Pulp capping is a vital pulptherapy technique in dentistry designed to protect and promote the healing of the dental pulp when it is exposed or nearly exposed due to caries, trauma, or restorative procedures, with the goal of preserving tooth vitality and avoiding more invasive treatments such as root canaltherapy.[1] This procedure involves the application of biocompatible materials to stimulate reparative dentin formation and seal the pulp from bacterial invasion.[2]There are two primary types of pulp capping: direct pulp capping, which places a biomaterial directly over an exposed coronal pulp after caries excavation to induce healing and mineralized tissue barrier formation, and indirect pulp capping, which is used when the pulp is not yet exposed but is threatened by deep carious lesions, involving partial caries removal and placement of a protective layer over the thin remaining dentin to allow natural repair.[2][3] Direct pulp capping is indicated for small, clean exposures in pulps diagnosed with reversible or potentially irreversible pulpitis, while indirect pulp capping is preferred for deep cavities to minimize risk of exposure during treatment.[1]The procedure for pulp capping requires meticulous steps, including complete caries removal, assessment of pulp health using diagnostic tests like cold stimulation or percussion, achieving hemostasis within 5 minutes often using sodium hypochlorite irrigation, application of the capping material, and immediate restoration with a well-sealed coronal material to prevent microleakage and reinfection.[1] Common materials include calcium hydroxide, which has a high pH to stimulate fibroblasts but variable long-term success rates of 37-81.8% over 10 years; mineral trioxide aggregate (MTA), a calcium silicatecement offering superior sealing and success rates up to 97.96% over 9 years; and Biodentine, which sets faster with success rates around 96% over 3 years.[2]Success of pulp capping depends on factors such as the absence of irreversible pulpitis or infection, effective bleeding control within 5 minutes, use of magnification for precise diagnosis, and prompt restoration, with overall outcomes improved in immature teeth and when calcium silicate-based materials are employed.[1] Guidelines from the American Association of Endodontists emphasize accurate diagnosis, complete debridement, and biocompatible materials to achieve high success rates, positioning pulp capping as a conservative alternative that maintains natural tooth structure and function.[1]
Background and Principles
Definition and Purpose
Pulp capping is a dental technique designed to protect the vital dental pulp from bacterial invasion when it has been exposed or nearly exposed during restorative procedures, such as caries excavation or trauma, by applying a biocompatible material to seal the site and facilitate healing.[2] This approach promotes the formation of a mineralized tissue barrier, often referred to as reparative dentin or a dentin bridge, which isolates the pulp and supports its recovery.[1] As a subset of vital pulp therapy, pulp capping specifically targets the preservation of pulp function in teeth with minimal injury, distinguishing it from more extensive interventions like pulpotomy.[4]The primary purpose of pulp capping is to maintain the vitality of the dental pulp, thereby avoiding the need for more invasive treatments such as root canal therapy, and to preserve the overall structural integrity of the tooth.[1] By stimulating reparative dentinogenesis, it enables the pulp to respond to injury through natural healing processes, particularly in cases of reversible pulpitis where inflammation is mild and reversible.[2] This technique is especially valuable in young permanent teeth or those with immature apices, where preserving pulp vitality supports continued root development.[4]Successful pulp capping relies on key prerequisites, including a healthy pulp that exhibits a favorable response to injury, characterized by vitality and absence of irreversible inflammation, as confirmed through clinical assessment.[1] Equally critical is the adherence to strict aseptic techniques to minimize contamination, such as using rubber dam isolation and sterile irrigants, ensuring an environment conducive to pulp repair.[4] Pulp capping encompasses direct and indirect variants, with direct applied to exposed pulp and indirect to nearly exposed sites; further details on these are addressed in subsequent sections.[2]
Biological Mechanisms
