Analysis and Assessment of Pulp Vitality of 102 Intrinsically Stained Teeth in Dogs.

Our prospective study analyzed clinical, radiographic, and histological characteristics of 102 intrinsically stained teeth. Sixty-nine dogs ranging from one to fifteen years of age were included in this study. Little more than half of the intrinsically stained teeth had no evidence of coronal injury (53.9%, 55/102). We found that most intrinsically stained teeth were histologically nonvital (87.6%, 85/97) and approximately 2/3 of these (57.7%, 56/97) had no histological endodontic or periodontal inflammation at the time of evaluation. Radiographic evidence of endodontic disease was present in 57% (58/102) of the intrinsically stained teeth. Radiographic evidence of periodontal disease was present in 48% (49/102) of intrinsically stained teeth and 28% (29/102) had radiographic evidence of tooth resorption. 18.6% (19/102) of intrinsically stained teeth were radiographically normal. Evidence of pulp necrosis was common in these intrinsically stained teeth, while only occasional teeth (12.4%, 12/97) had histologically confirmed pulpitis. All teeth with radiographic evidence of periapical lucency had pulp necrosis. Based on our histological findings, the majority of intrinsically stained teeth 87.6% are truly nonvital.

Decision-Making and Management of Immature Permanent Teeth with Crown Fractures in Small Animals-A Review.

Immature permanent teeth with crown fractures present a unique challenge in human and animal patients. Immature permanent teeth have not yet developed completely, often presenting with thin dentin walls, incomplete apical formation, and increased crown-to-root ratios. Loss of pulp function at this stage has devastating long-term implications for these teeth. Ideally, attempts should be made to preserve pulp vitality in immature permanent teeth to allow for continued dental development. The range of treatment options for vital teeth includes odontoplasty with bonding and sealing +/- restoration, indirect pulp capping, and direct pulp capping/vital pulp therapy. These treatments have long been established in human and veterinary medicine, and cases have been reported in dogs and cats. Apexification using calcium hydroxide is a well-established treatment for nonvital immature teeth. The advent of mineral trioxide aggregate and other bioceramic materials for use in vital pulp therapy and apexification has reduced treatment sessions and improved outcomes. Recent developments in the field of regenerative endodontic therapy further expand treatment options and provide the possibility for continued development of a formerly nonvital tooth. Selecting the appropriate treatment based on the severity of tooth fracture and status of pulp vitality can avoid a lifetime of poor structure and function for the affected tooth. This article provides multiple step-by-step protocols for the management of immature permanent teeth with crown fractures in small animals.

BACTERIAL PROFILE OF NECROTIC PULPS IN CHEETAH (ACINONYX JUBATUS) CANINE TEETH.

The role of microbes and their antimicrobial susceptibilities in both acute and chronic infections of the dental pulp in humans has been well studied. Presently, no data are available on endodontic pathogens in cheetahs (Acinonyx jubatus). The aim of this study was to isolate and identify the bacteria found in the canine teeth of cheetahs, where the pulp was necrotic and exposed due to a complicated crown fracture. Thirty-six microbiologic samples were taken from root canals (RCs) of the canine teeth of 19 cheetahs: one pulp sample was taken from 10 cheetahs, four samples from 2 cheetahs, two samples from 3 cheetahs, and three samples from 4 cheetahs. Exposed pulps were cultured for aerobic and anaerobic bacteria; an additional screening with a 16S rRNA-specific polymerase chain reaction (PCR) was used for the last six samples. Antimicrobial susceptibility of isolates was determined by use of the Kirby-Bauer diffusion test. In total, 59 cultivable isolates belonging to 19 microbial species and 13 genera were recovered from the 36 RCs sampled. Only two samples yielded no cultivable bacteria. Thirty-two (54.49%) of the cultivable isolates were Gram positive and 27 (45.71%) were Gram negative. The maximum number of isolates cultivated from an individual RC was six. Facultative anaerobes (62.72%) were the most common bacteria of the RCs that yielded cultivable bacteria. Of the isolates, 28.81% were aerobic and 8.47% were strict anaerobes. The antimicrobials that showed the greatest efficacy in vitro against the different bacteria isolates were amikacin and gentamicin. The more common bacterial species isolated by PCR were anaerobes (60.8%), facultative anaerobes (30.2%), and aerobes (8.6%).

