Community
Dent. Oral Epidemiol. 1978: 6'; 151-158
(Key words; dentures; (noslhetic hcahneni)
Supply and demand for prosthetic treatment in Victoria, Australia M.
H . SPRATLEY
Department Melbourne, . ._
.
of Dental Prosthetics, School of Dental Science, University of Melbourne, Australia .ABSTRACT - Surveys were conducted in Victoria, Australia, to estimate the demand for prosthetic treatment by examining the needs of a t-andomly selected gronp of the population. Similar surveys were conducted in relation to the contribution made by the dentists in Victoria and also that of a recently introduced group of workers, the Advanced Dental Technicians. It was found that approximately 19 % of the population required prosthetic treatment in the full denture field and that the existing dentists were not meeting this need. When the Advanced Dental Technicians are more fnlly engaged in clinical work, the need may well be met. (Accepted for publication 25 February 1978)
During the past 2 years a series of examinations was conducted by the Advanced Dental Technicians Qualifications Board (set up under the Dental Technicians Act, 1972; No. 8366, Victoria) at The Royal Dental Hospital of Melbourne, which resulted in over 120 Advanced Dental Technicians being licensed and allowed to deal directly with the public. Their service is limited to full dentures in already edentulous mouths free of pathology, plus -relines and repairs in similar situations. Obviously this will have some impact on organized dentistry in Victoria and therefore it was decided to survey the population to determine the demand and requirement for prosthetic services. In conjunction with this, two more postal surveys were to be conducted; one of all those Advanced Dental Technicians already licensed, a total of 122, and another of a random sample of 200 dentists taken from the Dental Register of Victoria, to attempt to determine the part they could play in satisfying this demand.
MATERIAL AND METHODS P O P U L A T I O N SURVEY Recent surveys on dental health in Australia by GILLINGS, DoDD, GRAHAM & BARNARD'^ and EVANS & CELEIER-'' were
of patients rather than of a sample of the popnlation as a whole and it was decided therefore that a sui-vey of a sample chosen from the electoral rolls for Victoria would meet the requirements of this study. A postal sun'ey was chosen in preferenee to face-to-face inter\'iews because it was felt that some of the questions may have been somewhat embarrassing to the respondents and that there may have been some reluctance to discuss inthnate details with a complete stranger. However, postal sui-veys have a notoriously low reply rate. A not dissimilar sui-vey carried out by DA^-ll•;s & W.XLSH^ in New Zealand had a reply rate of only 38.5 %. That suivey could be criticized in as much as the questionnaire was heavily loaded prosthetically, which could account for the very high percentage, 72.9 %, of the respondents wearing dentures. In a more recent survey (1968) in New Zealand carried out by BURGESS & BECK', the reply rate was improved to 66.4 % by use of publicity in the media. However, similar criticisrns could still be levelled at the design of the questionnaire. Consequently, a pilot suivey was carried out of 50 peo])le whose names were chosen at random from the Melbourne telephone directory. The pilot survey received a response rate in excess of 60 % in spite of the fact that a reminder letter was not used. The sample for the main survey was chosen from the electoral rolls for Victoria, which include most adults of 18 years and above. Although this excludes a large proportion of the population, it was felt that denture wearing among the younger age groups, although not uncommon, would represent a small percentage of the demand overall. Other disadvantages of the electoral rolls are that there are many
152
SPRATLEY
reeent migrants who are not listed and the rolls at any one time will never be completely up to date. A total sample of 500 was chosen, representing 0.022 "/o of the population on the electoral rolls. A |)redetermined number of names was chosen at random from each electorate in proportion to the relative size of that electorate. Each person chosen was sent a covering letter, questionnaire and stamped addressed envelope. Those not replying after 3 weeks were sent a second questionnaire with a further covering letter. After excluding those letters returned "address unknown" or "deceased", the response rate was in excess of 80 %. A variety of questions were a.sked iticluding respondent's age, sex, dental state, denture wearing history and demand for all forms of dental treatment. Questions were included concerning occupation and education to act as indicators of social class and also questions about locality. Questions concerning attitude towards the cost of dentistry were asked in order to increase interest in the survey, thus improving the reply rate. Care was taken to avoid the survey appearing to be loaded towards the denture wearers, i.e. questions were worded to encovirage those people not wearing dentures to reply. The results were processed by cotiiputer at LaTrobe University.
RESULTS POPULATION SURVEY Dental state - Respondents were asked how many of their own teeth they had and they were required to fit them.selves into one of three groups: "All or most", "some" and "none". These groups were considered as fully or near fully dentate, partially dentate and edentate, respeetively (Table 1). These figures are somewhat similar to those of surveys in other States in recent years. Demand for dental treatment — Respondents were asked if they thought they needed dental treatment at the time of reply and if so, what its nature was (Table 2). There was an overlap as some individuals demanded more than one form of treatment; although it would have been possible to separate this overlap using the computer, it has not
No. of respondents
Percent of total
Fully or near fully dentate Partially edentulous Fully edentulous
193
49
94 107
24 27
Total
394
100
Table 2. Demand for dental treatment No. of respondents
Percent of total
75
19 23 13 6
Demanded dentures Demanded "fillings" Demanded extractions Demanded "gum treatment"
88
51 23
beeti done for the pitrposes of this paper. A crosstabulation of dental state by demand for dentures showed that 14.7 % of those demanding dentures could be classified as fully or near fully dentate. A further 38.7 % were partially dentate and 46.7 % edentate. The first two groups, the fully and partially dentate, eould be demanding either partial or immediate dentures and there is no practical way of distinguishing them, but the third group, 9.1 % of the total respondents, must be demanding full dentures. Sex - Of the replies, 54 % were from males and 46 % from females, which is of some interest as females make up approximately 52 % of the population on the electoral rolls. A cross-tabulation of detital state by sex (Table 3) shows that the pereentages of males and females elassified as fully or near fully dentate are similar, while a smaller pereentage of females could be elassified as partially edentate with the larger percentage edentate; this may be explained in part by age discrepancies, females having a longer life expeetaney and representing a larger proportion of the older age group than the males. A cross-tabulation of sex against demand shows that of the respondents deniandini> dentures, 48.6 %> were male and 51.4 % female.
