Management of compound odontoma with 70 denticles and impacted lateral incisor over an 8-year follow-up.

Odontomas are benign developmental tumors formed by the improper growth of completely differentiated epithelial and mesenchymal cells of odontogenic origin. The etiology of odontoma is unknown and it is detected during routine radiographic examination. The ideal management is early detection and surgical enucleation. The commonly associated clinical problems of odontomas are delayed exfoliation of primary teeth, delayed eruption or impaction of permanent teeth, displacement of teeth, root resorption, congenital missing, and widening of follicular space. Here, we describe a unique case of compound odontoma with a high number of denticles managed based on a definite decision support system over 8 years. An 8-year-old boy with 70 denticles in the left maxillary region underwent enucleation. On periodic follow-up, the associated impacted lateral incisor was extruded orthodontically.

Morphological and Histochemical Characterization of the Dermal Plates of Pleco (Hypostomus plecostomus).

Studying the dermal skeleton in fish is valuable for phylogenetic specification. The current study describes the detailed structure of the plecostomus dermal skeleton, including its morphogenesis and distribution in the skin. The denticles have a crown and a basal part and are embedded in bony depressions, to which they are attached by denticle ligaments. During denticle morphogenesis, denticle papillae formed from denticle precursor cells align in two cellular layers: an outer ameloblast precursor layer and an inner odontoblast precursor layer. The ameloblast precursors and odontoblast precursors differentiate and secrete enamel and dentine, respectively. We used different histochemical techniques, including Crossmon's trichrome staining, Weigert-Van Gieson staining, periodic acid-Schiff (PAS) staining, combined Alcian blue (AB; pH 2.5)/PAS staining, Weigert-Van Gieson staining, Mallory trichrome staining, and AB staining to distinguish the dentine and denticle ligaments. We used acridine orange to detect lysosome activity during denticle eruption. Transmission electron microscopy was used to detect the denticle ultrastructure, and scanning electron microscopy was used to detect the topographic distributions of different types of dermal tissues in different anatomical regions.

Acid-base adjustments and first evidence of denticle corrosion caused by ocean acidification conditions in a demersal shark species.

Global ocean acidification is expected to chronically lower the pH to 7.3 (>2200 µatm seawater pCO2) by the year 2300. Acute hypercapnia already occurs along the South African west and south coasts due to upwelling- and low-oxygen events, with increasing frequency. In the present project we investigated the impact of hypercapnia on the endemic demersal shark species Haploblepharus edwardsii. Specifically, we experimentally analysed acid-base regulation during acute and chronic hypercapnia, the effects of chronic hypercapnia on growth rates and on denticle structure- and composition. While H. edwardsii are physiologically well adapted to acute and chronic hypercapnia, we observed, for the first time, denticle corrosion as a result of chronic exposure. We conclude that denticle corrosion could increase denticle turnover and compromise hydrodynamics and skin protection.

Age-related morphological, histological and functional changes in teeth.

Throughout lifetime, the teeth are continuously exposed to numerous chemical and physical impacts, which cause the wear of the dental hard tissues, gingival recession and other oral changes with sometimes subsequent problems. Age-related wear of tooth surfaces reduces the dental enamel thickness and exposes deeper layers of enamel, which have different physical and chemical properties than the surface enamel. Gingival recession is the main causal factor of root caries and dentine hypersensitivity. Age-related changes in dentine include the formation of secondary dentine and the reduction in tubular lumen diameter (dentine sclerosis), which lead to a reduction in the volume of the pulp chamber. In addition to the reduction in the volume of pulp chamber, changes to the dental pulp also include dental pulp calcifications. The age-related physiological changes to the teeth should be carefully distinguished from pathological changes, especially when they induce pain or a negative impact on the oral health-related quality of life (OHRQoL) of the older individuals. Therefore, regular oral examinations coupled with early preventive measures should aim at maintaining oral health until old age.

Morphological Aspects of Oral Denticles in the Sharpnose Shark Rhizoprionodon lalandii (Müller and Henle, 1839) (Elasmobranchii, Carcharhinidae).

