Comparison of hand-instrumented, heated gutta-percha and engine-driven, cold gutta-percha endodontic techniques

An in vitro study compared two gutta-percha obturation techniques of the mandibular first molar in dogs. The mandibular first molars were instrumented and obturated using either K-files and the SuccessFil vertical compaction technique or rotary instruments and the Simplifill/guttapercha master cone technique. Instrumentation and obturation times were recorded for each tooth. Radiographs were used for evaluation of overall appearance of the final fill. A modified apical dye leakage technique was used to evaluate the ability of each method to provide an adequate barrier to apical leakage. The endodontic technique utilizing rotary instruments and Simplifill/gutta-percha master cone required less time and provided a better radiographic appearance to the endodontic fill. In addition, there was no apical dye leakage associated with this technique compared with a 44% leakage incidence in teeth treated with K-file instrumentation and SuccessFil.     

Comparison of two heated gutta percha and sealer obturation techniques in canine teeth of dogs

The overall endodontic fill and apical seal achieved using two different obturation methods were compared. Twenty-six adult dog canine teeth were instrumented and obturated using either a warm vertical or heated lateral technique. Zinc oxide-eugenol sealer was applied by paper point in the warm vertical technique and by syringe injection in the heated lateral technique. The cadaver jaws were warmed to 35-37 degrees C (95-98.6 degrees F) during obturation using a circulating warm water bath. Obturation times were recorded and ventrodorsal, lateral, and oblique dental radiographs were taken of all teeth for comparison. Twenty-two of the canine teeth were extracted and an apical dye study was performed using a clearing technique. Apical dye leakage was linearly measured to evaluate the furthest ink penetration into the root canal. Although radiographically the heated lateral method appeared to have a better endodontic fill, there was significantly greater apical dye leakage in teeth obturated with that combination of sealer and gutta percha. There was also extrusion of sealer and root fracture associated with the heated lateral technique. The method of sealer application was different for each technique; this variable should be taken into consideration when interpreting our results, which suggest that the warm vertical compaction technique may provide a better apical seal in canine teeth of dogs in a shorter period of time, with fewer obturation complications when compared to the heated lateral technique.     

Comparison of cold GP/sealer and resin bonded obturation techniques in canine teeth in dogs

An in vitro study compared two obturation materials in the canine teeth in dogs. The teeth were instrumented with rotary instruments and obturated with either gutta percha and a sealer or resin-based materials, utilizing the gutta percha apical plug/master cone technique. Radiographs were used for evaluation of the overall appearance of the finalfill. A modified apical dye leakage method was used to evaluate the ability of each material to provide an adequate barrier to apical leakage. When comparing the two obturation materials, the differences in the radiographic appearance scores and the apical dye leakage test results were not statistically significant. The rate of apical leakage is comparable to other obturation methods that have been reported. The use of a rotary system in conjunction with the gutta percha apical plug/master cone technique is valid for the endodontic treatment of indicated teeth.     

Root surface temperature rise of mandibular first molar during root canal filling with high-temperature thermoplasticized Gutta-Percha in the dog

This in vitro study evaluated the temperature rise on the outer root surface of the mandibular first molar following root canal filling using the high-temperature, thermoplasticized, Gutta-Percha technique (HTTG) (BeeFill) in the dog. Twelve extracted dog mandibular first molars were used. After root canal preparation, the teeth were filled with thermoplasticized Gutta-Percha and root canal sealer. Temperature changes on the vestibular surfaces of the mesial and distal roots of mandibular first molars were measured using a thermal imaging camera. The results of this in vitro study showed that using HTTG to fill mandibular first molars in dogs produces a safe temperature rise on the root surface and, therefore, should not damage the periodontal ligament and/or surrounding tissues.     

Morphologic features of the root canal system of the maxillary fourth premolar and the mandibular first molar in dogs

Root canal morphology was evaluated in 72 maxillary fourth premolar and 59 mandibular first molar teeth. An apical delta was present in all roots (n = 334). The apical delta represented approximately 12-18% of the total root length for all roots. Non-apical ramifications from the main canal were observed in 25.1% of roots. Secondary canal(s) were present in 20.6% of roots, while lateral canal(s) were present in 6.9% of roots. The distal root of the maxillary fourth premolar had the highest incidence (47.2%) of non-apical ramifications. Overall, 68.0 and 20.4% of maxillary fourth premolar and mandibular first molar teeth had non-apical ramifications, respectively. The prevalence and location of non-apical ramifications may influence clinical decision making when performing endodontic therapy.     

Dens invaginatus of the mandibular first molars in a dog

A 6-year-old dog was presented for draining tracts associated with both mandibular first molar teeth. Radiographs of the affected teeth showed periapical bone lysis. Surgical tooth extractions were performed and the tooth segments were submitted for histopathologic examination. Microscopic evaluation of the teeth showed in folding of the enamel and dentin consistent with a diagnosis of dens invaginatus. Examination performed 13-months following the extraction procedures indicated uncomplicated healing at the extraction sites and no other visible evidence of endodontic disease.     

