Pulpal Reactions Research Articles

Replantation of avulsed teeth with immature root development

Successful treatment of the avulsed tooth with immature root development is dependent on both pulpal and periodontal responses. The pulpal reaction is often one of revascularization with subsequent replacement of the necrotic pulp tissue. Continued root development and further calcification of the existing root structure are often seen with revitalization. The periodontal response to avulsion is dependent on the vitality of the periodontal ligament cells on the root surface. Normal healing occurs when the vitality is maintained, while replacement resorption results when the vitality is lost. Replantation after a short extra-alveolar period appears to provide the best prognosis for long-term retention of the avulsed tooth.

Histometric evaluation of odontoblast responses to Nobetec and Super Syntrex.

Abstract A reproducible method to determine reduction in odontoblast number and variation in dentine thickness was devised. Using this method the pulp reaction patterns to Nobetec® (a modified zinc oxide‐eugenol cement) and Super Syntrex® (a silicate cement) in verve I monkeys were quantitated. This investigation showed that statistically significant reductions in odontoblast numbers were seen under cut dentinal tubules compared lo areas under a cavity with no cut tubules. Reparative dentine thickness was similar under both materials and the mean thickness doubled between 28 and 56 clays after cavity preparation. Both materials were (bund lo be irritant. It is suggested that quantitation of odontoblasts and reparative dentine thickness under cut dentinal tubules may be used as (he main criteria in pulpal studies in order to discriminate between test materials.

Pulpal response to the topical application of citric acid following root planing in cats

The purpose of this study was to evaluate the pulpal reaction to topically applied citric acid (pH 1.0) following root planing procedures. Full-thickness mucoperiosteal flaps were reflected over the maxillary canines in six cats. The cervical portion of the buccal root surface was root planed and treated for 3 min with either citric acid (pH 1.0) or saline. The animals were killed after 3 days and block sections of the teeth obtained. Buccolingual serial sections of the teeth were prepared and evaluated for odontoblastic and inflammatory changes. Histological examination revealed normal pulpal structures in all experimental and control specimens.

The pulpal response to citric acid in cats.

Citric acid conditioning of dentine has been proposed as an efficacious treatment for promoting re-attachment after periodontal surgery. This study investigated the pulpal reactions to periodontal surgery combined with citric acid (pH 1) demineralization of exposed dentine for 3 min. 9 cats were used as the experimental animals, with each cat providing 1 negative and 1 positive control and 2 experimental canine teeth. Evaluation was over 3 observation periods, with 3 cats in each period being sacrificed at 4, 21 and 83 days. Positive control teeth, which underwent periodontal surgery combining the removal of approximately 3 mm2 of labial bone and vigorous root planning of the exposed root surfaces, displayed mild to moderate pulpal reactions during the short- and intermediate-term periods and only mild to no reactions in the long-term period. The addition of citric acid demineralization, however, resulted in 5 experimental teeth (28%) becoming abscessed or totally necrotic in the intermediate- and long-term periods. At 21 days, the frequency of adverse pulpal responses to surgery and citric acid conditioning was significantly (p less than 0.05) greater than to surgery alone. Although 4 experimental teeth were relatively uninflamed at the long-term period of observation, all showed irritational dentine formation. Penetration of exposed dentinal tubules by plaque bacteria was observed only in the citric acid treated teeth.

Pulpal reaction and protection with preventive dental materials propertised tannin-fluoride

Pulpal reaction and protection with preventive dental materials propertised tannin-fluoride

Human pulpal reaction to the Modified McInnesBleaching Technique

Thirty-six human teeth were examined to determinehistologically if the Modified McInnes Bleaching Technique had any adverse effects on the pulp. Under the conditions of this study, there were no significant pulpal reactions to the bleaching technique even when a substantial amount of the enamel was removed from the facial surface of the crowns. Thirty-six human teeth were examined to determinehistologically if the Modified McInnes Bleaching Technique had any adverse effects on the pulp. Under the conditions of this study, there were no significant pulpal reactions to the bleaching technique even when a substantial amount of the enamel was removed from the facial surface of the crowns.

Biologic Considerations in the Selection and Use of Restorative Materials

In this article the defense mechanisms of the pulp and pulp reactions to injury were briefly reviewed. Iatrogenic pulp injury was emphasized and guidelines for prevention of such injury were provided. These could be summarized as follows: Never cut dry. Always use a water coolant to prevent heat generation and desiccation of dentin. Use a protective base or liner with materials that are known to be irritating to the pulp (groups II and III) regardless of cavity depth. Use a protective base in all deep cavities where the possibility of a microscopic exposure of the pulp exists, regardless of the nature of the material to be used for restoration.

