Adults' dental treatment in 2001-2013 in Finnish public dental service.

BACKGROUND
All adults over 17 years of age have access to the Public Dental Service after the Finnish Dental Care Reform in 2001-2002. This study aimed to survey the treatment needs and treatment measures provided for adult patients and changes in these during the period 2001-2013.


METHODS
Sing each person's unique identifier, demographic data on dental visits during the period 2001-2013 were collected from municipal databases in five PDS-units covering 320,000 inhabitants. The numbers of visitors, those in need of basic periodontal or caries treatment (CPI > 2 and D + d > 0) were calculated for three age groups. Treatment provided was also calculated in 13 treatment categories. Trend analyses were performed to study changes during the study period.


RESULTS
Restorative treatments (968,772; 23.6%), examinations (658,394; 16.1%), radiographs taken (529,875; 12.9%) anaesthesia used (521,169; 12.7%) and emergency treatments (348,229; 8.5%) made up 73.8% of all treatment measures during the entire study period. Periodontal treatment (7.8%) and caries prevention (3.9%) made up a small part of the care provided and prosthetics and treatment of TMJ disorders were extremely uncommon (fewer than 1%). Treatments related to caries (restorative treatment, examinations, endodontics, emergencies, anaesthesia and radiographs) made up 60.4% of the dental personnel's treatment time. During the study period, statistically significant increasing trends were found for radiographs (p < 0.001***), anaesthesia (p = 0.003**) and total number of treatments (p = 0.009**). There was a slight decreasing trend in treatment need among the youngest adults (18-39 years; p = 0.033*).


CONCLUSION
Compared with the results of national epidemiological studies, insufficient periodontal treatment is provided and prosthetic treatment is almost totally neglected in the PDS. Rather, adults' dental treatment concentrates on treatment of caries. The unmet needs may be due to tradition, inadequate treatment processes or a lack of resources or failed salary incentives.


Background
In Finland, adults' oral health has been monitored by three nationally representative clinical epidemiological studies in 1980, 2000 and 2011 [1][2][3]. These studies have shown that adults in general have poor oral health: they have lost many teeth and edentulousness is still common, especially among the elderly. Caries prevalence has decreased slightly [1][2][3] but the periodontal conditions have not improved during recent decades [1][2][3][4]. Home care habits are not good [3]. In the neighbouring countries, Sweden and Denmark progress has been much better [5,6]. In Germany, adults have better oral health [7].
Since the early 1970s, the Public Dental Service (PDS) has catered for most children and adolescents younger than 18 years. It offered examinations, prevention and all necessary care free of charge [8]. Since the 1980s, adults were successively given access to the subsidized dental services in the PDS, starting with the 18-25-year-olds youngest age groups. Older adults were assumed to visit private dentists or clinical dental technicians (denturists) and pay for their treatments out-of-pocket [9].
The Dental Care Reform in 2001-2002 abolished all age restrictions and persons older than 46 years (born before 1956) were allowed to book appointments in the PDS [9]. After the onset of the Reform from 2001 to 2007, adults' use of oral health services increased, perceived need for oral health care decreased and socioeconomic inequity in use of care decreased. However, socioeconomic inequalities in reporting the need for emergency care increased [10]. In the PDS, a third (36.4%) of all treatment measures were still provided for children and adolescents in 2009 and waiting lists for adults were long [11]. About half (48.5%) of the working aged (18-64-year-olds) who visited a dentist in 2009 had used private services and the other half (51.5%) public services. Of the elderly (65+ years), 56.9% had visited private dentists and 43.1% public dentists [12].
There are few studies on dental treatment provided in general [6,13,14] and especially in a longitudinal perspective. Overall, developing outcome measures for oral health care and using them for evaluation and steering purposes is still just beginning [15].
The aim of this study was to survey treatment needs and treatment measures provided for adults over 17 years old in the Public Dental Service and changes in them during a 13-year period from 2001 to 2013.

Methods
As described in our previous article [8] we asked five PDS units in southern Finland, where the same specific electronic patient registration system [16] was in use, were asked to participate in the study. Ethical approval was provided by the National Institute for Health and Welfare (THL 1697284289204448) and permission to use the local data was granted by the directors of health services in each PDS unit. The total number of adult inhabitants (> 17 years) in the participating PDS units' catchment areas was in 2001, 240,584 and in 2013, 262,703 persons [17].
Data on all the adults (> 17 years) who had visited the five PDS units during 2001-2013 were collected retrospectively from each municipal database. For each year, the numbers of all patients who had visited a dentist and all treatment measures provided by any professional category (dentists, dental hygienists and dental nurses) were extracted from the databases [8]. Data on need for basic periodontal or caries treatment (CPI > 2, D + d > 0) [18] were also collected.
To control the possible effect of some treatment measures being short and others time consuming, all treatment measures collected were converted into treatment time (minutes, hours) using the average durations of the treatment measures as observed in a recent Finnish study [19].
The R 3.3 environment for statistical computing was used for descriptive and inferential analyses. Annual numbers of patients, the numbers of the examined, those in need of treatment and sum of treatment categories as well as their proportions of total are presented [8]. Numbers of treatment measures per 1000 patients combined by age group are also presented.
To discover underlying trends, we modeled volumes of patients in treatment categories, total treatment need, agreement of treatment needs and the volume of preventive treatment as functions of year. After logarithmic transformation of volumes, our linear models assume constant percentage change over time, with deviations from the mean normal on the log-scale and with explicitly autocorrelated residuals [20]. Fits to data were adequate except for very low-volume categories of TMJ disorders and prosthetics. Significances are reported at the level p < 0.05 [8].

