[The importance of pulp therapy in deciduous teeth]. / Importance des traitements pulpaires en denture de lait.

Preserving primary teeth is crucial for maintaining the maxillary growth, aesthetics, mastication, and speech and for preventing from abnormal habits. Given the peculiar anatomy of the primary tooth, caries grow faster and more frequently to the pulp. In pediatric dentistry, new methods and enhanced material have been recently released on the market and broadened the field of treatments. In this paper, we review the pulp diseases affecting children and focus on the current root canal therapies that favour the physiological primary tooth loss.

Conserver les dents de lait est essentiel pour assurer la croissance des maxillaires, l'esthétique, la mastication et la phonation ainsi que pour prévenir l'apparition de dysfonctions. Vu les particularités anatomiques des dents de lait, la carie progresse toujours plus rapidement et plus fréquemment jusqu'à la pulpe. L'avènement de nouvelles techniques et de nouveaux matériaux en dentisterie pédiatrique a élargi nos possibilités thérapeutiques. De même, l'interdiction d'utilisation de certains produits a conduit le pédodontiste à devoir trouver des alternatives de traitement. Le but de cet article est de faire le point sur les pathologies pulpaires chez l'enfant et sur les thérapeutiques endocanalaires actuelles.

Estimates of sensitivity and specificity of electric pulp testing depend on pulp disease spectrum: a modelling study.

AIM: To demonstrate how the spectrum of diseased pulps may influence sensitivity and specificity in diagnostic studies on pulp status. METHODOLOGY: An original sample from a previous study consisting of 59 teeth scheduled for root canal treatment was used where the relationship between the response to electric pulp testing and the visual status of the pulp was evaluated. To alter the spectrum of diseased pulps, a hypothetical sample of asymptomatic teeth with deep caries lesions was added to the original sample. Sensitivity and specificity were then compared for the two samples. RESULTS: In the original sample of 59 teeth, sensitivity was 72% and specificity 90%. When the spectrum of diseased pulps was altered, sensitivity decreased to 67% and specificity increased to 97%. The change in disease spectrum also decreased the prevalence of necrotic pulps. CONCLUSIONS: The spectrum of diseased pulps included in a diagnostic study on the accuracy of electric pulp testing, and indirectly also disease prevalence (here pulp necrosis), influences estimates of sensitivity and specificity. This implies that estimates of diagnostic accuracy from one study with a particular tooth population spectrum may not apply to another tooth population with a different disease spectrum.

[An index for untreated severe caries]. / Een index voor onbehandelde ernstige cariës.

Hardly any data are available on the clinical consequences of untreated severe caries, because there is no method to quantify the prevalence of oral conditions resulting from untreated caries. In the Philippines, an index was developed which records for (the location of) each tooth whether caries has reached the dental pulp, whether ulceration is present in the surrounding soft tissues due to sharp edges of fragments of a tooth lost due to caries, or whether a fistula or abscess is present. By adding the index to the existing Decayed Missing Filled Tooth index, insight is provided on the extent and the consequences of untreated caries and research may be carried out on its possible impact on the general health and wellbeing of national populations.

Diagnosis and Management of Apical Fenestrations Associated with Endodontic Diseases: A Literature Review.

Apical fenestration describes a window-like opening of the alveolar bone that involves the root apex of the associated tooth. Mucosal fenestration is a similar defect of the overlying mucosa and, when presented with a concomitant apical fenestration, may expose the root apex to the oral environment. A fenestration may arise from physiological and pathological processes. Although its presence does not necessitate treatment per se, these lesions have significant clinical implications when associated with endodontic diseases. Apical fenestrations associated with endodontic infections are relatively uncommon and can easily be overlooked or misdiagnosed. A thorough understanding of these lesions is key for timely diagnosis and successful management. The aim of this study was to review the epidemiology, aetiological factors, characteristics, management methods and potential outcomes of apical fenestrations associated with endodontic diseases. A search of online databases for relevant studies was conducted. With the inclusion of hand searched articles, 20 articles, consisting of case reports and series, were identified, and the key characteristics of each case were summarised. Apical fenestrations were found to be most commonly associated with maxillary teeth and almost always occur on the buccal aspect of the alveolar bone. Clinicians may consider the possibility of an apical fenestration with concurrent endodontic pathology when patients present with non-healing sinus tracts, exposed tooth apices and/or persistent pain after endodontic treatment, particularly on palpation and mastication. Clinical signs and symptoms can vary, hence cone-beam computed tomography is an important tool for diagnosis. The management involves surgically restoring a favourable anatomical configuration of the root apex in relation to the alveolar bony housing and may be combined with guided tissue regeneration and/or grafting procedures. Sloughing, reopening and infection are potential complications. The literature on apical fenestrations associated with endodontic diseases is limited, thus further research is needed to develop evidence-based guidelines for the diagnosis and management of these lesions.