The oral denticles of some elasmobranchs are found on the surface of the oral cavity and are homologous to those on the body surface, being well developed, independent and non-growing, with varying morphology and distribution depending on the species. The structural and three-dimensional characteristics of oral denticles from the rostro-ventral surface of the sharpnose shark Rhizoprionodon lalandii were described following imaging by both light and scanning electron microscopy. The light microscopy results showed that the triangular shape of the denticles consisted of a base and an apex. Picrosirius staining showed the arrangement of collagen fibres and oral denticles, and a predominance of type-I collagen was found in both structures under polarized light. There was a broad homogeneous distribution of denticles on the ventral surface, forming a leaf-like shape with the cusp facing the caudal region. Interlocking, hexagonal, geometric structures on its rostral side and ridges on the rostral side of the oral denticles were observed under increased magnification. We concluded that the denticle morphology found in R. lalandii differ of others analysed species, and the descriptions of these structures therefore provide important information for the classification of the species. In this species, the main functions can be assigned to help reduce hydrodynamic drag, particularly by this being a species that uses ram ventilation, and to protect the epithelium of the oropharynx of abrasion and parasites.

Calcific metamorphosis with pathological root resorption in permanent teeth: morphohistometric evaluation of two cases / Metamorfosis calcificante asociada a reabsorción patológica radicular en dientes permanentes: evaluación morfohistométrica de dos casos

Calcific Metamorphosis (CM) is a pulpal response to dental trauma characterized by a deposition of hard tissue within the canal space. A tooth with CM usually presents a discoloration and a partial or total obliteration of the pulp canal space, and its vital pulp tests and symptoms are difficult. Since pulp necrosis cannot be supposed even the negative responses, the periradicular status is the only reliable criterion. Two permanent teeth diagnosed as CM and pathological root resorption, extracted from two males (22 and 53 years of age) due to severe mobility were prepared and sectioned for histological and histometrical evaluation. Images were captured, processed and measured in a total mapping of each specimen with software Pinnacle Studio 9.4® (Pinnacle Systems Inc.), Adobe® Photoshop® (CS 8.0.1, Adobe Systems Inc.) and Image J® (National Institute of Health, Bethesda, MD, USA). The images showed the simultaneous occurrence of CM and root resorption. The means of the total measurements showed that the area of radicular affection (R) was higher than the coronal affection (C), both in quantity (R: 13.75 mm2 -28.75%-/C: 4.7 mm2 -5.47%-) and quality (R: absence of CM / C: presence of CM). CM showed a fibrotic pattern, a cortical bone-like pattern and a cancellous bone-like pattern, representing a kind of reparative reaction probably initiated by the resorption process. Concurrent CM and pathological root resorption are uncommon in the same tooth, and the possibility to obtain specimens of permanent teeth to make histological and histometric evaluations of them represents a situation even more infrequent. This morphohistometric evaluation can expand the spectrum of useful variables to make clinical and therapeutic odontological decisions.

La Metamorfosis Calcificante (MC) es una respuesta pulpar a traumatismos dentales, caracterizada por un depósito de tejido duro dentro del canal pulpar. Un diente con MC usualmente presenta un cambio en el color y una obliteración parcial o total del espacio del canal pulpar, y sus respuestas a las pruebas de vitalidad y los mismos síntomas suelen ser de difícil diagnóstico. Dado que la necrosis pulpar no puede ser supuesta aún con respuestas negativas, el estado periradicular es el único criterio diagnóstico confiable. Dos dientes permanentes de dos pacientes masculinos (de 22 y 53 años) diagnosticados con MC asociada a reabsorción patológica de la raíz, extraídos por movilidad severa fueron preparados y seccionados para evaluación histológica e histométrica. Las imágenes fueron capturadas, procesadas y medidas en un mapeo total para cada espécimen utilizando software Pinnacle Studio 9.4® (Pinnacle Systems Inc.), Adobe® Photoshop® (CS 8.0.1, Adobe Systems Inc.) e Image J® (National Institute of Health, Bethesda, MD, USA). Las imágenes demostraron la concurrencia de MC y reabsorción radicular. Las medias de las mediciones totales expusieron que la superficie de afección radicular (R) fue mayor que la de afección coronaria (C), tanto en cantidad (R: 13,75 mm2 -28,75%-/C: 4,7 mm2 -5,47%-) como en calidad and (R: ausencia de MC / C: presencia de MC). La MC mostró patrones de fibrosis, de tejido similar a un hueso cortical y a un hueso esponjoso, representando una forma de reacción reparativa iniciada probablemente en el proceso de reabsorción. La concurrencia entre MC y reabsorción patológica radicular es rara en el mismo diente, y la posibilidad de obtener especímenes de dientes permanentes para evaluarlos histológica e histométricamente es aún menos frecuente. Esta evaluación histométrica permitiría expandir el espectro de variables útiles para la toma de decisiones clínicas y terapéuticas odontológicas.

