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Effect of warming anesthetic on pain perception during dental injection: a split-mouth randomized clinical trial

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Local and Regional Anesthesia
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Background The purpose of this study is to determine the effectiveness of warming anesthesia on the control of the pain produced during the administration of dental anesthesia injection and to analyze the role of Transient Receptor Potential Vanilloid-1 nociceptor channels in this effect. Patients and methods A double-blind, split-mouth randomized clinical trial was designed. Seventy-two volunteer students (22.1±2.45 years old; 51 men) from the School of Dentistry at the Universidad Austral de Chile (Valdivia, Chile) participated. They were each administered 0.9 mL of lidocaine HCl 2% with epinephrine 1:100,000 (Alphacaine®) using two injections in the buccal vestibule at the level of the upper lateral incisor teeth. Anesthesia was administered in a hemiarch at 42°C (107.6°F) and after 1 week, anesthesia was administered by randomized sequence on the contralateral side at room temperature (21°C–69.8°F) at a standardized speed. The intensity of pain perceived during the injection was compared using a 100 mm visual analog scale (VAS; Wilcoxon test p<0.05). Results The use of anesthesia at room temperature produced an average VAS for pain of 35.3±16.71 mm and anesthesia at 42°C produced VAS for pain of 15±14.67 mm (p<0.001). Conclusion The use of anesthesia at 42°C significantly reduced the pain during the injection of anesthesia compared to its use at room temperature during maxillary injections. The physiological mechanism of the temperature on pain reduction could be due to a synergic action on the permeabilization of the Transient Receptor Potential Vanilloid-1 channels, allowing the passage of anesthetic inside the nociceptors.
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CLINICAL TRIAL REPORT
open access to scientific and medical research
Open Access Full Text Article
http://dx.doi.org/10.2147/LRA.S147288
Effect of warming anesthetic on pain perception
during dental injection: a split-mouth randomized
clinical trial
Pedro Christian Aravena1,2
Camila Barrientos1
Catalina Troncoso1
Cesar Coronado3
Pamela Sotelo-Hitschfeld4
1Department of Dentistry,
Universidad Austral de Chile, Valdivia,
Chile; 2Department of Dental Implant
Surgery, São Leopoldo Mandic School
and Dental Institute, Campinas, SP,
Brazil; 3Faculty of Health Science,
School of Medicine, Universidad
Autónoma de Chile, Santiago,
Chile; 4Department of Center for
Interdisciplinary Studies on Nervous
System (CISNe), Universidad Austral
de Chile, Valdivia, Chile
Background: The purpose of this study is to determine the effectiveness of warming anesthesia
on the control of the pain produced during the administration of dental anesthesia injection and
to analyze the role of Transient Receptor Potential Vanilloid-1 nociceptor channels in this effect.
Patients and methods: A double-blind, split-mouth randomized clinical trial was designed.
Seventy-two volunteer students (22.1±2.45 years old; 51 men) from the School of Dentistry at
the Universidad Austral de Chile (Valdivia, Chile) participated. They were each administered
0.9 mL of lidocaine HCl 2% with epinephrine 1:100,000 (Alphacaine®) using two injections in
the buccal vestibule at the level of the upper lateral incisor teeth. Anesthesia was administered
in a hemiarch at 42°C (107.6°F) and after 1 week, anesthesia was administered by randomized
sequence on the contralateral side at room temperature (21°C–69.8°F) at a standardized speed.
The intensity of pain perceived during the injection was compared using a 100 mm visual analog
scale (VAS; Wilcoxon test p<0.05).
Results: The use of anesthesia at room temperature produced an average VAS for pain of
35.3±16.71 mm and anesthesia at 42°C produced VAS for pain of 15±14.67 mm (p<0.001).
Conclusion: The use of anesthesia at 42°C significantly reduced the pain during the injection
of anesthesia compared to its use at room temperature during maxillary injections. The physi-
ological mechanism of the temperature on pain reduction could be due to a synergic action on
the permeabilization of the Transient Receptor Potential Vanilloid-1 channels, allowing the
passage of anesthetic inside the nociceptors.
Keywords: pain, dental anesthesia, maxillary, lidocaine, trigeminal nerve, clinical trial, TRP
channel
Introduction
The use of local anesthesia in dentistry is a critical component in dental treatment
given patients’ fear of injections and pain caused during the injection of anesthesia.1
This act causes inherent tissue damage during penetration of the needle and injection
of anesthetic fluid,2 releasing proinflammatory mediators and increasing the pressure in
the submucosal tissue that activates nociceptor terminals, sensitizing the puncture site.3
The methods studied to control this situation include the use of nerve block
injections, lower injection speeds at 1 cartridge/min4,5 and the compression of tissues
adjacent to the puncture site.5 However, all these methods are operator-dependent.
