Infected Dentine Revisited

Dentine becomes infected as a result of caries lesion formation on root surfaces and when lesions progress following cavitation of enamel lesions. However, this infection is unimportant because the driving force for lesion formation and progression is the overlying biofilm. This explains why root surface caries can be controlled by mechanical plaque control and fluoride, and restorations are not needed to arrest these lesions. Similarly, the infected dentine in cavitated coronal lesions does not have to be removed to arrest the lesion. If the lesion is either accessible or opened for cleaning by the patient or parent, the lesion can be arrested. Sealing of infected dentine within the tooth, either by a Hall crown in the primary dentition or by partial caries removal prior to placing a well-sealed filling, will also arrest the lesion. When restoring deep lesions in symptomless, vital teeth, vigorous excavation of infected dentine is likely to expose the pulp and make root canal treatment necessary. Thus complete excavation'is not needed and should be avoided. CPD/CLINICAL RELEVANCE: Root surface caries can be arrested by cleaning and fluoride application. Restorations are not essential. Vigorous excavation of softened dentine in deep cavities of symptomless, vital teeth is contra-indicated. It is not needed and increases the risk of pulp exposure.

Endodontic diagnostic terminology update

Determination of the etiology of the patient's chief complaint and a correct diagnosis are paramount prior to a recommendation of endodontic therapy. Reproduction of the patient's chief complaint is critical. If the chief complaint cannot be reproduced, consider consultation with or referral to an endodontist or orofacial pain specialist. The diagnostic terminology presented in this update provides for a more accurate description and communication of the health or pathological conditions of both pulpal and apical tissues. This information is summarized in Table I.

Odontogenic signs and symptoms as predictors of odontogenic infection

BACKGROUND

The authors conducted a study to determine if odontogenic signs and symptoms in the emergency department predicted the development of overt odontogenic infection at a follow-up dental visit.

METHODS

One hundred ninety-five patients with odontalgia, but without overt signs of infection, were enrolled in a prospective, double-blind, randomized clinical trial. Data included dental diagnosis, pain characteristics, presence of caries and restorations, presence and size of periapical radiolucencies and other diagnostic test results.

RESULTS

Thirteen of 134 subjects for whom data were available had signs of infection at the follow-up visit. Subjects in the follow-up infected (FU-I) group had larger baseline radiolucencies than did subjects in the follow-up noninfected (FU-NI) group, and restorations were more prevalent for involved teeth in the FU-I group than in the FU-NI group.

CONCLUSIONS

A relationship exists between radiolucency size and the presence of amalgam restorations in patients who develop clinical signs of infection. Penicillin did not appear to influence this progression.

CLINICAL IMPLICATIONS

Antibiotics are not effective in preventing the development of odontogenic infection when definitive dental therapy cannot be provided for acute pain in the absence of clinical signs of infection. Although the overall risk of developing infection is low, early treatment is indicated for teeth with larger periapical radiolucencies, amalgam restorations or both.

Aetiology, classification and pathogenesis of pulp and periapical disease

At present, the majority of the treatments that are performed in the clinic are due to disease entities involving the dental pulp and periapex. Dental pulp is a richly vascularized and innervated tissue, enclosed by surrounding tissues that are incapable of expanding, such as dentin. It has terminal blood flow and small-gauge circulatory access the periapex. All of these characteristics severely constrain the defensive capacity of the pulp tissue when faced with the different aggressions it may be subjected to. Pulp tissue can also be affected by a retrograde infection, arising from the secondary canaliculi, from the periodontal ligament or from the apex during the course of periodontitis. Due to the fact that periapical disease is almost inevitably preceded by pulp disease, we shall begin by describing the causes of pulp disease and will then proceed to a discussion of the causes of periapical disease. The course of illness and classification of these pathological entities will depend on the aetiology involved. We will analyse pulp necrosis and pulp degeneration that are capable of triggering reversible apical periodontitis or irreversible apical periodontitis.

Direct capping of human pulps with a dentin bonding system or with calcium hydroxide cement

OBJECTIVE

To study human pulp reactions to direct cappings with a dentin adhesive compared with a calcium hydroxide cement, especially with respect to formation of hard tissue in the exposure site.

STUDY DESIGN

Direct pulp cappings were made in 34 caries-free premolars scheduled for extraction due to orthodontic treatment. Half of the teeth were capped with a dentin adhesive, the other half with a calcium hydroxide cement. After periods of from 7 to 70 days, the teeth were extracted and processed for light microscopical examination.

