Information provided by BISCO

	After more than five years of research and development, TheraCal LC was made available to clinicians in November 2011. It has been estimated that in the past three years, over five million restorations have been placed using TheraCal LC as a direct or indirect pulp capping material.

	The popularity and rapid growth of this product has certainly surprised 

, launching it to be one of their top selling products. It is wildly popular for use as a direct pulp-cap, yet remains underutilized as an indirect pulp-cap. Perhaps this is because it requires a little more material in this procedure, or perhaps it is due to a lack of understanding of how 

 can assist in facilitating the formation of reparative dentin, improving the prognosis of this procedure.   

	There are three types of pulp exposures: carious, mechanical and traumatic. Both mechanical and traumatic pulp exposures can be easier to treat due to their higher success rate. However, the carious exposure remains difficult to treat based on the level of pulpal inflammation and infection. Due to the often unpredictable pulpal response to direct pulp-capping of carious exposures, many clinicians opt for providing endodontic therapy every time the pulp is exposed. However, if the exposure is small and the pulpal status has been properly diagnosed, many clinicians are also finding success with direct pulp-capping by using TheraCal LC.

	Rarely does a clinician diagnose the pulpal status of a tooth prior to providing routine restorative fillings. Either a clinical or radiographic exam reveals the need for a direct filling. It should be recognized that the level of infection is frequently deeper than what a radiograph can provide. In addition, it is usually not until after the pulp is exposed that a clinician diagnoses the tooth as being either symptomatic or asymptomatic reversible or irreversible pulpitis. Regardless, it is the best practice to avoid exposing the pulp entirely unless there are clear indicators for providing root canal therapy.

	Knowing when to stop removing carious dentin can be difficult, especially when the exact location of a pulp horn or chamber is not known. Most clinicians rely upon tactile sensation or the hardness of the dentin to determine when to stop excavating. When near the pulp, it is advised to stop excavating and leave a layer of affected dentin.

	This affected dentin may be demineralized and softer than sound dentin, but preserves the collagen structure, lacks contamination with bacteria, can extend up to one mm and is capable of remineralizing. In contrast, infected dentin is softened dentin (demineralized and destroyed collagen) that remains infected with bacteria, and should be removed.

	The procedure by which incomplete excavation is provided, leaving a thin layer of affected or sound dentin when near the pulp, is called an indirect pulp cap. This procedure is usually more successful than a direct pulp cap, and can provide the tooth the opportunity to repair itself and maintain vitality.

	However, it has fallen out of favor with the introduction of self-etching adhesives, the additional cost of the indirect pulp capping material, and the lack of insurance reimbursement. It should be noted that adhesives are acidic, do not disinfect the dentin and do not provide the necessary chemicals for tooth remineralization. Providing an indirect pulp cap and/or liner with TheraCal LC has many benefits, that when combined with a well-sealed restoration, can allow the tooth many more years of service prior to endodontic treatment.

TheraCal LC is a light-cured, flowable resin-modified calcium silicate filled liner that can be used for direct and indirect pulp caps. TheraCal LC possesses many of the same beneficial properties similar to other commercially available self-curing MTA products. TheraCal LC’s proprietary resin formula consists of tri- and di-calcium silicate particles in a hydrophilic monomer that provides significant calcium and hydroxide ion release (Chart 1). These ions serve many roles in the ability to remineralize tooth structure via apatite formation in an alkaline environment. Stable and durable as a liner, base or pulp-capping material, it is permeable to dentinal fluid but resists dissolution.

	TheraCal LC may act as a scaffold for reparative dentin formation. Dentinal fluids are absorbed within it, resulting in the release of calcium and hydroxide ions, and the tooth responds to form apatite and a bond, supporting the natural sealing ability of the product. This ability to assist in the formation of apatite plays a critical role in pulpal protection.

		Isolate the tooth to be treated with a rubber dam. Research still indicates that this is the best technique to use.

		Excavate all infected dentin and leave a thin layer of affected dentin when near the pulp. Use maximum caution to avoid exposing the pulp.

		Clean the cavity with 2% chlorhexidine (

). Use a moist cotton pellet for at least 20 seconds.

		If a pulpal exposure occurs, control hemorrhage with sterile saline, chlorhexidine or sodium hypochlorite.

