art-6-deRidder-1-2020

www.stomaeduj.com
                    ANESTHESIOLOGY
                    UNCLARITIES ABOUT ARTICAINE: EFFICACY AND THE
Review Articles
                    RISK OF PARESTHESIA
                    Nicolas de Ridder1a           , Constantinus Politis1b*
                    1
                        Department of Oral and Maxillo-Facial Surgery, Faculty of Medicine, Catholic University of Leuven, Leuven, Belgium

                    MD, Student in Master of Medicine; e-mail: nicolas.deridder@student.kuleuven.be; ORCIDiD: https://orcid.org/0000-0003-1826-8470
                    a

                    MD, DDS, MM, MHM, PhD, Professor and Head; e-mail: constantinus.politis@uzleuven.be; ORCIDiD: https://orcid.org/0000-0003-4772-9897
                    b




                    ABSTRACT                                                                                 https://doi.org/10.25241/stomaeduj.2020.7(1).art.6

                    Background Articaine is a very popular local anesthetic in dentistry. A lot of claims have been made about
                    articaine over the years, both positive and negative. Many clinicians claim articaine is superior to lidocaine.
                    However, since a study in 1995 claiming an increased risk of paresthesia, there has been debate about
                    whether this is true or not.
                    Objective To review the current literature to clarify the current ambiguities about the possible superior
                    efficacy and the alleged higher risk of paresthesia.
                    Data sources As a basis, a handbook on local anesthesia was read, as well as its references to the topics
                    of interest. Afterward, the literature was searched for publications about both the efficacy and the risk of
                    paresthesia from 1990 to 2019.
                    Study selection Articles about the efficacy with clear data and minimal risk of bias were selected. For
                    paresthesia, the original articles were selected as well as more recent reviews highlighting the flaws in the
                    first studies.
                    Data extraction Information about the efficacy and the possible superiority of articaine compared to
                    lidocaine was extracted. For paresthesia, the most important historical publications were reviewed and
                    more recent reviews were evaluated.
                    Data synthesis These data were synthesized in an overview consisting of two parts. First, the properties
                    of articaine were review and what was learned about the efficacy of articaine in relation to other local
                    anesthetics was discussed. Secondly, an overview of the history of paresthesia was given and the flaws and
                    unclarities were highlighted.

                    KEYWORDS
                    Articaine; Epinephrine; Efficacy; Paresthesia; Dentistry.

                    1. INTRODUCTION                                                                   (both good and bad). Some of the good claims
                                                                                                      include a supposedly better potency, faster onset of
                    Articaine is an amide dental local anesthetic,                                    anesthesia and a higher success rate. The bad claim
                    synthesized in 1969 in Germany. It was specifically                               is mainly an alleged increased risk of paresthesia.
                    developed for dental use and got its approval for                                 Some of these claims have been shown to be correct
                    clinical use in countries all over the world in the                               (like the success in buccal infiltration anesthesia
                    years to follow. It became increasingly popular                                   in the adult mandible). However, on a lot of other
                    and is now the second most used local anesthetic                                  claims or initial reports there is no scientific evidence
                    in dentistry. Annually, approximately 600,000,000                                 to prove them or the results are contradictory.
                    cartridges are manufactured [1]. In 2018 the market
                    share of articaine was 39,3% in the United States,                                2. MATERIALS AND METHODS
                    and as much as 97% in Germany [1,2]. However,
                    lidocaine still remains the golden standard for local                             As background information and the basis of this
                    anesthesia.Over the years, articaine has been the                                 review, Malamed’s Handbook of Local Anesthesia
                    subject of intense discussion and (anecdotal) claims                              (seventh edition) was read. Afterward, searches were

                                     OPEN ACCESS This is an Open Access article under the CC BY-NC 4.0 license.
                                     Peer-Reviewed Article
                        Citation: de Ridder N, Politis C. Unclarities about articaine: efficacy and the risk of paresthesia. Stoma Edu J. 2020;7(1):44-51.
                        Received: January 22, 2020; Revised: February 13, 2020; Accepted: February 20, 2020 ; Published: February 22, 2020
                        *Corresponding author: Professor Constantinus Politis, MD, DDS, MM, MHM, PhD, Head, Department of Oral and Maxillo-Facial Surgery, Faculty of
                        Medicine, Catholic University of Leuven, Kapucijnenvoer 33, BE-3000, Leuven, Belgium
                        Tel: / Fax: 0032 (0)16332462
                        e-mail: constantinus.politis@uzleuven.be
                        Copyright: © 2020 the Editorial Council for the Stomatology Edu Journal.




    44              Stoma Edu J. 2020;7(1):44-51                                                                           pISSN 2360-2406; eISSN 2502-0285
Articaine: Efficacy and the risk of paresthesia
                                                                                                                         www.stomaeduj.com



made       on    PubMed, Trip         database     and     have a maximum recommended dose of 504 mg.




