Current trends in irrigant activation techniques among Brazilian endodontists: a cross-sectional survey

Abstract

Aim  This cross-sectional study aimed to evaluate the knowledge, acceptance, and use of irrigant activation techniques during root canal treatment (RCT) among Brazilian endodontists.

Methods  Participants received an electronic questionnaire consisting of 16 questions regarding sociodemographic characteristics, professional profile, and irrigation protocols. Responses were collected from June 2022 to October 2023. Data were analyzed descriptively and using Chi-square tests at a 5% significance level.

Results  A total of 282 endodontists responded to the survey. Most were female (61.3%), with an average of 14.5 years since dental school graduation and 10.2 years of specialized training in endodontics. Most respondents were from the southern (49.6%) and southeastern (32.3%) regions. Of them, 44.3% worked exclusively in private practice and 31.6% combined private practice with academic roles. Sodium hypochlorite (75.9%) and EDTA (92.9%) were the predominant irrigants used during RCT. When asked to rank the reasons for their primary irrigant selection, antimicrobial capability was considered the most important and to clean isthmuses and ramifications, the main reason to use activation methods. In total, 78.3% of respondents consistently used irrigant activation, with 69.5% employing it after chemomechanical preparation. Passive ultrasonic irrigation was the most popular technique, followed by the Easy Clean instrument. Workplace setting significantly influenced the frequency of irrigant activation usage (p<0.05).

Conclusion  In conclusion, most Brazilian endodontists employ irrigant activation techniques and prefer sodium hypochlorite and EDTA as irrigating solutions, aligning their practices with global standards. This web-based survey highlights the integration of contemporary scientific knowledge into endodontic practice.

Keywords
Endodontics; Root canal irrigants; Surveys and questionnaires

Introduction

Root canal treatment (RCT) has undergone continuous evolution over the years. When Schilder described the principles for cleaning and shaping root canals, the primary goal was to prepare a continuously tapered canal to receive a three-dimensional and hermetic filling that would contribute to the success of this therapy¹. Nowadays, the focus on RCT is intricately associated with an efficient disinfection while preserving as much cervical and radicular dentin as possible in order to maintain the root structure, mitigating the risk of dental fractures and subsequently tooth loss².

The irrigation stage plays a pivotal role in root canal disinfection³. A systematic review of micro-computed tomography studies⁴ showed that, irrespective of the kinematics and file used, unprepared areas persist on the radicular surface. Furthermore, root canal anastomoses present challenges to achieving proper disinfection of the root canal system⁵. In these confined areas, the cleaning will be dependent on the irrigant used and the way it is delivered into the canal².

Syringe irrigation remains the most popular technique for delivering irrigants during RCT³. This method appears to be quite effective in the main root canal when the proximity of the needle to the apical terminus is reached³,⁶. However, in this conventional approach, the established flow cannot penetrate very far inside anatomic irregularities such as fins⁷,⁸, isthmuses⁹ and lateral canals¹⁰.

Irrigant activation techniques have emerged to enhance cleaning efficacy, particularly in cases with more complex anatomies³, and also to compensate the shorter irrigant action time resulting from modern RCT, which are often conducted with fewer instruments or even with a single file³. Despite the range of activation techniques available, there is still limited knowledge regarding which methods are the most widely accepted and employed by endodontists, both in Brazil and worldwide. Prado et al.¹¹(2018) explored the most commonly used irrigating solutions in Brazil through an online questionnaire but did not investigate the use of adjunct activation devices. In contrast, studies by Dutner et al.¹²(2012) in the United States and Natanasabapathy et al.¹³(2020) in India examined irrigant activation protocols used by endodontists in their respective regions. Therefore, the aim of this cross-sectional survey was to determine the current trends in irrigant activation techniques among Brazilian endodontists.

Methodology

This study was approved by the Ethics Research Committee of the Federal University of Santa Maria, Santa Maria, RS, Brazil (CAAE: 50465821.1.0000.5346; approval protocol number 4.973.708). All participants provided electronic informed consent prior to participation.

