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Year : 2023  |  Volume : 26  |  Issue : 2  |  Page : 143-149
Comparative analysis of reduction in pain scores after single visit root canal treatment using endodontic irrigation protocols, namely, Conventional needle irrigation, PUI, PIPS and SWEEPS: A randomized control trial

Department of Conservative Dentistry and Endodontics, FODS, BHU, Varanasi, Uttar Pradesh, India

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Date of Submission08-Aug-2022
Date of Decision09-Nov-2022
Date of Acceptance01-Dec-2022
Date of Web Publication16-Mar-2023


Introduction: To assess the effects of different irrigation activation systems on postoperative pain using a Visual Analog Scale (VAS), using new laser irrigation activation system shock wave-enhanced emission photoacoustic streaming (SWEEPS), photon-induced photoacoustic streaming (PIPS), passive ultrasonic irrigation activation techniques, compared with the conventional irrigation (CI) method.
Materials and Methods: Sixty patients suffering from symptomatic irreversible pulpitis in maxillary or mandibular molars were enrolled and randomly assigned to four different irrigation activation groups (n = 15) after chemomechanical root canal preparation. Preoperative and postoperative pain scores were recorded using VAS. The data were collected and subjected to statistical analysis using IBM SPSS 20.0 software at a level of significance being 0.05.
Results: We observed that mean pain scores decreased with time in all patients in all groups. The decrease in pain score was found to be statistically significant (P < 0.05) among both the genders in Group 3 (PIPS) and Group 4 (SWEEPS). Postoperatively, pain scores decreased significantly using Group 4 (SWEEPS), followed by Group 3 (PIPS), Group 2 (ultrasonic activation), and Group 1 (conventional needle irrigation). No significant relation was observed statistically between pain scores and age groups among all groups, except for preoperative score in Group 3 and age groups.
Conclusion: Postoperative scores were lower in laser-activated irrigation systems as compared to the other activation systems. The highest pain scores were observed in case of CI method, at pre- and post-operative periods.

Keywords: Conventional irrigation; Irrigation systems; Pain; PIPS; SWEEPS; Ultrasonic activation

How to cite this article:
Mittal N, Baranwal HC, Gupta S, Shankari T, Gupta S, Kharat S. Comparative analysis of reduction in pain scores after single visit root canal treatment using endodontic irrigation protocols, namely, Conventional needle irrigation, PUI, PIPS and SWEEPS: A randomized control trial. J Conserv Dent 2023;26:143-9

How to cite this URL:
Mittal N, Baranwal HC, Gupta S, Shankari T, Gupta S, Kharat S. Comparative analysis of reduction in pain scores after single visit root canal treatment using endodontic irrigation protocols, namely, Conventional needle irrigation, PUI, PIPS and SWEEPS: A randomized control trial. J Conserv Dent [serial online] 2023 [cited 2023 May 28];26:143-9. Available from:

   Introduction Top

After endodontic treatment, postoperative pain is a common redundant sensation, with an incidence rate of 3%–58%. Various factors have been found to be associated with pain after root canal treatment (RCT). Pain can result from chemical, mechanical, and/or microbial injury to pulpal or periradicular tissues. Endodontic research has revealed that it is very difficult to completely eliminate the bacterial biofilm from the root canals due to various factors.[1]

The root canal irrigation is a crucial step that helps in the removal of organic and inorganic debris, disinfecting root canal system, and lubricating canal during instrumentation. However, it has been found that no commercially available irrigant can meet the requirements of an ideal irrigant. Irrigation solution alone is not enough to efficiently clean the untouched areas of root canal. Thus to reduce or eliminate bacterial biofilm, different disinfecting devices have been developed.[2] These devices are the irrigation activation systems, that increase the removal of debris and smear layer by enhancing the efficiency of the irrigation solutions.[3] The different activation systems are manual, syringe and needle, canal brushes, sonic, ultrasonic, and laser systems.[4],[5]

It is important to consider the appropriate instruments, method, irrigant, and activation systems to prevent the postoperative pain. Conventional irrigation (CI) method involves the application of irrigant through a syringe with a needle of different tip designs and diameters. CI technique is incompetent in cleaning the inaccessible areas such as isthmus and apex, as penetration of irrigant is limited up to 0–1.1 mm beyond the tip of the needle. Thus, different irrigation activation methods have been developed that help in improving the efficacy of irrigants.[6]

