1 Background

In the present scenario, dental caries have emerged as a significant health issue [1]. They appear due to bioacid formation in the oral cavity, which is responsible for the chemical dissolution of the enamel [2,3,4]. It is considered as demolition of the cementum, enamel, and dentin [2]. Identifying patients with higher and lower caries risk is essential for better, cost-effective, and specified reliable treatment. The patients having exposure to low caries risk must receive lesser dental examinations followed by reduced interventions.

In contrast, the patients exposed to the higher caries risk require higher interventions and examinations with intense awareness for their oral health. Routine dental examinations are required for such overexposed patients, along with the visual examination of the previous caries risk [3]. Generally, for assessing risk bias in dental health, recurrence of the previous caries is adequate. Also, radiography is being preferred to increase the accuracy and efficacy of the treatment. Microbiological examinations are also preferred to investigate the presence of lactobacilli and mutants of streptococci. Few other parameters such as buffer capacity, oral hygiene, salivary flow, and carbohydrate intake frequency, including socio-demographic aspects, also play a vital role in the appearance of dental caries [3]. For modern dental examinations against caries, a cardiogram has also emerged as a valuable treatment in practice. The heterogeneous results of caries risk management indicate variations with misinterpreting risk of clinical values for caries management [3]. A caries risk assessment system helps in identifying the fact that information collected on a large number of facts is comparatively lesser from the aspects of reported cases [4]. Several systematic reviews are conducted to summarize the assessment in health research. To study the complexity of available diagnostic tools, different review methods are developed. QUADAS and QUADAS-2 are widely used methods [5] that work on all the facts associated with caries [6]. To overcome other drawbacks of systematic review, PRISMA and AMSTAR are used [7, 8]. The present meta-analysis endeavors to analyze the methods studied for diagnostic accuracy of dental caries reported in the last 50 years, under different study designs exploring all the reported parameters. It provides cumulative details of caries risk management.

PICO Question: What are the necessary treatment and interventions against dental caries? Including the disease exposure, altered treatment, etiology, patient–parent perspectives, and the risk factors.

2 Main text

In the present review, we conducted the study according to the CRD’s guideline and PRISMA guidelines [8, 9].

2.1 Literature mining

To achieve this, a literature search was conducted in four (4) different databases such as PubMed, Web of science, OVID, and Cochrane library. It was conducted from March 19 to March 28, 2021. The search was conducted to answer the POIC question raised from keywords such as dental caries + specificity + selectivity + diagnostic methods + microbiodata. The articles downloaded after the searches were those that covered the topic between the period of January 1960 and December 2020 (Table 1).

Table 1 Literature mining

2.2 Inclusion criteria

In the present review, the randomized clinical trials, cohort studies, clinical trials, and cross-sectional studies were included. During our search, we focused on the risk assessment, treatment, and education-based articles on dental caries, including the management of risk factors (Table 2).

Table 2 Inclusion and exclusion criteria

2.3 Exclusion criteria

In this study, it was excluded the articles that dealt with a review of the literature on dental caries and the articles published before the year 1960. It was also excluded the articles that dealt with some factors responsible for dental caries such as smoking, illiteracy of parents, and alcohol consumption (Table 2).

Based on the selected search criteria, a total of 6387 articles were identified from the designed keywords. A total of 3387 articles were filtered after eliminating duplicates. Based on the defined exclusion criteria and the double filtering of articles, 19 articles were finally included in this review (Fig. 1). The included articles and their findings are listed in Table 3, and the risk assessment is presented in Table 4.

Fig. 1
figure 1

PRISMA chart

Table 3 Cochrane risk assessment table defining the assessment questions
Table 4 Summary of methods and conclusions of the articles included in this meta-analysis

2.4 Publication reclamation

The authors thoroughly studied all the abstracts and articles. The articles discussing the present issue were thoroughly analyzed under CRD’s guidelines [9]. We followed the search based on PRISMA guidelines (Fig. 1); the Cochrane risk assessment method was used for risk of bias assessment. In the present study, Cochrane, the risk assessment tool, was used based on seven questions. The questions are presented in Table 3, and they are based on selection bias, allocation bias, detection bias, attrition bias, reporting bias, performance bias, and other biases. The articles were analyzed based on their quality and were marked positive, negative, and unclear (Table 3).

3 Conclusions

The present meta-analysis attempts to summarize all the articles published in the last 50 years on the treatment and management of dental caries. Among extracted 6387 articles, only 19 articles were included in the study based on different yields and treatments available for existing dental caries in practice. All the articles are summarized as follows.

3.1 Study characteristics

The different studies used for this meta-analysis formed groups with the study population to achieve the objectives. This is the case, for example, of the work of Innes et al. [13] who divided their study into three groups, whereas Pine et al. [14] conducted their study on caregivers with DR-BNI and parents here; in DR-BNI groups, the parents received guidance from the trained nurses. In 2019, Jamieson et al. [15] studied 448 mothers and caregivers of children up to 5 years (Table 3). Milgrom et al. [16] also divided their study into two groups with and without dental lesions. Similarly, Arrow and Klobas [17] divided their study into two groups with and without Early Childhood Caries (ECC). Rest studies were conducted on the total sample size.

