Dentists’ perceptions of a new local anaesthetic drug – articaine

Authors


Dr Kehn Yapp
Postgraduate Endodontics
Melbourne Dental School
The University of Melbourne
5th Floor, 720 Swanston StCarlton VIC 3053
Email: keyapp@hotmail.com

Abstract

Background:  Articaine is a new local anaesthetic drug introduced to the Australian dental market. The aim of this study was to elicit information regarding the use of articaine in Australia, and factors that influence attitudes towards adoption of new technology.

Methods:  A self-administered postal questionnaire was sent to a stratified systematic sample of dentists who were members of the Australian Dental Association, with questions regarding details about articaine use and how influences such as education and scientific literature affect their adoption of new technology.

Results:  Of the sample, 53% responded and over 70% of dentists surveyed used articaine, with 95% and 97% of respondents identifying scientific literature and continuing professional development courses respectively as influencing factors in their adoption of new technology. The most common reason for not using articaine was no perceived advantage and the most influential factor that would encourage non-users to start using articaine was a scientifically proven advantage. Senior clinicians, specialists and public sector dentists were less likely to use articaine.

Conclusions:  A majority of Australian dentists were using articaine and cited continuing professional development courses, scientific literature and anecdotal peer reports as being influential in their adoption of new technology.

Abbreviations and acronyms:
ADA

Australian Dental Association

CPD

continuing professional development

IANB

inferior alveolar nerve block

LA

local anaesthetic

Introduction

Articaine is a new local anaesthetic (LA) drug that was introduced to the Australian dental market in 2005. Although there are many anecdotal reports of its superiority over other LAs, the majority of the available literature indicates that in many clinical situations, articaine has comparable properties to other commercially available LAs.1 Controversy exists regarding its safety, with an early report suggesting a higher incidence of paraesthesia (persistent anaesthesia or an abnormal or unprovoked sensation) being associated with articaine use.2 However, the controversy regarding neurotoxicity has not been proven, with the only published randomized controlled trial specifically evaluating articaine’s safety showing it to be a safe drug to use in most areas of clinical dentistry.3

Dentistry is a quickly evolving profession with new techniques and products being constantly offered. Currently, there are little data on the way Australian dentists respond to or adopt a particular product and hence there is little information on how new technology impacts society. Because of this, appropriate mechanisms for introducing new technology into dentistry are currently unknown.

The aims of this study were to determine: (1) the current profile of articaine users in Australia; (2) their reasoning behind articaine use or non-use; and (3) the effect that different levels of education had on their decision-making process.

Methods

A self-administered postal questionnaire was sent to a stratified systematic sample of Australian Dental Association (ADA) members in July 2010. The minimum sample size was determined using a formula by Dillman,4 with the population size of 10 000 dentists and the proportion of the population expected to choose one of two response categories set at the most conservative level of 0.5. The degree of sampling error was set to 3% and confidence level set to 95%. The estimated effective sample size was n = 964. The sample was divided into metropolitan and rural groups for every state and territory using Australia Post classifications, except for the Australian Capital Territory (ACT), Northern Territory (NT) and Tasmania which had one group each, and stratified by the same proportion as that of current ADA members. Due to the small number of dentists from rural areas in South Australia, and the small overall numbers in the ACT, NT and Tasmania, these groups were oversampled in order to help provide a more representative sample. The questionnaire elicited sociodemographic data, information on current LA and articaine use, perceptions on new technology and factors influencing clinical decision making. A pilot study was sent to six general dentists and two specialists and modified accordingly. To allow for an estimated response rate of 60%, the total sample size was n = 1668.

Each participant was sent a one-page plain language statement (PLS), a three-page questionnaire and a reply paid return envelope. Two weeks after the initial mailout, the non-respondents were identified and sent a one-page reminder letter. Four weeks after the reminder letter was sent, a new PLS, questionnaire and reply paid return envelope was sent to the non-respondents. Questionnaires returned blank or marked return to sender were removed from the list.

