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PubMedDate not supplied

[The role of sensory nerves in the development of inflammation of oral tissues].

Experimental stimulation and clinical procedures applied on the tooth crown cause vascular reactions in the dental pulp of cats and rats. These reactions depend on the activation of trigeminal afferent nerves and release of neuropeptides. A brief stimulation causes vasodilation, which is mainly mediated by calcitonin gene-related peptide (CGRP). A longer stimulation results in plasma extravasation which is mediated mainly by substance P (SP) and prostaglandins in the pulp. In adjacent oral tissues the mechanisms following stimulation or local irritation are more complex and other mediators are also involved. Nitric oxide (NO) which is instantly produced in the tissues is such a novel mediator. The chemosensitive nature of the nerves involved (capsaicin sensitive) may lead to their activation also by inflammatory mediators released in the tissues. Thus, sensory nerves may modulate the progress of inflammation. Since sensory nerves in oral tissues are often the first structures to be activated during clinical procedures, tissue reactions that occur can be assumed to be initiated and perpetuated by the sensory neuropeptides. Much work is now made to modulate the sensory nerveinduced cascade of events in oral tissues to find new treatment strategies.

Animals↗
PubMed1997

Reattachment of coronal fragments: operative considerations for the repair of anterior teeth.

The maxillary incisors occupy an extraordinary position in the dental arch. They set the aesthetic tone, and their influence on the overall well-being of the individual cannot be overemphasized. However, their eruptive pattern and dominance carries a significant risk for trauma, particularly in childhood. More than half of all traumatic dental injuries involve the central incisors. In the past, fractured teeth were either extracted, trimmed and leveled, or restored with cast restorations. The learning objective of this article is to stimulate a shift in treatment strategy towards aesthetic reattachment of fractured segments. Indications and limitations for reattachment are outlined, including the primary and secondary restorative efforts. Innovative operative techniques that improve the aesthetic, biologic, and mechanical variables of the reattachment treatment option are presented.

Dental Bonding↗
PubMedDate not supplied

Dental trauma in schoolchildren six to twelve years of age.

The prevalence of dental injuries in Spanish children living in an urban area was studied in 4000 schoolchildren ages six to twelve years. A total of 227 children experienced dental injuries. Simple enamel fracture was the predominant injury (46.2 percent). Boys showed a higher prevalence than girls In the majority of cases (74.9 percent), the trauma affected one tooth only. The maxillary central incisor was the most frequently affected tooth (87.9 percent). The most common fracture site was the mesioincisal angle (40.6 percent) followed by distoincisal angle (27.3 percent). Twenty-four percent of the children with dental injuries had an overjet of more than 3 mm.

Child↗
PubMed1995

Single tooth, implant-stabilized crowns replacing anterior teeth: a clinical comparison of two systems.

Implant-supported single-tooth crowns are suitable alternative restorations to partial dentures and bridges. A number of systems have been developed to create a good aesthetic result without the display of the standard titanium abutment traditionally used in restorations with complete fixed prostheses supported by titanium endosseous implants. This paper reviews two such systems.

Adult↗
PubMed2004

Absence of apical resorption during orthodontic treatment on a tooth with a complicated crown fracture and root canal treatment: a case report.

Root resorption often occurs after tooth trauma and may also occur during orthodontic tooth movement. This has been attributed to bacteria and inflammation or a combination of both aetiologies. The literature suggests that root canal treatment performed on a traumatized tooth that will concurrently or subsequently undergo orthodontic tooth movement may forestall the resorptive process. This case report provides evidence for this prevention and discusses the hypothesis for the absence of resorption on root-treated teeth.

Adolescent↗
PubMed2003

Temperature and thermal stress analysis of a crowned maxillary second premolar tooth using three-dimensional finite element method.

The purpose of this study was to calculate the temperature and thermal stress distribution as a result of hot/cold liquid in the mouth. This numerical study was carried out using three-dimensional finite element models and the tooth model was crowned with Au-Pd alloy, Ni-Cr alloy and porcelain. In the first part of the study, temperature changes as a result of hot/cold liquid in the mouth were calculated. In the second part, the thermal stresses caused by temperature changes were obtained. The tooth was assumed isotropic, homogenous, elastic and unsymmetrical. The authors using fortran 77 prepared all calculation programs. The distribution of temperature and thermal stress were plotted for some critical points.

Bicuspid↗
PubMedDate not supplied

Metal ceramic crowns--a review of tooth preparation.

The metal ceramic crown has become the most popular extra-coronal restoration in the armamentarium of the dentist, certainly within the UK. It combines the aesthetic qualities of porcelain with the strength of cast metal. This review discusses a number of issues relating to these crowns, and considers the principles of tooth preparation and marginal fit. The physical requirements of tooth preparation are considered in terms of shoulder width, emergence profile, shoulder angle and effects on the pulp. It also considers the teaching of metal ceramic crown preparation, the failure of metal ceramic crowns and the influence that preparation quality has on these failures.

