Pulp Horn Research Articles

Presentation of age-related changes of the pulp horns in equine upper cheek teeth by MRI

Presentation of age-related changes of the pulp horns in equine upper cheek teeth by MRI

Immediate and delayed micro-tensile bond strength of different luting resin cements to different regional dentin

We sought to evaluate immediate and delayed micro-tensile bond strength of Panavia F2.0 and Multilink Sprint resin cement to superficial, deep and cervical dentin. Thirty-six freshly extracted non-carious human molars were sectioned in the mesiodistal direction to expose three different dentin regions including superficial dentin (1 mm below the dentine-enamel junction), deep dentin (1 mm above the highest pulp horn) and cervical dentin (0.5 mm above the cemento-enamel junction and 0.5 mm below the dentine-enamel junction). Resin cements were applied on dentin surfaces and composite blocks were luted under constant seating pressure. Each group was divided into three subgroups according to time intervals. Specimens were sectioned to obtain sticks of 1 mm2 in diameter and subjected to microtensile bond strength testing at a cross head speed of 1 mm/min. Both resin cements showed higher micro-tensile bond strength to superficial dentin than that to deep or cervical dentin (P < 0.001). Micro-tensile bond strengths of Panavia F2.0 were higher than those of Multilink Sprint at different dentin regions (P < 0.001). Immediate micro-tensile bond strengths were higher than those of delayed micro-tensile bond strengths for both resin cements (P < 0.001). It was concluded that resin cements with different chemical formulations and applications yield significantly different micro-tensile bond strengths to different dentin regions.

Clinical & Histologie Study of Human Pulpal Response to Calcium Hydroxide, Resorcinol & Zinc Oxide Eugenol as a Direct Pulp Capping Agent

The healthy pulp has the inherent potential for healing provided the exposure site is kept bacteria free. Various materials have been tried as direct pulp capping (DPC) agents. In this study, calcium hydroxide, Resorcinol (Resinifiying Agent) and zinc oxide eugenol were used as DPC agents. Under aseptic conditions, Class I cavity was prepared on premolar teeth and small exposure was made at pulp horn and experimental materials were placed over the exposure site and remaining cavity filled with quick setting zinc oxide eugenol cement. After treatment, the teeth were extracted and processed for routine histologie evaluation. Teeth with calcium hydroxide show resolution of inflammatory response and reparative dentin formation after 90 days. Teeth with resorcinol showed increase fibrosis and widened predentin layer whereas zinc oxide eugenol shows only chronic inflammation and no evidence of reparative dentin formation. By evaluating clinical and histological response with these materials, calcium hydroxide and resorcinol can be used as a direct pulp capping agent but long terni study required

Regional odontodysplasia: Orthodontic treatment and transplantation of premolars

Regional odontodysplasia is a rare and unique dental anomaly involving both dentitions, but mostly the teeth of 1 quadrant. This report describes the combined surgical and orthodontic treatment of a boy with regional odontodysplasia. The mandibular right central and lateral incisors and the canine (as well as the deciduous predecessors) were affected. In a 2-step procedure, the maxillary right and left second premolars were autotransplanted to the affected area. The extraction sites in the maxilla were closed, and a good functional occlusion was established.

Pulpar temperature changes during mechanical reduction of equine cheek teeth: Comparison of different motorised dental instruments, duration of treatments and use of water cooling

