UNIVERSIDADE ESTADUAL PAULISTA

“JÚLIO DE MESQUITA FILHO”

Instituto de Ciência e Tecnologia

Campus de São José dos Campos

SYSTEMATIC REVIEW DOI: https://doi.org/10.4322/bds.2023.e3856

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic review

As soluções de irrigação usadas durante a instrumentação do canal radicular inﬂuenciam a adesão de pinos de

ﬁbra de vidro? Uma revisão sistemática

Irma Gonçalves REYS1 , Ludmila Silva GUIMARÃES2 , Lorran Soares Duarte TERRA3 ,

Marlus Roberto Rodrigues CAJAZEIRA4 , Lívia Azeredo Alves ANTUNES1,2,4 , Leonardo Santos ANTUNES1,2,4 

1 - Universidade Federal Fluminense, Curso de Odontologia, Programa de Pós-Graduação. Nova Friburgo, RJ, Brazil.

2 - Universidade Federal Fluminense, Faculdade de Odontologia, Programa de Pós-Graduação. Niterói, RJ, Brazil.

3 - Universidade Federal Fluminense, Curso de Odontologia. Nova Friburgo, RJ, Brazil.

4 - Universidade Federal Fluminense, Curso de Odontologia, Departamento de Formação Especíca. Nova Friburgo, RJ, Brazil.

How to cite: Reys IG, Guimarães LS, Terra LSD, Cajazeira MRR, Antunes LAA, Antunes LS. Do irrigation solutions used during

root canal instrumentation inuence the adhesion of glass ber posts? A systematic review. Braz Dent Sci. 2023;26(3):e3856.

https://doi.org/10.4322/bds.2023.e3856

ABSTRACT

Statement of problem: the bond strength between adhesive cement and root dentin can be affected by irrigation

protocols. Purpose: therefore, the objective of this systematic review was to answer the following question:

Do irrigation solutions used during root canal instrumentation inuence the adhesion of glass ber posts to

root dentin? Material and Methods: this study followed the recommendations of PRISMA 2020 for writing.

PubMed, Scopus, Web of Science, and LILACS databases were searched for articles published until 26 January,

2022. Grey literature and a manual search were also performed. The inclusion criteria were based on the PICO

strategy: permanent human or animal teeth (P), which were irrigated during root canal instrumentation with

endodontic substances (I) and compared to irrigation with sodium hypochlorite at various concentrations (C)

to analyze the bond strength of glass ber posts (O). Two authors independently performed data extraction and

the risk of bias. Results: eight articles were included. Four articles were classied as having a high risk of bias,

where the others as medium risk. Studies have reported conicting results regarding the inuence of irrigating

solutions and the different concentrations of sodium hypochlorite on the adhesion of glass ber posts to root

dentin. Conclusion: the heterogeneity between studies did not allow the conclusion of a true estimate regarding

this topic, and further well-designed studies are needed to clarify this issue. Register: CRD42020221835.

KEYWORDS

Bond strength; Dentin; Glass ber post; Root canal irrigants; Shear strength.

RESUMO

Denição do problema: a resistência de união entre o cimento adesivo e a dentina radicular pode ser afetada

pelos protocolos de irrigação. Objetivo: portanto, o objetivo desta revisão sistemática foi responder à seguinte

questão: As soluções de irrigação usadas durante a instrumentação do canal radicular inuenciam a adesão de

pinos de bra de vidro à dentina radicular? Material e Métodos: este estudo seguiu as recomendações do PRISMA

2020 para sua redação. As bases de dados PubMed, Scopus, Web of Science e LILACS foram pesquisadas para

artigos publicados até 26 de janeiro de 2022. A literatura cinza e uma pesquisa manual também foram realizadas.

Os critérios de inclusão foram baseados na estratégia PICO: dentes humanos ou animais permanentes (P), que

foram irrigados durante a instrumentação do canal radicular com substâncias endodônticas (I) e comparados à

irrigação com hipoclorito de sódio em várias concentrações (C) para analisar a resistência de união de pinos de

bra de vidro (O). Dois autores realizaram independentemente a extração de dados e o risco de viés. Resultados:

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

INTRODUCTION

The aim of root canal treatment is to

prevent or eliminate infection of the root canal

system, mainly by shaping and cleaning the

canal using les, reamers, irrigation solutions

and antibacterial dressings [1]. The most

commonly used endodontic irrigation solution

is sodium hypochlorite, due to its ability to

dissolve organic tissues and high effectiveness in

reducing microorganisms in the root canal [2].

Chlorhexidine is a broad-spectrum antiseptic

solution that has also been used in endodontic

therapy to disinfect root canals or as an intracanal

medicament, or even as a final irrigant [3].

Chlorhexidine is less cytotoxic to periapical

tissues [3] and is also effective against a variety of

Gram-positive and Gram-negative oral bacterial

species [4], but its main limitation is the inability to

dissolve pulp tissue [5]. However, new substances

are being introduced into the root canal to

complement conventional chemomechanical

procedures [6], such as irrigants associated

with surfactants, chelators, tetracyclines [7,8],

ozonized water [9], photosensitizers with

photodynamic therapy [10], among others.

Teeth with signicant coronal destruction

and endodontically treated teeth usually require

glass ber posts to improve crown retention or

composite resin restorations [11]. Glass fiber

posts have several advantages, such as high

flexural strength, better distribution of the

stress generated, biocompatibility, and corrosion

resistance, in addition to an elasticity module

close to dentin [12,13]. However, failures can

occur, mainly due to failure in adhesion between

the adhesive cement and the inner walls of root

canals [14].

The bond strength of adhesive cement

and dentin can be affected by many factors,

such as the presence of root canal treatment,

pretreatment of the post, cementation method,

and use of irrigation protocols [15,16]. Some

studies have reported that the irrigation solutions

used during root canal treatment have signicant

statistical inuence on the adhesion of the glass

ber posts to dentin [15,17-20]; however, others

do not demonstrate this inuence [21-24].

Therefore, some concerns about the inuence

of endodontic irrigation solutions on the adhesion

of glass fiber posts are still significant [25],

mainly due to the few existing studies in the

literature on the subject and their heterogeneous

conclusions. To date, no systematic review has

evaluated this relationship. Although a systematic

review published in 2015 [16] addressed the

factors associated with the adhesion of glass

ber posts, the main objective was to assess the

inuence of variables related to post-cementation,

disregarding the substances used in endodontic

irrigation, reaffirming the importance of this

study for daily clinical management.

Therefore, the objective of this systematic

review was to answer the following question

structured according to PICO: Do irrigation

solutions used during root canal instrumentation

inuence the adhesion of glass ber posts to the

root dentin?

METHODS

This systematic review was registered in

PROSPERO (CRD42020221835) and followed

the recommendations of PRISMA (Preferred

Reporting Items for Systematic Review and Meta-

Analysis) guidelines for its writing [26].