In vitro comparison of three materials as apical sealants of equine premolar and molar teeth

REASONS FOR PERFORMING STUDY: Surgical endodontic therapy is a conservative dental technique used in horses with some degree of clinical success. Failure of this procedure can partially be explained by inadequate sealing of the root apices with resultant microleakage in the periapical area. OBJECTIVES: To assess and compare in vitro sealing ability of 3 different dental restorative materials used as apical sealants during equine surgical endodontics. METHODS: Thirty extracted equine cheek teeth were divided randomly into 3 groups and subjected to apicoectomy and apical sealing using 3 materials: reinforced zinc oxide-eugenol cement; intermediate restorative material (IRM); a resin-modified glass ionomer; and amalgam. After apical sealing, the teeth were submerged in a solution of Procion Brilliant Cresyl Blue stain for a period of 7 days. The teeth were then washed, embedded in resin, sectioned and assessed microscopically for dye leakage around the apical restorations. RESULTS: Although the materials proved effective as apical sealants, some dye leakage was encountered in all 3 groups with no statistical difference (P = 0.114). CONCLUSIONS AND POTENTIAL RELEVANCE: IRM, a resin-modified glass ionomer and amalgam all showed comparative features as apical sealants when used in vitro in equine teeth. IRM is currently regarded as the superior material in clinical situations due to its ease of handling and lesser sensitivity to environmental moisture during placement compared to the other 2 materials.     

Timing of apical closure of the maxillary canine and mandibular first molar teeth of cats

Stage of apical closure was determined by radiographing the jaws of 15 cats at intervals from 5-11 months of age. The apices of the left mandibular first molar tooth were closed in all 15 cats by seven months of age and the apices of the left maxillary canine teeth were all closed by 11 months of age. The implications of the age of closure on endodontic pathology and treatment are discussed.     

Dental implant replacement of the mandibular first molar tooth in a dog

A new dental implant system was used to replace the mandibular right first molar tooth in an eleven-month-old male/intact, utility trained German shepherd dog. The permanent mandibular right first molar tooth had been extracted as treatment for an extensive carious lesion when the dog was 9-months of age. There were no complications associated with placement of the dental implant. However, peri-implant osteomyelitis occurred secondary to a traumatic oral wound 6-months following implant placement. The 17-month post-operative examination indicated that the implant system used in this case could be maintained in a working dog that uses extreme bite forces. However, periodontal inflammation and vertical bone loss exposing the implant fixtures were noted during oral examination. Further clinical applications are required to determine if the periodontal inflammation and vertical bone loss noted in this case were complications associated with the implant, maturity of bone at the time of implant fixture placement, general biting/chewing forces placed on carnassial teeth, or the oral trauma that occurred 6-months following implant placement.     

Treatment of maxillary cheek teeth apical infection caused by patent infundibula in six horses (2007–2013)

Six young horses presented with clinical signs of maxillary cheek teeth apical infection (bilateral in 2 horses) that included the presence of rostral maxillary swellings with discharging sinus tracts and were unexpectedly found to have no evidence of endodontic infection in 7 affected teeth. The apical infection of these teeth was attributed to infundibular dysplasia that allowed inoculation of the periapical tissue with contaminated oral contents. Treatment was by debridement and obturation of affected infundibula from their occlusal aspect using techniques normally used for endodontic therapy. Five out of 6 cases showed resolution of clinical signs over a mean follow‐up period of 19 months (range 6–48 months). These cases demonstrate that patency of the infundibular apex is a potential cause of cheek teeth apical infection in young horses, which can be successfully treated by debridement and subsequent infundibular restoration.     

Furcation canals of the maxillary fourth premolar and the mandibular first molar teeth in cats

The furcation region morphology was evaluated in 103 mature feline carnassial teeth (54 maxillary fourth premolar and 49 mandibular first molar teeth). Patent furcation canals were present in 27.2% of teeth. No significant difference (p = 0.88) in distribution of this anatomical variation was found between maxillary fourth premolar and mandibular first molar teeth. The mean width of these furcation canals was 104.0 microns with two-thirds of the canals having a buccal orientation. The presence of furcation canals could be a factor in the etiopathogenesis of feline dental resorptive lesions, as well as a characteristic to be considered in the diagnosis, prognosis, and treatment of endodontic or periodontic-endodontic lesions in cat teeth.     

Erupted bilateral compound odontomas in a dog

A six-month-old, male Black Russian terrier dog was presented for oral masses on the distolingual aspect of the mandibular left and right first molar teeth. Intraoral dental radiographs showed periodontal support of the small teeth (denticles). Oral and radiographic examinations of the remaining teeth indicated no other dental abnormalities. The denticles had histomorphologic features of small teeth including normal appearing crown and root structures. Clinical and histopathologic examinations resulted in a diagnosis of bilateral compound odontomas with completely erupted denticles. Treatment consisted of extraction of all denticles and extensive curettage. The dog had uncomplicated wound healing with no signs of recurrence based on oral examination performed 15-months postoperatively.     