		Apply TheraCal LC to the pulpal floor of the prepared cavity up to 1mm. This will assist in reducing post-operative sensitivity via insulation. Make sure to apply to TheraCal LC to 

 dentin as this will improve its initial bond and stability.

		Light-cure TheraCal LC for 20 seconds. TheraCal LC is very opaque and requires a full cure.

		Selective etch the enamel (Select HV Etch) or total-etch the entire preparation.

		Fill preparation with restorative material of choice (composite, amalgam, core-buildup, etc.).

		Seal tooth-restorative margins with BisCover LV.

		Distal-occlusal caries present on an asymptomatic mandibular first premolar.

		Incomplete excavation of caries leaving affected dentin without exposing the pulp.

		Direct placement of TheraCal LC as an indirect pulp cap on entire pulpal floor.

		Thin layer of TheraCal LC after light-cure of 20 seconds.

	Key features and benefits of TheraCal LC

 release stimulates hydroxyapatite formation, secondary dentin bridge formation

		The alkaline pH (hydroxide ions) promotes healing

 and contributes to pulpal repair and apatite formation.

 that insulates the pulp (which may lead to less tooth sensitivity).

		Moisture tolerant with very low solubility

		High radiopacity making it easily identifiable on radiographs.

		Light-curable with immediate set and very easy to use.

 to withstand the forces of mastication under composites, amalgams, cements and other base materials.

		Flowable, yet stays where it is placed.

	1. Gandolfi MG, Siboni F, Prati C. Chemical–physical properties of TheraCal, a novel light-curable MTA-like material for pulp capping. International Endodontic Journal. 2012 Jun;45(6):571-9.

	2. ADA definitions for direct and indirect pulp capping at 

http://www.ada.org/en/publications/cdt/glossary-of-dental-clinical-and-administrative-ter

	a. direct pulp cap as a “procedure in which the exposed vital pulp is treated with a therapeutic material, followed with a base and restoration, to promote healing and maintain pulp vitality.”

	b. indirect pulp cap as a “procedure in which the nearly exposed pulp is covered with a protective dressing to protect the pulp from additional injury and to promote healing and repair via formation of secondary dentin.

	3. Apatite-forming Ability of TheraCal Pulp-Capping Material, M.G. GANDOLFI, F. SIBONI, P. TADDEI, E. MODENA, and C. PRATI J Dent Res 90
	(Spec Iss A):abstract number 2520, 2011 (

	4. Okabe T, Sakamoto M, Takeuchi H, Matsushima K (2006) Effects of pH on mineralization ability of human dental pulp cells. Journal of Endodontics 32, 198–201.

	5. Sangwan P; Sangwan A; Duhan J; Rohilla A. Tertiary dentinogenesis with calcium hydroxide: a review of proposed mechanisms. Int Endod J. 2013; 46(1):3-19

	6. Mechanical Properties of New Dental Pulp-Capping Materials Over Time. M. NIELSEN, R. VANDERWEELE, J. CASEY, and K. VANDEWALLE, USAF, JBSA-Lackland, TX, , J Dent Res 93(Spec Iss A): 495, 2014 (

Articles

A look at how Bisco's TheraCal LC could be used in your practice.

How to use TheraCal LC for direct and indirect pulp capping

We talk with Paul L. Child Jr., DMD, CDT, executive vice president of Bisco Dental Products about how eCEMENT is filling a gap not currently being serviced by others in the marketplace.

 This is an interesting case in which the growth of one material, lithium disilicate, sparked the development of another. How important is it to Bisco to remain responsive to trends?

: BISCO’s ability to be responsive to industry needs is only one key component of its overall global strategy. Setting the trends themselves is also a key strategy, such as with TheraCal LC. However, lithium disilicate as a material is hugely successful, and therefore it makes sense for BISCO to market a product that will complement it. 

CEMENT is just that-a complement to lithium disilicate, one that eliminates the confusion of which cement to use and when.

 At what point did the lithium disilicate boom command the interest of the Bisco R&D team? Or, more precisely, how long has 

Products take much longer to develop than what most dentists think. In addition to the initial research and development, there is a plethora of regulatory and marketing activities that must take place prior to launching a new product. Lithium disilicate has been an interest to BISCO for many years, and we have been testing many of our products in conjunction with it to ensure compatibility.