Search strategy

The electronic databases PubMed, Scopus,

Web of Science, and Virtual Health Library

(LILACS) were searched for articles published

until 26 January 2022, without language, year

restrictions or limits. The selection process is

illustrated in Figure 1. The grey literature was

consulted through OpenGrey, and references

oito artigos foram incluídos. Quatro artigos foram classicados como de alto risco de viés, enquanto os demais

como de médio risco. Estudos relataram resultados conitantes sobre a inuência de soluções irrigadoras e

as diferentes concentrações de hipoclorito de sódio na adesão de pinos de bra de vidro à dentina radicular.

Conclusão: a heterogeneidade entre os estudos não permitiu a conclusão de uma estimativa verdadeira sobre este

tópico, sendo necessários mais estudos bem delineados para esclarecer esta questão. Registo: CRD42020221835.

PALAVRAS-CHAVE

Resistência de união; Dentina; Pino de bra de vidro; Irrigantes do canal radicular; Força de cisalhamento.

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

of the included studies were also searched to

identify other studies that might have been

missed in the initial electronic search. MeSH

terms “Sodium Hypochlorite”, “Chlorhexidine”,

“Root Canal Irrigants”, “Chelating Agents”,

“Edetic Acid”, “Photochemotherapy”, “Citric

Acid”, “Hydrogen Peroxide”, “Saline Solution”,

“Boric Acids”, “Post and Core Technique”,

“Adhesive”, “Shear Strength” and “Dentin”,

and DeCS terms “Sodium Hypochlorite”,

“Chlorhexidine”, “Root Canal Irrigants”, “Edetic

Acid”, “Photochemotherapy”, “Citric Acid”,

“Distilled Water”, “Hydrogen Peroxide”, “Saline

Solution”, “Post and Core Technique”, “Adhesive”,

“Shear Strength” and “Dentin” were used. MeSH

synonyms, related terms, and free terms were

also included. The Boolean operators “AND” and

“OR” were applied to combine these terms, and

the combination of these search descriptors is

shown in Table I.

Eligibility criteria

The eligibility criteria were based on the

PICO strategy, as follows:

Population (P): Permanent human teeth or

animal teeth

Intervention (I): Alternative irrigation solutions

used during root canal instrumentation

Comparison (C): Irrigation with sodium

hypochlorite in its various concentrations

Outcome (O): To analyze the bond strength of

glass ber posts.

Study design (S): Laboratory study.

Literature reviews, systematic reviews,

opinion articles, letters to the editor, guidelines,

case reports, studies that evaluated the

preparation of the root space for glass fiber

posts and intracanal medication in both human

and animal teeth, studies that did not compare

bond strength or endodontic irrigating solutions,

and articles outside the proposed theme were

excluded.

Selection of the studies

The results of the electronic search were

managed using Mendeley software. Two authors

(I.G.R. and L.S.G.) independently selected

the retrieved studies, examined the titles and

abstracts based on the eligibility criteria using

the PICO strategy. The selected articles were

read in full and only potential studies were

Figure 1 - Flowchart PRISMA 2020.

Records identified from:

Web of Science (n = 127)

Scopus (n = 158)

VHL (Lilacs) (n = 5)

Pubmed (n = 114)

Grey Literature (n = 0)

Registers (n = 0)

Records removed before

screening:

Duplicate records removed

(n = 176)

Records marked as ineligible

by automation tools (n = 0)

Records removed for other

reasons (n = 0)

Records screened

(n = 228)

Records excluded

(n = 190)

Reasons:

Post space preparation in

animal teeth (n = 19)

Records outside of the

proposed theme (n = 100)

Reviews or Systematic

Reviews (n = 7)

Post space preparation in

human teeth (n = 64)

Reports sought for retrieval

(n = 0)

Reports not retrieved

(n = 0)

Reports assessed for eligibility

(n = 38)

Reports excluded (n = 32)

Reasons:

Post space preparation in

animal teeth (n = 2)

Post space preparation in

human teeth (n = 23)

Assessment of intracanal

medication (n = 2)

Without evaluation of

endodontic irrigating solution

(n = 1)

Used saline solution or

distilled water for irrigation (n

= 4)

Records identified from:

Websites (n = 0)

Organizations (n = 0)

Citation searching (n = 3)

Reports assessed for eligibility

(n = 2)

Studies included in review

(n = 8)

Reports of included studies

(n = 0)

Identification of studies via databases and registers

Identification of studies via other methods

Identification

Screening

Included

Reports sought for retrieval

(n = 3)

Reports not retrieved

(n = 1)

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

included. A kappa match of 0.90 was calculated

to ensure reliability between the authors during

the selection. In case of disagreement regarding

the inclusion of the study, a third author (L.S.A.)

was contacted. Duplicate studies were removed

from the database and considered only once.

Table I - Electronic database used and search strategy

Database Search Strategy

PubMed

#1(Sodium Hypochlorite[MeSH Terms]) OR (Chlorhexidine[MeSH Terms])) OR (Root Canal Irrigants[MeSH Terms])) OR

(Chelating Agents[MeSH Terms])) OR (Edetic Acid[MeSH Terms])) OR (Photochemotherapy[MeSH Terms])) OR (Citric

Acid[MeSH Terms])) OR (Hydrogen Peroxide[MeSH Terms])) OR (Saline Solution[MeSH Terms])) OR (Boric Acids[MeSH

Terms])) OR (Sodium Hypochlorite[Title/Abstract])) OR (EDTA[Title/Abstract])) OR (Edetic Acid[Title/Abstract])) OR

(PDTa[Title/Abstract])) OR (Photodynamic Therapy[Title/Abstract])) OR (Photochemotherapy[Title/Abstract])) OR

(Antimicrobial Solutions[Title/Abstract])) OR (Chlorhexidine[Title/Abstract])) OR (Irrigation Solutions[Title/Abstract]))

OR (Root Canal Irrigants[Title/Abstract])) OR (Chelating Agents[Title/Abstract])) OR (Citric Acid[Title/Abstract])) OR

(Distilled Water[Title/Abstract])) OR (Hydrogen Peroxide[Title/Abstract])) OR (Urea Peroxide[Title/Abstract])) OR

(Saline Solution[Title/Abstract])) OR (Calcium Hydroxide Solution[Title/Abstract])) OR (Boric Acid[Title/Abstract])) OR

(Polyacrylic Acid[Title/Abstract])) OR (Silver Nanoparticle (Ag-NP) dispersion[Title/Abstract])

#2(Post and Core Technique[MeSH Terms]) OR (Glass Fiber Posts[Title/Abstract])) OR (Fiber Posts[Title/Abstract])) OR

(Dental Posts[Title/Abstract])) OR (Root Retainer[Title/Abstract])) OR (Post and Core Technique[Title/Abstract])