The three-page questionnaire consisted of four parts containing questions eliciting information regarding sociodemographic data, education and technology, current LA use and articaine use. The education and technology section asked subjects how they felt towards certain statements on new technology, education, anecdotal reports and adopter categories using a modified four-point Likert scale (strongly disagree, disagree, agree, strongly agree). The LA and articaine use section asked questions regarding the reasons and situations behind use and non-use of articaine.

Data were entered into a Microsoft Excel spreadsheet and analysed using PASW Statistics Version 18 Software (SPSS Inc, IBM, IL, USA). The project was approved by The University of Melbourne Human Research Ethics Committee.

Results

A total of 819 usable responses were returned, with an additional 108 marked as blank or return to sender, giving an effective response rate of 53%. A majority of the survey population were male general dentists working in private practice who had completed their primary dental degree in Australia (Table 1). Over half were working in metropolitan locations and approximately 70% were currently using articaine. Regarding adopter groups, only 11% considered themselves to be in the innovator/early adopter group, with 60% in the early majority group, and nearly 30% in the late majority/laggard group.

Table 1.   Sociodemographic details of sample (%)
 Age groupTotal (n = 819)
≤35 years (n = 211)36–45 (n = 186)46–55 (n = 222)56+ yrs (n = 200) 
Gender
 Male45.063.473.492.568.5
 Female55.036.626.67.531.5
Registered scope of practice
 General practitioner97.189.790.587.091.1
 Specialist2.910.39.513.08.9
Practice sector
 Private84.489.193.290.489.3
 Other15.610.96.89.610.7
Location of practice
 Urban58.265.055.747.256.5
 Rural41.835.044.352.843.5
Location of primary degree
 Australia80.573.584.779.079.7
 Overseas19.526.515.321.020.3
Adopter group
 Innovator/early adopter7.712.011.614.411.4
 Early majority64.758.760.256.260.0
 Late majority/laggard27.529.328.229.428.6

There were different usage patterns of articaine across a range of demographic and practice variables (Table 2). Articaine use was more common in younger dentists and those aged 46–55 years, general practitioners, those working in private practice, rural areas and those who identified as the early majority of adopters. Although the overall rate of usage was low for specialists, this ranged from 5% for orthodontists and 29% for paediatric dentists, to between 58% and 80% for oral and maxillofacial surgeons, periodontists, prosthodontists and endodontists. Nearly 30% of dentists who were not currently using articaine had previously used articaine, with the most common reasons given for not using articaine being no perceived advantage (47%) and toxicity concerns (19%). Furthermore, 17% of non-users were unaware of the existence of articaine, 16% indicated that it was unavailable to them and 4% did not use articaine because it was too expensive.

Table 2.   Details of articaine users (%)
 Users (n = 580)Non-users (n = 239)
  1. (a) Pearson Chi-square = 9.33, p = 0.025.

  2. (b) Pearson Chi-square = 19.43, p = <0.001.

  3. (c) Pearson Chi-square = 4.75, p = 0.029.

  4. (d) Pearson Chi-square = 10.67, p = 0.005.

Age group (a)
 ≤35 years75.424.6
 36–45 years68.831.2
 46–55 years74.825.2
 56+ years63.536.5
Gender
 Male71.728.3
 Female69.031.0
Registered scope of practice (b)
 General practitioner73.326.7
 Specialist48.651.4
Practice sector
 Private72.427.6
 Other62.837.2
Location of practice (c)
 Urban68.931.1
 Rural76.323.7
Location of primary degree
 Australia71.128.9
 Overseas69.330.7
Adopter group (d)
 Innovator/early adopter69.230.8
 Early majority75.524.5
 Late majority/laggard63.836.2

The most influential factor that would encourage non-users to start using articaine was a scientifically proven advantage (24%) followed by cost benefit (18%) and colleague influence (18%). A very high proportion of respondents (88%) used articaine because they believed it was more likely to achieve profound anaesthesia, 42% of users believed it had a faster onset and 12% used it only because a colleague suggested it to them. Nearly one-quarter of users used articaine routinely, with 34% using it for all procedures except for administering the inferior alveolar nerve block (IANB). For 24% of users, it was used when other anaesthetics did not achieve profound anaesthesia. Some 53% of all users used articaine for patients of all ages and 41% only used it for adults aged 18 and older, with a further 3% using it only for patients six years and older.

