Dentine hypersensitivity – Australian dentists’ perspective
Dr Najith Amarasena
Australian Research Centre for Population Oral Health
School of Dentistry
The University of Adelaide
Adelaide SA 5005
Background: Dentine hypersensitivity is a frequent clinical presentation though inadequately comprehended by dentists. The objective of this study was to describe Australian dentists’ perception on the occurrence, predisposing factors, triggers, diagnosis and management of dentine hypersensitivity.
Methods: Eight hundred dentists were randomly selected using the Australian Dental Association membership list and invited to participate in a questionnaire-based survey.
Results: Out of 295 responding dentists, 284 private practitioners were included in the final analysis. Most dentists perceived that the occurrence of dentine hypersensitivity was <20% and commonest among 30–49 year olds. According to them, abrasion and gingival recession were the main predisposing factors whilst cold stimuli were the commonest trigger. A differential diagnosis-based approach was adopted by a majority to diagnose dentine hypersensitivity although routine screening was resorted to by a few. Most dentists were aware of the current mechanisms underlying dentine hypersensitivity whereas the majority perceived that ongoing predisposing factors was the main reason for dentine tubules to remain exposed. The commonest management strategy employed by most dentists was to prescribe desensitizing agents for home use.
Conclusions: Australian dentists’ perception of dentine hypersensitivity is generally consistent with the current scientific consensus on this subject.
Dentine hypersensitivity is defined as a distinctive short sharp pain arising from exposed dentine, characteristically in response to an array of stimuli including thermal, tactile, evaporative, osmotic or chemical, which cannot be attributed to any other form of dental defect, disease or pathology.1,2 There has been a growing body of research carried out on the aetiology and epidemiology as well as management of dentine hypersensitivity, pointing not only to widespread occurrence of this problem but also to the somewhat ambiguous nature of it.3–6 Accordingly, dentine hypersensitivity can be regarded as a clinical entity, which has not been clearly understood by dentists despite the high prevalence of this condition and extensive availability of non-invasive treatment for its management.1,6,7 A review by Walters5 suggests that dentine hypersensitivity affects well over 40 million people in the US and up to 30% of adults at sometime during their lifespan.
Indeed, a wide variation in the prevalence of dentine hypersensitivity ranging from 1.1% to 98% has been reported, which could be mainly ascribed to differences in the methodology as well as population settings among studies.3–6,8–25 For instance, the prevalence was greater in patients referred to specialist periodontology clinics and hospital clinics11,12,20,24 than in general practice patient populations.19,21,24 Likewise, a higher prevalence of dentine hypersensitivity has been observed when the assessment was based on questionnaires rather than on clinical tests.14,15,24 Virtually 50% or more of adults have complained of dentine hypersensitivity in studies based on patients’ perception of this problem,13,17 whereas according to dentists’ perspective, the prevalence of dentine hypersensitivity has ranged from 10% to 25%.16,23 As for the local scenario, it was reported that the prevalence of self-reported hypersensitive teeth in Australia was 13%18 whilst the proportion of patients with dentinal hypersensitivity that was expressed as a main diagnosis by Australian dentists had been reduced from 1.6% in 1993–1994 to 1.1% in 2003–2004.10
Even though numerous studies have been conducted on this topic, a bulk of them has focused on a specifically targeted group of general practices, which in turn, might have biased the findings.4,21 Accordingly, there is a clear need to explore the nature of dentine hypersensitivity in a randomly selected sample of general practices. Such an investigation would no doubt enhance the understanding of this problem amongst the dental practitioners and consequently benefit patients to maintain better oral health. The present study was, thus, conducted with the aims of describing the occurrence, predisposing and triggering factors as well as the diagnosis and management of dentine hypersensitivity as perceived by a randomly selected sample of private dental practitioners in Australia.
Materials and methods
Ethical approval for the study was granted by The University of Adelaide Human Research Ethics Committee. The Australian Dental Association (ADA) membership list was used as the sampling frame to randomly select 800 general dental practitioners who were invited to take part in this mailed questionnaire study. One dentist who was subsequently found to be working overseas was excluded, reducing the final target group to 799 dentists.