#3(Adhesive[MeSH Terms]) OR (Shear Strength[MeSH Terms])) OR (Adhesion[Title/Abstract])) OR (Shear Strength[Title/

Abstract])) OR (Push-out Strength[Title/Abstract])) OR (Adhesive[Title/Abstract])

#4(Dentin[MeSH Terms]) OR (Dentine[Title/Abstract])) OR (Root Dentin[Title/Abstract])) OR (Radicular Dentin[Title/

Abstract])) OR (Root Canal Dentin[Title/Abstract])) OR (Dentin[Title/Abstract])

#1 and #2 and #3 and #4

Scopus

#1(TITLE-ABS-KEY (“Sodium Hypochlorite”) OR TITLE-ABS-KEY (edta) OR TITLE-ABS-KEY (“Edetic Acid”) OR TITLE-ABS-

KEY (pdta) OR TITLE-ABS-KEY (“Photodynamic Therapy”) OR TITLE-ABS-KEY (photochemotherapy) OR TITLE-ABS-KEY

(“Antimicrobial Solutions”) OR TITLE-ABS-KEY (chlorhexidine) OR TITLE-ABS-KEY (“Irrigation Solutions”) OR TITLE-ABS-

KEY (“Root Canal Irrigants”) OR TITLE-ABS-KEY (“Chelating Agents”) OR TITLE-ABS-KEY (“Citric Acid”) OR TITLE-ABS-KEY

(“Distilled Water”) OR TITLE-ABS-KEY (“Hydrogen Peroxide”) OR TITLE-ABS-KEY (“Urea Peroxide”) OR TITLE-ABS-KEY

(“Saline Solution”) OR TITLE-ABS-KEY (“Calcium Hydroxide Solution”) OR TITLE-ABS-KEY (“Boric Acid”) OR TITLE-ABS-KEY

(“Polyacrylic Acid”) OR TITLE-ABS-KEY (“Silver Nanoparticle (Ag-NP) dispersion”))

#2(TITLE-ABS-KEY (“Glass Fiber Posts”) OR TITLE-ABS-KEY (“Fiber Posts”) OR TITLE-ABS-KEY (“Dental Posts”) OR TITLE-

ABS-KEY (“Root Retainer”) OR TITLE-ABS-KEY (“Post and Core Technique”))

#3(TITLE-ABS-KEY (adhesion) OR TITLE-ABS-KEY (“Shear Strength”) OR TITLE-ABS-KEY (“Push-out Strength”) OR TITLE-

ABS-KEY (adhesive))

#4(TITLE-ABS-KEY (dentine) OR TITLE-ABS-KEY (“Root Dentin”) OR TITLE-ABS-KEY (“Radicular Dentin”) OR TITLE-ABS-KEY

(“Root Canal Dentin”) OR TITLE-ABS-KEY (dentin))

#1 and #2 and #3 and #4

Web of

Science

#1TOPIC:(“Sodium Hypochlorite”)

TOPIC: (EDTA)

TOPIC: (“Edetic Acid”)

TOPIC: (PDTa)

TOPIC:

(“Photodynamic Therapy”)

TOPIC: (Photochemotherapy)

TOPIC: (“Antimicrobial Solutions”)

TOPIC:

(Chlorhexidine)

TOPIC: (“Irrigation Solutions”)

TOPIC: (“Root Canal Irrigants”)

TOPIC: (“Chelating Agents”)

TOPIC: (“Citric Acid”)

TOPIC: (“Distilled Water”)

TOPIC: (“Hydrogen Peroxide”)

TOPIC: (“Urea Peroxide”)

TOPIC: (“Saline Solution”)

TOPIC: (“Calcium Hydroxide Solution”)

TOPIC: (“Boric Acid”)

TOPIC: (“Polyacrylic

Acid”)

TOPIC: (“Silver Nanoparticle (Ag-NP) dispersion”)

Indexes=SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, ESCI Timespan= All years

#2TOPIC:(“Glass Fiber Posts”)

TOPIC: (“Fiber Posts”)

TOPIC: (“Dental Posts”)

TOPIC: (“Root Retainer”)

TOPIC: (“Post and Core Technique”)

Indexes=SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, ESCI Timespan= All years

#3TOPIC:(Adhesion)

TOPIC: (“Shear Strength”)

TOPIC: (“Push-out Strength”)

TOPIC: (Adhesive)

Indexes=SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, ESCI Timespan= All years

#4TOPIC:(Dentine)

TOPIC: (“Root Dentin”)

TOPIC: (“Radicular Dentin”)

TOPIC: (“Root Canal Dentin”)

TOPIC: (Dentin)

Indexes=SCI-EXPANDED, SSCI, A&HCI, CPCI-S, CPCI-SSH, ESCI Timespan= All years

#1 and #2 and #3 and #4

VHL

(LILACS)

(tw:(sodium hypochlorite OR chlorhexidine OR edetic acid OR photochemotherapy OR citric acid OR distilled water OR

hydrogen peroxide OR saline solution OR root canal irrigants)) AND (tw:(post and core technique)) AND (tw:(adhesive OR

shear strength)) AND (tw:(dentin))) AND (db:(“LILACS”))

Grey

Literature Root Canal Irrigants AND Glass Fiber Posts AND Adhesion AND Root Dentin

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Data extraction

Two independent authors (I.G.R. and L.S.G.)

collected the data from the included studies.

The authors of these primary studies were

contacted if data were absent. Data from the

included studies were compiled and organized

according to the following parameters: the rst

author of the article, year of publication, teeth

origin, n/group of teeth, root canal treatment

(irrigation solution groups during treatment (n),

nal irrigation solutions (n), instrumentation,

endodontic sealer), preparation of glass fiber

posts (drills used, glass fiber posts cleaning,

adhesive system/sealer), bond strength test, bond

strength values (mean/SD), and results (sodium

hypochlorite × other irrigation solutions and

different concentrations of sodium hypochlorite).

Quality assessment

The risk of bias was evaluated by two

independent reviewers (I.G.R. and L.S.G.)

using an instrument adapted for laboratory

studies [27-29], and assessed according to the

articles’ description of the following parameters:

randomization of teeth, use of materials according

to the manufacturer’s instructions, use of teeth

with similar dimensions, root canal treatment

performed by a single operator, standardization of

procedures, description of sample size calculation,

and blinding of the operator of the testing machine.

If the authors reported the parameter, the

article had “Yes” on that specic parameter; if

the information could not be found, the article

received “No”. Articles that reported one to three

“Yes” items were classied as high risk of bias,

four or ve “Yes” items as medium risk of bias,

and six or seven “Yes” items as low risk of bias.

Publication bias

Publication bias was verified in primary

studies when analyzing the greater probability

of these studies being published because of their

positive results, sample size and/or nanced by

companies.

RESULTS

Search strategy and selection of the studies

A total of 404 potentially relevant articles

were identied from PubMed (114), Scopus (158),

Web of Science (127), and LILACS (5) databases.

