Root canal sealer and contaminated dentin can be cleaned using various methods to achieve proper coronal seal and adhesion to dentin. The presence of remnants of root canal sealers affects the coronal seal and adhesion to dentin. The following are some methods that can be used to clean root canal sealer and contaminated dentin:

1. Cleaning with gutta-percha solvents: A study by Topçuoğlu et al. (2015) investigated the effect of different cleaning procedures using gutta-percha solvents on bond strength of adhesive resins to AH Plus contaminated dentin (APCD). The study found that cleaning with gutta-percha solvents can improve bond strength of adhesive resins to contaminated dentin.

2. Removal of smear layer: [2] found that the presence of smear layer affects negatively the adhesion of root canal sealers because it forms an interface between the sealing material and dentin, hindering or impeding sealer penetration into the dentinal tubules.

3. Cleaning with irrigation solutions: Çakır (2023) cleaned the dentin of primary teeth contaminated with root canal sealers (AH Plus, MTA Fillapex) with different irrigation solutions (saline, NaOCI, ethanol). 4. Cleaning with ultrasound or combined with acetone: [4] found that cleaning epoxy resin-based sealer-contaminated dentin surfaces using ultrasound or combined with acetone could preserve the bond strength.

5. Laser-EDTA cleansing effect phenomenon: Miletić et al. (2016) validated the laser‐EDTA cleansing effect phenomenon as an optimal cleansing method, which could also enhance the bond strength of sealers to root canal dentin.

6. Cleaning with sodium chlorite or ethanol: [6] divided specimens into four groups according to the cleaning method of dentin used: G1, no root canal sealer (control); G2, 0.9% sodium chlorite (NaCl); G3, ethanol; and G4, followed by diamond drill.

7. Sealer removal protocols: [7] compared the efficacy of different sealer removal protocols on the microtensile bond strengths (MTBS) of single step adhesives to a calcium silicate-based bioceramic root canal sealer contaminated dentin.

8. Adhesive properties of root canal sealers: [8]investigated the adhesive properties of eight root canal sealers, applied as a thin layer between a dentine and a gutta-percha surface.

9. Rubber dam isolation: [10] suggest performing rubber dam isolation to avoid contamination of the enamel bonding surface, allowing a clean restorative environment, with a correct visualization of the gingival margin during the adjustment of the veneer restorations, and finally to facilitate the removal of excess cement.

REFERENCES

[1] (2015). The bond strength of adhesive resins to AH plus contaminated dentin cleaned by various gutta-percha solvents. Scanning, 2(37), 138-144. https://doi.org/10.1002/sca.21190

[2] (2008). Adhesion of Epiphany and AH Plus sealers to human root dentin treated with different solutions. Braz. Dent. J., 1(19), 46-50. https://doi.org/10.1590/s0103-64402008000100008

[3] (2023). The Effect of Different Cleaning Materials on the Bond Strength of Resin Composite to Primary Teeth Dentin Contaminated with Root Canal Sealer.. https://doi.org/10.21203/rs.3.rs-2591855/v1

[4] (2022). Microtensile bond strength to sealer-contaminated dentin after using different cleaning protocols. Journal of Dental Sciences, 1(17), 122-127. https://doi.org/10.1016/j.jds.2021.05.016

[5] (2016). Effect of photon induced photoacoustic streaming (PIPS) on bond strength to dentine of two root canal filling materials. Lasers Surg. Med., 10(48), 951-954. https://doi.org/10.1002/lsm.22536

[6] (2016). Effect of cleaning methods on bond strength of self-etching adhesive to dentin. J Conserv Dent, 1(19), 26. https://doi.org/10.4103/0972-0707.173189

[7] (2021). The Efficacy of Different Sealer Removal Protocols on the Microtensile Bond Strength of Adhesives to a Bioceramic Sealer-Contaminated Dentin.. https://doi.org/10.21203/rs.3.rs-448214/v1

[8] (1990). Adhesion of root canal sealers to bovine dentine and gutta-percha. Int Endod J, 1(23), 13-19. https://doi.org/10.1111/j.1365-2591.1990.tb00797.x

[9] (2022). The efficacy of different sealer removal protocols on the microtensile bond strength of adhesives to a bioceramic sealer-contaminated dentin. Niger J Clin Pract, 3(25), 336. https://doi.org/10.4103/njcp.njcp_1575_21

[10] (2017). A Step-by-Step Conservative Approach for CAD-CAM Laminate Veneers. Case Reports in Dentistry, (2017), 1-6. https://doi.org/10.1155/2017/3801419

The question of whether it is better to treat maxillary incisors with or without dowel or ferrule is a complex one that depends on various factors. Several studies have investigated the effects of ferrule and dowel on the fracture resistance of endodontically treated maxillary incisors.