A passive ultrasonic irrigation system works on the principle of acoustic streaming and irrigant cavitation by transmitting the acoustic energy into the root canal through a smooth wire or an oscillating file to the irrigation solution. The laser activation system is based on the activation of the irrigant using a laser, either in pulp chamber or root canal. The photon-induced photoacoustic streaming (PIPS) is the technique used in the pulp chamber, but efficient extrusion of debris still remains controversial.[7] To increase the efficacy of PIPS technique, shock wave-enhanced emission photoacoustic streaming (SWEEPS) model was developed.[8]

This randomized clinical trial was conducted to assess and compare the efficacy of different irrigation activation methods in terms of postoperative pain after RCT.

   Materials and Methods Top

This randomized controlled trial was conducted in the department of conservative dentistry and endodontics, for 6 months from February 2021 to June 2022. The study protocol was approved by the Institutional Ethics Committee (Dean/2021/IEC/2698). The clinical trial was registered with a clinical trial registry (CTRI/2021/07/045781).

The null hypothesis of the study was that there would be no statistically significant difference between the pain prevalence of different irrigation activation methods, including conventional, ultrasonic and laser systems, after RCT.

Sample size calculation

On the basis of results of a pilot study, G * Power 3.1 software (Heinrich Heine University, Dusseldorf, Germany) was used to calculate the sample size required for the study. The minimum sample size required was calculated as 60 (n = 15) based on the F-test family, 0.56 effect size, 0.05 alpha type error, and 0.95 power.

Eligibility criteria

The Consolidated Standards of Reporting Trials guidelines were followed at the time of starting the study [Figure 1]. After obtaining the ethical committee and clinical trial approval, a total of 60 patients were selected from the outpatient department of the faculty of dental sciences, department of conservative dentistry and endodontics, based on the inclusion and exclusion criteria.
Figure 1: CONSORT 2010 flow diagram

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Inclusion criterion

Patients aged 18–44 years with no gender predilection, having moderate-to-severe pain in multi-rooted posterior teeth having either continuous or spontaneous, radiating or throbbing nature with nocturnal incidence were selected. All teeth responding to cold pulp sensibility tests with an exaggerated response or pain with/without lingering were included in the study.

Exclusion criterion

Patients suffering from any systemic condition, or periapical bone changes evident on the preoperative periapical radiographs were excluded from the study. Patients having a history of consumption of any medication for pain in the previous 10 days were excluded from the study.

This selection was followed by thorough intraoral and radiographic assessments of permanent teeth. A written informed consent was obtained from all patients.

Root canal treatment procedures

All 60 patients with prolonged responses to cold test in posterior multi-rooted teeth were equally divided into four irrigation groups. The computer-based simple random sampling method ( was used for randomization, which was done by a researcher who was not part of the study. Double blinding was done, in which both operator and patients were unaware of the group assigned. The irrigation activation method was made aware to the operator at the time of phase.

All selected patients were randomly divided into four study groups: Group 1 (conventional needle irrigation), Group 2 (ultrasonic activation), Group 3 (PIPS), and Group 4 (SWEEPS). These patients were further divided into subgroups according to their age and sex. Age subgroups were ≤24, 25–34, and 35–44.

A trained single endodontist performed all the RCT s of the patients after administration of local anesthesia (2.5 mL of 2% lignocaine with 1:80000 adrenaline–Lignox) and isolating the tooth with rubber dam. Before anesthesia, the patients indicated the intensity of their pain using Visual Analog Scale (VAS) score (0–10) by choosing a number using the following values: levels 0–3, mild pain, levels 4–7, moderate pain, and levels 8–10 and severe pain. Access cavities were prepared using sterile diamond and carbide burs. Working length was assessed using an electronic apex locator, Root ZX Mini Apex Locator (J Morita, Japan). Hyflex EDM (Coltene) files were used for root canal preparation according to the manufacturer's instructions with canalPro endomotor (Coltene).

Root canal was lubricated and smear layer management was done using Ethylenediaminetetraacetic acid (EDTA) (10%) and carbamide peroxide (15%) (Endoprep RC, Anabond Stedman Pharmaceuticals, India). In all groups, 2 ml of saline with 2% povidone-iodine was used as the initial irrigant and this was followed by the sodium hypochlorite, and EDTA, as mid-rinses using 1 ml for each canal, followed by 2 ml of 2% chlorhexidine as last irrigant.

