2022, Number 1
Frequency of aggravation in cases of endodontic retreatment with different length of obturation
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ABSTRACT
Introduction: complete removal of filling materials and contaminated dentin from the root canal during endodontic retreatment may influence the appearance of an endodontic flare-up. Objective: to determine the frequency of endodontic flare-ups after endodontic retreatment of upper anterior teeth with different lengths of apical filling. Material and methods: thirty-three cases of endodontic failure were chosen for this study. According to the apical length of the initial filling, the subjects were divided into 2 groups: cases closed between 0.0 and 2.0 mm from the radiographic apex (RA) were placed in group A (n = 23) and group B (n = 10) corresponded to cases closed between 2.1 to 6 mm short to RA. Gutta-percha fillings were removed with ProTaper retreatment instruments D1 to D3 (Dentsply-Sirona, Ballaigues, Switzerland) plus chloroform. Subsequently, the root canals were instrumented with K-flexofile files. The reinstrumented cases were filled with Gutta-percha (Higyenic, Coltene Whaledent) and Sealapex (Kerr Sybronendo, WA) during the same appointment. Patients received 400 mg of ibuprofen every 8 hours for 72 hours and recorded postoperative pain at 8, 24, 48, and 72 hours. Flare-up was defined as the appearance of severe pain (pain on the Heft-Parker scale from 114) and/or inflammation. Percentages of positive cases upon palpation and percussion at 72 hours were determined for both groups. Results: two patients presented exacerbation (6%), both of them in group A. Postoperative pain was 21.2% for group A at 8 hours and 9.1% at 48 hours. No statistically significant differences were found in the presence of exacerbation between groups (p > 0.05). Conclusions: the aggravation of endodontic retreatment cases is 6%. The obturation length of cases indicated for endodontic retreatment does not influence the frequency of postoperative aggravation.INTRODUCTION
The success rate in cases of root canals obturated in one appointment reaches 90% after 2.4 years.1 In the majority of conventional cases, root canal retreatment is the first choice when an endodontic failure occurs.2 However, root canal retreatment results in the occurrence of post-endodontic pain in 18% of symptomatic cases when obturation is performed in one appointment.2 Pain after removal of root canal obturation in retreatment cases appears within the first 24 to 48 hours.3 Unfortunately, the postoperative endodontic phase can be uncomfortable and painful for patients. Sathorn et al.4 reported that post-operative pain is present in 3% to 58% of patients. Endodontic aggravation represents the most painful clinical picture and involves an emergency appointment for immediate attention.2,5-7 The frequency of endodontic flare-ups reported in the literature varies widely: Iqbal et al.,8 in a retrospective analysis found an incidence of exacerbation of less than 1%, De Oliveira5 describes an exacerbation of 1.7%, Azim et al.9 of 2.3%, and Onay et al.10 report 3.2% in more than 1,800 treated cases. This acute exacerbation is 9 times more likely to appear in cases with periapical lesions and is more likely to occur when root canal treatment is completed in three or more appointments.8,11 In the case of endodontic retreatment, Azim et al.9 found that retreatment cases can cause 4.4% of endodontic aggravation. On the other hand, Yoldas et al.2 identified 12% aggravation in retreatment cases when dealing with symptomatic cases obturated in one appointment. Debris extrusion may be a factor closely related to postoperative pain.12 This condition can be easily encountered during the root canal obturation removal stage in cases of endodontic retreatment. Rotational instrumentation in the canal system is responsible for the extrusion of dentin debris.13 It is possible that root canals obturated very close to the radiographic apex could favor a greater amount of extrusion of infected dentinal debris during retreatment and thus increase the risk of endodontic aggravation.14 Operative factors related to endodontic flare-ups, such as the radiographic distance of the root canal filling, have not been fully investigated. The aim of this study was to determine the frequency of aggravation after endodontic retreatment of anterosuperior teeth with different apical filling limits.