When the dental pulp is exposed to injury, such as through caries or trauma, it initiates a complex inflammatory response aimed at defense and repair. The initial phase involves acute inflammation, characterized by the influx of polymorphonuclear leukocytes, vasodilation, and the formation of a blood clot at the exposure site, triggered by neuropeptide release and innate immune activation via toll-like receptors (TLRs) on odontoblasts.[5] If the injury is mild and bacteria are controlled, this progresses to reversible pulpitis, where inflammation resolves without progressing to irreversible damage or necrosis, allowing the pulp to maintain vitality.[6] In contrast, severe or persistent stimuli lead to chronic inflammation dominated by lymphocytes and macrophages, which can impair healing.[7]Central to pulp repair is the recruitment and differentiation of odontoblasts and stem cells to form reparative dentin, a mineralized barrier that seals the injury. Dental pulp stem/progenitor cells (DPSCs), primarily located in perivascular niches, migrate to the site of damage within hours to days, guided by chemokines such as CXCL8 and CCL2 produced by surviving odontoblasts.[5] These DPSCs differentiate into odontoblast-like cells in the initial phase post-injury, initiating reactionary or reparative dentinogenesis at a rate of about 4 μm per day, similar to primary dentin formation.[6] This process is modulated by growth factors, notably transforming growth factor-beta (TGF-β), released from the demineralized dentin matrix during injury; TGF-β enhances odontoblastic differentiation, extracellular matrix production, and angiogenesis while promoting an anti-inflammatory environment through cytokines like IL-10.[8]Mineralization of the reparative dentin bridge occurs through the deposition of hydroxyapatite crystals, facilitated by matrix vesicles secreted by the new odontoblast-like cells and influenced by local calcium ion availability.[9] Bacterial exclusion is achieved via multiple mechanisms, including the production of antimicrobial peptides (e.g., beta-defensins) and nitric oxide by odontoblasts, recruitment of immune cells to phagocytose invaders, and the physical sealing provided by the dentin bridge, which prevents further microbial ingress and subsequent necrosis.[10] The pulp's regenerative capacity varies by tooth type and patientage; primary teeth exhibit a faster inflammatory response and higher density of immunocompetent cells, while permanent teeth in younger patients demonstrate superior healing outcomes—higher success rates often exceeding 90%—due to greater vascularity, active stem cell proliferation, and reduced fibrosis compared to older individuals.[11]Recent research as of 2025 has advanced understanding of these mechanisms, highlighting the role of DPSCs-derived extracellular vesicles in paracrine signaling to promote repair and angiogenesis, as well as epigenetic factors such as DNA methylation, histone modifications, and non-coding RNAs (e.g., miRNAs) in regulating odontoblastic differentiation and inflammation resolution.[12][13]
Direct Pulp Capping
Indications
Direct pulp capping is indicated for small mechanical, traumatic, or carious exposures (typically less than 1 mm) of a vital pulp in teeth diagnosed with reversible pulpitis, where the pulp appears healthy upon direct visualization, showing minimal inflammation and no signs of necrosis.[1][4] This procedure is particularly suitable for immature permanent teeth to promote continued root development (apexogenesis) and in primary teeth where preserving vitality avoids harm to the succedaneous tooth.[4][2]It is applicable when pulp exposure occurs during caries excavation or restorative procedures, provided there is no radiographic evidence of periapical pathology, internal/external root resorption, or prior irreversible damage.[1] The approach aims to stimulate reparative dentin bridge formation and maintain tooth vitality as a conservative alternative to pulpectomy.[2]
Contraindications
Direct pulp capping is contraindicated in cases of irreversible pulpitis, characterized by spontaneous or prolonged pain, significant inflammation, or pulp necrosis, as these conditions reduce the likelihood of healing.[1] Uncontrolled hemorrhage after exposure, indicating potential infection or severe trauma, also precludes the procedure, necessitating pulpotomy or root canal therapy instead.[1][2]Radiographic signs of periapical radiolucency, root resorption, or abscess formation signal advanced pathology incompatible with vital pulp preservation.[4] In primary teeth, it is not recommended for carious exposures larger than 1 mm or in non-vital pulps, due to risks of internal resorption or interference with exfoliation.[4] Teeth with poor restorability or extensive structural damage are unsuitable, as adequate sealing cannot be ensured.[2]
Clinical Procedure