For those who indicated the way they first learned about articaine as an anaesthetic for clinical use, the most common method was from colleagues, then CPD courses. Product company representatives and scientific journals had a similar influence on the way users first found out about articaine (Fig. 1).

Figure 1.

 Methods of first finding out about articaine.

A total of 95% of respondents agreed that scientific literature influences the way they adopt new technology and 76% indicated that their adoption of new technology is influenced by colleagues’ anecdotal reports. However, 32% regarded anecdotal reports being more influential than scientific evidence. Over 30% were influenced by product company promotions or representatives, CPD influenced a majority of respondents (97%) and for the 64% who recognized that an opinion leader influenced their way of adopting new materials or technology, only 8% viewed CPD presenters as opinion leaders. A majority (87%) considered specialists and/or university academics as opinion leaders.

Logistic regression showed that general practitioners, rural and private practitioners were more likely to use articaine, whilst older dentists and those who identified in the late majority/laggard category were significantly less likely to use articaine (Table 3).

Table 3.   Logistic regression model for articaine use
 Exp (B)p
  1. Hosmer & Lemeshow Chi2 = 11.62, p = 0.169; Nagelkerke R2 = 0.077.

Age0.990.036
SpecialistRef 
General practitioner2.80<0.001
UrbanRef 
Rural1.440.050
Public practiceRef 
Private practice1.720.041
Adopter group
 Late majority/laggardRef 
 Early majority1.770.003
 Innovator/early adopter1.610.116
Primary degree AustraliaRef 
Primary degree overseas0.900.622

Discussion

The present study highlights several key themes regarding Australian dentists’ perceptions of articaine and factors that influence their clinical decision making. It also outlined differences between the adoption of articaine and the adoption of new technology. Whilst the response rate was lower than expected, the original sample size calculation was based on the most conservative level of half the population being expected to choose one of two response categories. When this was adjusted to match the actual proportion of articaine users (71.1%), the estimated effective sample size would become n = 806. Therefore, the study population of 825 responders may be considered a sufficient sample size. Furthermore, the sociodemographic profile of respondents mirrored the broader dentist population with regard to gender, scope and location of practice,5 indicating a low chance of non-response bias and the sample population is likely to be representative of the dental workforce in Australia.

Whilst scientific literature was reported to be integral in technology adoption, it was not a major influence in respondents’ ways of finding out about new technology. This may be due to many clinicians not having access to scientific journals or not having sufficient interest to seek current literature. Currently, there are no ongoing formal assessment protocols for registered dentists to maintain registration so there may be little value for some clinicians in actively seeking current information from scientific publications. It may explain the relatively high proportion of dentists (32%) who considered anecdotal peer reports as being more influential than scientific literature. In the emerging era of evidence-based dentistry, it appears that a substantial number of dentists may not base treatment decisions for their patients on the best available evidence.

Many of the reasons behind articaine use or non-use contradicted current findings in the scientific literature. For example, 88% of users believed articaine is more likely to achieve profound anaesthesia and 24% used it only when other LAs did not provide profound anaesthesia. Yet the literature shows articaine has comparable clinical properties to other available LAs in several clinical settings with no demonstrable advantage.1 One likely reason for this observation is that the advocacy of an apparent superiority of articaine has mainly been distributed through anecdotal reports in peer networks and that information exchange, depending on the communicated experience of others, is essential to behaviour exchange.6 A study on general dentists in New Zealand showed that colleague influence in new technology adoption was low, with no greater than 25% of respondents reporting colleagues being an influential factor on them having invested in a certain technology.7 Conversely, the present study showed that the most common way for finding out about articaine (39%) was from colleagues. It is clear that anecdotal reports have a role in the diffusion of technology in dentistry; however, its effectiveness and significance is an area that needs further research.

