Introduction
Dental caries is one of the most prevalent diseases with a reported global estimate of 29.4% affecting more than 2.3 billion people worldwide [
1,
2]. It can progress to involve the pulp where a part of it may become incapable of self-repair thus, resulting in irreversible pulpitis [
3]. The diagnosis, however, may not reflect the actual histological status of the pulp as it is assumed based on clinical symptoms and crude diagnostic tools [
4]. Conventionally, irreversible pulpitis has been treated with pulpectomy as it is a predictable approach [
5,
6].
Evidence-based histological studies have shown that in teeth with irreversible pulpitis, the microbial invasion is limited to just the coronal portion with the absence of inflammation in the radicular pulp [
7]. The emerging insights in pulp biology have led to a better understanding of the disease process [
8‐
10]. In this regard, pulpotomy has emerged as a potential alternative to root canal therapy for the management of irreversible pulpitis in mature permanent teeth [
11]. It has the advantage of maintaining pulp vitality, thus retaining its physiological and defensive functions. Secondly, it is a conservative procedure resulting in less weakening of tooth structure [
12].
In the routine management of irreversible pulpitis in mature permanent teeth, dentists are faced with the dilemma of deciding between pulpotomy and root canal treatment. Although the latter has been associated with more predictable outcomes, dental practitioners may wish to adopt a biologically driven treatment approach, thereby attempting to maintain pulpal health [
11]. Moreover, the costs for both therapies vary, with pulpotomy being less costly initially compared to root canal treatment, however, to the best of our knowledge, the utility of this modality in terms of being cost-effective eventually, in the long run, is yet to be established [
13].
When healthcare providers are confronted with a difficult clinical situation, health economics evaluation in the form of a cost-effectiveness analysis can be a pragmatic approach that helps in effective decision-making for the functional allocation of resources [
14]. One approach to health economics evaluation is analytic modeling, where the input data can be retrieved from previously published clinical studies [
15]. In this regard, we applied the realistic economic model guided by cost and outcome parameters from the relevant literature to evaluate the cost-effectiveness of pulpotomy versus root canal treatment in mature permanent teeth with irreversible pulpitis. Our aim was to test the hypothesis that whether pulpotomy which is less costly at face value was associated with improved health outcomes in terms of life years gained by a tooth over a period of lifetime of an individual.
The operational definition of various terminologies used in this paper related to health economics is presented in Supplementary Table
1.
Discussion
Irreversible pulpitis in mature permanent teeth has been routinely managed with root canal treatment as it is reliable, having a success rate of 95–99% [
5,
6]. In an era of minimally invasive dentistry, dental practitioners are more inclined towards procedures that preserve the vitality of pulp [
23]. Traditionally, pulpotomy was carried out using calcium hydroxide, which has now been superseded by a more biological material like Mineral Trioxide Aggregate (MTA), with a success rate of up to 95% [
13,
24]. Despite this high success rate, pulpotomy may fail resulting in necrosis and periapical pathosis [
13]. Consequently, teeth may require follow up intervention thereby accruing costs in the long term. Thus, in difficult clinical situations, where dental practitioners might have to choose between two interventions, a cost-effectiveness analysis can play a pivotal role as this aids in effective decision making allowing for the functional allocation of resources.
Cost-utility analysis and cost-effectiveness analysis are the two common types of economic evaluation used to evaluate the cost-effectiveness of a certain intervention. Cost-utility analysis reports the qualitative as well quantitative outcomes in the form of a single measure such as Quality Adjusted Life Years (QALYs). From our perspective it may not be an appropriate tool as it considers the utility values derived from various healthcare indices that do not detect the true impact of oral conditions [
25]. For instance, the most widely used index is the EuroQol (EQ-5D-5 L) tool that evaluates five different attributes (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) associated with the quality of life of an individual [
26]. This concept was further modified, and Quality Adjusted Tooth Years (QATYs) and Quality Adjusted Prostheses Years (QAPYs) were introduced however, they have not developed much over the years [
27].
