Emergency treatment in teeth with symptomatic apical
periodontitis
a randomized clinical study
Running title: Emergency treatment in teeth with symptomatic
apical periodontitis
Märta Stenberg
Handledare: Eva Wolf
Examensarbete (30hp)
Malmö högskola
Tandläkarprogrammet
Odontologiska fakulteten
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Abstract
The aim was to compare the pain relieving effect of complete chemo mechanical disinfection of the root canal system with removal of necrotic tissue in the pulp chamber without instrumentation of the root canals as emergency treatment in teeth with symptomatic apical periodontitis.
The material consisted of 16 patients collected at the emergency clinic at Malmö University. Patients with swelling and/or systemic involvement were excluded.
The patients were randomized to either treatment. The preoperative pain level and intake of analgesics was registered. Three till 5 days postoperatively the patients were contacted and asked to grade the current pain level and intake of analgesics and/or antibiotics.
The results showed that 100% of the patients treated with complete chemo mechanical disinfection of the root canal system obtained satisfying pain relief compared to 71% for patients treated with removal of necrotic tissue in the pulp chamber.
44% of the patients treated with chemo mechanical disinfection of the root canal system had some kind of analgesics post-operatively compared to 29% for those treated with removal of necrotic tissue in the pulp chamber. No patients in either group reported use of antibiotics postoperatively.
The conclusion was that both complete chemo mechanical disinfection and removal of necrotic tissue implied a significant pain relief as emergency treatment in teeth with symptomatic apical periodontitis. There was no difference between the two treatments concerning the number of patients who obtained sufficient pain relief or in pain relieving effect.
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Keywords: symptomatic apical periodontitis, endodontic emergency treatment, infection, necrotic, Numeric Rating Scale, pain relief
Sammanfattning
Syftet med denna masterstudie var att jämföra den smärtlindrande effekten av fullständig utrensning och desinfektion av rotkanalsystemet med enbart utrymning av pulpakavum, utan instrumentering av rotkanalerna, som akutbehandling hos tänder med symtomatisk apikal parodontit.
Materialet utgjordes av 16 patienter insamlade på Tandvårdshögskolans jourmottagning. Patienter med svullnad och allmänpåverkan exkluderades.
Patienterna valdes slumpmässigt ut till att genomgå någon av behandlingarna. Den preoperativa smärtnivån och ev. analgetikaintag registrerades. Tre till fem dagar efter utförd behandling kontaktades patienterna per telefon och fick då gradera sin postoperativa smärtnivå samt analgetika- och/eller antibiotikaintag.
Resultatet visade att 100% av patienterna som behandlades med fullständig utrensning erhöll tillfredställande smärtlindring jämfört med 71% av de patienter som behandlades med enbart utrymning av pulpakavum. Skillnaden var inte statistiskt signifikant.
44% av patienterna som behandlades med fullständig utrensning hade tagit smärtstillande postoperativt medan 29% av patienterna i utrymningsgruppen hade gjort det. Skillnaden var inte signifikant. Ingen av patienterna oavsett behandling hade tagit antibiotika efter behandlingen.
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Ingen skillnad förelåg i andelen patienter som blev tillräckligt smärtlindrade mellan fullständig utrensning och enbart utrymning av pulpakavum hos tänder med symtomatisk apikal parodontit. Det var inte heller någon skillnad i smärtsänkning mellan de två behandlingarna.
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Background
The vital condition of the pulp is at risk as a result of micro-organisms and their toxins. They can reach the pulp, most commonly through dental caries, but also by fractures of the dental hard tissues and/or leaking restorations. The early response of the pulp is an inflammation that eventually will lead to necrosis of the pulp (1). A necrotic pulp offers a favorable environment for bacteria and allows them to aggregate and form resistant biofilms (2). Although the oral microflora consists of more than 300 bacterial species, only few of them are able to infect the necrotic pulp and survive (3).
Apical periodontitis is the inflammatory response in the periapical tissues against a bacterial infection situated in the root canals of a tooth and may also induce a destruction of the surrounding bone. A study performed on monkeys showed that bone lesion could only develop when an infection was present in the necrotic tooth and not when the tooth was necrotic but non infected (4).