Pulp reactions to experimental exposures in young permanent monkey teeth.

Exposures of the dental pulp complicate the treatment of fractured teeth. If the root formation is incomplete, the choice of treatment rests between pulp capping and pulpotomy; alternatively pulpectomy and conventional root therapy must be carried out. Treatment planning is dependent on the clinical assessment of the degree of pulp damage and the extent of the pulp inflam- mation. Invariably, the time lapse between pulp exposure and treatment may amount to several hours and even to days. Experi- mental studies on rats, dogs and monkeys

Follow-up study of permanent incisors with complicated crown fractures after acute trauma.

Complicated fractures occur in 3.5% of acute traumatized incisors. A pulp exposure results in almost all cases in endodontic treatment. The present investigation evaluated the prognosis for the different types of endodontic treatments following complicated crown fractures. Only incisors with an observation period of more than 23 months are included; the material comprises 301 incisors. Pulp capping was successful in 90.5% of the cases. There was a clear tendency for a positive correlation between the stage of the root development and the success rate of the endodontic treatment. In cases with pulpotomy ZnO/eugenol cement or calcium hydroxide was used as amputation material. The pulp reactions following the different treatments are discussed. If calcium hydroxide was used 90% was successful, while in cases with ZnO/eugenol cement as amputation material 8.9% developed necrosis of the pulp and 34.4% showed an undesirable reaction with formation of hard tissue barrier or obliteration. The healing frequency was 83.9% for teeth treated with pulpectomy but there was a clear correlation between the standard of the root filling and the success rate. For all three treatment groups there was a correlation between damage to the supportive tissue and treatment success.

Migration of leukocytes in dental pulp in response to plaque bacteria.

Cell material from three different dental plaque bacteria (Actinomyces viscosus, Streptococcus mitis, Actinobacillus actinomycetemcomitans) were studied for their capacity to induce leukocyte migration in the dental pulp of monkeys. Altogether five animals were used to provide 123 teeth for the study. The bacterial test materials were prepared from lyophilized sonicates of pure cultures of respective bacteria mixed with crystalline bovine serum albumin (BSA) 1:1 by weight. Immediately prior to use in the experiment saline was added to render the test material into a paste-like consistency. Buccal Class V cavities were prepared in the monkey teeth leaving a thin remaining wall to the pulp. In these cavities, the test materials were enclosed for a period of 8 h. A set of control cavities received BSA alone. Placement of test and control materials were made before and after depleting the animals of serum complement by repeated injections of Cobra Venom Factor. Histologic examination of pulp tissue specimens showed that materials from two of the bacterial species (A. viscosus, Act. actinomycetemcomitans) consistently induced infiltrations of polymorphonuclear leukocytes in one to several cell layers underneath the test cavity. The material from S. mitis seemed less potent and in 11 of 22 teeth no pulpal reaction was recorded. Inactivation of complement with Cobra Venom Factor did not appear to affect the severity of the pulpal responses.

Pulp reactions to exposure after experimental crown fractures or grinding in adult monkeys

Pulp reactions to exposure after experimental crown fractures or grinding in adult monkeys

Pulpal reaction to bleaching of teeth in dogs.

Hydrogen peroxide and heat are two components of a technique commonly used to bleach human teeth. The effects of these two components on pulp tissue of dog teeth were evaluated histologically. Hydrogen peroxide alone or with heat caused obliteration of odontoblasts, hemorrhage, resorption, and inflammatory infiltration, while heat alone was not detrimental. Pulpal changes demonstrated evidence of reversibility after 60 d.

Reaction of the exposed pulps to new cements containing calcium hydroxide

The biologic properties of three newly developed cements containing calcium hydroxide were evaluated and compared with those of polycarboxylate cement and Dycal by application of the cements in direct contact with rat pulps. The newly developed cements were biologically acceptable and induced pulpal healing by formation of secondary dentin. Dycal elicited mild pulp inflammation, followed by slow dentin formation. Although polycarboxylate cement induced a very mild pulpal reaction, healing took place via the formation of thin irregular, poorly formed dentin bridges over a long period.

Pulpal response to an epimine plastic

Pulpal reactions to three dental materials, Scutan, a self-curing resin, and zinc oxide-eugenol cement, were comparable. The pulpal reactions to Scutan appeared to be milder than those to a self-curing resin or to zinc oxide-eugenol cement.

