Historically, the public has associated dental treatment with pain.[
] Due to pharmacological, behavioral, and practice management issues, management of pain is a challenge, as well as an opportunity for the dentist.[ 1 ] Irrespective of the dentist’s skills, root canal treatment can be performed only with proper pain control,[ 2 ] and it can be achieved only by effective local anesthesia (LA), which is a must for pain control. 3
Lidocaine was introduced in the late 1940s, and because of its safety and effectiveness, it not only became the most common dental local anesthetic but also became the gold standard for comparison with newer local anesthetics.[
] However, while anesthetizing teeth with 4 irreversible pulpitis (IP), lidocaine proved to be less effective, and thus created a need to produce an anesthetic agent better than lidocaine. This led to the development of articaine which has better lipid solubility and efficacy.[ 5 , ] 6
To determine the effectiveness of 4%
articaine, various researches in different concentrations, volumes, and techniques of use, were carried out. Most of the studies have been done to evaluate the anesthetic efficacy on mandibular posteriors, and very few studies have been done for maxillary first molars, which further needs investigation. Hence this study needs to be done to know how effective 4% articaine is in anesthetizing maxillary first molar with IP using buccal infiltration (BI) and buccal plus palatal infiltration (BPI) techniques. MATERIALS AND METHODS
In this study, after obtaining ethical clearance from College Review Committee, the research was registered with CTRI
(CTRI/2016/09/007286). One hundred adult volunteer subjects with symptomatic IP of maxillary first molar participated in this study. Patients in the age group of 16-45 years having moderate to severe lingering pain with cold test, without any periapical radiolucency, who have not consumed any medications in the last 12 hours, and who are able to understand the Heft-Parker Visual Analogue Scale (HP VAS) were included in this study. All patients having systemic conditions, pain in any other maxillary posteriors in the same quadrant, and swelling in relation to the tooth in question were excluded.
The research procedure was properly explained to the patients in their known language. Informed written consent was obtained from each patient. The pain scale was explained precisely. In the current study, on HP VAS, 0 mm was considered no pain, >0 mm to ≤54 mm was considered mild pain, >54 mm to <114 mm was considered moderate pain, and ≥114 mm was considered severe pain. After administration of LA, at any step, if a patient rated pain between 0 mm and ≤54 mm, it was considered successful anesthesia. However, if patient rated pain between >54 mm and ≥114 mm, it was considered failed anesthesia.
All 100 adult patients were randomly and equally divided into two subgroups. In group 1, 4%
articaine with 1:100,000 epinephrine [Septonest; Septodont India, New Delhi, India] was deposited using submucosal BI technique. Using pre-operative radiographs, a tentative length of the tooth was determined, and accordingly a rubber stopper was placed on the needle. For 1 min, topical anesthetic gel [Xylocaine 2% jelly, Astrazeneca, India] was applied buccally to the involved tooth, using cotton tip applicator. Then, keeping the bevel toward the bone, a 27-gauge needle [Septoject; Septdont India, New Delhi, India] was slowly advanced into the buccal alveolar mucosa until the stopper corresponded with the level of buccal cusps of the molar. Following this, aspiration was performed, and at the rate of 1 ml/min, entire cartridge of 1.8 ml solution was deposited. Following anesthesia, all patients recorded their pain again after 10 min of injection. None of the patients reported pain more than 54 mm; otherwise, it would have been marked as failure.
After the application of the rubber dam, access opening was initiated. Patients were instructed that if they felt any pain during the procedure they will raise their left hand, and treatment will be stopped and then they will rate the pain. After rating the pain, the extent of the procedure was recorded. The same procedure was repeated for group 2 patients, in which 0.5 ml was infiltrated over the palatal root apex, and 0.9 ml was infiltrated on the buccal aspect. Rest of the procedure followed was similar to group 1. The findings were recorded onto a Microsoft Excel Sheet for statistical evaluation.
