|Year : 2021 | Volume
| Issue : 2 | Page : 100-105
In vivo comparison of postoperative pain using two different techniques for local anesthesia in single-sitting root canal treatment
Sumita A Bhagwat, Anchal Mehta, Leena V Padhye
Department of Conservative Dentistry and Endodontics, DYPU College of Dentistry, Navi Mumbai, Maharashtra, India
|Date of Submission||13-Aug-2020|
|Date of Decision||30-Sep-2020|
|Date of Acceptance||21-Nov-2020|
|Date of Web Publication||22-Jun-2021|
Sumita A Bhagwat
Dept of Conservative Dentistry & Endodontics, DYPU School of Dentistry, Nerul, Navi Mumbai
Source of Support: None, Conflict of Interest: None
Aim: This in vivo split-mouth randomized control trial was carried out to study and compare the incidence of postoperative pain associated with single-sitting endodontic treatment using inferior alveolar nerve block and intraligamentary injection as primary anesthetic technique.
Methods: A total of 30 patients with bilateral symptomatic irreversible pulpitis in mandibular molars were selected to be included in the study. In each subject, molar in one quadrant was randomly assigned to Group 1 (intraligamentary injection), and the molar in the opposite quadrant was assigned to Group 2 (inferior alveolar nerve block). The root canal procedures for the patients were carried out in single sittings under rubber dam using hand ProtaperTM system, 2.5% sodium hypochlorite as irrigant alternating with normal saline and obturation by the lateral condensation technique. A questionnaire employing Visual Analog Scale (VAS) for pain assessment was given to the patient and instructions on how to fill the form were given. VAS scores for every tooth treated in every patient were recorded before beginning treatment and after completion of treatment for each tooth. The patients were recalled after 2 days, and the scores were analyzed. The results were tabulated and statistically analyzed for incidence and degree of pain.
Results: Group 1 and Group 2 showed a steady reduction in postoperative pain from 4 h to 48 h as seen in the mean VAS scores. Comparison between the two groups at each time interval showed a difference which was statistically insignificant (P > 0.05).
Conclusion: There is no difference in the incidence of postoperative pain when either inferior alveolar nerve block or intraligamentary injection is employed as the primary technique for achieving anesthesia during single-sitting root canal treatment.
Keywords: Intraligamentary injection, postoperative pain, single-sitting root canal therapy
|How to cite this article:|
Bhagwat SA, Mehta A, Padhye LV. In vivo comparison of postoperative pain using two different techniques for local anesthesia in single-sitting root canal treatment. J Oral Res Rev 2021;13:100-5
|How to cite this URL:|
Bhagwat SA, Mehta A, Padhye LV. In vivo comparison of postoperative pain using two different techniques for local anesthesia in single-sitting root canal treatment. J Oral Res Rev [serial online] 2021 [cited 2021 Aug 4];13:100-5. Available from: https://www.jorr.org/text.asp?2021/13/2/100/319020
| Introduction|| |
Postoperative pain after the completion of root canal therapy continues to be an enigma to clinicians. Pain control in endodontic treatment is of paramount importance and its achievement makes both the dentist and the patient confident and comfortable for future treatment.
The lack of profound anesthesia in teeth with inflamed pulp (symptomatic irreversible pulpitis) is a well-known clinical problem.,,,, It has been suggested that inflammation and infection lower tissue pH, altering the ability of the local anesthetic to provide clinically adequate pain control. Others have suggested that the inflammation alters the peripheral sensory nerve activity and can lead to inability of local anesthetic to prevent impulse transmission.
The presence of pulpitis can be of significance when administering an inferior alveolar nerve block. Lack of success of inferior alveolar nerve block is also possible due to heightened or hypersensitivity of the tooth. The high failure rate of local anesthetic in symptomatic pulpitis has led to the common belief that root canal therapy is a painful dental procedure.
Kaufman et al. in a survey of 93 general dentists found that 90% reported some anesthetic failure during restorative visits over the 5 days preceding the survey. Forty-four percent of dentists reporting initial anesthetic failure noted disrupted or lengthened visits and 11% were unable to complete the procedure they had begun. Malamed states that despite advances in anesthetics and anatomical studies, adequate pain control is a difficult clinical challenge.
