Comparative Evaluation of Obturation Techniques on the Retrievability of NeoSealer Flo Bioceramic Sealer: An Ex Vivo Study

Summary

This ex vivo study investigates the impact of single cone and cold lateral compaction obturation techniques on the retrievability of NeoSealer Flo bioceramic sealer during endodontic retreatment. Results demonstrate that the single cone technique allows for more effective retrieval than cold lateral compaction.

Abstract

The successful retreatment of root canal-treated teeth depends largely on the effective removal of existing filling materials. This study aimed to evaluate the influence of two obturation techniques, single cone (SC) and cold lateral compaction (CLC), on the retrievability of NeoSealer Flo bioceramic sealer during endodontic retreatment. Twenty-four extracted single-rooted mandibular premolars with standardized root canal morphology were mechanically prepared and randomly allocated into two equal groups according to the obturation technique employed (n = 12). Following obturation with NeoSealer Flo, specimens were stored for 14 days under controlled conditions to allow complete setting of the sealer. Retreatment procedures were then performed using rotary retreatment files according to manufacturers’ recommendations. The amount of residual filling material remaining after retreatment was assessed in the coronal, middle, and apical thirds of each root using stereomicroscopic examination and quantified through ImageJ software analysis. Additionally, the total time required to complete retreatment procedures was recorded. Statistical analysis was performed with a significance level set at p < 0.05. The results demonstrated that canals obturated using the CLC technique had significantly greater residual filling material in the middle and apical thirds compared to the SC technique. No statistically significant difference was observed between groups regarding retreatment time. Within the limitations of this in vitro study, the findings suggest that NeoSealer Flo is more readily removed when used with the single cone obturation technique, highlighting the importance of obturation method selection when bioceramic sealers are employed in clinical practice.

Introduction

A successful endodontic outcome depends on achieving and maintaining an effective three-dimensional seal of the root canal system, thereby preventing bacterial recontamination and supporting long-term periapical health¹. In recent years, the advent of bioceramic sealers has shifted the obturation paradigm from one focused primarily on mechanical filling to an approach that emphasizes bioactivity and chemical interaction with dentin². Resin-free bioceramic materials such as NeoSealer Flo are formulated to release calcium hydroxide during their setting reaction, promoting an alkaline environment with antimicrobial properti....

Protocol

This study was conducted and reported in accordance with the PRILE guidelines (Supplementary File 1), and the overall experimental workflow is summarized in the PRILE flowchart (Supplementary File 2).

Sample selection

CAUTION: Extracted human teeth represent a potential biohazard. Handle all samples using appropriate personal protective equipment (PPE), including gloves, masks, and protective eyewear. Dispose of all biological waste in designated biohazard containers according to institutional and local regulations.

The ....

Results

Following the rotary retreatment protocol using ProTaper Universal and Next files, full working length and apical patency were successfully regained in 100% of the samples across both the SC and CLC groups. No procedural complications, such as file separation, canal transportations, or perforations, were observed during the retreatment process.

Percentage of Residual Filling Material (Derived from ImageJ Area Measurements):
Based on the quantitative area measurements performed using ImageJ.......

Discussion

Bioceramic sealers are favored for their ability to penetrate complex canal anatomy, yet this study demonstrates that no technique ensures their total removal^10,3.

Complete removal of filling materials from the root canal system is essential to expose microbial biofilms sequestered within the dentinal tubules. This debridement allows for direct contact with irrigants and intracanal medicaments, which is critical for the eradication of .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bioceramic Sealer	Avalon Biomed, Houston, TX, USA	NeoSealer Flo
Glide Path File	Coltene/Whaledent AG, Altstätten, Switzerland	HyFlex EDM Glide Path (10/.05)
Shaping File	Coltene/Whaledent AG, Altstätten, Switzerland	HyFlex EDM OneFile (25/0.08)
Master Cone	Coltene/Whaledent AG, Altstätten, Switzerland	HyFlex EDM Gutta-Percha Cone
Ultrasonic Unit	Guilin Woodpecker Medical Instrument Co., China	Woodpecker Ultra X
Temporary Restorative Material	3M ESPE, Seefeld, Germany	Cavit
Digital Intraoral Sensor	DEXIS, Hatfield, PA, USA	Dexis Platinum
X-ray Unit	Planmeca, Helsinki, Finland	Planmeca ProX
Retreatment Files	Dentsply Sirona, Ballaigues, Switzerland	ProTaper Universal Retreatment (D1-D3)
Retreatment Finishing Files	Dentsply Sirona, Ballaigues, Switzerland	ProTaper Next (X2, X3)
Randomization Software	Microsoft Corp., Redmond, WA, USA	Microsoft Excel
Imaging Software	DEXIS, Hatfield, PA, USA	DEXIS Software
Image Analysis Software	National Institutes of Health, Bethesda, MD, USA	ImageJ
Statistical Analysis Software	R Foundation for Statistical Computing, Vienna, Austria	R version 4.3.1
Power Analysis Software	Heinrich-Heine-Universität, Düsseldorf, Germany	G*Power (v3.1.9.7)