The sample for this study consisted of Brazilian dentists with specialized training in endodontics. The specialization status of the participants was self-reported and the registration status with Regional Dental Councils was not independently verified. The sample size calculation was conducted with an online sample size tool (Roasoft Inc., Seattle, WA, USA), considering the parameters described by Virdee et al.¹⁴(2020) and an estimated population of 16,658 Brazilian endodontists. As no previous data is available on several of the questions included in this survey, an expected outcome of 50% was assumed. Therefore, to achieve a confidence level of 90%, with a 5% error margin, a minimum of 267 responses were required.

The questionnaire was developed on the Google Forms platform (Figure 1). In a pilot study, a preliminary version was sent by e-mail to a sample of 10 endodontists from the Post-Graduate Program in Dental Sciences at the Federal University of Santa Maria, to pretest the questionnaire in terms of wording, sequence, and internal consistency. Additionally, it was possible to estimate the content validity, i.e. if the questions were considered relevant to assess the current practices of the respondents. These aspects were not assessed quantitatively, but the questions were revised and edited based on feedback. The final questionnaire was distributed along with an explanatory cover letter elucidating the aims of the project.

Figure 1
The questionnaire sent to Brazilian endodontists.

From June 2022 to October 2023, professional email addresses were identified through structured Google searches using Portuguese terms related to endodontics. Searches targeted publicly available sources such as personal practice websites, institutional pages, and professional profiles. Before distribution, addresses were organized and de-duplicated to ensure only one contact per individual. In addition, endodontics faculty members and postgraduate program coordinators were directly contacted and asked to forward the standardized invitation to eligible colleagues and trainees within their networks. The same invitation and survey link were disseminated via WhatsApp and posted in Brazilian Facebook groups dedicated to endodontics. Furthermore, an Instagram account (@pesquisaendoufsm) was created to extend dissemination through posts and stories. No nominative follower data were collected, and platform engagement metrics were not used to estimate the number of invitees.

Each participant received an invitation, containing project information and the estimated time spent to answer the questions. The invitation also included a link redirecting to the questionnaire hosted on the Google Forms platform. By clicking to accept the informed consent form on the initial page, the individuals had the freedom to decide whether they wished to proceed with their participation and answer the questionnaire. They were able to use the device of their choice (computer, tablet or smartphone). Additionally, a reminder e-mail or message, sent two weeks apart, aimed to increase the response rate.

Participants answered 16 questions, both open-ended and closed. The first part of the questionnaire gathered information about their sociodemographic characteristics and professional background. The second part focused on their clinical approach during RCT and the use of irrigant activation techniques.

Furthermore, no participant received any kind of incentive or prize, as all participants were volunteers. This questionnaire was adapted from previous surveys conducted by Dutner et al.¹²(2012), Natanasabapathy et al.¹³(2020) and Bolfoni et al.¹⁵(2018).

A specific email address was created to enhance data control and individuality. Also, the survey was developed according to the Checklist for Reporting Results of Internet E-surveys (CHERRIES), which is part of the EQUATOR network (Enhancing the QUAlity and Transparency Of health Research)¹⁶.

Descriptive analysis was conducted, and the data were expressed in terms of absolute and relative frequencies or mean and standard deviation (SD). The Chi-square test was used to explore potential associations. Data analysis was carried out using Microsoft Office Excel (Microsoft Corp., Redmond, WA, USA) and SPSS (version 29.0; SPSS Inc., Chicago, IL, USA) software programs. The significance level was set at 5%.

Results

In total, 282 individuals provided valid responses to the online questionnaire. The response rate was not calculated since it was not possible to determine precisely how many endodontists received or accessed the e-mails and invitations on social media. Nevertheless, this sample (n=282) represents about 1,7% of the Brazilian endodontists registered in the Regional Dental Councils. Table 1 summarized the characteristics of the sample.