A 29-G side vented (NaviTip; Ultradent, South Jordan, UT) irrigation needle was used for conventional needle-syringe irrigation (CI) method (Group 1). The process of recapitulation was done at each file change with a size #10 K-file. In Group 2, the irrigation solution was activated using an ultrasonic tip (Ultra X tips; Eighteeth) to an ultrasonic device (Ultra X; Eighteeth, Orikam). The activation of the tip was activated for around three times, with each cycle for 20 s along involving the use of 1 ml of 3% NaOCl. Two milliliter of 17% EDTA solution was then activated for 1 min. Without touching the canal walls, the ultrasonic tip was placed 2 mm short of the working length of canal.

In Group 3, the conical fiber PIPS tip (600 μm diameter and 9 mm long polyamide sheathed quartz) was attached to the Er: YAG laser (LightWalker, Fotona, Ljubljana, Slovenia) at the wavelength of 2,940 nm adjusted at 20 mJ per pulse, 15 Hz, 0.3 W power, and 50 μs pulse frequency by keeping it stable in the access cavity. Activation of 3% NaOCl solution was done in three cycles of 20 s. Then, the procedure was repeated with 2 ml of 17% EDTA solution. In Group 4, the SWEEPS fiber tip (25 μs ultra-short dual pulse mode-Auto SWEEPS mode) was attached into the Er: YAG laser source (at 2,940 nm wavelength, 20 mJ per pulse, 15 Hz, 0.3 W power, and 50 μs pulse frequency). The SWEEPS tip was placed in a stable position in the access cavity and activation was done by activating solutions in the same way as for the PIPS group.

Then, a final irrigation of each canal was performed with 2 mL of 2% chlorhexidine solution. After completion of the root canal preparation, apical patency was checked using a size 10 K-file (Mani Co., Tokyo, Japan).

The root canal fillings were done using single cone gutta-percha points (Roeko Hyflex EDM Gutta-Percha Points, Coltene) with zinc oxide eugenol-based cement (Prime Dental Products Thane, India). A postoperative radiograph was taken to ensure that root canals were adequately filled up to the working length, with no extrusion of filling material into the periapical tissues.

Analgesics (sos) were prescribed but the patients were advised to only take them in the event of significant pain. The postoperative pain levels and the need for analgesics were recorded after 24 and 48 h by telephoning each patient to question them.

   Results Top

Among 60 patients, 28 and 32 were males and females respectively, males being 7 and females being 8 in each of the four groups. Mean pre- and post-operative pain scores were recorded at 24 and 48 h, respectively. Patients with pain score more than 4 took analgesics as prescribed. Pain score was more in females than males in all the groups, in preoperative and postoperative score. It was observed that mean pain scores decreased with time in all patients of all groups [Table 1]. Independent t-test was done to evaluate the correlation between both the genders in relation to pain at all time periods.
Table 1: Intergroup comparison in relation to pain scores at pre- and post-operative time periods between all groups using one-way ANOVA statistical analysis

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Mean pain scores were recorded for all the study groups at pre- and post-operative time periods. Intergroup comparison was done using one way analysis of variance (ANOVA) statistical analysis. On comparing postoperative pain scores among all the groups at both time periods, we found a significant difference (P < 0.05) between all study groups. Post hoc statistical analysis revealed that pain score decreased significantly in Group 4 (SWEEPS), followed by Group 3 (PIPS), Group 2 (ultrasonic activation), and Group 1 (conventional needle irrigation) [Table 1].

Decrease in the pain score was found to be statistically significant (P < 0.05) among both the genders in Group 3 (PIPS) and 4 (SWEEPS) at 48 h [Table 2]a. Mean pain scores for all study groups in relation to different age groups were recorded. The level of significance in terms of pain scores related to age groups was assessed using ANOVA statistical analysis. It was observed that mean pain score was least in 35–44 years of age group, followed by 25–34 years, <24 years, and above 45 years of age in all study groups. No significant relation was observed statistically between pain scores and age groups among all groups, except for preoperative score in Group 3 and age groups [Table 2]b.