RESULTS

No postoperative sensitivity was experienced. A slight inflammatory reaction was seen in both groups in the short observation period. In the long observation period, significantly more "dentin bridging" was seen in the calcium hydroxide group than in the dentin adhesive group (P < .05).

CONCLUSION

The findings from the present limited material is in accordance with previous findings from human studies and contraindicate use of dentin adhesives for direct pulp capping.

Pulpal response to a fluoride-releasing all-in-one resin bonding system

Pulp tissue reactions to a fluoride-releasing all-in-one resin bonding system (Reactmer Bond and Reactmer Paste) in non-exposed monkey teeth were histopathologically evaluated at three, 30, and 90 days after restoration. No serious inflammatory reactions of the pulp, such as necrosis or abscess formation, were observed. At 90 days in the Reactmer group, odontoblastic change and inflammatory cell infiltration were not observed, and slight irritation dentin formation was formed. The pulpal response of the Reactmer group was minimally different from that of the control group. Consequently, the Reactmer system was determined as being biologically compatible with vital pulps.

Histopathology of the pulp of primary molars with active and arrested dentinal caries

The purpose of this study was to compare the histological appearance of the pulp of human primary molars with active and arrested lesions. The sample consisted of 36 primary molars (18 with active lesions and 18 with arrested lesions) extracted from 35 children between 5 to 9 years of age. The histological diagnosis was classified in normal pulp, transitional stage, partial pulpitis, total pulpitis and total necrosis, and then subdivided in three subgroups: treatable, untreatable and questionable. Results showed that normal pulp or transitional stage (treatable category) was diagnosed in 50% of teeth with arrested lesions, compared to 11.1% of teeth with active lesions. Partial pulpitis (questionable category) was present in 38.8% with arrested lesions compared to 22.2% with active lesions. Total pulpitis and total necrosis (untreatable category) was diagnosed in 11.2% with arrested lesions compared to 66.7% with active lesions. The observed frequencies of histological categories between both groups were statistically significant (P < 0.05). Histologically, pulp reaction under active and arrested lesions in primary molars revealed the formation of a basophilic calcio-traumatic line at the junction of the primary and reparative dentin, formation of reparative dentin and a regular odontoblastic layer in 60% of the cases. Results indicated that the type of lesion (active or arrested) is a good indicator of the histological status of the pulp.

Pulpal evaluation of two adhesive systems in rat teeth

Formocresol is the agent most frequently used with pulpotomies in primary teeth, but its use is currently under discussion in regard to its possible toxic effects. Some current works suggest the use of dentinal adhesives in cavities with minimal dentinal thickness and even in small pulpal exposures. Our objective was to evaluate pulpal response to the application of two dentinal adhesives Syntac and Prime & Bond NT in pulpal exposures in rat teeth. Sprague Dawley rats were used, male, 150 to 200 gm in weight. The maxillary first molar, left and right, was employed in each case, a total of twelve teeth. Duration of the study was 45 days. Sections were evaluated using a light microscope in order to determine pulpal response to the two adhesives. In both groups the persistence of chronic inflammation was associated with the absence of dentinal bridges in the affected specimens. Areas of necrosis and absence of regularity of the odontoblastic layer could also be seen.

Determination of endotoxins in the vital pulp of human carious teeth: association with pulpal pain

OBJECTIVES

The aims of this investigation were to determine the presence or absence of endotoxins in the pulp of symptomatic and symptom-free human carious teeth, to quantify the amount of endotoxins present, and to associate the presence of endotoxins with the acute pulpal pain.

MATERIAL AND METHODS

Pulpal tissue was sampled from 28 single-rooted carious teeth (15 symptomatic, 13 symptom-free) derived from 28 patients. Samples were also taken from the pulp of 5 noncarious control teeth. During sampling an effort was made to collect an equal weight of pulpal tissue in all cases (approximately 8 mg). The extraction of endotoxins was performed with the use of phenol-water. The assay and quantitative determination of endotoxins was performed with the use of a limulus lysate test. The data were analyzed statistically by using the independent t test.