Although equine motorised dental instruments are widely used, there is limited information on their thermal effect on teeth. The recently described variation in subocclusal secondary dentine depth overlying individual pulp horns may affect heat transmission to the underlying pulps. This study compared the effect of 3 different equine motorised dental instruments on the pulpar temperature of equine cheek teeth with and without the use of water cooling. It also evaluated the effect of subocclusal secondary dentine thickness on pulpar temperature changes. A thermocouple probe was inserted into the pulp horns of 188 transversely sectioned maxillary cheek teeth with its tip lying subocclusally. Pulpar temperature changes were recorded during and following the continuous use of 3 different equine motorised dental instruments (A, B and C) for sequential time periods, with and without the use of water cooling. Using motorised dental instrument B compared with either A or C increased the likelihood that the critical temperature was reached in pulps by 8.6 times. Compared with rasping for 30 s, rasping for 45, 60 and 90 s increased the likelihood that the critical temperature would be reached in pulps by 7.3, 8.9 and 24.7 times, respectively. Thicker subocclusal secondary dentine (odds ratio [OR] = 0.75/mm) and water cooling (OR = 0.14) were both protective against the likelihood of the pulp reaching the critical temperature. Prolonged rasping with motorised dental instruments increased the likelihood that a pulp would be heated above the critical temperature. Increased dentinal thickness and water cooling had protective roles in reducing pulpar heating. Motorised dental instruments have the potential to seriously damage equine pulp if used inappropriately. Higher speed motorised dental instruments should be used for less time and teeth should be water cooled during or immediately after instrument use to reduce the risk of thermal pulpar damage.

The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

BackgroundRecent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages.ResultsMaxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05). In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most commonly seen in teeth ≤5 years. A segmented pulp system was found in 72% of the investigated teeth. Segmentation into separate mesial and distal pulp compartments was most commonly present. Pulp horn 4 coalesced either with the mesial pulp horns 1 and 3 or with the distal pulp horns 2 and 5.ConclusionsDetails of the pulpar anatomy of equine cheek teeth are provided, supporting the continuous advancement in endodontic therapy. Numerous individual configurations of the pulp system were obtained in maxillary cheek teeth, but much less variability was seen in mandibular cheek teeth.

Micro-tensile bond strength of adhesives to pulp chamber dentin after irrigation with Ethylenediaminetetraacetic acid

Aim:The aim of this study was to evaluate the influence of different concentrations of Ethylenediaminetetraacetic acid (EDTA) solution on adhesion, that is, the bond strength of the different adhesive systems, to the pulp chamber dentin.Materials and Methods:Recently extracted, sound, human, third molars were cut horizontally to expose the pulp horn. The roof of the pulp chamber and pulp tissue was removed. The teeth were then divided into five main groups. The teeth in each group were treated as follows: group 1, irrigated with saline; group 2, with 5% EDTA for 5 minutes; group 3, with 15% EDTA for 5 minutes; group 4, with 17% EDTA for 5 minutes and group 5, with 19% EDTA for 5 minutes. Treated specimens were dried and divided into 2 subgroups for adhesives; bonded with a total-etching adhesive (Adper Scotchbond Multi-purpose - ASB) or a one bottle of self-etch adhesive system (Clearfil S3 Bond – CS3). After the bonding procedure and composite restoration, teeth were sectioned and dentin sticks were obtained from each group for micro tensile testing (n = 10). Micro tensile testing was performed and scanning electron microscope (SEM) photographs were taken for each irrigated group.Results:In the ASB group, saline showed statistically higher bond strength values at the different concentrations of EDTA, while the micro-tensile bond strengths of the different concentrations of EDTA were not statistically different. In the CS3 group, saline and 5% EDTA showed statistically higher bond strength values than 17% and 19% EDTA, while the micro-tensile bond strengths of 15% EDTA compared to saline and 5% EDTA and 15% EDTA compared to 17% EDTA and 19% EDTA, were not statistically different.Conclusion:This study showed that EDTA irrigation can affect the bond strength of adhesive systems on pulp chamber lateral walls. Clinically, low EDTA concentrations can be recommended if self-etch adhesives have been selected.

Macroscopic description of teeth of Azara's agouti (Dasyprocta azarae)

The teeth of Azara's agouti (Dasyprocta azarae) were described macroscopically in order to provide biological data on one of the largest wild rodents of the Americas. Radiography was taken on six heads and the teeth were described. Enamel surrounds the coronal dentin, projects to the roots and is present as parallel inner laminae in buccolingual direction. The dentin is located among the enamel laminae and surrounds the pulp horns. The cementum is located internally to the enamel laminae. On the lingual surface, the cementum and dentin are the outer elements.

