Is there consensus for the treatment of initial to moderate caries lesions? - a Delphi first-round study

Abstract

Background and aim

The effectiveness of evidence-based operative recommendations is often complicated by variations in study design and a lack of use of standardized or validated materials / operative techniques. These gaps in evidence can lead to confusion and hinder clinicians’ ability to apply guidelines in clinical practice. The objective of the presented paper is to compare the clinical recommendations from 17 experts regarding the management of early and moderate proximal and occlusal caries lesions.

Methods

This paper employs the Delphi methodology to evaluate the expert recommendations presented and compare them with existing EBD guidelines.

Results

This study highlights a clear hierarchy in the therapeutic choices made by experts. The highest compliance is seen with the initial, evidence-based treatment options, while responses diverge as more specific or novel options are introduced.

Conclusion

The variability in expert responses suggests a lack of clear and standardized guidelines for partially or non-cavitated lesions, a gap in EBD protocols that could benefit from further research and consensus-building.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12903-026-09441-w.

Introduction

Evidence-Based Dentistry (EBD) aims to help optimize clinical outcomes by following conclusions drawn from meta-analyses, clinical trials and other levels of evidence [1–3]. The effectiveness of evidence-based operative recommendations in Restorative Dentistry are often complicated by variations in study design and a lack of use of standardized or validated materials / operative techniques. These gaps in evidence can lead to confusion and hinder clinicians’ ability to apply guidelines in clinical practice. Moreover, expert opinions and the strength of evidence - whether weak, moderate, or strong - can vary, largely due to differences in available meta-analyses and the duration of commercial availability of certain products. Uncertainties persist within several critical areas, such as caries diagnostic tools, caries risk/susceptibility assessment, biomaterials, person-focused management approaches and clinical alternatives, particularly when EBD guidelines limit the adoption of newer techniques. This confusion is exacerbated by the varying degrees of certainty between the different levels of evidence, clinical reality and what is essentially an ‘experience-related’ estimate of effectiveness. The challenges are especially evident in more sensitive techniques, such as the management of early carious lesions with the use of resin infiltration in posterior teeth proximal surfaces or sealants with adhesive resin or flowable composites on proximal surfaces.

EBD recommendations should provide clear, actionable guidance for patients, practitioners and policymakers [4–7]. As an example, some clinicians remain skeptical about the benefits of optical aids with magnification, fearing that they may lead to over-treatment of disease [8]. As of March 2024, the Organization of Caries Research (ORCA) and the European Federation of Conservative Dentistry (EFCD) recommend visual examination as the primary method for detecting caries lesions on accessible surfaces [9–11]. They do not specifically endorse magnification tools such as cameras utilizing photonic signals [9–11]. For assessing lesion activity, the visual-tactile approach remains the preferred method, with no explicit recommendation for photonic signal aids [8]. Another area of confusion thanks to the different levels of evidence available and their interpretation, arises in the evaluation of caries risk/susceptibility [9–11]. This integrates various assessment methods such as the Caries Management by Risk Assessment (CAMBRA) [9–11], National University of Singapore Caries Risk Assessment (NUS CRA) [12, 13], the American Dental Association (ADA) [14] Caries Risk Assessment, Cariogram [15], along with Caries-risk Assessment Tool (CAT), Minimum Intervention Oral Care (MIOC) [16, 17] and CariesCare 4D best clinical practice approaches [18]. Despite their widespread use, these methods fail to reach a consensus within EBD guidelines [9–11]. This lack of consensus extends to the management of patients with occlusal or proximal caries lesions. The decision-making process is complicated by the need to consider factors such as caries susceptibility, patient behavioral adherence, lesion activity, presence of cavitation, lesion accessibility, biomaterial choice [19] and presumed prognosis [11, 20, 21]. For example, the initial phase of cleaning the carious lesion surface remains undefined in the current guidelines. Options include using an Air-polishing system with low-abrasive powder such as erythritol, versus a rotating brush with prophylactic paste [9, 11, 20]. Studies suggests that Air-polishing technology provides superior cleaning, particularly for occlusal or proximal lesions. It allows for the early detection of micro-cavitation that might otherwise be masked by prophylactic paste and remain undetectable to the naked eye, but visible via optical aids. This marks a significant shift in the treatment paradigm, as current therapeutic options for such lesions remain limited [9, 11, 22, 23]. Whilst treatments are clearly differentiated according to caries susceptibility during preventive and prophylactic stages, using non-invasive or micro-invasive strategies, this distinction becomes less clear during minimally invasive lesion management [17, 18].

The objective of this paper is to compare the clinical recommendations from 17 international experts regarding the management of early and moderate proximal and occlusal caries lesions. Using the Delphi methodology [24] and in part the PICO structure (Population, Intervention), the presented paper evaluates these expert recommendations and contrasts them with existing EBD guidelines [25].

Materials and methods

The Delphi method is a structured research technique designed to gather data from experts within a specific domain. It aims to address divergent opinions or controversial issues and achieve consensus on real-world knowledge regarding a particular topic. Widely used in medical education, the Delphi method has been applied to areas such as curriculum development and clinical procedures [26, 27]. In the present study, the Delphi process was employed to gather expert opinions on treatment options for early to moderate caries lesions (up to mICDAS 3) [28].

The process began with the identification and recruitment of qualified experts. A partial PICO (Patient/Population, Intervention) questionnaire was developed and sent to the selected experts to collect their responses (Round 1). The responses were then analyzed to identify areas of consensus and difference. The corresponding author outlined various treatment options, allowing the experts to suggest additional treatments or modifications. The results from this round were then compared with Evidence-Based Dentistry (EBD) treatment recommendations, based on the findings of relevant published systematic reviews. Inter-expert agreement was assessed separately for each of the 12 clinical scenarios using Cohen’s Kappa coefficient. For each scenario, the experts’ first-ranked treatment combinations were compared pairwise, and the mean Cohen’s Kappa value was calculated to provide an overall estimate of agreement while accounting for chance agreement. Only first-ranked treatment combinations were included in the inter-expert agreement analysis because they represented each expert’s preferred clinical decision. Each unique first-ranked treatment combination was treated as a distinct categorical response. Missing responses were excluded from pairwise comparisons.