The grey literature was consulted through

OpenGrey, and no articles were found. After

removing duplicates, 228 articles were examined

for titles and abstracts. One hundred and ninety

studies were excluded because they did not

meet the eligibility criteria, and 38 articles

were approved for reading the entire text. After

applying the eligibility criteria after full reading,

32 studies were excluded and a total of 6 studies

were included in this review. Three additional

articles were identified by a manual search.

An article found in the manual search was not

found in the databases, and the authors and

co-authors were contacted to obtain the article,

but without success, making it impossible to select

this article for the study. Therefore, eight articles

were included in this study. Figure 1 summarizes

the selection process.

Parameters of the included studies

Four articles [17,18,21,30] used animal

teeth (bovine). Of these, two did not specify

which type of tooth they used [21,30] and two

used bovine incisors [17,18]. The remaining

four articles [20,22,24,31] used human

teeth. Two studies used single-rooted

human teeth [22,24], one study used human

premolars [20], and one study used human

c-shaped canal molars [31] (Table II).

Sodium hypochlorite was used as irrigation

solution during root canal treatment in all

studies [17,18,20-22,24,30,31], and this substance

is used in various concentrations, from 1%

to 5.25%. Another widely used substance is

chlorhexidine, at different concentrations of

0.2% [22] and 2% [17,18,21,24,30,31] (Table II).

Regarding the final irrigant used in root

canal treatment, most of the studies used

ethylenediaminetetraacetic acid (EDTA).

Two studies used EDTA with ultrasonic

vibration [18,21], and two articles used only

ETDA [17,24]. Two articles used distilled water

for nal irrigation [20,30] (Table II).

Most studies used manual instrumentation

[18,20,21,31]. Two studies performed rotary

instrumentation [22,24], and only one study

divided its sample and performed half manual

instrumentation and the other half rotary

instrumentation [17]. Finally, a study was

conducted on the instrumentation of the root

canal using a high-precision electric drill with

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Table II - Characteristics of included studies (n=8)

Author (Year) Teeth origin n/Group of

teeth

Root canal treatment Preparation of glass ﬁber posts Bond strenght

test

Irrigation solutions groups during treatment

(n)

Final irrigation

solutions (n) Instrumentation Endodontic

sealer Drills used Glass ﬁber

posts cleaning

Adhesive sys-

tem/Sealer

Pelegrineetal.,

2010 [21] Bovine 50/MD

G1: 0.9% NaCl (n=10)

EDTA with

ultrasonic

vibration +

Same irrigant

solutions

Modiﬁed step-

back technique

with manual

K-type ﬁles

and ﬂaring

was completed

using Gates-

Glidden #6 and

#5.

AH Plus #5 Largo

70% alcohol and

37% phosphoric

acid

Self-etch

2-step adhesive

system Clearﬁl

SE Bond +

RelyX ARC resin

cement

Tensile strength

test

G2: 1.0% NaOCl (n=10)

G3: 2.5% NaOCl (n=10)

G4: 5.25% NaOCl (n=10)

G5: 2% CHX-G + 0.9% NaCl (n=10)

Grassietal.,

2012 [22] Human 40/Single-

rooted

G1: 0.2% CHX + PCS (n=10)

Proﬁle

instrument to

master apical

rotary size

35–45.

G1: PCS

Gates-Glidden

According

to the

manufacturer

Dual adhesive

Surgi Primebond

Base + Surgi

Primebond

Activator/Surgi

Dual Flò Core

cement

Micro-push-out

test

G2: 5% NaOCl + PCS (n=10) G2: PCS

G3: 5% NaOCl + AX (n=10) G3: AX

G4: 0.2% CHX + AX (n=10) G4: AX

Santanaetal.,

2015 [17] Bovine 120/Incisors

G1: 1% NaOCl + SS + Immediate (n=10)

EDTA + Same

irrigant

solutions

SS: # 1,2

Gates-Glidden,

# 2 Largo and

stainless steel

instruments up

to #45 K-ﬁle.

Root canals

were not

ﬁlled to avoid

interference.

#3 to #5 Largo 70% alcohol

Self-adhesive

resin cement -

RelyX U100

Push-out test

with or without

artiﬁcial

accelerated

aging

G2: 2% CHX + SS + Immediate (n=10)

NiTi: # 1,2

Gates-Glidden

and K3 nickel-

titanium rotary

instruments.

G3: 1.2% O3 + SS + Immediate (n=10)

G4: 1% NaOCl + NiTi + Immediate (n=10)

G5: 2% CHX + NiTi + Immediate (n=10)

G6: 1.2% O3 + NiTi + Immediate (n=10)

G7: 1% NaOCl + SS + Aged (n=10)

G8: 2% CHX + SS + Aged (n=10)

G9: 1.2% O3 + SS + Aged (n=10)

G10: 1% NaOCl + NiTi + Aged (n=10)

G11: 2% CHX + NiTi + Aged (n=10)

G12: 1.2% O3 + NiTi + Aged (n=10)

MD: missing data; NaCl: sodium chloride; NaOCl: sodium hypochlorite; CHX: chlorhexidine; CHX-G: chlorhexidine gel; O3: ozonated water; CaOCl: calcium hypochlorite; NS: normal saline; EDTA: ethylenediaminetetraacetic acid; DS: distilled

water; MB: methylene blue; aPDT: antimicrobial photodynamic therapy; Er,Cr:YSGG: erbium chromium yttrium scandium gallium garnet; PCS: pulp canal sealer™ - cement based on zinc oxide and eugenol; AX: apexit- cement based on calcium

hydroxide; SS: root canal preparation with stainless steel instruments; NiTi: root canal preparation with K3® nickel titanium rotary instruments; SMP: scotchbond multi-purpose; EDP: ED primer; PaF: panavia; AH26: a resin-based sealer silver-

free Dentsply ®.

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Author (Year) Teeth origin n/Group of

teeth

Root canal treatment Preparation of glass ﬁber posts Bond strenght

test

Irrigation solutions groups during treatment

(n)

Final irrigation

solutions (n) Instrumentation Endodontic

sealer Drills used Glass ﬁber

posts cleaning

Adhesive sys-

tem/Sealer

Buenoetal.,

2016 [18] Bovine 96/Incisors

G1: NS + SMP + RelyX (n=8)

EDTA with

ultrasonic

vibration +

Same irrigant

solutions

Modiﬁed step-

back technique

with manual

K-type ﬁles.

