Dog Teeth Research Articles

Prevalence and types of tooth resorption in dogs with oral tumors

To determine the prevalence and types of tooth resorption in dogs with oral tumors and to compare findings with those for control dogs. 101 dogs with oral tumors and 128 control dogs that did not have oral tumors and for which dental radiographs were available. Exclusion criteria for dogs included systemic disease, long-term administration of anti-inflammatory drugs, traumatic occlusion, severe semigeneralized or generalized periodontitis, and endodontic disease. For each dog with an oral tumor, histologic sections of biopsy specimens of tumors were examined. Dental radiographic images of dogs were examined, and the presence and type of tooth resorption were determined for each tooth. Statistical analyses were performed to compare data regarding prevalence of tooth resorption. Teeth at tumor sites in dogs with nonodontogenic tumors were significantly more frequently affected with external inflammatory resorption, compared with teeth at tumor sites in dogs with odontogenic tumors. Teeth at sites distant from tumors in dogs with oral tumors were 3.2 times as likely to have external surface resorption (OR, 3.2; 95% confidence interval, 1.3 to 7.9) and 83.4 times as likely to have external inflammatory resorption (OR, 83.4; 95% confidence interval, 9.7 to 719.6) as teeth in control dogs. Resorption of teeth at tumor sites and at sites distant from tumors was common in dogs with oral tumors. Results of the present study will contribute to an understanding of the complex effects of oral tumors on local and distant hard tissues.

Height-dependent difference in the expression of naloxone-induced withdrawal jumping behavior in morphine dependent rats

Opiate withdrawal syndrome may motivate opiate seeking and taking. Thus, development of an effective medical treatment for these symptoms is a primary research goal and strongly relies on improved experimental models. Opiate withdrawal syndrome is characterized by several behavioral signs such as wet dog shake, teeth chattering, sniffing, scratching, chewing, diarrhea, rearing, ptosis and jumping. The goal of present study was to evaluate the impact of the cylindrical chamber height on the expression of jumping behavior in morphine dependent rats. Adult male Wistar rats were rendered dependent on morphine by subcutaneous (s.c.) injection of morphine sulfate (10mg/kg) with an interval of 12h for 9 days. On day 10, 2h after morphine injection, rats were injected with naloxone (1mg/kg, i.p.). Naloxone-induced jumping was monitored during a period of 30min in a clear cylindrical Plexiglas test chamber with the floor covered by woodchip. The chambers had the same diameter (35cm), but the heights of chambers were different (30, 40, 50, 60, 70 and 80cm). Incidence and frequency of jumping decreased with increasing the height of the test chambers (P<0.05). Altogether, these findings highlight the possibility of detecting height-dependent difference in the expression of naloxone-induced jumping behavior in morphine dependent rats.

Effect of basic fibroblast growth factor on root resorption after delayed autotransplantation of tooth in dogs

The aim of this study was to investigate the effect of basic fibroblast growth factor (FGF-2) on root resorption after delayed autotransplantation in dogs. Mandibular second and third premolars of beagle dogs were extracted to create sites for autotransplantation. After 2 months, in the experimental sites the first and fourth mandibular premolars were extracted and air dried before autotransplantation with the application of recombinant FGF-2; the control sites received teeth without FGF-2. At 2, 4, or 8 weeks after surgery, the animals were killed and specimens collected and processed for histologic examination. Autotransplantation with FGF-2 yielded formation of new periodontal ligament-like tissues with inserting collagen fibers, associated cementum, and bone. The occurrence of replacement resorption in the FGF-2 treated group was significantly lower than in the control group (P < .01). It was demonstrated that topical application of FGF-2 reduced the occurrence of ankylosis and root resorption after delayed autotransplantation in this experimental model.

A ‘new’ palaeolithic dog from central Europe

AbstractKesslerloch Cave in Switzerland is one of the major Magdalenian sites in Central Europe. During a recent reanalysis of the faunal remains, we identified a cranial fragment and teeth of the domestic dog. The large maxillar fragment was directly dated to 12.225±45 bp (KIA‐33350) or c. 14.100‐14.600 BP. The finds are metrically well below the natural variability of wolves from both Palaeolithic and recent times and even show slight morphological differences to the wild wolves from the site. We argue that the maxilla fragment must now be considered the earliest indisputable directly dated evidence of a domestic dog. Copyright © 2010 John Wiley &amp; Sons, Ltd.