The questionnaire was designed based on worldwide reports about dentine hypersensitivity including its prevalence, the important predisposing factors, major triggers, mechanisms, differential diagnosis, patient management, dentist management and continuing education about dentine hypersensitivity. The questionnaire comprised three sections – A, B and C. Section A was designed to elicit the demographic characteristics of dentists including age, gender, country of birth, school and year of graduation, work status, practice type and location, whilst Section B focused on dentists’ perspective of patients presenting with dentine hypersensitivity and its causes, triggers and predisposing factors as well as diagnosis and management. Section C was a log recorded by dentists about the total number of patients seen including a detailed description of patients with dentine hypersensitivity such as age and gender of the patient, teeth and surfaces affected, symptoms reported, predisposing factors, triggers and management of dentine hypersensitivity during a typical week in practice.
The data were collected over a period of one year from October 2006 to October 2007. It involved two approaches including the initial package and four subsequent reminders, which were sent roughly 6–8 weeks apart. It was endeavoured through these reminders to maximize the response rate of dentists by taking certain measures such as enclosing a flow chart for easy completion of the questionnaire, a letter of endorsement and encouragement from the ADA and a gift voucher as a monetary incentive. Data were entered, transformed and analysed by employing SPSS 15.0 for Windows.
Out of 799 dentists who were finally invited to participate in the study, 295 had completed and returned the questionnaires to the investigators and thus, the unadjusted response rate was 36.9%. The adjusted response rate, after excluding the dentists who had returned the questionnaires indicating that they were no longer involved in general practice was 41.5%. Further 11 dentists who were mainly engaged in public sector (08), specialized/restricted practice (02) and tertiary education (01) were excluded to confine the final analysis to 284 private dental practitioners (respondents). Table 1 compares the demographic characteristics of respondents with those of Australian dentist population. Apparently, the responding dentists were comparable to the population of Australian dentists in relation to most of the characteristics. Age of the responding dentists ranged from 23 to 75 years with a mean of 44.5 years (sd = 11.3). Out of the 284 respondents, 73.2% were males and 26.8% were females. The proportion of Australian born dentists was 53.2% whilst those who were born overseas accounted for 46.8% of the sample. There were 71.1% of respondents graduated from Australian universities in comparison to 28.9% overseas graduates. The year of graduation of the dentists ranged from 1952 to 2005. Approximately 77% of the dentists were involved in full-time practice and the remaining 23% were part-timers.
Table 1. Demographic characteristics of the respondents and Australian dentist population
|Country of birth|
| Australia||151||53.2||N/A#|| |
| Overseas||133||46.8|| || |
| Australia||202||71.1||N/A#|| |
| Overseas||82||28.9|| || |
| 1950–1969||26||9.2||N/A#|| |
| 1970–1989||151||53.2|| || |
| 1990–2005||107||37.6|| || |
| Full-time ||218||76.7||7220||74.6|
Table 2 describes the occurrence of dentine hypersensitivity in relation to the number, percentage and age of the patients with dentine hypersensitivity as perceived by the dentists in their practices. Most dentists perceived that they saw less than 10 patients per week with dentine hypersensitivity, representing less than 20% of their weekly patient load. The symptoms of dentine hypersensitivity were perceived to be commonest among 30–49 year olds, whereas patients younger than 20 years were perceived to be the least affected.
Table 2. Dentists’ estimation of the occurrence of dentine hypersensitivity by the number, percentage and age of patients with dentine hypersensitivity
|No. of patients|
|% of patients|
|Age of patients|
It is apparent from Table 3 that abrasion was viewed as the most important predisposing factor for dentine hypersensitivity (74.7%), while gingival recession (67.3%), erosion (59.2%), attrition (31.4%), tooth whitening (27.8%), periodontal surgery (23.7%), plaque accumulation (17.3%) and restorative treatment (15.4%) were the other predisposing factors in the order of their perceived importance. Cold stimuli were the most frequently cited (67.5%) trigger of dentine hypersensitivity followed by air (39.4%), acid (13.7%), touch (13.0%) and hot (6.2%) stimuli.
