|Year : 2016 | Volume
| Issue : 4 | Page : 171-178
Efficacy of EndoVac system and needle irrigation on root canal debridement
Saleh A Abdelglil Bsc 1, Ali M Farag2, Hatem A El-Hediny2, Abeer M Darrag2
1 Department of Endodontic, Ministry of Health, Tanta, Egypt
2 Department of Endodontic, Faculty of Dentistry, Tanta University, Tanta, Egypt
|Date of Submission||09-Apr-2016|
|Date of Acceptance||27-Oct-2016|
|Date of Web Publication||14-Dec-2016|
Saleh A Abdelglil
Ministry of Health, Elashraf Street, Gharbia, Tanta
Source of Support: None, Conflict of Interest: None
The aim of this study is to compare the debridement efficacy of the EndoVac irrigation system versus needle irrigation with different irrigant solutions using scanning electron microscope.
Materials and methods
Eighty human freshly extracted single rooted teeth with fully developed, single root canals were collected. The teeth were divided randomly into two equal main groups according to the method of irrigation system used: group A, EndoVac system; and group B, needle irrigation. Each group was further subdivided into four equal subgroups according to the type of irrigant solution used: subgroup 1; sodium hypochlorite (NaOCl), subgroup 2; EDTA, subgroup 3; mixture of tetracycline, acid and detergent (MTAD), subgroup 4; saline. The canals were instrumented to a master apical file size #40/0.02 taper. Roots were split longitudinally in a buccolingual direction and examined under scanning electron microscope.
At all tested root canal levels, group A recorded lower mean rank of score percentage compared to group B with statistical significant difference between them (P = 0.001 and 0.039 at the middle and the apical root level, respectively), while there was no statistical significant difference between both groups (P = 0.053) at the coronal root level.
The debridement efficacy of NaOCl only, NaOCl+EDTA, NaOCl+MTAD or even saline increased when using EndoVac system rather than conventional needles especially in the apical third.
Keywords: conventional needle, debris, EndoVac, root canal irrigation, smear layer
|How to cite this article:|
Abdelglil SA, Farag AM, El-Hediny HA, Darrag AM. Efficacy of EndoVac system and needle irrigation on root canal debridement. Tanta Dent J 2016;13:171-8
|How to cite this URL:|
Abdelglil SA, Farag AM, El-Hediny HA, Darrag AM. Efficacy of EndoVac system and needle irrigation on root canal debridement. Tanta Dent J [serial online] 2016 [cited 2017 Jun 22];13:171-8. Available from: http://www.tmj.eg.net/text.asp?2016/13/4/171/195705
| Introduction|| |
Root canal therapy is directed to prevent periradicular periodontitis  which trigger an inflammatory vascular response in the periodontium . This response is caused by pathogenic microorganisms such as bacteria, fungi, and viruses. There are also nonliving materials such as dentin and cementum chips as well as foreign debris that permeated through the apex, lateral accessory canals or dentinal tubules and directly or indirectly illicit an inflammatory response .
In order to eradicate microorganisms from the root canal system, irrigation solutions are recommended as an adjunct to mechanical preparation of the root canal system in a process called chemomechanical debridement . Even with enlargement of the canal space, mechanical debridement cannot completely sterilize the canal. So canal instrumentation must be supplemented with using of irrigation solutions to enhance canal debridement and smear layer removal .
Sodium hypochlorite (NaOCl) is the most commonly used irrigation solution in endodontics because of its antimicrobial activity, dissolving vital and necrotic tissues, lubricating action, low cost, and availability . Additionally, EDTA is a common chelating agent used in the irrigation of root canals during endodontic therapy due to its ability to remove smear layer [7,8]. It complements the action of NaOCl where alteration of NaOCl irrigation with 17% EDTA could facilitate removal of the smear layer and bacterial biofilm from noninstrumented surfaces . Moreover, mixture of tetracycline, acid and detergent (MTAD) is a new generation of irrigant solutions introduced in 2003 by Torabinejad et al.  It is based on the synergic action of an antibiotic (antibacterial activity), citric acid (removing the smear layer), and a detergent that should permit a deeper penetration of the solution into dentinal tubules. It shows a very high capability in removing the smear layer and antibacterial activity .
