.5395/rde.2024.49.e12

Abstract

Objectives
This study evaluated the impact of different methods of irrigant agitation on smear layer removal in the apical third of curved mesial canals of 3 dimensionally (D) printed mandibular molars.
Materials and Methods
Sixty 3D-printed mandibular second molars were used, presenting a 70° curvature and a Vertucci type II configuration in the mesial root. A round cavity was cut 2 mm from the apex using a trephine of 2 mm in diameter, 60 bovine dentin disks were made, and a smear layer was formed. The dentin disks had the adaptation checked in the apical third of the teeth with wax. The dentin disks were evaluated in environmental scanning electron microscope before and after the following irrigant agitation methods: G1(PIK Ultrasonic Tip), G2 (Passive Ultrasonic Irrigation with Irrisonic– PUI), G3 (Easy Clean), G4 (HBW Ultrasonic Tip), G5 (Ultramint X Ultrasonic tip), and G6 (conventional irrigation-CI) (n = 10). All groups were irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid.
Results
All dentin disks were 100% covered by the smear layer before treatment, and all groups significantly reduced the percentage of the smear layer after treatment. After the irrigation protocols, the Ultra-X group showed the lowest coverage percentage, statistically differing from the conventional, PIK, and HBW groups (p < 0.05). There was no significant difference among Ultramint X, PUI-Irrisonic, and Easy Clean (p > 0.05). None of the agitation methods could remove the smear layer altogether.
Conclusions
Ultramint X resulted in the most significant number of completely clean specimens.

Keyword

Irrigation methods; Scanning electron microscopy; Smear layer; 3D-printed

Figure

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  Figure 1 The sequence of placement of the dentin disk into the mesial root of a 3D-printed molar. (A) 3D tooth with 70° curvature. (B) Medial root showing the hole on the distal side, 2 mm from the apical foramen. (C) Dentin discs with a diameter of 2 mm. (D) Dentin disc adaptation at the apical third level. (E) Sealed with wax at the apical third level.3D, 3-dimensionally.

• 

  Figure 2 The image shows the different experimental groups.1: PIK adapted to an ultrasonic insert plus NSK ultrasonic. 2: Irrisonic E1 insert plus NSK ultrasonic. 3: Easyclean 25.04 with a pneumatic contra-angle. 4: HBW insert and digital spacing A plus NSK ultrasonic. 5: X Blue insert plus Ultra X ultrasonic.PUI, passive ultrasonic irrigation.

• 

  Figure 3 Representative scanning electron microscopy images before and after treatment in studied groups. (A and B) PIK pre and post; (C and D) PUI pre and post; (E and F) HBW pre and post; (G and H) Easyclean pre and post, (I and J) Ultramint X pre and post; (K and L); conventional pre and post (magnification 500× and 20 kV current).

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