AH Plus #5 Largo

70% alcohol and

37% phosphoric

Acid

G1-4: SMP +

RelyX

Push-out shear

test

G2: 2.5% NaOCl + SMP + RelyX (n=8) G5-8: EDP +

PaF

G3: 5.25% NaOCl + SMP + RelyX (n=8)

G9-12: U100

G4: 2% CHX + SMP + RelyX (n=8)

G5: NS + EDP + PaF (n=8)

G6: 2.5% NaOCl + EDP + PaF (n=8)

G7: 5.25% NaOCl + EDP + PaF (n=8)

G8: 2% CHX + EDP + PaF (n=8)

G9: NS + U100 (n=8)

G10: 2.5% NaOCl + U100 (n=8)

G11: 5.25% NaOCl + U100 (n=8)

G12: 2% CHX + U100 (n=8)

Kaif and Bis,

2016 [24] Human 30/Single-

rooted

G1: 5.25% NaOCl (n=10)

EDTA

Protaper nickel-

titanium rotary

instrumentation:

S1, S2, and F3.

AH Pus

#3 Gates-

Glidden

70% Isopropyl

alcohol

Adper Single

Bond 2 + RelyX

ARC

Push-out test

G2: 2% CHX (n=10) #5 Peeso

reamer

G3: DS (n=10)

Khoroushietal.,

2019 [20] Human 40/Premolars

G1: 0.9% NS (n=8)

Conventional

step-back

technique with

#35 K-ﬁle and

#2, #3 Gates-

Glidden.

AH26

#2 and #3

Gates-Glidden

drills

Alcohol

BisCem

self-adhesive

cement

Push-out test

G2: 2.5% NaOCl (n=8) G3: 5.25% NaOCl (n=8)

G4: 2,5% CaOCl (n=8) G5: 5% CaOCl (n=8)

Hashemetal.,

2021 [31] Human 60/C-shaped

Canal Molars

G1: aPDT 2% MB + diode laser (n=15)

Step-back

technique using

K-ﬁles and

#2, #3 and #4

Gates Glidden

Burs.

AH26 Peeso reamers 70% alcohol MD Push-out

G2: Er,Cr:YSGG laser (n=15)

G3: 2% CHX (n=15)

G4: 1.5% NaOCl (n=15)

Macedoetal.,

2021 [30] Bovine 77/MD

G1: 2.5% NaOCl (n=11)

The root canals

were prepared

by using a

high-precision

electric drill

with torque

control and a

2mm steel bit

Sealer 26 Gates-Glidden MD

Self-adhesive

cement RelyX

U200

Push-out

G2: DS (n=11)

G3: 2% CHX (n=11)

G4: O3 (n=11)

G5: 2.5% NaOCl + DS (n=11)

G6: 2.5% NaOCl + 2% CHX (n=11)

G7: 2.5% NaOCl + O3 (n=11)

free Dentsply ®.

Table II - Continued...

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

torque control [30]. Most studies used AH

Plus endodontic sealer to perform canal lling

together with gutta percha [18,21,24] (Table II).

Gates Glidden drills were used in

the preparation of glass fiber posts in four

studies [20,22,24,30]. However, one of these

studies associated Gates Glidden with the Peeso

Reamer [24], and one study used only the Peeso

Reamer [31]. Largo drill was used in three

studies [17,18,21] (Table II).

The majority of the studies used alcohol to

clean glass ber post [17,18,20,21,24,31], and

of these studies, two had associated the use of

alcohol with phosphoric acid [18,21] (Table II).

With regard to the adhesive system used for

the cementation of glass ber posts, two studies

used a two-step etch-rinse system [22,24], one

study used a two-step self-etching adhesive

system [21], and three studies used self-etching

and self-adhesive cements [17,20,30]. One study

used more than one adhesive system including

a three-step etch-rinse system, a two-step self-

etching system and self-etching and self-adhesive

cement [18] (Table II).

Regarding the bond strength tests of the glass

ber post to the root dentin, almost all studies have

perfomed push-out tests [17,18,20,24,30,31].

Of these, one study perfomed the push-out test

with and without articial accelerated aging [17],

while another study performed, in addition to the

push-out test, the shear bond strength test [18].

Only one study performed the micro-push-out

test [22], and one study performed the tensile

strength test [21] (Table II).

Four studies showed that the endodontic

substances used during treatment did not

influence the adhesion of the glass fiber

post to root dentin [18,21,22,24]. However,

Santana et al. [17] reported an increase in

bond strength when using sodium hypochlorite,

compared with ozonized water. Conversely, a

study by Macedo et al. [30] showed that 2.5%

sodium hypochlorite with ozonized water showed

better results in terms of its effect on bond strength.

Another study showed that specimens treated

with photodynamic therapy had the highest bond

strength with the fewest failures [31]. Although

the study by Khoroushi et al. [20] did not show

a statistically significant difference between

the other solutions, showed that the highest

bond strength was observed in the 5% calcium

hypochlorite group (Table III).

In relation to different concentrations of

sodium hypochlorite, two studies showed no

statistical differences in bond strength [20,21].

One study reported that sodium hypochlorite in its

most concentrated form (5.25%) had a signicant

adverse impact on bond strength, when combined

with RelyX U100 resin cement [18] (Table III).

Quality assessment

Four articles [20,24,30,31] were classied

as high risk of bias and the other four

articles [17,18,21,22] as medium risk of bias, as

shown in Table IV. None of the studies succeeded

in blinding of the operator of the testing machine,

nor performed the sample calculation, which is

considered the greatest difculty of the articles

in general.

Publication bias

Although the laboratory studies included

a small sample and no study performed an

adequate sample size calculation, there was less

publication bias due to the publication of both

positive and negative results for the questions

evaluated. In addition, these studies were not

funded by companies.

DISCUSSION

The teeth submitted to root canal treatment,

in the great majority, have a great loss of dental

structure, requiring glass ber posts to retain a

future restoration [11]. There is great clinical

concern regarding the inuence of endodontic

irrigation solutions on the bond strength of glass

ber posts to root dentin. In this review, only

eight studies [17,18,20-22,24,30,31] were found

that answered the question raised. The articles

have inconsistencies and different estimates

among themselves; in addition, few studies have

evaluated the different concentrations of sodium

hypochlorite, which is the most used endodontic

irrigation substance. Therefore, conclusive data

on this issue are lacking, with good studies

outlined and without methodological bias.

The evaluation of methodological quality

was perfomed with high rigor using an adapted

tool [27-29] for laboratory studies. The great

difculty of the articles was in performing blinding

of the testing machine operator, root canal

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Table III - Characteristics of bond strength tests from the included studies (n=8)

Author (Year) Groups (n) Bond strenght test Bond strenght values (Mean/SD) Results

NaOCl x Other irrigation solutions Diﬀerent concentrations of NaOCl

Pelegrineetal.,

2010 [21]

G1: 0.9% NaCl (n=10) Tensile strength test: an acrylic resin

cylinder ﬁtted on top with a metallic

loop was made over the coronal

portion of the post. After the resin was

polymerized, the test specimen was

placed in a Universal Testing Machine,

and an axial tensile load was applied at

0.5 mm/min until failure.

G1: 24.661±9.776

NaOCl did not reduce adhesion

compared with the groups irrigated

with chlorhexidine.

