Clinical and radiographic success of single-cone bioceramic obturation versus traditional techniques: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background

Bioceramic sealers, known for their bioactivity and biocompatibility, offer a promising alternative to traditional resin-based sealers. However, clinical evaluations are lacking. This systematic review and meta-analysis compared the clinical and radiographic outcomes of bioceramic single-cone obturation with those of conventional treatment and sealers.

Methods

We conducted a systematic search of PubMed, ScienceDirect, and the Cochrane Library for randomized controlled trials (RCTs) published up to March 2024. Our review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD420250212604). Included studies compared bioceramic single-cone obturation with conventional obturation in permanent teeth with a follow-up of ≥6 months. Risk of bias was assessed using the second version of the Cochrane Risk of Bias tool (RoB 2.0). A random-effects meta-analysis was performed to calculate pooled success rates, odds ratios (ORs), and 95 % confidence intervals (CIs). Heterogeneity and publication bias were assessed via I² statistics and Egger's test.

Results

Three RCTs involving 259 participants met inclusion criteria. The success rates for the bioceramic group were 88.7 %, 87.1 %, and 92.0 % at 6, 12, and 18 months, respectively, while those for the controls were 76.4 %, 76.4 %, and 90.7 %, respectively. Three studies reported higher success rates in the bioceramic groups than in the controls, although between-group differences were not statistically significant (overall OR range 1.12–2.09; p > 0.05). We observed moderate heterogeneity at the early follow-ups and negligible heterogeneity at the 18-month follow-ups.

Conclusion

Single-cone obturation with bioceramic sealers may result in small but clinically relevant advantages; however, more high-quality RCTs with longer-term follow-up are needed.

1. Introduction

Root canal therapy is a crucial procedure in dentistry that aims to eliminate infections from the pulp chamber while preserving natural teeth. The enduring success of root canal therapy depends not only on thorough biomechanical preparation and disinfection but also on the obturation quality. Achieving a three-dimensional seal that prevents bacterial reentry is essential for promoting periapical healing and maintaining the integrity of treated teeth.¹ Traditionally, obturation has been performed using gutta-percha cones along with various sealers to fill the intricate anatomy of the root canal system. Sealers such as zinc oxide eugenol (ZOE), calcium hydroxide, and epoxy resin-based materials such as AH Plus have been widely used for decades because of their favorable handling characteristics, effective sealing capabilities, and established clinical reliability.2, 3, 4 Nonetheless, issues such as shrinkage during setting, cytotoxicity, solubility, and lack of bioactivity have prompted researchers and clinicians to seek alternative materials that could overcome these limitations.⁵

Recently, root canal sealers have become widely used. While earlier materials, such as ZOE, offer some antimicrobial efficacy and ease of application, they do not adhere or provide solubility over time, which directly affects their long-term success. The introduction of epoxy resin-based sealers such as AH Plus provided even greater medicinal properties, including improved biocompatibility, radiopacity, sealing ability, and dimensional stability; however, they are limited by toxicity issues and lack of bioactivity. The most recent generation of sealers, bioceramics, has completely changed the direction of sealers into cutting-edge materials, with a new paradigm shift toward bioactivity, hydrophilicity, chemico-bonding to dentin, and stimulation of periapical healing. These advances represent not only progress in materials science but also improved biological understanding and long-term clinical performance.⁶

Bioceramic sealers are a relatively new advancement in the field of endodontic materials. These sealers, primarily composed of calcium silicate, exhibit bioactivity, are hydrophilic, and can chemically bond with dentin by forming hydroxyapatite (HA).^5,7 Their elevated pH and continuous release of calcium ions provide antimicrobial properties to aid in periapical tissue healing and reduce reinfection risk.⁸ Furthermore, their dimensional stability, superior flow characteristics, and ability to set in moist conditions make them particularly suitable for clinical scenarios where achieving optimal canal dryness is challenging.^2,5

An important but typically overlooked consideration in assessing root canal sealers is the monoblock. Monoblock, first reported by Tay and Pashley,⁹ is a bonded interface between a sealer, core material, and root dentin that provides a cohesive reinforced root structure and eliminates interfacial gaps. These authors proposed three categories: primary monoblock, defined as a single interface between the material and dentin; secondary monoblock, containing two bonded interfaces (i.e., core material to sealer and sealer to dentin); and tertiary monoblock, which features an intermediate layer (i.e., a bonding agent) between the bonded interfaces.¹⁰

With bioceramic sealers specifically, interest in secondary monoblocks has emerged because these materials chemically bond to dentin by forming HA during the setting reaction.¹¹ This bioactivity, combined with the hydrophilicity and dimensional stability of these bioceramic sealers, creates a filling complex that is theoretically fully integrated and better represents an idealized monoblock (i.e., bound to the dentin and core). Although full bonding at every interface is unlikely, the concept describes the clinical value of bioceramic-based obturation using the single-cone technique.¹² A discussion of this notion is important to understand the sealing ability, as well as the potential biomechanical reinforcement.

