doi:10.1111/j.1365-2591.2010.01721.x

Efficacy of syringe irrigation, RinsEndo and passive ultrasonic irrigation in removing debris from irregularities in root canals with different apical sizes

T. Ro¨dig1, M. Sedghi2, F. Konietschke3, K. Lange3, D. Ziebolz1 & M. Hu¨lsmann1 1

Department of Preventive Dentistry, Periodontology and Cariology, University of Go¨ttingen, Go¨ttingen; 2Private Dental Practice, Fulda; and 3Centre for Statistics, University of Go¨ttingen, Go¨ttingen, Germany

Abstract Ro¨dig T, Sedghi M, Konietschke F, Lange K, Ziebolz D, Hu¨lsmann M. Efficacy of syringe irrigation, RinsEndo and passive ultrasonic irrigation in removing debris from irregularities in root canals with different apical sizes. International Endodontic Journal, 43, 581–589, 2010.

Aim To compare of the efficacy of syringe irrigation, RinsEndo (Du¨rr Dental, Bietigheim, Germany) and passive ultrasonic irrigation (PUI) in the removal of dentinal debris from simulated irregularities in root canals with different apical sizes. Methodology Thirty extracted human pre-molars were randomly divided into three groups (n = 10) followed by root canal preparation with rotary FlexMaster NiTi instruments (VDW, Munich, Germany) to size 30, 0.02 taper (group 1), size 40, 0.02 taper (group 2) or size 50, 0.02 taper (group 3). The teeth were split longitudinally, and a standard groove and three hemispherical-shaped cavities were cut into the root canal halves. Grooves and cavities were filled with dentinal debris before each irrigation procedure and the root halves were reassembled. In all groups three

Introduction Disinfection of the root canal system using antimicrobial and tissue-dissolving irrigants is considered as an

Correspondence: T. Ro¨dig, Department of Preventive Dentistry, Periodontology and Cariology, University of Go¨ttingen, Robert-Koch-Str. 40, 37075 Go¨ttingen, Germany (Tel.: +49 551 39 22 877; fax: +49 551 39 22 037; e-mail: [email protected]).

ª 2010 International Endodontic Journal

different irrigation procedures were performed with 30 mL NaOCl (1%) and (i) syringe, (ii) RinsEndo and (iii) PUI. The amount of remaining debris was evaluated under a microscope with 30· magnification and a four score system. The data were analysed with a nonparametric analysis of covariance and multiple comparisons using the Tukey adjustment (P = 0.05). Results Passive ultrasonic irrigation removed debris significantly better from the artificial canal irregularities than RinsEndo and syringe irrigation irrespective of the root canal diameter. Only in group 1 (30, 0.02 taper) the difference between PUI and RinsEndo was not statistically significant (P = 0.99). RinsEndo demonstrated significantly better results than syringe irrigation in all groups (P < 0.001). Conclusions Ultrasonic irrigation is more effective than syringe irrigation or RinsEndo in removing debris from artificial extensions in straight root canals. Keywords: debris, irrigation, RinsEndo, root canal, ultrasonic. Received 11 December 2009; accepted 19 February 2010

essential part of chemo-mechanical debridement (Haapasalo et al. 2005). Irrigation is complementary to instrumentation in facilitating the removal of bacteria, debris and necrotic tissue (Lee et al. 2004a), especially from areas that are routinely left uninstrumented following root canal preparation, e.g. isthmuses, oval extensions and apical deltas (Wu & Wesselink 2001, Peters 2004). It has been demonstrated that debris accumulation is a potential side effect of root canal instrumentation (Paque´ et al. 2009), and that

International Endodontic Journal, 43, 581–589, 2010

581

Removal of debris Ro¨dig et al.