Acute pain from a vital or necrotic tooth is a frequent occurrence in the endodontic practice (5). Often the available time to perform the treatment is limited due to an already fully booked calendar and so the purpose of the emergency treatment in these patients is to reduce the pain to an acceptable level as efficient as possible.
A number of studies have been made to find the best and most cost effective emergency treatment options for acute symptoms rising from vital and necrotic teeth. This includes removal of the inflamed or necrotic tissue in the pulp chamber, complete chemo mechanical disinfection of the root canal system and systemic antibiotic treatment alone or in combination with other treatments (6-8). A range of studies have shown good result for pulpotomy as emergency treatment in symptomatic vital teeth with approximately 90% of the treated
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patients obtaining pain relief post-operatively. The pain relief was measured as completely free of symptoms, mild post-operative pain or low return frequency for additional treatment in the different studies made on this topic (9-13). This result is comparable with those of complete chemo mechanical disinfection of the root canal system in vital teeth, but pulpotomy can be seen as a more cost effective option at the acute situation because of a shorter treatment time needed (11, 13-14).
Systemic antibiotic as symptomatic treatment in vital teeth is considered non-adequate. This is due to that the infection is located in the hard tissues of the tooth (dental caries) and so antibiotics can't reach it to with the blood stream to eliminate it (15). However, systemic antibiotic treatment alone has been found to have a pain relieving effect in patients with a symptomatic necrotic tooth (6), while antibiotics as additional treatment to complete chemo mechanical disinfection of the root canal system was found to have no additional effect on pain relief (7-8).
Considering removal of necrotic tissue in the pulp chamber, Molander et al. (2004)(12), showed in a prospective study with 76 patients that the pain relief in necrotic teeth was considered sufficient in approximately 75% of the patients. In a retrospective study with 2184 patients, Bjerkén et al. (1980)(13) found a return frequency of 25% within 10 days in patients treated with only removal of necrotic tissue in the pulp chamber, compared to a 9% return frequency among patients receiving a complete disinfection of the root canal system at the emergency treatment occasion.
Other studies showed that 73-89% of patients treated with complete chemo mechanical disinfection obtained pain relief operatively. Many of them required though a post-operative intake of peripheral analgesics (7-8, 16).
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Very few studies can be found which investigate emergency treatment in necrotic teeth and no randomized controlled clinical study could be found in which the pain relieving effect of a complete chemo mechanical disinfection of the root canal system is compared to the removal of necrotic tissue in the pulp chamber but without instrumentation of the root canals.
The aim of this prospective, randomized clinical study was to compare complete chemo mechanical disinfection of the root canal system with removal of necrotic tissue in the pulp chamber but without instrumentation of the root canals as emergency treatment in teeth with symptomatic apical periodontitis, with the outcome measure pain relief. The expected result and hypothesis was to find that the root canal infection as the etiological factor of the experienced pain must be completely eliminated by complete chemo mechanical disinfection in order to achieve a satisfying pain relief in a majority of patients.
Material and methods
Subjects
The study included consecutive adult patients attending the emergency clinic at the Faculty of Odontology, Malmö University, Malmö, Sweden during March-October 2012, where they were clinically diagnosed with a symptomatic apical periodontitis.
The patients reported spontaneous pain and/or pain on percussion and palpation of the area. The patients graded their pain from 0-10 on the Numeric Rating Scale (NRS), and those who graded their pain with NRS >3 were included in the study. Included patients were also required to have the possibility to return to the clinic within two weeks and accepted to be contacted by phone within 3-5 days after the emergency treatment.
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Those patients where the current tooth had received previous endodontic treatment and those where additional treatment with antibiotics or incision would be needed were excluded. Indications for antibiotics and/or incision were intra- and/or extra oral swelling and fever as an indicator of systemic involvement.
Treatment
The examinations and the following treatments were executed by general or specialized dentists or by supervised undergraduate students at the emergency clinic.
The patients were randomized using a randomization chart made in Microsoft Office Excel 2007 with numbers from 1-1000, to be treated either by removal of necrotic tissue in the pulp chamber (odd numbers) but without instrumentation of the root canals (RNT) or by complete chemo mechanical disinfection (even numbers) of the root canal system (CMD).