Endodontic Management in a Patient with Vitamin D–resistant Rickets

Introduction Hypophosphatemic vitamin D–resistant rickets (VDRRs) is a metabolic bone disease caused by abnormalities in the vitamin D receptive system or in phosphate and calcium metabolism. This condition occurs in growing skeleton affecting bone and dentin mineralization, resulting in systemic and oral manifestations. Methods A 15-year-old boy was referred to the private clinic for endodontic treatment in #9. His medical history revealed VDRR disease. The dental findings were multiple periapical lesions in several teeth without obvious reason such as caries or trauma. The radiographic examination showed short roots, enlarged pulp chambers with longer pulp horns, thin dentin and enamel, missing or poorly defined lamina dura, and abnormalities in the cementoenamel junction, all pathognomonic features of the disorder. Conservative endodontic treatment was completed in all teeth with pulp necrosis and rarefactions. Results A 6-month, 1-year, and 2-year follow-up radiographic examination revealed progressive improvement with bone reconstruction without any clinical symptoms. Conclusions Early diagnosis, conventional treatment, and continuous radiographic examination are important factors in improving dental alterations in patients with VDRRs.

A study of sub-occlusal secondary dentine thickness in overgrown equine cheek teeth

The presence of cheek tooth loss or defects, with subsequent overgrowth of the opposing teeth, is common in horses. Little is known about the factors that control the deposition of sub-occlusal secondary dentine (SO2D) in normal equine teeth, but these are likely to include stimulation of the occlusal surface. There appears to be no information on the possible alterations to this process when teeth develop overgrowths and, consequently, of the net effect on SO2D thickness caused by reduced stimulation of the occlusal surface and of absent/reduced normal occlusal wear (attrition). Knowledge of the likely thickness of SO2D in overgrown teeth may help reduce the risks of pulp horn exposure or thermal damage during therapeutic reduction of overgrowths. This study utilised 24 permanent cheek teeth (CT) with overgrowths (mean overgrowth height: 9.5 mm; range, 3.4-17.9 mm), and 18 control CT obtained from 15 horses of different breeds and ages. The thickness of SO2D was measured above 94 matched pulp horns in control and overgrown CT and showed a mean value of 12.14 mm (range 1.87-36.02 mm) in overgrown teeth and of 10.25 mm (range 2.64-17.26 mm) in controls. There was no significant difference between SO2D thickness in overgrown (mean 11.38 mm) and control (11.41 mm) mandibular CT, but SO2D was significantly thicker in overgrown (mean 12.57 mm) as compared to control maxillary (9.41 mm) CT. A comparison of SO2D thickness above the 94 matched pulp horns in overgrown and control teeth showed that 49% (46/94) of pulps in overgrown teeth had less SO2D overlying them than had control teeth. Of major clinical relevance was that the height of dental overgrowths was greater than SO2D thickness over one or more pulp horns in 14/24 overgrown teeth. Consequently, reduction of these overgrown teeth to the level of adjacent normal-height teeth would cause occlusal pulp exposure in 58% of teeth, in addition to possible thermal damage to additional pulp horns. It was concluded that equine CT overgrowths should be gradually reduced, by a few millimetres at a time, over a prolonged period.