accumulated debris certainly has a negative impact on the sealing ability of root canal fillings (De Deus et al. 2008), but it also may impede disinfection in cases with apical periodontitis (Nair et al. 2005, Haapasalo et al. 2007). Sodium hypochlorite is recommended as the main irrigant during root canal treatment (Zehnder 2006) because of its broad antimicrobial efficacy (Ørstavik & Haapasalo 1990, Spratt et al. 2001) as well as its unique tissue-dissolving capacity (Grossman & Meiman 1941, Naenni et al. 2004). Nevertheless, NaOCl is not able to dissolve the inorganic components of dentine debris (Goldman et al. 1981), and it was stated that removal of debris relies mostly on the flushing action of the irrigant (Lee et al. 2004b, van der Sluis et al. 2005b). Conventional manual irrigation with a syringe and needle remains widely accepted (Peters 2004), and its flushing action is dependent on many factors such as the insertion depth and diameter of the needle (AbouRass & Piccinino 1982, Chow 1983, Hsieh et al. 2007) and the final size and taper of the prepared root canal (Lee et al. 2004b, Falk & Sedgley 2005, Huang et al. 2008). It has been demonstrated that the flushing action of syringe irrigation to remove debris from root canal irregularities is not sufficient (Cunningham et al. 1982, Wu & Wesselink 2001, Lee et al. 2004a, Gu et al. 2009). Enhancement of the flushing action of irrigant solutions by ultrasound is well documented (Stock 1991, Lumley et al. 1993, Huque et al. 1998, van der Sluis et al. 2007a). During ultrasonic irrigation, the energy of a freely oscillating file is transmitted to the irrigant in the root canal resulting in acoustic streaming (Ahmad et al. 1987a,b, 1988, Lumley et al. 1991, Ahmad et al. 1992, Roy et al. 1994). The term ‘passive ultrasonic irrigation’ (PUI) was first described by Weller et al. (1980) and describes the non-cutting action of the ultrasonic file during irrigation to avoid aberration of root canal anatomy (van der Sluis et al. 2007a). Several authors concluded that ultrasonic irrigation has the potential to remove dentine debris and organic tissue from inaccessible root canal areas (Metzler & Montgomery 1989, Lee et al. 2004a, Gutarts et al. 2005, Passarinho-Neto et al. 2006, Al Jadaa et al. 2009). Recently, a novel device for root canal irrigation has been introduced (RinsEndo; Du¨rr Dental, Bietigheim, Germany). It represents an automated irrigation technique using combined irrigation and suction under hydrodynamic pressure. The irrigant is agitated to an oscillation of approximately 1.6 Hz. Until now, only a few studies have been published on this device. It has

582

International Endodontic Journal, 43, 581–589, 2010

been shown ex vivo that RinsEndo was more effective in the removal of pulp tissue compared to conventional static irrigation (Braun et al. 2005). Hauser et al. (2007) concluded that the penetration depth of a coloured irrigant into root canal dentine was higher for RinsEndo in comparison with syringe irrigation demonstrating the efficacy of the oscillation in distribution of the irrigant. In addition, RinsEndo was found to be significantly more effective in removing a bio-molecular collagen film than static syringe irrigation ex vivo (McGill et al. 2008). However, the same authors stated that RinsEndo was significantly less effective than dynamic manual irrigation. The aim of this study was to compare the efficacy of syringe irrigation, RinsEndo and PUI in the removal of dentinal debris from simulated root canal irregularities in root canals prepared to different master apical file sizes.

Material and methods The experimental design is based on the study by Lee et al. (2004a) and has been used in several investigations on the removal of debris (van der Sluis et al. 2005a,b) or calcium hydroxide (van der Sluis et al. 2007b).

Preparation of specimens Forty-five extracted human pre-molar teeth with single straight root canals, intact apices and no previous endodontic treatment were collected and stored in tap water throughout the study. After preparation of the access cavity, the length of the tooth was measured by inserting a size 10 stainless-steel file (VDW, Munich, Germany) into the root canal until the tip of the instrument was just visible at the apical foramen. Root canals allowing introduction of an instrument exceeding size 20 were excluded. The remaining 38 teeth were decoronated to obtain a standardized root length of 17 mm with a working length of 16 mm. The specimens were randomly divided into three groups followed by standardized root canal preparation with FlexMaster rotary NiTi instruments (VDW) to different sizes at working length. In group 1 (n = 13) the root canals were prepared to size 30, 0.02 taper, in group 2 (n = 12) to size 40, 0.02 taper and in group 3 (n = 13) to size 50, 0.02 taper. After each instrument change, manual irrigation was performed with 2 mL NaOCl (1%), using a syringe and a 30-gauge needle (NaviTip; Ultradent, South Jordan, UT, USA). Two grooves

ª 2010 International Endodontic Journal

Ro¨dig et al. Removal of debris

were cut along the long axis of each root using a diamond disc (Horico, Berlin, Germany). Subsequently, the roots were split longitudinally using a waxing instrument (Le Cron; Aesculap, Tuttlingen, Germany). For simulation of uninstrumented canal extensions, according to Lee et al. (2004a), a standard groove of 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut into one half of each root canal 2–6 mm from the apex using a modified round bur (Hager & Meisinger, Neuss, Germany). In the root canal wall of the other half, three standard hemispherical-shaped cavities, each 0.3 mm in diameter and 0.5 mm in depth, were cut at 2, 4 and 6 mm from the apex. Following the careful removal of debris from the root halves using a toothbrush, the specimens were embedded in acrylic resin (Paladur; Heraeus, Hanau, Germany) to seal the apical foramen and to facilitate reassembly. To take digital photographs before and after irrigation from identical angles the specimens were placed into silicone (Silaplast; Dentax, Ettlingen, Germany). The photographs were taken using a microscope (MOTIC Ergonomic Trinokular Zoom Stereo Mikroskop; Motic, Wetzlar, Germany) with 30· magnification and a digital camera (Moticam 1300; Motic) with a resolution of 1.3 megapixel. Dentine debris was produced by mixing 100 mg dentine chips with 0.175 mL NaOCl (1%) to achieve a wet sand-like consistency. Using a size 08 stainless-steel instrument (VDW), the grooves and hemisphericalshaped cavities were filled loosely with debris to simulate a clinical situation when dentine debris accumulates in uninstrumented root canal extensions. Subsequently, the root halves were reassembled and fixed using a clamp. Roots that could not be reassembled without gaps visible under a microscope at 30· magnification were discarded, resulting in a final number of 30 teeth with 10 specimens per group.