Histopathological analysis of corticosteroid-antibiotic preparation and propolis paste formulation as intracanal medication after pulpectomy: an in vivo study

Intracanal medication in pulpectomy therapy is used between appointments with the objective of reducing pain and inflammatory processes in pulp and periapical tissues. Propolis has been known as a natural antibiotic and has been subject of medical and dental research due to its therapeutic properties such as antibiotic, analgesic and anti-inflammatory effects. ObjectiveThe aim was to carry out an in vivo evaluation of the periapical tissue response to propolis paste when used as an intracanal medication in the teeth of dogs after pulpectomy. Material and Methods72 dog's incisors were selected for the experiment. After biomechanical preparation the root canal was filled with a corticosteroid-antibiotic preparation, experimental propolis paste, non-medicament (negative control) or non-pulpectomy at all (positive control). The medications were left inside the root canal for 7, 14 or 28 days. At the end of the experimental period histological sections were prepared and all laboratories processes for Harris hematoxylin and eosin staining was proceeded followed by the analysis using an optical microscope. Sections were classified according to a score representing the inflammatory events observed: the presence of polymorphonuclear neutrophils, polymorphonuclear eosinophils, lymphocytes and plasma cells, macrophages and/or giant cells, fibrous condensation and abscesses. ResultsThere were statistically significant differences between the tissue reactions caused by the two substances being tested, after different experimental periods, with the periapical tissue that was in contact with propolis paste exhibiting fewer inflammatory reactions in comparison to corticosteroid-antibiotic preparation. ConclusionsThe low tissue responses from propolis paste suggest that this material could be considered as an option for root canal medication after pulpectomy.

Observations Regarding Dental Composite Restorations for Tooth Repair in Dogs

The most common form of tooth repair in human dentistry is filling cavities. Carious decayis uncommon in dogs and almost nonexistent in cats. When found in dogs, cavities are treated bydental restorations(fillings) just as for people.Carious lesions are most frequently identified on theocclusal surfaces of molar teeth in dogs. Dental cavities are often present on both sides and in somedogs they are on the upper and lower dental arches. Early lesions are diagnosed by observation andinvestigation of discolored areas of teeth. Soft enamel may be detected using an explorer probe.These lesions progress into the dentin. The dentin is demineralized by the decay process. Dentalradiographs confirm the presence and the extent of these lesions(Duncan ,2010). The earlier theselesions are diagnosed the greater is ability to save rather than extract these teeth. Early cavitiesinvolve damage to tooth enamel and dentin. Longer term tooth decay results in pulp inflammation,infection. Theese teeth must be treated by root canal therapy or by dental extraction. Carious lesionsmay be restored by performing cavity preparation and the placement composite restorations(fillings). Restorations are performed using a composite resin, which is supplied in a soft, moldableform. After rebuilding a tooth the composite bonds to the tooth and becomes nearly as hard as anormal tooth by exposure to an ultrabright light, called a curing light.

Histopathalogic evaluation of the effect of InGaAlP and GaAs laser therapy on pulpal tissue and dentinal bridge formation following direct pulp cap of dogs teeth

Histopathalogic evaluation of the effect of InGaAlP and GaAs laser therapy on pulpal tissue and dentinal bridge formation following direct pulp cap of dogs teeth