The advent of bioceramic sealers has led to a notable clinical shift toward the use of the single-cone obturation technique. Unlike traditional methods such as lateral condensation or warm vertical compaction, which depend heavily on the operator's skill to achieve a dense fill, the single cone technique leverages the sealer's properties to create an effective seal with minimal mechanical compaction.¹³ When employed with bioceramic sealers, the single-cone approach is believed to ensure long-term treatment success while simplifying the obturation process, reducing technique sensitivity, and potentially decreasing procedural errors.¹⁴

Despite ongoing skepticism, strong evidence supports single-cone obturation using bioceramic sealers.15, 16, 17 In vitro research has repeatedly demonstrated that bioceramic sealers better adapt to canal walls, more deeply penetrate dentinal tubules, and exhibit greater antibacterial properties than traditional resin-based sealers.^18,19 These findings indicate that bioceramic sealers have the potential not only to match but possibly exceed the clinical outcomes of conventional methods. Although laboratory findings do not always directly correlate with clinical success, the criteria for successful endodontic treatment— the absence of symptoms, radiographic signs of periapical healing, and long-term functional retention of the treated tooth—are well within reach owing to the advanced capabilities of bioceramic sealers.^20,21

Clinical literature presents a compelling case for the potential superiority of bioceramic sealers over traditional sealers. Several randomized controlled trials (RCTs) have demonstrated outcomes that are not only equivalent but often superior to those of bioceramic sealers.22, 23, 24 While some studies have reported no significant difference, many of these investigations were hampered by limitations including small sample sizes, short follow-up durations, and lack of blinding, which undermine the reliability of their conclusions.^8,20,22,25 The absence of a systematic, quantitative synthesis focusing exclusively on the clinical and radiographic outcomes from RCTs further underscores the need for a comprehensive evaluation. Addressing these gaps is imperative to fully appreciate the advantages offered by bioceramic sealers.

Considering these uncertainties, exploring the potential of single-cone obturation using bioceramic sealers is crucial to assess their utility as reliable and superior alternatives to conventional obturation techniques. The strength of bioceramic sealers lies in their ability to achieve equal or even greater treatment success through more efficient procedures.²⁶ This advancement may revolutionize clinical practice, especially in general dental settings where reducing technique sensitivity and shortening procedure time are highly prioritized. Furthermore, the biologically favorable characteristics of bioceramic sealers make them an excellent choice for patients with systemic health issues or in situations requiring rapid periapical healing.^24,27

This systematic review and meta-analysis aimed to address a significant gap in the existing literature by exclusively assessing RCTs comparing clinical and radiographic successes of single-cone obturation using bioceramic sealers with conventional obturation methods employing traditional sealers. By adhering to stringent inclusion criteria; namely, focusing on RCTs, permanent teeth, clearly defined clinical and radiographic outcome measures, and a minimum follow-up period of 6 months, this review seeks to offer a high level of evidence to guide clinical decision-making. In doing so, we not only assessed the effectiveness of bioceramic sealers in achieving clinical success but also examined their broader implications for modern endodontic practice. By providing clinicians, educators, and researchers with solid evidence, this study aimed to support the integration of biologically favorable, efficient, and predictable obturation protocols into routine care. Additionally, by identifying gaps in the current evidence, this study lays the groundwork for future well-designed studies to further refine endodontic standards and practices.

Assessing whether the anticipated benefits of bioceramic sealers and single-cone obturation techniques are realized in real-world clinical settings is crucial. The conclusions drawn from this systematic review and meta-analysis may shape treatment methodologies, influence material choices, affect patient outcomes, and drive the advancement of endodontic practice in this rapidly evolving discipline.

2. Materials & methods

2.1. Protocol registration

This systematic review and meta-analysis closely adhered to the 2020 Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD420250212604). The primary research question was formulated using the Population, Intervention, Comparison, and Outcome (PICO) framework, as shown in Table 1.

Table 1.

PICO framework for the systematic review question.

Population (P)	Patients receiving root canal treatment on permanent teeth.
Intervention (I)	Single-cone obturation employing bioceramic sealers.
Comparison (C)	Conventional obturation techniques utilizing traditional sealers, such as resin-based sealers.
Outcome (O)	Treatment success as assessed through clinical and radiographic evaluations.