Treatment of mandibular first molar teeth with endodontic-periodontal lesions in a dog

A two-year-old spayed/female Miniature Pinscher was treated for mobility of the left and right mandibular first molar teeth. Periodontal probing and intraoral dental radiographs indicated severe periodontal attachment loss. It was determined that both teeth had endodontic-periodontal lesions based on restoration of periodontal attachment and partial resolution of radiolucent periapical lesions following treatment which emphasized endodontic therapy.     

Hemangiomatosis associated with osteolysis of the mandible in a dog resembling Gorham-Stout disease in humans

A 6-month-old female German Shepherd Dog died as a result of profuse oral bleeding. At postmortem examination, the oral cavity showed visible roots of the right mandibular fourth premolar and first molar teeth and, in addition, they were very mobile and compressible. Radiographs showed a generalized radiolucency in the body of the right mandible, with evidence of resorption of the affected alveolar bone. Histologically, the lesion of the right mandible was characterized by the lysis of bony structures and a non-malignant proliferation of blood-filled vascular spaces lined by a single layer of well-differentiated endothelial cells. The clinical, radiographic, and histologic presentation of this dog is consistent with that associated with Gorham-Stout disease, a rare bone disorder in humans.     

Endodontic Instruments for Root Canal Therapy

This article on endodontic instrumentation includes endodontic instruments and techniques of root-canal preparation of teeth in veterinary patients. Familiarity with instruments covered in this article and with advances in veterinary endodontics has become necessary for the veterinary dental practitioner who wishes to practice dentistry using current techniques. Veterinary endodontic techniques that help to retain the teeth longer are increasing in demand as an option to extracting damaged teeth. Endodontic treatment involves removal of the irreversibly damaged pulp, followed by cleaning and shaping of the root canal space using endodontic instruments and subsequent filling, or obturation, with a semisolid material and a sealer.     

Observations of the periodontal ligament and cementum in cats with dental resorptive lesions

The etiology of feline dental resorptive lesions is unknown, but some evidence suggests that interactions between components of the periodontium may be initiating factors in the development of these lesions. In the present study, 22 clinically normal teeth were harvested from 7 cats. The teeth and periodontium were radiographed and examined histologically. In addition, 14 of the 22 teeth were examined histometrically. Two teeth were histologically normal with an open apical foramen and two were normal with a closed apical foramen. Histological evidence of periodontal ligament degeneration without cementum resorption was observed in 8 teeth, and varying degrees of cementum resorption were observed in 10 teeth. Mandibular molar and premolar teeth had distal drift, and mandibular canine teeth had mesial drift. Alterations in the periodontal ligament may represent a preclinical stage of dental resorption.     

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.     

Tooth resorption in the Swedish Eurasion lynx (Lynx lynx)

The etiology of tooth resorption in the domestic cat remains unknown. The high prevalence and progressive nature of the disease complicates defining healthy control groups. In order to evaluate the possible influence of various life style changes on the prevalence of tooth resorption, healthy control groups are a prerequisite. This paper presents a prevalence study for tooth resorption in a free-ranging wild felidae population. Skulls from 46 free-ranging Eurasian lynx (Lynx lynx) were examined. The age of the animals had previously been estimated based on cementum annuli in the maxillary right canine tooth. The dental examination included both dental probing and radiographic imaging. Complicated fractures of the canine teeth were found in 9/46 (19.5%) skulls. In one fractured canine, apical root resorption and periapical lucency was detected. The root resorption was attributed to inflammatory resorption as a consequence of the initial dental trauma and necrotic pulp. No signs of tooth resorption were found in the remaining teeth. Supernumerary roots were detected in 18/46 skulls (39.1 %). Supernumerary "peg" teeth caudal to the mandibular first molar tooth were detected in 6/46 (13.0%) skulls. Although further studies on dental ultra-structure are needed, the Swedish Eurasian lynx may, in the future, be useful as a healthy comparative model for studies on the etiopathogenesis of tooth resorption in the domestic cat.     

Mandible and mandibular first molar tooth measurements in dogs: relationship of radiographic height to body weight

Height measurements of the mandible and the mandibular first molar tooth were obtained from 234 dogs. Statistical analysis was performed to determine possible associations between these measurements and body weight, sex, age, and body condition. There was a statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and body weight (p < 0.0001) in all body weight groups. Small dogs had proportionally larger mandibular first molar teeth relative to mandibular height compared with larger dogs. This relationship may contribute to an increased susceptibility in small dogs for periodontitis and subsequent tooth loss. There was no statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and other parameters evaluated in this study.