Diﬀerent concentrations of NaOCl

tested did not inﬂuence the tensile

bond strength of the adhesive system

used in this study to cement glass ﬁber

posts in root dentin.

G2: 1.0% NaOCl (n=10) G2: 28.537±11.704

G3: 2.5% NaOCl (n=10) G3: 27.537±9.681

G4: 5.25% NaOCl (n=10) G4: 25.572±8.801

G5: 2% CHX-G + 0.9% NaCl (n=10) G5: 28.831±9.389

Grassietal.,

2012 [22]

G1: 0.2% CHX + PCS (n=10) Micro-push-out test: it was performed

on a 3343 Instron Universal Testing

Machine with a load cell of 500 N. The

crosshead speed was set equal to 1

mm/min.

G1: 15.1±4.6 The interfacial shear strength values

do not seem to depend on the group

(irrigant/endodontic sealer) in which

the samples were classiﬁed, and no

statistically signiﬁcant diﬀerences were

observed.

________

G2: 5% NaOCl + PCS (n=10) G2: 14.1±4.4

G3: 5% NaOCl + AX (n=10) G3: 14.0±6.0

G4: 0.2% CHX + AX (n=10) G4: 16.8±5.4

Santanaetal.,

2015 [17]

G1: 1% NaOCl + SS + Immediate (n=10)

Push-out test: in immediate groups,

slices were submitted immediately to

a push-out test; while in aged groups,

slices were stored in distilled water at

37°C for 2 months (artiﬁcial accelerated

aging) prior to testing. The push-

out test was performed in a Testing

Machine by applying a compressive

load at 0.5 mm/min from the apical to

coronal direction until failure. The bond

strength was calculated in MPa by

dividing the load at failure (N) by the

area of the bonded interface.

G1: Cervical 12.9±2.4, Middle 10.3±4.0,

Apical 7.1±3.8

NaOCl resulted in higher bond

strength than with O3. CHX resulted

on intermediate values that were

statistically similar to values obtained

in groups irrigated with O3. Regardless

of irrigant solutions, cervical third

had higher bond strength values than

apical third. A signiﬁcant bond strength

increases after artiﬁcial accelerated

aging, except for middle and apical

thirds of SS-O3 and apical of NiTi-O3,

which was similar.

________

G2: 2% CHX + SS + Immediate (n=10) G2: Cervical 11.4±3.3, Middle 9.8±3.9,

Apical 6.7±3.9

G3: 1.2% O3 + SS + Immediate (n=10) G3: Cervical 8.7±6.8, Middle 6.2±5.0,

Apical 3.5±2.9

G4: 1% NaOCl + NiTi + Immediate

(n=10)

G4: Cervical 13.5±2.1, Middle 11.4±3.3,

Apical 9.3±4.8

G5: 2% CHX + NiTi + Immediate (n=10) G5: Cervical 11.5±3.8, Middle 10.0±4.9,

Apical 7.1±5.6

G6: 1.2% O3 + NiTi + Immediate (n=10) G6: Cervical 9.5±3.4, Middle 7.4±1.6,

Apical 6.8±1.4

G7: 1% NaOCl + SS + Aged (n=10) G7: Cervical 24.1±5.8, Middle 20.3±7.7,

Apical 15.5±8.6

G8: 2% CHX + SS + Aged (n=10) G8: Cervical 18.8±4.3, Middle 16.2±4.0,

Apical 13.3±7.2

G9: 1.2% O3 + SS + Aged (n=10) G9: Cervical 17.4±4.9, Middle 9.9±4.0,

Apical 6.4±3.4

G10: 1% NaOCl + NiTi + Aged (n=10) G10: Cervical 25.1±6.4, Middle 22.6±6.1,

Apical 21.6±6.3

G11: 2% CHX + NiTi + Aged (n=10) G11: Cervical 21.4±3.4, Middle 20.8±6.3,

Apical 18.4±7.7

G12: 1.2% O3 + NiTi + Aged (n=10) G12: Cervical 17.4±4.9, Middle 11.0±5.3,

Apical 7.1±3.8

NaCl: sodium chloride; NaOCl: sodium hypochlorite; CHX: chlorhexidine; CHX-G: chlorhexidine gel; O3: ozonated water; CaOCl: calcium hypochlorite; NS: normal saline; DS: distilled water; MB: methylene blue; aPDT: antimicrobial

photodynamic therapy; Er,Cr:YSGG: erbium chromium yttrium scandium gallium garnet; PCS: pulp canal sealer™ - cement based on zinc oxide and eugenol; AX: apexit- cement based on calcium hydroxide; SS: root canal preparation with

stainless steel instruments; NiTi: root canal preparation with K3® nickel titanium rotary instruments; SMP: scotchbond multi-purpose; EDP: ED primer; PaF: panavia; MPa: megapascals; N: Newtons.

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Author (Year) Groups (n) Bond strenght test Bond strenght values (Mean/SD) Results

NaOCl x Other irrigation solutions Diﬀerent concentrations of NaOCl

Buenoetal.,

2016 [18]

G1: NS + SMP + RelyX (n=8)

Push-out shear test: the specimens

obtained were identiﬁed and kept in

distilled water for 24 hours at 37°C

in containers that did not allow the

passage of light. An axial compressive

load of 100 N was applied to the apical

surface of the post section at a speed

of 1.0 mm/min until the cross section

of the post became separated from its

respective root section. The kilogram-

force values applied until separation

were divided by the root canal area to

convert results to MPa.

G1: 9.47±9.86

There was no statistically signiﬁcant

reduction in bond strength when

comparing the irrigants.

NaOCl in its more concentrated form

(5.25%) had a signiﬁcant adverse

impact on the bond of ﬁber posts luted

with RelyX U100 self-adhesive resin

cement to dentin.

G2: 2.5% NaOCl + SMP + RelyX (n=8) G2: 12.61±7.85

G3: 5.25% NaOCl + SMP + RelyX (n=8) G3: 13.92±4.77

G4: 2% CHX + SMP + RelyX (n=8) G4: 12.19±7.87

G5: NS + EDP + PaF (n=8) G5: 10.87±5.57

G6: 2.5% NaOCl + EDP + PaF (n=8) G6: 12.09±5.02

G7: 5.25% NaOCl + EDP + PaF (n=8) G7: 9.47±4.46

G8: 2% CHX + EDP + PaF (n=8) G8: 11.11±5.51

G9: NS + U100 (n=8) G9: 14.00±6.82

G10: 2.5% NaOCl + U100 (n=8) G10: 15.29±6.39

G11: 5.25% NaOCl + U100 (n=8) G11: 8.82±4.12

G12: 2% CHX + U100 (n=8) G12: 13.36±8.34

Kaif and Bis,

2016 [24]

G1: 5.25% NaOCl (n=10) Push-out test: the test specimen slices

were ﬁxed in the ﬁtting device ﬁtted to

the Universal Testing Machine. The 0.8-

mm diameter tip was placed over the

smallest base of the test specimen and

a compression force was applied in an

apical-coronal direction at a crosshead

speed of 0.5 mm/minute until the post

piece was dislocated. The peak value

of the load required for dislocating the

post from the specimen was recorded

in Newtons.

