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.

Histological comparison of pulpal inflammation in primary teeth with occlusal or proximal caries.

OBJECTIVE: A number of clinical and histological studies have investigated caries-related changes in the primary tooth pulp, but the effect of caries site, as a clinical variable, has not been previously considered. This study sought to compare inflammatory changes within the pulp of primary molars according to the location of the caries lesion (occlusal or proximal). METHODS: Eighty-three primary molars were extracted under general anaesthesia for caries and/or orthodontic reasons, and were split immediately after removal and fixed in 10% formalin. Teeth were then decalcified, sectioned, and stained with haematoxylin and eosin for histological examination using light microscopy. Caries depth was measured using a graticle, and the site of the caries lesion noted as occlusal or proximal. Samples were further classified into one of five subgroups according to the observed degree of pulpal inflammation. RESULTS: Key findings were that where caries depth was less than 50% of the total dentine thickness, there were no significant differences in inflammatory status according to caries site. In contrast, marked inflammatory changes were significantly more likely throughout the coronal pulp of teeth with proximal caries compared to teeth with occlusal caries where caries depth was equal to, or greater than, 50% of the total dentine thickness (P = 0.017, Fisher's exact test). CONCLUSION: Primary teeth with proximal carious lesions extending more than 50% through the dentine thickness appear to have more extensive inflammatory pulpal changes than teeth with occlusal caries of a similar depth. This finding has clinical implications and may help inform treatment decisions in the management of primary teeth with deep carious lesions.

Odontogenic signs and symptoms as predictors of odontogenic infection: a clinical trial.

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.

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.

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.

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.

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.

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.

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?

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.

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.

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.

Application of high-frequency radio waves to direct pulp capping.

INTRODUCTION: In vital pulp therapy such as direct pulp capping, clinical success rates depend on achieving hemostasis in exposed pulp tissue. For hemostasis of exposed pulp tissue, gentle pressure by cotton pellets moistened with sodium hypochlorite is most commonly used. However, more rapid and reliable methods are necessary. Therefore, we focused on high-frequency radio waves (HRW). METHODS: To evaluate reparative dentin induction by HRW, we used a rat direct pulp capping model and performed hemostasis by using HRW of several strengths, covering the pulp with calcium hydroxide as a direct capping agent. After 14 or 28 days, rats were killed, and reparative dentin and pulp inflammation were investigated histologically. RESULTS: Radio wave-induced hemostasis required less time when compared with the control group. Reparative dentin with regularly arranged dentinal tubules was observed in the HRW group. CONCLUSIONS: HRW induce hemostasis and produce high-quality reparative dentin and reduced pulpal inflammation.

Osteocalcin expression in pulp inflammation.

INTRODUCTION: Dental pulp inflammation and repair are closely related. Osteocalcin (OCN), a glycoprotein present in dentin matrix, is expressed by odontoblasts. Although OCN is considered a reparative molecule inside the dental pulp, it is not clear if it is involved in pulpal inflammation. The objective of this study was to localize OCN in reversible and irreversible pulpitis and to describe its possible function in inflammation. METHODS: Pulp tissues in the form of reversible and irreversible pulpitis were collected from the endodontic clinic. Those from impacted teeth were used as controls. Immunohistochemistry was used to localize OCN. Samples were analyzed for OCN and inflammatory mediator expression using multiplex assay. RESULTS: OCN in inflamed tissues was localized in cells and matrix around calcification areas and in cells around blood vessels but not in normal tissues. The plex assay (Bio-Plex 200, Bio-Rad Laboratories Ltd, Mississauga, ON, Canada) showed OCN expression in reversible pulpitis significantly higher than in irreversible pulpitis, and both were significantly higher than in the controls. A panel of inflammatory mediators showed an increase in reversible and irreversible pulpitis. Another panel was decreased in both stages compared with the controls. OCN expression in reversible pulpitis was positively correlated to the expression of vascular endothelial growth factor, fibroblast growth factor, macrophage inflammatory protein-1ß, monocyte-derived chemokine, monocyte chemoattractant protein-1, interleukin (IL)-17, and soluble IL-2 receptor α and negatively correlated to that of IL-1α, IL-1ß, IL-8, granulocyte macrophage colony-stimulating factor, and macrophage inflammatory protein-1α. CONCLUSIONS: Profound understanding of the pulp inflammatory process would lead to new molecular treatment strategies. Our data indicate that OCN expression in reversible pulpitis is associated with angiogenic markers, suggesting its potential use in regenerative treatment.

Efficacy of polyphasic calcium phosphates as a direct pulp capping material.

OBJECTIVES: Polyphasic calcium phosphates (Poly-CaP), a complex of hydroxyapatite (HAp) and soluble calcium phosphates including alpha-tricalcium phosphate and tetracalcium phosphate, demonstrate promoting effects on hard tissue formation by osteoblasts. We hypothesized that a Poly-CaP block with a soluble calcium phosphates phase on one side and an insoluble HAp phase on the other side is useful for vital pulp therapy as it may promote dentin regeneration and provide the surface effective to achieve sealing. The purpose of this study was to investigate the efficacy of Poly-CaP as a direct pulp capping material by examining the Ca-release profile, the in vivo ability to induce reparative dentinogenesis, and the bonding of HAp surface with adhesive systems. METHODS: Poly-CaP prepared by annealing crude HAp disc was immersed in buffer solution at pH 7.4 or 4.0, and the concentration of Ca released was measured until 15 days. The pulp of 9-week-old Wister rat molar was exposed and capped with Poly-CaP or HAp block, and dentin bridge formation and pulpal inflammation was evaluated histopathologically after 2 or 4 weeks. Etch & rinse or self-etching adhesive was bonded to HAp surface, and the interface was observed using SEM. RESULTS: Poly-CaP exhibited continuous release of Ca with significantly greater amount than HAp at both pH conditions (P<0.05, Student's t-test). Animal tests demonstrated formation of complete dentin bridge at higher rate for Poly-CaP compared with HAp after 4 weeks (P<0.05, Steel-Dwass test). Impregnation of resin into etched HAp surface, with production of intimate contact at the bonding interface, was seen for all adhesives. CONCLUSIONS: Poly-CaP is a potentially useful material for direct pulp capping with the advantages to promote dentin bridge formation and to provide tight sealing by adhesives.