Table 3. Cross-tabulation of dental state by sex (54 % of respondents were male eompared with only 48 % of the ]5opulation) Malerespondents " (%)
Female respondents n (%)
Fully or near fully dentate Partially edentulous Fully edentulous
105 (49.5%)
88 (48.9%)
57 (26.9%) 50 (23.6%)
37 (20.6%) 55 (30.6%)
Total
2!2
180
Dcmnnd for proslhetic treatment
153
T a b l e 4. Cross-tabulation of locality against demand for dentures No. of respondents from locality
Percent of total res])ond.
No. of respond. demanding dentures
Percent of respond. from locality
263
67.6
47
18.1
Large country town ( > 3,000 pop.)
74
19.0
15
20.5
Small country town ( < 3,000 pop.) or remote area
52
13.4
12
23.1
Locality Melbourne metropolitan area
74
389
Total
T h i s difference is not statistically significant. Howe v e r if (-lie slightly poorer response from females is t a k e n into consideration, it may indicate that more f e m a l e s than males are actually demanding dentures. Locality — Over two-thirds of the respondents -were living in the Melbourne metropolitan area. Comparison with figures from the Victorian Year Book'"' indicate that the reply rate was not biased tov^ards town or country. When locality was crosstabulated with demand for dentures (Table 4) some interesting results were obtained. However, the number of respondents particularly from small country towns was too small for the figures to be statistically significant. A much larger survey would have to be undertaken to determine if any real difference exists. Also, it must be remembered that there are differences in social class structures in towm and country; consequently, if any differences exist, they could be due to class factors rather than geographical environment. Denture wearing history - Respondents were questioned concerning the use of dentures, if any.
Table 5. Denture wearing history
Social class — Respondents were questioned about education and about the main occnpation of the head of the household and asked to describe this in a few words. Occupation is regarded by sociologists as the best single indicator of social class'. In those cases where a description was vague, for example "engineer", edueation was taken into consideration in making the classification. Respondents were then categorized into seven groups" as follows: Group 1: professional and higher management; Group 2: semi-professional, usually with a degree or degree equivalent, for example teaching diploma; Group 3 : middle management and small business-
n
Percent of respondents
Do not possess dentures Possess dentures but do not wear them Dentures 5 years old or less Dentures 6-10 years old Dentures 11 or more years old Unanswered
187 6
47.5 1.5
69 53 76 3
17.5 13.5 19.2 0.8
Total
394
Denture wearing history
and the age of those dentures (Table 5 ) . If the group w h o did not possess dentures are eliminated these results can be expressed as a percentage of denture wearers (Table 6 ) . FENN, LIDDELOW & GIMSON" state that "as a general rule most dentures require replacing within three to five years", but clinical experience would indicate that dentures up to the age of 5 years are probably satisfactory, those 6 - 1 0 years old are probably in need of replacement, and dentures over 11 years old are almost certainly in need of replacement.
100
Table 6. Denture wearing history of "dentnre wearers" Percent of "denture n wearers'" Possess dentures but do not wear them Dentures 5 years old or less Dentures 6-10 years old Dentures 11 or more years old
6
2.9
69 53 76
33.S 25.9 37.2
154
SPRATLEY
Table 9. Cros.s-tabulation of dental state by social class
Table 7. Distribution according to social class Percent of respondents
Social class
3.3 10.4 30.2 22.1
13 41 119 87 70 30 34
1 2 3 4 5
1 2 3
17.7 7.6 8.6
4 5
F 0
•
13 (100) 30 (73.2) 60 (50.4) 44 (50.6) 23 (32.8) 15 (50.0) 8 (23.5)
0 (0) 8 (19.5) 31 (26.1) 21 (24.1) 20 (28.6) 7 (23.3)
7 (20.6)
Fully edentulous (%of class) 0 (0)
3 28 22 27 8 19
( 7.3)
(23.5) (25.3) (38.6) (26.7) (55.9)
100
394
man; persons with specialist training and some degree of responsibility: Group 4: skilled workers or tradesmen; Group 5: unskilled workers, labourers and process workers; Group F: Farmers; because of the great diversity among farmers, it was eonsidered advisable to classify them separately; Group 0: Respondents who did not answer the question and could not be classified. If the figures in Table 7 are compared with those from the Victorian Year Book''', certain discrepancies are apparent. As might be expected, the higher and middle social classes responded more readily to the survey"; groups 4 and 5 for instance, equate to 47 % of the population according to the Year Book figures, but only 40 %< among the respondents. This middle elass bias is almost inevitable among surveys of this nature and must be considered when interpreting the results. A cross-tabulation of social class against demand for dentures (Table 8) shows that the further down Table 8. Cross-tabulation of social class by demand for dentures
Social class
No. demanding dentures
Percent of class
Percent of respondents demanding dentures
1
0
0
0
2 3 F
4 20 15 23 5
0
8
10 16.8 17.6 33.8 16.7 28.8
5.3 26.7 20.0 30.7 6.7 10.6
4
Fully or near Partially fully dentate edentulous (7 (% of class) n (% of class)
Soeial class
the social scale, the greater the demand for dentures. The lower class loading is even more pronouneed if the numbers are expressed in terms of percentage of respondents demanding dentures. It must be retnetnbered that as there was a relatively poor respotise from classes 4 and 5, these figures are probably artificially depressed. A cross-tabulation of social class against dental state (Table 9) reveals a similar pattern to the last table, with a much larger percentage of edentulous respondents in social class 5; farmers again display similar characteristics to social class 3. Age - Respondents were grouped in decades with the exception of the last two groups, 60-65 and over 65. Sixty-five, being the retirement age for many people, has social and economie implications. A cross-tabulation of age by dental state (Table lOA) shows the edentate proportion to be increasing with age. A cross-tabulation of age by denture wearing history (Table lOB) revealed that older people tend to have older dentures; this is particularly true of the 65 -j- age group, with over half the respondents having dentures 11 years old or older. This is very likely due to lack of money or motivation or both. If these figures are expressed as a proportion of that denture wearing group, they show that 36.8 % (28 out of a total of 76) of people wearing dentures 11 years or older, are in the 65 4- age group and therefore likely to be eeonomieally disadvantaged.