                                                                                                                       Review Articles
Limo with different combinations of the                    This equals 7 cartridges. These maximum dosages
following keywords: safety, clinical charac-               are well above the dosages normally needed in
teristics, paresthesia, efficacy, lidocaine, articaine,    routine dental care (normally a maximum of about
local anesthetics, epinephrine. A selection was made       three to four cartridges are needed during routine
of the most relevant articles to make this narrative       dental care). With six cartridges you could achieve
review.                                                    anesthesia of a full adult mouth [1]. Nevertheless,
                                                           exceeding the maximum recommended dose is the
3. CLINICAL CHARACTERISTICS                                most frequent cause of overdose reactions in dental
                                                           patients [1]. That is why it is important to always
Articaine hydrochloride (or 4-methyl-3-[2-(propylamino)    calculate this maximum dosage. If used within this
propionamido]-2-hiophenecarboxylic acid methyl             range, articaine is a safe drug to use. However, in
ester) is used in dental cartridges of 1.8 mL. These       some cases (like certain cardiac patients) a dose
cartridges contain 72 mg of articaine and 0.09 to 0.18     restriction could be advisable to maximize safety,
mg of epinephrine, depending on the concentration          as discussed in another review. There are also other
(1:200,000 and 1:100,000 respectively) [1].                important things to remember to safely use dental
                                                           local anesthetics and prevent overdose reactions.
3.1. Articaine                                             Basic injection techniques should be applied when
Although it is classified as an amide anesthetic,          administering local anesthetics to minimize the
articaine is considered a unique entity within the         chance of an overdose reaction. Careful aspiration
amide local anesthetics. It has different properties       should be performed prior to every injection to
compared to the other local anesthetics. Most              avoid accidental intravascular injection [1]. Further-
importantly, it contains an ester-linkage that can be      more, one of the most important factors for over-
hydrolyzed by plasma-esterases and turns articaine         dose appears to be the rate of injection: ideally a
in an inactive compound: articainic acid [2]. This rapid   cartridge is administered over a period of more than
manner of inactivation is the same biotransformation       60 seconds. A rapid injection (less than 15 seconds)
that occurs in the elimination of ester anesthetics [1].   results in significantly elevated blood levels when
This contributes greatly to the low systemic toxicity      accidentally administered intravenously, facilitating
of the drug. This mechanism also gives articaine           an overdose reaction [1].
its relatively short elimination half-life of only 27
minutes (compared to 90 minutes for lidocaine) [2].        3.2. Epinephrine
Secondly, it contains an aromatic thiophene ring           Epinephrine is added to the anesthetic solution as a
which would ensure greater lipid solubility. This          vasoconstrictor. This has several benefits: First of all,
would increase potency because articaine is better         it elicits vasoconstriction in the blood vessels, which
in penetrating tissue and bone [3]. Finally, articaine     does not only delay the absorption of the local
has a high degree of protein binding (95%). This           anesthetic and thereby decreasing systemic toxicity,
high degree of protein binding may account for a           but it also gives hemostasis, less per operative blood
longer duration of anesthetic effect as well for the       loss and better visibility. Secondly, it increases the
increased tendency to bind to the protein receptor         depth as well as the duration of action of anesthesia,
[1]. Clinically, the drug works by binding reversibly to   prolonging and enhancing the anesthetic effect.
the alfa-unit of the voltage-gated sodium channels         Because of this, the dose of anesthetic used can
in the nerve, thereby preventing the propagation           be reduced [1]. The addition of epinephrine does
of action potentials [3]. This gives pulpal anesthesia     have its implications: because of its effects on the
for approximately 60 minutes and soft tissue anes-         myocardium and the vascular tone, a dose restriction
thesia for 3 to 5 hours, making articaine an inter-        to a maximum of 40 µg per appointment as stated
mediate-acting anesthetic [4]. There is a theory           by Bennett and Malamed [2,6]. This equals four
suggesting that local saturation of serum esterases        cartridges of epinephrine 1:200,000. The safe
would cause a delay in local metabolism of articaine.      use of ≤ 4 cartridges of the higher concentrated
This mechanism would account for the prolonged             anesthetic lidocaine (1:100,000 epinephrine) was
anesthetic effect while the systemic toxicity remains      recently confirmed in a systematic review [7]. A
low [4]. A study showing high alveolar blood levels        lot of the other contra-indications or possible
of articaine post-extraction with an increased             interactions in the package leaflet of articaine are
metabolic rate from articaine to articainic acid           included because of the addition of epinephrine as
supports these claims [5]. As with all drugs, the          well. It should be noted however that the doses of
clinician should be careful not to elicit overdose         epinephrine used in dentistry are minimal. One 1.8
reactions by using too much of the drug. Articaine         mL of 1:100,000 and 1:200,000 epinephrine contains
has a maximum recommended dose of 7.0 mg/                  0.018 and 0.009 mg respectively. This dose is rather
kg [1]. A cartridge contains 1.8 mL of anesthetic          low compared to other uses of epinephrine in
solution, so for articaine 4% it equals 72 mg of           medicine (0.3 to 1 mg in case of anaphylactic shock)
articaine. A normal healthy adult of 72 kg would           [1]. In these small quantities, the systemic cardio-



Stoma Edu J. 2020;7(1): 44-51                                             pISSN 2360-2406; eISSN 2502-0285                45
                    de Ridder N. et al.
www.stomaeduj.com

Review Articles      Table 1. Successful pulpal anesthesia.                                             Table 2. Onset time of pulpal anesthesia.