Canine Periodontal Disease Control Using a Clindamycin Hydrochloride Gel

Stabilizing or reducing periodontal pocket depth can have a positive influence on the retention of teeth in dogs. A topical 2% clindamycin hydrochloride gel (CHgel) was evaluated for the treatment of periodontal disease in dogs. The CHgel formulation provides for the sustained erosion of the matrix, but also flows into the periodontal pocket as a viscous liquid, and then rapidly forms a gel that has mucoadhesive properties and also may function as a physical barrier to the introduction of bacteria. A professional teeth cleaning procedure including scaling and root planing was done in dogs with one group receiving CHgel following treatment. Periodontal health was determined before and after the procedure including measurement of periodontal pocket depth, gingival index, gingival bleeding sites, and number of suppurating sites. There was a statistically significant decrease in periodontal pocket depth (19%), gingival index (16%), and the number of bleeding sites (64%) at 90-days in dogs receiving CHgel. Additionally, the number of suppurating sites was lower (93%) at 90-days for the group receiving CHgel. The addition of CHgel effectively controlled the bacterial burden (e.g, Fusobacterium nucleatum) at both day 14 and 90. Gingival cells in culture were shown to rapidly incorporate clindamycin and attain saturation in approximately 20-minutes. In summary, a professional teeth cleaning procedure including root planning and the addition of CHgel improves the gingival index and reduces periodontal pocket depth.

Comparison of Shear Bonding Strength for Two Different Etching Systems in Canine and Human Dentin

Canine dentin has increased size and number of dentinal tubules compared to human dentin. With less intertubular surface area for bonding to composite material in dog teeth, bonding shear strength may be affected negatively. This study was designed to compare the shear bonding strength of canine and human dentin. It also compared bond strength of two different acid etch systems when used with the same composite resin. The shear bond strength of composite cylinders to dentin was measured in 30 extracted canine cuspid teeth and a similar number of human molar teeth. Shear bond strength was 40% greater for human compared with canine dentin. This significantly different (P < 0.05) result validates the hypothesis that dentin bond strength is positively correlated with the area of intertubular dentin. Results also indicated that shear bond strength was greater in the self-etching bond system compared with the etch and rinse system, although this difference was not significant.

Effect of platelet‐derived growth factor‐BB on root resorption after reimplantation of partially denuded tooth in dog

The prognosis for a reimplanted tooth depends largely on the condition of the root. Platelet-derived growth factor (PDGF)-BB has been shown to regenerate periodontal tissue in animal and human clinical studies. However, information regarding the effect of PDGF-BB on tooth reimplantation is limited. The objective of this study was to investigate the effect of PDGF-BB on root resorption after reimplantation of a partially denuded tooth in dog. A total of 15 healthy female beagle dogs were used. Mandibular third and fourth premolars were endodontically treated and then extracted as atraumatically as possible. The coronal portion of each root was carefully scaled and planed. The roots on the right side of the mandible were treated with PDGF-BB and reimplanted, while the roots on the left side served as controls. After 2, 4, or 8 weeks, specimens were collected and processed for histopathological examination. By the 4th week after reimplantation, new periodontal ligament (PDL)-like tissue had formed around the PDGF-BB-treated root surfaces and new bone. By the 8th week, healing of the PDGF-BB-treated roots was characterized by newly formed PDL with inserting attachment formation. In contrast, control roots showed multiple areas of replacement resorption. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA) performed at 2 weeks after reimplantation showed that the number of PCNA-positive cells in the connective tissue area was statistically significantly greater in the PDGF-BB-treated group than in the control group (P < 0.001). The application of PDGF-BB resulted in a significantly lower occurrence and extent of root resorption and ankylosis. These results suggest that the use of PDGF-BB reduces occurrence of ankylosis and root resorption in tooth reimplantation.

Immunohistological Characterization of Newly Formed Tissues after Regenerative Procedure in Immature Dog Teeth

Introduction In a previous report, we showed that 2 types of mineralized tissues were formed in the canal spaces of dogs after tissue engineering treatments of immature teeth with apical periodontitis: (1) dentin- associated mineralized tissue (DAMT) and (2) bony islands (BIs). The objective of this study was to characterize these mineralized tissues. Methods The maturation and organization of collagen matrices in DAMT, BIs, and the interface between DAMT and the dentin wall were characterized using a histochemical method with picrosirius red staining under polarized light microscopy. In addition, the distribution of 2 noncollagenous proteins (ie, dentin sialoprotein and bone sialoprotein) in these tissues was investigated by immunohistochemical methods with specific antibodies. Results The results showed that DAMT is distinct from dentin, bone, or BIs. Although it resembled cementum to an extent showing similar immunoreactivity to the noncollagenous proteins, the organization and maturation of collagen matrix was significantly different from cementum. BIs resembled a bone matrix in terms of morphology, collagen organization, and immunoreactivity. Conclusions The results indicate that DAMT and BIs formed in the canal space are distinct from each other, one exhibiting a unique mineralized tissue and the other a bone-like tissue.