Table 3. Dentists’ perception of the importance of predisposing factors and relevance of triggers of dentine hypersensitivity
| Gingival recession||67.3||25.6||6.0||1.1||0.0|
| Tooth whitening||27.8||42.6||20.2||7.9||1.4|
| Periodontal surgery||23.7||42.7||29.9||2.6||1.1|
| Plaque accumulation||17.3||36.0||28.4||14.7||3.6|
| Restorative treatment||15.4||34.1||32.6||15.4||2.6|
| Cold stimuli||67.5||28.9||2.9||0.7||0.0|
| Air stimuli||39.4||47.0||12.5||1.1||0.0|
| Acid stimuli||13.7||38.8||39.2||6.5||1.8|
| Touch stimuli||13.0||37.8||35.9||13.0||0.4|
| Hot stimuli||6.2||20.4||51.5||21.2||0.7|
Table 4 shows the different diagnoses considered by dentists when a patient complains of tooth sensitivity and the dentists’ perceptions of screening for symptoms of dentine hypersensitivity. Differentially diagnosed dentine hypersensitivity was most frequently considered in patients who presented with symptoms of tooth sensitivity (85%). Other differential diagnoses that were frequently considered included dental caries (79.7%), gingival recession (77.9%), cracked tooth (74.1%), pulpitis (65.2%), fractured restoration (55.0%) and fractured tooth (55.0%). Two-thirds of the dentists responded that they would very often screen for dentine hypersensitivity if symptoms were present. The percentage of dentists very often screening for dentine hypersensitivity was lower (33.9%) if signs for dentine hypersensitivity were present, but was much lower (16.0%) for screening as a routine measure. Nearly 6% of the dentists responded that they would not very often screen for dentine hypersensitivity.
Table 4. Dentists’ perception of differential diagnosis of tooth sensitivity and screening for dentine hypersensitivity
| Dentine hypersensitivity||39.6||45.3||14.0||0.7||0.4|
| Dental caries||30.6||49.1||19.2||0.7||0.4|
| Gingival recession||30.0||47.9||21.1||0.7||0.4|
| Cracked tooth||27.3||46.8||25.2||0.7||0.3|
| Fractured restoration||15.4||39.6||38.2||6.4||0.4|
| Fractured tooth||15.8||39.2||38.5||6.1||0.4|
| Screen if complain||66.2||29.5||3.6||0.7||0.0|
| Screen if signs present||33.9||42.8||18.1||4.1||1.1|
| Screen routinely||16.0||28.0||24.7||23.6||7.6|
| Do not screen||6.4||10.4||22.5||32.1||28.5|
As described in Table 5, most dentists (80.5%) considered that fluid flow within dentine tubules was the most plausible mechanism of dentine hypersensitivity. A further small percentage of dentists considered that stimulation of odontoblastic process was the main mechanism. Ongoing predisposing factors were most frequently cited (62.8%) as the main reason for dentine tubules remaining exposed in patients suffering from dentine hypersensitivity. A lower percentage of dentists believed that the continued presence of triggers, lack of effective self-care and lack of professional care were the main reasons for dentine tubules remained exposed.
Table 5. Dentists’ perception of mechanism of pain from dentine hypersensitivity and main reason for dentine tubules remain exposed
|Mechanism of pain|
| Fluid flow within dentine tubules causing nerve stimulation||223||80.5|
| Stimulation of the odontoblastic process via exposed dentine||50||18.1|
| Stimulation of pulpal nerves||02||0.7|
| Stimulation of cold receptors in the dental pulp||02||0.7|
|Main reason for dentine tubules remain exposed|
| Ongoing predisposing factors||177||62.8|
| Continued presence of triggers||50||17.7|
| Lack of effective self-care||33||11.7|
| Lack of professional care||22||7.8|
With regard to the strategies used in the management of dentine hypersensitivity, most dentists preferred to prescribe desensitizing agents for home use (Table 6). Other frequently employed management strategies in their order of the preference were modifying predisposing factors, restoring the surfaces, applying fluoride varnish and glass ionomer cements as well as unfilled resin. While nearly three-quarters of the respondents were of the opinion that the outcome of dentine hypersensitivity management would bring a degree of relief to the patient, a much lower percentage of respondents were optimistic that the outcome would be either long-lasting relief or an immediate relief to the patient. Interestingly, some 6.1% of the dentists observed continuation of symptoms in patients more often than not, irrespective of the management of dentine hypersensitivity, whereas nearly 4% of them were very often uncertain of appropriate management strategies.