RESULTS

Endotoxins were detected in pulpal tissues of all carious teeth in the symptomatic (mean average, 0.15773 ng/mL; SD = 0.045811) and symptom-free group (mean average, 0.10723 ng/mL; SD = 0.010925). In noncarious control teeth, endotoxins were not detected. The presence of endotoxins was significantly higher in the group of symptomatic teeth than in the group of symptom-free teeth (P <.001).

CONCLUSIONS

The presence of endotoxins in the pulpal tissue of all the carious teeth indicates that they may play a major role in the pathogenesis of human pulpal diseases. Since a significantly higher level of endotoxins was detected in the pulp of symptomatic carious teeth than in that of symptom-free carious teeth, an association of endotoxins levels with severity of pulpal pain is probable.

Pulpal response to prolonged dentinal exposure to sodium hypochlorite

AIM

The aim of this study was to examine the effect of undiluted NaOCl on vital pulp tissue when applied to freshly cut dentine.

METHODOLOGY

Class V cavities were prepared to a depth of 2 mm in 20 teeth in four Beagle dogs. The cavities on one side of each dog were irrigated continuously for 5 min with 5.25% NaOCl, whilst the cavities on the opposite side in each dog were irrigated with saline for the same length of time. Prior to filling each cavity with Cavit, they were again rinsed with saline and gently dried with an air stream. The dogs were sacrificed to allow for investigation of pulpal conditions under the cavities after periods of 24 h, 1 week, and 4 weeks. Histological preparations were made and stained with H & E for evaluation of the pulp subjacent to each cavity. The tissues were examined for presence of inflammatory cells and categorized as (i) no inflammation, (ii) mild, (iii) moderate, and (iv) severe inflammation.

RESULTS

The six teeth in the 24 h observation group all showed mild inflammation, both in the NaOCl and the saline groups. After 1 week and 4 weeks, the pulps from all the teeth were free of inflammatory cells.

CONCLUSION

Under the conditions of this experiment, the use of NaOCl in a freshly cut cavity in an intact tooth of a dog, with exposed dentinal tubules, does not appear to cause additional pulpal damage to that caused by the physical contact in cutting tooth structure.

Current practice in endodontics: 2. Diagnosis and treatment planning

The aim of this series of six articles is to improve the quality of endodontic treatment in general dental practice by considering what is currently being taught in dental schools. This second article considers the accurate diagnosis of endodontic lesions, which frequently present as emergencies requiring prompt, rapid and efficient attention. The paper then presents the treatment normally indicated once a correct and accurate diagnosis has been made.

Reversible And Irreversible Painful Pulpitides: Diagnosis And Treatment

The foregoing clinical evidence indicates that when pain is severe, or when mild to moderate pain is present with a previous history of pain in the aching tooth, with or without periapical radiolucency, the tooth is in the IRPP category. Treatment dictates endodontic therapy or extraction. On the other hand, when clinical evidence indicates that the pain is mild or moderate with no previous history of pain, normal pulp vitality, and there is no positive percussion sign, the pulp is in the RPP category. Treatment dictates indirect or direct pulp capping in teeth with or without periapical radiolucency. The success rate favours teeth with no periapical radiolucency, 98%; in teeth with periapical radiolucency the success rate is less favorable, 43%. Efforts should be made to maintain pulp vitality. Endodontic therapy can always be done, if in time the pulp develops necrosis.

Morphometric analysis of teeth with inflamed pulp

The most common method of evaluating pulp tissue reactions to injury is by a qualitative assessment of pulp tissue alterations. This evaluation method is subjective and difficult to quantify; stereological methods are more suitable, for they can quantify important tissue components, and so more objectively describe pulp tissues. This study compares a morphometric and a descriptive method of classification for pulp tissue analysis by using 15 teeth with inflamed pulp tissue, and 12 teeth experimentally pulp-capped with calcium hydroxide. Morphometric analysis allowed for volumes of remaining dentin, pulp tissue, inflamed pulp tissue, and reparative dentin to be calculated. In addition, volume densities of polymorphonuclear and mononuclear leukocytes, odontoblasts, fibroblasts, erythrocytes, vessels, and residual tissue were calculated for comparison among different experimental teeth. The morphometric method provided a quantitative description of tissue reactions. The descriptive method of classification was adequate when inflamed tissue subjacent to the cavity was evaluated, but was less precise than the morphometric method in describing reactions deeper in the tissue. The descriptive method could delineate the amounts and types of inflammatory cells only in non-quantified terms, while the morphometric method could quantify and locate them. It also yielded a quantified evaluation of the healing sequence of experimentally pulp-capped teeth. In conclusion, a morphometric method can yield more quantitative data on pulp tissue reactions than can a descriptive method of classification.