Consequences of crown shortening canine teeth in Greenland sled dogs.

OBJECTIVES: To evaluate the consequences of crown shortening, focusing on the prevalence of pulp exposure and periapical pathology in Greenland sled dogs that had had their canine crowns shortened at an early age. METHODS: Five cadaver heads and 54 sled dogs underwent an oral examination for dental fractures and pulp exposure of canines. All canines were radiographed and evaluated for periapical pathology. RESULTS: The prevalence of canine pulp exposure in 12 (5 heads and 7 dogs) crown shortened dogs was 91 · 7%, and 21 · 3% in 47 not-crown shortened dogs. A significant (P < 0 · 001) risk of pulp exposure of the canines in the crown shortened group compared to the not-crown shortened group was seen with a relative risk of 4 · 3 on a dog basis and a relative risk of 12 · 2 on a tooth basis. In dogs with pulp exposure of canines (n = 51) the prevalence of periapical pathology was 82 · 4%, but only 0 · 8% in dogs without pulp exposure (n = 133) resulting in a significant (relative risk, 109 · 5; P < 0 · 001) risk of periapical pathology in teeth with pulp exposure compared to teeth without pulp exposure. CLINICAL SIGNIFICANCE: The high risk of periapical pathology observed in teeth with pulp exposure confirms that these teeth should not be neglected in affected dogs.

Magnetic resonance imaging of pulp in normal and diseased equine cheek teeth.

A retrospective analysis of 619 upper and lower cheek teeth from 62 horses was performed. Based on clinical findings, as well as radiographic and magnetic resonance (MR) imaging findings, the teeth were classified into five groups. There were 20 teeth with abnormal MR imaging signals as well as clinical alterations and 599 healthy teeth. Using MR imaging, the appearance of pulp in diseased and disease-free teeth was compared, and the appearance of abnormal pulp was studied. Subsequently, the ability of MR imaging to diagnose pulpitis and pulp necrosis in teeth with normal external appearance was investigated. In horses with clinically verified dental disease, abnormal MR imaging findings were confirmed in the pulp of all affected teeth. An enlarged blurred pulp image with a lower signal intensity was observed only in clinically diseased teeth and was a reliable criterion for diagnosing dental disease on MR imaging. On the other hand, partial or complete absence of pulp in all MR imaging sequences was observed in both diseased and nondiseased teeth. These data demonstrate that pulp changes in equine cheek teeth can be evaluated using MR imaging.

Temperature changes in dental pulp associated with use of power grinding equipment on equine teeth.

OBJECTIVE: To quantify the temperature changes in the dental pulp associated with equine dental procedures using power grinding equipment. DESIGN: A matrix experimental design with replication on the same sample was followed to allow the following independent variables to be assessed: horse age (young or old), tooth type (premolar or molar), powered grinding instrument (rotating disc or die grinder), grinding time (15 or 20 seconds) and the presence or absence of water coolant. PROCEDURE: Sound premolar and molar teeth from a 6-year-old horse and a 15-year-old horse, which had been removed postmortem, were sectioned parallel to the occlusal plane to allow placement of a miniature thermocouple at the level of the dental pulp. The maximum temperature increase, the time taken to reach this maximum and the cooling time were measured (n=10 in each study). The teeth were placed in a vice and the instrument used on the tooth as per clinical situation. RESULTS: Significant differences were recorded for horse age (P < 0.001), instrument type (P < 0.001), grinding time (P < 0.001) and presence or absence of coolant (P < 0.001). There was no significant difference for tooth type. CONCLUSION: Thermal insult to the dental pulp from the use of power instruments poses a significant risk to the tooth. This risk can be reduced or eliminated by appropriate selection of treatment time and by the use of water irrigation as a coolant. The increased dentine thickness in older horses appears to mitigate against thermal injury from frictional heat.

In vitro study of heat production during power reduction of equine mandibular teeth.