In group I [
Figure 1], 23 (46%) patients, 21 (42%) patients, and 6 (12.0%) patients were in the age group of 20–30 years, 31–40 years, and 41–50 years, respectively. Thus, the majority of the patients in group I were young between 20 and 40 years. In group II [ Figure 1], 26 (52%) patients, 20 (40%) patients, and 4 (8%) patients were in the age group of 20–30 years, 31–40 years, and 41–50 years, respectively. In this group too, most of the patients were between the age group of 20–40 years. In group I [ Figure 2], there were 32 (64.0%) males and 18 (36.0%) females, while in group II [ Figure 2] there were 30 (60.0%) males and 20 (40%) females. In both groups, there was a male preponderance. Figure 1:
Age wise distribution of patients
Gender wise distribution of patients
No statistically significant difference was found between both groups, when mean pain scores at different stages (pre-operative, 10 min after LA injection and during root canal treatment procedure) were compared using unpaired t-test (
P > 0.05) [ Table 1]. The maximum mean pain score in both groups was measured as the maximum pain the patient had felt during the procedure, that is, at dentin, at pulp, or during the file insertion. Accordingly the maximum pain was compared. The maximum pain felt by patients in group I was 12.2 ± 34.9 mm, while in group II it was 8.8 ± 31.6 mm. Though the maximum mean pain score was more in group I as compared to group II, no statistically significant difference ( P > 0.05) was found [ Table 1]. In both groups, there were four patients with unsuccessful anesthesia [ Table 2]. Two sample z-test to compare sample proportions was performed to calculate the significance between group I and group for each pain type (moderate pain and severe pain), and no significant difference was found in the number of subjects experiencing moderate and severe pain [ Table 3]. Table 1:
Mean pain scores preoperatively, at 10 min after injection and at different tooth location during procedure in Group I and Group II
Comparison of number of unsuccessful anesthesia in test groups
Comparison of unsuccessful cases in both groups
In this study,
articaine was used because of its better anesthetic efficacy, as shown by Kanna et al.,[ ] Evans 7 et al.,[ ] and Srinivasan 8 et al.[ ] 9 Articaine, introduced in 1969,[ ] is a safe local anesthetic, and it provides an improved local anesthetic effect.[ 4 ] It has medium duration and with high power of diffusion in oral tissue,[ 9 ] it provides successful anesthesia when other anesthetics fail.[ 10 ] It is an amide local anesthetic, and because of the presence of a thiophene ring and an additional ester group, it is different from other agents of its group.[ 5 ] It has increased lipid solubility due to thiophene group, and biotransformation of 4 articaine occurs in both plasma and liver, because of the presence of the ester group. Articaine is delivered as 4% solution and compared to other amide local anesthetics it can be used in higher concentration, because it provides improved analgesic efficacy with reduced systemic toxicity.[ ] This allows injection of smaller volumes and thus minimizes the injection-induced pain. 5
Maxillary molars were chosen in the present study because various studies have been done on mandibular posteriors with IP, but very few studies have been done for maxillary molars, which further needs investigation.[
] For the standardization of the study, first molars were chosen, as in 96.8% maxillary first molar, a consistency of three roots is found.[ 9 ] Considering the nerve supply of the maxillary molars, the pulp and periodontium of maxillary molars are innervated by posterior superior alveolar (PSA) nerve, and sensitivity to the palatal mucosa is from palatal nerve. In this study, supraperiosteal injection (infiltration) was used rather than PSA because the tooth under examination was maxillary first molar, that is, a single tooth. PSA is recommended for the management of several molar teeth in one quadrant.[ 11 ] Furthermore, not only PSA does not anesthetize mesiobuccal root of maxillary first molar in 28% of the cases, but also has been found to be associated with some adverse events, like diplopia, hematomas.[ 12 ] 13
The supraperiosteal injection (infiltration) is indicated whenever dental procedures are confined to a relatively circumscribed area in either the maxilla or mandible.[
] In supraperiosteal technique, the anesthetic solution is placed adjacent to the periosteum of the alveolar bone overlying the apex of the tooth. This technique is successful in up to 95% of the cases, as the maxilla is relatively porous and has a thin cortical plate where the anesthetic solution is able to penetrate the bone and anesthetize terminal nerve fibers of the superior dental plexus.[ 12 ] Supraperiosteal injection proves to be of great success in maxillary arch.[ 14 ] Also maxillary BI anesthesia is a commonly used technique for providing pulpal anesthesia for maxillary teeth.[ 12 ] Moreover, Aggarwal 13 et al.[ ] reported that PSA has no advantage over infiltration anesthesia. 13
In the current study, in group II, a
palatal infiltration, which is actually very painful and traumatic because of close bond between palatal mucosa and its underlying periosteum,[ ] was given along with the BI. In our study, we found that group II (BPI) has no statistically significant difference compared with group I (BI). 12
In this study, patients with IP were taken, because inflammation of the pulp not only alters the resting potentials but also decreases the excitability thresholds of the pulpal nerves and therefore is eight times more difficult to anaesthetize as compared to normal pulps.[
] Inflammation plays an important role and is responsible for hyperalgesia and failure of LA.[ 13 ] Various mechanisms have been propped that can increase the chance of failure of local anesthetics in inflamed pulp.[ 14 ] But, the main reason for failure in IP cases is inflammation-induced acidosis that causes “ion trapping” of local anesthetics, and thus not allow the molecule to cross the cell membrane. Furthermore, the peripheral vasodilation due to mediators of inflammation would increase the rate of systemic resorption and reduce the concentration of local anesthetics.[ 15 ] 16
In our study, success rate of 92% was found in both groups. This is not in accordance with Aggarwal
et al.[ ] who found a success rate of only 54% with BI, and a success rate of 70% with BPI. This difference might be because, in the present study, we have used 4% 13 articaine whereas Aggarwal et al.[ ] had used 2% lidocaine. However, the findings of the present study support the study done by Aggarwal 13 et al.,[ ] who found no statistically significant difference between the success rates of BI and BPI, and Guglielmo 13 et al.[ ] who found that adding 17 palatal infiltration to BI has no significant effect on the success rate. CONCLUSION
Within the limitations of the present study, we can conclude that anesthetic efficacy of BI with 4%
articaine is comparable to BPI for maxillary first molars with IP, thus obviating the need for additional painful palatal infiltration. However, further research is required. Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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