Results
From the first study year (2001) to the last (2013), the number of adults having visited the PDS increased by 81.5% from 37,377 to 67,834. The number of patients in the youngest age group (18-39-year-olds) increased only by 6.5% from 25,463 to 27,113. The age group 39-64years-old increased by 183.5% from 9760 to 27,666 and the oldest group (65+ years) increased five-fold from 2154 to 13,055 ( Table 1). The total number of adults treated during the 13-year study period was 203,619 (Table 1). This means that about 77.5% of the adult population had visited the PDS on one or more occasions during 2001-2013.
During the study period, the proportion of those in need of basic caries and periodontal treatment (CPI > 2, D + d > 0) decreased slightly. A statistically significant decreasing trend could be found in the youngest age group (18-39 years) from 75 to 68% (p = 0.033*). In the age group 40-64 years the decrease was smaller, from 74 to 70% and the trend was not significant (p = 0.497). In the oldest age group (65 + years) the corresponding figures were from 61 to 55% (p = 0.394; Table 1; Table 3). Table 1 Numbers and distribution (%) of adults (> 17 years), total and by age group (18- Patients, all and number in the category  Table 1 Numbers and distribution (%) of adults (> 17 years), total and by age group (18- (Table 3).
As can be seen from Table 2, a major part of all preventive treatment (43.5%) was provided for the youngest adults and most periodontal treatment (45.5%), restorative treatment (45.8%) and prosthetics (52.0%) was for middle-aged adults. Other treatment categories were more evenly distributed among the age groups.
When treatment measures were converted into time [19], the share of periodontics doubled from 7.8 to 15.2% and endodontics from 5.3 to 11.6% respectively. The prosthetics share tripled from 0.9 to 2.7% but remained low. Radiology decreased from 12.9 to 3.2% and anaesthesia from 12.7 to 4.2%. The share of restorative treatment increased from 23.6 to 28.4% and preventive treatment from 3.9 to 4.8%. The share of examinations decreased slightly from 16.1 to 12.8% (Table 2). Treatments related to caries, restorative treatment (28.4%), examinations (12.8%), endodontics (11.6%) and emergency treatment (9.2%) made up 62.0% of dental personnel's treatment time ( Table 3).
The total number of treatment measures provided increased from 5402 to 7057 per 1000 patients. Among the youngest age category (18-39 years), the mean number of treatment measures increased from 5207 to 6781 per 1000 patients, among the 40-64-year-olds from 5806 to 7495 per 1000 patients and among the oldest (65+ years) from 5872 to 6701 per 1000 patients (Fig. 1, Table 3).
Restorative treatment decreased from 1520 to 1428 treatment measures per 1000 patients, preventive care from 314 to 164 and prosthetics from 89 to 57 treatment measures.
Examinations increased from 917 to 1182 items per 1000 patients, radiology from 548 to 1054 items, anaesthesia from 683 to 939, periodontics from 494 to 537, emergency treatment from 258 to 567 and endodontics from 253 to 362 treatment measures respectively (Table 3).
Preventive treatment measures decreased among the 18-39-year-olds from 245 to 153 among the 40-64-yearolds; from 416 to 130 items and among the 65+ year-olds the decrease was from 659 to 262 treatment measures per 1000 patients per year.
A statistically significant increasing trend was found in the total number of treatment measures provided from 2001 to 2013 for the youngest age group (18-39 years) (p = 0.003**) and for the 40-64-year-olds (p = 0.015*). For the oldest group (65+ years), the trend was not statistically significant. The increasing trends in radiology (p < 0.001***), anaesthesia (p = 0.003**) and oral surgery (p = 0.004**) were statistically significant. The decreasing trend in preventive care was statistically significant (p = 0.003**; Table 4).
There were on average almost five times (483.5%) more preventive treatment measures per patient among those not in need of treatment compared with those in need of treatment in every age group. In addition, among those in need of treatment there was a decreasing trend in preventive treatment measures per 1000 patients. Among the 40-64-year-olds from 2287 to 1383 (p = 0.569) and among the 65+ year-olds from 3759 to 1297 treatment measures per patient (p = 0.958; Table 3).

