Pulp capping agents are usually tested using histological approaches. Yes, they are odontoblast cell lines, but i have little references regarding its use. Please refer to Dr. Mary McDougall papers for more information. 

Dr. Cornelis Pameijer, University of Connecticut,  has done a lot of work in this field as well. PubMed is an excellent source for an overview of published work. 

In the ISO standards you will also find recommendations in relation to tests and documentation needed prior to commercialisation.

Thank you so much.

I have attached the latest proposed revision of the ANSI/ADA  guidelines. The changes that were made will be voted on in March during the IADR meeting, This may be helpful to you when testing materials for pulp capping.

6.5 Pulp capping test 6.5.1 Objective The test is designed to assess the biocompatibility of pulp capping materials with the dental pulp. Include in the assessment methodology procedures necessary for the proposed clinical use of the material. NOTE 1 With a few modifications, this test can be used for pulpotomy testing. NOTE 2 The pulp and dentin usage test and the pulp capping test may be performed at the same time in the same animals using different teeth. 6.5.2 Animals and animal welfare Conduct animal welfare in accordance with 6.4.2. Use a minimum of two non-rodent mammals of one species, as described in 6.4.2. Scale Odontoblast death 0 None 1 􏰄 25 % cell death 2 25 % to 50 % cell death 3 􏰅 50 % to 75 % cell death 4 􏰅 75 % cell death 14

6.5.3 Test procedure 6.5.3.1 Preparation of animals Select sufficient animals to provide at least ten teeth containing test material and 5 control teeth for each time period. Anesthetize the animals and carry out the procedure described in 6.5.3.2. 6.5.3.2 Treatment of teeth 6.5.3.2.1 Remove all calculus and debris from the tooth surfaces. Place a rubber dam to isolate the teeth to be used. Clean the tooth surface and the operating field and dry. Disinfect by swabbing with 3 % (volume fraction) hydrogen peroxide followed by a disinfectant consisting of povidone-iodine or chlorhexidine. Prepare the required number of Class V buccal or labial cavities using sharp burs under an adequate air-water spray. The preparations should be bordered by enamel but extend into the mesial and distal surfaces of the tooth and into the inner one-third of the dentin. In the center of the cavity, carefully make a pulpal exposure of approximately 0,5 mm to 1,0 mm diameter under a spray of sterile saline solution [0,9 % (mass fraction)] without plunging the bur into the pulp tissue. The approximate diameter of the exposure should be measured in tenths of a millimetre. The diameter of the exposure can be estimated from the known diameter of the bur. Thoroughly irrigate the exposure site with sterile saline solution until haemostasis is achieved. Dry with sterile cotton pellets. NOTE If animals have marked gingival inflammation, it might be necessary to carry out a calculus and debris removal a few days before cavity preparation and even repeatedly until gingival inflammation is controlled. 6.5.3.2.2 For the preparation of test materials, follow the manufacturer’s instructions. If the manufacturer recommends other irrigating solutions or reagents for the termination of hemorrhage or specific pre-treatment of the pulp wound, follow the manufacturer’s instructions. 6.5.3.2.3 For each time period fill at least ten cavities with the test material and five with a suitable reference material on the basis of a random allocation. Mix the capping and control materials on a slab (pad), avoiding microbial contamination. Apply the materials to the pulp wound without pressure. Restore the cavity with either a polyacid-modified resin-based composite or a resin-modified glass ionomer cement. This should be followed by an adhesively bonded resin-based composite restoration. The species selected should be the lowest required to satisfy the scientific objective at the lowest animal welfare cost. The choice of species shall be justified and documented. If monkeys, dogs or miniature pigs are used, at least two animals should be used for each time period. If ferrets are used, at least four animals should be used for each time period, as only the canines are suitable. NOTE 1 A mineral trioxide aggregate (MTA) is an appropriate reference control. To prevent washing out of the MTA after placement as it is a non-setting material apply a light curing RMGI material to the MTA and 0.5-1mm surrounding dentin. Restore to final contour using an acid etch/dentin bonding agent/resin composite. 6.5.3.2.4 6.5.3.3 Observe and manage the animals as described in 6.4.3.2.4. Preparation of slides After (25 􏰀 5) days and (70 􏰀 5) days, euthanize with an overdose of anaesthetic, or by applying other generally accepted substances. a sufficient number of animals to provide at least ten teeth containing test material. Examine the restorations, the teeth and their supporting tissues and record details of any abnormalities. Remove each treated tooth, together with its surrounding hard and soft tissues, in a single block and fix in a suitable fixing agent. NOTE Vascular perfusion of the tissues with fixative at the time of sacrifice prior to their removal provides better fixation (See 6.4.3.4). 6.5.3.3.2 After fixation, take a radiograph of each tissue block to determine whether radiographic changes have occurred. Prepare sections for examination as in 6.4.3.3.2. 6.5.3.3.1 15