MATERIAL AND METHODS
Thirty-three cases of endodontic failure and indication for root canal retreatment in anterosuperior teeth of male and female patients, aged 30 to 60 years, without systemic diseases, who attended the Endodontics postgraduate course at the Universidad Autónoma de Tamaulipas were included in the study. The patients gave their informed consent to be included in this investigation. Patients who reported antibiotic consumption 15 days before endodontic retreatment were excluded. Preoperative radiographic images were obtained with a radiovisograph (RVG Trophy® Marne la Vallée, France) using the parallelism technique (Rinn XCP, Dentsply-Sirona) to achieve standardization of the periapical radiographs in orthoradial and mesioradial/distorradial position. Identification of the obturation limit of the cases with endodontic failure was obtained with the "calibrate" tool of the RVG after measuring a 0.4 mm thick orthodontic wire, which was used as a reference. The cases indicated for endodontic retreatment were divided into 2 groups according to their obturation length relative to the RA: group A (n = 23): cases obturated between 0.0 to 2.0 mm and group B (n = 10) cases obturated between 2.1 to 6.0 mm short of the RA. With the patient previously anesthetized and the tooth isolated, tooth restorations were removed until endodontic access was achieved using an Endomate TC piece (NSK, Tokyo, Japan) at 500 rpm with the ProTaper Universal Retreatment instruments (Dentsply/Sirona, Baillaigues, Switzerland) following the manufacturer's indications from D1 to D3. In all cases, 0.2 mL of chloroform was used to facilitate gutta-percha removal. Complete removal of gutta-percha from the root canal was checked using the RVG. The new working length was determined utilizing a Root ZX Mini electronic apical locator (J. Morita Mfg. Corp. Kyoto, Japan) plus the radiographic method. The root canals were patented with a K Flexofile #.10 file (Maillefer, Ballaigues Switzerland) and instrumented by a single operator (DOL) with K Flexofile files to an apical caliber between #.55 to #.60. Between each instrumentation sequence, the canals were irrigated with 2 ml of 2% NaOCl. After instrumentation, passive ultrasonic irrigation (U File 33mm, #25, NSK) was used 1 mm short of the working length for 1 minute. This was followed by irrigation with 2 ml of 17% EDTA (VistaDental Products, Racine, WI) for 1 minute, the chelating agent was removed with 4 ml of saline, and a final irrigation with 10 ml of 2% NaOCl for 2 minutes. The cases were obturated in one appointment using the classic lateral condensation technique and Sealapex sealer. Once the endodontic retreatment was completed, the distance of the new obturation limit to the radiographic apex was recorded as described above and in all cases, it was between 0.35 to 1.74 mm short of the RA. Ibuprofen 400 mg capsules were prescribed every 8 hours for the endodontic postoperative period. For registering postoperative parameters, a format for recording pain employing the Heft-Parker visual analog scale15,16 was explained and given to the patient at 8, 24, 48, and 72 hours postoperatively. The patient was summoned at 72 hours to determine the pain on percussion and palpation in both groups. Flare-up was defined as the appearance of severe pain and/or swelling (Heft-Parker scale pain from 114) immediately at the end of the retreatment appointment and up to 72 hours postoperatively. Descriptive percentages were obtained for pain in different postoperative periods, pain upon percussion and palpation, and pain aggravation. Mean and standard deviation was obtained for age and pain intensity at 72 hours. χ2 was used for the analysis of flare-ups and pain periods as well as a Mann Whitney Wilcoxon U test for the analysis of pain intensity with an alpha of 0.05 in the IBM SPSS Statistics version 24 statistical program.
RESULTS
The average age of the sample was 42.7 ± 6.8 years. Males presented 42.1 ± 6.9 and females 43 ± 7.1 years. The preoperative results of the study are shown in Table 1.
The obturation limit of endodontic treatment before retreatment was 1.01 ± 0.43 mm in group A and 2.71 ± 1.01 mm to the RA in group B. There were 2 flare-up cases (6%) in the entire sample. Both cases were observed in group A. Table 2 presents postoperative pain observed in different periods.
The intensity of postoperative pain identified in the whole sample at 72 hours was 15.7 ± 34.1, positive percussion was present in 30.3%, and positive palpation in 9.09%. Table 3 reports the results of these parameters according to the study group.
DISCUSSION
Pain is a subjective variable since it depends on the perception that each individual has of the sensation of pain that he/she experiences. The search for parameters to quantify this postoperative event has led to the establishment of quantitative measurement scales such as the Heft-Parker scale used in the present study.