One method proven to reduce the perception of pain is to warm local anesthetics.6–8
Reports in dentistry are inconsistent. Rogers et al9 showed that the warmed anesthetic
injection was significantly more comfortable than one at room temperature. However,
Correspondence: Pedro Christian
Aravena
Rudloff Street 1640. Valdivia 5110474,
Chile
Tel +56 63 222 1205
Fax +56 63 229 3751
Email paravena@uach.cl
Journal name: Local and Regional Anesthesia
Article Designation: CLINICAL TRIAL REPORT
Year: 2018
Volume: 11
Running head verso: Aravena et al
Running head recto: Effect of warming anesthesia in pain perception
DOI: http://dx.doi.org/10.2147/LRA.S147288
This article was published in the following Dove Press journal:
Local and Regional Anesthesia
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Aravena et al
Oikarinen et al10 and Ram et al11 showed that the injection of
anesthetic at body temperature did not present any significant
differences in the subjective perception of pain.
A systematic review by Hogan et al12 decided on the
effectiveness of heating anesthetics to control pain during
the injection at various areas of the body, suggesting that
this effect be analyzed for dental anesthetic injections. This
effect would contribute to reducing the anxiety levels, thereby
causing greater comfort during treatment and a better dentist–
patient relationship.13,14
Therefore, the aim of this study is to determine the
effectiveness of the use of anesthesia at 42°C in the percep-
tion of pain during the administration of dental anesthesia
compared to its use at room temperature (21°C) during the
maxillary injection technique. In addition, the physiological
role of the nociceptor membrane channels will be analyzed
in terms of the effect of warming the anesthetic on reducing
the perception of pain.
Patients and methods
Study design and sampling
A double-blind, split-mouth randomized clinical trial was
conducted according to Consolidated Standards of Reporting
Trials (CONSORT) guidelines and was reviewed and approved
by the Ethics and Research Committee of the Valdivia Health
Service, Government of Chile (no. 075/2015). The study is
registered under clinical study # ISRCTN78906795.
Students from the School of Dentistry at the Universidad
Austral de Chile, Valdivia, Chile participated. The students
selected had American Society of Anesthesiologists I health
status, were aged between 18 and 35 years, were of both gen-
ders, and had not undergone any treatment with nonsteroidal
anti-inflammatory drugs in the 2 months prior to the study
and were without dental pain or infection at the puncture site.
Before starting the study protocol, all participants provided
written informed consent approved by the ethical committee.
The sample size was based on a pilot study15 who showed
a mean difference of 18.5 points on the visual analog scale
(VAS) using local anesthetic at 42°C. Considering a 5% level
of significance, a study power of 90% and including 25% of
the sample in case of loss of observers, a total of 70 subjects
were estimated.
Temperature control of the anesthetic
cartridge
To warm the anesthesia, a researcher (CB) undertook a pilot
study with 20 cartridges of anesthesia. A baby bottle warmer
was used (Phillips Avent®, Amsterdam, the Netherlands)
similar to that used in previous reports.6,11,12 The cartridge of
anesthetic was left in a hermetically sealed plastic bag that
was placed in the warmer containing 300 mL of cold water
(21°C). Using the maximum power of the apparatus, the
anesthetic fluid reached 42°C (107.6°F) in 3 min 50 seconds.
Randomization and use of anesthetic
To determine the chronological order of injection with the
anesthesia warmed to 42°C, a simple randomization func-
tion of the program MS Excel 2013 (Microsoft Corpora-
tion, Redmond, WA, USA) was used. The first injection
was applied on the subject’s dominant side (left/right) and
the temperature used depended on the random number
(even=room temperature; odd=42°C) with the participant
blinded to it. For anesthetic infiltration to the anterosuperior
alveolar nerve, a researcher (CT) with more than 10 years of
experience in dental anesthetic techniques administered the
anesthetic according to the steps and technique described by
Malamed.4 The injection point was placed in the mucobuc-
cal fold apically between teeth #6 and #11 using a 30G short
needle ( Septoject XL; Septodont, Saint-Maur-des-Fossés,
France) and injecting 0.9 mL of the anesthetic (Alpha-
caine100®; Nova DFL, Taquara Rio de Janeiro, Brazil) at
a speed of 0.15 mL/second.16 Immediately after the injec-
tion, a second researcher presented the patient with a 100
mm VAS (0=absence of pain; 100=unbearable pain) asking
“How much pain did you feel as the anesthesia was being
administered?”. The pain indicated with a finger or verbally
was recorded. There was a 1-week washout period after the
first injection and the second injection was administered on
the contralateral side of the maxilla with the other anesthetic
temperature according to the described random sequence.