Crowns↗
PubMedDate not supplied

Differential diagnosis of pericoronal radiolucencies with and without radiopacities.

Pericoronal radiolucencies, by definition, surround the crown of a tooth. They are encountered not only in pediatric patients but also in adults of all ages. It is likely that all clinicians, at some time or another, will be confronted with a radiograph showing a pericoronal radiolucent lesion. The differential diagnosis of such lesions is reviewed.

Adult↗
PubMed1998

Oral manifestations of Ellis-van Creveld syndrome: report of two siblings with unusual dental anomalies.

Ellis-van Creveld syndrome (EvC), also called chondroectodermal dysplasia, is a rare occurrence inherited as an autosomal recessive disease. Despite the fact that oral manifestations play an important role in the diagnosis criteria for EvC, few detailed reports have been published in the dental literature. This articles presents two siblings with EvC, a boy aged 9 years and a girl aged 7 1/2 years, a product of unaffected first cousin parents. The patients manifests: chondrodysplasia of tubular bones resulting in disproportionate dwarfism, polydactyly and syndactyly of hands and feet, severe dystrophic nails, multiple broad labial frenula with abnormal attachments, congenital missing incisors, anomalous teeth, bilateral partial clefts of the alveolar bone, and malocclusion. Other features noted in either cases are: congenital heart defect, median notch of the upper lip, shovel-shaped incisors and taurodontism. Of the unusual dental findings observed in our patients are talon cusp, reduced crown size, supernumerary tooth, and early eruption of teeth. Because half of the cases with EvC have cardiac malformation, dental treatment must be performed under prophylactic antibiotic coverage. Dentists play an important role in early diagnosis and control of dental problem of this condition.

Anodontia↗
PubMed2005

Shading of ceramic crowns using digital tooth shade matching devices.

In the 1990s, there was great optimism due to the development of devices for measuring tooth shade. The frequently not so simple, visual determination of the shade of a tooth was to be done with the aid of a device which recognizes the shade and describes it accurately by reference to a color chart. However, the skepticism towards such devices was also great. It is known that the color effect frequently differs strongly when comparing a tooth from the shade guide with a metal ceramic crown, despite identical shade designation. Anyone who considers visual shade determination to be inadequate and places his hopes in digital shade matching devices will be disappointed. It is the shade-generating structures of the metal ceramic and frequently of the veneer layers that turn out to be too thin which, despite correct shade selection, cause a different color perception. Such problems have been reduced decisively with the development of fracture-proof hard porcelain caps (Vita In-Ceram) with optical characteristics similar to teeth. In addition, the Vita System 3D-Master tooth shade system developed in 1998 by Vita in cooperation with Dr. Hall from Australia, leads the practitioner to a better understanding of the primary tooth shade characteristics of "brightness (value)", "color intensity (chroma)" and "color (wave length of the visible light, hue)". These two innovations allow a more accurate estimate of the basic shade of a natural tooth (reference tooth) and the imitation in the laboratory of its natural, shade-generating structures. If digital shade measurement supplements the visual shade estimate, then a further improvement can be expected--especially in the recognition of the basic shade. Qualitative descriptions of subjective shade measurement of a natural tooth and of its imitation in the dental laboratory by ceramics can be found frequently in professional journals and publications. With digital tooth shade matching devices, which apart from the color code of the color chart also reproduce exact, colorimetric values, such work processes can be recorded quantitatively and objectively. Reports about this type of controlled shade determination and generation are found rarely in the literature, which is surprising in view of the large number of tooth shade matching devices and dental ceramic systems available. In the present paper, the influence of the individual ceramic layers on color perception is measured and described under standardized conditions. The creation of the basic shade as it results from the composition of the various ceramic layers is traced with a spectrophotometer. The Vita In-Ceram Alumina infiltration ceramic and the VitaVM7 veneer ceramic were selected as the ceramic system. MHT-SpectroShade and Vita Easyshade were used as shade matching devices.

Aluminum Oxide↗
PubMed1998

[The effect of retinoic acid on crown morphogenesis of mouse tooth germs in vitro].

OBJECTIVE: To study the effects of retinoic acid on crown morphogenesis of early tooth germs. METHODS: Mouse tooth organ culture model was used and the functions of different retinoic acid concentration on the first mandibular molar germs of 14-day old mouse embryo were examined. RESULTS: The first mandibular molar germ of 14-day old mouse was at the bud stage. After 6 days culture, tooth germs in culture medium (not containing retinoic acid) developed from bud stage to bell stage and formed normal cusps. The morphogenesis of tooth germs in medium containing 1 x 10(-7) mol/L retinoic acid was similar to molar germs in the medium without retinoic acid. When the concentration of retinoic acid increased to 1 x 10(-6) mol/L, the mouse tooth germs still developed from bud stage to bell stage, but normal cusps was not formed. CONCLUSION: The results suggest that high concentration of retinoic acid alter crown morphogenesis of tooth germs.

Animals↗