Review of Calcium Hydroxide and Mineral Trioxide Aggregates for Direct Pulp Capping of Caries-Associated Pulp Exposures
Steven Hilmi, B.S., Alexander Komar, B.S., Jaryd Royer, M.A., C.D.T., B.A.
Background: Dental caries is a multifactorial infection of dental tissues. Untreated caries affect 35% of the global population, constituting the most prevalent disease evaluated across all medical conditions. Vital pulp therapy (VPT) techniques, specifically direct pulp capping (DPC), have seen significant clinical successes compared to more invasive treatments. Calcium Hydroxide (CH) is the predominant DPC material, though Mineral Trioxide Aggregates (MTAs) have demonstrated comparatively greater clinical efficacy. Recent material development and growing evidence address the primary barriers to MTA use, and provide critical data on the network of interactions involved in immune and regenerative responses to dental caries.
Objective: The objective of this review is to compare the efficacy of CH and MTAs in the treatment of caries-associated pulp exposure with DPC. To this end, the proposed review will answer the following questions:
- What are the comparative clinical success rates of CH and MTAs in DPC of iatrogenic pulp exposure?
- What are the comparative histological characteristics of CH and MTAs in DPC of exposed pulp?
- Is there a definitive advantage of DPC with MTAs versus CH in the treatment of iatrogenic pulp exposure? If so, what properties contribute to this advantage?
Methodology: Evaluation of DPC materials was conducted in a step-wise manner with regard to the given questions.
- Clinical evaluation was conducted through review of large randomized clinical trials with follow-up periods no less than two years. Two clinical studies met these criteria.
- Histological evaluation was conducted through review of studies performing DPC in vivo on human teeth with ex vivo histological analysis performed no less than three months post-extraction. (X) studies met these criteria
- Assessment of pertinent DPC material properties included review of material handling, cost-effectiveness, and potential pharmacodynamics from a variety of resources including manufacturer information and reviews, modified meta-analyses, and pre-clinical trials. (X) studies were included.
Findings: Following evaluation, direct pulp capping with CH exhibit a significant decrease in patient outcome success rate with follow-up times beyond two years, with MTA maintaining successful patient outcomes beyond two years. CH induced dentin-bridges show significantly variable thickness in both individual and inter-subject assessments; and they are on average thinner than those induced by MTA or Biodentine, exhibiting porosities and tunneling defects that are largely absent in MTA groups. Newer MTA formulations, such as Biodentine, have accounted for previous concerns of setting time, requisite technique, esthetics, and relative cost; the latter of which has been estimated as far more economically effective than CH over longer periods. While CH and MTA are similar in their mechanism of action, MTAs exhibit a significantly increased amount of Ca2+ release compared to CH. This difference in extracellular Ca2+ may account for the differential success rates of MTA in DPC.
Conclusion: Mineral Trioxide Aggregates (MTAs) have challenged CH, studies indicating greater success rates across all recognized clinical outcomes and cost-effectiveness, perhaps even challenging RCT for the first-line treatment of deep carious lesions.