Irrigation procedures In all three main groups (n = 10) three different irrigation techniques were performed with 30 mL NaOCl (1%). The 10 teeth of groups 1, 2 and 3 were used three times to provide the following subgroups. The root canals in subgroup A were irrigated for 4.5 min with a syringe and a 30-gauge needle (NaviTip, Ultradent). The delivery rate was approximately 6.6 mL min)1. In subgroup B the irrigant was delivered and agitated by activation of the RinsEndo handpiece (Du¨rr Dental) using the needle provided by the manufacturer (needle size 45 with a lateral opening

ª 2010 International Endodontic Journal

of 7 mm). The delivery rate was set by the manufacturer at 6.2 mL min)1 resulting in an irrigation time of 4.8 min. The compressed air pressure supplying the handpiece was adjusted to 3.5 bar to ensure it was within the recommended range (2.3–4.2 bar). In subgroup C irrigation was performed with an ultrasonic device (Piezon Master 400; EMS, Nyon, Switzerland) and a stainless-steel K-type file size 15 (Endosonore; Maillefer, Ballaigues, Switzerland) with its power set at the ¼ of the scale. The root canals were irrigated during PUI for 3 min with a continuous flush of the irrigant (10 mL min)1). Ultrasonic irrigation in all groups was performed last as this technique is the only one that might result in alteration of root canal shape and size. In all specimens the irrigation devices were introduced into the root canals as far apically as possible until binding occurred followed by a 1 mm withdrawal to facilitate an outward flow of the irrigant or to allow free oscillation of the ultrasonic file during PUI, respectively. Consequently, the NaviTip needle and the ultrasonic file were placed 1 mm short of the working length in all groups. The RinsEndo irrigation needle was introduced in group 1 (30, 0.02 taper) 7 mm, in group 2 (40, 0.02 taper) 3 mm and in group 3 (50, 0.02 taper) 1 mm before working length. After the irrigation procedure the root halves were separated to take digital photographs of the canal walls. The remaining debris was removed from the grooves and cavities followed by a complete refilling of the artificial root canal extensions prior to the next irrigation procedure. All measures were carried out under a microscope at 30· magnification.

Scoring procedure The photographs before and after irrigation were coded to prevent identification of the experimental group. The amount of remaining debris in the groove and the hemispherical-shaped cavities was scored under the microscope with 30· magnification by two calibrated dentists using a scoring system described by van der Sluis et al. (2007b) (Fig. 1). A higher score indicated a larger amount of debris: score 0: the entire groove or cavity is empty; score 1: less than half of the groove or the cavity is filled with debris; score 2: more than half of the groove or the cavity is filled with debris; score 3: the entire groove or cavity is filled with debris. The average score of the three hemisphericalshaped cavities was used as the debris score for each specimen.

International Endodontic Journal, 43, 581–589, 2010

583

Removal of debris Ro¨dig et al.

(a)

(b)

measure based on the ranks of the data, it ranges between 0 and 1 and the higher the value the better. For the computation of the relative effects and the Pvalues both the SAS procedures PROC RANK, PROC MIXED and the SAS-macro F1_LD_F2 were used (Brunner & Langer 1999). If the interaction between two factors was significant, the analysis had to be split by one of the factors. The pairwise comparisons were adjusted for multiple testing according to Tukey with a level of significance of P = 0.05.

Results

(c)

(d)

Figure 1 Standardized debris score for grooves and hemi-

spherical-shaped cavities according to van der Sluis et al. (2007b). (a) score 0; (b) score 1; (c) score 2; (d) score 3. Original magnification ·30.

Calibration of the two scoring dentists before main evaluation of the specimens was performed with 150 root halves. After scoring, the results were discussed using reference photographs followed by the same procedure on 50 specimens. Five days later again 50 specimens were scored by both investigators. Intraindividual reproducibility and interindividual agreement were calculated.