The direct pulp capping procedure begins with proper isolation using a rubber dam to prevent contamination, followed by complete removal of caries using magnification (e.g., loupes or microscope) to assess the exposure site and pulp health.[1][2]Hemostasis is achieved by irrigating the exposure with 5.25% sodium hypochlorite for 5-10 minutes, often using a soaked cotton pellet, ensuring bleeding stops within 5 minutes to confirm pulp vitality.[1] A biocompatible material, such as mineral trioxide aggregate (MTA) or calcium hydroxide, is then applied directly over the exposure to promote healing and dentin bridge formation.[4][2]The tooth is immediately restored with a well-sealed permanent coronal material (e.g., composite) to prevent microleakage and bacterial ingress.[1] Pre- and post-operative radiographs evaluate pulp proximity, exposure, and any pathology, with follow-up assessments at 6-12 months to monitor vitality, symptoms, and bridge formation.[4]
Indirect Pulp Capping
Indications
Indirect pulp capping is indicated for vital, asymptomatic teeth with deep carious lesions approaching the pulp on radiographs, such as those within approximately 1 mm of the pulp chamber, where the diagnosis is reversible pulpitis and complete caries removal would risk exposure.[4][14] This conservative approach preserves pulp vitality by leaving the deepest layer of carious dentin undisturbed, allowing for potential healing and avoiding more invasive treatments.[15]The procedure is suitable for both primary and permanent teeth, particularly in cases involving multi-surface caries where stepwise or partial excavation minimizes the chance of exposure while enabling definitive restoration.[4] It is especially beneficial in young patients with immature permanent teeth, as their pulps exhibit enhanced healing capacity due to increased vascularity and cell proliferation.[4]In individuals at high risk for caries, indirect pulp capping supports remineralization of the affected dentin layer, transforming it into harder, more resistant tissue over time and reducing the need for pulpectomy.[16] This is feasible when the pulp remains responsive and the carious process has not progressed to irreversible inflammation.[15]Prior to treatment, pulp vitality must be confirmed through clinical tests such as thermal or electric pulp testing, alongside radiographic evaluation showing no periapical pathology.[17] Additionally, the absence of clinical signs like swelling, fistula, spontaneous pain, or abnormal mobility is required to ensure the pulp's reversible status and the procedure's success.[17]
Contraindications
Indirect pulp capping is contraindicated in cases of symptomatic irreversible pulpitis, characterized by spontaneous or prolonged pain, as this indicates advanced pulpal inflammation unlikely to resolve without more invasive intervention.[18]Pulp exposure during caries excavation also precludes indirect capping, necessitating a shift to direct pulp capping or pulpectomy to address the exposed vital tissue directly.[19] Additionally, radiographic evidence of pulp involvement, such as periapical radiolucency or internal/external root resorption, signals potential necrosis or irreversible damage, rendering the procedure unsuitable.[20]Teeth with poor prognosis, including non-restorable structures requiring extensive reconstruction beyond a simple crown or exhibiting excessive mobility, are not candidates for indirect pulp capping, as adequate sealing and long-term pulp protection cannot be achieved.[18] Patient non-compliance with necessary follow-up evaluations further contraindicates the approach, particularly the two-step variant, due to the risk of undetected pulpal complications without monitoring.[19]Active signs of infection, such as soft tissue swelling or the presence of a sinus tract (fistula), indicate periapical pathology or abscess formation, requiring endodontic treatment rather than conservative pulp protection.[19] In immature permanent teeth where apexification is indicated—typically due to non-vital pulp and open apices—indirect pulp capping is inappropriate, as it presupposes pulpal vitality essential for continued root development.[1] The two-step indirect pulp capping process may not be suitable when single-visit completion is preferred, such as in cases of logistical constraints or uncooperative patients unable to return for re-evaluation.[4]
Clinical Procedure
The indirect pulp capping procedure involves conservative caries removal to avoid pulp exposure while promoting remineralization of the remaining affected dentin and formation of reparative dentin.[4] This approach is particularly indicated for deep carious lesions in vital teeth where complete excavation risks irreversible pulpitis.[1]Proper isolation is essential to minimize bacterial contamination during the procedure; the rubber dam is the gold standard for achieving this.[4] Caries excavation begins with the removal of peripheral infected dentin using low-speed burs or hand excavators, leaving the soft central affected dentin undisturbed to prevent pulp exposure.[17] Caries detector dyes may be employed as adjuncts to identify and ensure selective removal of infected tissue down to firm dentin.