Table 1
Sample characteristics (n = 282).

	n (%)
Gender
Female	173 (61.3)
Male	109 (38.7)
Time since graduation [mean(±SD)]
Dental school Graduation	14.5 (±9.99)
Specialized training in Endodontics	10.2 (±8.98)
Brazilian territorial regions
Southern	140 (49.6)
Southeastern	91 (32.2)
Northeastern	27 (9.6)
Central-western	17 (6.0)
Northern	7 (2.5)
Workplace
Private practice	125 (44.3)
Private practice + graduate or undergraduate professor	89 (31.6)
Graduate or undergraduate professor	37 (13.1)
Private practice + public institutions	12 (7.1)
Public institutions	11 (3.9)

• SD: Standard-deviation.

Table 2 presents the key findings regarding irrigants and activation methods. Most participants (78.3%) reported always using some form of irrigant activation during endodontic treatment. Among those who occasionally or never use activation, the main reasons cited were the time required for the procedure (11.3%, n=32), treating teeth with incomplete root development or resorptions (2.1%, n=6), lack of available agitation devices in the workplace (1.8%, n=5), the perceived high cost of the procedure (1.1%, n=3), skepticism about its impact on success rates (0.7%, n=2), insufficient knowledge (0.7%, n=2), and treating teeth with a vital pulp (0.3%, n=1). Regarding the stage of RCT in which activation is applied, 69.5% (n=196) reported using it after the chemomechanical preparation (CMP).

Table 2
Irrigants and activation techniques used by Brazilian endodontists (n = 282).

	n (%)
Main irrigant
Sodium hypochlorite	214 (75.9)
Chlorhexidine	42 (14.9)
Sodium hypochlorite + Chlorhexidine	26 (9.2)
Continue
Continuation
Final irrigant
EDTA	262 (92.9)
Citric acid	10 (3.5)
Other solutions	6 (2.1)
None	4 (1.5)
Frequency of irrigant activation usage
Always	221 (78.3)
Sometimes	58 (20.6)
Never	3 (1.1)
Stage of irrigant activation usage
After CMP	196 (69.5)
During and after CMP	73 (25.9)
During CMP, between instrument changes	10 (3.5)
Never	3 (1.1)

• CMP: chemomechanical preparation.

When asked to rank the reasons for their primary irrigant selection, antimicrobial capability was considered the most important, followed by tissue dissolution, biocompatibility, substantivity and expense (Figure 2).

Figure 2
Factors influencing primary irrigant selection. Participants in the survey were asked to rank the reasons (antimicrobial capacity, tissue dissolution, biocompatibility, substantivity and expense) they considered most (first) to least (fifth) important.

Respondents also reported the main reasons for using irrigant activation methods. Cleaning isthmuses and ramifications of the main root canal was the most cited motive, reported by 89% (n=251) of the respondents, followed by debris and smear layer removal, antimicrobial capacity, tissue dissolution and enhancing irrigant properties (Figure 3).

Figure 3
Reasons for employing irrigant activation methods. Survey respondents were asked to select the reason they considered most important for using irrigant activation techniques (cleaning isthmuses and ramifications, debris and smear layer removal, antimicrobial capacity, tissue dissolution and enhancing irrigant properties).

When asked if irrigant activation enhances disinfection and cleaning of the root canal system, 70% (n=197) strongly agreed with this statement (Figure 4A). Similarly, when asked if irrigant activation could increase the success rate of RCT, 59% (n=165) strongly agreed with this affirmative (Figure 4B).

Figure 4
(A) Frequency (%) of answers about irrigant activation techniques and the enhancement of cleaning and disinfection. (B) Frequency (%) of answers about irrigant activation techniques and success rate.

Concerning the irrigant activation techniques, the question allowed multiple choices, so several participants selected more than one method. Passive ultrasonic irrigation (PUI) was the most cited technique (66%), followed by Easy Clean (61%) (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) and manual dynamic activation (21%) (Figure 5). The remaining participants reported using XP-Endo Finisher (16%), XP-Clean (12%) or other instruments (6%), such as EndoActivator, Lentulo spiral, Laser, etc.

Figure 5
Most cited irrigant activation techniques among Brazilian endodontists.