Statistical analysis For the analysis sas 9.2 (SAS institute Inc., Cary, NC, USA) was used. Because the response is a score, a normal distribution cannot be assumed. For this reason analysis was performed with the aid of relative effects. The relative effect is a non-parametric comparing

584

International Endodontic Journal, 43, 581–589, 2010

During the complete scoring procedure the inter- and intra-individual difference in scoring never exceeded one score. Interindividual agreement was 96% in the first scoring; the final agreement was 98%. Intraindividual reproducibility was 98% for both investigators. The results of the scoring procedure are presented in Fig. 2. The multiple non-parametric model showed significant single statistical effects for irrigation technique (P < 0.0001) and root canal half (P < 0.0001). A significant interaction between the irrigation technique and the apical size (P = 0.0246) was found. PUI removed debris significantly better from the artificial canal irregularities than RinsEndo and syringe irrigation irrespective of the root canal diameter. Only in group 1 (size 30, 0.02 taper) the difference between PUI and RinsEndo was not statistically significant (P = 0.99). In group 2 (size 40, 0.02 taper) and group 3 (size 50, 0.02 taper) RinsEndo was significantly less effective than PUI (P < 0.001, P < 0.0174). RinsEndo demonstrated significantly better results than syringe irrigation in all groups (P < 0.001). In all groups the grooves were significantly cleaner than the hemispherical-shaped cavities (group 1: P < 0.0001, group 2: P = 0.0379, group 3: P = 0.0369). Disregarding the significant interaction, the efficacy of debris removal was not influenced by the size of the apical preparation (P > 0.05). Moreover, stratified by irrigation technique, in group 1 (size 30, 0.02 taper), RinsEndo was significantly more effective than in group 2 (size 40, 0.02 taper) (P < 0.05) whereas the difference between group 1 and 3 and group 2 and 3 was not significant (P > 0.05). However, because of the inferences, these secondary questions need further evaluation. None of the specimens irrigated with a syringe showed completely clean artificial root canal irregularities without any remaining debris (score 0). Debris was

ª 2010 International Endodontic Journal

Ro¨dig et al. Removal of debris

Evaluation of debris removal in group 1 (size 30/0.02)

(a) 30

24

26

24

Frequency

Syringe 20

RinsEndo® PUI

12 12 12 10 4

4 2

0

Score 0

Score 1

Score 2

0

Score 3

Evaluation of debris removal in group 2 (size 40/0.02)

(b)

28

30

Frequency

0

0

28

20

Syringe

15 10

13 12

RinsEndo® PUI

12

10

0

0

2

0

0

0 Score 0

Score 1

Score 3

Evaluation of debris removal in group 3 (size 50/0.02)

(c) 30

26 23

22 Frequency

Score 2

20

Syringe

16 14

14

RinsEndo® PUI

10 2

0

3 0

0

0

0 Score 0

Score 1

Score 2

Score 3

Figure 2 Frequencies of pooled evaluations for ‘investigator’

and ‘root half’ for group 1 (a), group 2 (b) and group 3 (c).

completely removed after irrigation with RinsEndo in 46% of the specimens and after PUI in 67% of the specimens.

Discussion The design of this study is comparable to that described by Lee et al. (2004a) and seems well suited to evaluate the removal of artificial dentine debris from the root canal. A similar experimental set-up also has been used by van der Sluis et al. (2005b, 2006) to investigate the efficacy of ultrasonic irrigation to remove debris from artificial grooves. In contrast, other studies investigated the cleanliness of the complete root canal wall after sonic and ultrasonic irrigation (Sabins et al. 2003) or the use of a brush-covered irrigation needle (Zmener et al. 2009). The advantage of this model is that the grooves and cavities contained comparable amounts of