[1]Two primary techniques are used: stepwise excavation and single-visit selective removal. In stepwise excavation, after partial caries removal, a biocompatible liner is placed over the remaining dentin to seal it, followed by a temporary restoration; the tooth is then re-evaluated after 6 to 12 months, at which point any residual soft dentin is removed and a permanent restoration is placed.[4][17] The single-visit option involves selective caries removal to hard surrounding dentin in one appointment, application of a thin liner for sealing and protection, and immediate placement of a permanent restoration, provided no pulp exposure occurs.[4]Throughout the procedure, radiographic assessment is performed pre- and post-operatively to evaluate caries depth, pulp proximity, and any periapical changes.[4] Postoperatively, patients are advised to use fluoride supplements or applications at intervals based on caries risk assessment to support remineralization, with scheduled recalls every 6 months to monitor pulp vitality, dentin bridge formation via radiographs, and absence of symptoms such as pain or swelling.[4]
Materials
Calcium Hydroxide
Calcium hydroxide, chemically known as Ca(OH)₂, is a traditional pulp capping material typically prepared as a paste that exhibits strong antimicrobial properties due to its high pH of approximately 12.5, which facilitates the dissolution of bacterial cell walls and promotes the initial formation of a dentin bridge.[21][22] The material's alkaline nature arises from the release of hydroxyl ions, creating an environment hostile to microbial growth while stimulating reparative dentinogenesis, though it also induces a superficial zone of coagulation necrosis beneath the forming bridge to protect underlying pulp tissue.[23][24]Historically, calcium hydroxide has been employed in pulp capping since the 1930s, when it was introduced by Hermann as a remineralizing agent capable of supporting pulp healing in both direct and indirect applications.[21][25] Over the decades, it became a cornerstone of vital pulp therapy due to its biocompatibility and ability to neutralize acidic byproducts from carious lesions, marking it as one of the earliest materials validated for preserving pulp vitality.[26]Among its advantages, calcium hydroxide is highly bactericidal, effectively eliminating residual bacteria in the pulp exposure site, and remains inexpensive and readily available in various formulations, making it accessible for widespread clinical use.[21][22] However, its limitations include high solubility in oral fluids, which can lead to material dissolution over time, poor long-term sealing against microleakage, and reduced mechanical strength, often necessitating an overlay with resin-modified glassionomer for adequate protection.[21][25]In preparation, calcium hydroxide is commonly mixed as a powder-liquid system, where the powder—often containing calcium oxide or zinc oxide—is combined with aqueous vehicles such as saline or water to form a workable paste with a setting time typically ranging from 10 to 30 minutes, depending on the formulation and environmental humidity.[22] Paste-paste systems, involving a base and catalyst, offer improved handling properties through acid-base reactions that enhance initial stability, though the material's low elastic modulus and compressive strength limit its standalone durability.[21]While calcium hydroxide remains a foundational agent, modern alternatives like mineral trioxide aggregate provide superior sealing and biocompatibility, addressing some of its inherent solubility issues.[2]
Mineral Trioxide Aggregate
Mineral Trioxide Aggregate (MTA) is a bioactive endodontic cement introduced in the 1990s by Mahmoud Torabinejad as an advancement over traditional materials like calcium hydroxide for vital pulp therapies, including pulp capping.[27] It serves as a gold-standard capping agent due to its ability to induce reparative dentin formation while maintaining pulp vitality.[28]The composition of MTA is Portland cement-based, primarily consisting of tricalcium silicate, dicalcium silicate, tricalcium aluminate, and bismuth oxide as a radiopacifier, with minor components like gypsum for setting control.[29] Upon mixing with distilled water at a powder-to-liquid ratio of 3:1 to 4:1, MTA achieves a putty-like consistency suitable for placement.[30] In a moist environment, such as that of exposed pulp, it hydrates to form calcium silicate hydrate gel and calcium hydroxide; the latter reacts with phosphate ions in tissue fluids to precipitate hydroxyapatite, contributing to its bioactivity and integration with dentin.[30]MTA demonstrates high biocompatibility, forming a hermetic seal that prevents microbial leakage and promotes thick, continuous dentin bridges without adjacent pulpnecrosis.[28] Its elevated pH during initial setting (around 12.5) provides antibacterial effects by inhibiting bacterial growth, while the bismuth oxide ensures radiopacity for clear postoperative assessment.[29] These properties support its application in both direct and indirect pulp capping procedures, where it encourages odontoblastic differentiation and mineralized tissue deposition.[27]Key advantages of MTA include its bioinductive nature, which fosters pulp repair, and versatility across endodontic applications beyond capping.[29] However, disadvantages encompass its relatively high cost compared to other cements, prolonged setting time of 2-4 hours that may necessitate interim moisture retention with a damp cotton pellet, and potential for coronal tooth discoloration over time due to bismuth oxide oxidation.[27] Handling can be challenging owing to the granular powder, though resin-modified, light-curable variants have been developed to shorten setting and improve adaptability in clinical settings.[30]
