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At least 37 records · Page 2Linked to original sources
PubMed1996

Tooth root abscesses in New World camelids: 23 cases (1972-1994).

OBJECTIVE: To determine typical clinical and radiographic findings in a group of New World camelids with tooth root abscesses and to determine outcome after medical and surgical treatment. DESIGN: Retrospective case series. ANIMALS: 23 llamas and alpacas with radiographic and clinical evidence of tooth root abscesses. PROCEDURE: Disease history, signalment, physical and radiographic examination findings, bacteriologic culture results, treatment, and short-term and long-term outcome were retrieved from the medical records. RESULTS: Local swelling was the most common clinical abnormality in camelids with tooth root abscesses. Mandibular molars were affected most commonly, and bacteriologic culture of samples from lesions often revealed facultative anaerobic bacteria. Antibiotic treatment for at least 30 days, surgical extraction of the affected tooth, and a root canal procedure were used successfully to treat tooth root abscesses. CLINICAL IMPLICATIONS: Both surgical and medical treatment of tooth root abscesses may lead to successful resolution of clinical signs in New World camelids.

Animals↗
PubMed2001

Array-projection geometry and depth discrimination with Tuned-Aperture Computed Tomography for assessing the relationship between tooth roots and the inferior alveolar canal.

OBJECTIVES: The purpose of this study is to compare Tuned-Aperture Computed Tomography (TACT) image sets made with linear vertical, linear horizontal, conical, and x-shaped x-ray projection arrays with regard to observer accuracy in (1) measuring the distance from the apex of a tooth root to the middle of the inferior alveolar canal (IAC), (2) measuring the shortest distance from the surface of a tooth root to the surface of the IAC, and (3) determining whether the root is buccal or lingual to the IAC. The same relationships were also examined by means of pairs of images and the buccal object rule. STUDY DESIGN: Two artificial mandible sections with simulated IACs were fabricated. The same human mandibular premolar root was used in both models to prevent development of learning cues to differentiate between models. The models were imaged from both sides, resulting in 4 orientations. An optical bench was designed to precisely orient different beam projection arrays for production of TACT image sets and pairs of images for use with the buccal object rule. Twelve dentists participated as observers to independently assess the relationships between the tooth root and the IAC with regard to the 4 orientations. RESULTS: For measuring the distance from the tooth apex to the middle of the IAC, TACT image sets made from conical and x-shaped arrays proved significantly more accurate than TACT image sets made from linear vertical or linear horizontal projections or pairs of digital images used with the buccal object rule (P <.05). For measuring the shortest distance between the tooth surface and the IAC surface, TACT image sets made from linear vertical, conical, and x-shaped projection arrays were significantly more accurate than measurements made through use of the buccal object rule or TACT image sets made through use of a linear horizontal projection array (P <.05). The following percentages of mistakes were made in determining whether the tooth root was buccal or lingual to the IAC: buccal object rule (58%), linear horizontal array (31%), linear vertical array (2%), conical array (0%), and x-shaped array (0%). CONCLUSIONS: For TACT, images acquired with conical and x-shaped beam projection arrays are preferred to those acquired with linear arrays for assessing the relationship between tooth roots and the IAC. TACT was found to be significantly more accurate than standard application of the buccal object rule for the relationships investigated.

Alveolar Process↗
PubMed2001

An unusual staining of the tooth roots: a case report with histological and micro-analytical studies.

The discoloration of tooth roots is rare. We report here a 22-year-old Japanese woman with blackish-brown staining of the roots of the upper and lower third molars. Staining was found in the dentin and cementum. Electron probe X-ray microanalysis showed no significant difference in the composing elements between the stained tooth root and control tooth. Fluorescent bands coincided with staining in the dentin of the root and cementum along the incremental lines under confocal laser-scanning microscope.

Adult↗
PubMed1988

The relationship of the periodontal status to fluoride levels of alveolar bone and tooth roots.