Classification and diagnosis of pulpal pathoses

The purpose of this article has been to review some concepts regarding the histophysiology and histopathology of the pulpodentinal complex and the "language of classification." Although there may not be agreement on the "language" presented here, there can be no disagreement that from a clinical perspective, knowledge and appreciation of the ideas presented can be helpful in determining pathologic presence. In reaching the ultimate clinical decision, the following questions must be answered: Are we dealing with a pulpal disease that is potentially reversible? If treatment is necessary do we treat the pulp or the pulp canal?

[Dental pulp diseases of the deciduous teeth. II. Clinical classification]

Clinical and pathomorphological studies of various pulpal affections in 55 deciduous molars from children aged between 2.5 and 8 years call in question the clinical appropriateness of the current classification of pulpal affections that makes use of the pathohistological nomenclautre. In this paper, a classification is suggested that is based on clinical symptoms and allows for current methods of therapy.

[Pulp diseases in the deciduous teeth. I. Histopathological changes (correlation between microscopic picture and clinical diagnosis)]

Clinical and histopathological examinations of 85 deciduous molars from children aged between 2.5 and 8 years show considerable disagreement between the microscopical picture and the clinical diagnosis according to the classification of WILGA. This calls in question the appropriateness of the histopathological classification for clinical diagnosis. For this reason, the present study was undertaken to elaborate a new classification of pulpal affections in the deciduous dentition with special regard to the various clinical pictures.

[Experimental allergic pulpitis in rabbits]

Ten male, albino rabbits, weighing about 2,5 kg, were sensitized with 0.05% of 1-chloro-2,4-dinitrobenzene (DNCB) in complete Freund's adjuvant. Ten controls received the complete Freund's adjuvant only. Fourteen days later, the animals were submitted to a dental test. The four incisor pulps were exposed under general anesthesia. A sterile cotton pellet with 10-(-4) mg of DNCB was sealed inside the cavity. A skin test was also performed with 0.1% DNCB. The operative trauma was evaluated on five additional control animals. Twenty four hours after the challenge, the animals were killed and their teeth were studied histologically. Three different pulpitis were observed: 1) in animals without DNCB, a traumatic pulpitis with a mild focal necrosis and serous infiltrate; 2) a toxic pulpitis induced by the DNCB in the controls. They were killed and their teeth were studied histologically. Three different kinds of pulpitis induced in sensitized animals. A considerable necrosis is present close to the pulp exposure. This pulpitis is characterized by a marked serous exudate and by an accumulation of lymphocytes, eosinophils and macrophages, either perivascularly or in the pulpal mesenchyme. A modification of the present classification of pulpitis is proposed.

Endodontic classification

Clinical and histopathologic findings are mixed in current endodontic classifications. A new system, based on symptomatology, may be more useful in clincial practice. The classifications are vital asymptomatic, hypersensitive dentin, inflamed-reversible, inflamed/dengenerating without area-irreversible, inflamed/degenerating with area-irreversible, necrotic without area, and necrotic with area.

Effect of bacterial products on inflammatory reactions in the dental pulp

Culture filtrates (extracellular components) and material obtained from disintegrated cells (intracellular components) of cultured plaque bacteria were studied for their capacity to induce inflammatory reactions in the dental pulp. Class V cavities were prepared on the buccal surface of 94 teeth: 42 test and 52 control teeth in six adult monkeys. lyophilized bacterial components were sealed into the test cavities either alone or following an 8-h topical application of a solution of the same components in phosphate-buffered saline (PBS). Culture medium and PBS were applied in two sets of control cavities. A third set was restored with zinc oxide-eugenol cement. The animals were killed 32 h after the initiation of the experiment and the pulps were examined histologically. Teeth treated trophil leukocytes in the area of the pulp subjacent to the cut dentin tubules. Abscess formation was frequently found. The severe reactions which developed were independent of differences between individual animals and differences in thickness of the remaining dentin. The controls showed damage to the odontoblasts but little or no neutrophil infiltration. The findings confirm that products of bacteria applied to exposed dentin initiate inflammatory reactions in the dental pulp.