ª 2010 International Endodontic Journal

debris before irrigation, as assessed by the initial scoring. Previous studies investigated the amount of debris only after irrigation (Abbott et al. 1991, Lumley et al. 1993) assuming an equal preoperative quantity of debris. This means that the effectiveness of different irrigation techniques in these studies may not have been evaluated correctly (Lee et al. 2004a). The scoring system used already had been described by van der Sluis et al. (2007b). Following thorough calibration, interindividual agreement and intra-individual reproducibility of 98% could be shown. Statistical evaluation revealed no significant influence of the observer (P = 0.9854) demonstrating a valid scoring system. The purpose of the study was to compare the efficacy of three irrigation techniques in removing debris. Thus, the same 10 teeth of each group were used three times to exclude potential variables such as root canal morphology. Because the oscillating file may cut the root canal wall, ultrasonic irrigation was always performed as the last irrigation procedure. In this study, 30 mL of NaOCl was used during every irrigation procedure to simulate a clinical situation where 10 instruments are used for preparation with 2 mL of irrigant delivered after every instrument change (Walters et al. 2002) followed by a final flush of 10 mL (Santos et al. 1999). This volume is in line with other investigations on the efficacy of root canal irrigation (Baumgartner et al. 1984, Baumgartner & Mader 1987, Scelza et al. 2000, Brito et al. 2009). Lee et al. (2004a) reported that ultrasonic irrigation removed debris more effectively from the grooves, whereas less debris remained in the depressions after syringe irrigation. In this study, the grooves were significantly cleaner than the hemispherical-shaped cavities regardless of the irrigation technique and despite the fact that one groove contained more debris than three cavities. The longitudinal grooves exhibited a larger surface area to the irrigant than the hemispherical-shaped cavities, assuming that hydrodynamic effects contributed to a more efficient cleaning of the grooves. There are only a few studies that evaluated the effectiveness of irrigation in root canals with different tapers (Lee et al. 2004b, van der Sluis et al. 2005b, Huang et al. 2008) or with different master apical file sizes (Khademi et al. 2006, Hsieh et al. 2007, Huang et al. 2008). Lee et al. (2004b) and van der Sluis et al. (2005b) performed PUI with a continuous flow of NaOCl (2%) in each root canal. From their results it can be concluded that within certain limits (size 20, 0.04 taper to 0.10 taper) the greater the taper the more

International Endodontic Journal, 43, 581–589, 2010

585

Removal of debris Ro¨dig et al.

debris can be removed from longitudinal grooves in the apical half. This indicates that a certain amount of root canal enlargement is necessary to allow sufficient irrigation. In addition, Huang et al. (2008) reported that a larger apical size allowed better apical flushing by the irrigant and that a larger taper provided better irrigant exchange between apical and coronal root canal areas. Khademi et al. (2006) showed that an apical instrumentation to a size 30 file with 0.06 coronal taper is effective for penetration of irrigants to the apical third. In this study, the efficacy of PUI and syringe irrigation in terms of debris removal was not influenced by the size of the apical preparation. A reason may be that it was possible to insert the needle and the ultrasonic file to 1 mm short of working length in all groups, which allowed delivery of the irrigant to the apical area. These findings support previous observations that the penetration depth of the irrigation needle has an impact on the fluid distribution (Hsieh et al. 2007), the mechanical efficacy of irrigation (Sedgley et al. 2005) and the removal of debris (Abou-Rass & Piccinino 1982, Chow 1983). In this study, during PUI there was a continuous flow of irrigant in the pulp chamber; therefore, the differences between the studies of Lee et al. (2004b) and van der Sluis et al. (2005b) can be explained by the fact that a taper could have an influence on the flow coronallyapically, more than the apical size. However, it was also stated that larger-sized apical preparations have a positive impact on the mechanical efficacy of root canal irrigation (Ram 1977, Abou-Rass & Piccinino 1982, Chow 1983, Wu & Wesselink 1995, Huang et al. 2008), which is not in line with this study. Of course, size of apical enlargement may influence not only hydrodynamics of the irrigant but also may have some impact on the chemical effects, i.e. that frequent exchange of irrigant might increase antimicrobial and tissue-dissolving capacity. These controversial results may be attributed to the differences regarding the experimental set-up, e.g. the use of larger irrigation needles with greater distances to the apex or smaller root canal preparations. The manufacturer’s instruction for RinsEndo suggests that the apical third of the root canal is effectively irrigated although the needle tip is inserted just into the coronal third because of the hydrodynamic activation of the irrigant, which is confirmed by this study. It was demonstrated that RinsEndo removed significantly more debris from the apical root canal irregularities when the needle tip was placed the most coronally. In contrast, McGill et al. (2008) found that the removal of

