Dog Dental Pulp Research Articles

Microscopic Alterations of the Dental Pulp in Surgically Extracted Teeth of Dogs.

Microscopic alterations in the dental pulp of dogs have not been extensively studied. The aim of this study was to investigate microscopic alterations of the dental pulp in dogs' teeth. One hundred and ten surgically extracted teeth (20 incisors, 23 canines, 28 premolars, and 39 molars) from 74 dogs, of different ages, with a history of chronic periodontitis (66 dogs), periapical abscesses (2 dogs), pulpitis (2 dogs), oral cavity neoplasms (2 dogs), dens invaginatus (1 dog), and dental fractures (1 dog) were included. Eight-one maxillary and 29 mandibular teeth were included. Coronal, radicular, and coronal plus radicular calculus were present in 28.2%, 17.3%, and 54.5% of the teeth, respectively. In total 78 teeth (71%) had pulp alterations, including fibrosis (26%), calcification (14%), necrosis associated with the absence of odontoblasts (14%), presence of predentin and dentin inside the cavity (8%), odontoblastic hyperplasia (3%), pigmentation (3%), pulpitis (2%), and pulp stones (1%). Forty-nine (60.5%) of the maxillary teeth and all of the mandibular teeth had pulp alterations. The premolars were most affected, and the molars least affected, by pulp alterations. Pulp fibrosis, calcification, and necrosis were observed in teeth irrespective of the distribution of dental calculus.

The Use of Lactide Polymers in Bone Tissue Regeneration in Dentistry-A Systematic Review.

(1) Background: Different compositions of biodegradable materials are being investigated to successfully replace non-resorbable ones in bone tissue regeneration in dental surgery. The systematic review tried to address the question, "Can biodegradable polymers act as a replacement for conventional materials in dental surgery procedures?" (2) Methods: An electronic search of the PubMed and Scopus databases was conducted in October 2022. The following keywords were used: (lactide polymers) and (hydroxyapatite or fluorapatite) and (dentistry) and (regeneration). Initially, 59 studies were found. Forty-one studies met the inclusion criteria and were included in the review. (3) Results: These usually improved the properties and induced osteogenesis, tissue mineralisation and bone regeneration by inducing osteoblast proliferation. Five studies showed higher induction of osteogenesis in the case of biomaterials, UV-HAp/PLLA, ALBO-OS, bioresorbable raw particulate hydroxyapatite/poly-L-lactide and PLGA/Hap, compared to conventional materials such as titanium. Four studies confirmed improvement in tissue mineralisation with the usage of biomaterials: hydroxyapatite/polylactic acid (HA/PLA) loaded with dog's dental pulp stem cells (DPSCs), Coll/HAp/PLCL, PDLLA/VACNT-O:nHAp, incorporation of hydroxyapatite and simvastatin. Three studies showed an acceleration in proliferation of osteoblasts for the use of biomaterials with additional factors such as collagen and UV light. (4) Conclusions: Lactide polymers present higher osteointegration and cell proliferation rate than the materials compared. They are superior to non-biodegradable materials in terms of the biocompability, bone remodelling and healing time tests. Moreover, because there is no need of reoperation, as the material automatically degrades, the chance of scars and skin sclerosis is lower. However, more studies involving greater numbers of biomaterial types and mixes need to be performed in order to find a perfect biodegradable material.

Impact of a New Silicate-Based Capping Material on Healing Potentiality of Traumatically Exposed Healthy Dog's Dental Pulp

The aim of the current study was to evaluate the impact of a new silicate-based capping material on healing potential of traumatically exposed healthy dog's dental pulp. Materials and Methods: Two pulp capping materials were evaluated in this study; Mineral trioxide aggregate (MTA), and Five mineral oxides (5MO). Glass ionomer as overlying restorative material. Six adult healthy dogs with intact permanent dentition were selected for the study. A total of sixteen anterior teeth were used in each dog. Both pulp capping materials were used in the same dog. Class V cavities were prepared on the teeth. After pulp exposure, the pulp capping materials were applied directly to the exposed pulp. All cavities were sealed with glass ionomer restorative material. The used six dogs were divided into two groups; three dogs each, according to the capping periods to 7 days and 90 days. At the end of each period the dogs were sacrificed by injecting an overdose of pentobarbital sodium. Teeth were separated from bone with immediate sectioning of their roots in the mid-way between cementoenamel junction and apex. The teeth were fixed in 10% neutral buffered formalin. Then the teeth were demineralized in Morse's solution (50% formic acid and 20% sodium citrate) for 3 months. In the last, the teeth were embedded in paraffin wax and serially sectioned buccolingually and stained with hematoxylin-eosin. The specimens were examined under optical light microscope to estimate the amount of pulp inflammation and dentin bridge formation at the interface of the capping materia