Table 6. Dentists’ perception of dentine hypersensitivity management strategy and outcome
| Desensitizing agents for home use||52.7||36.7||10.0||0.6||0.0|
| Modify predisposing factors||55.3||34.5||7.4||1.8||1.1|
| Restoring the surfaces||8.7||34.2||46.9||7.3||2.9|
| Applying F varnish||18.9||30.9||29.5||13.1||7.6|
| Applying GIC||8.8||25.6||39.2||17.6||8.8|
| Applying unfilled resin||6.7||21.5||35.2||24.8||11.9|
| Other desensitizing agents||20.6||19.1||11.8||4.4||44.1|
| Applying strontium chloride||3.5||8.5||16.3||22.5||49.2|
| Endodontic treatment||0.4||1.5||25.5||38.4||34.3|
| Fluoride iontophoresis||0.8||4.7||11.3||9.8||73.4|
| Periodontal surgery||0.0||2.2||7.5||31.0||59.3|
| Laser treatment||0.0||0.8||4.2||2.3||92.7|
| A degree of relief||23.9||48.6||25.7||1.8||0.0|
| Long-lasting relief||14.9||45.9||36.3||2.8||0.0|
| Immediate relief||14.6||43.8||37.4||4.3||0.0|
| Continued symptoms||0.0||6.1||61.1||31.1||1.8|
| Unsure of appropriate management strategies||0.0||3.9||30.0||41.2||24.9|
Table 7 shows the dentists’ perception about the active ingredient and pain relieving mechanism of desensitizing toothpastes. Stannous fluoride (64.1%) and potassium nitrate (64.0%) were almost equally considered important active ingredients, while sodium fluoride (57.0%), strontium chloride (51.3%) and sodium monofluorophosphate (47.8%) were the other active ingredients cited by them in the order of importance. When questioned about the main mechanism of action for desensitizing toothpaste, most dentists (89.5%) were of the opinion that the main mechanism was blocking opened tubules, whereas remineralization of exposed dentine (74.3%), plaque removal (52.2%), disruption of pain transmission (45.3%) and strengthening of tooth structure (42.6%) were the alternative mechanisms considered.
Table 7. Dentists’ perception of desensitizing toothpastes by active ingredient and underlying mechanism of action
| Stannous fluoride||64.1||35.9|
| Potassium nitrate||64.0||36.0|
| Sodium fluoride||57.0||43.0|
| Sodium monofluorophosphate||47.8||52.2|
| Strontium chloride||51.3||48.7|
| Block opened tubules||89.5||10.5|
| Remineralize exposed dentine||74.3||25.7|
| Remove plaque||52.2||47.8|
| Disrupt pain transmission||45.3||54.7|
| Strengthen tooth structure ||42.6||57.4|
The current analysis was confined to Sections A and B of the questionnaire. Considering the usefulness as well as significance of information gathered from Section C and the extensive nature of such an analysis, it was decided to discuss the findings of Section C of the questionnaire in a separate publication. The findings showed that the age and gender distribution of the responding dentists is comparable to that of Australian Dental Labour Force26 and, therefore, this sample can be considered representative of the Australian dentist population on the whole. Given the measures employed to maximize the participation of dentists in the present study, a response rate of 41.5% could be considered low compared to some questionnaire-based surveys on dentists’ perceptions of dentine hypersensitivity where a response rate of 64.7% was yielded.23 However, our response rate is on par with that of Gillam et al.25 who reported a response rate of 44.9% in a selective group of UK dentists to a mailed questionnaire on dentine hypersensitivity, while being superior to others where a response rate as low as 7% was achieved.1 Nevertheless, a relatively high rate of non-response in questionnaire-based studies on dentine hypersensitivity could be ascribed in particular to the limited understanding of this condition by dentists and the uncertainty surrounding it23,25 and, in general to factors including lack of time and modest priority given by general practitioners to mailed questionnaires.27
Most private dental practitioners perceived that they encounter less than 10 patients with dentine hypersensitivity during a typical practice week and that the overall occurrence of dentine hypersensitivity among the patients was below 20%. This is in accord with the findings of many studies where the prevalence of dentine hypersensitivity was ranging from 13% to 18%14,15,18 but is low compared to the findings of Chabanski et al.,11,12 Irwin and McCusker,17 Rees et al.,22 and Taani and Awartani24 who reported high prevalence rates of over 50%. Such discrepancies could be mainly attributed to the methodology adopted: studies like this, based on general practice populations, yielded relatively lower prevalence rates19–21,24 in comparison to those focused on specialized and hospital clinics.11,12,22 Besides, investigations based on patients’ perspective of dentine hypersensitivity rather than that of dentists’ reported higher prevalence rates.13,17 The perception of the dentists that the presentation of symptoms of dentine hypersensitivity was peaking at 30–49 years and decreasing thereafter is virtually similar to the findings of several workers.15–17 Even though the elderly may be presented with more exposed dentine accompanied by gingival recession, age-induced changes such as secondary dentine formation and sclerosis of tubules can reduce the sensitivity of their teeth.4,6,8,15 The perspective of the present sample of Australian dentists further corroborates this view.