                                                  Articaine         Lidocaine          P-value                                 Articaine            Lidocaine
                                                                                                                               onset ±SD            onset ±SD            P-value
                          Mandibular                                                                                             (min)                (min)
                                                     75%                45%             0.0001
                         second molar
                                                                                                          Mandibular
                        Mandibular first                                                                   second               4.6 ± 4.0           11.1 ± 9.50           0.0001
                                                     87%                57%             0.0001
                           molar                                                                            molar
                         Mandibular                                                                       Mandibular
                                                     92%                67%             0.0001                                  4.2 ± 3.1             7.7 ± 4.3           0.0002
                       second premolar                                                                    first molar
                        Mandibular first                                                                  Mandibular
                                                     86%                61%             0.0001
                          premolar                                                                          second              4.3 ± 2.3             6.9 ± 6.6           0.0014
                                                                                                           premolar
                    Robertson D, Nusstein J, Reader A, Beck M, McCartney M. The anesthetic
                    efficacy of articaine in buccal infiltration of mandibular posterior teeth. J Am      Mandibular
                                                                                                             first              4.7 ± 2.4             6.3 ± 3.1           0.0137
                    Dent Assoc. 2007;138:1104–1112, Table 1                                                premolar

                                                                                                       Robertson D, Nusstein J, Reader A, Beck M, McCartney M. The anesthetic
                                                                                                       efficacy of articaine in buccal infiltration of mandibular posterior teeth. J Am
                                                                                                       Dent Assoc. 2007;138:1104–1112, Table 2

                    vascular effects are modest to negligible depending                                As is turns out, articaine gives the best improvement
                    on the type of patient [1]. Of course, it should                                   in success rate comparing to lidocaine (55,6% to
                    be mentioned that in some cases it is not safe to                                  91,7% for the first molar, 66,7% to 88,9% for the
                    use articaine (like some refractory unstable heart                                 second molar) [10].
                    diseases) [1]. However, these are all contraindications
                    to general elective dental care as well and need                                   4.2. Conclusion
                    immediate attention from a medical specialist.                                     A meta-analysis by Katyal in 2010 comparing arti-
                                                                                                       caine with lidocaine concluded that articaine has a
                    4. EFFICACY                                                                        higher anesthetic success in the posterior first molar
                                                                                                       area, while the safety is comparable with lidocaine
                    There are some reports of clinicians who state that ‘in                            (RR 1.31, 95% CI of 1.12 to 1.54) [11]. However, the
                    their opinion’ articaine has a faster onset following                              variability of anesthetic success of certain techniques
                    injection. However, in a study comparing the time of                               and the effect of local inflammation were not taken
                    onset of pulpal anesthesia after an inferior alveolar                              into account [4,11]. Yapp provided a comprehensive
                    nerve block (IANB) between 2% lidocaine and 4%                                     overview of seventeen papers comparing the efficacy
                    articaine in 1554 patients, these claims were not                                  of articaine [4]. Ten papers found no significant
                    supported [2].                                                                     difference, while 7 papers did find an advantage
                    It has also been claimed that articaine may provide                                for articaine (however each review investigated
                    palatal anesthesia when given as maxillary buccal                                  different clinical situations) [4]. As a conclusion, the
                    infiltration [1]. Although this claim is anecdotal, it                             overall efficacy of articaine is similar to lidocaine. For
                    could be attributed to the greater lipid solubility.                               mandibular infiltrations, mental nerve blocks and a
                                                                                                       buccal infiltration following an IANB, articaine does
                     4.1. Mandibular infiltration                                                      appear to have a significant advantage [4]. Paxton
                    A claim that has been shown to be true is the                                      and Thome reviewed all 27 publications until 2010
                    significant success of articaine used by buccal                                    reporting on the efficacy of articaine [12]. These
                    infiltration in the mandible.                                                      publications showed a variability of outcomes,
                    When articaine was used for mandibular infiltration                                but nevertheless their meta-analysis did show a
                    in adults, it has been proven that the chances of                                  significant difference (9.21% higher proportion of
                    success are significantly greater in comparison to                                 success, 95% CI 2.56% to 15.58%) [2]. This suggested
                    lidocaine (see Table 1) [8].                                                       an advantage for articaine, at least in some clini-
                    The time of onset for pulpal anesthesia was also                                   cal situations [13]. Furthermore, articaine was com-
                    significantly shorter for articaine in the first and                               pared with 1:100,000 and 1:200,000 epinephrine
                    second molar, and the first premolar (see Table 2) [8].                            concentrations and no significant difference was
                    Another study found similar results concerning                                     found [12]. However, it should be noted that all these
                    the mandibular incisor: Both the duration and the                                  studies are only low to moderate-quality evidence
                    success rate of pulpal anesthesia was considerably                                 so conclusions must be critically reviewed.
                    longer with the articaine solution [9].
                    The reason for this increased success rate could be                                5. PARESTHESIA
                    the relatively thin cortical plate, subject to the potent
                    penetrating capability of articaine [2].                                           Local anesthetics are used to achieve anesthesia in
                    Kanaa et al. did research on the addition of articaine                             the desired area to perform a pain-free procedure.
                    or lidocaine infiltration to improve the success rate                              Normally this anesthesia wears off in a matter of
                    of anesthesia following an IANB [10].                                              hours, but there have been reports of paresthesia



    46              Stoma Edu J. 2020;7(1):44-51                                                                             pISSN 2360-2406; eISSN 2502-0285
Articaine: Efficacy and the risk of paresthesia
                                                                                                                                                              www.stomaeduj.com