586

International Endodontic Journal, 43, 581–589, 2010

stained collagen from the root canal was more efficient when the RinsEndo needle tip was inserted 4 mm vs. 10 mm short of the working length. Previous studies performed with RinsEndo showed an enhanced penetration depth of a dye marked irrigant into root canal dentine (Hauser et al. 2007) and a superior efficacy in terms of tissue removal (Braun et al. 2005) than static syringe irrigation. In an investigation by McGill et al. (2008), removal of an ex vivo bio-molecular film model using RinsEndo and different techniques of manual irrigation was evaluated. It was demonstrated that irrigation with RinsEndo was significantly more effective than static manual irrigation but significantly less effective than agitation of the fluid with push-pull motions of a guttapercha point (manual-dynamic irrigation). The results of this study are in agreement with those results, demonstrating a significantly better cleaning efficacy with RinsEndo in comparison with static manual irrigation (subgroup A). However, PUI removed significantly more debris than RinsEndo with exception of size 30, 0.02 taper root canals where the difference between PUI and RinsEndo was not statistically significant. An explanation for the superior effectiveness of PUI may be the higher velocity of the irrigant and the acoustic streaming created during the use of ultrasound, leading to more effective delivery of irrigant to the root canal extensions. Also, irrigant flow rate is considered a highly significant factor determining flow pattern in fluid dynamics (Tilton 1999) and has been shown to influence the replacement of the irrigant in certain parts of the root canal (Nanzer et al. 1989). RinsEndo has a pre-set flow rate of 6.2 mL min)1, and the delivery rate for the ultrasonic irrigation was set at 10 mL min)1. Recently, it was demonstrated that PUI with a continuous flush of NaOCl for 3 min and a delivery rate of 15 mL min)1 was effective in removing debris from irregularities in the apical root canal third (van der Sluis et al. 2009). Although it is difficult to standardize and control the flow rate during syringe irrigation (Boutsioukis et al. 2007), the flow rate was set to approximately 6.6 mL min)1 in this study. The higher flow rate of the PUI may have contributed to a better removal of debris from simulated root canal irregularities. The flow rate for RinsEndo was slightly lower than for syringe irrigation but the pressuresuction technology and the automatically activation of the fluid resulted in a better removal of debris. From the studies where PUI and syringe irrigation were compared, it can be concluded that PUI is more effective in removing remnants of debris (Cheung & Stock 1993,

ª 2010 International Endodontic Journal

Ro¨dig et al. Removal of debris

Lee et al. 2004a, Passarinho-Neto et al. 2006), which is in concordance with the results of this study. In summary, this laboratory study demonstrated that none of the tested irrigation devices was able to completely remove debris from artificial irregularities in the apical part of the root canal. PUI removed significantly more debris than syringe irrigation irrespective of the diameter of the apical preparation. Except for an apical root canal preparation of size 30, 0.02 taper ultrasonic irrigation performed significantly better in debris removal than RinsEndo.

Conclusion Passive ultrasonic irrigation is more effective than syringe irrigation or RinsEndo in removing debris from artificial extensions in straight root canals whereas the size of the apical preparation does not play a decisive role.

Acknowledgement The authors are grateful to Du¨rr Dental for the loan of the RinsEndo device for research purposes.

References Abbott PV, Heijkoop PS, Cardaci SC, Hume WR, Heithersay GS (1991) An SEM study of the effects of different irrigation sequences and ultrasonics. International Endodontic Journal 24, 308–16. Abou-Rass M, Piccinino MV (1982) The effectiveness of four clinical irrigation methods on the removal of root canal debris. Oral Surgery Oral Medicine Oral Pathology 54, 323–8. Ahmad M, Pitt Ford TJ, Crum LA (1987a) Ultrasonic debridement of root canals: acoustic streaming and its possible role. Journal of Endodontics 13, 490–9. Ahmad M, Pitt Ford TR, Crum LA (1987b) Ultrasonic debridement of root canals: an insight into the mechanisms involved. Journal of Endodontics 13, 93–101. Ahmad M, Pitt Ford TR, Crum LA, Walton AJ (1988) Ultrasonic debridement of root canals: acoustic cavitation and its relevance. Journal of Endodontics 14, 486–93. Ahmad M, Roy RA, Kamarudin AG (1992) Observations of acoustic streaming fields around an oscillating ultrasonic file. Endodontics and Dental Traumatology 8, 189–94. Al Jadaa A, Paque´ F, Attin T, Zehnder M (2009) Necrotic pulp tissue dissolution by passive ultrasonic irrigation in simulated accessory canals: impact of canal location and angulation. Journal of Endodontics 42, 59–65. Baumgartner JC, Mader CL (1987) A scanning electron microscopic evaluation of four root canal irrigation regimens. Journal of Endodontics 13, 147–57.