Achievable Convergence Angle and the Effect of Preparation Design on the Clinical Outcome of Full Veneer Crowns in Dogs

It is widely accepted that the convergence angle of a full veneer crown preparation should be as close to parallel as possible to attain adequate retention/resistance. The shape of the dog's canine tooth limits the veterinary dentists' ability to achieve the recommended convergence angle. However, the clinically achievable convergence angle of the canine tooth in dogs has not been evaluated. In addition, the convergence angle and other physical properties of a preparation, such as height and base diameter, have been shown to affect the retention/resistance of full veneer crowns, in vitro. This effect has not been evaluated clinically in the dog. Physical properties of 32 stone dies from full veneer crowns of canine teeth were studied to evaluate the clinically achievable convergence angle and the potential effect physical properties of the preparation had on the clinical outcome of the restoration. The clinically achievable convergence angle was much higher than the current recommendation. There was an association, albeit not statistically significant, between physical properties of a preparation (convergence angle, height, base diameter) and the clinical outcome of the restoration.

Characterization of Dental Pulp Stem Cells Isolated from Canine Premolars

Introduction Dogs are commonly used animal models for regenerative endodontics research. Although several studies have used stem cells isolated from dog teeth to investigate the dentin/pulp regeneration in vivo, less attention has been paid for the characterization of these cells. Therefore, this study aimed to characterize the dental pulp stem cells isolated from dog teeth (cDPSCs) in order to further define the dog as an animal model for regenerative endodontics. Methods Stem cells were isolated from freshly extracted premolars of 10-month-old Beagles. The isolated cells were investigated for their stem cell properties by analysis of their clonogenic and growth characteristics; expression of mesenchymal stem cell markers; and evaluation of their osteo/odontogenic, adipogenic, and neurogenic potential. Results A colony formation assay showed the existence of a clonogenic cell population in cDPSCs isolated. The growth curves revealed a higher proliferation rate of cDPSCs compared with hBMMSCs. cDPSCs expressed mesenchymal stem cell markers STRO-1, CD146, and Nanog. However, they were negative for CD73, CD105, and CD45. cDPSCs were able to differentiate into odontoblast-like cells as shown by increased alkaline phosphatase activity, dentin sialoprotein expression, and formation of mineralized nodules. cDPSCs also showed the neurogenic and adipogenic differentiation potential at a lower level compared with those of hDPSCs and hBMMSCs. Conclusions The results of this study confirmed the stem cell properties of cDPSCs at a comparable level to those of hDPSCs and hBMMSCs. Overall, the data presented in this study provide evidence in supportive of using cDPSCs and dogs as an animal model in dental tissue engineering via stem cell–based approaches.

The influence of cone-beam computed tomography and periapical radiographic evaluation on the assessment of periapical bone destruction in dog's teeth

The aim of this study was to determine the influence of periapical radiographs, cone beam computed tomography (CBCT) sections, and cone beam volumetric data on the determination of periapical bone destruction in endodontically treated distal root canals of premolar canine teeth. Nontreated mesial roots were used as controls. Enterococcus faecalis strain (ATCC 29212) was inoculated into 30 root canals of 2 mongrel dogs to induce apical periodontitis. After 60 days, the root canals of the distal roots of the 11 mandibular and 4 maxillary premolars were endodontically treated (n = 15). The mesial root canals were used as controls (no treatment). The bone destruction was evaluated after 6 months by 5 evaluators using periapical radiographs and by CBCT (coronal and sagittal sections). After the experimental period, the area of the lesions in periapical radiographs and CBCT sections were measured in mm(2) using the ImageTool software. A single evaluator measured the volumetric data using the OsiriX software. The comparison between the diagnosis methods in treated root canals and controls was performed using parametric and nonparametric criteria. The Pearson correlation coefficient was computed between radiographic values and CBCT volumetric data in treated root canals and controls. The results showed the presence of chronic apical periodontitis in every inoculated tooth. After 6 months, periapical radiographs, coronal CBCT sections, and volumetric data showed lower bone destruction in endodontically treated teeth in comparison with the control group (P < .05). The 5 evaluators found no differences between the apical periodontitis area of treated teeth and controls when CBCT sagittal sections were used (P > .05). No correlation was found between x-ray and CBCT volumetric values in treated root canals. Although selected CBCT sagittal sections showed similar values of bone destruction in endodontically and nontreated root canals, volumetric CBCT data showed that periapical lesions of endodontically treated root canals had half of the volume of periapical lesions in nontreated root canals. No relationship could be found between the periapical values of bone destruction and volumetric data found in CBCT of treated rood canals.