                                                                                                                                                            Review Articles
Table 3. Risk of paresthesia from local anesthetic drugs.                         Table 4. Relative risks of paresthesia in Ontario, Canada and the
                                                                                 United States.
                        2007           2012                 Result
                                                                                                             Ontario, Canada              United States
                                                       <1.0, less than
    Lidocaine            0.64           0.5                                          Mepivacaine                1 : 1,250,000             1 : 623,112,900
                                                         expected
                                                                                       Lidocaine                1 : 1,125,000             1 : 181,076,673
     Articaine           1.19          0.97            ~1, expected
                                                                                     Bupivacaine                      NA                  1 : 123,286,050
                                                     >1.5, higher than                Overall risk               1 : 785,000               1 : 13,800,970
  Mepivacaine             NA            2.2              expected                      Articaine                 1 : 440,000                1 : 4,159,848
                                                     >3.0, higher than                 Prilocaine                1 : 588,000                1 : 2,070,678
    Prilocaine           4.96          3.25              expected                Malamed SF. Articaine 30 years later. Oral Health. 2016; Table 8
The ratio derived from the percentage of reported cases of paresthesia divided
the percent market share of the drug.
Malamed SF. Articaine 30 years later. Oral Health. 2016; Table 9

There have been studies reporting a higher incidence                             in Denmark, that a local anesthetic, articaine, was
of paresthesia with the use of 4% local anesthetics                              responsible for an increased risk of nerve injuries
like prilocaine and articaine. An overview of the                                compared with the risk associated with other local
history of this controversy is given below.                                      anesthetics (mepivacaine, prilocaine, lidocaine)”
                                                                                 [15]. The report concluded: “Regarding articaine,
5.1. History                                                                     the conclusion is that [the] safety profile of the drug
Everything started with a retrospective study by Haas                            has not significantly evolved since its initial launch
and Lennon in 1995 [13]. They examined voluntary                                 (1999 in Denmark). Thus, no medical evidence exists
submissions that dentists made to their insurance                                to prohibit the use of articaine according to the
agency. They found 143 cases of paresthesia over                                 current guidelines listed in the summary of product
a 20-year period (1973 to 1993), excluding those                                 characteristics” [15]. “All local anesthetics may cause
associated with surgery [13]. The paresthesia involved                           nerve injury (they are neurotoxins). The occurrence
the lingual nerve, the inferior alveolar nerve or a                              of sensory impairment is apparently slightly more
combination of both [13]. Based on the distribution                              frequent following use of articaine and prilocaine.
of the market share of local anesthetics in Ontario in                           However, considering the number of patients treated,
1993, articaine and prilocaine had a relatively higher                           sensory impairments rarely occur. For example, the
risk of developing paresthesia [13]. In 1993, 10 of the                          incidence of sensory impairment following the use
14 reports of paresthesia were related to articaine,                             of articaine is estimated to be 1 case in 4.6 million
the other 4 to prilocaine. This equals an overall                                treated patients” [2,15]. Furthermore, they reported
risk of 1:785,000. The individual rates reported for                             that there are different incidents that can result in a
articaine (1:588,235) and prilocaine (1:440,529)                                 nerve injury: mechanical injury due to needle trauma,
were a lot higher than the other anesthetics                                     direct drug toxicity or neural ischemia for example
(1:1,250,000) [13]. Almost all of the forthcoming                                [15]. The Danish Medicines Agency followed up
papers claiming an increased risk of paresthesia                                 with this study in October 2011 (117/43) [16]. Their
refer to this paper as the original source. Hillerup                             database of side effects comprised 160 reports of
and Jensen conducted a study (2006) reviewing                                    adverse reactions related to articaine between 2001-
insurance claims in Denmark, where articaine was                                 2005, most of which concerning nerve damage [16].
introduced in 2001 [14]. They claimed that articaine                             However, since 2005 they have observed a drop
had a higher tendency to cause paresthesia as it was                             in the number of new adverse reaction reports.
most reported to the Danish Medicines Agency by                                  For 2011, up until the first of October they only
dentists [14]. They declared that articaine should                               received 2 reports of possible sensory impairment
not be the anesthetic of choice when administering                               [16]. This drop in the number of adverse effects can
an IANB until factual information is available, a                                be explained by two phenomena: the Weber Effect
statement consequentially recommended by the                                     and the effect of publicity on drug prescription and
Danish Dental Association as well [14]. In this                                  usage [2]. Both phenomena will be clarified later.
review, 77% of the cases reviewed involved only the                              Pogrel also wrote some interesting papers about
lingual nerve, and not the inferior alveolar nerve                               articaine over the years [17–21]. In a 2007 paper,
[14]. In response, the Pharmacovigilance Working                                 Pogrel investigated 57 nonsurgical cases of
Committee of the European Union reviewed arti-                                   paresthesia following local anesthetic administration
caine use in 57 different countries addressing the                               from 2003 to 2005 [16,17]. His update on this paper
controversy about paresthesia [15]. They estimated                               in 2012 reported on an additional 41 cases from
the number of patients receiving articaine is around                             2006 to 2011 [18]. In both reviews, Pogrel compared
100 million annually [15]. In October 2006 they                                  the percentage of the market share of the local
published the following report: “This investigation                              anesthetic to the proportion of the incidences of
is a follow-up to an inquiry initiated in 2005. This                             paresthesia reports [17,18]. Articaine had a ratio of
enquiry resulted from suspicions that were raised                                1.19 in 2007 and 0.98 in 2012 [17,18]. Lidocaine did



Stoma Edu J. 2020;7(1): 44-51                                                                          pISSN 2360-2406; eISSN 2502-0285                        47
                    de Ridder N. et al.
www.stomaeduj.com

Review Articles      Table 5. Reports of paresthesia following local anesthesia with the most
                    common local anesthetics.
                                                                                                         Table 6. Lingual nerve involvement in reported cases of paresthesia.