Data analysis
The temperature used (42°C and room temperature) was the
independent variable and the dependent variable was the
level of pain perceived during the anesthetic injection. To
verify the effectiveness of warming the anesthetic to 42°C
vs. room temperature (21°C), the parametric behavior of the
pain records in both study groups was analyzed by a third
blinded researcher (PCA) using the Shapiro–Wilk test. Then,
the median, SD (±) and 95% CIs of the VAS of all the subjects
in both study groups were compared using the corresponding
test according to the distribution of the values (Student’s t-test
or Wilcoxon test; p<0.05) using STATA v10.0 (StataCorp LP,
College Station, TX, USA).
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Effect of warming anesthesia in pain perception
Results
In total, 83 volunteer students participated between July
and September 2015. Based on the criteria for selection and
after the 1-week washout period, 11 students were excluded
(Figure 1). Finally, 72 subjects (51 men) were analyzed, who
had an average age of 22.1±2.45 years (range 18–29 years;
men: 21.9±2.3 years, women: 22.3±2.6 years).
The distribution of normality of the pain records in the
two groups was found to be nonparametric (p=0.001). The
level of pain perceived according to the VAS by the 42°C
group was significantly lesser that that of the room tempera-
ture group (p<0.001; Table 1).
Discussion
According to the hypothesis raised here, it was verified that
the use of anesthesia at 42°C significantly reduced pain
compared to that at room temperature during the injection
of local anesthesia using the maxillary infiltration technique.
Our results are consistent with previous reports on the
effect of warming the anesthesia on the perception of the
pain in the trigeminal territory: using 2% procaine 1:80,000
epinephrine (Palex Medical Laboratories, Madrid, Spain) at
43°C in plastic surgery;6 1% lidocaine 1:200,000 epineph-
rine (Astra Laboratories, Cambridge, UK) at 38°C in cheek
or face anesthesia17 and 2% lidocaine (Astra Laboratories)
with 5 mL 0.5% bupivacaine at 37°C in cataract surgery.18 In
dentistry, special attention is paid to this issue, considering
that most dental procedures require local anesthesia. Rogers
et al9 showed that the use of anesthesia at body temperature
was more comfortable than at room temperature. Neverthe-
less, other reports10,11 have not demonstrated a positive effect
and their methodology does not permit comparison with
our results, mainly due to the lack of data on the method of
warming of the anesthetic and to the use of scales for facial
expression, movements of extremities or perceived crying.11
On the other hand, there are studies that even suggest not
warming the anesthetic cartridges because the drug and the
vasoconstrictor inside could degrade, which would decrease
its effectiveness.4,19 Although the manufacturer’s instructions
encourage keeping the cartridges at room temperature, there
are reports that show that lidocaine can tolerate repeated
sterilization by autoclave20 and that epinephrine can withstand
repeated warming with no appreciable degradation,21 even at
extreme temperatures of up to 51.7°C for an accumulated time
of 13.25 hours.22 However, this information is inconclusive
in dentistry given the paucity of technical reports based on
electronic data that can verify the preservation of anesthetic
compounds inside the cartridge at different temperatures.
Figure 1 CONSORT ow diagram.
Note: The subjects participated in both study groups (split mouth) with a 1-week washout.
Abbreviation: CONSORT, Consolidated Standards of Reporting Trials.