3.2 Characteristics for interventions of dental caries

Among all the included studies, 56% were based on preventive treatments for dental caries. Treatment was used against dental caries and pain management by Tickle et al. [18], da Silva et al. [19], Fernando et al. [20]; Milgrom et al. [16]; Frese et al. [12], Megalaa et al. [21] and Mathur et al. [22] reported use of 5000 ppm fluoride treatment, HVGIC, CPP-ACP and SNF2, 38% silver diamine fluoride, stannous fluoride, tulsi and myrobalans, ECC and Hu, CBCT, and IPT, respectively. They found these drugs effective against caries treatment.

3.3 Risk assessment analysis

In the article published by Innes et al. [13], the sample size was not precise, and reporting bias was unclear with low research quality (Table 4); in the study published by Pine et al. [14], unclear reporting and performance bias were analyzed. No detection bias was seen in the study published by Santos et al. [23], but a high allocation risk was found. In the study reported by Jamieson et al. [15], unclear reporting and performance bias were analyzed with risk of selection, allocation, and detection bias. In the article published by Heima et al. [24], we analyzed the low risk of attrition bias and other bias, with unclear results on performance bias. Unclear detection bias was seen in the article with a high risk of selection bias [10]. Unclear detection bias was seen in the article, with a high risk of selection bias (Alkarimi et al. [25]). The article published by Kopycka-Kedzierawski and Billings [26] was analyzed with high performance and selection bias. High selection and detection bias was seen in the article published by Stafuzza et al. [27], Mathur et al. [22], da Silva et al. [19], Tickle et al. [18], Milgrom et al. [16], Fernando et al. [20], Megalaa et al. [21] and Frese et al. [12], and these articles were categorized by us with low bias risk of attrition bias with unclear reporting bias.

All the included articles are based on diagnostic techniques for caries and their preventions. In the present study, we included 19 out of 6387 articles, which were further filtered for duplicate, and a total of 3887 articles was included in the study. After keen analysis and screening, we included 19 articles in the study. These articles were based on caries prevention. A similar review published by Senneby et al. [28] included eight articles in their study with poor study methodology. Prados-Privado et al. [29] conducted a systematic review to diagnose dental caries and detect their neural connection. They included 13 articles in their study and used Cochrane risk assessment for analysis. A different neural detection and connection were identified in every study; hence, they concluded that comparing the neural network and dental caries is also essential (Table 5).

Table 5 Risk bias assessment of the screened articles according to Cochrane risk assessment tool

In the present study, all the included articles are randomized controlled trials except two. The article published by Jordon et al. [30] was a cohort study, whereas Peterson et al. [11] was a clinical trial. Innes et al. [13] designed a randomized controlled trial and divided their study subjects into three groups. Group 1 was solely based on caries prevention, group 2 on biological management of caries, and group 3 on presentational and conventional caries management. They found an equal risk of caries in all the patients. In another article based on RCT, 241 children were included falling in the age group of 5 to 7 years. In this RCT, the participants were divided into two groups. Group 1 (BNI group) was the group under the supervision of trained nurses, and the participants in group 2 were solely based on the conversation between the parents and nurses. In this study, 29% low caries risk was seen in the BNI group [14]. Another study on children aged 8–10 years reported dental pains and their relationship with caries [23]. In a study published in 2019, 448 mothers and caregivers and their children were included in the study [15]. A similar study based on caretakers' behavior reported the importance of consciousness of the caretakers for children in reducing their dental caries [24]. The article published by Liu et al. [10] on 2376 elderly Chinese people reported more dental caries in the Chinese population; this can be due to their socio-demographic condition and high smoking habits. Alkarimi et al. [25] reported a co-relation of dental caries with appetite. They claimed cured caries could increase the appetite in young children.

Similarly, another study reported on socio-demographic conditions was published by Kopycka-Kedzierawski and Billings [26] where 234 children were included in the study and 28% of them had a history of dental caries, while another 61% of the study subject never had caries, and they found that routine checkups and awareness can avoid the chances of appearance of caries. Stafuzza et al. [26] reported their study on 36 patients with caries and concluded that early caries removal could reduce the chances of caries in the appearance of new caries. Jordan et al. [30] reported that more caries in childhood can cause high caries risk in older ages. Different kinds of comparative studies showed that awareness of oral health in parents and caretakers is critical. Furthermore, studies are required from the aspect of treatment of dental caries and pain management.

The present meta-analysis was a literature search of the articles published in different databases. Based on the designed keywords and the inclusion and exclusion criteria, 19 articles were included in this study after careful reading. The methodology studied by the authors was transparent except for a few. We conducted risk bias analysis and found Frese et al. [12], Liu et al. [10], and Innes et al. [13], where the articles can be ranged as high quality with low bias risk. Stannous fluoride emerged as a more proper treatment for the prevention of dental caries.

The study based on the effect of smoking in elderly adults by checking the anxiety level of the participants was found as a significant cause of the appearance of caries in older adults, whereas in children awareness of parents toward the oral health played an essential role in caries prevention. Previous caries history plays a pivot role for risk caries management to provide better treatment and caries prevention. New emerging techniques are also advancing dental care and oral health. The method with high accuracy and low risk can be recommended for routine treatment. Yet more advanced methods are required for caries detection in people of different ages.