Excavation of present caries was made in all the symptomatic teeth when necessary and an access preparation was made with the purpose to expose all root canal entrances.
The RNT treatment was performed without the use of rubber dam and the pulp chamber was cleaned from necrotic and infected tissue with the rinse of non sterile water. The patients were scheduled for a new appointment within two weeks after the treatment for complete chemo mechanical disinfection of the tooth.
The CMD treatment was performed with the use of rubber dam. The working area had to be well isolated without leakage from the oral cavity. The tooth and the rubber dam clamp were disinfected with a 30% solution of hydrogen peroxide (APL, ApotekProduktion&Laboratorier AB) while the entire field of operation including tooth, clamp and rubberdam was disinfected with a 0,5% chlorhexidine-alcohol (Fresenius Kabi). The root canals were cleaned and shaped using the crown-down concept with K3 rotary instrumentation (Dentsply, DeTrey GmbH,
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Konstanz, Germany) and/or manual instruments following the ISO-standardization, till adequate size where necrotic tissue as well as infected dentin was removed, depending on the size of the root canal. The chemical rinse consisted of an irrigation with 0,5% buffered NaOCl solution(Dakin’s solution) and a 15% ethylenediaminetetraacetic acid (EDTA) solution (APL, ApotekProduktion&Laboratorier AB). Calcium hydroxide was the temporary dressing in the root canals. After the treatment, all the teeth were sealed with a temporary filling of zinc oxide-eugenol cement (ZOE) and a glass ionomer cement( Ketac™ Fil, 3M ESPE Dental Products, Germany).
All patients were contacted by phone 3-5 days after the emergency treatment and were reminded of their pre-operative grading on NRS and were then asked to grade their current post-operative pain according to NRS. Patients with NRS ≤ 3 post-operatively were considered satisfying pain relieved. Their possible post-operative use of analgesics and antibiotics was registered.
Power analysis
A statistical power analysis was conducted using parts of the data from one study (Bjerkén et al. 1980) (13) that had evaluated both complete chemo mechanical disinfection and removal of necrotic tissue in the pulp chamber. With two groups, each consisting of 95 test subjects, the chances of obtaining a statistically significant result is 80%, if there is a difference of 16,5% (90,5% vs 74%) between the groups.
Statistics
For the calculations the Predictive Analytic SoftWare (PASW) Statistics 18 was used. The statistical method of 2x2 tables was the Chi square test or Fisher's exact test when the proportions were small and the expected value < 5. The calculations were two-tailed. Results were considered statistical significant at p < 0.05.
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Ethical considerations
An ethical consideration concerning leaving necrotic and infected tissue in a tooth was made. By informing the patients about possible consequences, giving them a new appointment for removal of the necrotic tissue, this was considered enough to keep the patient's state under control. Patients were also welcome to contact the clinic for additional treatment if needed before scheduled appointment.
The study was approved by the Local Ethical Review Board at the Faculty of Odontology, Malmö University, Malmö Sweden according to the World Medical Association (WMA) Declaration of Helsinki - Ethical Principles for Medical Research Involving Human Subjects (17). The patients also signed an informed consent before they participated in the study.
Results
There were 19 patients included in the study. Three patients were drop-outs, two women and one man between 46 and 75 years old with the average age of 59.3 years old. The cause was non-accessible and/or narrow root canals and so the pre-determined treatment was not possible to execute at the first treatment occasion.
There were nine patients treated in the CMD group and seven patients in the RNT group. Five of the patients were men, 11 were women. The patients were between 23 and 88 years of age. The average age of the treated patients was 48.5 years.
Dental students performed the treatment in four patients in the CMD group and in four patients in the RNT group while dentists performed the treatment in five patients in the CMD group and in three patients in the RNT group.
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In the CMD group all nine patients obtained satisfying pain relief three to five days postoperatively (NRS ≤ 3) while the number for those in the RNT group was five of the seven treated patients (p = 0.18).