Anesthesia 42ºC
Assessed for eligibility (n=93)
Randomized (n=87)
Excluded (n=6)
Not meeting inclusion criteria (n=5)
Declined to participate (n=1)
Anesthesia room temperature
Allocated to intervention (n=87)
Lost to follow-up (n=5) Lost to follow-up (n=5)
Discontinued intervention (did not return n=5)
Analyzed (n=72) Analyzed (n=72)
AnalysisFollow-up Allocation Enrollment
Received allocated intervention (n=87)
Allocated to intervention (n=87)
Received all allocated intervention (n=87)
Discontinued intervention (did not return n=5)
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Aravena et al
Role of temperature on the effect of
anesthesia in Transient Receptor Potential
Vanilloid-1 (TRPV1) channels
The role of local anesthetics is to prevent a change in the
propagation of the nerve impulse along the nociceptor by
blocking sodium channels. The liposoluble nature of lido-
caine is a result of an aromatic ring and the tertiary form of
the terminal amine;23 this that it spreads freely through the
plasma membrane, reaching the intracellular fluid where it
can perform its function. It can be inferred from the collected
data that warming the anesthesia to 42°C may aid the mol-
ecule in penetrating the nociceptor, thereby contributing to a
faster blocking of the sodium channels, impeding propagation
of the pain signal. This phenomenon could be explained by
two possible mechanisms: first, an increase in the fluidity of
the lipid membrane, which may allow lidocaine to cross the
membrane more easily, reaching the effective concentration
to produce analgesia more quickly and the second mecha-
nism may be related to the presence of TRPV1 channels24
expressed densely in the trigeminal tissue.25
TRPV1 is the founding member of a subfamily of heat-
sensitive TRP channels that allow primary afferent nociceptors
and other cell types to detect changes in the environment.26
Initially called capsaicin receptor (VR1), TRPV1 is not only
activated in the presence of vanilloid compounds, such as the
active compound in chili pepper, but also in the temperature
range that is close to harmful, over 42°C.24 Thus, TRPV1 acts
as a polymodal integrator of chemical and thermal signals,
modulating the excitability of the nociceptor to changes in the
local tissue environment.25 Once the TRPV1 has been acti-
vated, the pore is wide enough to permeate the large cations.
When more than one factor activates the channel, a synergic
action is exerted that causes a strong activation of TRPV1,
which increases the permeabilization of the large cations.26–28
Limitations
The limitations of our study are related to patient–dentist
variables. It must be considered that the subjects were healthy
volunteers who do not necessarily represent the population
that requires local anesthesia. In addition, the description of
the subjective variable as pain using a VAS is dependent on
the emotional state and previous history of the subjects to the
perception of pain and the injection of anesthetics. However,
this is recognized as a valid and reliable method in clinical
use.29 The control of the speed and anesthetic technique var-
ies according to the dentist’s experience, the reason for the
anesthesia and the anatomy of the puncture site, a situation
which generates different levels of pain perception condi-
tioned mainly by the patient’s previous experience with dental
treatment.13,14 In any case, it is advisable to inject the anes-
thetic slowly4,16 since it has been proven that the sensitivity
of the nociceptors not only depends on the type of chemical
agent but also on the mechanical effects of the injection site
and the speed and volume of the injection.2 Despite these
limitations, we have controlled the possible risks of bias
set out by Hogan et al,12 such as adequate generation of
the intervention sequence, masking of the participants and
analysis of results.
Conclusion
In conclusion, warming the anesthetic cartridges to 42°C
demonstrated a reduction in pain during the injection of
anesthesia in the maxillary infiltration technique compared to
the anesthesia used at room temperature. These results con-
tribute to the need to use an easy and replicable method that
can control pain during dental injection, so as to reduce pain
and anxiety levels during dental treatment using domestic
portable equipment such as incubators with a thermostat or
baby bottle warmer. It is suggested that there should be future
analyses of patients with pulpal pathologies and discussion
based on the physiological and pharmacologic foundations
that can explain this clinical result.
Disclosure
The authors report no conflicts of interest in this work.
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Table 1 Level of pain perceived by the study group according to the visual analog scale of pain
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... Although the main advantage of IANB is anesthesia over an immense area, it has the highest amount of patient distress when compared to other injection methods. [3] Regardless of the constant development of different innovative dental injection techniques, the injection of LA still results in pain and discomfort for many children; and has been labeled as a leading reason for dental anxiety. [4] It is a fact that factors other than specific procedures affect the effectiveness of local anesthetics, such as pH, pKa, lipid solubility, protein binding, and length of the intermediate chain. ...
... [9][10][11][12] These methods, which depend on the operator, have not been able to totally eradicate the fear and anxiety related to dental care among children. [3] Initially described by Boggia, warming the LA solution to body temperature (37°C) before injecting is one technique that has been shown to minimize pain. [13] It has been proven that employing this strategy reduces discomfort when local anesthetics are being injected during ophthalmological and plastic surgical procedures. ...
... To prewarm the solution, a baby bottle warmer was used (Luv Lap Royal baby bottle warmer, India) similarly to that used in previous literature. [3,22,23] A pilot study with 20 vials was done before confirming and formulating the desired temperature (42°C). Each time, 2 mL of LA (2% lignocaine anesthetic solution with 1:80,000 epinephrine, Lignox® 2% A, Indoco Remedies Ltd., Mumbai, India) was drawn from the local anesthetic vial and dispensed in an empty LA vial. ...