One study found that endodontically treated maxillary incisors with a uniform 2 mm ferrule were more fracture-resistant than those with a uniform 1 mm ferrule [3].

Another study investigated the effects of using different diameters of parallel cast posts with or without ferrule on the overall fracture resistance of Cast Post and Core (CPC) and found that the use of a ferrule increased the fracture resistance of the CPC [1].

However, other studies have found that the presence of a ferrule did not significantly affect the fracture resistance of endodontically treated maxillary incisors [2][5].

The use of dowels and cores can also affect the fracture resistance of endodontically treated maxillary incisors. One study compared the fracture resistance of endodontically treated central maxillary incisors prepared with different types of dowel and core materials and found that the use of glass fiber dowels resulted in the highest fracture resistance [6].

Another study investigated the effect of a cervical cavity extending 1 mm apical to the cemento-enamel junction (CEJ) on fracture resistance and failure mode of maxillary central incisors that have been treated endodontically, present with complete and incomplete ferrules, and are restored with and without a fiber post [4].

In conclusion, the decision to treat maxillary incisors with or without dowel or ferrule depends on various factors, including the extent of tooth structure loss, the presence of a cervical cavity, and the type of dowel and core material used. It is important to consider each case individually and to use evidence-based techniques to ensure the best possible outcome.

REFERENCES

[1] (2019). Effects of Ferrule and Diameter of Parallel Cast Post and Core on Fracture Resistance. BDS, 4(22), 538-545. https://doi.org/10.14295/bds.2019.v22i4.1720 [2] (2017).

The influence of crown ferrule on fracture resistance of endodontically treated maxillary central incisors. Balkan J Dent Med, 3(21), 44-49. https://doi.org/10.1515/bjdm-2017-0006 [3] (2014).

Fracture resistance of endodontically treated maxillary central incisors with varying ferrule heights and configurations: In vitro study. J Conserv Dent, 2(17), 115. https://doi.org/10.4103/0972-0707.128038 [4] (2021).

Effect of Cervical Lesions on Fracture Resistance and Failure Mode of Maxillary Central Incisors Restored with Fiber Posts and Complete Crowns. Operative Dentistry, 6(46), 669-679. https://doi.org/10.2341/20-164-l [5] (2008).

The finite element analysis of the effect of ferrule height on stress distribution at post-and-core-restored all-ceramic anterior crowns. Clin Oral Invest, 2(13), 223-227. https://doi.org/10.1007/s00784-008-0217-5 [6] (2019).

Evaluation of Fracture Resistance and Sites of Failure of Different Dowel Core Restorations: An In-Vitro Study. TODENTJ, 1(13), 454-461. https://doi.org/10.2174/1874210601913010454

The C-factor, which is the ratio between bonded and non-bonded surfaces, has been found to have an effect on the bonding of fiber posts to root canal dentin. Studies have shown that a high C-factor, such as in the post hole, can lead to lower bond strength of the adhesive system to root canal dentin [3].

However, the use of intracanal medicaments such as CH, CH+CHX, and TAP have been found to enhance the pull-out bond strength of fiber posts to root canal wall as compared to the control group [1].

Other factors that have been found to influence the interfacial bond between fiber posts and root canal dentin include resin volume, adhesive system, root canal region, and the use of Er,Cr:YSGG laser irradiation [2][4][5].

Additionally, treatments such as Er:YAG laser irradiation with/without EDTA and the use of MTA have been found to enhance the bond strength of fiber posts to root canal dentin walls [7][6].

The effect of root canal irrigants such as CH and SH on the push-out bond strength of fiber posts cemented with an etch-and-rinse resin cement has also been studied, with CH showing a higher bond strength compared to SH [8].

Here are the references

[1] (2019). Effect of Intracanal Medicaments on Pull-Out Bond Strength of Fiber Post Cemented with a Self-Adhesive System. Eur J Dent, 03(13), 420-425. https://doi.org/10.1055/s-0039-1694313 [2] (2011).

Effects of C-factor and resin volume on the bonding to root canal with and without fibre post insertion. Journal of Dentistry, 6(39), 422-429. https://doi.org/10.1016/j.jdent.2011.03.007 [3] (2009).

Effect of relining on fiber post retention to root canal. J. Appl. Oral Sci., 6(17), 600-604. https://doi.org/10.1590/s1678-77572009000600012 [4] (2015).