Several authors have suggested that the root canal acts like a 'closed-end channel,' with the apex being the closed-end. Therefore, gas becomes trapped at the apical extent of the canal during irrigation delivery creating a 'vapor lock effect,' which occurs clinically in the apical aspect of the closed system of the root canal and the irrigation efficacy will be negatively affected . So irrigation with negative pressure has been used to safely enhance debridement and disinfection of the apical aspect of the root canal system .
EndoVac is a negative pressure irrigation system that was invented by John Schoeffel. The system generates negative pressure that draws irrigation solution apically via suction from the high volume evacuation of the dental unit. This system is composed of a master delivery tip (MDT), macrocannula and microcannula. The MDT delivers copious amounts of irrigation solution to the access opening while at the same time evacuating debris and excess solution. The macrocannula removes debris remaining in the canal from instrumentation as well as delivering irrigation solution from the MDT. The microcannula evacuates microscopic debris and irrigation solution from the apical extent of the root canal, down to the level of the working length (WL) via its microscopic, laser-drilled holes .
Additionally, the presence of the smear layer may interfere with the adhesion of root canal sealers to the canal walls, thus compromising the quality of obturation. It may also slowly disintegrate and dissolve around a root canal filling material leaving voids between the canal wall and sealer , it was concluded that smear layer removal improved the fluid tight seal of the root canal system .
To our knowledge, researches on the debridement efficacy of EndoVac are limited using NaOCl, EDTA and MTAD, therefore the cleaning efficacy of the this irrigation system versus needle irrigation with different irrigant solutions was evaluated in this study using scanning electron microscope (SEM) at different levels of root canals.
| Materials and methods|| |
Eighty human freshly extracted single rooted teeth with straight, mature fully developed, single root canals with anatomically similar dimensions were collected from the out-patient clinic of Oral Surgery Department, Faculty of Dentistry, Tanta University. Only those teeth with a fully formed apex were selected, whereas roots with resorption defects, fractures or open apices were excluded. All patients were informed and signed a written consent about the purpose of the study and using their extracted teeth in this research according to ethics committee of Faculty of Dentistry, Tanta University.
Root canal instrumentation
Access opening was performed and WL was determined. The teeth were divided randomly into two equal main groups according to the method of irrigation system used: group A for EndoVac (Discus Dental, Culver City, California, USA), and group B for needle irrigation. Each group was further subdivided into four equal subgroups according to the type of irrigant solution used.
All root canals were instrumented using step back technique with hand stainless steel K-files (Dentsply Maillefer, Ballaigues, Switzerland) taper 0.02 up to master apical file #40.
Subgroup A1: EndoVac with sodium hypochlorite
The irrigant was delivered according to the manufacturer's instructions. During file instrumentation, 1 ml of 5.25% NaOCl (Clorox Co., 10 th of Ramadan, Egypt) was replenished after each file. When the master apical files reach the WL, the canal was macroirrigated and microirrigated following the manufacture instruction. 5.25% NaOCl using a macrocannula was inserted into the canal and moved up and down for 30 s. The NaOCl was sucked through the tip of the macrocannula while the NaOCl was replenished via the syringe tip. The irrigant was left undisturbed for 60 s. After macroirrigation, three cycles of microirrigation were accomplished using a microcannula which was placed 2 mm short of WL for 6 s, then at WL for 6 s, and finally alternating between these positions for a total of 30 s. The microcannula was removed, and the irrigant was left undisturbed for 60 s. This completed one cycle of microirrigation and this was repeated for three cycles .
Subgroup A2: EndoVac with sodium hypochlorite and EDTA (Pulpdent, Watertown, Massachusetts, USA)
Root canals were irrigated as in subgroup A1 in the first cycle, but EDTA was used in the second cycle and NaOCl in the third cycle.
Subgroup A3: EndoVac with sodium hypochlorite and mixture of tetracycline, acid and detergent (Dentsply Tulsa Dental Specialties, Tulsa, Oklahoma, USA)
Root canals were irrigated as in subgroup A1 in the first cycle, but MTAD was used in the second and third cycles.