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   Discussion Top

Root canal irrigation is a critical step in effectual cleaning and disinfection of root canals. To enhance the affectivity of irrigant, activation of irrigation solutions has been commonly used. Postoperative pain commonly occurs due to extrusion of debris due to different irrigation techniques.[9] Main factor causing pain is the inflammatory response due to injury to the periapical tissues. Thus, the present study was conducted to assess and compare the postoperative pain caused by different irrigation activation systems; ultrasonic, PIPS and SWEEPS with CI.

In the present study, we used multi-rooted maxillary and mandibular teeth due to difficulty in finding extra root canals, complex pulpal anatomy, and extrusion of irrigants from apex of root. Various studies have been conducted on multi-rooted teeth.[10],[11],[12]

Working length determination is the crucial step as it can cause extrusion of debris, leading to postoperative pain.[13] In our study, we used both apex locators and radiographic methods to determine working length efficiently. We performed single visit RCT, to reduce the possibility of loss of follow-up. It has been reported by various authors that analgesic use is higher in single visit than multi-visit RCT.[14],[15]

There are various methods that help in evaluating the postoperative pain, but we used VAS score, as it is easy to understand and assess. Various authors have advocated the use of VAS pain score for evaluating pain.[9],[16] We compared the pain scores preoperatively and postoperatively in all groups, for both the genders and all age groups. The results of our study rejected null hypothesis as we found significant differences statistically between pre- and post-operative pain in all study groups. Our study revealed that SWEEPS technique was highly effective, as pain decreased significantly postoperatively, followed by PIPS and ultrasonic activation.

The results can be explained by escalated disinfection using laser-assisted endodontic procedure. In PIPS is achieved through absorption of short(50 μs) Er: YAG laser pulse in the irrigant, which initiates rapid increase in temperature and formation of vapor bubble.[1],[3] These bubbles expands and collapses after reaching maximum volume, thus creating pressure on surrounding liquid. Wherein, The Sweeps modality delivers Super-Short Pulse (25 μs) pulsed frequency into the liquid which imitates growth of second bubble before explosion of the first one, which in turn accelerating the collapse of initial bubble.[4] The procedure enables primary and secondary shock waves to be generated throughout the root canal system.

We observed that females were having more pain scores at all time intervals and in all study groups as compared to males. The difference of pain between both the genders was not significantly different except in Groups 3 and 4 at 48 h. The results of our study were in accordance with study by Gündoğar M et al.[17] who also found that perception of pain was more in females than males during endodontic treatment.

It has been advocated that sex hormones have a considerable impact on variability to perceive pain by both men and women. This is because of different distribution of sex hormones and their receptors present in the peripheral and central nervous systems that are linked to pain transmission. The effect of estradiol and progesterone hormones on sensitivity of pain is a complex mechanism. They have pronociceptive and antinociceptive effects on pain. Testosterone have more antinociceptive effect and is protective in nature than progesterone.[18]

Results of our study were in accordance with study conducted by Erkan et al.[3] except that their study concentrated on multiple visit RCT. Various studies have supported the affectivity of lasers with irrigation systems in disinfecting and eliminating Enterococcus feacalis in infected root canals.[19],[20] Some studies reported that extrusion of debris was minimum with laser-assisted irrigation activation, thus reducing postoperative pain.[21],[22]

We observed that CI produced significantly more pain as compared to ultrasonic and laser irrigation activation systems. The oscillatory movement in ultrasonic system pushes the irrigants[23] laterally to the canal walls, whereas with CI with syringe, irrigants constantly move apically.[24] This causes irrigants to extrude apically, leading to increased incidence of postoperative pain.

Limitations of study

  1. The study used randomization and double blinding techniques, but during procedure both operators and patients got aware of the method being used. This was due to difference of equipments being used during the procedure. This might have led to varied pain perception responses by the patients
  2. The present study was conducted as a pilot study with a limited sample size. Further studies should be conducted with larger sample size to validate the results
  3. Pain is a subjective parameter, so variation in pain perception and anxiety among the patients can lead to information bias. VAS score used in the study can be used only in written format and is not ideal for telephonic interviews. Patients too face some difficulty in finding the best score that applies to them, i.e., justifying the significance of pain with verbal score


  1. Future studies should be conducted with larger sample size, and longer follow-up period
  2. Further research is required to assess and compare the pain perception using irrigation activation techniques between single- and multi-rooted teeth
  3. Better measures than pain perception scales should be used to estimate pain
  4. Future studies should be conducted to evaluate other mechanical irrigation activation devices.