G1: 38.29±21.54

No signiﬁcant diﬀerences in bond

strength were found between the

groups.

________

G2: 2% CHX (n=10) G2: 38.95±12.16

G3: DS (n=10) G3: 39.60±14.76

Khoroushietal.,

2019 [20]

G1: 0.9% NS (n=8) Push-out test: it was carried out for

each section at a crosshead speed

of 0.5mm/minute using a Universal

Testing Machine. The maximum force

at the point where the post was

dislodged from the root section was

considered as the bond failure point

and was recorded in Newton. Then,

the push-out bond strengths were

calculated in MPa.

G1: 7.28±2.66

The highest bond strength belonged to

the 5% calcium hypochlorite group. There was no statistical diﬀerence.

G2: 2.5% NaOCl (n=8) G2: 8.15± 2.51

G3: 5.25% NaOCl (n=8) G3: 8.38±3.76

G4: 2,5% CaOCl (n=8) G4: 8.9±3.13

G5: 5% CaOCl (n=8) G5: 11.84± 2.04

stainless steel instruments; NiTi: root canal preparation with K3® nickel titanium rotary instruments; SMP: scotchbond multi-purpose; EDP: ED primer; PaF: panavia; MPa: megapascals; N: Newtons.

Table III - Continued...

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

Table III - Continued...

Author (Year) Groups (n) Bond strenght test Bond strenght values (Mean/SD) Results

NaOCl x Other irrigation solutions Diﬀerent concentrations of NaOCl

Hashemetal.,

2021 [31]

G1: aPDT 2% MB + diode laser (n=15) Push-out test: The roots submitted

to post cementation were sectioned

along the shaft using a low speed

diamond saw. The slices obtained from

the specimens were individually ﬁxed

in the Universal testing machine. The

push-out was calculated by dividing

the maximum failure load into Newtons

to surface area of connecting pin

segments in mm2.

G1: 8.56±2.12

The specimens treated with aPDT

showed the highest push out bond

strength with least number of failures

in c-shaped mandibular root canals.

________

G2: Er,Cr:YSGG laser (n=15) G2: 7.90±1.56

G3: 2% CHX (n=15) G3: 7.34±1.23

G4: 1.5% NaOCl (n=15) G4: 6.92±2.21

Macedoetal.,

2021 [30]

G1: 2.5% NaOCl (n=11)

Push-out test: The roots were ﬁxed

on a metallic base in the ISOMET

1000 stake machine and sectioned

perpendicularly along the root axis.

Three discs were sectioned for each

third (cervical, middle and apical). The

specimens

G1: Cervical 10.71±1.74, Medium

9.47±2.29, Apical 6.3±1.98

The sodium hypochlorite solution

showed a statistically similar behaviour

to the group of sodium hypochlorite

solution + ozonated water, the latter

being the best results in terms of its

eﬀect on the bond strength. Regardless

of root depth, the sodium hypochlorite

+ chlorhexidine solution group showed

the worst binding strength.

________

G2: DS (n=11)

were stored under relative humidity at

37°C for 7 days. And for the push-out

test, a metal cylinder was used to

induce a charge at the center part

of the post-cement set. The test

was carried out in a universal testing

machine.

G2: Cervical 8.05±, Medium 5.21±1.20,

Apical 3.18±1.36

G3: 2% CHX (n=11) G3: Cervical 8.09±1.21, Medium

4.88±1.12, Apical 3.82±1.29

G4: O3 (n=11) G4: Cervical 10.91±2.03, Medium

8.66±1.52, Apical 6.41±2.11

G5: 2.5% NaOCl + DS (n=11) G5: Cervical 8.44±2.17, Medium

6.57±1.48, Apical 5.69±1.36

G6: 2.5% NaOCl + 2% CHX (n=11) G6: Cervical 6.93±1.13, Medium

5.58±1.16, Apical 3.31±0.96

G7: 2.5% NaOCl + O3 (n=11) G7: Cervical 9.27±1.24, Medium

7.38±1.12, Apical 5.6±1.24

stainless steel instruments; NiTi: root canal preparation with K3® nickel titanium rotary instruments; SMP: scotchbond multi-purpose; EDP: ED primer; PaF: panavia; MPa: megapascals; N: Newtons.

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

treatment by a single operator, or calculation of

the sample in the research. These requirements

are extremely important and must be met to

reduce both imprecision and inconsistencies in

the scientic literature.

Human teeth are more reliable in terms

of bond strength, because they have the same

mineral composition that we deal with in clinical

management. However, some studies [17,18,21,30]

have used bovine teeth. Bovine teeth have

similarities in morphology to human teeth, less

variability of tissue permeability and internal

anatomy with the smallest variation and have

been used as a substitute for human teeth in bond

strength tests [4,32,33].

Chemical solutions used for disinfection,

cleaning, and completing of the mechanical

instrumentation process during root canal

treatment can cause physical and chemical

changes, such as decreased microhardness

and increased permeability of the root canal

dentin [34,35].

Sodium hypochlorite is the chemical substance

most commonly used in root canal treatment,

because of its antimicrobial power, as well as its

unique ability to dissolve remnants of necrotic

tissues [2]. However, it is noteworthy that sodium

hypochlorite decomposes into sodium chloride and

oxygen, and when there is oxygen in the surface

layer, there is an inhibition of the binding of resin

cement and dentin [36,37], which interferes

with the penetration of adhesive in the dentinal

tubules [38], impairing the bond strength. On the

other hand, chlorhexidine is a potent antiseptic

widely used in dentistry, and has also been used as

an endodontic irrigant solution at concentrations

of 0.2% to 2%. It inhibits the growth of bacteria

commonly found in endodontic infections [39], has

a residual effect [40], and has low cytotoxicity [41].

It has a harmless effect on the microhardness and

dentin roughness of the root canal [38], which can

result in greater bond strength.

However, most laboratory studies in this

review did not show the influence of such

substances on adhesion or on, different

concentrations of sodium hypochlorite. Only

one study [18] showed that the maximum

concentration of sodium hypochlorite (5.25%)

when associated with specific resin cement

(RelyX U100) reduced the bond strength. One of

the reasons for this the double polymerization

reaction of the resin cement. Calcium phosphates

are formed as part of the reaction with hard

tissues [42]. These low-energy bonds, along

with the surface oxidation caused by sodium

hypochlorite and the diffusion of by-products into

the dentin, may have inhibited polymerization

at the interface between dentin and cement,

resulting in lower strength values [18], signaling

that future studies are needed to investigate the

possible mechanisms of interaction between

endodontic irrigants and RelyX U100.

