Do the Benefits of MTA for Direct Pulp Capping Justify the Cost?
Direct pulp capping using mineral trioxide aggregate (MTA) is a predictable procedure when used for teeth diagnosed with normal pulps or those exhibiting reversible pulpitis. Compared with the cost of conventional root canal treatment paired with post and core placement and cuspal coverage restorations, direct pulp capping procedures using MTA, when indicated, are relatively inexpensive. The benefits of using MTA in vital pulp therapy procedures include maintenance of healthy gingiva and periodontium, preservation of the natural tooth structure, and continued apexogenesis in immature adult teeth. The cost of MTA can also be further reduced by placing the unused cement in an airtight container, providing enough material to further complete another three to five different procedures from one opened MTA packet.
Because teeth receiving root canal treatment and restorative care are more prone to failure due to fractures, microleakage, and the emergence or recurrence of periapical disease, the preservation of living pulp should not be viewed as an expensive treatment option, but rather as a reliable strategy to prevent or postpone more expensive dental procedures. In a greater sense, as dental care providers, it is our incumbent, ethical duty to deliver oral care that helps preserve natural tooth structure for improved oral health that most favorably benefits our patients.
The cost of MTA, compared with other pulp-capping agents used in vital pulp therapy, far outweighs the risks and consequences of more aggressive care. Further, pratice-based randomized clinical trials have shown that MTA provides superior performance as a pulp-capping agent when compared with lower-cost, calcium-hydroxide (CaOH)–based pulp-capping agents.1 The question should not be whether the benefits justify the cost, but rather, can the cost of not using MTA be defended in view of the current scientific evidence that clearly demonstrates alternative treatment options showing lower long-term survival rates?
CaOH has been considered the “gold standard” of direct pulp capping materials for several decades due to its biocompatibility with the pulp, excellent antibacterial properties, and long-term track record of clinical success. However, CaOH is highly soluble and subject to dissolution over time, has no inherent adhesive qualities, and provides a poor seal to tooth structure.
MTA has generated considerable interest recently as a direct pulp-capping agent. Unset MTA is primarily CaOH, and the primary reaction product with water is CaOH. As such, both CaOH and MTA are believed to affect pulp repair by minimizing bacterial penetration to the pulp and through their high pH. This causes the release of bioactive molecules such as bone morphogenic protein and transforming growth factor-beta one, which have demonstrated the ability to stimulate pulp repair.
A significant difference between the materials is the fact that MTA provides a seal to tooth structure not found with CaOH. A significant drawback to MTA is the prolonged setting time of approximately 3 hours, although faster setting formulations are being developed.
Early human studies comparing MTA to CaOH in clinical settings demonstrated similar outcomes for both. However, two studies of very short duration (2 to 3 months) demonstrated superior performance of MTA.
Recently, more extensive clinical studies have demonstrated superior performance of MTA compared with CaOH in direct pulp capping. Mente and colleagues2 performed a retrospective case control study involving carious pulp exposures in an academic setting with a follow-up period ranging from 12 to 80 months (median 27 months). Hilton and colleagues1 reported on a practice-based, randomized clinical trial that evaluated and compared the success of direct pulp capping in permanent teeth using MTA or CaOH for 2 years. Both studies showed that MTA had a superior performance as a direct pulp-capping agent compared with CaOH.
Given the growing body of evidence showing the superior performance of MTA compared with CaOH in completing pulp caps, the benefits of MTA do justify the additional cost for its use as a direct pulp-capping agent.
1. Hilton TJ, Ferracane JL, Mancl L, Northwest Practice-based Research Collaborative in Evidence-based Dentistry (NWP). Comparison of CaOH with MTA for direct pulp capping: a PBRN randomized clinical trial. J Dent Res. 2013;92(7 suppl):S16S-S22.
2. Mente J, Geletneky B, Ohle M, et al. Mineral trioxide aggregate or calcium hydroxide direct pulp capping: an analysis of the clinical treatment outcome. J Endod. 2010;36(5):806-813.
About the Authors
George Bogen, DDS, is the staff endodontist for the Children’s Dental Health Clinic at Long Beach Memorial Hospital in Long Beach, California. He is a lecturer for the postgraduate departments at the University of California at Los Angeles, Loma Linda University, and Veterans Affairs Medical Center in Long Beach. Dr. Bogen maintains a private practice in Los Angeles, California.
Thomas J. Hilton, DMD, MS, is alumni centennial professor in operative dentistry at the Oregon Health & Science University in Portland, Oregon. He is co-director of the OHSU Practice-Based Research in Oral Health Network, and lead editor of Fundamentals of Operative Dentistry: A Contemporary Approach (4th edition).