Histological Evaluation of Allium sativum Oil as a New Medicament for Pulp Treatment of Permanent Teeth.

OBJECTIVE: The objective of this study was to evaluate the histo pathology effects of two medicaments Allium sativum oil and formocresol on the remaining pulp tissue of the permanent teething children. MATERIALS AND METHODS: A total of 18 premolars were included in this study. Two sound premolars were extracted and subjected to histological examination to show the normal pulp tissue. Pulpo tomy procedure was performed in the rest of the remaining 16 premolars; half of them using Allium sativum oil and the rest of the tested premolars were medicated using formocresol and all were sealed with suitable restoration. Then, premolars extracted at variable intervals (48 hours, 2 weeks, 1 month, 2 months), stained using hemotoxylin and eosin etain (H&E) and prepared for histopathology examination. RESULTS: Histological evaluation seemed far more promising for Allium sativum oil than formocresol. Histological evaluation revealed that teeth treated with Allium sativa oil showed infammatory changes that had been resolved in the end of the study. On the contrary, the severe chronic infammation of pulp tissue accompanied with formocresol eventually produced pulp necrosis with or without fibrosis. In addition, pulp calcification was evidenced in certain cases. CONCLUSION: Allium sativum oil is a biocompatible material that is compatible with vital human pulp tissue. It offers a good healing potential, leaving the remaining pulp tissue healthy and functioning.

Apical plug technique in a calcified immature tooth: a case report.

Traumatic injury to an immature tooth may result in pulpal necrosis secondary to pulp canal obliteration, which makes the management of the tooth a clinical challenge for dentists. The present case report describes an innovative apical plug technique with mineral trioxide aggregate in a calcified immature tooth using an ultrasonic tip and long, thin, tapered fissure burs. The technique was proven to be successful clinically and radiographically at 2 years postobturation.

Histologic evaluation of human pulp tissue after orthodontic intrusion.

INTRODUCTION: The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. METHODS: The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. RESULTS: The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. CONCLUSIONS: The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements.

Is hard tissue formation in the dental pulp after the death of the primary odontoblasts a regenerative or a reparative process?

OBJECTIVES: Conceptually, two types of tertiary dentine may be produced in response to caries and environmental irritations: "reactionary dentine" that is secreted by existing primary odontoblasts and "reparative dentine", formed after the death of the odontoblasts by proliferation and differentiation of progenitor cells into odontoblast-like cells. Because histologic evidence for tubular dentine generated by newly differentiated odontoblast-like cells is lacking in human teeth, the present study examined pulpal cellular changes associated with caries/restorations, in the presence or absence of pulpal exposures. METHODS: Ninety-six extracted human teeth were histologically processed and serial sectioned for light microscopy: 65 contained untreated enamel/dentine caries; 20 were heavily restored and 11 had carious exposures managed by direct pulp-capping. RESULTS: Sparsely distributed, irregularly arranged dentinal tubules were identified from the tertiary dentine formed in teeth with unexposed medium/deep caries and in restored teeth; those tubules were continuous with the tubules of secondary dentine; in some cases, tubules were absent. The palisade odontoblast layer was reduced to a single layer of flattened cells. In direct pulp-capping of pulp exposures, the defects were repaired by the deposition of an amorphous dystrophic calcified tissue that resembled pulp stones more than dentine, sometimes entrapping pulpal remnants. This atubular hard tissue was lined by fibroblasts and collagen fibrils. CONCLUSIONS: Histological evidence from the present study indicates that reparative dentinogenesis cannot be considered as a regenerative process since the so-formed hard tissue lacks tubular features characteristic of genuine dentine. Rather, this process represents a repair response that produces calcified scar tissues by pulpal fibroblasts. CLINICAL SIGNIFICANCE: Formation of hard tissue in the dental pulp after the death of the primary odontoblasts has often been regarded by clinicians as regeneration of dentine. If the objective of the clinical procedures involved is to induce healing, reduce dentine hypersensitivity, or minimise future bacteria exposure, such procedures may be regarded as clinical success. However, current clinical treatment procedures are not adept at regenerating physiological dentne because the tissues formed in the dental pulp are more likely the result of repair responses via the formation of calcified scar tissues.

