Cost minimization and financial impact of root canal therapy techniques : manual , rotary and reciprocating

The root canal therapy consists of phases aimed at cleaning and disinfection of the root canal system. The chemomechanical preparation is the one that makes use of instruments that can be used by means of mechanized techniques (rotary and reciprocation) and manual. The present study seeks to compare the three instrumentation techniques, based on cost and outcome, using the cost – minimization analysis in the perspective of the Social Service of Commerce (SESC Brazil), and a time horizon of 10 years. The effectiveness of the techniques were raised through literature review and selection of systematic review studies. The costs were measured by the microcosting technique, in addition to the information from the SESC databases. In the analyzed period, the study shows that the use of the rotary system can increase the capacity of care by 44,67%, while the reciprocation system by 168 %. The financial impact would be R$ 103,683.87 and R$ 735,179.46 for the rotary and reciprocation, respectively. Using as reference the conventional technique, R$ 44.58 more is spent for the treatment with rotary instruments and R$ 84,03 for the reciprocation. Even with the highest allocating efficiency for the reciprocating technique with much greater coverage, the budget impact needs to be analyzed with caution. The incorporation of reciprocating technology demonstrating to be the technique with the highest allocating efficiency, best minimization cost ratio and reasonable cost of additional treatment in relation to other techniques.


Introduction
The basis of endodontic therapy consists of treating teeth compromised by pulp and periapical pathologies, so that the patient can recover his natural aesthetics and function. It consists of a sequence of procedures that typically include four phases: instrumentation or mechanical preparation, irrigation, medication, and filling. Success is dependent on the prevention or elimination of apical periodontitis and patient symptoms (Chubb, 2019;Chugal et al, 2017).
The European Society of Endodontics, in its document: Guidelines for the Quality of Endodontic Treatment (Lost, 2006), states that the purpose of mechanical preparation is to remove the remains of pulp tissue, eliminate microorganisms, remove debris and shape the channels so that the root canal system (RCS) can be cleaned and filled. The desired shape is conical with the bottleneck in the crown-apex direction. Alongside with irrigation, the chemomechanical preparation (CMP) is the most important phase of endodontic treatment, since it acts on the formatting and disinfection of the RCS (Siqueira et al, 2017).
For the satisfactory preparation of the root canal, instruments that penetrate its interior are needed and, with correct movements and irrigators, promote its cleaning. Currently, traditional manual instruments, made of stainless steel, coexist with more flexible instruments, made of titanium nickel alloys (NiTi), which allow their use in equipment that promotes mechanized instrumentation. There are two types of mechanized kinematics that use nickel instrumentstitanium: continuous rotation or centric rotation, called "rotation" and alternative rotation, oscillatory which is called "reciprocator" (Gavini et al, 2018).
The rotary instruments produce fast preparations, with adequate centralization and taper and lower failure rate. However, these are subject to fractures due to their continuous movement (Peralta et al, 2019). Yared (2008) proposed the use of a unique NiTi rotary file in the preparation of the root canal using, for this, an engine that promoted the movement of 120º clockwise and 30º in the opposite direction. A lower fracture rate was observed, in addition to shorter treatment time and good efficacy in endodontic preparation. In 2010, VDW (VDW, Munich, Germany) launched a system based on reciprocation movement, where the instrument is manufactured with a new NiTi alloy, M-Wire, which receives a heat treatment, providing greater flexibility and resistance to cyclic fatigue compared to Development, v. 9, n. 11, e46291110119, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.10119 conventional alloy (Gutmann & Gao, 2012). The objective of the reciprocation instrumentation system is the usage of a single instrument in the preparation of the root canal, speeding up this phase, reducing cyclic fatigue and the chance of cross-contamination (Yared, 2008).
Numerous studies have focused on the effectiveness of manual instrumentation in the disinfection of RCS, often comparing with automated systems. The results obtained did not show significant differences (Oliveira & Oliveira, 2011;Matos et al, 2012;Del et al, 2018).
For mechanized systems, in two systematic reviews, Siddique & Nivedhitha (2019) and Neelakantan et al. (2019) presented the best available current evidence, suggesting similarity between rotary and reciprocating systems with regard to bacterial disinfection and reduction of endotoxins. However, they reinforced the need for more studies with the latest instruments. The Health Technology Assessment (ATS) is a systematic process, which aims to identify and evaluate the available scientific evidence on a given technology. The source of these studies in ATS verifies the effectiveness/efficiency, the costs of incorporating and disseminating certain technology, the consequences of disincorporation, as well as the ethical and legal implications arising from this decision. Therefore, it is up to the manager to make the decision to implement a new technology, taking into account the willingness to pay for it, based on mathematical modeling and designed according to the Economic Evaluation Guidelines of the Brazilian Health Technology Assessment Network (Vianna et al, 2009). This is particularly important because 616.481 endodontics were performed in 2019 in Brazil and thus knowing the efficiency of these techniques in terms of costs and effects are crucial Research, Society and Development, v. 9, n. 11, e46291110119, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.10119 6 for decision-making, especially in this period of economic recession that we are going through (in Brazil for some years).
In view of the above, it is intended to perform a complete economic evaluation (cost minimization analysis), with the calculation of allocating efficiency (number of procedures in the time horizon and ICER by additional treatment) and the budgetary impact of three techniques for the mechanical preparation of the RCS, the manual, the rotary and the reciprocation, from the perspective of the Social Service of Commerce (SESC -Brazil).