Periodontal Tissue Engineering After Tooth Replantation

Blood-derived products, platelet-poor plasma (PPP) and platelet-rich plasma (PRP), constitute an approach in the enhancement of tissue healing. PRP has also been used as a scaffold for bone marrow stem cells in tissue engineering. This study evaluates the effect of PPP, calcium chloride-activated PRP (PRP/Ca), calcium chloride- and thrombin-activated PRP (PRP/Thr/Ca), and bone marrow mononuclear cells and PRP/Ca (BMMCs/PRP/Ca) on the healing of replanted dog teeth. After 30 minutes of extraction, teeth were replanted with 1) no material (control); 2) PPP; 3) PRP/Ca; 4) PRP/Thr/Ca; or 5) BMMCs/PRP/Ca. Histologic, histomorphometric, and immunohistochemical analysis was assessed 120 days after replantation. Data from histomorphometric analysis were analyzed statistically (analysis of variance, Tukey; P <0.05). Quantitative immunohistochemical analysis was analyzed by Kruskal-Wallis and Dunn post hoc test (P <0.05). Flow cytometry analysis showed 55.98% of CD34(+) and 32.67% of CD90/Thy-1 for BMMCs sample. BMMCs/PRP/Ca presented the largest areas of replacement resorption characterized by osseous ingrowth into cementum (P <0.05), with intense immunomarcation for tartrate-resistant acid phosphatase. The PRP/Ca group also showed areas of replacement resorption with significant immunomarcation for osteopontin. PRP/Thr/Ca presented no replacement resorption. PPP showed areas of inflammatory resorption, with immunomarcation for tartrate-resistant acid phosphatase. The results suggest that platelets activated with thrombin play an important role in the healing of tissues after tooth replantation. Additional studies are necessary to test other materials, because PRP/Ca did not present an appropriate scaffold for undifferentiated cells in the treatment of avulsed teeth.

Effect of (-)-epigallocatechin-3-gallate on maintaining the periodontal ligament cell viability of avulsed teeth: a preliminary study

PurposeAvulsed tooth can be completely recovered, if sound periodontal ligament (PDL) of tooth is maintained. Although a lot of storage solutions have been explored for the better storage of avulsed tooth, there is a shortcoming that the preservation time is much short. On the other hand, there has been studies that (-)-epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, which is related to the anti inflammatory, antioxygenic, and antibacterial effects, allows the successful preservations of tissues and cells. This study evaluated the effect of EGCG on avulsed-teeth preservation of Beagle dogs for a period of time.MethodsThe atraumatically extracted teeth of Beagle dogs were washed and preserved with 0/10/100 µM of EGCG at the time of immediate, period 1 (4 days in EGCG-contained media and additional 1 day in EGCG-free media), period 2 (8 days in EGCG-contained media and additional 2 days in EGCG-free media) and period 3 (12 days in EGCG-contained media and additional 2 days in EGCG-free media). Then, the cell viabilities of preserved teeth was calculated by dividing optical density (OD) of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with OD of eosin assay to eliminate the measurement errors caused by the different tissue volumes.ResultsFrom the results, the immediately analyzed group presented the highest cell viability, and the rate of living cells on teeth surface decreased dependent on the preservation period. However, the 100 µM of EGCG-treated group showed statistically significant positive cell activity than EGCG-free groups throughout preservation periods.ConclusionsOur findings showed that 100 µM EGCG could maintain PDL cell viability of extracted tooth. These results suggest that although EGCG could not be a perfect additive for tooth preservation, it is able to postpone the period of tooth storage. However, further in-depth studies are required for more plausible use of EGCG.