6.5.3.4 Assessment of dental pulp Examine the sections, describe the histological features, grade the inflammatory infiltrate and calculate the index of inflammatory response according to the protocol described in 6.4.3.4. As the superficial pulp tissue will have been destroyed in creating the pulpal exposure, prepare a single grading of the inflammatory infiltrate, using the scale specified in Table 8. Table 8 — Grading scale for the pulp capping test Grade of inflammation  Description of inflammatory changes 0 No inflammation 1 Mild inflammation: scattered inflammatory cells in the pulp tissue adjacent to the pulpal exposure 2 Moderate inflammation: inflammatory cells with small focal groupings in the pulp tissue adjacent to the pulpal exposure 3 Severe inflammation: extensive inflammatory cell infiltration in the pulp tissue adjacent to the pulpal exposure 4 Abscess formation or extended inflammatory cell infiltration not limited only to the pulp tissue adjacent to the pulpal exposure In addition, a full description of the extent, distribution and the nature of any dentin bridge shall be provided, paying particular attention to the presence of tunnel defects and cellular inclusions which may interfere with the effectiveness of the bridge as a barrier. Grade the degree of bridging of the exposure by tertiary dentin on a scale of none, partial or complete. Guidance on the interpretation of the histological features of dentin bridging is provided in the note below. NOTE The extent and distribution of any dentin bridge should be considered in terms of whether it completely bridges the pulpal exposure site, its depth or thickness and also, its distribution in relation to the site of exposure. An incomplete bridge does not provide effective protection to the exposed pulp. While an adequate depth of bridge is required for effective pulpal protection, uncontrolled reparative dentinogenesis for bridge formation may cause occlusion of the pulp chamber and compromise the vitality of the pulp. Widespread reparative dentinogenesis beyond the local confines of the dentin bridge and its tubular communication with the material may be suggestive of a cellular response to injury (e.g. surgical injury) beyond the direct response to the material. The regularity of the tubular structure in the dentin bridge can be informative of the degree of dysplasia during its formation with absence or the presence of few tubules suggesting more dysplastic tissue formation. The presence of tunnel defects and cellular inclusions in the dentin bridge are also indicative of dysplastic tissue formation and may impact on the permeability and degree of seal that the bridge can provide. 6.5.4 Assessment of results Assess the results as in 6.4.4, including statistical analysis of results. 6.5.5 Test report Submit the results in a test report as in 6.4.5.

Thank you sir for an elaborate information. I am working on developing new dental ceramics funded by DBT India . So far researchers have tested biocompatibility on mouse L 929 fibroblasts as invitro testing. My point is ideally dental materials must be tested on dentin/ huma n gingiva  .. invitro which is more relevant to clinical situation.So am I right  with my viewpoint ?

I am on the hunt for odontoblast cell lines... to test the material?  Is it possible to procure?

I cannot help you with odontoblasts but I attach a file  that may be helpful. If you are testing ceramics it will be in contact with soft tissues (mucosa) and perhaps bone depending on its use. If the ceramic tested is for use in crowns then strictly speaking you need to test the cement that is used for luting he crown and the reaction to odontoblasts. (See the technique described in the attached file). Please note that the ANSI/ADA Spec #41 is similar but not exactly the same a the ISO 7405. We are working  on similar tests and techniques to synchronize the 2 documents.

thank you so much sir.. great information !!!

Look up ANSI/ADA Specification #41 or ISO 7405. Make sure you use the latest guideline, which can only be found in the Spec.#41.

I am working with MDPC-23 mouse cell line. And now doing primary cultures from mouse, after doing a differentiation of pulp cells to odontoblast-like cells. If you want to share some results i will be happy.