Dental implant therapy in the Brazilian Public System: an overview of the last decade

Aim: This retrospective study aims to describe and analyze the number of dental implants and implant-retained prostheses performed by the Unified Health System (SUS) in the last decade. Methods: This study is based on secondary data from the official government database (DATASUS) performed from January 2010 to December 2019 and is reported following the STROBE. A descriptive analysis was performed of the total sample and the stratified sample divided by Brazilian states. Results: A total of 143,037 dental implants and 93,325 implant-retained prostheses were provided by SUS. It is possible to observe that some states played a massive role on the provision of dental implants and implant-retained prostheses (Parana state: 58.4% and 55.9% and Paraiba state: 21.1% and 25.2% of the total amount of dental implants and implant-retained prostheses, respectively) while some states did not provide a single implant-retained prosthesis. Also, inland cities were mostly responsible for the number of procedures compared to the state capitals. Conclusion: Although dental implant therapy is available in SUS across the country, the number of treatments provided in the last decade is still very limited and is also mainly concentrated in the southeastern region of Brazil.


Introduction
Brazil is one of the few countries in the world to have a public health system that provides entirely free of cost services for any person, including foreigners. The Unified Health System (Sistema Unico de Saude -SUS) was instituted by the 1988constitution and is based on the principle that citizen's health is a constitutional right and state's duty 1 . Regarding to numbers, SUS is the largest public health system in the world considering the number of users, geographical extension, and size of the affiliated network 2 , whereas services are financed and provided at federal, state, or municipal levels.
In 2004, a nationwide program called "Smiling Brazil" included oral health as one of the priority areas of the SUS 1 . To do so, epidemiological census was conducted in the whole country and investments were made both in human resources (professional development) and infrastructure. The main focus of SUS and its "Smiling Brazil" program is related to primary care including oral hygiene instructions, dental restorations, root and scaling, and tooth extractions. This program also focus on the expansion and qualification of specialized treatment, which is also covered by SUS, including medium-complexity and tertiary care 2 .
The last Brazilian census on oral health have shown a high prevalence of edentulism in the elderly population (53.7%), while 17.4% of the Brazilian adults have at least one tooth loss 3 . Also, projections based on the population growth indicates that until 2040, 85.9% of the elderly population will have edentulous jaws 4 . In this perspective, oral rehabilitations with dental implants and implant-retained prostheses are considered the best treatment option to rehabilitate missing teeth, presenting high success and survival rates, as well as patients' satisfaction [5][6][7][8] .
Dental implants and implant-retained prostheses were introduced in SUS in 2010, through the Ministry of Health ordinances No 718/SAS/MS and No 398/SAS/MS 9,10 . To the best of our knowledge, the SUS is one of the few public health systems that offer dental implants in the public service. However, it seems that the provision of dental implant rehabilitation in Brazil is still mostly made by private practices. For this reason, this survey becomes important to assess the last decade of implants placement in the Brazilian public service, whilst the results could represent a tool for the policy-makers, aiming to reducing inequalities and improving the coverage of these treatments. Thus, the present study aims to describe and analyze the official government databank (DATASUS) regarding to dental implants, considering both the number of placed implants and implant-retained rehabilitations, made by SUS since the inclusion of these treatments in it.

Materials and methods
This retrospective study was designed as an ecologic study and is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and is based on secondary data from DATASUS (Brazilian health information databank) 11 . In accordance to a National Resolution (CNS, nº 510), the Ethics Committee Approval was not mandatory 12 .

Source
Data was acquired from DATASUS (Brazilian health information databank) using the TABNET tool, which provides information to support objective analyzes of the health situation, evidence-based decision making and the development of health action programs 13 .

Data acquisition
A search comprising keywords and SUS codes related to dental implants (osseointegrated dental implant -Code 0414020421; and implant-retained prosthesis -Code 0701070153) was performed considering all procedures performed in SUS from January 2010 to the end of December 2019. Data was collected on March 17 th , 2020. All inputs were analyzed and categorized into: a) Dental implants placement; b) Implant-retained prostheses. The distribution of the number of each procedure/treatment was also distributed according to Brazil's socio-demographic regions (south, southeast, northeast, north, and central-west) and states. A descriptive analysis of the total sample and the stratified sample divided by state was performed using Stata Software 14.0 (Stata Corporation, College Station, TX, USA). Table 1 summarizes the distribution of implant-related treatments provided by SUS considering all Brazilian states. In the last decade (January 2010 to December 2019), a total of 143,037 dental implants and 93,325 implant-retained prostheses were provided by SUS. In Figures 1 and 2, it is possible to observe that some states played a massive role on the provision of dental implants and implant-retained prostheses (Parana state: 58.4% and 55.9% of the total amount of dental implants and implant-retained prostheses, respectively; Paraiba state: 21.1% and 25.2% of the total amount of dental implants and implant-retained prostheses, respectively) while some states did not provide a single implant-retained prosthesis. Figure 3 presents the number of dental implants and implant-retained prostheses provided by SUS from January 2010 to December 2019. It is possible to observe a peak between the years of 2017, while a notable decrease was observed in the following years (2018-2019).

