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Rather easy to perform, pulpotomy of the deciduous teeth is the most frequent endodontic treatment performed on children, but also the most controversial. Based on the amputation of the pulp chamber and the conservation of the inflammation-free root canals, the clinical results can be good, depending on the materials used. In this, calcium hydroxide (Ca(OH)2) as well as zinc-oxide-eugenol (ZOE) have been proven very inflammatory whereas Formocresol (FC) remains the reference even if its clinical toxicity is still reported in literature on a very controversial way. Nevertheless, this was sufficient to trigger and stimulate a search for alternatives, and led to the proposition to use ferric sulfate and even more recently MTA as new bases for the treatment of the pulp stumps after pulp chamber amputation.

When bioactive molecules such as bone sialoprotein (BSP), bone morphogenetic protein-7 (BMP-7, also termed OP-1) and chondrogenic Inducing Agents (CIA, A+4 and A-4) were implanted in the pulp of the first upper molars, mineralizations were induced. They were either limited to the formation of a reparative dentinal bridge closing the pulpal wound (CIA A+4), or filled the mesial part of the coronal pulp (BSP), or filled totally the pulp located in the root canal (BMP-7 and CIA A-4). Consequently, these molecules may change in the next future the every day practice in dentistry.

A direct or indirect effect of the intake of medication on the pulp itself has not yet been described in the literature. The effect of local anesthetics on the pulp, on the other hand, has been documented. Although local anaesthesia has been employed in dentistry for many years, most investigations of its action have only considered the effect on the nerves within the pulp using traditional methods. Recently it has become clear that the nerves and blood vessels of the pulp do not act in isolation but are closely related. In this respect it has been shown that there exists a direct relationship between the length of the flow cessation and the concentration of vasoconstrictor used. Therefore care should be taken when using vasoconstrictors especially where pulpal injury is apt to occur when dental procedures such as full crown preparations are performed immediately following a ligamental injection. The anaesthetic efficacy of intraosseous injection is well documented. The effect, however, on the dental pulpal circulation still remains subject of further investigation. Radiotherapy involving the oral cavity and salivary glands and chemotherapy (in a lesser degree) induce alterations in the oral tissues and the salivary gland functions. Some of these side effects are transient. However there are side effects such as the xerostomia which are very drastic for the dentition resulting in radiation caries and dental hypersensitivity. Tooth anomalies in the developing dentition are also described. Due to the rapid progression of the radiation caries a monitoring of the oral cavity with strict application of preventive measurements and systematic follow-up can reduce the incidence of the complications. Unfortunately most of the patients belonging to this group consult with the complications of their radiotherapy and chemotherapy. In this respect endodontic treatment of the severely decayed teeth is an important part of dental treatment. Moreover, extraction is regularly contraindicated as osteoradionecrosis is then one of the major sequels.

The smear layer is a direct consequence of instrumentation of the root canal wall. Hand instrumentation as well as ultrasonic instrumentation produce a smear layer on the canal wall. This smear layer is composed of dentine, remnants of pulp tissue and odontoblastic processes and bacteria in an infected canal. Removal of the smear layer is accomplished by the irrigation of root canals with EDTA (17%) followed by NaOCl (5.25%). Permeability of the dentine is increased by the removal of smear layer. In this way the bacteria within the infected tubuli can be more easily destroyed by an intracanal dressing. Whether the removal of smear layer decreases the apical leakage is uncertain. To establish the clinical consequences from removal or preservation of the smear layer, further research is needed.

Pulp tissue may suffer from carious invasion, direct or indirect trauma and last but not least from dental treatment. As the general population grows older and retains longer its dentition, teeth will inevitably experience a complex history of multiple episodes of aggressions. It is therefore not surprising that the dental practitioner is confronted more and more with teeth reacting acutely or chronically (in other words, painfully or not) after proper dental treatment. This paper describes the common pathologic and iatrogenic events that may have an effect on the pulpal health status. Preventive endodontic treatment is to be considered in cases of extensive dental treatment.

Tooth discoloration's may cause serious damage to the aesthetic appearance of the patients. These discoloration's can be treated in several ways but up to lately tooth structure had to be removed in an irreversible manner in order to provide sufficient bulk for the new restorative material. Nowadays thanks to the work of T. Croll and others a method has been established in a scientific way whereby tooth discoloration's confined to the outermost layer of enamel can be removed, through the application of an compound called PREMA which will simultaneous erode and abrade the enamel surface. If carefully selected the discoloration can be removed with only a limited loss of tooth structure. The authors describe the historical background of the method. Furthermore patient's selection, specific instruments and materials are described in detail. The clinical procedure is explained step by step, followed by a complete report of the effects of the procedure on the different tooth structures. Finally the long term results are discussed and the possibility to enhance the result by combining this method with home bleaching.