•ft
Cost — These were leading questions and included partly to encourage replies, which ninst he remembered when interpreting the results. The vast majority, 86.8 % of the respondents, considered dental care to be expensive but when asked if they would attend more regularly if it were cheaper, only 51.5 %' said they would. It is difficult to draw con-
Demand for prosthetic treatment 155 T a b l e 10. A) Cross-tabulation of age against dental state Age group Percent of age group fully edentulous («)
20-29
30-39
40-49
50-59
60-65
65 +
4.7 (4)
13.0
24.7 (19)
33.33 (22)
48.4
(9)
(15)
68.5 (37)
2.4
8.7
22.4
26.2
19.4
51.9
m 2.6
(6) 7.9
(17) 22.4
(17) 22.4
(6) 7.9
(28) 36.8
B) Cross-tabulation of age against denture wearing history Percent of 11 years («) Percent of 1 1 years
age group wearing dentures or older persons wearing a denture or older in age gt-onp
elusions from this, but it would seem that although cost must inevitably influence decisions, it is probably not the overriding factor. ADVANCFD DENTAL TECHNICIANS' SURVEY Unfortunately, the response was somewhat disappointing, being in the region of 60 %, which was in spite of appeals to their Association and reminder letters. It must be pointed out that the Advanced Dental Technicians have a chequered history involving much political nianoeuvering, consequently they may be sensitive to officialdom. Patterns of work - In view of the backgronnd of the Advanced Dental Technicians, that they were drawn from the existing technicians and did not have any formal clinical training, it is not surprising that the group showed great diversity, particularly in their working patterns. Respondents were asked to place themselves into one of four groups and re-
sults showed that the largest group, about 69 %, were working mainly as clinicians but doing their own technical work (Table 11). Age — The age of respondents ranged from 29 to 68 years, the average being just over 49 years, wliich compares with the average age of dentists in Victoria as 40 years. Productivity - Respondents were asked how many dentures they inserted on average per month, the average being 22, or 11 complete denture patients per month. This figure is depressed somewhat by those still working principally as technicians and if these groups are eliminated, leaving only those working either as clinicians doing their own technical work or as clinicians employing other teehnicians, the average comes out at 26.7 dentures per month. Fees — The fees charged by Advanced Dental Technicians for full maxillary and mandibular den-
Table 11. Results according to work patterns
Group
Doing little or no clinical work*
n (%) 6 (8.1)
Aver. no. of units ins. per month
Aver, fee per F/F
Aver, age
Hours per week in lab
Hours per week with patients
2.5*
$162.5*
46.6
53.2
2.0*
Working principally as a technician doing some clinical work
14 (18.9)
13.1
$159.7
45.1
35.9
9.3
Working as a clinician doing own technical work
51 (68.9)
24.4
$156.5
50.9
29.6
12.2
**
46.0
Working principally as a clinician doing Uttle or no technical work
3 (4.1)
* Only two members of this group did any clinical work. ** With only three tnembers this gronp showed such diversity that these averages would be meaningless.
•X-K-
156
SPRATLEY
Table 12. Estimated fully edentulous persons in Victoria
Age group, years
Population in age group ('71 census)
Percent fully edentvilous in age group ('76 survey)
0-19 20-29 30-39 40-49 50-59 60-65 65-t-
1,317,212 549,375 425,542 435,482 343,605 136,174 294,961
4.7 13.0 24.7 33.3 48.4 68.5
Total
3,502,351
0*
No. fully edentulous Q.X-
25,820 55,320 107,564 114,420 65,908 202,016 571,048
* These figures are obviously depressed as a result of the small number in this age group questioned in the survey (very few a])pear on the electoral rolls). Unfortunately, no accurate figures are available for this age group.
tures varied from Australian $120 to $250 with an average of $155. This fee will probably rise independently of inflation as more Advanced Dental Technicians rely on clinical work as their principal source of income. Currently, many of them are still working principally as technicians, not having their own clinical premises and not employing staff and consequently their overheads are very low. Locality — Of the respondents about one-sixth described themselves as living in the country with the other five-sixths in the Melbourne metropolitan area. DENTISTS' SURVEY Of the 200 dentists surveyed, 146 replied; after eliminating the questionnaires returned undelivered and considering only the general practitioners, this represents an 85 % reply rate. Seventy-five percent of the respondents were practising in the metropolitan area - they would be serving just over 70 % of the Vietorian population so it would seem that the town is better supplied than the country, although the difference is small. The town dentists inserted an average of 45.0 full denture units (F/F = 2 units) and 24.7 partial denture units per year. Their country counterparts inserted an average of 118.8 fttll units and 62.6 partial units per year; the country dentists therefore inserted nearly three times as many dentures as their metropolitan colleagues.