Results
In the

Discussion
The present study provides an insight of the SUS role in regard to oral rehabilitations using dental implants in the last decade (2010-2019). Although the incidence of tooth loss is decreasing worldwide in the last decades 14 and, according with the last epidemiological Brazilian census (2003 and 2010) it was observed a decline of tooth loss in teenagers and young adults; however, edentulism rates were still raising in the elderly as a result of the increase in life expectancy 4,15,16 . Likewise, it is projected that tooth loss will continue to be a major dental problem in the next decades, which might impair patients general health and cause disabilities 17 . Not only complete edentulism but a reduced number of teeth is directly related to quality of life worsening, since it can compromise daily activities, such as chewing, nutrition, phonation, social life, and self-esteem 18,19 .
Although dental implants are recognized as the gold standard approach to replace missing teeth 5,6 , Brazil is one of the few countries in the world that provides free dental implant rehabilitations in the public health system while some countries with higher human development indexes (HDI) do not fully cover such treatments. The costs involved in implant rehabilitations are among the key factors that are considered by patients when choosing their therapy. It is well-known that the vast majority of edentulous persons usually belong to the poorest population stratum and have difficult access to treatment with dental implants 20 . In Brazil, a single dental implant costs on average about 1,000-1,500 Brazilian reais (BRL), which is approximately 250 US dollars (USD). Considering that Brazil's minimum wage is about to 245 USD, the low-income population has no option than to rely on the public health system to obtain their rehabilitations. In a recent review, a single implant rehabilitation was a more cost-effective option compared to a three-unit fixed dental prosthesis to replace a single tooth 21 . Considering the rehabilitation of multiple teeth, dental implants were initially associated with higher initial costs; however, the patient-centered outcomes Continuation were improved during life-course compared to other treatment options. In this perspective, the present study presents important results about the coverage of implants placement in the National Health System. As above stated, although the costs could impact the coverage, the enhancement of dental implants in the SUS could represent a key factor to improve the oral health-related quality of life in the Brazilian population.
In 2016, a previous study showed that the access to dental implants at SUS was increasing until that moment, but the distribution was very unequal throughout the country 22 . Our findings update their data, and it is clear that there was an important increase from 2015 to 2016 and from 2016 to 2017 ( Figure 3). However, the following years showed a clear reduction in the total number of procedures of 30.7% in 2018 and 29.6% in 2019 compared to 2017. It is important to highlight that since 2014 Brazil is facing a serious economic crisis and that in 2016 the Brazilian government changed its priorities, with a cascade of budget cuts that surrogated the health investments in the following years which could explain the massive reduction of procedures during these years 23 .
Bueno et al. 24 evaluated the correlation between social and oral health determinants represented by the indicators of the National Oral Health Policy (Smiling Brazil) and found that, hierarchically, clusters with the best performance in social determinants and oral health outcomes were composed by the Brazilian Capitals, presenting the highest values of notification of procedures. Regions that presented high indexes of social determinants in the years 2000-2010 might have pioneered in the organization and availability of these procedures of medium complexity that, until then, were not offered by the public health system 24 . The organization and provision of health services are related to the human development of the macro-regions 25 and with this, the South and Southeast regions present higher rates of use of dental services, with a high number of specialized dental procedures. These findings are also observed in our study, where the South and Southeast regions were the regions that provided more dental implant treatments in the last decade while the North region, which presents the lowest social and economic indexes in Brazil, has also presented the lowest number of treatments regarding dental implants. It is important to highlight that the Brazilian government has public policies to reduce health inequities for the North and Northeast regions 23,25,26 ; however, those inequities are evident in our findings.
In order to provide information to support objective analyzes, evidence-based decision making, and the development of health action programs, SUS have created the Brazilian health information databank (DATASUS). This databank also allowed for decentralization and an improvement in the management of SUS activities, contributions, viability, usage of available resources, and it is constantly updated and discloses the information needed for health actions 13 . As funding is only available after the execution of the procedures and the corresponding input in the databank, the DATASUS tool can be considered a reliable tool for accounting and analysis of the services provided by SUS. However, according to a Technical Note from the Brazilian Ministry of Health 27 , non-conformities in outpatient production reported by some municipalities were identified, which would explain the high number of procedures performed in some locations. The processing of outpatient production in the SUS Outpatient Information System (SIA/SUS) is performed by the local manager, even when the services were provided by non-governmental companies, and therefore, those responsible were informed of the need to reimburse overpriced amounts. When data are not presented by the cities, it is assumed that the procedures were not carried out since the government's funding occurs only after the registration and reporting of the performed procedures. Consequently, eventual failures in the registration of procedures could underestimate the implants and prosthetic procedures. Thus, the misregistration and lack of data of some locations constitutes a limitation of the present study. However, it is our understanding that such limitation impact also the SUS management and planning and, therefore, specific actions should be made by SUS in order to secure that all cities provide the information to the database. Another important limitation of this study is the lack of sociodemographic data available in DATASUS, since the database does not provide access to patients' medical records, preventing access to data that would be important to our study, such as gender, age range of individuals, type of rehabilitation (unitary, partial or total), number of implants placed in each patient, and clinical aspects, such as the need of reintervention or clinical success. Regarding the type of the rehabilitation, it is important to highlight that SUS have only one general code for implant rehabilitations that does not define whether a single crown or a full-mouth rehabilitation was made. Thus, it is highly recommended that such code must be revised by SUS since the costs of each type of treatment present very different costs and specificities. In this way, we suggest that codes for implant-retained single crowns, implant-retained partial fixed dentures, overdentures and full-arch fixed rehabilitations could be adopted by the SUS.
The findings of this study suggest that the public policies adopted by SUS in the last decade are still far from providing the best treatment option to the population 9,10 . Recent papers by Hartmann et al. 28,29 have found that the incremental costs for fullarch fixed prosthesis compared to overdentures retained by a single implant is not proportional to the respective gain in effectiveness, and that simplified implant treatments for edentulous patients result in favourable outcomes. Considering that, we also suggest the standardization of overdentures retained by a single implant by SUS, considering that it would reduce the costs and provide high-quality services to the population. Finally, new policies and public actions should be made in order to provide this type of treatment for the Brazilian population.
In conclusion, although dental implant therapy is available in SUS across the country, the number of treatments provided in the last decade is still very limited and is also mainly concentrated in the southeastern region of Brazil.