Preoperative predictors of number of root canals clinically detected in maxillary molars: a PennEndo Database study.

The purpose of this investigation was to evaluate the concomitant influence of several variables on the number of root canals clinically detected in maxillary molars. The study used multiple logistic regression analysis on data from 1328 patients, aged 6-82 years, who received nonsurgical root canal treatment on maxillary molars at the University of Pennsylvania from 2000-2006. The number of canals was used as the dependent variable, whereas tooth type, age, caries, referral source, restoration, and pulpal and periapical diagnosis were used as independent variables. One was 0.98 times less likely to detect more canals when the age increased by 1 year. Similarly, one was 1.4 times more likely to detect canals in teeth with caries than teeth without caries. When these independent variables were controlled, only age of the individual was significantly related to number of root canals detected.

Immunohistochemical localization of LIM mineralization protein 1 in pulp-dentin complex of human teeth with normal and pathologic conditions.

LIM mineralization protein 1 (LMP-1) is an essential positive regulator of osteoblast differentiation and maturation and bone formation. However, the expression and distribution of LMP-1 in human teeth are largely unknown. The aim of this study was to detect the expression of LMP-1 in normal healthy human teeth and human teeth with various pathologic conditions. LMP-1 expression was determined by immunohistochemistry in all of the samples including 12 healthy teeth, 10 teeth with caries, 12 teeth with pulpitis, and 4 teeth with pulp calcification. We found that LMP-1 was expressed primarily in predentin, odontoblasts, and endothelial cells of the blood vessels of healthy teeth. In addition, LMP-1 expression was also found in unmineralized reparative dentin, odontoblast-like cells, and pulp fibroblasts in teeth with caries and pulpitis. Furthermore, we found LMP-1 expression on the surface of the pulp stone or in the residual predentin of teeth with pulp calcification. Our data suggest that LMP-1 plays a role in odontoblast differentiation and dentin matrix mineralization of human teeth with normal and pathologic conditions.

Pathological studies of cheek teeth apical infections in the horse: 5. Aetiopathological findings in 57 apically infected maxillary cheek teeth and histological and ultrastructural findings.

Examination of 57 apically infected maxillary cheek teeth (CT) showed one or more viable pulps and minimal apical calcified tissue changes present in recently infected CT. With chronic infections, pulps were necrotic or absent, pulp horns were filled with food if occlusal pulpar exposure was present, and gross caries of dentine was occasionally present. With chronic infections, the apical changes varied from gross destructive changes in some teeth, to extensive proliferative calcified apical changes in others. Infundibular caries was believed to cause apical infection in just 16% of infected (maxillary) CT, anachoretic infection in 51%, periodontal spread in 12%, fractures and fissures in 9%, dysplasia in 5% and miscellaneous or undiagnosed causes in 7%. Histology showed viable pulp and absence of circumpulpar dentinal changes in some recently infected CT, but chronically infected teeth had loss of predentine and progressive destruction of the circumpulpar secondary, and even primary dentine, with bacteria identified within the dentinal tubules surrounding infected pulps. Tertiary dentine deposition was rarely detected. Scanning and transmission electron microscopy confirmed these histological findings and showed extensive destructive changes, especially to the dentinal architecture surrounding the pulp chambers of some infected teeth.

Etiologic role of root canal infection in apical periodontitis and its relationship with clinical symptomatology.

Evidence shows the polymicrobial etiology of endodontic infections, in which bacteria and their products are the main agents for the development, progression, and dissemination of apical periodontitis. Microbial factors in necrotic root canals (e.g., endotoxin) may spread into apical tissue, evoking and supporting a chronic inflammatory load. Thus, apical periodontitis is the result of the complex interplay between microbial factors and host defense against invasion of periradicular tissues. This review of the literature aims to discuss the complex network between endodontic infectious content and host immune response in apical periodontitis. A better understanding of the relationship of microbial factors with clinical symptomatology is important to establish appropriate therapeutic procedures for a more predictable outcome of endodontic treatment.

Pulp canal obliteration after traumatic injuries in permanent teeth - scientific fact or fiction?