2.2. Search strategy

We extensively searched three primary electronic databases (PubMed, ScienceDirect, and the Cochrane Library) from their inception to March 31, 2024. Our search strategy employed a mix of Medical Subject Headings (MeSH) and free-text terms combined using Boolean operators. The keywords were: “bioceramic sealer,” “single cone,” “obturation technique,” “resin-based sealer,” and “root canal treatment.” The search was limited to RCTs and articles published in English. In addition to the database searches, we manually checked the reference lists of all included articles and relevant reviews to identify additional eligible studies.

2.3. Eligibility criteria

2.3.1. Inclusion criteria

• •To ensure the provision of high-quality, unbiased evidence, only RCTs were included.
• •Studies comparing single cone bioceramic obturation with conventional obturation techniques.
• •Interventions conducted exclusively on permanent teeth.
• •Studies evaluating both clinical and radiographic treatment outcomes with a minimum follow-up period of 6 months.
• •A minimum sample size of 10 participants per group and clearly defined and measurable primary outcome data.

2.3.2. Exclusion criteria

• •Non-randomized, retrospective, or observational studies such as cohort studies, case-control studies, and case series.
• •In vitro or animal studies.
• •Studies involving primary teeth or apical surgery.
• •Trials focused exclusively on postoperative pain without assessing treatment outcomes.
• •Articles with incomplete outcome data or follow-up durations of <6 months. Review articles, including narrative, systematic, scoping, and conference abstracts.

The deliberate inclusion of only RCTs was intended to enhance the internal validity of the meta-analysis and minimize the risk of selection and performance biases.

2.3.3. Study selection and screening

All identified records were imported into Zotero reference management software, where duplicates were removed using automated and manual processes. Two independent reviewers, F.E. and Y.E., screened the titles and abstracts for relevance. The full texts of potentially eligible studies were then obtained and independently evaluated against the inclusion criteria. Any disagreements encountered at any stage were resolved through discussion or involvement of a third reviewer, A. M. P.

2.3.4. Data extraction and management

We developed a standardized pre-pilot data extraction using Microsoft Excel. The following data were extracted independently by two reviewers:

• •Author(s), publication year, and country
• •Study design and sample size
• •Type and location of teeth treated
• •Participant demographics (age, sex)
• •Type of instrumentation system
• •Type of sealer and obturation technique used
• •Operator experience and number of visits
• •Irrigation protocol and magnification
• •Clinical and radiographic outcomes
• •Follow-up duration
• •Statistical methods used
• •Risk of bias assessment.

All extracted data were cross-verified by the reviewers for consistency.

2.3.5. Risk-of-bias assessment

Two reviewers independently evaluated the risk of bias for each study included in the analysis using the Cochrane Risk of Bias 2.0 (RoB 2). This tool assesses five critical areas: randomization process, deviations from intended interventions, missing outcome data, outcome measurements, and selection of reported results. We classified the studies as having low risk, some concerns, or high risk of bias. Any disagreements were resolved by consensus.

2.3.6. Transparency and fidelity to protocol

This systematic review followed a pre-registered protocol in the PROSPERO registry to increase methodological transparency and mitigate potential bias arising from protocol deviations. The protocol for the review, which includes predefined eligibility criteria, search strategy, and outcomes of interest, is open-access. To promote transparency, we also completed an eligibility table describing the inclusion and exclusion criteria used in each screening stage, in line with the PRISMA 2020 process (Supplementary Table S1). All reference management and screening processes were performed using Zotero, which allowed us to track and duplicate citations. The risk of bias for the included RCTs was independently evaluated by two reviewers and assessed using the Cochrane RoB 2.0 tool. We also used the Joanna Briggs Institute (JBI) checklist for RCTs to ensure the consistency and completeness of our assessment of studies in which reporting was unclear or incomplete. While we applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework to evaluate the certainty of evidence across outcomes, we acknowledge the inclusion of Bardini et al. and rated it as “high risk” owing to deviations from the intended protocols and unclear concealment of allocation, which reduced confidence in the pooled estimates. This weakness was accommodated by the overall GRADE rating and is reported in the Results and Discussion sections for interpretative purposes.

2.3.7. Data synthesis and statistical analysis

The meta-analysis applied a random-effects model to consider potential clinical and methodological heterogeneity between the reported RCTs. This model was required because of the anticipated differences in study design, patient populations, instrumentation systems, obturation technique, and operator experience. Unlike a fixed-effects model that only. We determined the odds ratios (ORs) with 95 % confidence intervals (CIs) at 6, 12, and 18 months after the procedure. We used Cochran's Q test and the I² statistic to assess heterogeneity, with an I² >50 % signifying considerable heterogeneity. Forest plots were generated for visual representation. We evaluated publication bias using funnel plots and Egger's regression test, with p < 0.05 considered statistically significant. All analyses were performed using suitable statistical software.