Biodentine and Bioceramics
Biodentine is a tricalcium silicate-based bioactive material primarily composed of tricalcium silicate in its powder form, combined with a liquid containing calcium chloride and hydrosoluble polymer for setting.[31] Introduced in 2010 by Septodont, it serves as a dentin substitute in vital pulp therapy, offering a fast setting time of approximately 12 minutes, which allows for immediate restoration and reduces the risk of contamination during procedures.[32] Its bioactivity promotes the formation of mineralized tissue tags that integrate with the underlying dentin, mimicking natural mineralized structures and supporting pulp-dentin complex repair.[33]Bioceramics, such as EndoSequence BC Root Repair Material (RRM), represent a class of bioactive calcium silicate-based materials designed for endodontic applications including pulp capping.[34] These materials exhibit bioactivity by releasing calcium ions that facilitate remineralization of surrounding tissues through the formation of hydroxyapatite-like deposits.[35] EndoSequence, in particular, demonstrates high compressive strength, enhancing its durability in load-bearing areas while maintaining biocompatibility with pulp tissues.[36]As advancements over mineral trioxide aggregate (MTA), Biodentine and similar bioceramics provide faster setting times—typically under 15 minutes compared to MTA's hours—reducing chair time and improving clinical efficiency in both direct and indirect pulp capping procedures.[37] They also exhibit less tooth discoloration due to their composition lacking heavy metal oxides present in traditional MTA formulations, making them preferable for anterior restorations in vital pulp therapy.[38] These properties position bioceramics as versatile options for preserving pulp vitality by promoting sealing, antibacterial effects, and tissue regeneration without necessitating immediate full coverage.Despite these benefits, limitations include a higher cost compared to conventional materials, potentially impacting accessibility in routine practice, and a technique-sensitive mixing process that requires precise proportions to achieve optimal consistency and avoid setting failures.[39] Recent studies from 2023 and 2024 have demonstrated enhanced pulp healing with Biodentine, showing superior bridge formation and reduced inflammation in direct capping scenarios compared to older alternatives, with histological evidence of thick, continuous dentin bridges in human trials.[40][41]
Other Materials
Zinc oxide eugenol (ZOE) serves as a sedative agent primarily in indirect pulp capping procedures, where it provides temporary relief and seals against bacterial ingress, but its cytotoxicity to vital pulptissue renders it unsuitable for direct application.[42][43] Studies indicate that ZOE induces inflammatory responses and fails to promote dentin bridge formation when placed directly on exposed pulp, leading to recommendations against its use in such scenarios.[44]Glass ionomer cements and resin-modified variants offer adhesive properties and sustained fluoride release, making them viable for indirect pulp capping to remineralize dentin and inhibit caries progression near the pulp.[45][46] However, their initial acidity can cause pulpal irritation, limiting their efficacy and biocompatibility for direct pulp capping compared to less acidic alternatives.[47]Emerging materials include platelet-rich fibrin (PRF), which 2023 studies demonstrate as a biocompatible scaffold for direct pulp capping by releasing growth factors that support dentin bridge formation and pulp vitality preservation.[48]Tideglusib, a glycogen synthase kinase-3 (GSK-3) inhibitor explored in 2024 research, aims to enhance regenerative processes in pulp capping by stimulating odontoblastic differentiation, though animal models reveal potential for increased inflammation and soft tissue disorganization.[49][50] Similarly, nano-apatite combined with doxycycline, investigated in 2025 studies, targets anti-inflammatory effects to reduce pulpitis while promoting healing, positioning it as a novel strategy for capping inflamed exposures.[51]Dentin bonding agents facilitate adhesion between restorative materials and dentin but are not primary pulp cappers due to their cytotoxicity and inability to induce reparative dentinogenesis.[52] Bioceramics are generally preferred over these adjunct materials for their superior bioactivity and sealing in pulp capping applications.[53]