It was apparent that the majority of Australian dentists were aware of the importance of predisposing factors like abrasion, gingival recession, erosion and attrition as well as the relevance of triggers including cold, air and acid stimuli in the aetiology of dentine hypersensitivity. This is in agreement with the perceptions of the dentists from different countries.23,25 However, a substantial proportion of the responding dentists (53.3%) cited plaque accumulation as one of the important predisposing factors although dentine hypersensitivity has been shown to be associated with sites with low plaque accumulation whilst plaque-induced dentine sensitivity has been considered by some as an entirely different clinical entity from dentine hypersensitivity.8 Nevertheless, the role of plaque on the aetiology of dentine hypersensitivity remains ambiguous given that some studies have reported patients with poor plaque control to be more affected with dentine hypersensitivity.4 It was evident that most of the dentists in the present study considered the importance of differential diagnosis in excluding other possible causes of tooth sensitivity from dentine hypersensitivity, whereas a relatively lower proportion of them used routine screening for dentine hypersensitivity. Whilst differential diagnosis constitutes an essential part of dentine hypersensitivity management, screening is considered critical for the establishment of dentine hypersensitivity diagnosis.1,4,6 Apparently, four-fifths of dentists were aware of the fact that hydrodynamic theory is the currently accepted mechanism of pain from dentine hypersensitivity and also that ongoing predisposing factors as well as continued presence of triggers are the main reasons for dentine tubules remained open, all of which are in line with the current consensus.1,4,6
The commonest dentine hypersensitivity management strategy that was adhered to by almost 90% of the sample was prescribing desensitizing agents for home use and/or modifying predisposing factors, which is a greater proportion compared to the findings of Canadian survey, where only 50% of the responding dentists and hygienists had attempted such a strategy.1 It was also noteworthy that very few Australian dentists had resorted to invasive management strategies like periodontal surgery and endodontic treatment. It has been recommended that the first line of treatment of dentine hypersensitivity should be removal/modification of causes and/or predisposing factors of dentine hypersensitivity coupled with daily use of desensitizing toothpastes.1,4,6 Accordingly, the perspective of most dentists reflects this recommendation. It was also interesting to note that nearly 4% of the responding dentists were often uncertain of appropriate management strategies of dentine hypersensitivity, although this proportion was lower in comparison to 50% of Canadian respondents, who were reported to be lacking confidence in managing dentine hypersensitivity.1
Only 64% of the sample perceived the importance of potassium nitrate as an active ingredient in desensitizing toothpastes despite the worldwide availability of potassium nitrate containing desensitizing toothpastes,1,6 whereas a substantial proportion of them valued the importance of fluoride compounds as active ingredients. These views of Australian dentists are somewhat similar to those of their Canadian counterparts.1 Moreover, just 45% of the present sample considered disruption of pain transmission as an important mechanism of action of desensitizing toothpastes even though pain transmission disruption mediated by depolarizing activity of potassium ions has been regarded as one of the more acceptable mechanisms of action.1,4 On the contrary, 90% of the current sample of dentists believed that occlusion of opened tubules is one of the important mechanisms of desensitizing toothpastes, which is in accord with the view of Canadian dentists and hygienists.1 Interestingly, almost 84% of the dentists valued the importance of maintaining a patient information pamphlet on dentine hypersensitivity in their practice as opposed to the very few who were not in favour of this view (results not shown).
In conclusion, the findings of the present study have revealed that the perception of the majority of Australian private dental practitioners on the prevalence and aetiology, as well as diagnosis and management of dentine hypersensitivity, is generally consistent with the current scientific consensus on dentine hypersensitivity. Notwithstanding the fact that the most Australian dentists seem to possess fairly up-to-date knowledge on most of the issues involving dentine hypersensitivity, it is recommended to conduct continuing education programmes on a regular basis to update dentists’ awareness of dentine hypersensitivity in line with the mounting body of research on this subject. As opined by most dentists, the importance of maintaining a patient information pamphlet on dentine hypersensitivity in the dental practice cannot be understated.
The authors wish to acknowledge the Australian general dental practitioners who took part in this study and the financial support provided by Colgate-Oral Care.