In Round 1, experts were asked to propose up to three potential treatments for early caries lesions, ranked according to their clinical expertise and experience. The goal was to generate a prioritized list of possible treatments based on expert consensus. A second Delphi round had initially been planned if the first round suggested that controlled feedback could reasonably improve convergence among experts. After analysis of the Round 1 responses, the steering committee decided not to proceed with a second round. The observed heterogeneity was considered to reflect genuine differences in expert clinical reasoning rather than uncertainty or misunderstanding of the questionnaire. Consequently, additional voting was considered unlikely to substantially improve convergence between experts. As the primary objective of the study was to document current expert decision-making and compare it with existing Evidence-Based Dentistry (EBD) recommendations, the present work should be interpreted as a Delphi first-round expert elicitation rather than a formal Delphi consensus process.

Expert recruitment and inclusion criteria

Experts were purposively selected based on their recognized scientific and/or clinical expertise in cariology, minimally invasive dentistry, restorative dentistry or dental biomaterials. The panel included university academics, clinician-researchers and experienced private practitioners from several European countries and Australia, thereby ensuring diversity of clinical backgrounds and perspectives. The purpose of this heterogeneous recruitment strategy was to capture a broad spectrum of contemporary expert opinion rather than represent a statistically representative sample of clinicians. Some expert clinical propositions should therefore be interpreted as exploratory suggestions rather than treatments ready for routine clinical implementation.

Expert treatments considered for initial proximal lesions

Expert clinical propositions for initial proximal lesions in Table 1.

Table 1.

Treatments considered for proximal lesions (Figs. 1 and 2)

Population

Intervention

INITIAL PROXIMAL LESIONS Patients with permanent teeth and initial proximal surface carious lesions requiring management (Figs. 1 and 2). Four clinical cases: 1. Proximal initial lesion without cavitation with a Low Caries Risk/Susceptibility (LCR). 2. Proximal initial lesion without cavitation with a High Caries Risk/Susceptibility (HCR). 3. Proximal initial lesion with cavitation restricted to enamel and a LCR. 4. Proximal initial lesion with cavitation restricted to enamel and a HCR.

A: Active surveillance and caries preventive therapy (oral hygiene information, use of fluoride toothpaste, instruction and recommendations, diet control, MIOC recommendations). B: Airflow cleaning using erythritol or soft sodium bicarbonate with tooth separation to gain visual access. C: Fluoride varnish. D: Resin infiltration (ICON, DMG, Germany). E: Silver diammine fluoride (SDF). F: Self-Assembling Peptides (Curodont™ Repair, vVardis, Switzerland). G: Combination of SDF + resin infiltration. H: Combination of Self-assembling peptides P11-4 + resin infiltration. I: Drilling. J: Other treatments: additional methods suggested by experts based on clinical experience or exploratory expert suggestions. Treatment A was deemed as a useful initial phase and was applicable to all 12 clinical cases.

Fig. 1.

a, b Radiograph of a carious lesion scoring a E1/RA1 – b E2/RA2

Fig. 2.

Radiograph of a carious lesion scoring D1/RA3

Expert treatments considered for initial occlusal lesions

Expert clinical propositions for occlusal proximal lesions in Table 2.

Table 2.

Treatments considered for occlusal lesions (Fig. 3)

Population

Intervention

INITIAL OCCLUSAL LESIONS : Patients with permanent teeth and initial occlusal carious lesions requiring treatment. Four clinical cases: 1. Occlusal initial lesion without cavitation, LCR. (Fig. 3). 2. Occlusal initial lesion without cavitation, HCR (Fig. 3). 3. Occlusal initial lesion, cavitation restricted to enamel, LCR. 4. Occlusal initial lesion, cavitation restricted to enamel, HCR. Figure 3 ICDAS 1, 2

A: Active surveillance and caries preventive therapies (Oral hygiene information, use of adapted fluoride toothpaste, instruction and recommendations, dietary control, CPP-ACP tray application, MIOC recommendations). B: Airflow cleaning using soft powder such as erythritol or soft sodium bicarbonate. C: Fluoride varnish. D: Resin sealant or flowable mineral-enriched resin composite. E: Flowable glass-ionomer cement (Flow GIC fissure sealant) or high-viscosity GIC (HVGIC) using finger press technique. F: SDF. G: SDF + sealant. H: Self-assembling peptides. I: Self-assembling peptides + sealant. J: Drilling with a micro-bur. K: Airflow using bioactive glass to open the fissure. L: Other treatments, additional methods suggested by experts based on clinical experience or exploratory expert suggestions.

Fig. 3.

ICDAS 1, 2

Expert treatments considered for proximal surface moderate lesions with initial cavitation

Expert clinical propositions for moderate proximal lesions with initial cavitation in Table 3.

Table 3.

Treatments considered for proximal surface moderate lesions with initial cavitation (Fig. 4)

Population

Intervention

Proximal surface moderate lesions with initial cavitation: Patients with permanent teeth and moderate carious defects requiring management (Fig. 4). Two clinical cases: 1. Proximal lesion with initial cavitation (mICDAS 3), LCR. 2. Proximal lesion with initial cavitation (mICDAS 3), HCR. Figure 4D2/RB4. Radiolucency extends into the middle third of the dentine.