DISCUSSION The population survey showed that 19.5 % of the respondents thought they needed new dentures. The total population on the electoral rolls from which the samples were drawn was just over 2,200,000therefore, there are in excess of 400,000 people in Victoria requiring new dentures. Nearly half of these are replacement full dentures suitable for treatment by Advanced Dental Technicians. However, these figures represent a static situation and do not necessarily relate to the ongoing state. Table 12 shows the percentage edentulous in each age group and the population represented, which indicates that there are over half a million fully edentulous persons in Victoria. Assuming that this figure remains reasonably static'" and that a 10-year replacement cycle for dentures is acceptable, then approximately 50,000 complete denture patients require treatment each year. SATISFYINC THE DEMAND Before attempting to consider the number of Advanced Dental Technicians required to satisfy this demand, some variables must be taken into consideration. Also, it must be remembered that with the poor response to the Advanced Dental Technician survey (about 60 %) the figures arrived at cannot neeessarily be relied on. Cost and insurance - Advanced Dental Technician fees are currently eonsiderably lower than those of dentists and although they can be expected to rise, they will almost inevitably be offering a less expensive service. The main health insurance schemes are offering dental benefits at extra cost, Medibank, an Australian Health Insurance Fund, currently allows 60 % of the cost of dentures with a maximum subsidy of $100, with replacement after 3 years. The cost of the scheme is about $35 per year so there is no advantage to the individual denture wearer although there probably is an advantage to those with families. Dentist or Advaneed Dental Technician? - Because of the large numbers of dentures having been made in recent years by technicians working illegally, it is impossible to say what proportion of full denture patients have been treated by dentists as against those by technicians. If, as is expected, the Advanced Dental Technicians offer a less expensive
Demand for prosthetic treatment
service, it may be that they will treat most of the full denture patients. Work patterns — Future generations of Advanced Dental Technicians may have a vastly different background with more clinical training, and their work patterns could change with more of them employing technicians. Productivity — With only three respondents to the Advanced Dental Technician survey in the eategory of clinicians doing little or no laboratory work and those giving very divergent figures, it is impossible to determine their real productivity. However, it -would not be unreasonable to assume that it would be similar lo thai of the dental hospital where one clinician plus fotir or five technicians treat about 900 complete dentnre patients per year'-. COMPARISON WITH OTHER AREAS Tasmania - Dental Mechanics who have been licensed to deal directly with the public have been practising in Tasmania for some years. Their work is limited to full dentures plus partial dentures which do not involve mouth preparation. There are currently 52 licensed Dental Mechanics registered and this number is said to be static (L. L. SHEA, personal communication). A course of training was instituted in 1968 and is about 4 weeks long. Six places are available per year but the course is said to be under-subscribed. The pass rate is about 50 % . Tasmania has a population of about 350,000 and there are about 100 dentists on the Register" of -which 90 are said to be actively practising". H o w much clinical work is being done by the licensed Dental Mechanics is unknown but it is likely that their main income is from technical rather than clinical work. Denmark - Chnical technicians are allowed to practice in Denmark and as far as can be ascertained, have not been regulated at all until recently (U. BERTRAM, personal communication). Again, their work is limited to full dentures plus partial dentures not involving mouth preparation. The population of Denmark is about 5 million and these are serviced by some 4,400 dentists (a dentist to population ratio of 1:1140 with 1:800 being the desired aim of the authorities). There are about 700 clinical technicians of which about 400 are said to be trained (they have their own training school independent of the dentists). A normal fee for a full denture for a clinical technician is about $230
157
compared with $300-$400 from a dentist (Denmark has a high cost of living with high salaries and extremely heavy taxation, so that these figures cannot be directly compared with those of Australia). In the 65+ age group, 64.7 % of the population are edentate"* compared with 68.5 % for Victorians. It is believed that the clinical technicians make about 50 % of the dentures and a ratio of no more than six elinical technicians to one dentist is considered desirable. For comparison, Victoria has approximately 1,100 dentists on the Register" giving a dentist to population ratio of 1:3000. There are about 500 registered technicians with 122 of these registered as Advanced Dental Technicians.
NUMBER OF ADVANCED DENTAL TECHNICIANS REQUIRED Because of the aforementioned variables, it is impossible to state categorically how many Advanced Dental Technicians are required. At the present time no further Advanced Dental Technicians are being added to the Register and quite a large proportion of the current group are approaching retirement age. From the aforementioned figures, it would appear that the present Advanced Dental Technician workforce is making a contribution of about 18,000 complete denture treatments per year to meet the potential demand of 50,000 patients per year. Discussion with Advanced Dental Technicians has indicated that more are appreeiating the value of employing technicians and concentrating on clinical work themselves. If one half of the present number of Advanced Dental Technicians concentrated on clinical work and employed teehnicians, then the demand in the foreseeable future can be easily met. It would seem reasonable, therefore, that any conrse should be designed for fairly small numbers but it must also be remembered that if the number of Advanced Dental Technicians working purely as clinicians is to increase, this will also require an increase in the number of general technicians.
Acknowledgements - Appreciation is expressed to Professor H. F. ATKINSON, University of Melbourne and Dr. K. Di-.MPSKV, LaTrobe University, for their advice with this work.
158
SPRATLEY
REFERENCES 1. ABRAHAMSON, M . , MizRtJCHi, E. H. & HottNUNG, C. A.:
Stratification and mobility. 1976, pp. 190-200.
MacMillan, New York
2. BROOM, L., LANCASTKK-JONES, F . & ZUHRZYCKI, J.: An
occupational classification of the Australian workforce. Aust. N.Z.J. Sociol. 1965: / : Suppl. 3. BURGESS, W . C . & BECK, D . J.: Survey of denture
wearers in New Zealand. 1968. N.Z. Dent. J. 1969: 65: 223-232. 4. DAVIES, G . N . & WALSH, J. P.: Survey of denture
wearers in New Zealand. N.Z. Dent. J. 1953: 49: 124133. 5. EVANS, G . G . & CI.I.LIKR, K . M . : A survey of tooth
loss in South Australia. Au.st. Dent. J. 1970: 15: 299302.
9. REUSS, G . F.: Differences between persons responding and not responding to a mailed questionnaire. Am. Sociol, Rev, 1943: 8.- 433-438. 10. Si'RATLEY, M. H.: An estimate of demand lor prosthetic dentistry in the year 2000. Au.^t. Dent. J, 1977: 22: 17-19. 11. Australian Government Publishing Service: Handbook of Health Manpower, Part 1. Canberra 1975, p. 42. 12. Royal Dental Hospital of Melbourne: 84th Annual Report for year ended 30th June, 1974. 13. Tasmanian Government Gazette, 1976: Dentists' Register. Dental Board of Tasmania 1976. 14. Victorian Government Gazette, 1976. Dentists' Register, Melbourne 1976. 15. Victorian Year Book 1976: Commonwealth Bureau of Census and Statistics, Victorian Office, Melbourne 1976.
6. FKNN, H . R . B., LiDDta.ow, K. P. & GIMSON, A. P.:
Clinical dental prostheties. Staples Press, London 1961, p. 256. 7. G11.1.1NG.S, B. R. D., DoDD, C , GRAHAM, G. H . & BAR-
NARD, P. D.: Full and partial denture survey. Aust. Dent. J. 1967: 12: 574-581. 8. GRABOWSKY, M . & BERTRAM, U . : Oral health status
and need of dental treatment in the elderly Danish population. Community Dent. Oral Epidemiol. 1975: 3: 108-114.
