Introduction

With the growing acknowledgment of health as a critical determinant of sustainable development, the stakeholders find themselves pressured to prioritize various underlying aspects. Oral health, especially teeth, lends itself to the subject as one of the areas that deserve attention. Indeed, statistics are documented and they affirm the problematic nature of the aspect. For instance, over 3.9 billion people across the world have oral health problems [1]. Tooth decay (dental caries) affects at least 44 percent of the global population, rendering it the most prevalent of all health conditions. It is estimated that at least 60 percent of the population of schoolchildren and 100 percent of adults across the world suffer from some level of tooth decay. The condition is often characterized by substantial discomfort and pain, in addition to eating and sleep disruption, chronic and acute infection, disfigurement, and reduced quality of life. It is also revealed that this health problem affects many other aspects of individual life, including self-esteem and sociability. Even more appalling, treating oral diseases, especially those affecting teeth, ranks fourth among the most expensive intervention processes in healthcare contexts. For example, at least US$110 billion in the United States is spent on oral care each year. In the European Union, annual health expenditure on oral health is over €79 billion, overshadowing the money spent on other troubling chronic conditions such as respiratory illnesses and cancer [1]. Overall, the problematic nature of the condition justifies the need to research evidence-based practices that would lessen the plight of affected patients. Calcium silicate presents itself as a new, potentially viable sealer, but its efficacy is yet to be effectively qualified. This paper conducts systematic research to ascertain the efficacy of calcium silicate-based sealers.

Literature review

The literature facing the subject is documented but it does not effectively resolve the underlying questions. Notwithstanding, it succeeds in providing the basis for conceptualizing the breadth of the topic while unearthing the controversies and gaps that help frame the underlying issues in a better way and justify the criticality of the research. Literature is laden with various themes that can be conveniently classified into three sections: nature of root canal treatment; types of sealers, merits and demerits; and conceptualizing cost-effectiveness/efficacy of the intervention.

Nature of root canal treatment procedure

The literature on root canal treatment describes it as a procedure with several steps that must be followed to deliver desired outcomes. Lokhande et al. (2019) particularly offer an elaborate description of the procedure, noting that the obturation begins with cleaning and removing all substrates from the canal [2]. This procedure is then followed by further sterilization and shaping the canal to create a logical cavity for effective filling. The canal is then filled with a biocompatible material. The overall process of filling and sealing the canal cavity aims at avoiding further infection and associated propagation, a process broadly referred to as the root call obturation. The creation of fluid-tight seals on the apical foramen, followed by obliteration of the pulp space with aim of preventing fluid percolation into the canal, is particularly a critical step in the obturation process. This process is also important because it creates an enabling biological environment for the healing of the periapical tissues. The overall success of the endodontic treatment is the obturation that creates a fluid-tight seal. On the other hand, poor obturation is often accompanied by apical leakage, entry of microorganisms, and toxins, which negate the essence of treatment. Leakages can be so costly that they may warrant tooth removal. According to Kikly et al. (2020), to prevent this problem, the obturation of the root canal should involve the use of an appropriate sealer [3]. Overall, this discussion presents root canal treatment as a demanding and delicate process in which great care must be taken at every stage. However, particular emphasis is placed on the sealing process, which implies that the choice of sealing agent matters a great deal.

Types of sealers, merits, and demerits

A plethora of literature also covers types of sealers, merits, and demerits. In a nutshell, the topic is progressive, evidenced by researches and discoveries of new sealing agents, for which their efficacy must be assessed to qualify their viability. More elaborate, Lim et al. (2020) note epoxy resin-based sealers are currently the most popular, with the AH Plus formula taken as the gold standard [4]. Notwithstanding, this agent has several weaknesses such as cytotoxicity, inflammatory responses, hydrophobicity, and mutagenicity. Because of these weaknesses, several other alternative sealants, especially calcium silicate-based sealers, have been sought because of their relative hydrophilicity and biocompatibility. Nevertheless, choosing a particular sealer to use is not always straightforward, as several factors need to be considered. For instance, considering the hydrophilic conditions of the root canals, water solubility, and resorption are critical parameters of their stability. Sealers that display reduced micro-leakage but elevated push-out bond strength must also be able to withstand dynamic tooth conditions. In essence, while calcium silicate-based sealers are promising candidates, their efficacy is yet to be rigorously studied. In the same vein, Jafari and Jafari (2017) acknowledge that new generations of endodontic sealers, especially those based on calcium silicate such as EndoSequence BC, iRoot SP, MTA-Angelus, MTA Fillapex, Total Fill BC, Endo CPM, ProRoot Endo sealers, have been developed [5]. They are advantageous because of flowability and film thickness, but their property of high solubility remains an issue of concern. To this end, the literature review highlights that, whereas the breakthroughs leading to novel discoveries of alternative sealants are worth celebrating, it is still too early to conclude whether calcium silicate-based sealers must fully replace the conventional sealers. The merits of new sealers are largely debatable. There is a need to conduct a follow-up study to determine its relative efficacy.