                                                       Cases of                                                                                                       Lingual
                                                                                  All ADRs
                                                      paresthesia                                                                                                      Nerve
                                                                                                              Authors               Country            Year        Involvement
                      Lidocaine                             247                     7,720                                                                               (%)
                      Bupivacaine                            99                     2,843                    Haas and                Canada            1995                70.6
                      Articaine                              85                      254                     Lennon14
                      Combinations of                                                                      Hillerup and             Denmark            2006                77.0
                                                             45                     2,687                    Jensen15
                      local anesthesia
                                                                                                                           24
                      Prilocaine                             30                      396                  Garisto et al.         United States         2010                92.7
                                                                                                                           23
                      Other                                  67                     4,647                 Kingon et al.             Australia          2011                80.0
                      Total                                 573                    18,574               Malamed SF. Articaine 30 years later. Oral Health. 2016; Table 8
                    ADR: Adverse drug reactions
                    Piccinni C, Gissi DB, Gabusi A, Montebugnoli L, Poluzzi E. Paraesthesia after Lo-
                    cal Anaesthetics: An Analysis of Reports to the FDA Adverse Event Reporting
                    System. Basic and Clinical Pharmacology and Toxicology. 2015; Table 2

                    better than expected an only had a ratio of 0.64 in                                 about the studies performed. What is the rationale
                    2007 and 0.5 in 2012 [18]. The results are shown in                                 behind the fact that the vast majority of paresthesias
                    table 3 (see Table 3) [2,17,18]. Following these results,                           occurs after an IANB? Less than 5% of the cases
                    Pogrel concluded that there is no disproportionate                                  involve the maxilla, while roughly half of the dental
                    nerve involvement for articaine [22]. Prilocaine,                                   work is in the maxilla [2]. Why are these cases of
                    however, does show a higher incidence (ratio 4.96                                   paresthesia rather specific to the use of an IANB
                    and 2.2 in 2007 and 2012 respectively) [22]. One of                                 and not with alternative nerve blocks (like Gow-
                    the points of criticism noted in this paper is that in the                          Gates) [2]. Why are there no similar reported toxicity
                    reports to outside agencies there is no mentioning                                  cases with articaine use in the other branches of
                    whether the paresthesia was transient or permanent                                  medicine (plastic surgery, dermatology, …) [3].
                    (as most of the paresthesias eventually recover) [23].                              Some elements concerning the hypothesis of the
                    The Australian regulatory body issued a warning                                     neurotoxicity as the cause of the cases of paresthesia
                    statement against articaine as well following a                                     remain unexplained. As seen in the previous papers
                    2011 paper by Kingon discussing 5 case reports of                                   the vast majority of cases of paresthesia involved
                    paresthesia following local anesthetic administration                               the lingual nerve, in the Garisto paper even 89%
                    [22]. However, in 2 of these cases, the only thing the                              involved exclusively the lingual nerve (see Table 6)
                    patient experienced was an ‘electric shock’ with                                    [2,13,14,22,23]. If neurotoxicity caused paresthesia
                    the injection [22]. Garisto conducted research in                                   we would expect the inferior alveolar nerve to
                    the United States in July 2010 with data gathered                                   be involved much more commonly. Opening the
                    from the US Food and Drug Administration (FDA)                                      mouth to deposit the cartridge could stretch out the
                    Adverse Event Reporting System (AERS) between                                       lingual nerve, preventing it from being pushed away
                    1997 and 2008 [23]. From the 248 cases, of which                                    by the needle and being damaged [2]. In another
                    94.5% happened as a result of an IANB, there was as                                 paper, he explained this discrepancy could be
                    much as 89% that exclusively involved the lingual                                   partially explained by the fact that the lingual nerve
                    nerve [23]. Of these 248 cases, 108 resolved in a                                   only consists of one to three fascicles, while the IAN
                    time period between 1 to 736 days [23]. In this study                               consists of five to seven fascicles [21]. The claim of
                    Garisto compared the incidences with the paper of                                   a possible higher intrinsic toxicity of articaine 4%
                    Haas and Lennon (1995): It appears the difference in                                compared to lidocaine 2%, which could possibly
                    incidence is more than a tenfold (see Table 4) [13,24].                             explain a higher incidence of paresthesia, was not
                    It is noteworthy that the FDA website for AERS warns                                supported in in-vitro investigations [26]. While some
                    that the AERS data has limitations: Reports do not                                  remain believing in the intrinsic higher neurotoxicity
                    require to prove a causal relationship, reports do not                              of the 4% anesthetics, others believe there are factors
                    always contain enough detail and not all adverse                                    usually involved to cause the paresthesia (primarily
                    events are reported [24]. Therefore, they state that                                mechanical trauma) [1]. There are a lot of different
                    AERS cannot be used to calculate incidences for the                                 ways nerve paresthesia could be explained: Trauma
                    US population [24]. Another study analyzed the data                                 by contact of the nerve sheath with the needle,
                    of the AERS in the United States from 2005-2011. 573                                hemorrhage into or around the neural sheath as the
                    cases of paresthesia were identified out of the 18,574                              pressure on the nerve will increase, edema following
                    reports [25]. Table 5 gives an overview of the reports                              surgical procedures[1]. Keep in mind that one does
                    for the most common anesthetics (see Table 5).                                      not exclude the other. Next, focus will be on the
                                                                                                        Weber Effect and the effect of publicity. The Weber
                    5.2. Unclarities                                                                    Effect is an epidemiological event that constitutes a
                    There are numerous comments or thoughts to be                                       rise in reporting of adverse events after its regulatory
                    made about the controversy about paresthesia and                                    approval, with a peak at the end of its second year