The need for single-tooth anesthesia has led to the development of a number of techniques aimed at this goal. Of these techniques, the periodontal ligament injection (called the intraligamentary injection) appears to be the most consistently reliable in achieving clinically adequate pulpal anesthesia. The periodontal ligament injection has been promoted as a primary anesthesia technique only in the last few years. Overall success rates reported in clinical studies have ranged from 81% to 86% when used as a primary technique and from 83% to 92% when used for supplemental anesthesia. To be useful, however, any anesthetic approach must meet several criteria.
A thorough search on PubMed showed that very few randomized control trials have recorded and compared the incidence of postoperative pain when using intraligamentary injection and inferior alveolar nerve block for single-sitting root canal treatment. Hence, an in vivo randomized control trial study with a split-mouth technique was proposed to observe the incidence of postoperative pain perception in patients with chronic irreversible pulpitis when the tooth was preoperatively anesthetized using intraligamentary injection or inferior alveolar nerve block and to compare the observations of both groups after single-sitting root canal therapy was completed.
The study hypothesis proposed was as follows:
Null hypothesis (H0): The incidence of postoperative pain in single-sitting root canal treatment under intraligamentary injection and inferior alveolar nerve block used as primary anesthetic technique is similar.
Thus, if u1 and u2 are the mean values of incidence of postoperative pain for intraligamentary injection group and inferior alveolar nerve block group, then,
H0: μ1 = μ2.
Alternate hypothesis (H1): The incidence of postoperative pain in single-sitting root canal treatment under intraligamentary injection and inferior alveolar nerve block used as primary anesthetic technique is not similar.
H1: μ1 ≠ μ2
| Methods|| |
Thirty adult patients (18–70 years) participated in this split-mouth randomized clinical trial. They were selected from the referred patient pool of the Department of Conservative dentistry and Endodontics, D. Y. Patil University School of Dentistry. The clinical study protocol was reviewed and approved by the University Research Ethical Committee. The trial participants were treated in accordance with the declaration of Helsinki. All were unappointed patients reporting to the clinic for the first time and were in good health as determined by health history and oral questioning. A valid and informed consent was obtained from the patients.
Initial pain readings
Each patient rated his or her preoperative pain reading on a Heft-Parker Visual Analog Scale (VAS) for pain. This was divided into four categories:
- No pain: 0
- Mild pain: 1–3
- Moderate pain: 4–6
- Severe pain: 7–10 (strong, intense, and maximum possible)
The inclusion criteria were as follows:
- Healthy persons (ASA I or II), who required endodontic treatment in bilateral carious mandibular first or second molars with a clinical diagnosis of irreversible pulpitis.
- Teeth without a history of root canal therapy
- Teeth without pus or inflammatory exudate draining through the canal.
- Teeth without anatomic variations such as receded pulp chamber, calcified canals, or sharply curved canals
- Patients not on analgesics or sedative medications before root canal therapy.
- Teeth without sinus tract.
- Teeth with sound periodontal apparatus.
The exclusion criteria were:
- Patients allergic to amide local anesthetics
- Pregnancy or lactation
- Other endocrine or infectious disease
- Moderate to advanced periodontal disease
- Non vital teeth (necrosed)
- Retreatment cases
- Teeth with calcified canals
- Teeth with periapical radiolucency.
To qualify for the study, every patient had bilateral vital mandibular posterior teeth (molars) was actively experiencing pain and had a prolonged response to cold testing with cold ice spray and on electric pulp vitality testing.
Crossover split-mouth study.
Thirty adult participants participated in this study. The sample size was based on the earlier reported data for postoperative pain following single visit root canal treatment. Each patient was selected such that he/she presented with bilateral (36/37 and 46/47) carious pulpal involvement of mandibular molars which required root canal treatment.
All the cases were subjected to vitality testing using electric pulp tester, heat test, and cold test. A preoperative radiograph was taken to check the canals, periodontal tissues and presence of periapical radiolucency. A thorough clinical examination was carried out and a detailed case history was taken. When it was determined that a patient met the criteria of the study, the subject was informed about the nature of the study and their informed consent was taken. Each patient rated their initial pain on a 10 cm VAS with a range of no pain (0 cm) and unbearable pain (10 cm).