ª 2010 International Endodontic Journal

Baumgartner JC, Brown CM, Mader CL, Peters DD, Shulman JD (1984) A scanning electron microscopic evaluation of root canal debridement using saline, sodium hypochlorite, and citric acid. Journal of Endodontics 10, 525–31. Boutsioukis C, Lambrianidis T, Kastrinakis E, Bekiaroglou P (2007) Measurement of pressure and flow rates during irrigation of a root canal ex vivo with three endodontic needles. International Endodontic Journal 40, 504–13. Braun A, Kappes D, Krause F, Jepsen S (2005) Efficiency of a novel rinsing device for the removal of pulp tissue in vitro. International Endodontic Journal 38, 923 (abstract). Brito PR, Souza LC, Machado de Oliveira JC et al. (2009) Comparison of the effectiveness of three irrigation techniques in reducing intracanal Enterococcus faecalis populations: an in vitro study. Journal of Endodontics 35, 1422– 7. Brunner E, Langer F (1999) Nichtparametrische Analyse longitudinaler Daten, 1st edn. Munich: Oldenbourg Verlag. Cheung GS, Stock CJ (1993) In vitro cleaning ability of root canal irrigants with and without endosonics. International Endodontic Journal 26, 334–43. Chow TW (1983) Mechanical effectiveness of root canal irrigation. Journal of Endodontics 9, 475–9. Cunningham WT, Martin H, Forrest WR (1982) Evaluation of root canal debridement by the endosonic ultrasonic synergistic system. Oral Surgery Oral Medicine Oral Pathology 53, 401–4. De Deus G, Reis C, Beznos D, de Abranches AM, CoutinhoFilho T, Paciornik S (2008) Limited ability of three commonly used thermoplasticized gutta-percha techniques in filling oval-shaped canals. Journal of Endodontics 34, 1401–5. Falk KW, Sedgley CM (2005) The influence of preparation size on the mechanical efficacy of root canal irrigation in vitro. Journal of Endodontics 31, 742–5. Goldman LB, Goldman M, Kronman JH, Lin PS (1981) The efficacy of several irrigating solutions for endodontics: a scanning electron microscopic study. Oral Surgery Oral Medicine Oral Pathology 52, 197–204. Grossman LI, Meiman BW (1941) Solution of pulp tissue by chemical agents. Journal of the American Dental Association 28, 223–5. Gu LS, Kim JR, Ling J, Choi KK, Pashley DH, Tay FR (2009) Review of contemporary irrigant agitation techniques and devices. Journal of Endodontics 35, 791–804. Gutarts R, Nusstein J, Reader A, Beck M (2005) In vivo debridement efficacy of ultrasonic irrigation following handrotary instrumentation in human mandibular molars. Journal of Endodontics 31, 166–70. Haapasalo M, Endal U, Zandi H, Coil J (2005) Eradication of endodontic infection by instrumentation and irrigation solutions. Endodontic Topics 10, 77–102. Haapasalo M, Qian W, Portenier I, Waltimo T (2007) Effects of dentin on the antimicrobial properties of endodontic medicaments. Journal of Endodontics 33, 917–25.

International Endodontic Journal, 43, 581–589, 2010

587

Removal of debris Ro¨dig et al.

Hauser V, Braun A, Frentzen M (2007) Penetration depth of a dye marker into dentine using a novel hydrodynamic system (RinsEndo). International Endodontic Journal 40, 644–52. Hsieh YD, Gau CH, Kung Wu SF, Shen EC, Hsu PW, Fu E (2007) Dynamic recording of irrigating fluid distribution in root canals using thermal image analysis. International Endodontic Journal 40, 11–7. Huang TY, Gulabivala K, Ng YL (2008) A bio-molecular film ex-vivo model to evaluate the influence of canal dimensions and irrigation variables on the efficacy of irrigation. International Endodontic Journal 41, 60–71. Huque J, Kota K, Yamaga M, Iwaku M, Hoshino E (1998) Bacterial eradication from root dentine by ultrasonic irrigation with sodium hypochlorite. International Endodontic Journal 31, 242–50. Khademi A, Yazdizadeh M, Feizianfard M (2006) Determination of the minimum instrumentation size for penetration of irrigants to the apical third of root canal systems. Journal of Endodontics 32, 417–20. Lee SJ, Wu MK, Wesselink PR (2004a) The effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal walls. International Endodontic Journal 37, 672–8. Lee SJ, Wu MK, Wesselink PR (2004b) The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from different-sized simulated plastic root canals. International Endodontic Journal 37, 607–12. Lumley PJ, Walmsley AD, Laird WR (1991) Streaming patterns produced around endosonic files. International Endodontic Journal 24, 290–7. Lumley PJ, Walmsley AD, Walton RE, Rippin JW (1993) Cleaning of oval canals using ultrasonic or sonic instrumentation. Journal of Endodontics 19, 453–7. McGill S, Gulabivala K, Mordan N, Ng YL (2008) The efficacy of dynamic irrigation using a commercially available system (RinsEndo) determined by removal of a collagen ‘biomolecular film’ from an ex vivo model. International Endodontic Journal 41, 602–8. Metzler RS, Montgomery S (1989) Effectiveness of ultrasonics and calcium hydroxide for the debridement of human mandibular molars. Journal of Endodontics 15, 373–8. Naenni N, Thoma K, Zehnder M (2004) Soft tissue dissolution capacity of currently used and potential endodontic irrigants. Journal of Endodontics 30, 785–7. Nair PN, Henry S, Cano V, Vera J (2005) Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after ‘‘one-visit’’ endodontic treatment. Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics 99, 231–52. Nanzer J, Langlois S, Coeuret F (1989) Electrochemical engineering approach to the irrigation of tooth canals under the influence of a vibrating file. Journal of Biomedical Engineering 11, 157–63.