    48              Stoma Edu J. 2020;7(1):44-51                                                                                pISSN 2360-2406; eISSN 2502-0285
Articaine: Efficacy and the risk of paresthesia
                                                                                                                                           www.stomaeduj.com



                                                                           advantages in comparison to other local anesthetics,




                                                                                                                                         Review Articles
                                                                           there is no conclusive evidence demonstrating
                                                                           neurotoxicity or significantly superior anesthetic
                                                                           properties of articaine for dental procedures” [4].
                                                                           Van der Sleen evaluated 1000 patients receiving an
                                                                           IANB, and concluded that no long-term injury will
                                                                           be caused as long as the mandibular nerve is not
                                                                           manipulated [29]. When applying a local anesthetic
                                                                           would result in paresthesia, these are only temporary
                                                                           and the cause remains unknown [29]. The most
                                                                           common cause of nerve injury remains mechanical
                                                                           trauma like surgery or third molar extractions.
                                                                           Malamed makes the following recommendation:
 Figure 1. Articaine use and reports of paresthesia (Denmark).             For the administration of an IANB you can continue
Malamed SF. Handbook of Local Anesthesia. 7th ed. St Louis: Mosby; 2019,   to use articaine 4% with epinephrine 1:100,000 or
Figure 20.9
                                                                           1:200,000, provided you use the correct injection
(see Fig. 1) [1,2]. Afterward, the reports steadily                        techniques [2]. If, however, the practitioner is not
decline while prescribing rates keep rising steadily                       convinced by the absence of scientific evidence
[2]. This is a replicable and verified phenomenon                          or still concerned, an alternative could be to use
[27]. Publicity (whether positive or negative)                             lidocaine 2% with epinephrine 1:100,000 followed
affects how much drugs are used and prescribed                             by infiltration anesthesia with articaine in the desired
[2]. Implemented on this debate, we conclude that                          area to improve effectiveness [2].
indeed the use of articaine decreased after the
paper of Hillerup and the recommendation of the                            6. DISCUSSION
Danish Dental Association [2]. After the EU report
explaining there was no significant evidence, the use                      In the early days of the drug, there were a lot of
increased again [2]. Another potential confounder                          anecdotal claims that articaine would function faster
might be the age of the dentist, as more numerous                          and better than other anesthetics. Different meta-
younger, inexperienced dentists use articaine as an                        analyses confirmed that the safety profile of articaine
anesthetic [26]. The last remark is the inconsistency                      is similar to that of lidocaine [9,10]. In certain clinical
of the reported risks on paresthesia. As already                           situations, articaine does have a significant advantage
mentioned, the variation between the reported risks                        over lidocaine (mainly for infiltration anesthesia in the
is tremendous, pleading there must be some kind                            posterior mandibula) [4,11,12]. However, there is no
of bias. In his 2000 paper, Pogrel estimated the risk                      convincing evidence to suggest that articaine has an
of permanent nerve damage following an IANB at                             overall superiority in efficacy over lidocaine. In 1995
1 in 26,762 injections [19]. Therefore, he stated that                     a retrospective study about paresthesia occurrence
a dentist would reasonably encounter at least one                          after the administration of local anesthetics started
case in their career [19]. For a risk of 1 in 785,000 as                   a controversial debate whether or not articaine
mentioned in the Ontario paper however, this would                         causes more paresthesias than lidocaine [11]. In the
mean a practitioner would encounter a paresthesia                          following years, numerous papers were published,
once every 436 years (averaging 1,800 injections                           and different recommendations were sent out by
every year) [28]. Another overall incidence reported                       different regulatory bodies. All these reports on
is 1:13,800,970 in the US [2]. To put these risks into                     the alleged higher incidence by articaine show
perspective: the risk of being struck by lightning in                      contradictory results, widely varying incidences, and
a given year in the US is between 1 in 328,000 and 1                       incomplete or biased data. Malamed, well-known in
in 700,000 [1].                                                            matters related to local anesthesia and a proponent
                                                                           of articaine, wrote an interesting overview of the
5.3. Conclusion                                                            subject [4,11,12]. Whether negative or positive,
The studies reporting an increased risk of                                 most of the time one single author is proclaiming
paresthesia contain a lot of bias: The total duration                      his/her own beliefs without high-quality clinical
of paresthesia, the injection technique, the size of                       evidence like a randomized controlled trial or a
the needle and even the anesthetic used (in 30%                            proper meta-analysis to back it up. Because of the
of the incidents reported) are examples of data                            rarity of the complication, an RCT would require
that are not always documented in these papers                             too large of a sample size. In 2006 the European
[28]. A 2011 review by Yapp highlights the flaws in                        Pharmacovigilance System concluded there was
studies concerning articaine: All studies reporting an                     no scientific or clinical evidence of a greater risk
increased risk contain bias in data recruitment and                        associated with articaine after examining all
are retrospective [4]. They are not suitable for a strong                  available clinical data from the Septodont database
recommendation [4]. He concluded that “although                            [2]. The Danish authorities confirmed these conclu-
there may be controversy regarding its safety and                          sions after reevaluation in 2012 [2]. Up until now,