Subgroup A4: EndoVac with saline
Root canals were irrigated as in subgroup A1 using normal saline solution only in all cycles of microirrigation as a control group.
After the final cycle of microirrigation, the microcannula was left at WL without replenishment to suction the remaining fluid.
Subgroup B1: needle irrigation with sodium hypochlorite
The pulp chamber and canal was irrigated using a plastic syringe with a 30-G closed-end needle (NaviTip; Ultradent, USA). 1 ml of 5.25% NaOCl was used after each instrument. During the irrigation, the needle was moved up and down during irrigation. Once the master apical file reached the WL. The canal received irrigation 5.25% NaOCl for 30 s. The irrigant was left undisturbed for 60 s and three additional cycles of irrigation were followed. Each cycle involved irrigation with the needle moving from 2 mm from WL to 4 mm from WL in constant motion for 30 s, followed by 60 s where the irrigant was left undisturbed. NaOCl was used in the three cycles .
Subgroup B2: needle irrigation with sodium hypochlorite and EDTA
Root canals were irrigated as subgroup B1 in the first cycle, but EDTA was used in the second cycle, then NaOCl in the third cycle.
Subgroup B3: needle irrigation with sodium hypochlorite and mixture of tetracycline, acid and detergent
Root canals were irrigated as subgroup B1 in the first cycle, but MTAD was used in the second and third cycles.
Subgroup B4: needle irrigation with saline
Root canals were irrigated as in subgroup B1, but normal saline solution only was used in the three cycles as a control group.
After complete cleaning and shaping, all root canals for the two groups were finally flushed with 5 ml normal saline solution and dried with paper points (Diadent Group International, Burnaby, Canada).
Scanning electron microscopic evaluation
Roots were split longitudinally in a buccolingual direction and then mounted on metallic stubs, sputter gold-coating and then were examined under SEM (JSM-5300 Scanning Microscope; JEOL, Peabody, Massachusetts, USA) with different magnification (×350-×1000). Root canal cleanliness was evaluated at the coronal, middle, and apical root canal thirds according to a scoring system recorded by Silva et al.  score 0: surface free of debris and totally exposed dentinal tubules, score 1: root surface partially covered with debris and score 2: root surface totally covered with debris with no visible dentinal tubules openings.
The score percentage of root canal cleanliness for different groups and subgroups at each root canal levels was collected, tabulated and statistically analyzed using SPSS statistic package (version 17; SPSS Inc., Chicago, Illinois, USA). Kruskal-Wallis test was used to reveal statistically significant differences among tested groups or subgroups. Whenever statistically significant difference was recorded, Mann-Whitney pairwise comparison test was performed to compare between each two tested subgroups with significance level of P less than and equal to 0.05.
| Result|| |
Regarding root canals irrigated with EndoVac system [Table 1]. The results revealed that 90% of the three experimental subgroups recorded score 0 at the coronal root level as shown obviously in [Figure 1] while 80% of samples of subgroup A4 recorded score 1 at the middle root level as shown in [Figure 2].
On the other hand, the result of root canals irrigated with needle irrigation system [Table 2] revealed that 80% of samples of subgroup B1 recorded score 1 at the middle root level as shown in [Figure 3], while at the coronal root level, 70% of subgroup B2 recorded score 0 shown in [Figure 4], on the other hand at the apical root level, 60% of subgroup B3 recorded score 1 and 100% of subgroup B4 recorded score 2 as shown in [Figure 5] and [Figure 6], respectively.
It was necessary to compare the cleaning efficacy at the three root levels regardless of the system used in irrigation and the irrigant solutions [Table 3].