Pulp canal obliteration (PCO) is a frequent finding associated with pulpal revascularization after luxation injuries of young permanent teeth. The underlying mechanisms of PCO are still unclear, and no experimental scientific evidence is available, except the results of a single histopathological study. The lack of sound knowledge concerning this process gives rise to controversies, including the most suitable denomination. More than a mere semantic question, the denomination is an important issue, because it reflects the nature of this process, and directly impacts the treatment plan decision. The hypothesis that accelerated dentin deposition is related to the loss of neural control over odontoblastic secretory activity is well accepted, but demands further supportive studies. PCO is seen radiographically as a rapid narrowing of pulp canal space, whereas common clinical features are yellow crown discoloration and a lower or non-response to sensibility tests. Late development of pulp necrosis and periapical disease are rare complications after PCO, rendering prophylactic endodontic intervention useless. Indeed, yellowish or gray crown discoloration may pose a challenge to clinicians, and may demand endodontic intervention to help restore aesthetics. This literature review was conducted to discuss currently available information concerning PCO after traumatic dental injuries (TDI), and was gathered according to three topics: I) physiopathology of PCO after TDI; II) frequency and predictors of pulpal healing induced by PCO; and III) clinical findings related to PCO. Review articles, original studies and case reports were included aiming to support clinical decisions during the follow-up of teeth with PCO, and highlight future research strategies.

Association of S100 calcium-binding protein A12, receptor for advanced glycation endproducts, and nuclear factor-κB expression with inflammation in pulp tissues from tooth caries.

AIM: S100 calcium-binding protein A1 (S100A12) is a pro-inflammatory molecule which is secreted during inflammation and induces chemotaxis and the production of pro-inflammatory cytokines via interaction with receptor for advanced glycation endproducts (RAGE) and subsequent, activation of nuclear factor-κB (NF-κB). The present study was designed to determine the expression levels of S100A12, RAGE, and NF-κB in the inflamed pulp of carried teeth. METHODS: In the present study, mRNA from 50 inflamed pulp and 50 healthy pulp were used for expression studies using real-time polymerase chain reaction. The expression levels of S100A12, RAGE, and NF-κB were compared between inflamed and healthy tissues. RESULTS: The results revealed that the expression of S100A12, but not of RAGE or NF-κB, was significantly decreased in inflamed pulp when compared to healthy pulp. mRNA levels of RAGE were also increased in the inflamed pulp taken from men when compared with women. CONCLUSION: The results suggest that S100A12 does not participate in the induction of inflammation in dental pulp. However, RAGE can participate in the inflammation in the pulp of males.

Pulpal status of hypomineralized permanent molars.

PURPOSE: Young patients with hypomineralized teeth frequently complain of symptoms suggestive of dentin hypersensitivity. It has been proposed that these symptoms may be exacerbated by an underlying pulpal inflammation. The purpose of the study was to determine the pulpal status of hypomineralized teeth. METHODS: The experimental material comprised 25 sound and 19 hypomineralized permanent first molars obtained from children requiring dental extractions under general anesthesia. Pulp sections were processed for indirect immunofluorescence using combinations of: (1) protein gene product 9.5; (2) leukocyte common antigen; and (3) Ulex europaeus I lectin. Image analysis was then used to determine the percentage area of staining of each label. RESULTS: Innervation density was significantly greater in the pulp horn and subodontoblastic region of hypomineralized teeth than in sound teeth. Immune cells were most abundant within pulps of hypomineralized teeth exhibiting enamel loss. Vascularity was found to be similar for both hypomineralized and sound teeth, but was significantly greater in hypersensitive hypomineralized samples. CONCLUSION: This study provides biological evidence that inflammatory changes may be present within the pulpal tissue of these teeth.

Axin2-expressing cells differentiate into reparative odontoblasts via autocrine Wnt/ß-catenin signaling in response to tooth damage.

In non-growing teeth, such as mouse and human molars, primary odontoblasts are long-lived post-mitotic cells that secrete dentine throughout the life of the tooth. New odontoblast-like cells are only produced in response to a damage or trauma. Little is known about the molecular events that initiate mesenchymal stem cells to proliferate and differentiate into odontoblast-like cells in response to dentine damage. The reparative and regenerative capacity of multiple mammalian tissues depends on the activation of Wnt/ß-catenin signaling pathway. In this study, we investigated the molecular role of Wnt/ß-catenin signaling pathway in reparative dentinogenesis using an in vivo mouse tooth damage model. We found that Axin2 is rapidly upregulated in response to tooth damage and that these Axin2-expressing cells differentiate into new odontoblast-like cells that secrete reparative dentine. In addition, the Axin2-expressing cells produce a source of Wnt that acts in an autocrine manner to modulate reparative dentinogenesis.

Pulp and apical tissue response to deep caries in immature teeth: A histologic and histobacteriologic study.