Address: Department oj Dental Prosthetics School oj Dental Science 711 Elizabeth Street Melbourne, 3000, Victoria Australia
Dent. Oral Epidemiol. 1978: 6'; 151-158
(Key words; dentures; (noslhetic hcahneni)
Supply and demand for prosthetic treatment in Victoria, Australia M.
H . SPRATLEY
Department Melbourne, . ._
.
of Dental Prosthetics, School of Dental Science, University of Melbourne, Australia .ABSTRACT - Surveys were conducted in Victoria, Australia, to estimate the demand for prosthetic treatment by examining the needs of a t-andomly selected gronp of the population. Similar surveys were conducted in relation to the contribution made by the dentists in Victoria and also that of a recently introduced group of workers, the Advanced Dental Technicians. It was found that approximately 19 % of the population required prosthetic treatment in the full denture field and that the existing dentists were not meeting this need. When the Advanced Dental Technicians are more fnlly engaged in clinical work, the need may well be met. (Accepted for publication 25 February 1978)
During the past 2 years a series of examinations was conducted by the Advanced Dental Technicians Qualifications Board (set up under the Dental Technicians Act, 1972; No. 8366, Victoria) at The Royal Dental Hospital of Melbourne, which resulted in over 120 Advanced Dental Technicians being licensed and allowed to deal directly with the public. Their service is limited to full dentures in already edentulous mouths free of pathology, plus -relines and repairs in similar situations. Obviously this will have some impact on organized dentistry in Victoria and therefore it was decided to survey the population to determine the demand and requirement for prosthetic services. In conjunction with this, two more postal surveys were to be conducted; one of all those Advanced Dental Technicians already licensed, a total of 122, and another of a random sample of 200 dentists taken from the Dental Register of Victoria, to attempt to determine the part they could play in satisfying this demand.
MATERIAL AND METHODS P O P U L A T I O N SURVEY Recent surveys on dental health in Australia by GILLINGS, DoDD, GRAHAM & BARNARD'^ and EVANS & CELEIER-'' were
of patients rather than of a sample of the popnlation as a whole and it was decided therefore that a sui-vey of a sample chosen from the electoral rolls for Victoria would meet the requirements of this study. A postal sun'ey was chosen in preferenee to face-to-face inter\'iews because it was felt that some of the questions may have been somewhat embarrassing to the respondents and that there may have been some reluctance to discuss inthnate details with a complete stranger. However, postal sui-veys have a notoriously low reply rate. A not dissimilar sui-vey carried out by DA^-ll•;s & W.XLSH^ in New Zealand had a reply rate of only 38.5 %. That suivey could be criticized in as much as the questionnaire was heavily loaded prosthetically, which could account for the very high percentage, 72.9 %, of the respondents wearing dentures. In a more recent survey (1968) in New Zealand carried out by BURGESS & BECK', the reply rate was improved to 66.4 % by use of publicity in the media. However, similar criticisrns could still be levelled at the design of the questionnaire. Consequently, a pilot suivey was carried out of 50 peo])le whose names were chosen at random from the Melbourne telephone directory. The pilot survey received a response rate in excess of 60 % in spite of the fact that a reminder letter was not used. The sample for the main survey was chosen from the electoral rolls for Victoria, which include most adults of 18 years and above. Although this excludes a large proportion of the population, it was felt that denture wearing among the younger age groups, although not uncommon, would represent a small percentage of the demand overall. Other disadvantages of the electoral rolls are that there are many
152
SPRATLEY
reeent migrants who are not listed and the rolls at any one time will never be completely up to date. A total sample of 500 was chosen, representing 0.022 "/o of the population on the electoral rolls. A |)redetermined number of names was chosen at random from each electorate in proportion to the relative size of that electorate. Each person chosen was sent a covering letter, questionnaire and stamped addressed envelope. Those not replying after 3 weeks were sent a second questionnaire with a further covering letter. After excluding those letters returned "address unknown" or "deceased", the response rate was in excess of 80 %. A variety of questions were a.sked iticluding respondent's age, sex, dental state, denture wearing history and demand for all forms of dental treatment. Questions were included concerning occupation and education to act as indicators of social class and also questions about locality. Questions concerning attitude towards the cost of dentistry were asked in order to increase interest in the survey, thus improving the reply rate. Care was taken to avoid the survey appearing to be loaded towards the denture wearers, i.e. questions were worded to encovirage those people not wearing dentures to reply. The results were processed by cotiiputer at LaTrobe University.
RESULTS POPULATION SURVEY Dental state - Respondents were asked how many of their own teeth they had and they were required to fit them.selves into one of three groups: "All or most", "some" and "none". These groups were considered as fully or near fully dentate, partially dentate and edentate, respeetively (Table 1). These figures are somewhat similar to those of surveys in other States in recent years. Demand for dental treatment — Respondents were asked if they thought they needed dental treatment at the time of reply and if so, what its nature was (Table 2). There was an overlap as some individuals demanded more than one form of treatment; although it would have been possible to separate this overlap using the computer, it has not
No. of respondents
Percent of total
Fully or near fully dentate Partially edentulous Fully edentulous
193
49
94 107
24 27
Total
394
100
Table 2. Demand for dental treatment No. of respondents
Percent of total
75
19 23 13 6
Demanded dentures Demanded "fillings" Demanded extractions Demanded "gum treatment"
88
51 23
beeti done for the pitrposes of this paper. A crosstabulation of dental state by demand for dentures showed that 14.7 % of those demanding dentures could be classified as fully or near fully dentate. A further 38.7 % were partially dentate and 46.7 % edentate. The first two groups, the fully and partially dentate, eould be demanding either partial or immediate dentures and there is no practical way of distinguishing them, but the third group, 9.1 % of the total respondents, must be demanding full dentures. Sex - Of the replies, 54 % were from males and 46 % from females, which is of some interest as females make up approximately 52 % of the population on the electoral rolls. A cross-tabulation of detital state by sex (Table 3) shows that the pereentages of males and females elassified as fully or near fully dentate are similar, while a smaller pereentage of females could be elassified as partially edentate with the larger percentage edentate; this may be explained in part by age discrepancies, females having a longer life expeetaney and representing a larger proportion of the older age group than the males. A cross-tabulation of sex against demand shows that of the respondents deniandini> dentures, 48.6 %> were male and 51.4 % female.