Article
Full-text available
Background Both precooling the site and injecting a warm anesthetic solution have proven to be efficient in reducing pain individually. However, there is insufficient data on evaluating the efficiency of precooling the site of injection along with the simultaneous administration of a warm local anesthetic solution on the same site in a single patient. Aim The aim of this study was to evaluate and compare the efficacy, pain perception, hemodynamic changes, and adverse effects of a warm local anesthetic solution injected on precooled injection sites using 2% lignocaine with the conventional local anesthetic technique during inferior alveolar nerve block in 7–9-year-old children. Methods A split-mouth, double-blinded, randomized clinical trial was conducted on 70 children who received 2% lignocaine with either technique A or B during the first or second appointment of the treatment procedure. The pain perception, anesthetic efficacy, pulse rate, oxygen saturation levels, and adverse events were evaluated. Results Pain during injection and treatment after administration of the warm local anesthesia (LA) technique was less as compared to the conventional block technique. Anesthetic success was observed with a faster onset of action (212.57 ± 32.51 s) and shorter duration of LA (165.16 ± 33.09 min) in the warm local technique as compared to the conventional technique. No significant differences were found with regard to heart rate and oxygen saturation levels between the two techniques. Administrating warm LA solutions at precooled injection sites revealed fewer adverse events. Conclusion Injecting warm LA solution on precooled injection sites causes less discomfort and anxiety in children, which makes it more suitable for the child as well as the pediatric dentist.
... Alternatively, cartridge warming devices may be used to achieve a recommended temperature for the warmed cartridge contents of 37°C to 43°C. 11,12 In an early double-blind crossover study by Davidson and Boom involving 25 subjects who received 1% lidocaine subcutaneously, 89% responded that the room temperature formulation (20°C) was more painful than the warmed anesthetic formulation at 37°C to 43°C. 7 A study by Lundbom et al involved 36 healthy volunteers who received three injections of 4.5 mL 1% lidocaine subcutaneously into the abdomen: one refrigerated at 8°C, one at room temperature at 21°C, and one warmed to 37°C. ...
... 14 In a split-mouth randomized clinical trial by Aravena et al in which 72 patients received either a warmed or room temperature injection of 0.9 mL of 2% lidocaine with 1:100,000 epinephrine in the buccal vestibule of the maxillary lateral incisal area, results showed that warmed local anesthetic resulted in significantly reduced pain compared to room temperature injections. 11 More recently, Gumus and Aydinbelge conducted a double-blind, split-mouth clinical study comparing the pain perception of room temperature (21°C) versus warmed (37°C) articaine in children aged 5 to 8 years. 15 One hundred subjects received a maxillary buccal infiltration, and the results showed a statistically significant reduction in pain perception and heart rate when the warmed local anesthetic was used. ...
Article
Full-text available
The importance of effective local anesthesia delivery in dentistry cannot be overstated, as many dental procedures could not be performed without it. Despite the availability to oral healthcare professionals of various successful local anesthetics, the administration of local anesthesia continues to provoke anxiety among dental patients and remains an often unpleasant experience. A number of techniques may be utilized to help mitigate injection pain and improve the patient experience. This article reviews four strategies clinicians may consider to increase the effectiveness of their delivery of local anesthesia: warming or cooling of local anesthetic solutions, vibration and distraction techniques, liposomal encapsulation, an buffering or alkalinization of dental local anesthetics.
... This effect enables the passage of anesthetic solution into the nociceptors, potentially contributing to pain reduction. 6 Buffered LA to a pH value closer to the physiological pH is another approach that has been proven to reduce the pain perception associated with the administration of LA and decrease the onset time. With an increase in the pH of the solution, more free bases will be available to cross the nerve sheath, thereby reducing the onset time. ...
... A study by Shin et al. 30) reported that the level of dental fear and worry is same as the level of pain and fear when people get a shot of anesthesia. Dentists should make an effort to ease dental patients' dental fear by actively considering the methods controlling pain, such as using local anesthesia on insertion site so that patients will not feel pain, injecting anesthetic fluids that are stored similar with the body temperature, injecting anesthetics slowly and constantly, and injecting anesthetics using painless anesthesia technique 31,32) . In this study, dental caries and anxiety are in the same classification (group 4). ...
... In conclusion, the use of skin compression on the upper lip during local maxillary anesthetic administration significantly reduced the perception of pain during the needle puncture and injection of the anesthetic compared to the use of conventional local maxillary anesthetic. Future studies will need to verify the effect of skin compression with this instrument on other anesthetic techniques and using other complementary methods for pain control such a warming anesthesic cartridges (28) in patients with acute dental pain. ...