Stoma Edu J. 2020;7(1): 44-51                                                              pISSN 2360-2406; eISSN 2502-0285                 49
                    de Ridder N. et al.
www.stomaeduj.com



                    there is no conclusive evidence that articaine would                     tor for paresthesia is still mechanical violation during
Review Articles
                    cause a larger number of paresthesias in proportion                      surgery or tooth extractions. The lingual nerve is
                    to its market share [2].                                                 most frequently affected rather than the inferior
                                                                                             alveolar nerve due to its anatomy. It should be
                    7. CONCLUSION                                                            kept in mind that a sensory disturbance after local
                                                                                             anesthetic use in non-surgical cases still remains an
                    Investigations on the superiority of articaine                           extremely rare event.
                    showed an advantage over lidocaine in certain situ-
                    ations (like infiltration anesthesia in the posterior                    CONFLICT OF INTEREST
                    mandible). There is insufficient evidence to state
                    that articaine has an overall superiority to lidocaine.                  The authors declare no conflict of interest.
                    Due to the lack of conclusive evidence, the choice
                    of local anesthetic should be purely based on the                        FUNDING
                    practitioner’s experience and personal preference.
                    Concerning the topic of paresthesia, there exists no                     This article did not require funding.
                    scientific evidence proving the alleged higher risk of
                    articaine on paresthesia. The available research on                      ACKNOWLEDGMENTS
                    the matter predominantly comprises the convictions
                    of one single author, whether positive or negative,                      This study was conducted as a master thesis to acquire the degree
                    without high-quality evidence. The main causal fac-                      of master in medicine at the Catholic University of Leuven.




                    REFERENCES
                    1. Malamed SF. Handbook of local anesthesia . Seventh edition. St.       15. Stenver DI, Case number: 3200-1367, Adverse effects from
                    Louis, MO: Elsevier Inc; 2020.                                           anaesthetics used in relation with dental care with a special focus
                    2. Malamed SF. Articaine 30 years later. Oral Health. [Internet] 2016.   on anaesthetics containing articaine. Pharmacovigilance Working
                    [Full text links]                                                        Party of the European Union. 20 October, 2006.
                    3.Snoeck M. Articaine: a review of its use for local and regional        16. Danish Medicines Agency (Laegemiddel Styrelsen), Report 25
                    anesthesia. Local Reg Anesth. 2012;5:23-33.                              October 2011.
                    [Full text links] [CrossRef ] [PubMed] Google Scholar Scopus             17. Pogrel MA. Permanent nerve damage from inferior alveolar
                    4.Yapp KE, Hopcraft MS, Parashos P. Articaine: a review of the           nerve blocks - an update to include articaine. J Calif Dent Assoc.
                    literature. Br Dent J. 2011;210(7):323-329.                              2007;35(4):271-273.
                    [Full text link] [CrossRef ] [PubMed] Google Scholar                     [Full text link] [PubMed] Google Scholar Scopus
                    5.Oertel R, Richter K, Weile K, et al. A simple method for the           18. Pogrel MA. Permanent nerve damage from inferior alveolar nerve
                    determination of articaine and its metabolite articainic acid in         blocks: a current update. J Calif Dent Assoc. 2012;40(10):795-797.
                    dentistry: Application to a comparison of articaine and lidocaine        [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
                    concentrations in alveolus blood. Methods Find Exp Clin Pharmacol.       19. Pogrel MA, Thamby S. Permanent nerve involvement resulting
                    1993;15(8):541-547.                                                      from inferior alveolar nerve blocks [published correction
                    [PubMed] Google Scholar Scopus                                           appears in J Am Dent Assoc. 2000;131(10):1418]. J Am Dent Assoc.
                    6. Bennett CR. Monheim’s local anesthesia and pain control in dental     2000;131(7):901-907.
                    practice, 7th edition. St. Louis, MO: CV Mosby; 1984.                    [Full text link] [PubMed] Google Scholar Scopus
                    7. Godzieba A, Smektała T, Jędrzejewski M, Sporniak-Tutak K. Clinical    20. Pogrel MA, Thamby S. The etiology of altered sensation in the
                    assessment of the safe use local anaesthesia with vasoconstrictor        inferior alveolar, lingual, and mental nerves as a result of dental
                    agents in cardiovascular compromised patients: a systematic              treatment. J Calif Dent Assoc. 1999;27(7):531-538. [PubMed]
                    review. Med Sci Monit. 2014;20:393-398. doi: 10.12659/MSM.889984         Google Scholar Scopus
                    [Full text links] [PubMed] Google Scholar Scopus                         21. Pogrel MA, Schmidt BL, Sambajon V, Jordan RCK. Lingual
                    8. Robertson D, Nusstein J, Reader A, et al. The anesthetic efficacy     nerve damage due to inferior alveolar nerve blocks: a
                    of articaine in buccal infiltration of mandibular posterior teeth. J     possible explanation. J Am Dent Assoc. 2003;134(2):195-199.
                    Am Dent Assoc. 2007 Aug;138(8):1104-1112;                                [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
                    [Full text link] [PubMed] Google Scholar Scopus                          22. Kingon A, Sambrook P, Goss A. Higher concentration local
                    9. Meechan JG, Ledvinka JIM. Pulpal anaesthesia for mandibular           anaesthetics causing prolonged anaesthesia. Do they? A literature
                    central incisor teeth: A comparison of infiltration and                  review and case reports. Aust Dent J. 2011;56(4):348-351.
                    intraligamentary injections. Int Endod J. 2002;35(7):629-634.            [Full text link] [CrossRef ] [PubMed] Google Scholar
                    [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus              23. Garisto GA, Gaffen AS, Lawrence HP, et al. Occurrence of
                    10. Kanaa MD, Whitworth JM, Corbett IP, Meechan JG. Articaine            paresthesia after dental local anesthetic administration in the
                    buccal infiltration enhances the effectiveness of lidocaine              United States [published correction appears in J Am Dent Assoc.
                    inferior alveolar nerve block. Int Endod J. 2009;42(3):238-246.          2010;141(8):944]. J Am Dent Assoc. 2010;141(7):836-844.
                    [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus              [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
                    11. Katyal V. The efficacy and safety of articaine versus lignocaine     24. U.S. Food and Drug Administration Center for Drug
                    in dental treatments: A meta-analysis. J Dent. 2010;38(4):307-317.       Evaluation and Research, Office of Post-Marketing Drug Risk
                    [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus              Assessment. Revised 9 January 2009. http://www.fda.gov/Drugs/
                    12. Paxton K, Thome DE. Efficacy of articaine formulations:              GuidanceComplianceRegulatoryInformation/Surveillance/
                    quantitative reviews. Dent Clin North Am. 2010;54(4):643-653.            AdverseDrugEffects/default.htm.
                    [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus              25. Piccinni C, Gissi DB, Gabusi A, et al. Paraesthesia after local
                    13. Haas DA, Lennon D. A 21 year retrospective study of reports of       anaesthetics: an analysis of reports to the FDA Adverse Event
                    paresthesia following local anesthetic administration. J Can Dent        Reporting System. Basic Clin Pharmacol Toxicol. 2015;117(1):52-56.
                    Assoc. 1995;61(4):319-330.                                               [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
                    [PubMed] Google Scholar Scopus                                           26. Hopman AJG, Baart JA, Brand HS. Articaine and
                    14. Hillerup S, Jensen R. Nerve injury caused by mandibular block        neurotoxicity - a review. Br Dent J. 2017;223(7):501-506.
                    analgesia. Int J Oral Maxillofac Surg. 2006;35(5):437-443.               [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
                    [Full text link] [CrossRef ] [PubMed] Google Scholar Scopus