Table 3. Cross-tabulation of dental state by sex (54 % of respondents were male eompared with only 48 % of the ]5opulation) Malerespondents " (%)
Female respondents n (%)
Fully or near fully dentate Partially edentulous Fully edentulous
105 (49.5%)
88 (48.9%)
57 (26.9%) 50 (23.6%)
37 (20.6%) 55 (30.6%)
Total
2!2
180
Dcmnnd for proslhetic treatment
153
T a b l e 4. Cross-tabulation of locality against demand for dentures No. of respondents from locality
Percent of total res])ond.
No. of respond. demanding dentures
Percent of respond. from locality
263
67.6
47
18.1
Large country town ( > 3,000 pop.)
74
19.0
15
20.5
Small country town ( < 3,000 pop.) or remote area
52
13.4
12
23.1
Locality Melbourne metropolitan area
74
389
Total
T h i s difference is not statistically significant. Howe v e r if (-lie slightly poorer response from females is t a k e n into consideration, it may indicate that more f e m a l e s than males are actually demanding dentures. Locality — Over two-thirds of the respondents -were living in the Melbourne metropolitan area. Comparison with figures from the Victorian Year Book'"' indicate that the reply rate was not biased tov^ards town or country. When locality was crosstabulated with demand for dentures (Table 4) some interesting results were obtained. However, the number of respondents particularly from small country towns was too small for the figures to be statistically significant. A much larger survey would have to be undertaken to determine if any real difference exists. Also, it must be remembered that there are differences in social class structures in towm and country; consequently, if any differences exist, they could be due to class factors rather than geographical environment. Denture wearing history - Respondents were questioned concerning the use of dentures, if any.
Table 5. Denture wearing history
Social class — Respondents were questioned about education and about the main occnpation of the head of the household and asked to describe this in a few words. Occupation is regarded by sociologists as the best single indicator of social class'. In those cases where a description was vague, for example "engineer", edueation was taken into consideration in making the classification. Respondents were then categorized into seven groups" as follows: Group 1: professional and higher management; Group 2: semi-professional, usually with a degree or degree equivalent, for example teaching diploma; Group 3 : middle management and small business-
n
Percent of respondents
Do not possess dentures Possess dentures but do not wear them Dentures 5 years old or less Dentures 6-10 years old Dentures 11 or more years old Unanswered
187 6
47.5 1.5
69 53 76 3
17.5 13.5 19.2 0.8
Total
394
Denture wearing history
and the age of those dentures (Table 5 ) . If the group w h o did not possess dentures are eliminated these results can be expressed as a percentage of denture wearers (Table 6 ) . FENN, LIDDELOW & GIMSON" state that "as a general rule most dentures require replacing within three to five years", but clinical experience would indicate that dentures up to the age of 5 years are probably satisfactory, those 6 - 1 0 years old are probably in need of replacement, and dentures over 11 years old are almost certainly in need of replacement.
100
Table 6. Denture wearing history of "dentnre wearers" Percent of "denture n wearers'" Possess dentures but do not wear them Dentures 5 years old or less Dentures 6-10 years old Dentures 11 or more years old
6
2.9
69 53 76
33.S 25.9 37.2
154
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Table 9. Cros.s-tabulation of dental state by social class
Table 7. Distribution according to social class Percent of respondents
Social class
3.3 10.4 30.2 22.1
13 41 119 87 70 30 34
1 2 3 4 5
1 2 3
17.7 7.6 8.6
4 5
F 0
•
13 (100) 30 (73.2) 60 (50.4) 44 (50.6) 23 (32.8) 15 (50.0) 8 (23.5)
0 (0) 8 (19.5) 31 (26.1) 21 (24.1) 20 (28.6) 7 (23.3)
7 (20.6)
Fully edentulous (%of class) 0 (0)
3 28 22 27 8 19
( 7.3)
(23.5) (25.3) (38.6) (26.7) (55.9)
100
394
man; persons with specialist training and some degree of responsibility: Group 4: skilled workers or tradesmen; Group 5: unskilled workers, labourers and process workers; Group F: Farmers; because of the great diversity among farmers, it was eonsidered advisable to classify them separately; Group 0: Respondents who did not answer the question and could not be classified. If the figures in Table 7 are compared with those from the Victorian Year Book''', certain discrepancies are apparent. As might be expected, the higher and middle social classes responded more readily to the survey"; groups 4 and 5 for instance, equate to 47 % of the population according to the Year Book figures, but only 40 %< among the respondents. This middle elass bias is almost inevitable among surveys of this nature and must be considered when interpreting the results. A cross-tabulation of social class against demand for dentures (Table 8) shows that the further down Table 8. Cross-tabulation of social class by demand for dentures
Social class
No. demanding dentures
Percent of class
Percent of respondents demanding dentures
1
0
0
0
2 3 F
4 20 15 23 5
0
8
10 16.8 17.6 33.8 16.7 28.8
5.3 26.7 20.0 30.7 6.7 10.6
4
Fully or near Partially fully dentate edentulous (7 (% of class) n (% of class)
Soeial class
the social scale, the greater the demand for dentures. The lower class loading is even more pronouneed if the numbers are expressed in terms of percentage of respondents demanding dentures. It must be retnetnbered that as there was a relatively poor respotise from classes 4 and 5, these figures are probably artificially depressed. A cross-tabulation of social class against dental state (Table 9) reveals a similar pattern to the last table, with a much larger percentage of edentulous respondents in social class 5; farmers again display similar characteristics to social class 3. Age - Respondents were grouped in decades with the exception of the last two groups, 60-65 and over 65. Sixty-five, being the retirement age for many people, has social and economie implications. A cross-tabulation of age by dental state (Table lOA) shows the edentate proportion to be increasing with age. A cross-tabulation of age by denture wearing history (Table lOB) revealed that older people tend to have older dentures; this is particularly true of the 65 -j- age group, with over half the respondents having dentures 11 years old or older. This is very likely due to lack of money or motivation or both. If these figures are expressed as a proportion of that denture wearing group, they show that 36.8 % (28 out of a total of 76) of people wearing dentures 11 years or older, are in the 65 4- age group and therefore likely to be eeonomieally disadvantaged.
