Efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - An in-vitro study

Background

A successful root canal treatment involves the elimination of microorganisms, and prevents them from reinfecting the root and/or peri-radicular tissues. This can be mainly achieved by efficient cleaning and shaping of the root canal system. Due to the complexity of the root canal morphology, hand and rotary files cannot clean areas such as the isthmuses and lateral canals. In such cases, effective irrigation and the use of intracanal medicaments are essential. Medicaments that are applied should be removed before obturation.

Aim

To evaluate the efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - Triple antibiotic paste (TAP), Odontopaste, and Metapex using a stereomicroscope.

Methodology

A total of 45 single-rooted human teeth were selected and decoronated. The root canals were shaped with ProTaper rotary files. The specimens were fixed in modified Eppendorf vials with silicone material. The roots were split longitudinally, and a standardized groove was prepared in the apical part. The teeth were randomly divided into three groups each containing 15 samples based on the intracanal medicament used: TAP, Odontopaste, and Metapex.

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The root halves were reassembled with sticky wax and remounted in the Eppendorf vial. Each specimen was irrigated with 3% NaOCl and agitated using a passive ultrasonic device. The root segments were disassembled. Digital images were obtained using a stereomicroscope.

Results

The data were evaluated statistically using Kruskal-Wallis and Mann-Whitney U tests. There was a statistically significant difference in the remaining intracanal medicament score (P < 0.05).

Conclusion

Odontopaste showed the least remaining amount score, whereas TAP and Metapex showed greater retention within the dentin.

Spectrophotometric insights: calcium hydroxide influences tooth discolorations induced by short-term application of antibiotic/corticosteroid pastes

OBJECTIVES

This in vitro study aimed to assess the influence of a calcium hydroxide dressing regarding the relative color change (ΔE) of enamel-dentin specimens previously exposed to antibiotic/corticosteroid pastes.

MATERIALS AND METHODS

Eighty bovine enamel-dentin specimens with a cylindrical central cavity were randomly allocated to four groups: NEG (empty), POS (blood), LED (Ledermix), and ODO (Odontopaste) (n = 20 each). The materials were applied and sealed with self-adhesive resin luting material. After 3 weeks, the materials were removed and a calcium hydroxide (Ca(OH)₂) dressing was placed in all cavities. After a further 3-week storage period, the cavities were restored with resin-based composite. Spectrophotometric color measurements were taken over 6 months, and ΔE values were calculated. A Tukey's multiple comparison test was performed to assess significant differences within the treatment groups (p < 0.05).

RESULTS

Tooth discolorations were present after 3 weeks in LED (ΔE 29.14 ± 6.55) and POS (ΔE 18.05 ± 7.03); NEG and ODO remained color stable (ΔE 3.2 ± 1.36 and ΔE 2.3 ± 1.16). The 3-week Ca(OH)₂ dressing decreased discolorations of POS (ΔE 15.93 ± 6.63; p = 0.37), whereas LED showed a further significant increase (ΔE 39.55; p < 0.0001). Between the end of the Ca(OH)₂ dressing and the final restoration no significant color changes were observed in any group (p > 0.9).

CONCLUSIONS

Discolorations induced by LED progressed during the Ca(OH)₂ dressing despite careful removal of all residues.

CLINICAL RELEVANCE

Calcium hydroxide might negatively affect the discoloring potential of Ledermix. This highlights the need for direct intracanal application methods of Ledermix ensuring a material-free access cavity or alternative antibiotic/corticosteroid pastes such as Odontopaste should be used.