The prevalence of pulp stones in historical populations from the middle Euphrates valley (Syria).

There are many reports in the literature concerning pulp stones in contemporary living populations, but there are no descriptions of cases of pulp stones and their prevalence in populations of the past. Here we present a study of pulp stones in a series of archaeologically derived samples from the Middle Euphrates Valley (Syria) obtained from two sites: Terqa and Tell Masaikh. The specimens were assigned to five periods: Early Bronze (2650-2350 BC); Middle Bronze (2200-1700 BC); late Roman (AD 200-400); Islamic (AD 600-1200); and Modern Islamic (AD 1850-1950). A total of 529 teeth representing 117 adult individuals of both sexes were examined. Pulp stones were identified by X-ray and 10 selected specimens were sectioned for histological study. Pulp stones were found in 99 of 117 individuals (85%) and in 271 of 529 (51%) teeth. Pulp stone prevalence was found to increase with age, for individuals of older age classes have more pulp stones than younger individuals. Intriguingly, the prevalence of single pulp stones was higher among older individuals (36-45, >46), while younger individuals (17-25, 26-35) more often possessed multiple stones. Individuals with moderate to highly advanced dental wear have pulp stones significantly more often than individuals whose tooth wear is limited to invisible or very small facets. Though there is no statistical significance in the prevalence of pulp stones across chronological periods, it appears that a high level of calcium in the diet is accompanied by a greater prevalence of pulp stones.

Pulp stones can help in detection of calculus in the kidneys and/or in the bile--fact or fiction?

BACKGROUND: Pulp stones or denticles are frequently found in the dental pulp; there is, however, scarce evidence about this phenomenon. Regardless of the obvious endodontic problem of inhibiting access to the canals and their further treatment, they have not been given great importance. The latest experiences of scientific and practical research, including examinations of dental calcifications and their association with calcifications/calculi in the organism, have not been included in the literature. AIM: To investigate the possible association between dental calcifications and calculi in the kidney and/or bile. METHODS: The study group included 200 patients diagnosed with pulptits chronica. All patients underwent dental and systematic examinations. Dental examination included x-rays, which detected the presence of calcifications in the dental pulps. Histopathological analysis of extirpated pulps was also made. Clinical examination comprised ultrasound that detected calculi. RESULTS: The results of the histopathological analysis of the extirpated pulps from the group of patients without denticles, but with calculi in their kidneys, bile and/or other organs, showed a regular presence of "sand" in large quantities in dental pulps. The presence of "sand" was depicted as presence of dystrophic calcifications. There was a percentage difference between the two groups: calculi in the organism (kidney and bile) and denticles--70% and calculi in the organism without denticles--30%. The Student's t-test showed a statistically significant difference for P=0.0000. This study defines the association between the calculi in the organism and the presence of dental calcifications, as well as their possible bacterial association.

Are referred inaccessible human primary molar teeth really inaccessible?