•ft
Cost — These were leading questions and included partly to encourage replies, which ninst he remembered when interpreting the results. The vast majority, 86.8 % of the respondents, considered dental care to be expensive but when asked if they would attend more regularly if it were cheaper, only 51.5 %' said they would. It is difficult to draw con-
Demand for prosthetic treatment 155 T a b l e 10. A) Cross-tabulation of age against dental state Age group Percent of age group fully edentulous («)
20-29
30-39
40-49
50-59
60-65
65 +
4.7 (4)
13.0
24.7 (19)
33.33 (22)
48.4
(9)
(15)
68.5 (37)
2.4
8.7
22.4
26.2
19.4
51.9
m 2.6
(6) 7.9
(17) 22.4
(17) 22.4
(6) 7.9
(28) 36.8
B) Cross-tabulation of age against denture wearing history Percent of 11 years («) Percent of 1 1 years
age group wearing dentures or older persons wearing a denture or older in age gt-onp
elusions from this, but it would seem that although cost must inevitably influence decisions, it is probably not the overriding factor. ADVANCFD DENTAL TECHNICIANS' SURVEY Unfortunately, the response was somewhat disappointing, being in the region of 60 %, which was in spite of appeals to their Association and reminder letters. It must be pointed out that the Advanced Dental Technicians have a chequered history involving much political nianoeuvering, consequently they may be sensitive to officialdom. Patterns of work - In view of the backgronnd of the Advanced Dental Technicians, that they were drawn from the existing technicians and did not have any formal clinical training, it is not surprising that the group showed great diversity, particularly in their working patterns. Respondents were asked to place themselves into one of four groups and re-
sults showed that the largest group, about 69 %, were working mainly as clinicians but doing their own technical work (Table 11). Age — The age of respondents ranged from 29 to 68 years, the average being just over 49 years, wliich compares with the average age of dentists in Victoria as 40 years. Productivity - Respondents were asked how many dentures they inserted on average per month, the average being 22, or 11 complete denture patients per month. This figure is depressed somewhat by those still working principally as technicians and if these groups are eliminated, leaving only those working either as clinicians doing their own technical work or as clinicians employing other teehnicians, the average comes out at 26.7 dentures per month. Fees — The fees charged by Advanced Dental Technicians for full maxillary and mandibular den-
Table 11. Results according to work patterns
Group
Doing little or no clinical work*
n (%) 6 (8.1)
Aver. no. of units ins. per month
Aver, fee per F/F
Aver, age
Hours per week in lab
Hours per week with patients
2.5*
$162.5*
46.6
53.2
2.0*
Working principally as a technician doing some clinical work
14 (18.9)
13.1
$159.7
45.1
35.9
9.3
Working as a clinician doing own technical work
51 (68.9)
24.4
$156.5
50.9
29.6
12.2
**
46.0
Working principally as a clinician doing Uttle or no technical work
3 (4.1)
* Only two members of this group did any clinical work. ** With only three tnembers this gronp showed such diversity that these averages would be meaningless.
•X-K-
156
SPRATLEY
Table 12. Estimated fully edentulous persons in Victoria
Age group, years
Population in age group ('71 census)
Percent fully edentvilous in age group ('76 survey)
0-19 20-29 30-39 40-49 50-59 60-65 65-t-
1,317,212 549,375 425,542 435,482 343,605 136,174 294,961
4.7 13.0 24.7 33.3 48.4 68.5
Total
3,502,351
0*
No. fully edentulous Q.X-
25,820 55,320 107,564 114,420 65,908 202,016 571,048
* These figures are obviously depressed as a result of the small number in this age group questioned in the survey (very few a])pear on the electoral rolls). Unfortunately, no accurate figures are available for this age group.
tures varied from Australian $120 to $250 with an average of $155. This fee will probably rise independently of inflation as more Advanced Dental Technicians rely on clinical work as their principal source of income. Currently, many of them are still working principally as technicians, not having their own clinical premises and not employing staff and consequently their overheads are very low. Locality — Of the respondents about one-sixth described themselves as living in the country with the other five-sixths in the Melbourne metropolitan area. DENTISTS' SURVEY Of the 200 dentists surveyed, 146 replied; after eliminating the questionnaires returned undelivered and considering only the general practitioners, this represents an 85 % reply rate. Seventy-five percent of the respondents were practising in the metropolitan area - they would be serving just over 70 % of the Vietorian population so it would seem that the town is better supplied than the country, although the difference is small. The town dentists inserted an average of 45.0 full denture units (F/F = 2 units) and 24.7 partial denture units per year. Their country counterparts inserted an average of 118.8 fttll units and 62.6 partial units per year; the country dentists therefore inserted nearly three times as many dentures as their metropolitan colleagues.