Pulp reaction to a tricalcium phosphate ceramic capping agent

A porous form of tricalcium phosphate ceramic has been shown to stimulate new bone formation around the implant. The purpose of the present study was to evaluate this material in a powder form as a pulp-capping material. It was found difficult to cover a pulp exposure adequately with Synthos ceramic powder alone. Histologic sections showed dentinogenesis around those particles which were forced into the pulp proper, demonstrating the nonirritating potential of Synthos. Because of the bacterial infection in so many of the specimens, this study is inconclusive with respect to the use of this material as a capping agent. A similar study, employing a rubber dam to protect the exposure, is recommended.

Bacteria and pulpal reactions under silicate cement restorations

Silicate cement was inserted in deep unlined cavities in 70 human teeth; 35 cavities were cleaned with an antibacterial cleanser, and the other 35 cavities in the contralateral teeth were treated with water spray only. In all teeth, invasion of bacteria from the tooth surface was prevented with a surface seal. Histologic examinations after 4 weeks revealed bacterial growth on dentinal walls in 9 of the uncleaned and in 2 cleaned cavities. Only in these 11 teeth was an inflammatory reaction seen in the pulp. Under eight cavities without bacterial growth and with silicate cement placed directly on an exposed pulp, no serious injury and no inflammatory reactions were observed. It was concluded that silicate cement per se does not seriously irritate the pulp. Infection of cavity walls should be avoided, not only by removing grinding debris and antibacterial cleansing, but also by use of a liner to prevent invasion of bacteria from the surface of the tooth.

On Possible Chromophoric Structures in Wood And Pulpsa Survey of the Present State of Knowledge

Abstract Wood is a complex and inhomogeneous macromolecular system made up of cellulose, hemicelluloses, lignin, mineral matter, and extractives. Most woods are relatively light in color, but all contain some coloring components. Within these, knowledge of the nature of chromophoric groups is still meager. Casey [1] claimed that almost every pulp component or reaction product is accused of being the carrier of chromophores. While it is generally conceded that the major contributor of color is the lignin component [2], it cannot be precluded that cellulose is not contributing also. In some species the extractives become the controlling factor [3–6]. Color reactions of lignin are a main subject of many textbooks [7–12].

Effect of experimentally induced marginal periodontitis and periodontal scaling on the dental pulp.

Experimental breakdown of the periodontal attachment apparatus was produced in six young adult monkeys to study the effect on the tissue of the dental pulp by (1) periodontitis, (2) scaling and plaque accumulation on exposed root dentin. Periodontal tissue breakdown was induced by the placement of ligatures around the neck of 92 permanent teeth. Subsequent plaque formation caused marked loss of periodontal tissue support, which after a period of 5--7 months amounted to 30--40% of the root length. One group of teeth received no further treatment. Other teeth were subjected to scaling and root planing. Following treatment, plaque was allowed to accumulate for 2, 10, and 30 days on the freshly planed root dentin surfaces. Histologic examination revealed that in comparison to teeth with normal periodontal conditions, 57% of the teeth exposed to periodontitis exhibited pathologic pulp tissue alterations. Secondary dentin formation and/or inflammatory cell infiltrates were observed within localized areas of the pulp subjacent to root surfaces exposed to periodontal tissue destruction. The changes within the pulp were of "mild" nature and only one tooth displayed signs of total pulp necrosis. Lateral canals communicating with both the pulp cavity and the exposed root surface were never detected. Teeth subjected to scaling and subsequent plaque accumulation in comparison with teeth with periodontitis alone exhibited no obvious aggravation or increased incidence of pathologic pulp reactions. The findings show that in the monkey (1) periodontal destruction limited to the cervical half of the root and (2) plaque accumulation on exposed root dentin does not cause severe alteration in the pulp of the roots involved.

Dental pulp reaction to Cavit temporary filling material

Seventy-two teeth in three Macaque fasicularis monkeys were used to evaluate pulpal response to Cavit. Displacement of odontoblastic nuclei was evaluated histologically at three time periods in order to identify initial, early, and final responses. There were no statistically significant differences in pulpal response between Cavit and the zinc oxide-eugenol controls when used in accordance with the manufacturer's directions.

The pulp. A big issue about a little tissue.

Difficulties in correlating pulp symptomology with available histopathological and biochemical data have hampered understanding of pulp reaction to stimuli. Some of the less well known biochemical cell and tissue regulatory systems are appraised. Pathways whereby such systems could be implicated in pulp function are suggested.