Methodology
This study was submitted to analysis by the Research Ethics Committee (CEP) of FOP/UNICAMP and dismissed for using secondary data (letter CEP no. 004/2020).
It is an economic study, with a synthesis methodology in which costs are confronted with clinical outcomes were objective is to assess the impact of different alternatives, which aim to identify them with better treatment effects, generally, in exchange for lower cost (Brasil, 2014). The design of this research was based on a complete economic analysis in oral health of the cost-minimization type (MCA) due to the similar results of effectiveness It is important to note that economic health assessments (AES) are not clinical studies, so we must make it clear that AES values health outcomes, providing a technology efficiency data, that is, verifying the cost in relation to the effect. All data are based on parameters obtained in the literature or from primary studies and, therefore, models are constructed and not statistical analyzes to compare groups of studies or seek association of variables. Therefore, we follow the Rebrats / Ministry of Health guidelines for Budget Impact Studies The perspective of analysis adopted was that of the SESC, starting initially from the data of the dental clinic of SESC Casa Amarela -PE/Brazil and aligning with other information from other units. The database was designed in view of the phases and sessions necessary for each endodontic technique employed. The information was obtained from the SESC registration system, taking into account the initial pulp vitality and the average number of sessions required for root canal therapy, based on the 2018 records. For the initial diagnosis, pulp vitality was considered, being divided into pulpitis (with vitality) and pulp necrosis (without vitality). There was no record of any periapical disease that made root canal therapy unfeasible. It is important to inform that SESC offers oral health services through 236 fixed and mobile clinics and is located in all regions of Brazil. For all phases consisting from the initial consultation to the end of the treatment, the inputs were assigned, whether it's in regards to equipment, instruments, consumables and human resources, necessary for the conclusion of each stage with its respective proportion to the quantitative spent for that phase. For digital acquisition equipment, the averages of the Research, Society and Development, v. 9, n. 11, e46291110119, 2020 (CC BY 4

Results
The entire microcosting technique was based on direct medical costs (human resources, materials, instruments, equipment). Table 1 shows the average of sessions required for each treatment in a referential tooth of three conduits, considering pulp vitality. Most   Taking into account the sensitivity analysis (

Discussion
The interest in the economic evaluation of health programs should be extended to all those who participate in the work processes of the area, from individuals to policymakers, through local managers of both public and private entities. Thus, some requirements should be followed, such as the definition of the intervention, the perspective of analysis, the possible alternatives, the identification and measurement of costs and the consequences on health.
Among the possibilities of complete economic analyses, it is possible to employ cost minimization analysis, in which the effectiveness of the comparative interventions is considered similar, and the cost examination is the main component studied (Brasil, 2014). files, found safety in the use of such instruments in 5 different root canals. Bueno et al. (2017) found safety in the usage of the same reciprocating instrument in 3 different posterior teeth.
(Peralta et al, 2019; Yared, 2008), (Guelzow et al, 2005;Vaudt etal, 2009 We make it clear that although the value of the reciprocating technique is lower, if it is used in its allocating fullness, it will cause a budgetary impact due mainly to the greater number of treatments performed. In any case, it seems obvious to us that the manager should take a decision based on the cost-to-budget ratio. In the event of creating possible scenarios, such as using the reciprocating instrument in 3 or 4 endodontics, this would make the budget impact much smaller with substantially greater coverage. In addition to the characteristics already pointed out, it is imperative for the manager to gather other information that can assist in the decision to incorporate. As already seen, the number of sessions has an important impact on the final cost and the agility acquired with the use of mechanized systems can contribute to the performance of a single session in both types of pathologies evaluated here, corroborating Almeida et al. (2017), who state that in clinical Research, Society and Development, v. 9, n. 11, e46291110119, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.10119 16 dentistry the biological criteria, professional skill, patient comfort and optimization of time and resources should guide the decision of the dentist.
It is necessary to reinforce that root canal therapy requires other phases besides instrumentation. Despite all technological development in the sector, there is still no instrument that can meet all the requirements of an optimal preparation of the root canal (Gavini et al, 2018). This fact highlights the importance of choosing a good irrigator and a filling that promotes three-dimensional sealing of the RCS. It is also important to point out that the three systems are safe alternatives for root canal preparation, however, no system is an absolute substitute for manual instrumentation.
The authors declare that there are no conflicts of interests.

Conclusion
The incorporation of reciprocating technology for SESC/Brazil perspective meets its general guidelines, demonstrating to be the technique with the highest allocating efficiency, best minimization cost ratio and reasonable cost of additional treatment (ICER) in in relation to other techniques.