Biological effect of Egyptian Propolis on BHK cell line and on dental pulp tissue (An In vitro And In vivo study)

Background: Propolis is a natural material with different biological activities such as anti-inflammatory, antibacterial and antifungal action. The aim of the present work was to evaluate biocompatibility of Egyptian Propolis by using two methods of assessment: the invitro test using Baby hamster kidney cell (BHK) cell line and the invivio study on dental pulp of dogs. Materials & Methods: For the invitro study: ethanol extract of propolis (EEP) was prepared at a concentration of 1mg/ml. A suspension of the cultured BHK cells was placed in 96 multi-well dishes and divided into two groups : control group containing BHK cells without EEP and propolis group containing BHK cells with EEP at a concentration of 1mg/ml. Cell counting was performed at 24 hours, 72 hours and at the seventh day. Mean values were then calculated for each group. The results were then statistically analyzed using ANOVA test. Scanning Electron Microscopy (SEM) was done for both groups at the seventh day. For the invivo study, 2 young healthy adult dogs, of comparable age, 1-1.5 years old and complete set of permanent dentition were used in this study. The canine and first molar of each quadrant were used in this study and second upper molars of each dog was also prepared, forming a sum of 10 sound teeth. A standardized class V cavity was prepared on the facial surface of the selected teeth. All the cavities were restored with resin modified glass ionomer while in half of them Propolis was used as lining material under resin modified glass ionomer. At the end of experimental period after 6 months, dogs were sacrificed. Microsections with 5 μm width were prepared and stained with hematoxylin and eosin. Results: invitro study results showed a significant increase in number of BHK cells of propolis group at 72 hours and at the seventh day when compared to the control group. Scanning electron microscopic examination of BHK cells showed increase in density of BHK cells of propolis group as compared to cells of the control group. Both groups showed uniform spreading and attachment of cells to root surface. Examination of the decalcified stained sections of teeth of propolis group revealed no inflammation, normal tubular pattern of dentin and arrangement of odntoblasts in multiple layers . Presence of line of demarcation between primary and secondary dentine. Conclusion : Egyptian propolis stimulated growth and proliferation of BHK cell in vitro and showed no inflamatory effect on pulp tissue invivo.These results collectively proved the biocomptability and good biological properties of Egyptian propolis and support the application of Egyptian propolis in numerous fields of dentistry.

Mineral trioxide aggregate and portland cement for direct pulp capping in dog: a histopathological evaluation.

Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. Histopathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tissue were evaluated in the present study.Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposed with a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Portland cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%.Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral trioxide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Although the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45%) and the least increase in fibrous tissue were observed adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant.Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp capping in dog teeth.

Isolation and identification of Beagle dog dental pulp stem cells

To identify the existence of the dental pulp stem cells in Beagle's pulp tissue by using the same methods of isolating and culturing the human dental pulp stem cells. Pulp tissue was extirpated from the crown and root of the Beagle's healthy permanent tooth, and digested by dispase for cell culture. Classical identification methods of mesenchymal stem cells including observation of biological characteristics, capacity of multilineage differentiation, and expression of specific markers associated with mesenchymal stem cells were applied to verify the existence of Beagle's dental pulp stem cells. A clonogenic, rapidly proliferative population of cells were isolated from Beagle' pulp tissue. Under the same culture condition, the Beagle's dental pulp stem cells had a significant higher colony-forming unit-fibroblast (CFU-F) formation rate (150 colony/10(4) cells) than the dental pulp cells derived from the human pulp tissue (60 colony/10(4) cells). These cells also had the multilineage differentiation ability. They could be induced to form mineralized nodules, lipid droplets and chondrocytes. Furthermore these cells expressed the mesenchymal stem cell markers including STRO-1, CD146, alkaline phosphatase, nestin, vimentin and cytokeratin-18. There are dental pulp stem cells in the Beagle's pulp tissue.

Absence of lymphatic vessels in the dog dental pulp: an immunohistochemical study.