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Objectives: To evaluate the effect of pressure on the skin of upper lip in decreasing pain perception during a local maxillary anesthetic injection. Material and Methods: A split-mouth crossover randomized clinical trial was designed. Seventy-one volunteer students (23.6±1.9 years old, 53.5% women) were selected. A group chosen at random had their left or right side of upper lip compressed by a wooden clothes peg as the compression instrument and 0.6 ml of lidocaine 2% with epinephrine 1:100,000 was administered at the buccal apex level of the lateral incisors tooth. Two weeks later anesthesia was administered on the opposite side of the lip according to the randomization recorded. The intensity of perceived pain level between the two injections using a 100 mm visual analog scale (VAS) and co-variable effect were compared (Wilcoxon test p < 0.05, RStudio). Results: The average of the perceived pain with and without upper lip compression was 27.6±14.5 mm (range 0-80 mm) and 36.33±17.9 mm (range 10-90 mm) respectively (p= 0.002). No significant differences were recorded according the covariance analysis with the sex (p = 0.55) and age (p = 0.89). Conclusion: The upper lip compression significantly reduces the perception of pain during a local maxillary anesthetic technique.
... temperature experienced different amount of pain during the application of injection i.e. 35.3 ± 16.71 at room temperature while 15 ± 14.67 at 42°C (107.6°F) with a p-value of <0.001. 4 Administering the local anesthetic at 42°C produces a lower pain intensity and shorter onset of action compared to doing so at room temperature. 5 The anxiety levels were reduced while using this method. ...
Article
Objective: To evaluate the effectiveness of using anesthesia at 42°C (107.6°F) for the insight of pain as dental sedative in contrast to its administration at room temperature 21°C throughout the procedure of maxillary infiltration. Study Design: Double-blind, Split-Mouth randomized clinical trial (Clinical trial number: ISRCTN79560957) Place and Duration of Study: Department of Armed Forces Institute of Dentistry, Rawalpindi, from Jan to Jun 2021. Methodology: A total of 38 patients were examined, undergoing maxillary premolar extractions for orthodontic purposes. Group- A received local anesthesia injection with the anesthesia warmed to 42°C (107.6°F) and group- B patients receiving local anesthesia injection with anesthesia at room temperature. The injection point was placed in the mucobuccal fold apically in the middle of maxillary premolars using a 27G short needle and injecting 0.9 mL of the anesthetics at the speed of 0.15 mL/second. Patients were instructed to grade intensity of pain on Visual analogue scale. Results: According to the Visual analogue scale score, the level of pain perceived with the anesthesia at 42°C (107.6°F) in group-1 was 3.81 ± 1.48 and the level of pain perceived with the anesthesia at temperature 21°C in group-2 was 5.57 ± 1.50 with statistically significant result (p=0.001). Conclusion: The use of anesthesia at 42°C (107.6°F) significantly reduced the pain during the injection of anesthesia compared to its use at room temperature during maxillary injections.
... Other measures are also on research to decrease the injection pain which can be achieved by changing the gauge and size of the needle tips, changing the type of analgesia, and changing the speed of distribution of this substance in dental tissues (Wang et al., 2014). On the other hand, the new techniques such as warming and buffering the analgesia (Aravena et al., 2018;Davoudi et al., 2016) and application of the novel computer-aided techniques for injection (Davoudi et al., 2016) were recommended for minimizing pain. In some cases, a local anesthetic gel is applied to reduce pain during insertion of the needle (Cho et al., 2017). ...
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Objectives: The present study aimed to determine the pain perceived during supraperiosteal (infiltration) injection in anterior maxillary region by Transcodent painless needle tips in comparison to the regular needle tips. Material and methods: In this split-mouth controlled randomised clinical trial, 30 patients were selected as candidates for cosmetic treatment who needed infiltration injections on both sides of canine area. They were each administered 0.9 mL of Lidocaine HCl 2% with epinephrine 1:100,000 in the buccal vestibules using two types of needle tips, Transcodent painless needle tip or regular needle tip. Immediately after the injection, the pain was measured using a 100 mm visual analog scale. The level of pain was statistically analyzed in the two groups using the parametric paired t-test. A 5% significance level was considered for statically significant difference between two means. Results: In accordance with the results, the patients' level of pain were estimated as 18.3 ± 10.7 mm with Transcodent painless needle tips and 43.1 ± 13.1 mm in regular needle tip (p < 0.05). Conclusion: The Transcodent painless needle showed considerable reduction of pain in the anterior maxillary infiltration when compared to the regular needle tips.