Clinical Outcomes
Success Rates for Direct Pulp Capping
Success in direct pulp capping is typically defined as the absence of clinical symptoms such as pain or swelling, maintenance of pulp vitality assessed through thermal and electric tests, and radiographic evidence of healing, including dentin bridge formation without periapical pathology.[54] These criteria are evaluated at follow-up intervals ranging from 6 months to several years, with success rates varying based on materials used and patient factors.[55]Overall success rates for direct pulp capping range from 80% to 97% at 1 year post-treatment, declining to 70% to 90% at 5 years due to progressive factors like bacterial ingress.[40] A 2024 systematic review and meta-analysis reported a weighted pooled success rate of 83% (95% CI: 79-87%) across studies on permanent teeth.[54] For mineral trioxide aggregate (MTA), success rates are higher, reaching 91% at 6 months and 84% at 2–3 years in a 2020 review of clinical outcomes, attributed to its superior sealing and biocompatibility.[56] Biodentine demonstrates a 99% success rate at 6 months in young permanent teeth as of 2025, with rates of 94% at 12 months and 87% at 18 months; long-term data beyond 18 months remain limited.[57]Success rates are notably higher for mechanical pulp exposures (92%) compared to carious exposures (33%), as mechanical exposures involve less inflammation and bacterial contamination.[58] In young patients with immature apices, rates exceed 90%, often reaching 95% at 1 year, due to enhanced reparative capacity of the pulp-dentin complex.[59] Failures are primarily linked to microleakage at the restoration interface. Indirect pulp capping generally exhibits higher baseline success rates than direct procedures involving exposed pulp.[2]
Indirect pulp capping demonstrates high success rates, typically ranging from 90% to 98% over 1 to 5 years of follow-up, reflecting its conservative approach to preserving vital pulp tissue without exposure.[60] This procedure promotes dentin bridge formation and caries arrest, with clinical and radiographic evaluations confirming pulp vitality maintenance in the majority of cases.[61]Studies on specific materials highlight these outcomes; for instance, tricalcium silicate-based agents like mineral trioxide aggregate achieve high success in vital pulp therapies. More recent evaluations report success rates for Biodentine between 80% and 100% in permanent teeth with deep caries.[62]Comparisons between stepwise and single-visit techniques show comparable efficacy, with success rates ranging from 60% to 88% for stepwise approaches up to 5 years.[63] In pediatric applications, the American Academy of Pediatric Dentistry (AAPD) guidelines from 2024 indicate success rates of approximately 83% for vital pulp therapies including indirect pulp capping in primary teeth at 24 months, with long-term rates affected by natural exfoliation.[64]Failure in indirect pulp capping often manifests as unintended pulp exposure during re-entry in stepwise procedures, occurring in 5% to 10% of cases, which may necessitate progression to more invasive treatments.[63] Overall, these rates are generally higher than those for direct pulp capping, benefiting from the absence of direct trauma to the pulp.[4]
Factors Influencing Outcomes
The success of pulp capping procedures is influenced by several patient-related factors. Younger patients, particularly those under 40 years of age, exhibit higher success rates due to enhanced pulp repair capacity, with studies reporting 90.9% success in this group compared to 73.8% in those 40 years and older when using Biodentine for direct pulp capping.[65] Systemic conditions such as diabetes mellitus can impair pulp healing and reduce treatment outcomes by increasing inflammation and delaying dentin bridge formation, as observed in both clinical and animal models.[66]Tooth-related variables also play a critical role. Mechanical pulp exposures generally yield better outcomes than carious exposures, with success rates of 92.2% for mechanical versus 33.3% for carious exposures in direct pulp capping procedures.[58] The quality of the final restoration is essential, as a hermetic seal prevents microleakage and bacterial ingress; inadequate restorations, such as amalgam compared to composite, increase failure risk by a hazard ratio of 2.263.[67]Operator-dependent factors significantly affect prognosis. Strict asepsis, including the use of rubber dam isolation, and effective hemostasis within 5–10 minutes are crucial for minimizing contamination and promoting healing.[68] Material selection further influences results, with bioceramics like mineral trioxide aggregate (MTA) and Biodentine outperforming calcium hydroxide, achieving success rates of 85.9–96.4% versus 77.6%, a difference of approximately 8–19%.[68]Regular follow-up with vitality testing and radiographic evaluation enables early detection of failures. Recent 2025 systematic reviews underscore the importance of isolation techniques in long-term success, emphasizing their role in both direct and indirect pulp capping.[68]