DISCUSSION The population survey showed that 19.5 % of the respondents thought they needed new dentures. The total population on the electoral rolls from which the samples were drawn was just over 2,200,000therefore, there are in excess of 400,000 people in Victoria requiring new dentures. Nearly half of these are replacement full dentures suitable for treatment by Advanced Dental Technicians. However, these figures represent a static situation and do not necessarily relate to the ongoing state. Table 12 shows the percentage edentulous in each age group and the population represented, which indicates that there are over half a million fully edentulous persons in Victoria. Assuming that this figure remains reasonably static'" and that a 10-year replacement cycle for dentures is acceptable, then approximately 50,000 complete denture patients require treatment each year. SATISFYINC THE DEMAND Before attempting to consider the number of Advanced Dental Technicians required to satisfy this demand, some variables must be taken into consideration. Also, it must be remembered that with the poor response to the Advanced Dental Technician survey (about 60 %) the figures arrived at cannot neeessarily be relied on. Cost and insurance - Advanced Dental Technician fees are currently eonsiderably lower than those of dentists and although they can be expected to rise, they will almost inevitably be offering a less expensive service. The main health insurance schemes are offering dental benefits at extra cost, Medibank, an Australian Health Insurance Fund, currently allows 60 % of the cost of dentures with a maximum subsidy of $100, with replacement after 3 years. The cost of the scheme is about $35 per year so there is no advantage to the individual denture wearer although there probably is an advantage to those with families. Dentist or Advaneed Dental Technician? - Because of the large numbers of dentures having been made in recent years by technicians working illegally, it is impossible to say what proportion of full denture patients have been treated by dentists as against those by technicians. If, as is expected, the Advanced Dental Technicians offer a less expensive
Demand for prosthetic treatment
service, it may be that they will treat most of the full denture patients. Work patterns — Future generations of Advanced Dental Technicians may have a vastly different background with more clinical training, and their work patterns could change with more of them employing technicians. Productivity — With only three respondents to the Advanced Dental Technician survey in the eategory of clinicians doing little or no laboratory work and those giving very divergent figures, it is impossible to determine their real productivity. However, it -would not be unreasonable to assume that it would be similar lo thai of the dental hospital where one clinician plus fotir or five technicians treat about 900 complete dentnre patients per year'-. COMPARISON WITH OTHER AREAS Tasmania - Dental Mechanics who have been licensed to deal directly with the public have been practising in Tasmania for some years. Their work is limited to full dentures plus partial dentures which do not involve mouth preparation. There are currently 52 licensed Dental Mechanics registered and this number is said to be static (L. L. SHEA, personal communication). A course of training was instituted in 1968 and is about 4 weeks long. Six places are available per year but the course is said to be under-subscribed. The pass rate is about 50 % . Tasmania has a population of about 350,000 and there are about 100 dentists on the Register" of -which 90 are said to be actively practising". H o w much clinical work is being done by the licensed Dental Mechanics is unknown but it is likely that their main income is from technical rather than clinical work. Denmark - Chnical technicians are allowed to practice in Denmark and as far as can be ascertained, have not been regulated at all until recently (U. BERTRAM, personal communication). Again, their work is limited to full dentures plus partial dentures not involving mouth preparation. The population of Denmark is about 5 million and these are serviced by some 4,400 dentists (a dentist to population ratio of 1:1140 with 1:800 being the desired aim of the authorities). There are about 700 clinical technicians of which about 400 are said to be trained (they have their own training school independent of the dentists). A normal fee for a full denture for a clinical technician is about $230
157
compared with $300-$400 from a dentist (Denmark has a high cost of living with high salaries and extremely heavy taxation, so that these figures cannot be directly compared with those of Australia). In the 65+ age group, 64.7 % of the population are edentate"* compared with 68.5 % for Victorians. It is believed that the clinical technicians make about 50 % of the dentures and a ratio of no more than six elinical technicians to one dentist is considered desirable. For comparison, Victoria has approximately 1,100 dentists on the Register" giving a dentist to population ratio of 1:3000. There are about 500 registered technicians with 122 of these registered as Advanced Dental Technicians.
NUMBER OF ADVANCED DENTAL TECHNICIANS REQUIRED Because of the aforementioned variables, it is impossible to state categorically how many Advanced Dental Technicians are required. At the present time no further Advanced Dental Technicians are being added to the Register and quite a large proportion of the current group are approaching retirement age. From the aforementioned figures, it would appear that the present Advanced Dental Technician workforce is making a contribution of about 18,000 complete denture treatments per year to meet the potential demand of 50,000 patients per year. Discussion with Advanced Dental Technicians has indicated that more are appreeiating the value of employing technicians and concentrating on clinical work themselves. If one half of the present number of Advanced Dental Technicians concentrated on clinical work and employed teehnicians, then the demand in the foreseeable future can be easily met. It would seem reasonable, therefore, that any conrse should be designed for fairly small numbers but it must also be remembered that if the number of Advanced Dental Technicians working purely as clinicians is to increase, this will also require an increase in the number of general technicians.
Acknowledgements - Appreciation is expressed to Professor H. F. ATKINSON, University of Melbourne and Dr. K. Di-.MPSKV, LaTrobe University, for their advice with this work.
158
SPRATLEY
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Stratification and mobility. 1976, pp. 190-200.
MacMillan, New York
2. BROOM, L., LANCASTKK-JONES, F . & ZUHRZYCKI, J.: An
occupational classification of the Australian workforce. Aust. N.Z.J. Sociol. 1965: / : Suppl. 3. BURGESS, W . C . & BECK, D . J.: Survey of denture
wearers in New Zealand. 1968. N.Z. Dent. J. 1969: 65: 223-232. 4. DAVIES, G . N . & WALSH, J. P.: Survey of denture
wearers in New Zealand. N.Z. Dent. J. 1953: 49: 124133. 5. EVANS, G . G . & CI.I.LIKR, K . M . : A survey of tooth
loss in South Australia. Au.st. Dent. J. 1970: 15: 299302.
9. REUSS, G . F.: Differences between persons responding and not responding to a mailed questionnaire. Am. Sociol, Rev, 1943: 8.- 433-438. 10. Si'RATLEY, M. H.: An estimate of demand lor prosthetic dentistry in the year 2000. Au.^t. Dent. J, 1977: 22: 17-19. 11. Australian Government Publishing Service: Handbook of Health Manpower, Part 1. Canberra 1975, p. 42. 12. Royal Dental Hospital of Melbourne: 84th Annual Report for year ended 30th June, 1974. 13. Tasmanian Government Gazette, 1976: Dentists' Register. Dental Board of Tasmania 1976. 14. Victorian Government Gazette, 1976. Dentists' Register, Melbourne 1976. 15. Victorian Year Book 1976: Commonwealth Bureau of Census and Statistics, Victorian Office, Melbourne 1976.
6. FKNN, H . R . B., LiDDta.ow, K. P. & GIMSON, A. P.:
Clinical dental prostheties. Staples Press, London 1961, p. 256. 7. G11.1.1NG.S, B. R. D., DoDD, C , GRAHAM, G. H . & BAR-
NARD, P. D.: Full and partial denture survey. Aust. Dent. J. 1967: 12: 574-581. 8. GRABOWSKY, M . & BERTRAM, U . : Oral health status
and need of dental treatment in the elderly Danish population. Community Dent. Oral Epidemiol. 1975: 3: 108-114.
Address: Department oj Dental Prosthetics School oj Dental Science 711 Elizabeth Street Melbourne, 3000, Victoria Australia