Expression patterns of Sema3F, PlexinA4, -A3, Neuropilin1 and -2 in the postnatal mouse molar suggest roles in tooth innervation and organogenesis

Objective. Semaphorins form a family of axon wiring molecules but still little is known about their role in tooth formation. A class 3 semaphorin, Semaphorin3F (Sema3F), besides acting as a chemorepellant for different types of axons, controls a variety of non-neuronal developmental processes. Materials and methods. Cellular mRNA expression patterns of Sema3F as well as neuropilin 1 (Npn1), neuropilin 2 (Npn2), plexinA3 and plexinA4 receptors were analyzed by sectional in situ hybridization in the mouse molar tooth during postnatal days 0–7. The expression of the receptors was studied in PN5 trigeminal ganglia. Results. Sema3F, Npn1, -2 and plexinA4 exhibited distinct, spatiotemporally changing expression patterns, whereas plexinA3 was not observed in the tooth germs. Besides being expressed in the base of the dental mesenchyme Sema3F, like plexinA4, Npn1 and -2, was present in the ameloblast cell lineage. Npn1 and Npn2 were additionally seen in the pulp horns and endothelial cells and like PlexinA4 in the developing alveolar bone. Npn1, plexinA3 and -A4 were observed in trigeminal ganglion neurons. Conclusions. Sema3F may act as a tooth target-derived axonal chemorepellant controlling establishment of the tooth nerve supply. Furthermore, Sema3F, like Npn1, -2 and plexinA4 may serve non-neuronal functions by controlling the development of the ameloblast cell lineage. Moreover, Npn1 and Npn2 may regulate dental vasculogenesis and, together with PlexinA4, alveolar bone formation. Further analyses such as investigation of transgenic mouse models will be required to elucidate in vivo signaling functions of Sema3F and the receptors in odontogenesis.

The Expression of GM-CSF and Osteopontin in Immunocompetent Cells Precedes the Odontoblast Differentiation Following Allogenic Tooth Transplantation in Mice

Dental pulp elaborates both bone and dentin under pathological conditions such as tooth replantation/transplantation. This study aims to clarify the expression of granulocyte macrophage colony-stimulating factor (GM-CSF) and osteopontin (OPN) in the process of reparative dentin formation by allogenic tooth transplantation using in situ hybridization for OPN and immunohistochemistry for GM-CSF and OPN at both levels of light and electron microscopes. Following the extraction of the mouse molar, the roots and pulp floor were resected and immediately allografted into the sublingual region. On days 1 to 3, immunocompetent cells such as macrophages and dendritic cells expressed both GM-CSF and OPN, and some of them were arranged along the pulp-dentin border and extended their cellular processes into the dentinal tubules. On days 5 to 7, tubular dentin formation commenced next to the preexisting dentin at the pulp horn where nestin-positive odontoblast-like cells were arranged. Until day 14, bone-like tissue formation occurred in the pulp chamber, where OPN-positive osteoblasts surrounded the bone matrix. These results suggest that the secretion of GM-CSF and OPN by immunocompetent cells such as macrophages and dendritic cells plays a role in the maturation of dendritic cells and the differentiation of odontoblasts, respectively, in the regenerated pulp tissue following tooth transplantation.

An anatomical study to evaluate the risk of pulpar exposure during mechanical widening of equine cheek teeth diastemata and ‘bit seating’

Cheek teeth (CT) diastemata are a major equine dental disorder that can be treated by mechanically widening the diastemata. There is limited anatomical knowledge of the spatial relationships of the individual pulps to the adjacent interproximal surfaces; on the risks of exposing the 6th pulp horn when performing the clinically unproven 'bit seating' procedure on Triadan 06s. To describe the anatomical relationships between the occlusal and interproximal surfaces of CT and the adjacent pulp horns; and between the 6th pulp horn and the occlusal and rostral surfaces of Triadan 06s. The CT from 30 skulls of horses subjected to euthanasia for non-dental reasons were sectioned to expose the rostrally and caudally situated pulp horns to allow the anatomical relationships between the pulp horns and the occlusal and interproximal aspects of the CT to be assessed. Pulp horns were mean ± s.d. of 5.74 ± 1.45 (range 1.3-10.8 mm) from the nearest interproximal surface, with 5.3% of pulp horns being <3.5 mm from the interproximal surface. In contrast to expectations, pulps tended to became closer to the interproximal surface (and also to the occlusal surface) with increasing age. Teeth with physiologically tall clinical crowns, and also those in the Triadan 09 position had pulps that were closer to the interproximal surfaces than the remaining CT. The more caudally situated pulp horns, i.e. in particular, the 4th maxillary and 5th mandibular pulp horns were closer to the interproximal surfaces than the remaining pulp horns and these pulp horns also had the thinnest sub-occlusal secondary dentine. Pulps that were close to the interproximal surface were also found to be close to the occlusal surface of the CT. While diastema widening is theoretically safe between the majority of CT, a small proportion of pulp horns are only 1.3 mm from an interproximal surface and others lie just 1.6 mm beneath the occlusal surface, and such pulps are at risk of pulpar exposure and to thermal injury during this procedure. The risk of pulpar exposure increases when dental tissue is removed from the caudal aspects of CT.