OBJECTIVE: To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. DESIGN: In vitro study. SAMPLE POPULATION: 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. PROCEDURE: 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, and group-C2 (10) teeth were ground for 2 minutes with water for coolant. RESULTS: Mean temperature increase was 1.2 degrees C at the distal thermocouple and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C at the proximal thermocouple for group-C2 teeth. CONCLUSIONS AND CLINICAL RELEVANCE: In general, an increase of 5 degrees C in human teeth is considered the maximum increase before there is permanent damage to tooth pulp. In group-NC2 teeth, temperature increased above this limit by several degrees, whereas in group-C2 teeth, there was little or no temperature increase. Our results suggest that major reduction of equine teeth by use of power instruments causes thermal changes that may cause irreversible pulp damage unless water cooling is used.

Results of crown-height reduction and partial coronal pulpectomy in rhesus monkeys (Macaca mulatta).

BACKGROUND AND PURPOSE: In research facilities using non-human primates, crown-height reduction with partial coronal pulpectomy ("vital pulpotomy") is routinely performed on canine teeth of adult male monkeys to reduce self-trauma and the potential for injury to staff or cage-mates. Success of pulpotomy techniques in humans is reportedly 40 to 60%. Failure leads to chronic inflammation and pulp necrosis, which introduces variability in research animals, and may affect research results. The purpose of the study reported here was to determine failure rate of this procedure by evaluating clinical and radiographic findings at 3, 9, and 24 months after crown amputation and partial coronal pulpectomy of maxillary canines in adult male rhesus monkeys. METHODS: Forty-seven maxillary canine teeth from 24 adult male rhesus monkeys were treated by use of crown amputation and partial coronal pulpectomy, using standard dental technique. Follow-up clinical and radiographic examination was performed 3, 9, and 24 months after surgery. RESULTS: At three months after surgery, there was no clinical evidence of failure at any of the teeth. On the basis of radiographic findings, 2 of 47 teeth had failed and one was suspicious for early failure. At nine months, clinical evidence of failure was not apparent; radiographically, 5 of 44 teeth appeared to have failed and 3 others were suspect. Two years post-operatively, failure was clinically evident at two teeth, with radiographic evidence of failure in five teeth, and suspicion of early failure in an additional six of 41 teeth [corrected]. CONCLUSIONS: The failure rate of crown amputation and partial coronal pulpectomy of canine teeth in adult male rhesus monkeys is high, and the chronic inflammation associated with this is cause for concern.

Localized intrinsic staining of teeth due to pulpitis and pulp necrosis in dogs.

Dental charts and records of 71 dogs were received and 84 intact tooth crowns were noted to have been entirely discolored in shades of pink, purple, grey, or tan. Endodontic therapy was performed on 49 of these teeth allowing gross examination of the entire pulp. In exploratory pulpotomy was performed in 15 teeth prior to exodontic therapy in order to assess the integrity of the coronal pulp. Gross signs of partial or total pulp necrosis were present in 59 (92.2%) of these teeth. The pulp was not observed grossly in 20 teeth which received exodontic therapy. Overall, of the 84 teeth evaluated, 36 (42.9%) had no radiographic signs of endodontic disease. Gross or radiographic signs of endodontic disease were absent in only 2 (4.1%) discolored teeth receiving endodontic therapy. Based on the low incidence of vital, affected teeth in the dogs of this study, endodontic on exodontic therapy is recommended for discolored teeth.

Endodontic treatment including apexification in a chow chow with a necrotic immature mandibular canine tooth.

A necrotic immature mandibular, canine tooth in a two year-old, male, intact Chow Chow was endodontically treated. This tooth had an open apex, wide root canal, thin dentinal walls, and there was periapical bone resorption. An apexification procedure was used to induce apical closure by calcified tissue formation, with resolution of the periapical inflammation.

Use of a resin-ionomer in crown-root fracture repair of a canine tooth of a dog.

A resin-ionomer material was used to repair a longitudinal sub-crestal crown-root fracture of a maxillary canine tooth of a young dog. Infinity, the resin-ionomer used in this report, has been shown in human studies to be biocompatible with soft and osseous tissues, making it appropriate for use as a subgingival restorative material. The tooth was treated endodontically to achieve apexification, followed by conventional endodontic treatment, crown-root fracture repair, and preparation for placement of an Inceram crown.