    50              Stoma Edu J. 2020;7(1):44-51                                                                pISSN 2360-2406; eISSN 2502-0285
Articaine: Efficacy and the risk of paresthesia
                                                                                                                                   www.stomaeduj.com



27. Hartnell NR, Wilson JP. Replication of the Weber effect using     29. van der Sleen JM, Jaspers GW, de Lange J. Trigeminal




                                                                                                                                 Review Articles
postmarketing adverse event reports voluntarily submitted to the      nerve paraesthesia from inferior alveolar nerve blocks:
United States Food and Drug Administration. Pharmacotherapy.          incidence and course. Oral Surg. 2015;8(4):217-220.
2004;24(6):743–749.                                                   [Full text link] [CrossRef ] Google Scholar Scopus
[Full text link] [CrossRef ] [PubMed] Google Scholar Scopus
28. Diaz M. Is it safe to use Articaine? TeamWork. 2009;2(2):28-35.
doi: 10.14219/jada.archive.2001.0152
[Full text link] [PubMed] Google Scholar



                                                                                    Nicolas de RIDDER
                                                                         MD, Student in Master of Medicine
                                                                Department of Oral and Maxillo-Facial Surgery
                                                                                         Faculty of Medicine
                                                                               Catholic University of Leuven
                                                                                            Leuven, Belgium



CV
Nicolas De Ridder (DOB: 28th of May, 1996) obtained his bachelor’s degree in Medicine at the Catholic University of Leuven,
Belgium (magna cum laude). He is currently in his final year of master in Medicine, expected to graduate in July 2020. He has
acquired experience in internships in the department of Stomatology, Oral and Maxillofacial surgery under the supervision of
Professor Constantinus Politis at UZ Leuven.




Questions
1. What is the most common cause of overdose reactions or complications in dental
treatment with local anesthetics?
qa. Using an excessive total dose of the drug;
qb. Not complying with the listed contraindications;
qc. Use in children;
qd. Use in cardiovascular compromised patients.

2. What is true about the efficacy of articaine compared to lidocaine?
qa. Articaine is overall the superior local anesthetic;
qb. The efficacy of articaine is similar to that of lidocaine, with an advantage in certain clinical situations;
qc. Articaine is an inferior local anesthetic compared to lidocaine;
qd. Articaine is a better local anesthetic than lidocaine, but it is not worth the benefit because of its higher
risks.

3. Which of the following statements concerning the pharmacological properties about
articaine is not true?
qa. Articaine has a shorter elimintation half-life than most other local anesthetics;
qb. Articaine has a thiophene ring ensuring greater lipid solubility;
qc. Articaine contains an ester-linkage that can be hydrolyzed by plasma-esterase, making it a hybrid
molecule;
qd. Articaine has a low degree of protein-binding, just as most other local anesthetics.

4. The incidence of paresthesia for articaine is:
qa. Significantly lower than lidocaine;
qb. In relation to its market share;
qc. Higher than prilocaine;
qd. Higher than its market share.




Stoma Edu J. 2020;7(1): 44-51                                                        pISSN 2360-2406; eISSN 2502-0285               51