Bleaching vital and non-vital has now become, for most dentists, a routine treatment. However the use of caustic products is not without risks. This article is a report of several publications that appeared in the endodontic literature cautioning the practitioner. Practical hints are given to reduce the side-effects for the patient.

This in vitro study was designed to ascertain the cytotoxicity of two new dentin systems, Scotchbond MP (3M) and A.R.T. Bond (Coltène), on cultured cell monolayers prepared from fresh explants of human pulp tissue and placed in contact with the materials according to two methods. In a direct method, the two components (primer, adhesive) of each bonding system were placed directly on the cell layers. In an indirect method the bonding agents were placed on dentin slices of 0.3 and 1.0 mm thickness, that were interposed between agents and cells. After 8 days the cytotoxicity was quantitatively assessed by counting of the remaining living cells. The results indicate that the different primer solutions, when placed in direct contact with the cells, are more cytotoxic than the adhesive resins. In indirect contact through dentin, both bonding systems exhibited a similar cytotoxicity. The cytotoxicity appeared to be considerably diminished with a thick dentin slice interposed. These data confirm the role of dentin as a diffusion and buffer membrane for bonding materials. This kind of experiment could in the future improve the correlation between in vitro and in vivo results.

Intraligamentary anesthesia is widely used both as a primary and a supplemental injection technique. The purpose of this review of the literature is to answer questions one may ask about the technique, its efficacy, anesthetic solutions, postinjection discomfort, distribution of the injected solutions, systemic effects and pulpal and periodontal tissue response.

This study was designed to complete the cell culture test for the cytotoxicity assessment of dental material presented by Christen et al. (1989) and Regad et al. (1989). Two liner materials were selected for this experiment which had already been subjected to both in vivo and in vitro tests. After 2, 7 and 14 days of contact with the test materials, the cell responses were evaluated under the light microscope by their growth pattern and morphological aspects. Cell synthesis of fibronectin and type I and III collagen was studied by immunofluorescence. Surface appearance of the cells in contact with the materials as well as their structures were observed by scanning electron microscopy. This study confirmed the viability of the in vitro cytotoxicity assessment methods with cell cultures. The results also demonstrated the potentials of this method in the early screening of dental materials for their biological compatibility.

According to the in vitro and in vivo procedures described by Rockert and Pracros, the effect of different local anesthetics (with and without vaso-constrictive solution) have been studied on rat incisor dental pulp. Histological analysis (optical microscopy) of samples (90 rat incisors) showed: A systematic pulp response with concentrations up to 2%. This response correspond with a toxic reaction on the respiratory activity of pulp cells; A highest response with solutions containing a vaso-constrictor additive; An increasing response according to the nature of the anesthetic solution.

The purpose of this in vitro study was to evaluate the sensibility of frozen human pulp cells, in order to examine the cytotoxicity of dental products. The cell cultures and the biological assessments, using still incomplete human premolars and pulp germs, were achieved according to a standardized method. The sensibility of frozen cells was assessed by comparison of cell reactions before and after 1, 3 and 6 months of congelation, for two dental products called Aquacem and Pulpdent, the cytotoxicity and biocompatibility of which were further confirmed. The behaviour of cells with and without congelation was microscopically evaluated, the growth and morphology of cells were assessed after 7, 14, 21 and 28 days. The comparison of the results showed a similar behaviour between cells with and without congelation, except for few cell alterations in the form of granula which occurred during a short period, probably due to the congelation process. This cell liability offers the opportunity to elaborate a bank of cells available on demand for preliminary cytotoxicity assessments.

The aim of this in vitro study was to assess of the biocompatibility of 6 adhesive dental products (Cavalite, Dual Cement, Fuji Type II, Gluma, Ketac Bond, Scotch Bond) using cell cultures of human pulps and a standardized method. It was thus possible to improve the scale of biological activity proposed by Regad et al., (1989). The specific behaviour of the cells in the contact and adjacent zones has been added to the assessment of the cellular reactions of the whole culture. These criteria allowed the clear differentiation of the toxicity and the biocompatibility of the products. The following estimations were made: Gluma and Fuji Type II "toxic", Cavalite "acceptable", Scotch Bond "not significant", Ketac bond and Dual Cement "acceptable" and "not significant" with a "toxic" tendency.