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Background: The efficacy of 2% lignocaine is reduced in a hot tooth. Local aesthetic agents can be preheated and buffered to increase their effectiveness. The present investigation was carried out due to limited information concerning adult patients with symptomatic irreversible pulpitis in mandibular teeth. Methods: A total of 252 individuals were included in the clinical trial in accordance with the selection criteria only after clinical study was registered with the Clinical Trial Registry of India (CTRI/2020/09/027796). Scores on the visual analog scale (VAS) and electric pulp test (EPT) on a 1-10 scale were recorded prior to the commencement of therapy. In this double-blinded study, patients were randomly divided by a co-investigator using computer randomisation (www.randomizer.org) into three groups, group A: inferior alveolar nerve blocks (IANB) with 2% lignocaine preheated at 42 °C (injected at 37 °C) (N = 84), group B: IANB of 2% lignocaine buffered with 0.18 ml of 8.4% sodium bicarbonate (N = 80) and group C: 2% lignocaine (N = 88). Excluding the dropouts of individuals (n = 11), wherein the anaesthesia failed, a total of 241 people were finally assessed 15 minutes after profound anaesthesia, endodontic access, and intraoperative pain were quantified using VAS. Pain on injection for all three groups was recorded immediately after IANB with VAS. The analysis was performed using one way ANOVA with Tukey's post hoc test and Paired T-Test using SPSS version 21. Results: Preheated, Buffered, and conventional 2% lignocaine showed statistically significant reduction in intraoperative pain (P < 0.001) compared to pre-operative but on inter-group comparison preheated and buffered showed highly significant pain reduction compared with conventional 2% lignocaine (P < 0.001). Conclusions: Warm and buffered local anaesthetic (LA) were effective in reducing intraoperative discomfort than conventional LA. Preheated local anesthetics caused the least pain, followed by buffered local anesthetics, while conventional local anesthetics caused the most pain.
Chapter
Mental health is a broad general term that consists of a person’s overall psychological, emotional, and social well-being. Our mental health is affected by our surroundings and the stressors the environment around us can place on us, our genetic makeup, past experiences, and chemical imbalances in our brains. Over the past few decades, there has been a growing awareness and acknowledgement of various mental health conditions within our society that can affect an individual’s functioning capacity. As the study of human behavior progresses, more mental health disorders are identified based on specific presentations which can help aid in identifying, treating, and preventing or minimizing the condition. Due to the extensive training in anesthesia, oral and maxillofacial surgeons often receive referrals from general dentists and specialist for the treatment of patients who require sedation for behavioral management. For perspective 20% of all adults and 17% of all children experience mental illness each year according to the national alliance on mental illness. This chapter aims to describe the most common behavioral health disorders that a patient may present within an oral and maxillofacial surgery office, focusing on the clinical presentation of these disorders, assessment of these patients to determine if they are candidates for office-based procedures, and their clinical management.
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Aim: To determine the effectiveness of anesthesia warming control pain feeling during the administration of anesthesia in maxillary infiltration technique nerve block. Methods: A double-blind clinical trial study was designed. Fifty-six volunteers students (mean age 23.1±2.71 years) of Universidad Austral de Chile Dental School (Valdivia, Chile) were participated. They were given 0.9 ml of 2% lidocaine with 1: 100,000 epinephrine (Alphacaine®; Nova DFL - Brazil) by two punctions at buccal vestibule of lateral incisor. In a hemi-arch a warm anesthesia of 42ºC (107.6°F) was administered; and after one week in to contralateral side a room temperature (21ºC; 69.8°F) was administered. In both times with a standard speed. The level of intensity pain perceived during injection was registered and compared by visual analog scale (VAS) of 100mm (Wilcoxon test p
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Background: The relatively membrane-impermeable lidocaine derivative QX-314 has been reported to permeate the ion channels transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential cation channel, subfamily A, member 1 (TRPA1) to induce a selective inhibition of sensory neurons. This approach is effective in rodents, but it also seems to be associated with neurotoxicity. The authors examined whether the human isoforms of TRPV1 and TRPA1 allow intracellular entry of QX-314 to mediate sodium channel inhibition and cytotoxicity. Methods: Human embryonic kidney 293 (HEK-293) cells expressing wild-type or mutant human (h) TRPV1 or TRPA1 constructs as well as the sodium channel Nav1.7 were investigated by means of patch clamp and ratiometric calcium imaging. Cytotoxicity was examined by flow cytometry. Results: Activation of hTRPA1 by carvacrol and hTRPV1 by capsaicin produced a QX-314-independent reduction of sodium current amplitudes. However, permeation of QX-314 through hTRPV1 or hTRPA1 was evident by a concentration-dependent, use-dependent inhibition of Nav1.7 activated at 10 Hz. Five and 30 mM QX-314 activated hTRPV1 via mechanisms involving the intracellular vanilloid-binding domain and hTRPA1 via unknown mechanisms independent of intracellular cysteins. Expression of hTRPV1, but not hTRPA1, was associated with a QX-314-induced cytotoxicity (viable cells 48 ± 5% after 30 mM QX-314) that was ameliorated by the TRPV1 antagonist 4-(3-chloro-2-pyridinyl)-N-[4-(1,1-dimethylethyl)phenyl]-1-piperazinecarboxamide (viable cells 81 ± 5%). Conclusions: The study data demonstrate that QX-314 directly activates and permeates the human isoforms of TRPV1 and TRPA1 to induce inhibition of sodium channels, but also a TRPV1-dependent cytotoxicity. These results warrant further validation of this approach in more intact preparations and may be valuable for the development of this concept into clinical practice.