Conceptualizing cost-effectiveness/efficacy of sealants

 As can be inferred from the preceding section of the literature review, deducing the efficacy of a particular sealer is not simple, as several dimensions should be considered. Concerning efficacy, several concepts have been mentioned. These concepts include cytotoxicity, inflammatory responses, hydrophobicity, mutagenicity, hydrophilicity, biocompatibility, flowability, and film thickness [4, 5]. An objective conceptualization of these concepts creates an allowance to argue that, as far as efficacy is concerned, what particularly matters is the relative utility of a particular sealer judged from various conventional indicators of desired treatment outcomes, such as the ability to:

• Optimize health outcomes such as improved quality of life, reduced pain, and patient satisfaction with care;
• Minimize harm and risks of complications related to the procedure;
• Reduced costs of condition management in the short and long-term.

Aim of the study

The study aims to ascertain the efficacy of calcium silicate-based sealers and make related recommendations to practice. To accomplish this aim, several objectives are considered.

Objectives

• Does the use of calcium-silicate-based sealers result in quality care outcomes in patients in a randomized controlled trial compared to the alternatives?
• Does the use of calcium-silicate-based sealer procedure reduce the harm and risks of complications in patients in a randomized controlled trial compared to the alternatives?
• Does the use of calcium-silicate-based sealers have short and long-term cost-effectiveness in patients in randomized controlled trials compared to the alternatives?

Materials and Methods

The literature search was done online. The search strategy was guided by the objectives. The following pairs of keywords were used.

1. Calcium-silicate-based sealers, the impact of the quality of care outcomes, quality of life, reduced pain, patient satisfaction.
2. Calcium-silicate-based sealers, harm, risks, comparison.
3. Calcium-silicate-based sealers, cost-effectiveness, comparison.
4. Calcium-silicate-based sealers, efficacy, comparison.
5. Epoxy resin-based sealers, calcium-silicate-based sealers, comparison.

The search words were entered into search engines of Google and other websites such as Google Scholar, Biomedical Central, Science Direct, Pub Med, CINAHL, and Medline. The number of targeted articles was 100. It was anticipated that the search would yield many sources with different characteristics, some of which may diminish the validity and reliability of the research if considered for review. In this regard, the inclusion and exclusion criterion was developed to guide the process of identifying valid sources of information. It was centered on the following rules:

1. The included sources need to be peer-reviewed journals. Other common sources of information such as trade publications, magazines, blogs, and newspapers were not considered for review.
2. The articles should be reports arising out of primary research. Systematic reviews were excluded. The scope of designs was open to cover quantitative and qualitative studies. Theoretical discussions and general discussion sources such as books were excluded, too.
3. The articles of priority were full-text articles. Abstracts and summaries were excluded.
4. Sources of information published within the last five years (2016, 2017, 2018, 2019, and 2020) were prioritized. Articles published earlier than 2016 were excluded.

Cochrane risk of bias assessment

According to the Cochrane Risk of Bias Assessment Table (Appendix C), the chosen studies did not have performance bias/blinding (participants and personnel) and detection bias/ blinding (outcome assessment). However, all the studies had a low risk for attrition bias/ incomplete outcome data [6-14]. Additionally, concerning the selection biases like random sequence generation and allocation concealment, Table 1 indicates that the studies had low risk. The same low risk was also witnessed for reporting bias such as selective reporting.

Table 1. Cochrane Risk of Bias Assessment

Results and Discussion

Overall, the research generated 100 articles. However, 45 articles were found to be non-peer-reviewed and excluded. Out of the remaining 55, 20 articles were found to be report research arising out of second research such as systematic or Cochrane reviews. Therefore, they were excluded. A further evaluation revealed that out of the 25 remaining articles, 13 had been published before 2016. Upon exclusion on this basis, 11 articles were finally considered for review (Figure 1).

Table 2. Study findings