A: Active surveillance and caries preventive therapies (Oral hygiene information, use of adapted fluoride toothpaste, instruction and recommendations, dietary control, CPP-ACP tray application, MIOC recommendations). B: Airflow cleaning using soft powder such as erythritol or sodium bicarbonate. C: Fluoride varnish. D: Slot preparation (+ GIC). E: Tunnel preparation (+ GIC + resin composite or mineral-enriched composites: MEC). F: SDF. G: Dentine disinfection (Chlorhexidine or other). H: Enzymatic conditioning (papain-based systems). I: High-viscosity GIC - HVGIC only. J: Resin composite proximal class II restoration. K: Resin composite proximal class II restoration. K: GIC + resin composite, layered restoration. L: Other treatments, additional methods suggested by experts based on clinical experience or exploratory expert suggestions.

Fig. 4.

D2/RB4. Radiolucency extends into the middle third of the dentine

Expert treatments considered for moderate occlusal lesions with initial cavitation

Expert clinical propositions for moderate occlusal lesions with initial cavitation in Table 4.

Table 4.

Treatments considered for moderate occlusal lesions with initial cavitation

Population

Intervention

Moderate Occlusal Lesions with Initial Cavitation: Patients with permanent teeth and moderate carious defects requiring treatment. Two clinical cases 1. Occlusal lesion with initial cavitation, LCR. 2. Occlusal lesion with initial cavitation, HCR.

A: Active surveillance and caries preventive therapies (Oral hygiene information, use of adapted fluoride toothpaste, instruction and recommendations, dietary control, CPP-ACP tray application, MIOC recommendations. B: Airflow cleaning using soft powder (erythritol or sodium bicarbonate). C: Airflow cleaning using bioactive glasses to gain access to the dentine lesion. D: Resin composite. E: GIC. F: SDF + GIC. G: SDF + resin composite. H: Enzymatic conditioning. I: Other treatments, additional methods suggested by experts based on clinical experience or exploratory expert suggestions

Evidence base guidelines for initial / moderate occlusal and proximal lesions

The table of treatments based solely on the EBD guidelines also takes into account the levels of certainty and recommendations [4–6, 29].

Populations: EB treatments of initial proximal lesions

EBD recommends four treatment options (A, B, C, D): A: Active surveillance and caries preventive therapies (Oral hygiene information, use of adapted fluoride toothpaste, instruction and recommendations, dietary control, CPP-ACP tray application, MIOC concept recommendations). Thes steps are common to all population. B: Fluoride varnish. C: Resin infiltration. D: SDF. (Table 5).

Table 5.

EB guidelines for initial proximal lesions

Population	Intervention
Proximal initial lesion without cavitation, LCR.	B: Fluoride varnish alone, C: resin infiltration alone, C.
Proximal initial lesion without cavitation, HCR.	B: Fluoride varnish alone, C: resin infiltration alone.
Proximal initial lesion, cavitation restricted to enamel, LCR.	D: 38% SDF.
Proximal initial lesion, cavitation restricted to enamel, HCR.	D: 38% SDF.

Certainty and recommendations: The certainty of the recommendations is very low, and they are conditional

Precisions

There is a notable absence of recommendations regarding cleaning protocols, detection/diagnostic tools and the selection of products based on caries susceptibility or lesion activity due to a lack of evidence of the highest level (a suitably designed and powered randomized controlled clinical trial). Evidence-based guidelines suggest the use of sealants in proximal areas, although they do not specify the precise clinical techniques or procedures, as these methods are highly technique sensitive. Resin infiltration is generally recommended for patients at high caries risk/susceptibility [30]. Additionally, the proposed use of self-assembling peptide (P11-4) system has not yet been fully validated in clinical practice [31, 32]. Furthermore, minimally invasive procedures, such as the slot or tunnel technique preparation, are not addressed in the literature, with a disproportionate focus on proximal surface preparations [11].

Populations: EB treatments of initial occlusal lesions

Evidence Based Dentistry recommends four treatment options (A, C, D, E). A: Active surveillance and caries preventive therapies (Oral hygiene information, use of adapted fluoride toothpaste, instruction and recommendations, dietary control, CPP-ACP tray application, MIOC concept recommendations). Thess steps are common to all population. C: 38% SDF. D: Resin sealants composite materials. E: GIC, applied using the finger press technique. (Table 6).

Table 6.

EB guidelines for initial occlusal lesions

Population	Intervention
Initial occlusal lesion without cavitation with LCR.	Sealant alone (D, E) or combined with fluoride varnish.
Initial occlusal lesion without cavitation with HCR.	Sealant alone (D, E) or combined with fluoride varnish.
Initial occlusal lesion, cavitation restricted to enamel with LCR.	38% SDF(C) or sealant alone (D, E).
Initial occlusal lesion, cavitation restricted to enamel with HCR.	38% SDF (C) or sealant alone (D, E).

Certainty and recommendations: The certainty of the recommendations is very low, and they are conditional

Precisions

A primary concern is that EBD does not prioritize the classification of cavitation in clinical management proposals as outlined in the ICDAS classification [33–35]. Specifically, recommendations include placing a sealant on a non-cavitated lesion, while offering SDF treatment for cavitated lesions, without combining both approaches [6]. In cases where treatment seems impossible, solutions such as 5% NaF varnish, 1.23% APF gel, or 0.2% NaF mouth rinse may be proposed as alternatives. Regarding restorative techniques, EBD struggles to balance the use of glass-ionomer cement (GIC) and resin composite and does not give clear recommendations between low viscosity GIC and HVGIC as ad hoc materials for the finger press technique. Additionally, EBD classifies lesions as either cavitated or non-cavitated, without distinguishing cavitated lesions limited to the enamel (depth ranging from 0.1 mm to 0.5 mm), which are difficult to diagnose and treat due to limited accessibility, unless there is direct access to the lesion.