Descriptions of the pathologic changes in the pulp and associated apical structures of human immature teeth in response to deep caries are lacking in the literature. OBJECTIVES: This article describes the histologic events associated with the radicular pulp and the apical tissues of human immature teeth following pulp inflammation and necrosis. METHODS: Twelve immature teeth with destructive caries lesions were obtained from 8 patients. Two intact immature teeth served as controls. Teeth were extracted for reasons not related to this study and immediately processed for histopathologic and histobacteriologic analyses. Serial sections were examined for the pulp conditions and classified as reversible or irreversible pulp inflammation, or pulp necrosis. Other histologic parameters were also evaluated. RESULTS: In the 3 cases with reversible pulp inflammation, tissue in the pulp chamber showed mild to moderate inflammation and tertiary dentin formation related to tubules involved in the caries process. Overall, the radicular pulp tissue, apical papilla and Hertwig's epithelial root sheath (HERS) exhibited characteristics of normality. In the 3 cases with irreversible pulp inflammation, the pulps were exposed and severe inflammation occurred in the pulp chamber, with minor areas of necrosis and infection. Large areas of the canal walls were free from odontoblasts and lined by an atubular mineralized tissue. The apical papilla showed extremely reduced cellularity or lack of cells and HERS was discontinuous or absent. In the 6 cases with pulp necrosis, the coronal and radicular pulp tissue was necrotic and colonized by bacterial biofilms. The apical papilla could not be discerned, except for one case. HERS was absent in the necrotic cases. CONCLUSION: While immature teeth with reversible pulpitis showed histologic features almost similar to normal teeth in the canal and in the apical region, those with irreversible pulpitis and necrosis exhibited significant alterations not only in the radicular pulp but also in the apical tissues, including the apical papilla and HERS. CLINICAL SIGNIFICANCE: Alterations in the radicular pulp and apical tissues help explain the outcome of current regenerative/reparative therapies and should be taken into account when devising more predictable therapeutic protocols for teeth with incomplete root formation.

Relationship of patient complaints and signs to histopathologic diagnosis of pulpal condition.

The correlation between the histopathologic examination of pulp biopsy specimens and patients' complaints and signs was investigated. The sensitivity, specificity and reliability of each complaint and sign, and the characteristics of pain that are associated with treatable and untreatable pulp states is proposed. Pulp specimens were obtained from teeth that required endodontic treatment. Clinical data were recorded to identify each patient's complaints. The pulp specimens were processed and the histopathologic diagnoses were categorised and correlated with the patients' complaints. Of the 240 cases, 100 (41.7%) were diagnosed as atrophic pulp or pulposis; 4 (1.7%) as acute pulpitis; 64 (26.7%) as transitional stage; 56 (23.3%) as chronic pulpitis, and 16 (6.7%) as acute pulpitis superimposed on a chronic pulpitis. Results showed that previous pain (p < 0.05), spontaneous pain (p < 0.01), and prolonged pain on cold stimuli (p < 0.05), were significantly more frequent in the patients with chronic pulpitis compared to those with pulposis or transitional stage. We concluded that clinicians must consider the sensitivity and specificity of patient complaints and signs in order to perform a diagnosis based upon clinical evidence.

[Endodontic diagnosis]. / Endodontische diagnostiek.

In this article endodontic diagnosis is discussed following the clinical diagnostic process. A description is given about pain from endodontic origin and a comprehensive overview of the clinical diagnostic tests is discussed. In the chapter clinical classification of pulpal and periapical disorders all the possible endodontic diagnoses are extensively discussed.

The expression of hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and HCN2 in the rat trigeminal ganglion, sensory root, and dental pulp.

Hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and 2 (HCN2) are abundantly expressed in primary sensory neurons and contribute to neuronal excitability and pathological pain. We studied the expression of HCN1 and HCN2 in the rat trigeminal ganglion (TG) neurons and axons in the dental pulp, and the changes in their expression following inflammation, using light- and electron-microscopic immunocytochemistry and quantitative analysis. HCN1 and HCN2 were expressed predominantly in large-sized, neurofilament 200-immunopositive (+) or parvalbumin+ soma in the TG whereas they were expressed mostly in unmyelinated and small myelinated axons in the sensory root. The expression was particularly strong along the plasma membrane in the soma. In the dental pulp, majority of HCN1+ and HCN2+ axons coexpressed calcitonin gene-related peptide. They were expressed mainly in the peripheral pulp and pulp horn where the axons branch extensively in the dental pulp. The expression of HCN1 and HCN2 in TG neurons increased significantly in rats with experimentally induced inflammation of the dental pulp. Our findings support the notion that HCN1 and HCN2 are expressed mainly by both the soma of mechanosensitive neurons in the TG and peripheral axons of nociceptive neurons in the sensory root, and may play a role in the mechanisms of inflammatory pain from the dental pulp.