Till date only limited studies are available that assessed laser assisted irrigation activation evaluated PIPS and SWEEPS.[3],[22] Thus, our study highlights the need of irrigation activation systems during endodontic procedure and advocate the use of good irrigation activation methods that can reduce postoperative pain.

   Conclusion Top

Within the limitations of the current study, it has been observed that laser-assisted irrigation activation systems were very efficient in preventing and limiting pain after RCT. We should avoid using CI as it causes higher grade of pain as compared to irrigation activation methods.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Dedania MS, Shah NC, Shah R, Bhadra D, Bajpai N, Pisal N, et al. Passive ultrasonic irrigation and laser disinfection on postoperative pain in single visit RCT. J Clin Diagn Res 2021;15:ZC33-6.  Back to cited text no. 1
Tinaz AC, Alacam T, Uzun O, Maden M, Kayaoglu G. The effect of disruption of apical constriction on periapical extrusion. J Endod 2005;31:533-5.  Back to cited text no. 2
Erkan E, Gündoğar M, Uslu G, Özyürek T. Postoperative pain after SWEEPS, PIPS, sonic and ultrasonic-assisted irrigation activation techniques: A randomized clinical trial. Odontology 2022;110:786-94.  Back to cited text no. 3
Mancini M, Cerroni L, Palopoli P, Olivi G, Olivi M, Buoni C, et al. FESEM evaluation of smear layer removal from conservatively shaped canals: Laser activated irrigation (PIPS and SWEEPS) compared to sonic and passive ultrasonic activation-an ex vivo study. BMC Oral Health 2021;21:81.  Back to cited text no. 4
Srinivasan S, Kumarappan SK, Ramachandran A, Honap MN, Kadandale S, Rayar S. Comparative evaluation of pulp tissue dissolution ability of sodium hypochlorite by various activation techniques: An in vitro study. J Conserv Dent 2020;23:304-8.  Back to cited text no. 5
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Hızarcı U, Koçak S, Saglam BC, Koçak MM. Comparison of different irrigation activation techniques on postoperative pain after endodontic treatment: A randomized clinical trial. Turk Endod J 2022;7:7-12.  Back to cited text no. 7
DiVito E, Peters OA, Olivi G. Effectiveness of the erbium: YAG laser and new design radial and stripped tips in removing the smear layer after root canal instrumentation. Lasers Med Sci 2012;27:273-80.  Back to cited text no. 8
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Gupta NK, Mantri SP, Paul B, Dube KA, Ghosh S. Incidence of postoperative pain after single-visit and multiple-visit root canal therapy: A randomized controlled trial. J Conserv Dent 2021;24:348-53.  Back to cited text no. 14
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Olivi G, DiVito E, Peters O, Kaitsas V, Angiero F, Signore A, et al. Disinfection efficacy of photon-induced photoacoustic streaming on root canals infected with Enterococcus faecalis: An ex vivo study. J Am Dent Assoc 2014;145:843-8.  Back to cited text no. 20
Shaktawat AS, Verma KG, Goyal V, Jasuja P, Sukhija SJ, Mathur A. Antimicrobial efficacy of 980 nm diode laser on Enterococcus feacalis in conjunction with various irrigation regimes in infected root canals: An in vitro study. J Indian Soc Pedod Prev Dent 2018;36:347-51.  Back to cited text no. 21
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Vidas J, Snjaric D, Braut A, Carija Z, Persic Bukmir R, De Moor RJ, et al. Comparison of apical irrigant solution extrusion among conventional and laser-activated endodontic irrigation. Lasers Med Sci 2020;35:205-11.  Back to cited text no. 23
Jiang LM, Verhaagen B, Versluis M, van der Sluis LW. Influence of the oscillation direction of an ultrasonic file on the cleaning efficacy of passive ultrasonic irrigation. J Endod 2010;36:1372-6.  Back to cited text no. 24

Correspondence Address:
Dr. Sakshi Gupta
Department of Conservative Dentistry and Endodontics, FODS, BHU, Varanasi, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jcd.jcd_450_22

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