Minimal Dentinal Tubule Penetration of Endodontic Sealers in Warm Vertical Compaction by Direct Detection via SEM Analysis

Abstract

Sealer staining using rhodamine B dye to investigate the penetration depth of endodontic sealers was proven unsuitable for this purpose. This study aimed to investigate the sealer penetration depth into dentinal tubules by scanning electron microscopy (SEM). Root canals of 52 human upper central incisors were instrumented using the ProTaper Gold NiTi system (Dentsply Sirona, York, PA, USA) up to size F3. After irrigation with sodium hypochlorite and citric acid combined with ultrasonic activation, the root canals were either filled using the epoxy resin sealer AH Plus (Dentsply Sirona) or the calcium silicate-based sealer Total Fill BC Sealer HiFlow (TFHF, FKG Dentaire, La Chaux-de-Fonds, Switzerland) by warm vertical compaction. Root slices of 1 mm thickness were obtained at 2 to 3, 5 to 6 and 8 to 9 mm from the apex. The root slices were investigated for sealer penetration into the dentinal tubules using SEM according to four root quadrants (buccal, mesial, oral, distal). Statistical analysis was performed by the Kruskal-Wallis test (p = 0.05) as data were not normally distributed according to the Shapiro-Wilk test. AH Plus penetrated significantly deeper into the dentinal tubules compared to TFHF at each root level (p < 0.05). Dentinal sealer penetration was deeper in the bucco-oral direction compared to the mesio-distal direction. AH Plus penetrated deeper into dentinal tubules than TFHF. Warm vertical compaction exerting high pressure on the root canal filling material is not able to press sealers deep into dentinal tubules as penetration depth values did not exceed a mean of 110 µm in SEM.

Evaluation of Bond Strength of Four Different Root Canal Sealers

“…Tubule penetration enhances the contact area between dentin and root filling materials, improving the sealing of the root canal system. Nonetheless, our study revealed, consistent with previous research performed by Schmidt et al [ 50 ] (TotalFill BC sealer), Song et al [ 57 ] (EndoSeal MTA), and Atmeh et al [ 56 ] (BioRoot), that the depth of extension for bioceramic sealers is relatively modest, with no differences between tested materials. RSSE penetrated more deeply into the dentin tubules in comparison to the bioceramic sealers.…”

“…Scanning electron microscopy (SEM) has been deployed in previous studies to highlight the sealer characterization, to analyze the sealer–dentin interface and sealer’s penetration into dentinal tubules [ 50 , 51 , 52 , 53 , 54 , 55 ]. In similar studies, a comparable number of samples were selected for SEM investigation [ 35 ].…”

Gap volume and sealer penetration of C‐shaped root canals obturated with cold hydraulic technique and calcium silicate sealer

“…The small BCS particle size (~2 μm) may enhance penetration of the sealer into the groove site dentine, which is generally sclerotic, containing fewer and smaller dentinal tubules [18]. A particle size of up to 8 μm was reported for AH Plus [19], therefore, less penetration occurred compared with the BCS group. In the non‐groove site, AH Plus sealer penetration using WHC/ERS may be improved by vertical compaction force and heat from the tip of the plugger [19].…”

“…A particle size of up to 8 μm was reported for AH Plus [19], therefore, less penetration occurred compared with the BCS group. In the non‐groove site, AH Plus sealer penetration using WHC/ERS may be improved by vertical compaction force and heat from the tip of the plugger [19]. The viscosity of AH Plus after heat application is lower for deeper dentinal tubule penetration.…”

Effect of Endodontic Bioceramic Sealer versus Resin Based Sealer in The Bond Strength of Fiber Posts Luted with Resin Cement to Root Dentin (An In-Vitro Study)

“…No ultrasonic irrigation was undertaken to avoid artifacts caused by sealer removal from the tubules. 20 Finally, the prepared slices were dried.…”