Population: EB treatment for proximal moderate lesions with shallow cavitation [5, 6]

EBD provides two treatment options (A, J), compared to the 13 options recommended by experts. A: Active surveillance and caries preventive therapy, including tooth brushing education, dietary recommendations, and the MIOC concept are common to all population. J: Class II preparation. (Table 7).

Table 7.

EBD guidelines for moderate proximal lesions with shallow cavitation

Population	Intervention
Proximal lesion with shallow cavitation with LCR.	J: Class II preparation with dental amalgam, resin composite, or resin-modified GIC.
Proximal lesion with shallow cavitation with HCR.	J: Class II preparation with dental amalgam, resin composite, or resin-modified GIC.

Certainty and recommendations: The certainty of the recommendations is very low, and they are conditional.

Precisions

The use of amalgam has been prohibited in Europe since 2025, in accordance with the Minamata Convention. However, EBD experts do not address the use of HVGIC light cure, HV self-cured products, or newer generations of mineral-enhanced composites (MEC), such as Stela (SDI, Australia) and Activa Bioactive Restorative (Pulpdent, USA) [21] even according the caries susceptibility of the patient. A significant issue is that the EBD response is overly simplistic, as it categorizes lesions as “cavitated” without considering the various dimensions and shapes of cavitation, which can significantly impact pragmatic, clinical treatment decisions.

Population: EB treatment of moderate occlusal lesions with shallow cavitation

EBD provides two treatment options (A, D). A: Active surveillance and caries preventive therapy, including tooth brushing education, dietary recommendations, and the MIOC concept are common to all population. D: occlusal restoration. (Table 8).

Table 8.

EB guidelines for moderate occlusal lesions with shallow cavitation

Population	Intervention
Occlusal lesion with shallow cavitation with LCR.	D: Conventional GIC, dental amalgam, resin composite, or resin-modified GIC or compomer.
Occlusal lesion with shallow cavitation with HCR.	D: Conventional GIC, dental amalgam, resin composite, or resin-modified GIC or compomer.

Certainty and recommendations

The certainty of the recommendations is very low, and they are conditional.

Precisions

Evidence Based Dentistry does not specify in detail whether the materials and techniques should vary based on a patient’s caries susceptibility, except during the individual prophylaxis phase. For further details, refer to the MIOC recommendations [36, 37]. Additionally, while dental amalgam use will be phased down in 2025, EBD experts fail to address the use of HVGIC light cure, hybrid HVGIC, high-viscosity self-cured products, or newer generations of mineral-enriched composites (MEC), such as Stela (SDI, Australia) or Activa Bioactive Restorative (Pulpdent, USA) [21]. On the other hand, EBD recommendations include selective carious tissue excavation but does not clearly discuss the option of carious lesion arrest with bioactive materials like GICs [21].

Statistical analysis

Three complementary analyses were performed. First, descriptive inter-expert concordance was assessed by calculating the proportion of experts selecting identical treatment options for each clinical scenario and for each response rank (Ranks 1, 2 and 3). This analysis describes the distribution of expert preferences without implying consensus. Second, agreement with current Evidence-Based Dentistry (EBD) recommendations was evaluated by calculating the percentage of expert responses corresponding to treatment options supported by published EBD guidelines. Compliance was classified as non-compliant (no EBD-supported response), poorly compliant (≤ 5%), moderately compliant (> 5% to ≤ 20%), or highly compliant (> 20%). Third, inter-expert agreement was assessed separately for each of the 12 clinical scenarios using the mean pairwise Cohen’s Kappa coefficient. For each clinical scenario, the experts’ first-ranked treatment combinations were compared pairwise, and the mean Cohen’s Kappa coefficient was calculated to provide an overall estimate of agreement beyond chance. Only first-ranked treatment combinations were included in the inter-expert agreement analysis because they represented each expert’s preferred clinical decision. Each unique first-ranked treatment combination was treated as a distinct categorical response. Missing responses were excluded from pairwise comparisons. Kappa values were interpreted according to the Landis and Koch classification: <0.00 poor agreement; 0.00–0.20 slight agreement; 0.21–0.40 fair agreement; 0.41–0.60 moderate agreement; 0.61–0.80 substantial agreement; and 0.81–1.00 almost perfect agreement.

Results

A clear distinction has been made with 3 specific chapter Inter-Expert concordance / Percentage agreement with EBD and Inter-Expert Consistency: Cohen’s Kappa Index. The analysis included 159 Rank 1 responses, of which 12 identified as EBD. Rank 2 had 98 responses, with only 2 corresponding to EBD recommendations. Rank 3 had 46 responses, none matching EBD. These results indicate that while evidence-based choices predominated in first-line responses, there was less consistency in second- and third-order responses. This reflects a hierarchy in therapeutic certainty and highlights limitations in achieving uniform decision-making across experts (Table 9).

Table 9.

Experts concordance rate for IPLWC: Initial proximal lesion without cavitation. IPLCRE: Initial proximal lesion, cavitation restricted to enamel, LCR/HCR. (Table 1)

Population/Clinical situations	Answer rank	Common answer per rank	(%) Decrease maximum concordance rate per rank	Number of experts concerned per rank
IPLWC LCR	1	A	33.3	5
IPLWC HCR	1	A + C	26.7	4
IPLCRE LCR	1/2/3	A + E /A + C/ A + D	20.0 /13.3/13.3	3/2/2
IPLCRE HCR	1/1/2/3	A + E/ A + B+D/ A + B+D/ A + B+H	20.0/13.3/13.3/13.3	3/2/2/2

Legends. A: Active surveillance and caries preventive therapies. B: Air-polishing step C: Fluoride varnish. D: Resin infiltration. E: SDF. H: Self-assembling peptides + resin infiltration

Experts concordance rate of initial proximal lesion

Precisions

The percentages of agreement between experts, which were initially low, decreased from 33.3% to 13.3% and remained stable through the second rank of responses (Table 1). Only two experts applied Self-assembling peptides for IPLWC LCR (Table 10).