The periodontal status and fluoride levels of alveolar bone and tooth roots were compared for subjects from a high (2.5 ppm F) and a low (less than 0.05 ppm F) fluoride area. The plaque index, gingival index, probing depth and loss of attachment were measured to determine the periodontal status. The fluoride levels were determined by the use of the fluoride ion-selective electrode. Both communities had high plaque and gingival indices. However, the mean pocket probing depths in both communities were less than 2.5 mm. No statistically significant differences could be found in the periodontal status between the 2 areas. The fluoride levels in bone and root were higher for subjects from the high fluoride area. No statistically significant difference could be demonstrated between the fluoride levels in alveolar bone and tooth roots for each area. It was found that the fluoride levels in bone and roots increased with increasing age, but to a lesser degree for subjects from the low fluoride area.

Adolescent↗
PubMed1999

Finite element analysis of anterior tooth root stresses developed during endodontic treatment.

Vertical tooth root fractures are diagnostically challenging, frustrating, and an increasingly common cause of failure of tooth restoration. These vertical root fractures have been associated with many causes, including the endodontic process itself. To investigate these endodontic causes, various phases of crown replacement for an anterior tooth were modeled using nonlinear, plane strain finite element (FE) analysis. Stresses developed during obturation, post positioning, crown placement, and masticatory and occlusal loading of the restored tooth were estimated using this analysis method. The minimum (compressive) principal stress was greatest during obturation of cones 1 and 2, and during mastication of the restored tooth. Although these stresses were significant (-150 to -280 MPa), they did not exceed the compressive strength of dentin. The maximum (tensile) principal stresses, 160 to 300 MPa, were also observed during obturation of cones 1 and 2. These peak stresses exceed the dentin tensile strength.

Crowns↗
PubMed2006

[Experimental study of the dental follicle's function in tooth root development].

OBJECTIVE: To study role of dental follicle in tooth root development. METHODS: Sixteen mandibular first molar dental germs from eight five-day postnatal Balb/c mice were divided into two groups randomly. Dental follicle of germs in one group was undetached and that of another group was removed. Subsequently, each of the germs was separately transplanted to back-muscles of adult nude mice. At seventh and fourteenth day after transplanting, the germs were collected, fixed, demineralized, dehydrated, and embedded in wax in sequence. Serial sections of 5 microm thick were made following the routine methods, stained with haematoxylin-eosin dying solution, and observed under a light microscope. RESULTS: All implantations were located in the back-muscles with abundant capillary vasculature. Under microscope, although all tooth germs could further develop after grafting, tooth germs without dental follicle developed slowly with small size and low calcification compared to those with dental follicle. Although position of Hertwig's epithelial root sheath of all germs seemed no changing, roots of the group with dental follicle could further develop and the roots develop toward the apical direction; this tendency couldn't be seen in the germs of another group. Inflammatory cells could be seen in and out of the pulp cavity of the two groups at 7th day after grafting, while no obvious inflammatory cell was observed at 14th day after grafting. CONCLUSION: Dental follicle play an important role in tooth root development. It probably can lead tooth root to develop in normal direction.

Animals↗
PubMed1976

Polymer-ceramic composite for tooth-root implant.

A new polymer-ceramic composite suitable for tooth-root implants has been developed in this study. This material exhibited the desirable combination of good mechanical properties, controlled porosity, and ease of processing. A thermal processing technique was utilized to polymerize acrylic acid (AA) in the presence of either 0.3 or 0.05 mu alumina particles. Porosity and pore size distribution were influenced by the alumina particle size and the processing technique. For a 50 vol % AA solution, the composite had an average compressive strength of 18,000 psi and 38% porosity when 0.3 mu filler particles were used. In comparison, the 0.05 mu alumina-filled composite had an average compressive strength of 28,000 psi with a 15% porosity. Data on the physical and structural characteristics of the composite are presented in this study. Based on these results, the composite material shows good potential for use in tooth-root implants as well as other orthopedic implant applications.

Absorption↗
PubMed1996

Wound healing and revascularization: a histologic observation of experimental tooth root fracture.

We used dogs as an animal model to generate tooth root fracture and to observe the wound-healing process of the fracture. Histologic examination of the specimens revealed that the early reaction of the wound healing was infiltration of inflammatory cells particularly at the coronal part of the fracture, whereas less inflammation but more abundant collagen fibers were seen at the apical part of the fracture (15 and 30 days). Inflammation lasted for more than 90 days and then subsided. At day 180, bone tissue healing was observed. Revascularization of the pulp tissues reached a high level at the same stage that bone healing took place. Our data suggest that in tooth root fracture, the regeneration of blood vessels is important in the wound-healing process and the revascularization is synchronized with the fracture wound healing. In this animal model the complete hard tissue healing could take as long as 6 months.