A prognostic model for assessment of the outcome of endodontic treatment: Effect of biologic and diagnostic variables.

OBJECTIVE: Many biological variables, endodontic treatment factors, and restorative considerations have been suggested in the literature to affect the outcome of endodontic treatment. However, few attempts have been made recently to study these variables further. The purpose of this study was to identify the biologic and endodontic treatment-associated variables that are most predictive of treatment outcome for conventional endodontic therapy and to determine the magnitude of risk these variables pose on the outcome. STUDY DESIGN: The population of this historical prospective cohort study comprised a total of 200 teeth with 441 root canals. Diagnostic and treatment information was abstracted from the original patient records. An endodontic follow-up examination was conducted 4 +/- 0.5 years after obturation. Each tooth/root was analyzed according to 3 indices of periradicular status at 2 time points. The main outcome measure was the presence of apical periodontitis. The criteria used for evaluation of the outcome were modified from Strindberg. Data were subjected to univariate and multivariate analysis. Logistic regression models were fit by using various clinical measures to determine which combination of biologic and treatment-associated factors best predicted treatment outcome. RESULTS: The preoperative pulp diagnosis, the periapical diagnosis, the preoperative periapical radiolucency size, and the sex of the patients were revealed, by means of univariate analysis, to exert a significant influence on endodontic treatment outcome (P <.05). In the logistic regression model, the strongest effect on postoperative healing was the presence and magnitude of preoperative apical periodontitis. In the presence of this variable, no other factor contributed value to the prediction. The correct prediction of this model was 74.7% (P <.05). CONCLUSION: The major biologic factors influencing the outcome of endodontic treatment appear to be the extent of microbiological insult to the pulp and periapical tissue, as reflected by the periapical diagnosis and the magnitude of periapical pathosis.

Comparison of clinical and histologic diagnoses in periapical lesions.

OBJECTIVE: To determine the frequency with which histopathologic examination of periapical biopsy specimens contributed information not anticipated clinically. STUDY DESIGN: Clinical and histopathologic information from 805 sequentially submitted periapical biopsy specimens over a 2-year period was compared. Clinical data included endodontic status, age and sex of patient, location of lesion, and submitting clinician. Histopathologic diagnoses were categorized as 1) sequelae of pulpal necrosis (SPN), 2) complicated SPN (CSPN) with infection or antral involvement, or 3) periapical lesions unrelated to pulpal necrosis (PLUPN). RESULTS: Of the 805 cases, 788 (97.9%) were SPN, 9 (1.1%) were CSPN, and 8 (1%) were PLUPN, representing a range of locally aggressive but benign lesions and 1 malignancy. Comparison of clinical and histologic diagnoses indicated that the clinical interpretation was inaccurate in 4.1% of cases (suggesting SPN in PLUPN cases or PLUPN in SPN cases). In another 0.9% of cases, the histologic analysis (indicating CSPN) contributed additional information to the clinical diagnosis. CONCLUSIONS: A histopathologic examination contributed clinically relevant information in 5.0% of submitted cases. General extrapolation of this figure is not possible. Theoretical considerations, which could positively or negatively bias this figure, are discussed.

[Establishment of dental pulp hyperemia in an animal experiment model].

To establish an animal model of dental pulp hyperemia, 96 molars in 12 Wistar rats were studied. In each rat, the four right molars, including the right upper and lower first and second molars, were assigned as the experimental group. The four left corresponding molars in each rat were included in the control group. The animals were anesthetized and a 3% silver nitrate solution was applied to the exposed dentin at the cusp tip of the molars for one minute. After 2, 5, and 24 hours, four animals in each subgroup were sacrificed. The upper and lower jaws in conjunction with the dentition were removed and fixed in a 10% neutral formalin solution for 24 hours. The first and second molars and the surrounding alveolar bone in en bloc were trimmed off, fixed for another 24 hours, and processed according to routine histological procedures. The histopathologic changes in the dental pulp were examined by light microscopy. For convenience of interpretation, the intensity of the pulp tissue reaction was graded as follows: grade O: normal pulp tissue; grade I: vessel dilatation and congestion, as well as stromal edema; grade II: focal pulp hemorhage and plasma extravasation; grade III: pulp tissue destruction including pyknotic change in the odontoblastic nuclei; and grade IV: abscess formation in the pulp tissue.(ABSTRACT TRUNCATED AT 250 WORDS)