Within three to five days postoperatively, four of the patients in the CMD group had an intake of peripheral analgesics. The number in the RNT group was two patients (p= 0.63). No patient irrespective of treatment had an intake of antibiotics within 3-5 days post-operatively. The pain ratings pre- and postoperatively are visualized in Figure 1 and Figure 2. The average pain rating for the patients in the CMD group preoperatively was NRS 6.44 and had postoperatively decreased to NRS 1.33 (p <0.005). In the RNT group the average pain preoperatively was NRS 7.14 and postoperatively it had decreased to NRS 2.29 (p = 0.005).The patients in the CMD group lowered their pain with 79% on NRS in total, while number in the RNT group was 68%. There was no difference in pain relief between the groups (p = 0.85).
Discussion
Both CMD and RNT implied a significant pain relieving effect as emergency treatment for teeth with symptomatic apical periodontitis (p ≤ 0.005). However, there was no difference between the two treatments concerning the number of patients who obtained satisfying pain relief (p= 0.18) or in pain relieving effect (p = 0.85).
The collection of material for this master project lasted for a limited time and only on certain days every week. Due to this, the number of patients collected was not satisfying and the power is insufficient. As a consequence, the results must be interpreted with caution. Statistical calculations showed however that the double amount of patients was needed to get
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a significant difference between the two groups concerning satisfying pain relief postoperatively, provided that the same difference between the groups would persist.
Another factor that had an impact on the collected material was a large number of dentists and students operating at the emergency clinic and some of these were not informed about the study and therefore some patients was not asked to participate despite suitable criteria. The large number of operators may also have affected the possibilities to compare the performed treatments although clear instructions were given considering the treatment process. It is also likely that the dentists performing some of the treatments have been more skilled than the students performing the treatment and so it could also have affected the obtained results. However, the most important aspect of the treatment was to obtain complete removal of the necrotic tissue in the canals when the patients were treated with CMD and this was done in all the included cases since they were all cleaned with adequate sizes of the instruments, depending on the size of the canal. The large number of treating dentists and students with different experience reflects the clinical reality and so it has not been a disadvantage when showing a result that is applicable in the daily clinical situation.
Patients with more severe cases of apical periodontitis that would have required antibiotics in addition to the endodontic treatment were excluded from the study since the RNT treatment would have posed a greater risk of further development of metastatic infections since the source of infection would not have been completely removed. Because of the big amount of treating dentists and students who were not directly involved in the study, the number of patients who were excluded from participation was not registered. This did not have any importance for the results found in the study but would have been valuable for measuring the prevalence of symptomatic apical periodontitis. For the same reason, patients who did not have a pre-operative value of NRS ≤ 3 or patients where the chosen treatment was extraction were not registered.
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For measuring pain we chose to use NRS instead of the Visual Analogue Scale (VAS) (18) that was used in the reference article (12). VAS is a visual scale that requires an active participation from the patient and it was therefore not suitable for our study where the patients were asked to grade their postoperative pain over the phone. NRS has in addition been found to have a slightly better validity in detecting differences in different painful stimulus intensity compared to the VAS (19). Values lower than 4 on NRS correspond to no pain or mild pain and to be able to measure the level of pain relief, patients with a value lower than 4 on NRS were not included (20). We also chose to remind the patients of their preoperative grading since patients tend to overrate their post-operative pain when they do not have access to their previous grading (21). Pain is however a subjective experience and sufficient pain relief may not have the same meaning to each individual when measuring pain on a pain rating scale like the NRS. The comprehension of pain and when grading on a numeric scale may also vary as a result of different previous pain experiences of the patients and so they do not have the same possibilities to relate their current pain in relation to worst possible pain. With a higher number of participating patients there is a bigger chance that patients who grade their pain very high or very low appear in both treatment groups and the results are more comparable.