In this investigation, the influence of the obturation limit in cases of endodontic failure and the appearance of endodontic flare-ups was assessed. The endodontic flare-up found in the study was 6%. This result is similar to the one reported by Onay et al.10 and Azim et al.,9 corroborating that flare-up is not a frequent postoperative effect. Although the flare-up cases were identified in the group of patients with an initial endodontic obturation between 0.0 to 2.0 mm at RA, it was not determined statistically that the obturation limit influences the frequency of flare-up and postoperative pain in root canal retreatment. In this regard, Hepsenoglu et al.17 reported less pain intensity in retreatment cases obturated in one appointment compared to two appointments with intra-canal medication. Post-endodontic pain occurred in the group of patients with endodontic fillings between 0.0-2.0 mm short of RA in 21 and 13% at 8 and 24 hours, respectively. Our results suggest that re-instrumentation and re-filling in one appointment do not play an important role in the frequency of postoperative pain aggravation and intensity since, as pointed out by Manfredi et al.,18 retreatment cases filled in one appointment do not present more pain than those filled in two sessions. We agree with Manfredi et al.18 in the sense that the obturation of retreatment cases in one appointment is convenient in terms of time not only for the patient but also for the dentist.
Another factor to be considered in the frequency and intensity of postoperative pain is the extrusion of biological material that may be caused by the instruments during dentin removal for retreatment. In this regard, Eyuboglu et al.19 observed that instruments with rotary movement cause less incidence of postoperative pain at 72 hours than those with reciprocating action when performing endodontic retreatment in one session. In general, although no statistically significant differences in postoperative pain were observed between the study groups, the frequency and intensity of pain were higher in cases obturated between 0.0-2.0 mm at RA. In our study, ProTaper retreatment rotary instruments were used in coronal-apical sequence; it is possible that the rotary action may generate a gradual dislodging action of dentin and gutta-percha/sealer toward the coronal portion through the helical angle of the rotary instruments when the obturations of cases with endodontic failure are short to the RA where the apical foramen seems to be at a safe distance. However, when the obturation of cases with endodontic failure is between 0.0-2.0 mm to the RA, the perception of postoperative pain may be different. Although no statistically significant differences between groups were identified, a possible explanation for the observation of acute cases and higher frequency and intensity of postoperative pain in the periods of 8 and 24 hours in the group of teeth obturated between 0.0 to 2. 0 mm to the RA is that the mechanical action of the ProTaper retreatment instruments might extrude contaminated material, given the inevitable insertion and progressive advance of this instrument towards the apex where it can compact and push dentin debris from the interior of the root canal towards the apical foramen and periapical tissues.
To facilitate the removal of gutta-percha from the obturated root canals, a solvent (chloroform) was used in our study. In this regard, Ozgur et al.20 reported no difference in the postoperative pain observed in retreatment cases finished in one appointment using ProTaper retreatment with or without solvent. A postoperative disadvantage of one-appointment obturation in retreatment cases that initially had a limit of obturation between 0.0-2.0 mm from the RA is that at 72 hours there are about 30% more cases with positive percussion than in retreatments with obturations initially short 2.1 mm or more from the RA. It seems that the endodontic failure of uniradicular teeth obturated between 0.0-2.0 mm from the RA does not have an influence on the flare-up after root canal retreatment. However, further studies will be necessary to give certainty to the knowledge generated by this research and to delve into different factors, not only operative, that may be associated with the appearance of an endodontic flare-up.
CONCLUSIONS
The flare-up incidence of cases with endodontic retreatment was 6%. The obturation length of upper anterior teeth indicated for endodontic retreatment does not influence the frequency of postoperative flare-ups. Postoperative pain and pain upon palpation and percussion at 72 hours is not different in cases of retreatment with different obturation length from the RA.
REFERENCES
Hobeich P, Simon S, Schneiderman E, He J. A prospective, randomized, double-blind comparison of the injection pain and anesthetic onset of 2% lidocaine with 1:100,000 epinephrine buffered with 5% and 10% sodium bicarbonate in maxillary infiltrations. J Endod. 2013; 39 (5): 597-599. doi: 10.1016/j.joen.2013.01.008.
AFFILIATIONS
1 Egresado del Posgrado en Endodoncia, Facultad de Odontología, Universidad Autónoma de Tamaulipas.
2 Facultad de Odontología de la Universidad Autónoma de Tamaulipas, Tampico Tamaulipas México.
CORRESPONDENCE
Rogelio Oliver Parra. E-mail: roliver@docentes.uat.edu.mxReceived: Junio 2020. Accepted: Abril 2021.