Concommitant occurance of dens invaginatus and talon cusp: A case report

PURPOSE: Morphological dental anomalies of the maxillary lateral incisors are relatively common. However, their simultaneous occurrence is a relatively rare event. We report a case of dens invaginatus and talon cusp concurrently affecting maxillary lateral incisors. The etiology, pathophysiology, association with other dental anomalies, as well as various treatment modalities of these anomalies are discussed. CASE DESCRIPTION: An 18-year-old male patient reported with a complaint of crowding of maxillary front teeth. On intraoral examination, permanent dentition with Class I malocclusion with anterior crowding was observed. Tooth 12 showed a radiopaque invagination from a lingual pit but confined to the crown of the tooth. This invagination was approximately circular with a central core of radiolucency, which was consistent with the diagnosis of a dens invaginatus type I. Tooth 22 showed the talon cusp as a typical inverted cone with enamel and dentine layers and a pulp horn extending only into the base of the cusp. Talon cusp was treated by prophylactic enameloplasty to avoid plaque accumulation, the deep lingual pit was sealed using composite resin and regular clinical and radiographic follow-up was advised. Patient was scheduled for orthodontic treatment to correct crowding of maxillary anterior teeth. CONCLUSION: We emphasize the fact that detailed clinical and radiographic examination of the maxillary lateral incisors is vital in avoiding complications.

The anatomy of the root canal system of three‐rooted maxillary premolars analysed using high‐resolution computed tomography

To analyse the anatomy of the root canal system of maxillary premolars with three distinct roots using high-resolution computed tomography (μCT). Ten three-rooted human maxillary premolars were scanned transversally from crown to apex at 42μm intervals using a high-resolution desktop μTC system (Skyscan 1072). The images were processed and analysed for the following features: cross section of the roots and canals in the apical, middle and coronal thirds; location of the apical foramen; distance from the pulp chamber roof to the bifurcation and trifurcation of the canals and anatomic variations of the root canal system. The results were expressed descriptively. The cross-sectional shape of canals was heterogeneous along the length of the roots. The location of the apical foramen varied, tending to lie palatally or distally. The buccal pulp horn was larger than the palatal. The mean distance from the most cervical region of the pulp chamber roof to the bifurcation and trifurcation of the canals was 3.13 and 5.08mm, respectively. Features of the internal anatomy of the pulp cavity of three-rooted maxillary premolars were identified with the use of μCT. The results revealed the heterogeneity of three-rooted maxillary premolars.