Approximately one-third of users reported using articaine for all procedures except the IANB. A possible explanation for this is that previous warnings on using articaine for IANBs were due to a suggested increased risk of paraesthesia when used in an IANB only.2,8–10 Similarly, non-users’ reasons for non-use of articaine included a perceived risk of toxicity. Whilst only few scientific reports give suggestion of this warning, it is likely that anecdotal reports of caution contribute to the patterns of articaine use in different clinical settings. However, this is an area that is currently unknown and requires further investigation. These risks have never been substantiated and are based on studies using voluntary, retrospective and biased data collection methods. There are alternative suggestions about the potential neurotoxicity of articaine being related to the available concentration (4%) instead of the drug administered, as similar associations have been reported with 4% prilocaine solutions.8,9 An animal study11 also reports a link between neurotoxicity and an increased articaine concentration but these reports do not take into account nor provide explanations for the clear evidence showing that the distribution of reported non-surgical paraesthesia involving 4% solutions almost exclusively involves nerves in the mandible, particularly the lingual nerve, and not in the maxilla. In addition to the theory of neurotoxicity, another suggested explanation for nerve injury is the interference with the vascularization of the nerve.12 Whilst the anatomy of the lingual nerve may contribute to the observation that it is most commonly involved in reports of paraesthesia,13 no experimental clinical study has specifically investigated why this is the case or why such an observation is not found in the maxilla. In particular, the structure and function of the lingual and inferior alveolar nerves in comparison to terminal branches of the maxillary division of the trigeminal nerve and the effect that different concentration LAs have on the individual nerves, is an area that requires further research. The only report of non-surgical paraesthesia in the maxilla involved 2% lignocaine and 3% mepivicaine,14 indicating an inconsistency with proposed theories of concentration-related paraesthesia as all nerves are not equally involved.

It is apparent that whilst many dentists indicated scientific literature influenced their adoption of technology, their responses did not reflect the available information. This is consistent with earlier studies indicating that predictors of the rate of adoption or innovation are based on whether the clinician perceives an advantage or disadvantage.15,16 The only reason consistent with the current literature was the most common reason for non-use, being no perceived advantage (47% of non-users).

Financial reasons did not appear to be a major influence in non-adoption with 4% of non-users not using articaine because it is too expensive and 18% citing that a cost benefit would encourage them to switch to using articaine. Currently, local anaesthetic agents are a relatively minor expense, with lignocaine and mepivacaine costing approximately $1.29 per 2.2 mL carpule and articaine being $1.59 per 2.2 mL carpule (personal communication, Henry Schein Halas, Australia, July 2011). A Brazilian report showed lignocaine had a significantly greater cost benefit than mepivacaine and articaine;17 however, the economic market in that study may differ to that of Australia and other countries.

Continuing professional development courses have been a way for dentists to keep up with current education and techniques. It provides an accessible method of learning and interaction with peers. Previous reports have shown that a majority of dentists had changed their clinical practices as a result of attending CPD programmes,18–20 which was also suggested in the present study. Whilst the majority of respondents (97%) agreed that CPD influenced their adoption of new technology, a low 8% of those who identified an opinion leader being influential in technology adoption indicated that CPD presenters were opinion leaders with approximately one-fifth of users first finding out about articaine at a CPD course. The inconsistency between the reported actions and respondents’ beliefs about CPD is reflective of that found in the attitudes toward scientific literature.

Conclusions

Articaine was used by a majority of Australian dentists, who cited scientific literature, CPD courses and product company representatives as influences in their adoption of new technology. Anecdotal reports throughout peer networks were common methods of diffusion of technological information. Many reported reasons concerning use and non-use of articaine were not based on current findings from scientific literature. Dentists’ perceptions of an advantage or disadvantage were more influential than scientific evidence in their adoption or non-adoption of technology.

Acknowledgements

The work in this paper was supported by the Australian Dental Research Foundation and the Australian Society of Endodontology. None of the authors have any financial or personal interest in any of the products mentioned in this article.

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