In spite of numerous investigations it has not been precisely determined whether lymphatic vessels are present in the dental pulp of dogs. Therefore, this study attempted a specific immunohistochemical detection of lymphatic endothelium. The canine teeth of 19 healthy beagle dogs were dissected into three segments (apical, intermediate and occlusal). After decalcification, specimens were embedded in paraffin wax and histologic cross-sections were stained immunohistochemically using a reliable antibody (anti-Prox-1) against the homeobox transcription factor Prox-1, which is located within the nucleus of lymphatic endothelium. Anti-Prox-1 reacted positively with canine control tissues (lymph nodes, gingiva, nasal mucosa), but showed no staining in tissue sections of the dental pulp. The dog dental pulp contained no vascular structures lined with lymphatic endothelium. This suggests that drainage of interstitial fluid makes use of other routes, i.e. extravascular pathways.

Establishment of Immortal Dog Dental Pulp Cell Line and Analysis of Its Characteristics

Establishment of Immortal Dog Dental Pulp Cell Line and Analysis of Its Characteristics

Morphologic and hemodynamic analysis of dental pulp in dogs after molar intrusion with the skeletal anchorage system

We have successfully treated skeletal open bite by intruding posterior teeth with the skeletal anchorage system. Our aim in this study was to morphologically and hemodynamically evaluate the changes in pulp tissues when molars are radically intruded. The mandibular fourth premolars of 9 adult beagle dogs were divided into 3 groups: a sham operated group (n = 6, 3 dogs), 4-month intrusion group (n = 6, 3 dogs), and a further 4-month retention group (n = 6, 3 dogs). We evaluated the morphological changes of the pulp and dentin-the amount of vacuolar degeneration in the odontoblast layer, the predentin width and nervous continuity in the pulp tissue, and the pulpal blood-flow response evoked by electrical stimulation in the dental pulp. Extreme molar intrusion with the skeletal anchorage system caused slight degenerative changes in the pulp tissue, followed by recovery after the orthodontic force was released. Circulatory system and nervous functions were basically maintained during the intrusion, although a certain level of downregulation was observed. These morphologic and functional regressive changes in the pulp tissue after molar intrusion improved during the retention period. Histologic changes and changes in pulpal blood flow and function are reversible, even during radical intrusion of molars.

In Vivo Effect of Calcium Phosphate Biomaterials on Dog Dental Pulp

ABSTRACTExogenous ideal delivery system for biologically active molecules is under intensive investigation. In the present study it was aimed to test the availability of different calcium phosphate biomaterials (CPBs), hydroxyapatite (HA), beta tricalcium phosphate (TCP), and a combination of these (TCP+HA) as dental pulp capping systems on healing of dog dental pulp. Experimentally perforated dental pulps of 16 premolar and molar teeth in a beagle dog were capped with CPBs. Calcium hydroxide (CH) was used as positive control. Thirty days after the operation, teeth were extracted and examined by routine histological techniques. While in HA and TCP group the pulp tissue displayed severe inflammatory response, prompted healing of the pulp tissue in TCP+HA group was seen. Complete bridge of reparative dentin formation was obvious in TCP+HA and CH groups.This study suggested that TCP+HA induced dentinogenic effect in the pulp cells of dog teeth. TCP+HA might serve as an ideal calcium phosphate pulp capping biomaterial to induce initial healing response and it might has a capacity for being a good carrier for biologically active dentinogenic molecules.

Histological evaluation of odontoblast-like cells response after capping application of calcium hydroxide and hydroxilapatite in dog’s pulp

This study was conducted to observe the response of dog's dental pulp to hydrpxylapatite (Hap) and calcium hydroxide when used as pulp capping materials. After the pulps of 22 teeth were exposed, they were capped with either Hap or calcium hydroxide. Histological analysis was performed 8 weeks after treatment. Results showed that pulp exposure caused irreversible injury of odontoblasts, which were subsequently replaced by similar, odontoblast-like cells. These cells were able for reparative dentin bridge formation in 6 cases treated with calcium hydroxide and almost all the cases treated with hydroxylapatite. The presence of odontoblast-like cells seemed to be crucial for reparative dentinogenesis. The capping material was of less importance. In conclusion neither calcium hydroxide nor hydrxylapatite had completely satisfied all the requirements of an ideal capping material, although Hap can be recognized as a superior alternative to calcium hydroxide.