Discussion
In Finland, many kinds of statistical information on the performance of the public dental services have been collected by the individual PDS-units. Recording of certain oral health indices considering treatment needs and treatment measures is mandatory and part of each PDS dentist's salary is based on the treatment measures provided. Thus, data from the PDS records have been considered reliable [21]. There was little information about dental treatment provided in Finland before the national study in the year 2009 [11,12]. The treatment profiles in the PDS units participating in this study were in line with the previously mentioned national study [11] indicating that the chosen units, covering 5.9% of the population, were not outliers among the Finnish PDS-units. The results of this study can thus be generalised to middle sized or big towns in southern Finland. A limitation is that no information on social background of the patients is collected in the PDS register and that the information on treatment needs and oral health indicators was rather crude.
The results showed that from 2001 to 2013, the number of adults (18+ years) treated in the participating PDS-units increased by 81.5%. In 2001, the shares of young (< 18 years) and adult patients were 51.5 and 48.5% respectively and in 2013 these were 36.8 and 63.2% [22]. This change was in line with the political intentions of the Dental Care Reform in 2001 aiming to improve adults' access to the PDS.
Overall, during the 13-year study period, most adults living in the local municipalities (77.5%) had visited the PDS on some occasion. The legal obligation to organise emergency dental services for all inhabitants in its PDS uptake-area was included in the Dental Care Reform; this certainly explains a big part of the expanded use [23]. It was obvious from this study that most new patients were working age (18-64 years) adults. The share of older patients grew only from three to 12%. In 2000, 44% of the elderly were still edentulous in Finland [2]. During the study period, the number of dentists increased by 61.4% and the number of auxiliaries by 267.9% in the participating PDS units. The increased resources were used in treatment of adults only.
The study showed that the clinical treatment provided concentrated strongly on treating caries and its consequences. Examinations, restorative treatment, endodontics and emergencies made up 53.5% of all treatment measures and took 62.0% of the total treatment time of the staff during the whole study period. This can be regarded to be a disproportional share because the national epidemiological studies [1][2][3] have shown that, in addition to caries, gingivitis and periodontitis and great numbers of missing teeth even in anterior visible sectors without prosthetic devices are common in Finnish adults. Periodontal treatment made up only 7.8% of all treatment measures provided and 15.2% of the total treatment time. A worrying finding was that the share of preventive treatment was generally lower among those in need of treatment than those not in need of basic periodontal or restorative treatment.
Public dentists in Finland feel that their competence is weak in periodontal treatment [26]. This may be because dentists may think that much of this treatment should be given by the dental hygienists, but probably also because the PDS until 2002 catered mainly for children, adolescents and young adults. Lack of experience and skills is also likely to explain the fact that very little prosthetic treatment (0.2%) was provided by the participating PDS units. The cost of prosthetic treatment and especially fixed prosthetics has been high even in the PDS, because the technical work has to be bought from the private sector. The fact that some treatments are neglected also reflects lack of resources, especially specialists in adult dental care. Officially, prosthetics is included in the treatment palette of the PDS. Poor access to proper crown and bridge therapy and its high cost have resulted in restorative treatment practices where large composite fillings and crowns are used with wide indications, often leading to repetitive circle of restorative work and thus raising the share of restorative treatment [27]. Provision of questionable restorative treatment can also increase the need for endodontic treatment. In the national epidemiological study in 2000, 27% of the examined adults had at least one and 13% three or more teeth with apical periodontitis [2].
The public dentists (but not dental hygienists) have been encouraged to increase productivity by giving them salary increments from most treatment measures they have provided except radiography and preventive care. The salary increment is about 30-40% of the total wages. The most profitable treatments are and have long been examinations and restorative treatment. Thus, the findings reflect great discrepancy between the objectives of the Dental Care Reform in 2002 to give older adults born before the year 1956 access to the PDS and still continuing the use of old incentives aimed to steer productivity in treatment of young adults needing mostly treatment of caries when the incentives were created in 1980s.
Since this study period ended, a number of national best practice guidelines for most treatments in adult oral health care have been published to facilitate clinical treatment planning in Finland. These evidence-based recommendations include treatment of dental caries [28], temporomandibular disorders [29], restorative dentistry [30], dental infections [31] and prosthetics [32]. However, it is well-known that even the best guidelines will not become implemented automatically in daily practice but require education and leadership [33].
Overall, there has been little political pressure to look at the quality of adult dental care [34]. Chief medical officers, the superiors of the chief dental officers in the decentralised PDS organisation, are not sufficiently familiar with the challenges in adult dental care after the age restrictions were abolished in the PDS [35] and there has been no other interest group to drive this objective.
This study shows that use of routine administrative data collected from the databases of PDS organizations can improve transparency of oral health service delivery and give new tools for the managers and political leaders. The results also indicate that the PDS might be insufficiently resourced or the personnel is not efficiently used in providing care for adults. Besides the young, adults should also be included in a recall system in the PDS to guarantee improvement of their oral health. The present incentives connected with salary that favor selected treatment measures need to be replaced by a system that enables adequate comprehensive care and includes prevention.

Conclusions
Adults' dental treatment in the PDS concentrates on treatment of caries. Compared with the results of national epidemiological studies, periodontal treatment is insufficient and prosthetic treatment is almost totally neglected. The big increase in radiography suggests that the quality of examinations has improved. There was no