The effect of acid etchant type and dentin location on tubular density and dimension

Coronal and radicular dentin may react differently to the type of acid treatment used when bonding to these substrates. The purpose of this study was to characterize and compare dentin morphology, tubular density, and cross-sectional area in deep coronal (around an exposed pulp horn) and root canal dentin at the cervical third in the intact state and after acid etching with phosphoric acid or self-etching dentin primer. Extracted, human, caries-free premolars were fixed. Smear layer-free sections (control) were obtained and divided into 3 groups: left intact, etched with phosphoric acid, or etched with a self-etching primer from a dentin bonding system. Specimens were examined using scanning electron microscopy. Tubular density and cross-sectional area were determined from the images using software. Values were submitted to multifactorial ANOVA (alpha=.05). Tubular density was not significantly affected by acid type or by dentin location. Acid type significantly (P<.001) affected tubular cross-sectional area: phosphoric acid > self-etching resin > intact dentin, irrespective of dentin location. All acid-treated specimens showed demineralization, and irregular surface morphology was not affected by either acid treatment. Tubular density was not significantly different between deep coronal and root canal dentin nor affected by acid treatment type. Tubular cross-sectional area did not differ between deep coronal or root canal dentin, regardless of acid treatment. Both acid types significantly increased tubular cross-sectional area at both dentin locations, phosphoric acid to a greater degree than the self-etching primer. Root canal dentin did not display peritubular dentin.

A study of the thickness of cheek teeth subocclusal secondary dentine in horses of different ages

There is limited knowledge on the thickness of subocclusal secondary dentine in equine cheek teeth (CT). Subocclusal secondary dentine is of consistent thickness above different pulp horns in individual horses and its thickness increases with age. 408 permanent CT were extracted post mortem from 17 horses aged 4-30 years, with no history of dental disease. The CT were sectioned longitudinally in the medio-lateral (bucco-palatal/lingual) plane through each pulp horn, and the thickness of the secondary dentine overlying each pulp horn was measured directly. The subocclusal thickness of secondary dentine above the pulp horns of CT varied from a mean thickness (above all pulp horns) of 12.8 mm (range 5-33 mm) in a 4-year-old to 7.5 mm (range 2-24 mm) in a 16-year-old horse. There was wide variation in the depth of subocclusal secondary dentine above different pulp horns, even within the same CT. In contrast to expectations, occlusal secondary dentine thickness did not increase with age. There were no significant differences in occlusal secondary dentine thickness between rostral and caudal, or medial and lateral aspects of the CT, or between contralateral CT. Mandibular CT had significantly thicker subocclusal secondary dentine than maxillary CT. Pink coloured secondary dentine was sometimes found 1-3 mm occlusal to the pulp horn in sectioned CT and this was likely caused by artefactual blood staining from the underlying pulp during sectioning. The thickness of subocclusal secondary dentine varies greatly between individual pulp horns, teeth and individual horses and can be as low as 2 mm over individual pulp horns. Due to the great variation in the thickness of subocclusal secondary dentine between horses, and even between pulp horns in individual CT, there is a risk of exposure or thermal damage to pulp and thus of apical infection, even with modest therapeutic reductions of CT occlusal overgrowths. In the light of these findings, great care should be taken when reducing equine CT overgrowths and larger dental overgrowths should be reduced in stages.

Occlusal fissures of the equine cheek tooth: Prevalence, location and association with disease in 91 horses referred for dental investigation

Fissures of the occlusal surface of the equine cheek tooth are poorly understood and their association with dental disease is unknown. To describe the prevalence and location of occlusal fissures in the cheek teeth (CT) of a group of horses referred for dental investigation/treatment, and determine association with intercurrent dental disease. Digital video recordings of oral endoscopic examinations for all horses referred to the Rossdales Equine Hospital for dental investigation from November 2006 to June 2009 were reviewed. Location of occlusal fissures in relation to both Triadan tooth position and pulpar secondary dentine was recorded; direction of fissure and concurrent involvement of enamel was also documented. The CT location considered at the time of examination to be the primary site/s of disease was correlated with presence of fissures on these teeth. 91 cases meeting the inclusion criteria were identified. Occlusal fissures were documented in 58.2% (53/91) cases, with a total of 227 CT being affected. Fissures were most prevalent mid-arcade. The majority (92.1%) of fissures in maxillary CT were associated with the caudal palatal pulp horn. Fissures in mandibular CT were predominantly associated with the buccal pulp horns (95.7%). There was no significant difference in the median number of CT with fissures in relation to gender. There was no correlation between age (r(2)= 0.01) of horse and number of CT with fissures. A significantly greater number of CT with multiple occlusal fissures was found in mandibular compared to maxillary arcades. No correlation was found between presence of fissures and location of individual CT considered to be primarily responsible for presentation. Occlusal fissures in this group of animals were common and not correlated to primary site of dental disease. In horses subjected to dental investigation, occlusal fissures of the cheek teeth should not be considered an indicator of tooth compromise. Location and direction of fissure propagation in most cases is inconsistent with occlusal fissures being causally implicated in slab fractures of cheek teeth, although site predilection may indicate a possible association with masticatory forces.