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The aim of this study was to evaluate differences in pain scores with different visual analog scale (VAS) presentations and to compare those differences with a numeric rating scale. We also asked the patients for preference of the different methods. Prior to the trial, we performed power calculations to estimate a preferred sample size, and 62 postoperative patients supplied a complete set of data to the study. Inclusion criteria were newly operated patients within the first 5 days after surgery. Every patient included was with 1-minute intervals and presented with one of the following 100-mm VAS lines: VAS horizontal with or without stop lines at the endings, or VAS vertical with or without stop lines. They also completed a numeric rating scale (NRS). We did not find differences in pain scores between the four VAS measures. The NRS had slightly higher pain scores than VAS, especially at low levels of pain. Patients preferred the NRS as compared to the VAS, and when choosing between the four different VAS presentations, they preferred the horizontal VAS with stop lines at the ends. For daily clinical practice for guiding postoperative analgesic treatment, the NRS seems to be a good option measuring pain reliably with good patient understanding and acceptance. For pain research, where there may be more time to explain the method and when a scale with more data points may be preferred, a VAS horizontal including stop lines at the ends can be recommended. © 2015 World Institute of Pain.
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Local anesthetics are commonly utilized in the practice of dermatology. Minimizing local anesthetic injection pain can be beneficial to both physicians and patients. Easily implemented techniques that reduce injection pain of intralesional local anesthetics are reviewed.
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Injectable drug products are ideally developed as isotonic solutions. Often, hypertonic injectables may have to be marketed for a variety of reasons such as product solubilization and stabilization. A key concern during product formulation development is the local and systemic tolerability of hypertonic products upon injection. This report reviews and discusses the tolerability in terms of local discomfort, irritation, sensation of heat and pain, along with other observed side effects of hypertonicity in both in-vitro systems and in-vivo animal and human models. These side effects clearly depend on the degree of hypertonicity. The sensation of pain among different injection routes seems to follow this order intramuscular > subcutaneous > intravenous or intravascular. It is recommended that the upper osmolality limit should be generally controlled under 600 mOsm/kg for drug products intended for intramuscular or subcutaneous injection. For drug products intended for intravenous or intravascular injection, the recommended upper limit should be generally controlled under 1000 mOsm/kg for small-volume injections (≤ 100mL) and 500 mOsm/kg for large-volume injections (> 100mL). Several options are available for minimization of hypertonicity-induced pain upon product administration. Copyright © 2015. Published by Elsevier B.V.
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Purpose: To assess the levels of dental anxiety among patients anticipating dental treatments in dental clinics/hospitals of Ranga Reddy district. Materials and methods: A cross-sectional study was conducted among a representative sample of 1200 subjects (at least 18 years old) in dental clinics/hospitals which were selected from a list obtained through systematic random sampling. The data were collected using a pre-tested and calibrated questionnaire consisting of the Modified Corah Dental Anxiety Scale (MDAS) to assess anxiety levels. Results: The majority (52.4%) of subjects showed a low level of anxiety. Females (11.44 ± 4.41) were found to have higher mean MDAS scores than males, and the highest mean MDAS scores were found among 18- to 34-year-olds (11.28 ± 4.67) (P < 0.05). Significant differences were found among subjects anticipating different treatments, with higher MDAS scores for extraction (11.25 ± 5.4), followed by examination, root canal treatment, gum surgery, scaling, restoration and others, e.g. orthodontic treatment, restoration with crowns, bridges and dentures (7.79 ± 3.80). The highest mean MDAS scores were found among subjects who were apprehensive due to 'past difficult experience in dental treatments', followed by 'drill' and 'injection', with the lowest scores among subjects indicating 'other reasons' (7.82 ± 3.84). Conclusion: The present data show that anxiety levels are higher in patients who have to undergo extractions than those who must be fitted with dentures. Thus, dental health care providers should pay more attention to patients' anxiety levels associated with different types of treatment.