Influence of different endodontic sealers on bond strength of fiber posts to weakened roots after resin restoration

Ultrasonic activation of the endodontic sealer enhances its intratubular penetration and bond strength to irradiated root dentin

To evaluate the effect of ultrasonic activation of the endodontic sealer on its intratubular penetration and bond strength to irradiated root dentin. Forty human teeth were distributed into 4 groups (n = 10), according to the radiation therapy (RT) exposure-70 Gy-and ultrasonic activation (UA) of the endodontic sealer: RT/UA-irradiated teeth and sealer UA; RT/no-UA-irradiated teeth and no sealer UA; no-RT/UA-non-irradiated teeth and sealer UA and no-RT/no-UA-non-irradiated teeth and no sealer UA. Push-out bond strength test was performed in a Universal Testing Machine. Failure modes and adhesive interface were analyzed under Scanning Electron Microscopy. The data were statistically compared (two-way-ANOVA and posthoc Games-Howell test; Fisher's exact test - α = 5%). The different experimental conditions (radiation and UA) and the root third had a significant effect on push-out bond strength, and the interaction of these factors was significant (p < 0.05). UA of the sealer significantly increased its bond strength to both irradiated and non-irradiated dentin (p < 0.05). The irradiated groups mostly presented adhesive-type failure of the sealer (p < 0.01). Regardless of the irradiation, the ultrasonically activated groups showed a more homogeneous adhesive interface, with the presence of sealer tags in greater density and depth. Ultrasonic activation enhanced the intratubular penetration and the bond strength of the endodontic sealer to irradiated dentin. The impact of ultrasonic activation of the endodontic sealer on teeth undergoing radiotherapy is a gap in the scientific literature that needs to be bridged.

Physicochemical properties of AH plus bioceramic sealer, Bio-C Sealer, and ADseal root canal sealer

BACKGROUND

The aim of this study was to evaluate the physicochemical properties of two newly introduced premixed calcium silicate-based root canal sealers (AH Plus Bioceramic Sealer and Bio-C Sealer) compared to a resin-based root canal sealer (ADseal root canal sealer).

METHODS

Solubility, pH analysis, calcium ion release, and film thickness of each sealer were evaluated following ISO guidelines. The data were examined using the two-way ANOVA test. Furthermore, X-ray diffraction (XRD) examination was performed to investigate the crystalline phase of each type of sealer. X-ray fluorescence (XRF) analysis was done for the chemical elemental analysis of each sealer.

RESULTS

The least film thickness, highest alkalinity, and highest calcium ion release were all displayed by AH Plus Bioceramic Sealer. High solubility, high alkalinity, intermediate calcium ion release, and intermediate film thickness were all displayed by Bio-C Sealer. While ADseal root canal sealer displayed the greatest film thickness, least solubility, alkalinity, and calcium ion release.

CONCLUSIONS

Both AH Plus Bioceramic Sealer and Bio-C Sealer represented adequate properties to be considered a good sealer that could be used as a potential alternative to resin-based root canal sealers.

The Effect of Different Fiber Post-Application Techniques on Fracture Resistance of Structurally Compromised Premolars with Flared Root Canals: An In Vitro Study

Aim:

Intraradicular post systems have become an important treatment method for endodontically treated teeth as they provide retention for restoration to the remaining tooth structure. The objective of the present in vitro study was to evaluate the effect of different fiber post-application techniques on the fracture resistance of premolars with flared root canals and no ferrule.

Materials and Methods:

Sixty freshly extracted, single-rooted mandibular premolars with no ferrule were endodontically treated by an experienced endodontist, and their root canals were experimentally flared. The specimens with flared root canals were divided into five groups according to fiber post-application techniques ( n = 12): a prefabricated fiber post (G1), G1 + two auxiliary posts (G2), i-TFC post system (G3), G1 + quartz splint (G4), and Ribbond (G5). The data were analyzed with analysis of variance and Tukey tests.

Results:

The findings were revealed that no significant difference was found among four groups, except G5 ( P > .05), which demonstrated the lowest fracture resistance ( P < .05). G2, G3, G4, and G5 exhibited dominantly restorable fracture pattern, whereas G1 exhibited nonrestorable fracture pattern.

Conclusion:

Within the limitations of this study, the placement of auxiliary posts, i-TFC post system, quartz splint placement, and Ribbond increased the incidence of restorable fracture compared with the controls.