Previous studies made on the same topic has shown a pain relief in 75% of the patients treated with RNT as emergency treatment (12-13)compared to 71% in this master study. One of these studies was a retrospective study measuring pain relief in return frequency among the treated patients. However a consequence of this is that some patients with non-sufficient pain relief may have been lost since they may have visited other dentists for further treatment or stayed at home. The other study was prospective, where pain relief was measured on VAS, but did also include patients with a preoperatively pain grading value of 0 which means there was no pain relieving effect to measure. The obtained results in this study showed a non-significant difference in pain relieved patients of 29% between the CMD and RNT treatments. With more
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patients in both groups with the same difference a significance will be possible to obtain. However, the clinical significance of such a difference can be discussed. A frequency of more than 70% of the patients to experience a pain relieving effect might be considered satisfying, especially in relation to benefits such as shorter treatment time at the acute situation. However, it must be considered of utmost importance that the chosen treatment is performed on adequate indications, that the patient is informed about possible complications and that a treatment for CMD is scheduled.
The average preoperative pain level in the CMD group was NRS 6.44 while it was NRS 7.14 in the RNT group. A higher preoperative pain level makes it easier to get a decrease in pain. The decrease in the CMD group was 79% while it was 68% in the RNT group. This indicates that CMD could have a better pain relieving effect than the RNT treatment, however the difference was not significant (p=0.85).
The results obtained in this study showed that 44% of the patients in the CMD group had a postoperative intake of peripheral analgesics while it was 29% in the RNT group. This may be an explanation to the fact that a higher amount of patients in the CMD group compared to the RNT group were pain relieved postoperatively. The higher intake of analgesics in the CMD group may also be a result of the instrumentation done in the root canals and so a bigger tenderness postoperatively than if only necrotic tissue in the crown pulp was removed. Probable reasons to this could be the rinse in the canals that leads to deposition of fluid and bacteria in the tissue outside of the tooth or instrumentation outside of apex leading to a tenderness in the surrounding tissue.
An ethical consideration was made concerning the risks and benefits of this study. Leaving necrotic and infected tissue in a tooth may result in prolonged pain and suffering for the patient. By making a controlled study where patients were given a new appointment within
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two weeks for additional treatment, the benefits of a possible result were considered to outweigh the risks. In a long term perspective it is very important with scientific evidence to be able to choose the treatment that is best for the patient, but also from a cost effective point of view.
The antibiotic resistance is rapidly increasing worldwide and although Sweden has one of the lowest antibiotics subscriptions in Europe, more efforts need to be done to decrease the use of antibiotics in order to slow down the increase of resistant bacterial species (22). The amount of time a dentist has to perform emergency treatment in a necrotic tooth is often limited and so complete chemo mechanical disinfection of the root canals is a too time consuming option and so subscription of antibiotics may be a fast and effective solution for the dentist and the patient in order to control the symptoms until a permanent treatment can be started. In these cases only removal of necrotic and infected tissue in the pulp chamber could be an option as treatment instead of using antibiotics as pain relief in the emergency situation. There are also reasons to believe that treatment performed under time pressure will be of less quality than if done with an adequate amount of time.
From the 1st of January 2013 some changes will be made in the Swedish public dental insurance system, including endodontic emergency treatment. This means that complete chemo mechanical disinfection of the root canal system in necrotic teeth as an emergency treatment will not be part of the insurance compensation and so only removal of tissue in the pulp chamber may be favored due to economic reasons instead of putting the best interest of the patient first.
The obtained results indicate that RNT could be a good emergency treatment for pain relief but that it still has to be done on adequate indications, not when the infection has already spread. It is also important to make sure the patient is well informed about the additional
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treatment needed and to have a new appointment for complete chemo mechanical disinfection for the patient since infected tissue is left in the tooth.
Conclusion
Results from this study show that both CMD and RNT implied a significant pain relieving effect as emergency treatment for teeth with symptomatic apical periodontitis. However, there was no difference between the two treatments concerning the number of patients who obtained satisfying pain relief or in pain relieving effect. The results showed that only removal of necrotic tissue in the pulp chamber could be an adequate emergency treatment option when there are no metastatic infections and when the patient can be given a new appointment in the nearby future for further treatment.
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Figure Legends
Figure 1. Patients treated with complete chemo mechanical disinfection (CMD) and their pre-
and postoperative pain levels measured with Numeric Rating Scale (NRS).
Figure 2. Patients treated with removal of necrotic tissue in the pulp chamber (RNT) and