The highest mean rank of score percentages was recorded at the apical root canal level descending till reaching the coronal root level with a statistical significant differences among the three tested root canal levels (P < 0.05).
|Figure 1: Scanning electron microscope photomicrographs of the coronal level of root canal wall irrigated with EndoVac irrigation system after sodium hypochlorite irrigation solution. Surface free of debris, complete removal of the smear layer, all dentinal tubules are clean and open (score 0). Original magnifications, ×1000|
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|Figure 2: Scanning electron microscope photomicrographs of the middle level of root canal wall irrigated with EndoVac irrigation system after Saline irrigation solution showing score 1 where the surface partially covered with debris with some open tubules. Original magnifications, ×1000|
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|Figure 3: Scanning electron microscope photomicrographs of the middle level of root canal wall irrigated with needle irrigation system after sodium hypochlorite irrigation solution showing score 1 where the surface partially covered with debris with some open tubules. Original magnifications, ×1000|
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|Figure 4: Scanning electron microscope photomicrographs of the coronal level of root canal wall irrigated with needle irrigation system after 17% EDTA irrigation solution. Surface free of debris, complete removal of the smear layer, all dentinal tubules are clean and open (score 0). Original magnifications, ×350|
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|Figure 5: Scanning electron microscope photomicrographs of the apical level of root canal wall irrigated with needle irrigation system after mixture of tetracycline, acid and detergent irrigation solution showing score 1 where the surface partially covered with debris with some open tubules. Original magnifications, ×1000|
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|Figure 6: Scanning electron microscope photomicrograph of apical level of root canal wall irrigated with needle irrigation system after saline final irrigation totally covered with dentin debris and thick, nonhomogenous smear layer with no open dentinal tubules at the coronal level (score 2). Original magnification, ×1000|
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|Table 1 Score percentages of different irrigating solutions (subgroups) at the three root canal levels using EndoVac irrigation systems (group A) |
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|Table 2 Score percentages of different irrigating solutions at the three root canal levels using needle irrigation systems (group B) |
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|Table 3 Score percentages of the three root canal levels regardless of the system used in irrigation (groups) and regardless of the irrigant solutions (subgroups) |
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| Discussion|| |
Adequate instrumentation combined with effective irrigation is required to achieve sufficient disinfection during root canal treatment [18,19]. Irrigants have traditionally been delivered into the root canal space using syringes and metal needles of different sizes and tip designs despite they are difficult to control for pressure, and accidents may happen. Previous studies shown that needle irrigation methods do not effectively debride the entire root canal apically, they are effective only at cleaning the root canal coronally, EndoVac is a novel irrigation system based on the negative apical pressure whereby the irrigant placed in the pulp chamber is sucked down the root canal and back up again through a thin needle with special design [20,21]. Therefore, this study was performed to determine the effectiveness of root canal debridement using EndoVac and conventional needle in association with different irrigation solutions.
Natural teeth were used in the present study although they show large variations in dentin hardness and root canal morphology, but their use seems to be the only way to evaluate the cleaning ability of a preparation technique. In addition, preparation of artificial canals in plastic blocks does not reflect the behavior of the instruments in a natural canal or natural dentin removal behavior .
Root canal preparation was performed up to master apical file #40 to allow the microcannula with closed-end measuring ISO #32 to reach the apex while ending step back with file #60 to allow the macrocannula with open end measuring ISO #55 to be used in the coronal two-third.
NaOCl appears to be the best available canal irrigant owing to its antibacterial and organic tissue dissolving properties , so it was used in this study to compare the cleaning efficiency under simple irrigation regimen.
It is recommended to use antibacterial irrigants in combination with chelating agents, such as EDTA, in order to remove debris as well as the inorganic/organic smear layer , 1 ml of 17% EDTA with a contact time of 1 min was used in this study because Calt and Serper  found that EDTA when applied for more than 1 min caused excessive dentinal erosive effects. In addition, 1 ml of EDTA was effective as 10 ml in smear layer removal .
Furthermore, MTAD was used in this study which is recommended as a final rinse after initial irrigation with NaOCl . MTAD has been shown to be a clinically effective in removing the smear layer, biocompatible  with sustained antibacterial activity .
SEM is a reliable tool for showing a detailed view  and proved to be an efficient method to investigate the influence of different endodontic instruments on the cleanliness of dentin surfaces. So that two magnifications (×350 and × 1000) were used in this study. At low magnification (×350) large amounts of debris could be easily seen, but details such as remnants of the smear layer could be seen at high magnification (×1000).