Table 10.

Expert concordance rate of IOLWC: Initial occlusal lesion without cavitation. IOLCRE: Initial occlusal lesion, cavitation restricted to enamel, LCR/HCR

Population/Clinical situations	Answer rank	Common answer per rank	(%) Decrease maximum concordance rate per rank	Number of experts concerned per rank
IOLWC LCR	1/1/2	A/A + B+C/ A + B+F	26.7 /20.0/13.3	4/3 /2
IOLWC HCR	1/1/2/2	A + C+D/ A + B+D/ A + B+D/ A + E	20.0/13.3/13.3/13.3	3/2/2/2
IOLCRE LCR	1/1/1	A + B+D/ A + D/ A + K+E	26.7/13.3/13.3	4/2/2
IOLCRE HCR	1/1/2	A + B+D/ A + K+E/ A + B+E + C	20.0/13.3/13.3	3/2/2

Legends. A: Active surveillance and preventive therapies. B: Air-polishing cleaning using soft powders. C: Fluoride varnish. D: Resin sealant or flowable mineral-enriched resin composite. E: Flow GIC or HVGIC with finger pressure technique. F: SDF. K: Air-polishing with bioactive glass to open the fissure

Experts concordance rate of initial occlusal lesion

Precisions

The percentages of agreement between experts, which were already low, decreased further from 26.7% to 13.3% and remained stable through the second and third ranks of responses. Experts also introduced the use of airflow with bioactive glass for cavity preparation, the press finger technique, and the use of new mineral-enriched resin composites.(Tables 2 and 11).

Table 11.

Concordance rate of PLSC: Proximal lesion with shallow cavitation, LCR /HCR

Population/Clinical situations	Answer rank	Common answer per rank	(%) Decrease maximum concordance rate per rank	Number of experts concerned per rank
PLSC LCR	1/1/2/3	A + B+D/A + D/A + B+J /A + B+E	13.3/13.3/13.3/13.3	2/2/2/2
PLSC HCR	1/1	A + J/ A + B+D	13.3/13.3	2/2

Legends. A: Active surveillance and preventive therapies. B: Air-polishing cleaning using soft powders. D: Slot preparation (+ GIC). E: Tunnel preparation (+ GIC + resin composite or mineral-enriched composite). J: Resin proximal Class II restoration

Experts concordance proximal moderate lesions with shallow cavitation

Precisions

The percentages of agreement between experts remained low up to the third rank of responses, showing little variation. Experts introduced the possibility of slot or tunnel cavity preparation. (Tables 3 and 12).

Table 12.

Concordance rate of OLSC: Occlusal lesion with shallow cavitation LCR/HCR

Population/Clinical situations	Answer rank	Common answer per rank	(%) Decrease maximum concordance rate per rank	Number of experts concerned per rank
OLSC LCR	1/1/1/2/2	A + D/A + B+D/ A + C+D/A + E/ A + C+G	20.0/20.0/13.3/13.3/13.3	2/3/3/2/2
OLSC HCR	1/1/2/2	A + D/A + B+D/ A + B+F/ A + B+E	20.0/13.3/13.3/13.3	2/3/2/2

Legends. A: Active surveillance and preventive therapies B: Air-polishing using soft powders (e.g., erythritol or Na bicarbonate) C: Air-polishing cleaning using bioactive glass (BAG) to open the carious lesion cavity. D: Resin composite. E: GIC. G: SDF as dentine conditioning + resin composite. F: SDF + GIC

Experts concordance rate of occlusal moderate lesion with shallow cavitation

The percentages of agreement between experts decreased from 20.0% to 13.3% through the second rank of responses. Experts introduced the combination of silver diammine fluoride (SDF) with GIC or resin composite, as well as the use of bioactive glass powder for cavity preparation. (Table 4).

Percentage agreement of expert responses to the eb treatment propositions

Each clinical situation was evaluated based on the total number of expert responses received, the presence of therapeutic proposals aligned with EBD recommendations, and the percentage of responses that adhered to these guidelines. A qualitative compliance ranking was established using the following thresholds (Table 13).

Table 13.

Cut-off percentage of expert agreement to the EBD

Compliance	% of agreement
Non-compliant	No EBD-based response
Poorly compliant	≤ 5% agreement to EBD responses
Moderately compliant	> 5% and ≤ 20% agreement
Highly compliant	> 20% agreement

Agreement of expert responses to the EB treatment proposition for initial proximal lesions

Compliance remains moderate (> 5%) to low (≤ 5%) for the treatment of initial proximal lesions without cavitation. Notably, experts have strongly recommended the use of Air-polishing with soft powder as a cleaning step to improve accessibility and diagnostic accuracy. Notably, no expert recommended treatments based on sealants or resin adhesive for proximal lesions (Fig. 5).

Fig. 5.

IPLWC: Experts agreements for initial Proximal lesion without cavitation. IPLCRE: Initial proximal lesion, cavitation restricted to enamel. A: Active surveillance and caries preventive therapy (oral hygiene guidance, dietary control, MIOC recommendations). C: Fluoride varnish. D: Resin infiltration. E: SDF. Average dotted linear curve variation of the agreement values

Percentage agreement of expert responses to the EB treatment proposition for initial occlusal lesions

Compliance remains low (≤ 5%) to moderate (> 5%) for the treatment of initial occlusal lesions without cavitation. As mentioned previously, the Air-polishing phase is missing, which could be useful for managing occlusal lesions. Furthermore, some experts have proposed alternative treatments, such as SDF or self-assembling peptides personally (Fig. 6).