Microscopic analysis of dog dental pulp after pulpotomy and pulp protection with mineral trioxide aggregate and white Portland cement

Considering previous studies on the similarity between the chemical composition of the mineral trioxide aggregate and the Portland cement, the purpose of this study was to investigate the pulp response of dog's teeth after pulpotomy and direct pulp protection with MTA Angelus and white Portland cement. Thirty eight pulp remnants were protected with these materials. One hundred and twenty days after treatment, the animals were sacrificed and the specimens removed and prepared for histological analysis. Both materials demonstrated the same results when used as pulp capping materials, inducing hard tissue bridge formation and maintaining pulp vitality in all specimens. The MTA Angelus and the white Portland cement showed to be effective as pulp protection materials following pulpotomy.

Effects of Flumetazone on Exposed Dental Pulp of Dogs

home Acta Veterinaria Brno Journal of the University of Veterinary Sciences Brno, Czech Republic Search:

Defence reaction in dental pulp after pulp capping and partial pulpectomy in dogs.

The dental pulp was capped indirectly or directly, or partial vital pulpectomy was performed on the 12 functionally most important teeth of 24 beagle dogs. For pulp capping, calcium hydroxide was used, followed by zinc phosphate as a lining, and the preparation was restored with amalgam or composite material. Histological sections were prepared and examined for degree and type of pulp inflammation (hyperaemia, pulpitis, necrosis or gangrene). Degenerative changes of dental pulp (vacuolation, calcification, amyloid or hyaline changes) were also determined. For indirect pulp capping the width of predentine in crown and root dental pulp was measured, and for direct pulp capping and partial pulpectomy (vital pulpotomy) the width and quality of the dentinal bridge were graded. The radical method of partial vital pulpectomy of the coronal part of the dental pulp in dogs produced better quality and continuity of the dentinal bridge than the less radical method of direct pulp capping. This was particularly obvious in small single root teeth such as incisors.

Stimulation of proliferation and differentiation of dog dental pulp cells in serum-free culture medium by insulin-like growth factor

Insulin, insulin-like growth factors (IGF) I and II are considered to play an important part in the growth and differentiation of dental pulp cells. The present study examined the effects of these factors on pulp cells in serum-free culture conditions. The DNA content and alkaline phosphatase (ALPase) activity of dog pulp cells increased when they were cultured in a serum-free medium supplemented with transferrin, yolk lipoprotein and basic fibrobrast growth factor (TYF medium). The pulp cells produced type I collagen but not type III, suggesting that they might proliferate and differentiate into odontoblast-like cells in a serum-free culture. Both IGF-I and IGF-II enhanced the ALPase activity of pulp cells cultured in TYF medium to an equivalent level, but a higher concentration of IGF-II was necessary to produce a similar effect on DNA synthesis to that of IGF-I. Insulin dose-dependently enhanced DNA synthesis and increased ALPase activity, but its effects were weaker than those of the IGFs. These findings suggest that IGF-I might have a primary role in the growth and differentiation of pulp cells.

Effects of recombinant basic fibroblast growth factor, insulin-like growth factor-II and transforming growth factor- β1 on dog dental pulp cells in vivo

The effects of recombinant basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF)-II and transforming growth factor (TGF)- β 1 on dental pulp cells were investigated by light and transmission electron microscopy after their implantation for 1 and 3 weeks at central sites of mechanically exposed pulps in dog molar and canine teeth. The implants were Millipore filters that have been soaked with solutions containing 100 or 500 ng/ml of bFGF or IGF-II or 100 ng/ml of TGF- β 1. Control filters were soaked with dog albumin. No changes in cell organization or matrix synthesis were seen after implantation of control filters. Groups of columnar, polarized cells with numerous mitochondria and Golgi elements or elongated cells unassociated with any matrix deposition were demonstrated after 1 or 3 weeks, respectively, in close proximity to the filters that had been soaked with bFGF solution; at a distance from these implants enhanced formation of an osteotypic matrix was seen beneath the exposure site. No particular response was found in close proximity to the filters that had been soaked with IGF-II solution after 1 or 3 weeks implantation but thick zones of osteodentine were found beneath the exposure site and at adjacent circumferential dentine sites. Numerous elongated, polarized cells with long cytoplasmic extensions invading the filter pores were consistently seen after 1 week in close proximity to the filters that had been soaked with TGF- β 1 solution. After 3 weeks implantation of these filters, deposition of a tubular matrix surrounding the implants was seen in association with the highly elongated odontoblast-like cells, while enhancement of circumferential dentine formation was also found at adjacent peripheral sites. These experiments demonstrate that TGF- β 1 when implanted for short term periods at central pulp sites exerted dentine-specific effects, inducing differentiation of odontoblast-like cells and stimulating primary odontoblasts. Implantation of bFGF and IGF-II did not result in reparative dentine formation, but did stimulate osteotypical matrix deposition at a distance from the implants.