Complications and Management
Common Complications
One of the most frequent complications following pulp capping is pulp necrosis, occurring in approximately 10-20% of cases, particularly with direct pulp capping of carious exposures where bacterial contamination exacerbates inflammation. Signs include spontaneous or persistent pain, tooth discoloration, and radiographic evidence of apical radiolucency indicating pulpal death. This risk is notably higher in direct carious exposures compared to mechanical or traumatic ones due to pre-existing pulpal inflammation.[2]Microleakage at the restoration interface is another common issue, arising from inadequate sealing and leading to bacterial ingress, chronic inflammation, and potential secondary infection.[69] Adverse pulpal reactions, including chronic inflammation, may occur with eugenol-containing materials like zinc oxide-eugenol due to its cytotoxicity.[69]Material-specific complications include the solubility of calcium hydroxide, which can dissolve over time and result in dentin bridges with tunnel defects in up to 89% of cases, compromising long-term seal integrity.[2]Mineral trioxide aggregate (MTA) may cause tooth discoloration, particularly with gray formulations, affecting aesthetics in anterior teeth.Delayed complications often involve bridge failure, necessitating root canal treatment in 5-15% of cases at 5-year follow-up, with higher rates for calcium hydroxide (up to 44% failure) compared to MTA (around 19%).[70] In pediatric cases involving primary teeth, pulp capping failure can lead to premature loss and subsequent space maintenance issues.
Prevention and Treatment Strategies
Prevention of complications in pulp capping begins with meticulous procedural techniques to minimize contamination and promote healing. Strict use of a rubber dam is the gold standard for isolation during vital pulp therapy procedures, including direct and indirect pulp capping, as it prevents bacterial ingress from saliva and blood, thereby reducing the risk of pulp inflammation or necrosis. [64] Immediate sealing of the pulp exposure site with a biocompatible material after hemostasis is essential to create a protective barrier against further microbial invasion. [4]Patient education plays a crucial role, emphasizing rigorous oral hygiene practices such as twice-daily brushing, daily flossing, and avoidance of hard or sticky foods to support restoration integrity and prevent secondary caries. [71]Material selection should be tailored to the type of exposure; for direct pulp capping involving mechanical or carious exposure of vital pulp, mineral trioxide aggregate (MTA) is strongly recommended due to its superior sealing and biocompatibility compared to alternatives like calcium hydroxide. [64] Alternatives like Biodentine offer similar benefits with lower risk of discoloration.Ongoing monitoring is vital to detect early signs of complications, such as persistent sensitivity or radiographic changes indicative of pulppathology. Patients should undergo clinical recalls every 3 to 6 months post-procedure, incorporating electric pulp testing (EPT) to assess pulp vitality and periapical radiographs to evaluate dentin bridge formation and absence of periapical radiolucency. [72] Early intervention is advised if sensitivity persists beyond initial healing or if EPT responses deviate from baseline, allowing timely adjustment to prevent progression to irreversible pulpitis. [4]In cases of pulp capping failure, evidenced by clinical symptoms like prolonged pain or radiographic periapical lesions, treatment escalation is necessary to preserve tooth function. Options include transitioning to partial pulpotomy for localized inflammation or full pulpotomy/root canal therapy for more extensive involvement, with extraction considered only if restorability is compromised. [64] For immature permanent teeth following failed pulp capping, regenerative endodontic procedures are recommended per 2024 AAPD guidelines, involving disinfection of the canal and induction of vital tissue ingrowth to promote root maturation and apex closure, particularly in necrotic pulps with open apices. [4]Recent advances incorporate laser-assisted techniques for enhanced sterilization during pulp capping, which provide decontaminant effects and hemostasis, significantly reducing clinical and radiological failure rates with an odds ratio of 0.24 compared to conventional methods, thereby lowering infection risk and improving long-term success. [73]