Fig. 6.

IOLCRE: Experts agreement for initial occlusal lesion, cavitation restricted to enamel. IOLCRE : Experts agreement for initial occlusal lesion, without cavitation. A: Active surveillance and preventive therapy (oral hygiene guidance, dietary control, MIOC recommendations). C: Fluoride varnish. D: Resin composite sealant. E: GIC using press finger technique. Average dotted linear curve variation of the agreement values

Percentage agreement of expert responses to the EB treatment proposition of proximal moderate lesions with shallow cavitation [5, 6]

Compliance for the treatment of proximal surface shallow cavitation lesions remains poor. The optional Air-polishing cleaning phase is not included. Some experts suggested alternative treatments such as slot and tunnel cavity preparations, as well as the specific use of bioactive dental materials, depending on caries risk/susceptibility assessment. Notably, EBD does not differentiate clearly between the indications for resin composite, GIC or amalgam [38, 39] (Fig. 7).

Fig. 7.

PLSC: Experts’ agreements for proximal lesion with shallow cavitation; LCR/HCR. A: Active surveillance and caries preventive therapy (oral hygiene guidance, dietary control, MIOC recommendations, conditioning). J: Resin composite proximal Class II restoration. Average dotted linear curve variation of the agreement values

Percentage agreement of expert responses to the EB treatment of moderate occlusal lesions with shallow cavitation

Agreement on the treatment of occlusal shallow cavitated lesions remains poor. Again, the optional Air-polishing phase is not included. Some experts suggested using bioactive dental materials, depending on caries risk/susceptibility assessment and considered combining them with SDF. EBD does not clearly differentiate the indication between resin composite, GIC and amalgam according the individual’s caries susceptibility [40] (Fig. 8).

Fig. 8.

OLSC: Experts agreements for occlusal lesion with shallow cavitation; LCR/HCR. A: Active surveillance and caries preventive therapy (oral hygiene guidance, dietary control, MIOC recommendations). D: Occlusal restoration. Average dotted linear curve variation of the agreement values

Compliance for treating occlusal shallow cavitated lesions remains poor to moderate in the case of LCR. Some experts recommended specific bioactive dental materials, depending on caries susceptibility assessment and whether they were combined with SDF.

Inter-expert agreement (pairwise mean Cohen’s Kappa)

This analysis employed the Cohen’s Kappa Index to assess inter-expert agreement across the 12 clinical situations. Unlike simple agreement counts, the Kappa Index adjusts for chance agreement, providing a more reliable measure of concordance (Table 14).

Table 14.

Kappa values interpretation

Compliance	Kappa values and interpretations
< 0.00	Poor agreement
0.00–0.20	Very low agreement
0.21–0.40	Low agreement
0.41–0.60	Moderate agreement
0.61–0.80	Good agreement

Treatment of initial proximal lesions

Compliance for Proximal Initial Lesions without Cavitation (PILWC) and PILCRE (Initial Proximal Lesion, Cavitation Restricted to Enamel) were below 0.2, indicating very low consistency, whilst one result above 0.2 showed low consistency (IPLWC LCR). Linear curves described the agreement variations (Fig. 9).

Fig. 9.

PILWC: Inter-expert coherence for proximal initial lesion without cavitation. PILCRE: Proximal Initial lesion cavitation restricted to enamel and average agreement between experts. Average dotted linear curves of the variation values

Treatments for initial occlusal lesions

Compliance for Initial Occlusal Lesions without Cavitation (IOLWC) and IOLCRE (Initial Occlusal Lesion, Cavitation Restricted to Enamel): One clinical scenario, specifically an initial occlusal lesion without cavitation (LCR), had a Kappa value exceeding 0.25, indicating low agreement. Average linear curve of the variation values (Fig. 10).

Fig. 10.

IOLWC.: Inter-expert coherence for initial Occlusal lesion without cavitation. IOLCRE: Initial occlusal lesion, cavitation restricted to enamel and average agreement between experts. Average dotted linear curves of the variation values

Treatment of proximal moderate lesions with shallow cavitation [5, 6]

Compliance for Proximal Moderate Lesions with Shallow Cavitation. None of the proposed treatments exceeded the 0.2 threshold, indicating minimal consistency. Average linear curve of the variation values (Fig. 11).

Fig. 11.

PLSC: Inter-expert coherence for proximal lesion with shallow cavitation, LCR/HCR and average agreement between experts Average dotted linear curves of the variation values

Treatment of moderate occlusal lesions with shallow cavitation

Compliance for Moderate Occlusal Lesions with Shallow Cavitation. Similarly, none of the proposed treatments exceeded the 0.2 threshold, indicating minimal consistency, except for occlusal lesions with shallow cavitation (LCR). Dotted linear curves described the agreement variations, and patient caries risk reduced the agreement values (Fig. 12).

Fig. 12.

OLSC: Inter-expert coherence for occlusal lesion with shallow cavitation, LCR/HCR and average agreement between experts. Average dotted linear curves of the variation values

Final recommendations: integrating EB guideline and expert clinical knowledge

These recommendations combine evidence-based practices (EBP) with insights from minimally invasive dentistry and biomaterials experts. While these suggestions may face scrutiny, they offer potential treatment strategies that EBD’s limitations overlook, thereby improving clinical care over time. Active surveillance and caries preventive therapies, as outlined in the best-practice MIOC delivery approach, along with the use of air-polishing with soft powder for cleaning during pre-operative steps, may be considered as useful procedures for all the clinical situations described, such as the use of so-called bio-interactive materials in case of high caries risk/susceptibility. It should be noted that the proposed new cleaning protocol, involving air-polishing and tooth separation in daily practice, for all treatments, suggests practice-ready standards; however, the certainty of the supporting evidence remains low even that remains the experts preferred option. For the proposed treatments different option were described : preferred treatment when diagnostic certainty and clinical feasibility are high; acceptable alternatives when evidence is uncertain but the clinical rationale is plausible and situations where an intervention should be avoided (Non-invasive).