New therapeutic approaches have been used

to help reduce endodontic infection [43-47],

despite controversies in the literature, and brings

in vogue the concern of the performance of these

Table IV - Quality assessment methodological of included studies (n=8)

Teeth

randomization

Materials used

according to the

manufacturer’s

instructions

Teeth with

similar

dimensions

Root canal

treatment

performed

by a single

operator

Standardization

of procedures

Sample size

calculation

Blinding of

the operator

of the testing

machine

Risk of bias

Pelegrineetal.,

2010 [21] Yes Yes Yes Yes Yes No No Medium

Grassietal.,

2012 [22] Yes Yes No Yes Yes No No Medium

Santanaetal.,

2015 [17] Yes Yes Yes No Yes No No Medium

Buenoetal.,

2016 [18] Yes Yes Yes Yes Yes No No Medium

Kaif and Bis,

2016 [24] No Yes No No Yes No No High

Khoroushietal.,

2019 [20] Yes No Yes No Yes No No High

Hashemetal.,

2021 [31] Yes Yes No No Yes No No High

Macedoetal.,

2021 [30] No Yes Yes No Yes No No High

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

substances in the adhesion of glass ber posts.

Hashem et al. [31] showed that aPDT with a

methylene blue photosensitizer showed the

highest bond strength with the lowest number

of failures in C-shaped mandibular root canals.

Santana et al. [17] showed lower results in

adhesion when using ozonated water, contrary

to the study by Macedo et al. [30], which showed

better results, showing the need for further

studies to reduce these inconsistencies.

In this review, the most commonly used nal

irrigant was EDTA [17,18,21,24], a chelating

agent that acts on the inorganic portion of

the dentin, exposing the dentinal tubules, by

removing the smear layer [48]. However, in

this systematic review, in relation to the nal

irrigation with EDTA, the studies did not show

signicant results for bond strength. A greater

possibility of compacting the smear layer in the

dentinal tubules occurs during the shaping of

the root canal, which can act as a barrier to the

penetration and interaction of cement with the

intraradicular dentin, which may be related to the

decrease in adhesion strength [17]. Therefore, the

use of chelators in the nal irrigation is important

for providing greater adhesion strength.

In the same context, sterile saline solution

or distilled water can be used as an aid in nal

endodontic irrigation, or among the main

irrigants chosen. However, these substances

should not be used as main irrigants, as they

have neither tissue-dissolving nor antimicrobial

activity. These substances act by neutralizing the

solutions used during root canal treatment, thus

helping to increase bond strength [49].

Cleaning of the glass ber posts did not show

a pattern among the included articles. This can be

an important reason for bond strength, because

Kaif and Bis [24] showed that the most prevalent

failure observed was at the interface between the

post and resin cement, which was attributed to the

chemical interactions between the outer layer of

the glass ber post and the cementing agent, such

as cleaning the surface with 70% alcohol, 37%

phosphoric acid or applying silane or ceramics,

which should be the subject of future studies.

An important fact to be analyzed is the

adhesive system and/or resin cements used to

x the glass ber posts. Most studies have used

adhesive systems to cement glass fiber posts.

However, half articles [17,18,20,30] used self-

etching and self-adhesive resin cement in their

study groups, which is a material that offers

resistance bonding similar to multi-step resin

cements without the need for acid, primers or

adhesives. This can have a great inuence on the

bond strength, making it higher, because they

have indications for union with several substrates,

in addition to a chemical and mechanical

interaction, which could mask the inuence of

endodontic irrigation solutions.

Another topic on which studies diverge is the

bond strength test, which can be an important

issue in evaluation. This shows the lack of

standardization among the surveys, as there is no

standard test for this type of assessment, which

may have inuenced the differences in outcomes.

Although the present study was a review

of laboratory studies, it is strongly relevant

to daily clinical approaches. This is because

glass ber posts play an important role in the

restoration of endodontically treated teeth and

irrigation solutions are essential for successful

root canal cleaning. To ensure the methodological

quality of this systematic review, several criteria

were rigorously followed, such as independent

evaluations, broad electronic search with no date

or language limit, grey literature search, and

manual search. However, this study had some

limitations. First, an adapted instrument was

used to perform the quality assessment, as there

was no specic tool for this type of laboratory

study. Second, the heterogeneity of the studies,

such as the different substances used during

treatment, or even the different concentrations of

the irrigants, different bond strength test methods

and different types of root canal instrumentation,

made it difcult to compare the studies and did

not allow the performance of the meta-analysis.

Therefore, the heterogeneity between the

studies did not allow a comparison for a true

estimate, requiring well-designed future studies

to clarify this issue and reinforce all the variables

that may inuence the adhesion of glass ber

posts to root dentin.

CONCLUSION

It was concluded that the included studies

reported conflicting results regarding the

inuence of irrigating solutions and the different

concentrations of NaOCl used during root canal

instrumentation in the adhesion of glass ber

posts to the root dentin. Therefore, new studies

Braz Dent Sci 2023 July/Sept;26 (3): e3856

Reys IG et al.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review

Reys IG et al. Do irrigation solutions used during root canal instrumentation

inﬂuence the adhesion of glass ﬁber posts? A systematic

review

are encouraged to help more assertively in the

decision of professionals on this topic that is so

common in clinical reality.

Author’s Contribution

IGR, LSG, LSDT, MRRC, LAAA, LSA:

Conception. IGR, LSG, MRRC: Manuscript

Writing. IGR, LSG: Literature Search. IGR,

LSG: Critical Evaluation of Studies and Data

Extraction. LSA: Responsible for Consensus in

Disparities. IGR, LSG, LSDT, MRRC, LAAA, LSA:

Critically Reviewing the Final Draft of the Paper.

Conict of Interest

No conicts of interest declared concerning

the publication of this article.

Funding

The work was supported by individual

scholarships (FAPERJ - Fundação de Amparo

à Pesquisa do Estado do Rio de Janeiro [#E-

26/010.100995/2018; #E-26/202.805/2019;

#E-26/010.002195/2019; #E-26/204.402/2021;

#E-26/200.199/2023], CNPQ (Conselho Nacional

de Desenvolvimento Cientíco e Tecnológico). This

study was also nanced in part by the Coordenação

de Aperfeiçoamento de Pessoal de Nível Superior

- Brasil (CAPES) - Finance Code 001.

Regulatory Statement

This systematic review was conducted

through a search strategy in electronic databases.

The search was restricted to publications in

peer-reviewed journals, dissertations or theses,

in which approval for ethics committee were

obtained in their original work.

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Leonardo Santos Antunes

(Corresponding address)

Universidade Federal Fluminense, Curso de Odontologia, Departamento de

Formação Especíca, Nova Friburgo, RJ, Brazil

e-mail: leonardoantunes@id.uff.br

Date submitted: 2023 Apr 07

Accept submission: 2023 June 15