Histologic evaluation of root response to intrusion in mandibular teeth in beagle dogs

The purpose of this article was to histologically evaluate root resorption and repair after orthodontic intrusion with different force magnitudes and fixed anchorage. A randomized split-mouth repeated-measure design was used. Intrusive forces were applied for 98 days to the mandibular second, third, and fourth premolars of 8 mature beagle dogs. Two miniscrew implants were used as anchorage to apply constant intrusive forces of 50, 100, or 200 g per tooth. Demineralized sections of each tooth were stained and histologically studied for root resorption. Multilevel statistical procedures were used to evaluate the results. Root resorption was present in all teeth, independent of the force applied. Significant differences were found between root regions, with the apices and the interradicular regions the most affected and with dentin involvement at the furcation. There was cementum repair in 24.14% of the lacunae. Light constant intrusive forces between 50 and 200 g showed no significant differences in the amount of resorption produced. Resorption was more frequently seen at the level of the apices and the furcation. Orthodontically induced root resorption is not clinically significant after application of continuous intrusive forces between 50 and 200 g. Moreover, there is no relationship between root resorption, the position of posterior mandibular teeth in the arch, and the amount of intrusive force applied.

Root perforations treatment using mineral trioxide aggregate and Portland cements

Clinical, radiological and histological evaluation of root perforations treated with mineral trioxide aggregate (MTA) or Portland cements, and calcium sulfate barrier. One molar and 11 premolar teeth of a male mongrel dog received endodontic treatment and furcations were perforated with a high-speed round bur and treated with a calcium sulfate barrier. MTA, Portland cement type II (PCII) and type V (PCV), and white Portland cement (WPC) were used as obturation materials. The teeth were restored with composite resin and periapical radiographs were taken. The animal was euthanized 120 days post-surgery for treatment evaluation. Right lower first premolar (MTA), right lower third premolar (PCV), left lower second premolar (MTA), and right lower second premolar (WPC): clinically normal, slightly radio-transparent area on the furcation, little inflammatory infiltrate, and new-bone formation. Left lower third premolar (PCII), right upper first premolar (WPC), right upper third premolar (PCII), and left upper first molar (PCV): clinically normal, radiopaque area on the furcation, and new-bone formation. Right upper second premolar (MTA), left upper second premolar (WPC), left upper third premolar (PCII): presence of furcation lesion, large radiolucent area, and intense inflammatory infiltrate. All obturation materials used in this study induced new-bone formation.

Atypical face-scan patterns in children misinterpreting dogs facial expressions evidence from eye-tracking

Research shows that children get bitten at least twice as often as adults and children under 7 are at a significantly higher risk (Kahn et al, 2003; Kahn et al,...

Quantitative scintigraphic analysis of pulp revascularization in autotransplanted teeth in dogs

Objective: The purpose of this study was to evaluate the pulpal changes associated with autogenous single-rooted immature tooth transplantation in dogs, using either one, or two-stage surgical techniques. Methods: Teeth from 3 beagle dogs, 5 months old, were extracted and transplanted to mechanically prepared recipient sockets. Group (A), where the teeth were transplanted using a one-stage method to recipient beds prepared immediately before transplantation. Group (B), where the teeth were transplanted using a two-stage method in which the recipient beds were prepared and left to heal for 7 days before transplantation. Clinical examinations were done every week during 9 weeks. After 9 weeks, the animals were injected with 99mTechnetium hydroxylmethylene diphosphonate ( 99mTc-HMDP) and 3 h after injection, a whole body scintigraphic acquisition was performed. After scintigraphic acquisition the animals were euthanized and the teeth extracted and its radioactivity counted in a well counter calibrated to 99mTc. With the data obtained, the percentage of activity injected was calculated for each tooth. The data for each group of teeth were evaluated and analyzed using the Mann–Whitney test ( p = 0.05). Results: All the transplanted teeth in both groups survived. No statistically significant difference was found in the absorption of the 99mTc-HMDP, between the treatment groups ( p = 0.464) and between them and the control group (Group A vs. control p = 0.713 and Group B vs. control p = 0.157). Conclusions: This study demonstrated that there was no difference between the two surgical techniques in terms of the pulp revascularization in transplanted teeth.