Table 3 describes possible associations between several variables, such as gender, years since dental school graduation, years since specialized training conclusion, Brazilian region and workplace setting and the consistent use of irrigant activation. Years since graduation and since specialized training were dichotomized at the sample median (12 and 8 years, respectively) to create approximately balanced strata for chi-square tests, given the absence of clinically stablished cutoffs. Among all these variables, only the workplace, where the respondent exerts clinical practice, was significantly associated with the frequency of irrigant activation usage (P<0.05).

Table 3
Associations between the consistent use of irrigant activation techniques and sociodemographic or professional variables.

		Irrigant activation usage		P-value*
		Always N (%)	Sometimes/never N (%)
Gender	Female	135 (78)	38 (22)	0.86
	Male	86 (78.9)	23 (21.1)
Time since graduation**	≤ 12 years	110 (75.3)	36 (24.7)	0.20
	> 12 years	111 (81.6)	25 (18.4)
Time since specialized training**	≤ 8 years	113 (74.3)	39 (25.7)	0.07
	> 8 years	108 (83.1)	22 (16.9)
Brazilian region	South	107 (76.4)	33 (23.6)	0.55
	Southeast	71 (78)	20 (22)
	Midwest	13 (76.5)	4 (23.5)
	Northeast	23 (85.2)	4 (14.8)
	North	7 (100)	0 (0)
Workplace	Private practice	89 (71.2)	36 (28.8)	0.02
	Private and public practices	14 (70)	6 (30)
	Private practice and education	80 (89.9)	9 (10.1)
	Education	29 (78.4)	8 (21.6)
	Public sector	9 (81.8)	2 (18.2)

• *Chi-square test (P<0.05).
• **Cutoffs based on the sample median.

Discussion

Both the European Society of Endodontology (ESE) and the American Association of Endodontics (AAE) recommend, in their guidelines, the use of some form of irrigant activation during chemomechanical preparation¹⁷,¹⁸. Therefore, understanding the clinical routine of endodontic specialists is a way to ascertain if what is studied and discussed in scientific literature is reaching those who provide assistance to the population. Through this research, it was observed that 78.3% of the respondents reported always using irrigant activation methods, suggesting that Brazilian endodontists stay updated and align their practices with evidence-based dentistry. A similar study conducted in the United States (US), in 2012, reported that slightly less than half of the respondents used some form of irrigant agitation at that time¹². In a questionnaire administered to Indian endodontists in 2020, 87.3% reported using activation techniques¹³.

Sodium hypochlorite emerged as the most frequently mentioned irrigant (75.9%), followed by chlorhexidine (14.9%). This prevalence can be attributed to the widespread endorsement of sodium hypochlorite in endodontic treatments³, driven by its favorable chemical properties as outlined in several studies¹⁹-²¹. A similar finding was reported by Natanasabapathy et al.¹³(2020), where 77.8% of Indian endodontists reported using sodium hypochlorite. Dutner et al.¹²(2012) found that 91% of American endodontists use this irrigant, while in the United Kingdom and Ireland, Virdee et al.¹⁴(2020) revealed that 93.7% of general dental practitioners use hypochlorite as the primary irrigant during RCT.

Additionally, when asked about the reasons for choosing the main irrigant, respondents stated that antimicrobial capacity and tissue dissolution are the main considerations, both of which are properties found in sodium hypochlorite. The same sequence of reasons for choosing the main irrigant was reported by American endodontists¹². For smear layer and debris removal, 92.9% of participants reported the use of EDTA. This practice is consistent with the observations of Moss et al.²²(2001), who found that 80% of American endodontists also employ this substance prior to obturation. Using a chelating substance to enhance the effectiveness of intracanal medications and the quality of obturation is well-established in the endodontic literature³.

When asked if irrigant activation enhances disinfection and cleaning of the root canal system, 70% of the respondents strongly agreed with this statement, and regarding irrigant activation increasing the success rate, 59% strongly agreed with this affirmative. It is well known that the success rate of endodontic treatment is closely related to the disinfection of the root canal system, especially in cases of apical periodontitis²³,²⁴. Although robust evidence from large randomized clinical trials demonstrating that irrigant activation increases the success rate is lacking²⁵, experimental studies suggest that irrigant activation can improve root-canal cleanliness under controlled conditions³,²⁶,²⁷. However, findings are heterogeneous and derive from in vitro and ex vivo models.