The biocompatibility of a light curing glass ionomer cement was studied for its pulpal effect when used as a capping agent in a dentin cavity. Pulpal pressure and temperature were recorded in 14 dog canines after placement of the glass ionomer cement. No increase was observed in 12 specimens on 14 samples. These results indicate that no pulpal effect can be demonstrated when using Vitrabond as a dentin capping agent.

The biocompatibility of glass ionomer cement with silver and titanium ions is studied in vivo on dog's canine. Class V cavities, side by side the pulp, are prepared and Ketak Silver cement is placed inside. Variation of pulp pressure are recorded before and after the cement's applying, after which the crowns are cut and broken at the filling level, the different components part diffusion through the dentin are placed in prominent position by means of a microanalysis and a cartography of the sample is obtained by colorimetric picture. The pulp's haemodynamic responses to Ketak Silver are in harmony with the metallic ions diffusion and specially with silver.

A biological model for evaluating pulpo-dentinal capping materials is described. The model uses cultures of human pulp cells which are explanted to form cell monolayers. Four products already tested in vivo on teeth subsequently extracted for orthodontic reasons were laid directly over these cultures and observed after 7, 14, 21 and 28 days, corresponded to the in vivo test periods. The growth and morphology of the cells were similar for both test systems, indicating comparability between the two biological models as well as the validity of the developed in vitro method. A preliminary scale of biological activity is proposed which could be useful for preliminary screening of materials.

A study of the pulpal biocompatibility of the Caridex system was carried out on human premolars to be extracted bilaterally for orthodontic reasons, in 3 volunteers aged 10 to 13 years. A class V cavity was prepared bilaterally on the 2 premolars to be extracted: one of the cavities was washed with Caridex. The other was used as a control. The extractions were made immediately, 4 and 7 weeks after these operative procedures. Histological examinations showed that the Caridex system was biocompatible for the human dental pulp. A comparative study of carious cavities was conducted using light microscopy, Gram stain and transmission electron microscopy on the quality of the cleaning obtained after conventional cavity preparation and use of the Caridex system. After Caridex treatment, the dentinal surface was free of demineralized zones and no smear layer was present. The occasional presence of bacteria was noticed after conventional use of a bur as well as after Caridex. More limited clinical indications of the Caridex system are proposed.

Calcium hydroxide is used in the treatment of different traumatized teeth. New concepts about the effects of calcium hydroxide on vital pulps and immature non vital teeth are developed. Some clinical techniques and their results are described.

Dental pulp was electrically stimulated in the awake rat. When the stimulus intensity was progressively increased the following four nociceptive reactions successively appeared: jaw opening reflex, scratching, head rotation, vocalization. The threshold of these four reactions was observed before and after administration of three antalgic drugs. No action of the three drugs was observed for the jaw opening reflex. However each drug showed different actions on the other three reactions.

The incorporation of labelled hydrocortisone (3H-cortisol) in the dental pulp of Wistar rats has been tested using autoradiography. Light microscopy showed that an hour after injection the hormone is incorporated in the nuclei of the odontoblasts, subodontoblastic and endothelial cells of the dental pulp. It was also demonstrated at the ultrastructural level that a 4 week-treatment with high rates of hydrocortisone (16 and 32 mg/kg) at the time of rat intensive growth induces degeneration of the odontoblasts, pulp connective tissue cells and capillaries. High rates of hydrocortisone thus induces a decrease in the protective and reparative responses of rat molar pulp.

Increasing emphasis is being placed on the use of agents for protection of the pulp and the deep regions of the pulp cavity, modern conservative dentistry attempting as far as possible to conserve pulp vitality. The aim of this report is to assist the dental practitioner in his choice of the different varnishes and cements marketed by dental product manufacturers, to ensure the maximum of benefits for patients' teeth.

Evaluation of the biocompatibility of a crown reconstruction material in vivo on human teeth by histologic observation of pulpal reactions is a long lasting and expensive procedure. Before to start it, a first examination can be done by testing the material on cell cultures. If the used culture cells contain antibiotics, it is necessary to combine these tests with a bacteriologic examination of the tested material. Two calcium hydroxide containing materials for dentin-pulp capping, were submitted to cytotoxicity tests using human pulpal fibroblasts cultures. The cytotoxicity of one over the two materials could be related to its lability and bacterial contamination.