Animals↗
PubMed1990

A computer-aided image analysis system for area measurement of tooth root surfaces.

The characteristics of a computer-aided Image Analysis System (IAS) to conduct linear and area measurements on tooth root surfaces were investigated. The borders of the features to be measured were extracted from a digitized video image by histogram-based thresholding and binarization. The lengths and square areas were expressed in the number of pixels. The reference-length and area of one pixel were obtained through measurement of the diameter of a metal ball of known diameter in the same digital image. The validity of the IAS was tested using radiographs of teeth containing round metal restorations of known diameter and area. The accuracy of the length measurements ranged from -2.0 to 2.1%, whereas the accuracy of area measurement was between -5.3 and 0.8%. The precision of the IAS to identify the borders of a tooth root surface and to reproducibly calculate its area, expressed in a coefficient of variation, ranges from 0.49 to 4.11%. The results indicate that imaging techniques can be applied to obtain very accurate measurements of tooth root surfaces.

Dental Enamel↗
PubMed2003

Essential role for NFI-C/CTF transcription-replication factor in tooth root development.

The mammalian tooth forms by a series of reciprocal epithelial-mesenchymal interactions. Although several signaling pathways and transcription factors have been implicated in regulating molar crown development, relatively little is known about the regulation of root development. Four genes encoding nuclear factor I (NFI) transcription-replication proteins are present in the mouse genome: Nfia, Nfib, Nfic, and NFIX: In order to elucidate its physiological role(s), we disrupted the Nfic gene in mice. Heterozygous animals appear normal, whereas Nfic(-/-) mice have unique tooth pathologies: molars lacking roots, thin and brittle mandibular incisors, and weakened abnormal maxillary incisors. Feeding in Nfic(-/-) mice is impaired, resulting in severe runting and premature death of mice reared on standard laboratory chow. However, a soft-dough diet mitigates the feeding impairment and maintains viability. Although Nfic is expressed in many organ systems, including the developing tooth, the tooth root development defects were the prominent phenotype. Indeed, molar crown development is normal, and well-nourished Nfic(-/-) animals are fertile and can live as long as their wild-type littermates. The Nfic mutation is the first mutation described that affects primarily tooth root formation and should greatly aid our understanding of postnatal tooth development.

Alveolar Process↗
PubMed2000

Distribution of interglobular dentine in human tooth roots.

The present study was designed to examine the distribution of interglobular dentine in human tooth roots. The material comprised 17 teeth, of which 3 were premolars extracted for orthodontic reasons from children 10-12 years of age and the other teeth (4 incisors, 3 canines and 7 molars) were extracted for periodontitis from individuals aged 32-63 years. All teeth were free of caries and cervical dentine defects. Ground sections of the teeth cut longitudinally were stained with basic fuchsin and observed by fluorescence and confocal microscopy as well as transmitted light microscopy. Basic fuchsin stained the dentinal tubules, interglobular dentine and the granular layer of Tomes. These structures appeared intense blue to faint violet with transmitted light microscopy, whereas their staining displayed intense fluorescence with fluorescence microscopy. Therefore, the interglobular dentine could be detected more sensitively with fluorescence and confocal microscopy than with transmitted light microscopy. Typical interglobular dentine was present in coronal dentine in most of the teeth. In the radicular dentin, position and size of the interglobular dentine was different among the teeth examined. Most of the teeth had the interglobular dentine in the cervical part of the roots (type A). Two premolars displayed the interglobular dentine in the coronal half of the root (type B). The types A and B contained large interglobular areas. A small amount of interglobular dentine was restricted to the apical half of the roots of two canines and one molar (type C). In contrast to types A and B which were seen at both labial or buccal and lingual sides of roots, the interglobular dentine of type C was seen only at one side, labial or lingual. Some of the tooth roots did not show any interglobular dentine (type D). Most of the incisors, canines and premolar were types A, B, and C, respectively, and the molars were mixed types A, C, and D. These results suggest that the factors affecting dentinogenesis during root formation are unique for each tooth.