 We all know what a premium Bisco puts on quality R&D and the science behind its products. How do you know when a product is ready? What clinical evidence do you need?

: BISCO puts our products through rigorous and thorough testing to guarantee they will work in all clinical situations. Occasionally, if a product does not meet our standards, starting over may be considered, or at the very least, postponing a planned launch. We are more concerned with providing quality products that perform as indicated than just putting a product out on the market.

Unfortunately, clinical trials can take years to be accepted in the literature as clinical research, and is timely, expensive, and more difficult to conduct now than in previous years. For example, although there is 10 years of clinical data behind lithium disilicate, there are still many who may question it, or have yet to even use it. However, observation and new clinical research shows a fantastic success rate with this product, thus the introduction of 

CEMENT filling a gap not currently being serviced by others in the marketplace?

: There are many cementation systems available to the clinician today, ranging from resin-modified glass ionomer cements to self-adhesive resin cements to pure resin cements. This provides multiple types of cements for the clinician to choose from, but also may add confusion to the selection process.

BISCO wanted to simplify this and provide one kit for all types of lithium disilicate restorations: from veneers to crowns to bridges. The 

CEMENT system includes all the necessary components to successfully cement lithium disilicate restorations, and includes the silane, the etchant, and light-cured and dual-cured cement.

 How does this offering build on other key developments within the Bisco line of products?

CEMENT builds on our already successful line of cements that we have offered for more than decades. BISCO prides itself on its unique and effective chemistry of dual-cured materials, which offer properties not found elsewhere.

Our customers expect the best and highest quality products, and have become accustomed to having us deliver that. 

CEMENT follows in this tradition as a new and superior product with research and science as its foundation.

Designed for lithium disilicate restorations, Bisco’s 

CEMENT kit features high-strength resin cements formulated to provide better esthetics at the margin.

CEMENT offers a light-cure and dual-resin cement to ensure lithium disilicate restorations provide long-term retention of single or multiple restorations, as well as shade stability. Additionally, the radiopaque cement offers easy placement of lithium disilicate veneers, onlays, crowns, three-unit bridges and inlays.

CEMENT kits include resin cement, SELECT HV ETCH, ALL-BOND UNIVERSAL, PORCELAIN ETCHANT, and PORCELAIN PRIMER.

Dental Innovator: BISCO eCement simplifies cement selection process

Today’s dentistry allows us to offer a multitude of dental restorations to our patients. Our challenge as dentists is finding a predictable cementation protocol that will work with a majority of these restorations and also one that’s simple and stress-free.

, when used in combination, will help ensure a predictable and successful outcome every time.

BisCem is a dual-cured self-adhesive resin cement that’s designed to cement crowns, bridges, inlays, onlays and posts. BisCem also has been designed to bond to a multitude of dental substrates such as metals, composites, porcelain and amalgam, thus eliminating the need to etch and bond the prepared dental surface.

Additionally, it has a low film thickness, which ensures the restoration is completely seated, is formulated with glass ionomer benefits (fluoride release) with resin cement strength and is a radiopaque material that’s easily identified on radiographs.

 to allow for cohesive adhesion to oxide-based materials (zirconia, alumina and metal). Z-Prime Plus is a single- bottle priming agent and when applied to a retentive preparation will double the bond strength of BisCem to zirconia, alumina and metal.

Z-Prime Plus also can be used when preparations are short/tapered, non-retentive to increase the adhesion retention rate between the restoration and resin cement.

BisCem’s technique for placement is streamlined and the product can be used for a wide variety of cementation indications to help meet the challenges we currently face in our practices each day. BisCem and Z-Prime Plus are optimized for use with one another to help save dentists time and money while increasing patient satisfaction.

A pre-operative view of the case is provided in 

Remove the temporary restoration and all temporary cement residue. Clean the preparation with pumice and water. Rinse thoroughly (

A zirconia crown is prepared and positioned on a model (

Clean the internal surface, rinse and air dry. Then apply Z-Prime Plus (

Apply BisCem to the internal aspects to the crown and seat the restoration (

Light cure for 3-5 seconds and remove excess cement. Then light cure for 20-30 seconds. The occlusal view of the restoration after clean-up is shown in 

The lingual view of the restoration after clean-up is shown in 