2.3.8. Quality of evidence assessment

We used the GRADE approach to assess the overall quality of evidence across various studies for each outcome, considering elements such as study limitations, inconsistency, indirectness, imprecision, and publication bias.

3. Results

3.1. Information sources, search strategy, and study selection

Our search of the three main electronic databases using the keywords described above identified 2,874, 2,042, and 1439 articles indexed in the PubMed, ScienceDirect, and Cochrane Library up to March 31, 2024. The manual search of the reference lists of relevant reviews and the included articles yielded two more articles. The full summary of the searched databases, search terms, inclusion filters, and the number of articles retrieved at each step are detailed in Table 2.

Table 2.

Information sources and search strategy.

Database	Keywords	Filters Applied	Articles Retrieved	Duplicates Removed	Articles Screened	Full-text Reviewed	Included Studies
PubMed	“bioceramic sealer” AND “single cone” AND “obturation technique” AND “root canal treatment”	English, RCT, up to March 2024	2874
ScienceDirect	“bioceramic sealer” AND “resin-based sealer” AND “root canal treatment”	English, RCT, up to March 2024	2042
Cochrane Library	“single cone” AND “obturation technique” AND “bioceramic”	English, RCT, up to March 2024	1439
Manual Search	Reference lists of relevant reviews and included articles	–	Additional 2
Total	–	–	6355	1543	4812	18	3

After accounting for 1543 duplicates, 4812 records remained for title and abstract screening. Title and abstract screening was conducted independently by two reviewers (F.E. and Y.E.) using predetermined eligibility criteria. The full texts of 18 articles were obtained for further assessment. Three of the 15 articles were excluded for non-randomized study design, in vitro or animal studies, not reporting clinical or radiographic outcomes, insufficient follow-up (<6 months), or the use of non-bioceramic sealers. Ultimately, three RCTs met all inclusion criteria and were included in the qualitative and quantitative syntheses. The entire study selection process is displayed in the updated PRISMA 2020 flow diagram (Fig. 1).

Fig. 1.

PRISMA 2020 flow diagram depicting study identification, screening, eligibility assessment, and inclusion

Abbreviations: PRISMA, Preferred Reporting Items for Systematic reviews and Meta-Analyses.

3.2. Study characteristics

The analysis included three RCTs28, 29, 30 involving 259 participants (range: 69–100 patients per study). The trials evaluated the performance of single-cone obturation with bioceramic sealers compared with traditional methods, such as warm vertical compaction or single-cone techniques using resin-based sealers. The investigations covered treatments for anterior, premolar, and molar teeth, addressing both initial treatments and retreatment scenarios. Evaluations were conducted at 6, 12, and 18 months to monitor progress. Treatment success was gauged by examining clinical indicators such as the absence of pain, swelling, and sinus tract, along with radiographic analysis of periapical healing, assessed using the Periapical Index or an equivalent measure. Table 3 provides a detailed overview of the sample characteristics, instrumentation systems, sealers, and clinical protocols used in each study.

Table 3.

Characteristics of the included randomized controlled trials.

Study	Study Type	Sample Size	Teeth Examined	Sex	BC Group	Control Group	Age (years)	System Used	Treatment Type	Outcome Measures	Follow-up Duration
Coşar et al., 202330	RCT	100	Mandibular molars	Males/Females	MTA Fillapex, Dentsply BC sealer/Single cone	Resin-based sealer/Single cone	<35 (8),≥35 (36)	WaveOne Gold	Primary	Clinical signs (pain, swelling, sinus tract); Radiographic healing (PAI)	6, 12, 18 months
Kim et al., 202229	RCT	90	Anterior, premolar, molar	39/35	Endoseal BC sealer/Single cone with accessory cones	Resin-based sealer/Continuous wave condensation	>50 (25),≤50 (49)	Operator preferred	Primary and Retreatment	Clinical and radiographic success (symptom resolution and periapical healing)	6, 12, 18 months
Bardini et al., 202128	RCT	69	Anterior, premolar, molar	30/39	BioRoot RCS/Single cone	ZOE sealer/Warm vertical compaction	55.44 ± 15.04/56.37 ± 20.21	ProTaper Next + Gates Glidden	Primary and Retreatment	Clinical signs; PAI scores	6, 12 months

Abbreviations: RCT, randomized controlled trial; BC, bioceramic; MTA, mineral trioxide aggregate; PAI, periapical index; ZOE, zinc oxide eugenol; RCS, root canal sealer.