The findings of the present study revealed that even with the use of EndoVac, complete removal of smear layer was not possible in the apical third of the root canal. This could possibly be due to the nature of dentinal tubules which are irregular and less in number. However, EndoVac has proved to be more effective for debridement of root canal . This method allows the delivery of the irrigant to the WL causing the irrigant to reflux and displacing the debris coronally without expression of the irrigant into periapical tissues . This was supported by several authors who found that EndoVac has been shown to be a controlled effective method to deliver irrigant to the apical third of the canal system . Heilborn et al.  has shown EndoVac to achieve better root canal cleaning at the apical third with less exposure time than that required with traditional needle irrigation.
The results obtained in this study were in agreement with other researches [34,35] who reported that EndoVac system proved superior in debridement and disinfection of the root canal system as compared to conventional needle irrigation.
Comparing between the three root levels regardless of the irrigation systems and irrigation solutions, the results indicated that better cleaning was found on the coronal third followed by the middle third and finally the apical third. The cleaning difficulty on the apical third may be explained by the reduction in root canal diameter which impairs the access of the irrigants, reduction in its flow and difficulty of its removal .
NaOCl solutions remain the most widely recommended irrigant in endodontics on the basis of its unique capacity to dissolve necrotic tissue remnants and excellent antimicrobial potency . However, in this study, specimens irrigated with 5.25% NaOCl showed presence of an irregular smear layer at the apical third under SEM. These findings were consistent with the findings of the previous studies  who reported that NaOCl 5.25% at 37°C did not completely remove the smear layer from the apical third of the canals.
Under SEM, the current result demonstrated that the specimens irrigated with 5.25% NaOCl followed by 17% EDTA solution showed dentin surface in the coronal and middle thirds of root canals free of smear layer and debris. This was consistent with several authors  who observed that alternating the use of EDTA and NaOCl is effective method for smear layer removal. These findings may be attributed to that EDTA facilitates decalcification of the inorganic component and NaOCl promotes dissolution of the organic matrix .
When the specimens surface at the apical third irrigated with EDTA were viewed, root surface was found to be clean with smear layer present in the tubules. Decline in the smear layer removal efficacy of EDTA along the apical third of the root canals might be attributable to inadequate volume and or penetration of the solution in narrow portion of the canal during instrumentation. These findings are in agreement with the findings of Torabinejad et al. .
The results obtained in this study for this irrigation were similar to those gathered by several authors [39,40].
The present data revealed that MTAD did not completely remove the smear layer from the apical third of the canals but it is effective at the coronal and middle thirds. This finding is in agreement with that of Mancini et al.  while it is in contrast with the results of Torabinejad et al. [10,28] showing an effective cleaning action with MTAD in the apical third. These discrepant findings can be explained by our use of 1 ml of the final irrigants for 1 min, whereas Torabinejad and colleagues followed the manufacturer's instruction using a total of 5 ml of the testing solution (1 ml per 5 min and then a flush with 4 ml). Modification of the time and volume to standardize the study procedure for the solutions tested.
An initial rinse of prepared root canals with NaOCl was recommended to enhance the efficacy of MTAD to dissolve the smear layer . Tay et al.  reported that the effect of this combined use was equal to that of EDTA. In the present study, this combination had similar effectiveness to that of EDTA, especially in the apical third which is in agreement with Ureyen et al.  on the other hand this finding disagree with the results of other researchers [40,44] who proved that the best results and outstanding efficacy were associated with MTAD solution compared to EDTA. In addition, some authors demonstrated that the removal of the smear layer was most efficient when 1 ml of MTAD solution was applied for 5 min after NaOCl as a basic irrigation .
| Conclusion|| |
Within the limitations of the present in-vitro study, the results suggest that the debridement efficacy of NaOCl only, NaOCl+EDTA, NaOCl+MTAD or even saline increased when using EndoVac rather than conventional needles especially in the apical third. Regardless of root canal level, the highest debridement efficacy was recorded when using NaOCl-EDTA and NaOCl-MTAD followed by NaOCl only.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1], [Table 2], [Table 3]