588

International Endodontic Journal, 43, 581–589, 2010

Ørstavik D, Haapasalo M (1990) Disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules. Endodontics and Dental Traumatology 6, 142–9. Paque´ F, Laib A, Gautschi H, Zehnder M (2009) Hard-tissue debris accumulation analysis by high-resolution computed tomography scans. Journal of Endodontics 35, 1044–7. Passarinho-Neto JG, Marchesan MA, Ferreira RB, Silva RG, Silva-Sousa YT, Sousa-Neto MD (2006) In vitro evaluation of endodontic debris removal as obtained by rotary instrumentation coupled with ultrasonic irrigation. Australian Endodontic Journal 32, 123–8. Peters OA (2004) Current challenges and concepts in the preparation of root canal systems: a review. Journal of Endodontics 30, 559–67. Ram Z (1977) Effectiveness of root canal irrigation. Oral Surgery Oral Medicine Oral Pathology 44, 306–12. Roy RA, Ahmad M, Crum LA (1994) Physical mechanisms governing the hydrodynamic response of an oscillating ultrasonic file. International Endodontic Journal 27, 197–207. Sabins RA, Johnson JD, Hellstein JW (2003) A comparison of the cleaning efficacy of short-term sonic and ultrasonic passive irrigation after hand instrumentation in molar root canals. Journal of Endodontics 29, 674–8. Santos MD, Walker WA III, Carnes DL Jr (1999) Evaluation of apical seal in straight canals after obturation using the Lightspeed sectional method. Journal of Endodontics 25, 609–12. Scelza MF, Antoniazzi JH, Scelza P (2000) Efficacy of final irrigation–a scanning electron microscopic evaluation. Journal of Endodontics 26, 355–8. Sedgley CM, Nagel AC, Hall D, Applegate B (2005) Influence of irrigant needle depth in removing bioluminescent bacteria inoculated into instrumented root canals using real-time imaging in vitro. International Endodontic Journal 38, 97– 104. Spratt DA, Pratten J, Wilson M, Gulabivala K (2001) An in vitro evaluation of the antimicrobial efficacy of irrigants on biofilms of root canal isolates. International Endodontic Journal 34, 300–7. Stock CJ (1991) Current status of the use of ultrasound in endodontics. International Dental Journal 41, 175–82. Tilton JN (1999) Fluid and particle dynamics. In: Perry RH, Green DW, Maloney JO, eds. Perry’s Chemical Engineer’s Handbook, 7th edn. New York, USA: McGraw-Hill, pp. 1–50. van der Sluis LW, Wu MK, Wesselink PR (2005a) A comparison between a smooth wire and a K-file in removing artificially placed dentine debris from root canals in resin blocks during ultrasonic irrigation. International Endodontic Journal 38, 593–6. van der Sluis LW, Wu MK, Wesselink PR (2005b) The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper. International Endodontic Journal 38, 764–8. van der Sluis LW, Gambarini G, Wu MK, Wesselink PR (2006) The influence of volume, type of irrigant and flushing

ª 2010 International Endodontic Journal

Ro¨dig et al. Removal of debris

method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation. International Endodontic Journal 39, 472–6. van der Sluis LW, Versluis M, Wu MK, Wesselink PR (2007a) Passive ultrasonic irrigation of the root canal: a review of the literature. International Endodontic Journal 40, 415–26. van der Sluis LW, Wu MK, Wesselink PR (2007b) The evaluation of removal of calcium hydroxide paste from an artificial standardized groove in the apical root canal using different irrigation methodologies. International Endodontic Journal 40, 52–7. van der Sluis LW, Wu MK, Wesselink P (2009) Comparison of 2 flushing methods used during passive ultrasonic irrigation of the root canal. Quintessence International 40, 875–9. Walters MJ, Baumgartner JC, Marshall JG (2002) Efficacy of irrigation with rotary instrumentation. Journal of Endodontics 28, 837–9.

ª 2010 International Endodontic Journal

Weller RN, Brady JM, Bernier WE (1980) Efficacy of ultrasonic cleaning. Journal of Endodontics 6, 740–3. Wu MK, Wesselink PR (1995) Efficacy of three techniques in cleaning the apical portion of curved root canals. Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics 79, 492–6. Wu MK, Wesselink PR (2001) A primary observation on the preparation and obturation of oval canals. International Endodontic Journal 34, 137–41. Zehnder M (2006) Root canal irrigants. Journal of Endodontics 32, 389–98. Zmener O, Pameijer CH, Serrano SA, Palo RM, Iglesias EF (2009) Efficacy of the NaviTip FX irrigation needle in removing post instrumentation canal smear layer and debris in curved root canals. Journal of Endodontics 35, 1270–3.

International Endodontic Journal, 43, 581–589, 2010

589