3.3. Risk of bias assessment

The risk of bias was assessed using Cochrane RoB 2.0 in the three RCTs. The study by Coşar et al.³⁰ showed a low risk of bias across all domains. The study by Kim et al.²⁹ presented some concerns primarily related to the randomization process. The study by Bardini et al.²⁸ was classified as having a high risk of bias due to deviations from the protocol and unclear allocation concealment (Fig. 2).

Fig. 2.

Risk of bias assessment of the included studies.

3.4. Quantitative analysis (meta-analysis)

3.4.1. 6-Month follow-up

After six months, the bioceramic sealer group showed a combined success rate of 88.7 % ± 4.6 %, compared with 76.4 % ± 15.6 % in the control group, although the difference was not statistically significant (OR = 2.09; 95 % CI: 0.76–5.87; p = 0.154). The bioceramic sealer and control groups exhibited moderate (I² = 63.3 %) and very high (I² = 96.1 %) heterogeneity, respectively (Fig. 3).

Fig. 3.

Forest plot comparing success rates between the bioceramic sealer and control groups at 6 months

Abbreviations: WMP, weighted mean proportion; SE, standard error; CI, confidence interval; QH, qualitative heterogeneity; OR, odds ratio.

3.4.2. 12-Month follow-up

After 12 months, the bioceramic sealer group achieved a success rate of 87.1 % ± 3.7 %, compared with 76.4 % ± 15.6 % in the control group, although the difference was not statistically significant (OR = 1.62; 95 % CI: 0.50–5.31; p = 0.424). The level of heterogeneity was moderate (I² = 57.5 %) (Fig. 4).

Fig. 4.

Forest plot comparing success rates between the bioceramic sealer and control groups at 12 months

Abbreviations: OR, odds ratio; SE, standard error; CI, confidence interval; QH, qualitative heterogeneity.

3.4.3. 18-Month follow-up

At 18 months, the success rates were 92.0 % ± 3.0 % in the bioceramic sealer group and 90.7 % ± 3.2 % in the control group, demonstrating nearly equivalent performance. The odds ratio was 1.12 (95 % CI: 0.38–3.25; p = 0.845), with no heterogeneity detected (I² = 0 %) (Fig. 5).

Fig. 5.

Forest plot comparing success rates between the bioceramic sealer and control groups at 18 months

Abbreviations: OR, odds ratio; SE, standard error; CI, confidence interval; QH, qualitative heterogeneity.

3.4.4. Publication bias

The funnel plot to evaluate publication bias across the three studies showed symmetry, with Egger's regression test results confirming the lack of publication bias (intercept = −0.619; p = 0.84) (Fig. 6).

Fig. 6.

Funnel plot of the effect size versus standard error with 95 % confidence limits. The symmetry suggests no publication bias (Egger's test: p = 0.84)

Abbreviations: OR, odds ratio; CI, confidence interval.

3.4.5. Overall GRADE quality of evidence

Although we included only RCTs, the overall certainty of the evidence was reduced due to concerns regarding bias risk, inconsistency, and lack of precision. While the findings suggested a tendency toward better outcomes with bioceramic sealers, additional high-quality, large-scale RCTs are needed to enhance the reliability of this conclusion (Fig. 7).

Fig. 7.

GRADE assessment of the included clinical trials

Abbreviations: GRADE, Grading of Recommendations Assessment, Development and Evaluation; RCT, randomized controlled trial.

4. Discussion

The results of this systematic review and meta-analysis underscore the potential of single-cone obturation with bioceramic sealers to improve endodontic success rates compared with traditional methods using conventional sealers. In three rigorous RCTs28, 29, 30 involving 259 participants, bioceramic sealers consistently demonstrated higher success rates at 6, 12, and 18 months. Although these differences lacked statistical significance, the aggregated ORs at all time intervals (6, 12, and 18 months) consistently favored bioceramic sealers (OR range 1.12–2.09), suggesting a possible advantage that warrants further exploration. Despite the broad confidence intervals and moderate heterogeneity at earlier follow-up stages, the bioceramic group showed a tendency to achieve better outcomes. Importantly, we observed no publication bias, and although the overall quality of evidence was rated as low by the GRADE framework owing to the risk of bias, inconsistency, and imprecision, the results strongly indicated that bioceramic sealers are a promising direction for future research and clinical practice.