Then, random division into two study groups was done. In each subject, molar in one quadrant was assigned to Group 1, and the molar in the opposite quadrant was assigned to Group 2. The allotment of the sides was done randomly. A single operator performed all anesthetic and root canal treatment procedures.
Group 1 received intraligamentary injection 0.4 ml of lignocaine with 1:80,000 epinephrine before the single sitting root canal procedure. Group 2 received inferior alveolar nerve block 1.8 ml of lignocaine 2% with 1:80,000 epinephrine prior to the single sitting root canal procedure of the other tooth in the same patient. The time period between the two anesthetic techniques was maintained at 1 week. Since it was a cross-over study, care was taken to confirm that half the patients received intraligamentary injection as the first anesthetic and the other half patients received inferior alveolar nerve block as the first anaesthetic. Prior to administration of the aaesthetic, a test dose of 1:10 dilution of 2% lignocaine was administered intradermally on the forearm to determine if the patient was allergic to the local anaesthetic. Once it was determined that the patient was not allergic to the anaesthetic, the root canal procedure was initiated.
- Group 1: Patients were administered intraligamentary injection (0.4 ml of Lignocaine) and a single operator performed all of the anesthetic procedures
- Group 2: Patients were administered inferior alveolar nerve block (1.8 ml of lignocaine) and a single operator performed all of the anesthetic procedures. All patients in Group 2 were given long buccal nerve block before starting root canal treatment.
After administration of local anesthesia by the predetermined technique as per group allotment, the tooth was isolated using a rubber dam. Access opening and working length determination were performed by using the technique described by ingle. Working length was also taken using apex locator and was confirmed by taking a radiograph. The root canals were instrumented using the crown down technique with hand Protaper ™ (S1 to F5) up to working length. Canals were irrigated using sterile saline and 2.5% sodium hypochlorite after each instrument used. Obturation was carried out with gutta percha by lateral condensation technique using Zinc Oxide Eugenol-based root canal sealer. All variables besides the local anesthetic technique used were standardized consistently.
Root canal therapy was carried out similarly for all 60 molars (in 30 patients) in single visits. Patients were instructed to rate any occurring pain after the endodontic procedure using VAS. Treatment was deemed successful if no pain or mild discomfort (VAS score of 0 or 1) was felt during the access preparation and instrumentation. Patients were also instructed to contact the clinician in case of severe pain.
A questionnaire was given to the patients at the end of the appointment. Patients were educated about how to assess and record the incidence and severity of pain at 4, 8, 10, 12, 24, and 48 h after the appointment. Patients were also instructed to contact the clinician in case of severe pain and were assured regarding an escape clause for taking pain medication if required.
Participants were recalled after 2 days with the questionnaire that was provided on the day of the treatment. In case the patient had to take medications for severe pain, he/she was disqualified from the study. The ratings from the questionnaires were tabulated. The degree of postoperative pain among the two groups were analyzed using the Shapiro–Wilk test. To test the significance of difference between two groups at different periods, we used paired t-test. Comparisons were considered significant if P < 0.05.
| Results|| |
[Table 1] gives the descriptive statistics for the VAS score readings recorded for Group 1 and Group 2.
|Table 1: Descriptive statistics for the Visual Analog Scale score readings recorded for Group 1 and Group 2|
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[Graph 1] is a line chart showing the mean readings of Group 1 and Group 2 preoperatively, at 4 h, 8 h, 12 h, 24 h, and 48 h.
[Table 2] shows the Wilcoxon signed-rank test that tests the significance of difference between the means of Group 1 and Group 2 patients at 4 h, 8 h, 12 h, 24 h, and 48 h.
| Discussion|| |
Advances in local anesthetics and techniques of administration now allow dental practitioners to deal effectively with the patient experiencing odontogenic pain and in most cases, exceed their expectations.
The intraligamentary injection has been used for a number of years as either a method of obtaining primary anesthesia for one or two teeth or as a supplement to infiltration or block techniques. The technique's primary advantage is that it provides pulpal anesthesia for 30–45 min without an extended period of soft-tissue anesthesia, thus being extremely useful when bilateral treatment is planned. It is useful in pediatric or disabled patients when there is the concern of postoperative tissue trauma to the lip or tongue.
In our study, we strived to note if the incidence of postoperative pain in single sitting root canal procedures was affected by the technique of administration of local anesthesia, i.e., inferior alveolar nerve block and intraligamentary injection by recording the VAS scores before and after treatment.