Adult↗
PubMed2005

Fracture strength of tooth roots following canal preparation by hand and rotary instrumentation.

The study aimed to determine fracture loads in tooth roots after canal preparation using different techniques. Mesiobuccal roots of 39 extracted mandibular molars were used. Three groups each of 13 roots were prepared by stainless steel hand files (K-files), and two rotary nickel-titanium techniques (Lightspeed and Greater Taper files). After obturation, a vertical load was applied by means of a spreader inserted into the canal until fracture occurred. The mean fracture load was 10.2 +/- 4.4 kg for K-files, 15.7 +/- 9.1 kg for Lightspeed and 13.2 +/- 6.1 kg for Greater Taper files, but differences were not statistically significant (p > 0.05). Most fracture lines were incomplete fractures on the buccal surface, followed by proximal and compound fractures. Greater apical enlargement (Lightspeed) or increased canal taper (Greater Taper files) did not increase fracture susceptibility of tooth roots.

Analysis of Variance↗
PubMed1990

An immediate tooth root replacement: an implant cylinder and synthetic bone combination.

Tooth extractions in 22 cases were treated immediately with the simultaneous placement of a cylinder implant and injection of particulate synthetic bone around the neck of the implant and into the extraction socket surrounding the cylinder. Preliminary results indicate a success rate of 94.1% in those implant/synthetic bone combinations placed in function. The utilization of synthetic bone in combination with an implant creates the possibility of an immediate tooth root replacement. Besides replacing a "lost part" of the jaw immediately, this practice prevents the normal 40% to 60% bone loss that occurs in the two years post-extraction and improves both function and aesthetics for the patient. The synthetic bone, HTR Polymer, was used in combination with Steri-Oss cylinders.

Alveolar Bone Loss↗
PubMedDate not supplied

[Radiographs and tooth roots in maxillary sinus].

Roentgenographic observations in 19 cases of tooth roots displacement to the maxillary sinus using 4 technics of periapical, topographic, Waters and panoramic projection. It was indicated that, 1). Left maxillary first molar root was forced into the antrum more frequently than the roots of other teeth. 2). Roots were displaced into sinus more frequently in males than females. 3). To identify the root, panoramic and topographic were helpful projection. Waters projection was of little or no value, for the root fragment. However it is useful in that it may provide indirect confirmatory evidence of an antral perforation and reveals the presence of sinus infection.

Female↗
PubMed1999

Ultrastructural changes of the tooth root surface by Nd:YAG laser irradiation followed by citric acid and tetracycline.

The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been used for treatment of dentinal hypersensitivity, eradicating periodontal pathogens, and facilitating calculus removal. However, Nd:YAG laser irradiation exerts potentially harmful effects on the tooth root surface. The purpose of this study was to examine the ultrastructural changes of the tooth root surface caused by Nd:YAG laser irradiation, and to determine whether chemical and mechanical preparations can correct these ultrastructural changes. Eighteen tooth specimens (3 x 3 x 0.5 mm) with healthy root surfaces were prepared and irradiated with an Nd:YAG laser at various power densities. Root surfaces were irradiated at 100 mJ at 20 pulses per second (pps) for 2 seconds followed by the application of citric acid (pH 1.2) or tetracycline solution (100 mg/mL) for 3 and 5 minutes, respectively, or ultrasonic scaling for 5 strokes of 3 seconds per stroke. As observed with low-vacuum scanning electron microscopy, (Wet-SEM), Nd:YAG laser irradiation at 70 to 100 mJ, 20 pps for 2 seconds caused surface cratering, areas of porosity, pitting, fissures, and lava-like structures in an area 140 to 280 microns in diameter. Irradiation of 50 mJ, 20 pps for 2 seconds, led to only mild surface charring. No evidence of morphologic changes was found when root surfaces were irradiated with the Nd:YAG laser at 20 mJ, 20 pps for 2 seconds or at 50 mJ, 10 pps for 8 seconds. The laser-induced lava-like structures were partially detached by citric acid (pH 1.2) etching and ultrasonic scaling, but not by tetracycline (100 mg/mL). These results indicate that chemical and mechanical preparations can be used effectively in conjunction with Nd:YAG laser irradiation for root surface preparation during both nonsurgical and surgical periodontal treatments.

Anti-Bacterial Agents↗