Nitric oxide synthase containing nerves in the cat and dog dental pulp and gingiva

In a previous study we found that nitric oxide (NO) plays an essential role in the hemodynamic regulation of the feline dental pulp. However, no evidence for the presence of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) containing nerve fibers was found in the rat and cat dental pulps. In the present study, we are first to report the presence of a small number of NADPH-d positive and/or NO synthase immunoreactive perivascular and solitary varicose axons in the dental pulp and abundant number of similar axons in the gingiva of cats and dogs. These fibres may travel within the inferior alveolar nerve and might participate in sensory (i.e. pain) as well as in autonomic (i.e. regulation of blood flow) innervation of the dental pulp and gingiva.

Inability of calcium hydroxide to induce reparative dentinogenesis at non-peripheral sites of dog dental pulp.

The ability of 2 calcium hydroxide-containing materials to induce initiation of reparative dentinogenesis was tested at sites remote from the dentinogenically-active regions of the pulp periphery. Pieces of the cements, Dycal and Life, were implanted in central parenchymal sites of dog dental pulps for periods of 6, 14 and 42 days, respectively. Similar pieces were placed in peripheral capping sites as controls. The responses were analyzed by light and transmission electron microscopy. Induction of tubular dentin matrix lined with elongated and polarized odontoblast-like cells was only seen at peripheral capping sites. In response to the centrally implanted cements, only atubular hard tissue with lining fibroblast-like cells was deposited.

Immunolocalization of fibronectin during the early response of dog dental pulp to demineralized dentine or calcium hydroxide-containing cement

The role of fibronectin during the events initiating the post-developmental histogenesis of dentine was investigated by exposing the pulp to implants of autogenous demineralized dentine or calcium hydroxide-containing cement for short periods. Implants exposed for 3 days were processed for immunoelectron-microscopic analysis of fibronectin adsorption on to their surfaces. The localization of fibronectin in the critical area of interaction was examined by immunofluorescence 6, 14 and 21 days after implantation. Heavy adsorption of fibronectin on to the dentine implants and the crystalline structures that had been deposited on the cement implants was demonstrated. Positive fluorescence was consistently seen around dentine implants. Strongly immunopositive fibroblast-like cells and weakly reactive, differentiating odontoblast-like cells were found in association with the implanted matrix. Uncalcified matrix secreted by the polarized or non-polarized cells was consistently rich in fibronectin. Fibroblast-like cells exhibiting intense immunoreaction only at 14 and 21 days were mainly associated with the crystalline precipitates on the cement surfaces or within the surrounding pulp. The findings indicate that the specific inductive effects of demineralized dentine on pulp cells are initiated by exposure of the pulp to a fibronectin-containing surface; adhesion of pulp cells and synthesis of a fibronectin-rich matrix characterize the development of new dentine. The reparative response to non-specific inductive influences such as calcium hydroxide seems to be mediated by progressive enhancement of fibronectin synthesis in pulp cells.

Dentinogenic activity of allogenic plasma fibronectin on dog dental pulp.

The response of ectomesenchymal cells of dog dental pulp to implantation of Millipore filters supplemented with bovine plasma fibronectin was evaluated after observation periods of one or four weeks. Two concentrations of plasma fibronectin were used (0.2 and 1 mg/mL). Experiments also included implants treated with control solutions (PBS or 1 mg/mL of dog albumin). Formation of a layer of elongated, polarized cells was demonstrated in direct contact with the implants treated with 1 mg/mL of plasma fibronectin solution, after one week post-operatively. Microfilamentous organization and orientation of rough endoplasmic reticulum was observed mainly in the supranuclear zone of the polarized cells. Implants treated with the same solution were consistently surrounded by a thick layer of dentinal matrix after four weeks of their exposure to pulp sites. Implants treated with control solutions or with the low concentration of fibronectin never showed any sign of cell polarization and matrix synthesis. These data provide evidence that the pulp cells can express their odontoblastic phenotype in response to a surface containing concentrated fibronectin (even allogenic), without the need of other molecules as exogenous inductive factors.