Cost-effectiveness analysis has been extensively studied in dentistry and is the widely used tool to assess the cost-effectiveness of certain intervention in the context of a specific healthcare setting [
28]. It compares the cost and effectiveness of different interventions based on a shared outcome measure (such as retention of tooth or reduction in DMFT index etc.) [
29]. In this regard, we developed a Markov simulation model from the private payer perspective in the context of United States (US) health care to follow mature permanent teeth with irreversible pulpitis receiving either pulpotomy or root canal therapy, based on the best available evidence.
The findings of our study suggested that root canal treatment was associated with marginally increased health benefits in terms of number of years a tooth was retained in the oral cavity (1.08 more years) and at the expense of increased cost. In contrast, pulpotomy was associated with reduced health benefits as well as reduced cost. Moreover, to maximize the yield of the model, a lifetime horizon was chosen. This was possible with the incorporation of the function of hazards per cycle that takes into account the adverse events over the longest follow-up period available from literature and then predicts the incidence of adverse events over the entire life course [
30].
Some previous studies in dentistry have utilized a similar model to evaluate the cost-effectiveness of direct pulp capping compared to root canal treatment following vital pulp exposures [
31,
32]. A study conducted on the Scandinavian population concluded that direct pulp capping was more cost-effective compared to root canal treatment in children and adolescents [
31]. Likewise, a study on German population reported direct pulp capping to be more effective in younger patients and for occlusal exposure sites whereas root canal treatment was more cost-effective in older patients and teeth with proximal exposures [
32]. However, in our study the effect of exposure site as well as the influence of age factor was not analyzed.
Given that the findings are in the context of United States healthcare, one may have concern that our results are not adequately generalizable. This is the inherent limitation of a cost-effectiveness analysis as they could only be as good as the data in the published studies which may be biased in some way or the other. However, to address the uncertainties in model inputs and to quantify the level of confidence in the output, a probabilistic sensitivity analysis was used. Therefore, considering the robustness of our model, the outcome is unlikely to be affected under different testing conditions.
The results of the probabilistic sensitivity analysis revealed the majority of ICERs in the North-East quadrant representing increased cost and increased effectiveness for root canal treatment compared to pulpotomy. This is where a trade-off comes into play in such cases, and it is the Willingness-to-Pay (WTP) threshold that decides whether the intervention is cost-effective or not. Moreover, in the US a WTP threshold of USD 50,000 per Life Year gained for an individual is referenced by the researchers however, there is no established consensus on the WTP threshold value for a tooth’s LY gained. Hence in our analysis, the probability of the cost-effectiveness of pulpotomy and root canal treatment was plotted against a range of arbitrary WTP values to determine their acceptability at different values. At lower WTP values, pulpotomy turned out to be a cost-effective treatment option whereas at increased WTP threshold values, root canal treatment was more cost-effective. Owing to the comparable effectiveness of both interventions in terms of life years gained by a tooth, this has considerable implications for healthcare professionals as well as policy makers particularly in areas where there are financial constraints, enabling them to choose between pulpotomy and root canal treatment in the management of irreversible pulpitis in mature permanent teeth.
Having said that, our analysis had certain limitations. Owing to the lack of primary data, the opportunity cost of patients’ time in treatment as well as that of the healthcare providers was not taken into consideration. Moreover, the effect of etiological factors (i.e., caries, trauma, or any developmental anomaly), the exposure site (i.e., occlusal, proximal, etc.) as well as patient related factors on the success probability of individual modalities, was not accounted for. Lastly, when pulpotomy fails and root canal treatment is performed, there is a risk of canal calcification. Since these risks and potential complications of future root canal treatment have not been evaluated in endodontic literature, therefore it was not considered in this study.
Conclusion
In the context of United States healthcare, pulpotomy was an acceptable treatment option in terms of cost-effectiveness at lower WTP values for the management of irreversible pulpitis in mature permanent teeth. However, by increasing the WTP threshold, root canal treatment became a more acceptable treatment option over a period of lifetime of an individual.
Future directions
Applying a societal perspective includes a broad spectrum of public benefits, however, restricting it to the insurer perspective was primarily due to the lack of primary data surrounding the indirect costs involved. Therefore, it is an important limitation of our study, and the authors recommend future research on identifying cost drivers necessary to measure the indirect costs in this area. Moreover, since there is scarce evidence regarding the WTP threshold for a tooth’s LY gained, future research work should also be directed to explore this undiscovered domain.
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