A cross over (trials in which each subject receives ≥2 treatments in sequence) or split mouth (trials in which each subject receives ≥2 treatments, each to a separate section of the mouth) method was chosen to minimize the potential bias in assignment of treatment and response to therapy. The principal advantage of the split mouth technique is that comparisons are made in the same person as both tested techniques are on the same patient, but opposite sides. Hence, all the factors related to individual pain threshold and emotional aspect of response to pain are eliminated.
The primary prerequisites for the use of split mouth and crossover designs are that: (1) The disease to be investigated is relatively stable and uniformly distributed; (2) the effects of the treatments to be evaluated are short lived or reversible for cross-over studies, or are localized for split-mouth designs.
We recorded postoperative pain for both groups of teeth treated to compare postoperative pain in patients receiving intraligamentary injection and inferior alveolar nerve block after single sitting root canal treatment to assess any difference in postoperative pain in the two groups.
[Table 1] gives the descriptive statistics for the VAS score readings recorded for Group 1 and Group 2.
[Graph 1] is a line chart showing the mean readings of Group 1 and Group 2 preoperatively, at 4 h, 8 h, 12 h, 24 h, and 48 h. From the distribution of the mean readings for each time interval, it graphically appears that the VAS scores for both groups for every time interval are very close to each other. Group 1 (Intraligamentary injection) readings are more gradual in score reduction as compared to Group 2 (inferior alveolar nerve block). This could be attributed to the sustained effect of anesthesia after the block in Group 2 patients for 4 h, at the end of which, the pain score has increased once again and then tapered down.
[Table 2] shows the Wilcoxon signed rank test that tests the significance of difference between the means of Group 1 and Group 2 patients at 4 h, 8 h, 12 h, 24 h, and 48 h.
Interpretation: Since P value for the Wilcoxon test at each measurement, time point is greater than that of 0.05 indicates no significance of difference.
In our study, both Group 1 and Group 2 showed a steady reduction in postoperative pain from 4 h to 48 h as seen in the mean VAS scores. Comparison between the two groups at each time interval showed a difference which was statistically insignificant (P > 0.05).
From these findings, we conclude that the postoperative pain in single-sitting root canal patients is not affected by the technique that is used to deliver local anesthetic, i.e., either intraligamentary injection or inferior alveolar nerve block.
Prama et al., in their study, assessed by VAS the pain during administration of anesthesia and pain during access opening and pulp extirpation in two groups receiving inferior alveolar nerve block and intraligamentary anesthesia. They found that the difference in pain in both procedures was not statistically significant.
Al Hashimi and Ali also studied the pain rating during initial needle penetration, during injection of solution and during pulpectomy in a cross-over study of patients receiving inferior alveolar nerve block and intraligamentary injection during endodontic treatment. Their results showed no statistical significance of difference for either of the groups for all three procedures.
Pradhan et al. compared the efficacy of intraligamentary injection for the extraction of mandibular teeth. They found that the periodontal ligament injection was clinically effective as a primary technique for the extraction of mandibular teeth. Meechan and Ledvinka concluded in their study that Intraligamentary Technique (ILT) could be effectively used as a primary technique or secondary technique. Forum et al. in their study to evaluate histologic changes in intraligamentary injection concluded that ILT caused minimal damage to the periodontal ligament. Lalabonova et al. in their prospective study on 220 general dental practitioners to evaluate the use of ILT showed that 75.91% Bulgarian dental practitioners use ILT in almost all treatments in which 32.94% showed adequate anesthesia. Meechan JG concluded in their review on supplementary routes of LA stated that ILT have advantages where smaller doses are required compared to block or infiltration anesthesia.
While every attempt was made to compare our results with those of similar studies, we were unable to find a previous study that compared postoperative pain in single-sitting root canal treatment after inferior alveolar nerve block and intraligamentary injection were used as two different primary techniques for achieving local anesthesia.
| Conclusion|| |
Based on the results of our study, we conclude that there is no difference in postoperative pain when either inferior alveolar nerve block or intraligamentary injection is employed as the primary technique for achieving anesthesia. We suggest that intraligamentary injection may be commonly used as the primary technique for anesthesia with respect to it having any influence on postoperative pain in single-sitting root canal procedures.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]