Regarding the irrigant activation techniques chosen by Brazilian endodontists, the majority of the respondents indicated PUI or Easy Clean. PUI, recognized as the “gold standard” in agitation studies, is also the most commonly employed method among American endodontists¹³ and their Indian counterparts¹⁴. Easy Clean, on the other hand, is a low-cost instrument developed by a Brazilian industry. It is crafted from acrylonitrile butadiene styrene plastic, featuring a 25/0.04 size and an aircraft wing-shaped cross-section. Originally, it was developed to operate in a reciprocating motion in endodontic motors. However, recent studies demonstrate better debris removal when it is used in continuous rotation, coupled to a micromotor and contra-angle, in low speed, prompting the manufacturer to adjust its protocol²⁶,²⁸,²⁹.

This study found an association between the use of irrigant activation techniques and the workplace setting. Respondents working simultaneously in private practice and as professors reported the highest prevalence of consistent irrigant activation usage (89.8%, n=80). These clinical practices are generally run by the specialist dentists themselves, allowing them to invest in advanced equipment and instruments, which ultimately enhances the quality of their daily work. In contrast, clinicians employed in the Brazilian public healthcare system often face challenges in accessing high-quality materials, but the use of manual dynamic activation with a file or gutta-percha point is a viable alternative⁸.

Social networking services have become a compelling tool for conducting research and disseminating relevant information in the contemporary world³⁰,³¹. Using a self-administrated questionnaire has the potential to reach a substantial sample size, covering a broad geographical area and diverse population. With this in mind, this research provided important insights into how endodontics is practiced in Brazil. However, because part of the dissemination relied on Facebook, Instagram and WhatsApp, the exact reach of the invitations could not be precisely determined, which may have led to potential selection and coverage bias favoring professionals more active on these platforms.

While the precise number of endodontists who received the link invitation to participate remains unknown, it is worth noting that response rates for this type of study tend to be low³²,³³. While the study findings may not be directly generalized to all endodontists, the number of responses obtained here was comparable to that observed in other countries¹³. In addition, it was not possible to independently verified the specialist registration with the Regional Dental Councils (the status was self-reported). Although unlikely, this limitation cannot be entirely excluded as a source of misclassification or selection bias.

The study successfully reached all Brazilian territorial regions. However, a notable concentration of respondents is evident in the southern region of the country (49.4%), where the researchers are based. These results can be explained by the unequal distribution of dentists across the Brazilian territory, with a higher concentration of professionals in the South and Southeast regions³⁴. Another explanation is that, despite the use of an easily accessible tool that only requires a computer or a mobile device with internet access, the barrier of networking may have influenced response rates in more distant areas. This fact does not invalidate the results obtained here. Surveys with health questionnaires are of paramount importance in profiling the investigated population. Through this methodology, we can gather data on perceptions, trends, and opinions of a segment of individuals of interest³⁵.

This national survey describes self-reported preferences and practices regarding irrigant activation among Brazilian endodontists. The vast majority of the Brazilian endodontists have incorporated some form of irrigant activation technique into their endodontic treatments, with PUI and Easy Clean being the most commonly used methods. Similar to practices in other countries, sodium hypochlorite and EDTA stand out as the most frequently used auxiliary chemical substances. Future prospective and randomized studies are warranted to determine whether these reported practices translate into relevant benefits for patients.

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• Data availability:
  Datasets related to this article will be available upon request to the corresponding author.

Edited by

• Editor:
  Dr. Altair A. Del Bel Cury

Data availability

Datasets related to this article will be available upon request to the corresponding author.

Publication Dates

• Publication in this collection
  24 July 2026
• Date of issue
  2026

History

• Received
  22 Apr 2025
• Accepted
  26 Oct 2025