The heterogeneity observed at the 6- and 12-month follow-ups merits further consideration. Moderate heterogeneity (I² = 63.3 % and 57.5 %) at these time points may be attributed to differences in the types of bioceramic sealers used, types of teeth treated, and operator techniques used across the studies. The combination of primary and retreatment cases, along with treatment methods, may also have influenced this heterogeneity. Despite these differences, the overall direction of the effect favored bioceramic sealers, which may be the result of the biological advantages of the material, regardless of the clinical conditions. At the 18-month time point, we observed no heterogeneity (I² = 0 %), suggesting that the treatment outcomes converged, which may reflect the stabilization of the healing response over time. The limited number of studies precluded subgroup analysis, which is one of the limitations of this study, and prevented a full exploration of the heterogeneity. Future reviews with larger datasets are needed to assess this observation through meta-regression or stratified synthesis.

Our findings strongly support the expanding body of evidence highlighting the considerable benefits of bioceramic sealers in root canal treatment.³¹ Although earlier systematic reviews and meta-analyses suggested these advantages, they often lacked robustness due to their dependence on observational studies, in vitro research, or varied outcome measures. Significantly, a systematic review emphasized the exceptional dentinal tubule penetration, dimensional stability, and push-out bond strength of bioceramic sealers, which surpass epoxy resin-based alternatives.³¹ While the review mainly concentrated on laboratory results, it demonstrated substantial implications for clinical practice. Additionally, various meta-analysis^22,32,33 offer persuasive evidence that bioceramic sealers reduce postoperative pain compared with resin-based sealers. Although the long-term success of this treatment has not been evaluated, its immediate advantages are clear and merit serious consideration for clinical use. The main differences between bioceramic and traditional resin-based sealers across several endodontic success-related criteria are compiled in Table 4 to further highlight these clinical consequences.

Table 4.

Comparative summary of bioceramic vs. resin-based root canal sealers.

Characteristic	Bioceramic Sealers	Resin-Based Sealers
Sealing Mechanism	Chemical bonding; hydroxyapatite formation	Mechanical retention; no chemical interaction
Biocompatibility	Excellent; promotes tissue healing	Moderate; potential cytotoxicity during setting
Antimicrobial Properties	Strong (due to high pH and Ca2+ ion release)	Limited and variable
Moisture Tolerance	Sets in moist conditions	Requires a relatively dry canal
Setting Expansion	Slight expansion (sealing benefit)	Shrinkage on setting (risk of microleakage)
Technique Sensitivity	Low; ideal for single-cone obturation	Moderate to high; often paired with warm vertical techniques
Radiopacity	Adequate to high	High
Postoperative Pain Profile	Associated with less postoperative discomfort (per recent studies)	Variable; higher rates of transient pain reported
Long-Term Evidence	Growing body of clinical data (5–10 years)	Well-established (10+ years)
Disintegration/Solubility	Low solubility; stable over time	Low to moderate solubility
Ease of Retreatment	Harder to remove due to bonding and apical adherence	Easier to soften and remove mechanically

Sealers with high solubility or poor adhesive properties create microgaps, which are potential sites for bacterial reinfection, ultimately leading to chronic periapical inflammation and possible treatment failure.^21,34,35 Accordingly, the material properties of root canal sealers; namely, sealing ability, dimensional stability, and resistance to dissolution/destruction, affect the long-term success of endodontic treatment. One prominent limitation of the included RCTs was their short follow-up time (6–18 months), which may not represent a full solubility profile or accurate long-term clinical durability of the materials. Bioceramic sealers show excellent dimensional stability and considerably lower solubility than resin-based sealers; hence, they may better retain apical seals over time. In contrast, resin-based sealers suffer from polymerization shrinkage, followed by degradation, which may compromise the seal, leading to tooth reinfection and failure.

The long-term success of root canal therapy is inherently related to the sealing ability and stability of the sealer used. The sealer interface can be breached, allowing bacteria to invade the canal system or fluid to percolate because of canal disinfection and system stability, leading to chronic periapical inflammation, reinfection, and treatment failure. Root canal sealers lacking dimensional stability or high solubility under physiological conditions fail due to degradation, eliminating the apical seal³⁶; Bioceramic sealers, on the other hand, have low solubility, chemical bonding via HA formation, and setting expansion, which contribute to a stable apical seal.^7,36 These characteristics imply that bioceramic sealers may greatly reduce microleakage-induced failures compared with traditional resin-based sealers that shrink upon polymerization and degrade over time. Again, the selection of sealer is not only a material choice but can also be the difference between positive or negative endodontic long-term prognoses.