Propositions of possible treatments of initial proximal lesions

1. Initial proximal lesion without cavitation (LCR): Non-invasive treatment.

• Self-assembling peptides + Fluoride varnish or Remineralising agents.

• 2.Initial proximal initial lesion without cavitation (HCR): Non-invasive treatment.

• Self-assembling peptides + Fluoride varnish or Remineralising agents.

• SDF. (Preferred option)

1. Initial proximal initial lesion with cavitation restricted to enamel (LCR): Micro-invasive treatment.

• Resin infiltration / sealing or SDF combined with Fluoride varnish or Remineralising agents. (Acceptable alternatives)

• 2.Initial proximal initial lesion with cavitation restricted to enamel (HCR): Micro-invasive treatment.

• Resin infiltration / sealing or SDF, combined with Fluoride varnish or Remineralising agents. (Acceptable alternatives)

Propositions of possible treatments for initial occlusal lesions

1. Initial occlusal lesion without cavitation (LCR): Non invasive treatment.

• Remineralising agents or SDF. (Sealant application remains the preferred treatments according the shape of the occlusal fissures).

• 2.Initial occlusal initial lesion without cavitation (HCR): Micro-invasive treatment.

• Fluoride varnish or Remineralising agents or Resin sealant, or flow mineral-enriched composite, or Flow GIC (fissure sealant) or HVGIC with finger press technique. Optional: SDF application before finger press technique. (Preferred treatments).

• 3.Initial occlusal lesion with cavitation restricted to enamel (LCR): Micro-invasive treatment.

• Resin sealant, flowable mineral-enriched composite, or Flow GIC(fissure sealant) or HVGIC with finger press technique, or Air-polishing with bioactive glass to open the fissure and resin or GIC. (Preferred treatments).

• 4.Initial occlusal lesion with cavitation restricted to enamel (HCR): Micro-invasive treatment.

• Resin sealant, flowable mineral-enriched composite or Flow GIC (fissure sealant) or HVGIC with finger press technique, or Air-polishing with bioactive glass to open the fissure and resin or GIC. (Preferred treatment, optional: SDF application before finger press technique).

Propositions of possible treatments for moderate proximal lesions with shallow cavitation. Invasive treatment [5, 6].

1. With shallow cavitation, LCR:

• Slot preparation (with GIC) or Tunnel preparation (with GIC + resin composite or Mineral Enriched Composite). (acceptable alternatives).

• Resin composite proximal class II restoration. (Not preferred treatment).

• 2.With shallow cavitation, HCR:

• Slot preparation (with GIC) option Tunnel preparation (with GIC + resin composite or Mineral Enriched Composite): (acceptable alternatives patient compliance needed).

• Resin Proximal class II restoration with a preference for HVGIC in case of high caries risk. (Preferred treatment).

Propositions of possible treatments for moderate occlusal lesions with shallow cavitation. Invasive treatment

1. Occlusal lesion with shallow cavitation, LCR:

• Resin composite.

• 2.Occlusal lesion with shallow cavitation, HCR:

• Resin composite or mineral enriched composite. ((acceptable alternatives patient compliance needed).

• GIC, SDF + GIC, SDF + HVGIC. (Preferred treatments).

Discussion

These findings should be interpreted with caution. Although the expert panel consisted of internationally recognized clinicians and specialists in biomaterials, cariology, and operative dentistry, its members came from diverse geographic regions and academic institutions. A relatively large panel was therefore selected to account for the expected variability in responses, since the conclusions of a Delphi study depend strongly on the composition, expertise, and independence of the participating experts. Experts, with their own limits, gathered specialist in biomaterials, in minimally invasive dentistry, in pediatric, a general practionner and few assistant professors. This study identifies a clear hierarchy in experts’ therapeutic choices. Agreement was greatest for first-line, evidence-based options, whereas responses became increasingly divergent when more specific, innovative, or less established treatments were considered. This variability suggests that standardized guidance remains insufficient for partially cavitated and non-cavitated lesions. It also highlights the need for stronger evidence, broader consensus, and more consistent clinical decision-making frameworks in Operative Dentistry. Although several emerging materials, techniques, and treatment combinations are not yet fully incorporated into EBD recommendations, they may be clinically relevant in selected patient contexts and should therefore be further evaluated rather than dismissed. The diversity of expert responses further supports the need for validated protocols to guide decision-making in common clinical situations. These findings emphasize the importance of greater standardization, particularly through evidence-based decision pathways. The limited alignment with EBD beyond first-line choices also raises questions about how scientific recommendations are disseminated and integrated into continuing education and daily practice. Delphi panels and other consensus methods may help structure expert judgement across clinical scenarios. Ultimately, robust protocols should combine EBD recommendations, clinical feasibility, and patient needs or preferences.

This study has several limitations. First, only the first Delphi round was completed. Although classical Delphi methodology generally includes iterative rounds with controlled feedback to increase convergence, the present study was intentionally designed to capture the diversity of expert clinical reasoning before any influence of group feedback. The marked heterogeneity observed after the first round suggested genuine differences in clinical judgement rather than ambiguity in the questionnaire. Consequently, the results should be interpreted as describing current expert opinion rather than a formal Delphi consensus. Additional Delphi rounds might have increased convergence between experts, although whether this would have reflected genuine consensus or merely greater alignment of opinions remains uncertain.

Second, the expert panel included clinicians and academics from different countries and professional backgrounds. While this diversity strengthens the external validity of the findings, it may also have contributed to the observed variability in treatment recommendations.