Effect of Resin Cement Pre-heating on the Push-out Bond Strength of Fiber Post to Root Canal Dentin. J Dent Res Dent Clin Dent Prospects, 4(9), 233-238. https://doi.org/10.15171/joddd.2015.042 [5] (2012).

Effect of Er,Cr:YSGG pretreatment on bond strength of fiber posts to root canal dentin using a self-adhesive resin cement. Lasers Med Sci, 1(28), 65-69. https://doi.org/10.1007/s10103-012-1063-x [6] (2016).

Does MTA affect fiber post retention in repaired cervical root canal perforations?. Braz. oral res., 1(30). https://doi.org/10.1590/1807-3107bor-2016.vol30.0083 [7] (2013).

Efficacy of different treatments of root canal walls on the pull-out bond strength of the fiber posts. Lasers Med Sci, 2(30), 863-868. https://doi.org/10.1007/s10103-013-1457-4 [8] (2021).

Effect of Calcium Hypochlorite and Sodium Hypochlorite as Root Canal Irrigants on Push-Out Bond Strength of Fiber Post Cemented with Etch-and-Rinse Resin Cement: An In Vitro Study. fid. https://doi.org/10.18502/fid.v18i18.6325

Additive effects of touch activated polymerization have been studied in the context of bonding to root canal dentin. Studies have shown that stresses from polymerization shrinkage and problems with adequate access to the root canal complicate the formation of high-strength bonds when cementing endodontic posts with resin cements [1].

The effects of different bonding systems with various polymerization modes and root canal regions on the bond strength of core build-up resin composite to dentin have also been investigated [2][4].

The interaction of geometrically related factors predicts that bonding of adhesive root-filling materials to root canals is highly unfavorable when compared with indirect intracoronal restorations with a similar resin film thickness [3].

Resin cement polymerization results in shrinkage, creating micro gaps between the fiber-reinforced composite (FRC) posts and the root canal wall [7].

The BS of fiber posts to root canals can be improved by soft-started polymerization [6].

The effect of composite post placement and/or light-irradiation of dual-cure resin composite on adhesion to root canal dentin using the chemical activation mode of a 1-step self-etch dual-cure adhesive has also been evaluated [8].

The activity of matrix metalloproteinases (MMPs) following endodontic irrigation protocols and correlation to the push-out bond strength (PBS) and nanoleakage expression (NL) in the root dentin have been studied [9].

Finally, the mechanical properties of the bonding agent, which could be enhanced by adequate polymerization, have been shown to affect the bond strength to root canal dentin [10].

[1] (2003). Microtensile bond strength between adhesive cements and root canal dentin. Dental Materials, 3(19), 199-205. https://doi.org/10.1016/s0109-5641(02)00030-1

[2] (2021). Effects of different bonding systems with various polymerization modes and root canal region on the bond strength of core build-up resin composite. J Prosthodont Res, 4(65), 521-527. https://doi.org/10.2186/jpr.jpr_d_20_00251

[3] (2005). Geometric Factors Affecting Dentin Bonding in Root Canals: A Theoretical Modeling Approach. Journal of Endodontics, 8(31), 584-589. https://doi.org/10.1097/01.don.0000168891.23486.de

[4] (2021). Effects of different bonding systems with various polymerization modes and root canal region on the bond strength of core build-up resin composite. J Prosthodont Res, 4(65), 521-527. https://doi.org/10.2186/jpr.jpr-d-20-00251

[5] (2020). Novel Bioactive and Therapeutic Root Canal Sealers with Antibacterial and Remineralization Properties. Materials, 5(13), 1096. https://doi.org/10.3390/ma13051096

[6] (2017). Is the bonding of self-adhesive cement sensitive to root region and curing mode?. J. Appl. Oral Sci., 1(25), 2-9. https://doi.org/10.1590/1678-77572015-0430

[7] (2020). The Effects of Differences in Post Canal Widths on Microleakage in Prefabricated Fiber Reinforced Composites. sod, 2(5), 1-8. https://doi.org/10.28932/sod.v5i2.2432

[8] (2010). Effect of composite post placement on bonding to root canal dentin using 1-step self-etch dual-cure adhesive with chemical activation mode. Dent. Mater. J., 6(29), 642-648. https://doi.org/10.4012/dmj.2010-006

[9] (2022). In Situ Zymography Analysis of Matrix Metalloproteinases Activity Following Endodontic Irrigation Protocols and Correlation to Root Dentine Bond Strength. Polymers, 17(14), 3567. https://doi.org/10.3390/polym14173567

[10] (2005). Regional Bond Strength of Four Self-etching Primer/Adhesive Systems to Root Canal Dentin. Dental Materials Journal, 2(24), 261-267. https://doi.org/10.4012/dmj.24.261