Despite a body of compelling evidence pertaining to the root canal accessibility of primary teeth, the number of referrals for inaccessibility of primary molars is considerable. The aim of the present study was to evaluate the prevalence of true and false primary molar inaccessibility among subjects who had been referred by general and pediatric dentists. We examined 199 primary molars in 156 patients (87 males, 69 females) aged 3-7 years who were referred by 215 general and 35 pediatric dentists. Problems related to inaccessibility were recorded for each tooth and any individual canal. One hundred seventy-five inaccessible teeth (87.9%) were successfully rehabilitated to accessible status (P < 0.001). The most frequent cause of inaccessibility was an inappropriate access cavity (42.3%), followed by difficult canals (32.6%) and orifice calcification (25.2%). The tooth most frequently reported as inaccessible was the maxillary first molar (40.2%), and that least frequently reported was the mandibular second molar (11.6%). The distobuccal canal of the maxillary first molar and the mesiolingual canal of the mandibular first molar were the most commonly inaccessible canals (P < 0.001). Only 1 out of 8 teeth referred as inaccessible was truly inaccessible. It seems that root canal inaccessibility is mostly attributable to lack of expertise among individual practitioners.

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.

Advanced glycation end-products enhance calcification in cultured rat dental pulp cells.

INTRODUCTION: Amorphous calcification frequently appears in dental pulp tissues of diabetic patients; however, its pathologic process has not been fully elucidated. We previously found that pulp stones and thickened predentin occurred more frequently in diabetic rats. Recent findings demonstrated that accumulation of advanced glycation end-products (AGE) might be involved in vascular calcification complicated with diabetes. The aim of this study was to determine the effect of AGE on calcified nodule formation by rat dental pulp cells in culture. METHODS: Rat dental pulp cells and gingival fibroblasts were independently cultured with 50 and 100 µg/mL AGE. Alkaline phosphatase activity and calcified nodule formation were measured. Expressions of receptor for AGE, osteopontin (OPN), and osteocalcin (OCN) mRNA were determined by quantitative real-time polymerase chain reaction. Protein levels of OPN and OCN secreted in culture medium were quantified by enzyme-linked immunosorbent assay. RESULTS: AGE (50 and 100 µg/mL) markedly increased both alkaline phosphatase activity and calcified nodule formation in dental pulp cells (P < .01), whereas it did not affect those in gingival fibroblasts. Real-time polymerase chain reaction analysis revealed that AGE increased mRNA expressions of receptor for AGE, OPN, and OCN in dental pulp cells (P < .05). Enzyme-linked immunosorbent assay analysis revealed that the protein levels of OPN and OCN produced by dental pulp cells were higher in AGE-treated than in untreated cells (P < .05). CONCLUSIONS: AGE enhanced the calcification potentials of rat dental pulp cells, suggesting that it may stimulate pathologic calcification of diabetic dental pulp tissues.

Histological and immunohistochemical analyses of the chronology of healing process after immediate tooth replantation in incisor rat teeth.

Dental tissues have special characteristics, and its regenerative capacity is noteworthy. However, understanding the circumstances that lead to regeneration is challenging. In this study, the chronology of the healing process after immediate replantation of rat incisor teeth was examined by histological and immunohistochemical analyses within a 60-day period. Thirty-six male Wistar rats had their maxillary right incisors extracted and replanted after 15 min in saline storage. The rats were sacrificed immediately 3, 7, 15, 28, and 60 days after replantation. The histological analysis showed rupture of the periodontal ligament and formation of a blood clot, which started being replaced by a connective tissue after 3 days. At 7 days, the gingival mucosa epithelium was reinserted and areas of root resorption could be seen. At 15 days, the periodontal ligament was repaired. At 3 days, the pulp presented an absence of the odontoblast layer, which started being replaced by a connective tissue. This tissue suffered gradual calcification, filling the root canal at 28 and 60 days. The root ends were closed. The immunohistochemical analysis revealed greater expression of OP, OPG, and RANK proteins in the initial periods (0 and 3 days), while TRAP expression predominated at 28 and 60 days (P < 0.05). In conclusion, in delayed tooth replantation, there is great new bone formation activity in the earlier periods of the repair process, while a predominance of bone resorption and remodeling is observed in the more advanced periods.