Although bioceramic sealers have demonstrated favorable solubility properties in vitro, the RCTs in this review had relatively limited follow-up periods (6–18 months), which may be insufficient to detect potential long-term material degradation or compromised sealing performance. ISO standard 6876:2012 requires solubility of <3 % (mass) at the end of the test; while most bioceramic sealers remain well below this threshold in laboratory settings, other clinical aging and functional stresses may alter these properties.³⁷ Therefore, while these early clinical success rates are promising, the short durations of these studies limit the generalizability of these findings over the longer term.

This review marks a significant shift from earlier analyses by exclusively compiling high-quality evidence from RCTs and focusing only on the clinical and radiographic outcomes of healing. While the trend supporting bioceramic sealers observed in this study aligns with those of previous studies, the lack of significant differences requires before recommending a definitive change in clinical practice based solely on the current evidence. The clinical studies included in the present study used various obturation techniques: some used warm vertical compaction with traditional sealers, whereas others adopted modified single-cone methods. This variation is a key factor that could independently affect success rates, regardless of the sealer type. For instance, warm vertical compaction, despite being historically considered the gold standard, relies heavily on the operator's expertise and may introduce variables such as overfilling or insufficient apical sealing, which could greatly affect clinical outcomes.³⁸ Therefore, a cautious and deliberate approach is necessary before making any major changes in clinical practice.

The study by Bardini et al.,²⁸ demonstrated a more pronounced advantage for bioceramic sealers compared with the findings of the other two trials.^29,30 This could be attributed to the use of BioRoot RCS, a sealer with excellent biocompatibility and bonding strength, in conjunction with the single-cone technique, which might have influenced this outcome.³⁴ Nonetheless, due to methodological issues, including a high risk of bias,²⁸ these results should be interpreted with caution.

The results of this meta-analysis underscore that single-cone obturation with bioceramic sealers achieves clinical and radiographic success rates comparable to traditional techniques, while offering distinct advantages. These advantages include reduced technique sensitivity, the ability to set in moist environments, and inherent bioactivity, which enhance the appeal of bioceramic sealers for clinical application.^7,36 Adopting this innovative method could improve the reliability and efficiency of endodontic procedures, aligning with modern advancements in dental practice.

This review highlights important updates on the current status of bioceramic sealers in clinical practice. Zamparini et al.³⁹ conducted a systematic meta-analysis demonstrating improved radiographic healing and reduced extrusion rates for premixed bioceramic endodontic sealers, supporting their increased use in modern endodontic techniques. Similarly, Jaha³⁸ systematically reviewed hydraulic vs. thermoplasticized obturation methods, reporting that even the simplest approach (the single-cone method) also showed clinical success when paired with bioactive sealers.

Another important advancement is the thermal tolerance of bioceramic materials, a factor of particular relevance when used in conjunction with warm obturation techniques. Ashkar et al.³¹ investigated the physicochemical stability of calcium silicate-based sealers under thermomechanical stress, reporting that while most bioceramic sealers maintain their properties under moderate heat, extreme temperature release may affect their flow and bond strengths. Such findings may be useful for clinicians adapting bioceramics to existing warm compaction methods.

Endodontic obturation continues to evolve. The advent of bioactive nanomaterials (e.g., calcium phosphate nanoparticles and graphene-based fillers) may strengthen the antimicrobial and regenerative capabilities of current root canal sealers.⁴⁰ Additionally, machine-assisted obturation systems have been maturing to reduce operator variability, and artificial intelligence-augmented endodontic diagnostic and treatment planning, while still in the early phases of development, may yield useful adjuncts to treatment delivery.⁴¹ Furthermore, the use of bioceramic sealers has renewed interest in hydraulic condensation versus thermoplasticized techniques, with some suggesting that the one-cone method may see increased adoption due to its efficacy and reduced technique sensitivity.³⁸

However, the strategies for clinical procedures are shifting. Guidelines such as the updated European Society of Endodontology (ESE)-S3-level guidelines have highlighted the importance of emphasizing patient-reported outcomes (PROs) (e.g., postoperative pain, satisfaction, and quality of life) as important variables used to support technical success.⁴² These changes underscore the need for obturation approaches that are not only biologically compatible and efficient but also accommodate new models of patient-centered care. Future studies should focus on balancing material and clinical advancements with patient experience.

The single-cone technique combined with a bioceramic sealer is a highly viable alternative for dental practitioners, particularly those working in general practice or without access to advanced obturation tools.⁴³ The exceptional hydrophilic nature and chemical bonding ability of bioceramic sealers effectively compensate for any minor shortcomings in mechanical compaction, providing a dependable alternative to more technique-sensitive approaches.