Accordingly, the present study should be interpreted as a first-round Delphi expert elicitation describing current expert opinion rather than as a completed Delphi consensus process. The main challenge remains identifying the most appropriate treatment in situations where expert consensus is weak or evidence is limited. Many proposed options lack broad agreement but are still considered because alternatives are limited. Complex restorative techniques with uncertain outcomes may be difficult to implement in general practice; for example, Japanese guidelines excluded resin infiltration because it is not widely used in clinics and is not covered by national health insurance [41]. Finally, apart from prophylactic and preventive measures that account for caries susceptibility, few recommendations specifically tailor materials or treatments to individual caries risk [11, 17, 42]. Clinicians generally tend to adopt more invasive approaches when caries susceptibility is high. In this study, expert concordance, agreement with EBD treatment proposals, and mean Cohen’s kappa values were used to assess inter-expert coherence across 12 clinical scenarios. Agreement was generally low to very low. This heterogeneity was interpreted as reflecting genuine differences in expert clinical judgement rather than uncertainty regarding the questionnaire, and therefore was not considered likely to be substantially reduced by an additional Delphi round. Although the broader range of expert-proposed treatments, compared with EBD recommendations, may have introduced some uncertainty, it also expanded the spectrum of clinically plausible options. For initial proximal caries lesions, resin infiltration appears promising for non-cavitated lesions. However, several clinical questions remain unresolved: should it be proposed for all patients or mainly for selected groups, such as those with high caries risk? Can proximal surfaces be adequately cleaned without tooth separation? How can non-cavitation be reliably confirmed when early defects are visible only with optical aids? How should infiltration depth and optimal light activation be controlled? Finally, does resin infiltration provide any additional benefit compared with sealing using a resin adhesive [43]? Is combining techniques such as SDF and resin infiltration feasible? We lack long-term clinical data on these technique sensitive methods in case of high caries risk/susceptibility patients [29, 44]. These questions are the same for the application of self-assembling peptides [45–47]. For moderate lesions, expert recommendations differed from EBD guidance, with minimally invasive slot or tunnel preparations favored over conventional Class II restorations. However, when proximal lesions in permanent teeth are cavitated or extend into dentine, operative intervention is required, as non-invasive and micro-invasive approaches are unlikely to be effective [29]. The use of minimally invasive approaches, such as slot or tunnel preparations, for carious lesion management remains poorly documented. Although technique-sensitive and dependent on specific equipment, these methods provide, while preserving the marginal crest, an intermediate treatment option before resorting to more conventional and invasive preparations [20, 22, 48, 49]. However, this requires the general dental practitioner to have and be able to use, specific technologies such as sonic or ultrasonic diamond inserts and powerful optical aids [9, 20, 22]. For initial occlusal caries lesions without cavitation, experts and EBD concurred better, but concerning occlusal lesions limited to enamel, in addition to the authors’ precisions, the real clinical questions are - should we just clean and seal? Are we allowed to open the fissure with a bioglass (Sylc™ powder) coupled with the air flow? Can we combine GIC and SDF application [50]? Should we use flowable GIC specifically in case of high susceptibility patient or high viscosity GIC? Is rubber dam isolation mandatory?

Conclusions

Success in treatment is deeply tied to patient behavioral adherence, making the person-focused, prevention-based, susceptibility-related and team-delivered holistic minimum intervention oral care approach essential. EBD should serve as a guide for reflection rather than a rigid mandate, as each patient and lesion present unique challenges. With the ever-increasing reliance on clinical guidance and protocols within the profession, omitting the use of modern technologies and materials may deprive practitioners of effective treatments that could enhance clinical outcomes [16, 38]. Moreover, EBD’s “all-or-nothing” approach to cavitation is insufficient for cases of partial or minimal cavitation, highlighting the need for ongoing professional development and research. The results show substantial variation in therapeutic choices, despite some initial convergence around validated approaches. This finding reflects the lack of clear benchmarks for partially cavitated or non-cavitated lesions and underscores the need for stronger continuing education in evidence-based practice. The variability in expert responses also supports the development of standardized, validated protocols to guide common clinical decisions in dentistry. However, innovation should not be dismissed simply because EBD validation requires time and may not always translate into immediate clinical value. A key limitation of this study is the difficulty of clearly identifying treatments that are strictly validated by EBD, which may have introduced bias into the comparison framework. Overall, the diversity of expert opinions supports a more open integration of EBD and clinical expertise to improve quality of care.

Abbreviations

BAG

Bioactive Glass

GIC

Glass-ionomer cement /HVGIC: high-viscosity glass-ionomer cement

EBD

Evidence-based dentistry

EB

Evidence based

HCR

High risk/susceptibility of caries

LCR

Low risk/susceptibility of caries

MIOC

Minimum Intervention Oral Care

MEC

Mineral-enriched composite

SDF

Silver diamine fluoride

Authors’ contributions

Conceptualization: H.T.; writing-original draft: A.S. and H.T.; Writing-Review and editing: A.S., S.S., B.A., D.M, H.T., L.S.T. Delphi survey: T.H, B.A, L.S.T, M.I, C.R, P.T, P.V, T.E, T.D, S.S, J.B, G.S., M.M, S.D, B.B, M.D, S.A.; Statistical analysis: D.T.

Funding

This research received no external funding.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study is inherently non-interventional, devoid of any direct observations or clinical interventions. It does not involve patients, nor does it include procedures such as biopsies. All expert participation was on a voluntary basis. Consequently, under the provisions of the French Jardé legislation, this study did not require approval by an ethics committee (https://www.legifrance.gouv.fr/jorf/id/JORFTEXT000025441587).

All experts agreed on the substance and form, adhere to the Declaration of Helsinki and international ethical standards, and have informed consent and agreed to participate in this non-patient study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.