Three-dimensional analysis of pulp chambers in mandibular first deciduous molars

In crown restoration, it is important to understand the internal anatomical feature of each tooth, as the morphology of human deciduous teeth is particularly complex. The purpose of this study was to clarify threedimensionally the topographic relationship between the crown contour and the pulp chamber of the mandibular first deciduous molars using a micro-CT system. Fifteen mandibular first deciduous molars obtained from the dried skulls of Indian children in the deciduous dentition period were used as specimens. Three-dimensional reconstructed images were reproduced by combining the two-dimensional slice imaging data using a micro-CT system. Crown contours and shapes of the pulp chamber were observed from various directions. In addition, the thickness of tooth substance at each pulp horn was also measured. In observations of the topographic relationship between the crown contour and the pulp chamber, the pulp horn of the mesiobuccal pulp chamber was found to project the most to the cusp side. The distance between the pulp horn and enamel surface was also shortest (2.45 ± 0.30 mm) in this region. Furthermore, in teeth with a deep, wide trigonid notch, the lateral wall of the mesiobuccal pulp chamber projected in the mesial direction. These results suggest that in preparation of cavities in mandibular first deciduous molars, close attention must be focused on pulp exposure in the pulp horn of the mesiobuccal pulp chamber. In addition, the lateral wall of the mesiobuccal pulp chamber should be noted in teeth with the deep, wide trigonid notch.

Two‐ and three‐dimensional computed tomographic anatomy of the enamel, infundibulae and pulp of 126 equine cheek teeth. Part 1: Findings in teeth without macroscopic occlusal or computed tomographic lesions

Dental disorders are of major clinical importance in equine practice; however, the knowledge of normal dental anatomy, especially that of the pulp remains incomplete. Computed tomography (CT) is being used increasingly in the diagnosis of dental disease, although the normal 2- (2D) and 3-dimensional (3D) CT anatomy has not yet been fully described. To describe the 2D and 3D CT appearance of the enamel, infundibulae and pulp of normal equine cheek teeth. One-hundred-and-twenty-six cadaveric cheek teeth with eruption ages of 0.5-19 years were evaluated; CT scans of each tooth were performed after occlusal surface examination with a dental probe. Three-dimensional reconstructions of the enamel, infundibulae and pulp were created from the CT scans using greyscale thresholding and subsequent polynomial meshing. Each tooth was sectioned coronally or axially into serial slices using a band saw and the sections compared to the corresponding CT images. The CT reconstructions enabled the systematic description of the pulpar anatomy of the mandibular and maxillary cheek teeth in 3D, which has not been described in detail previously. The number of interpulpar communications between pulp horns and the pulpar volume of each tooth was shown to decrease with increasing age. The interpulpar communications of the maxillary cheek teeth were found to be of greater complexity and variety in comparison to their mandibular counterparts. Mandibular and maxillary cheek teeth showed different, but consistent patterns in their pulpar and enamel morphology. The detailed description of the normal 2D and 3D CT appearance of equine cheek teeth provides a reference basis for the diagnosis of dental disease with CT. Additionally, in depth knowledge of the pulpar anatomy of the equine cheek teeth is an essential prerequisite if endodontic therapy is to develop further in the future.