For patients with reduced healing abilities, such as the elderly, those with diabetes, or individuals with weakened immune systems, the biological characteristics of bioceramic sealers, especially their ability to promote mineralized tissue formation, offer a significant therapeutic benefit.⁴⁴ Healthcare providers must understand the potential of bioceramic sealers to transform treatment outcomes for these at-risk populations. Although comprehensive long-term data supporting the superior effectiveness of bioceramic sealers are still being generated, their use should not be discouraged. Instead, the choice of sealer and obturation technique should be carefully customized for each situation, utilizing clinical knowledge and available resources to optimize patient outcomes.^45,46

This systematic review and meta-analysis has several strengths that bolster the reliability and validity of our conclusions. Initially, the review adhered to a pre-registered protocol in the PROSPERO database and complied with the PRISMA 2020 guidelines, ensuring methodological transparency and reducing the risk of selective reporting. We also employed strict inclusion criteria, concentrating solely on RCTs to enhance the internal validity and the level of evidence provided. Notably, we synthesized only clinical and radiographic healing outcomes, focusing on outcomes of direct clinical relevance rather than surrogate- or laboratory-based endpoints. We systematically evaluated the risk of bias of the included studies using Cochrane RoB 2.0, and assessed potential publication bias using both visual inspection of funnel plots and Egger's statistical test, offering a comprehensive evaluation of the trustworthiness of the findings. Additionally, the review extended the follow-up period to 18 months, providing valuable insights into the medium-term clinical performance of bioceramic sealers compared with conventional obturation techniques.

One of the primary limitations of this review was its focus on single-cone obturation techniques. Although the use of a single cone is increasingly popular because it is viewed as a simple obturation technique and works well with bioceramic sealers, it does not represent the full range of current obturation activity. Many widely accepted obturation techniques are currently used, including warm vertical compaction, carrier-based systems, and hydraulic condensation, which may have different performance characteristics, particularly when used with bioceramic or hybrid sealers. Their exclusion reduces the external validity and applicability of our results to real-world contexts. Future systematic reviews that consider additional obturation methods may be helpful for clinicians in varied practice settings.

Moreover, the present review only included three eligible RCTs; therefore, strong, reliable, meta-analytic inferences and advanced subgroup analyses were not possible. The lack of clinical trial data found here reflects a significant gap in clinical research and the need for robust, multicenter RCTs comparing multiple obturation methods and sealer types with long-term follow-up. Although it follows outcomes for 18 months, this follow-up duration is still a short-to-mid-term outcome and simply an increased length of follow-up, and further follow-up of at least 24 months is needed to evaluate the long-term stability of periapical healing due to the slow nature of bone regeneration.³⁹ Moreover, variables such as postoperative pain intensity, patient satisfaction, and quality of life, which are increasingly recognized as critical components of treatment success, have not been evaluated, thereby limiting the holistic understanding of the impact of obturation strategies from the patient's perspective.

Furthermore, the lack of PROs, including postoperative pain intensity, functional impairment, and satisfaction, limited the clinical applicability of our synthesis. Recent guidelines, like ESE-S3 guidelines for bioceramics, recommend including PROs as essential indicators of endodontic experience success.⁴² Evidence now suggests that bioceramic sealers are linked to lower postoperative pain than resin-based sealers.^23,25 Therefore, future research should consider the use of validated patient-reported instruments to provide a patient-centric measure of the impact of treatment on the patient's life or endodontic experience and to conform to the vision of current patient-centered care systems.

5. Conclusions

In summary, the meta-analytic estimates in the present study indicated the possible benefit of bioceramic sealers; however, the absence of statistical significance and the overall low certainty of evidence underscore the need for additional high-quality randomized controlled trials to establish clear clinical recommendations. These innovative materials perfectly align with the core principles of modern endodontic therapy, which prioritize biological compatibility, enduring sealing capabilities, and minimally invasive techniques. The insights from this review are not merely suggestive but rather a call for more definitive, large-scale studies. These findings equip clinicians with crucial knowledge to make informed decisions, thus ensuring the selection of the most effective obturation strategy for delivering predictable patient-centered care. The time to embrace bioceramic sealers is now, as they represent the future of endodontic excellence.

Patient consent

Not applicable.

Patient/guardian consent

This constituted a systematic review and meta-analysis of pre-existing studies; therefore, patient or guardian agreement was not necessary.

Ethical clearance

Not required.

Ethical statement

This systematic review and meta-analysis studied information already reported in prior studies. An ethical approval was not required for this study, since new datasets were not collected. The Institutional Ethics Committee therefore waived ethical approval.

Source(s) of support

The authors received no specific funding for this study.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Appendix A. Supplementary data

The following is the supplementary data to this article: