Factors Influencing Vertical Radicular Fractures in Teeth Supported by Metallic Dental Core: A Scoping Review.

Purpose: The aim of this work is to conduct a literature review to highlight all the parameters involved in sub-prosthetic radicular fractures of teeth supported by metallic dental core. Materials and Methods: The following research was performed among published studies over the last 10 years in two PubMed/Medline and Scopus and supplemented by manual searching within the bibliographies. The search was restricted to publications in English and French. Results: Out of the 1464 articles initially identified, 18 studies met our inclusion criteria and were subsequently included in the literature review. These consisted of eight Finite Element Analysis Studies, two Retrospective Studies and one Randomized Controlled Trial. The results of this review show that radicular fractures are influenced by several variables, including predisposition, with maxillary premolars and mandibular molars being the most commonly affected teeth. Intracanal preparation can induce crack formation, leading to localized high stress concentrations. Increased ferrule height to 2 mm significantly enhances dental fracture resistance. Using high modulus of elasticity alloys results in nearly complete stress transmission to dentin due to their limited deformability and absorption capacity. The highest fracture resistance is achieved when posts are sealed using resin-modified glass-ionomer cement. Longer posts may be preferable to prevent vertical fractures. Additionally, occlusal factors, through repetitive stresses, contribute to crack propagation from surface defects, a phenomenon termed fatigue fracture. Conclusion: These findings have significant implications. Practitioners should be aware of the predisposition of certain teeth, the importance of preserving the ferrule effect, the choice of root post materials, post Cement Material and the role of occlusal forces in managing and preventing vertical root fractures.

La technologie CAD CAM: enquête auprès des techniciens dentaires de la ville de Rabat / CAD/CAM-Technology: A Survey among dental technicians in Rabat

La profession de prothésiste dentaire évolue et s'inscrit pleinement dans l'ère numérique. Cette révolution technologique s'est fait connaître sous le nom de CFAO dentaire (conception et fabrication Assistées par ordinateur), qui regroupe l'ensemble des étapes de numérisation et de conception informatique (CAO) et celles de fabrication à l'aide des machines-outils (FAO). La CFAO dentaire date de plus de 40 ans avec la thèse du Dr François Duret en 1973 intitulée « l'empreinte optique ¼, son développement a été, et reste encore, intimement dépendant des évolutions et des progrès de l'ingénierie et de l'informatique. Au sein du laboratoire de prothèse dentaire, la CFAO a connu une ascension fulgurante. En effet, cette technique a totalement modifié la pratique quotidienne des prothésistes dentaires en remplaçant certaines techniques traditionnelles. Cette nouvelle façon de concevoir les prothèses a permis ainsi aux laboratoires d'améliorer leurs travaux en termes de précision, de reproductibilité et de diversité des matériaux, tout cela en diminuant les erreurs en liaison avec le facteur humain. La CFAO a-elle véritablement remplacé les techniques conventionnelles dans la réalisation des prothèses dentaires ? Présente-t-elle de véritables avantages pour les prothésistes ? La CFAO a-t-elle un avenir au sein des futurs laboratoires de prothèse dentaire ? C'est dans ce sens que ce travail a été mené, afin d'étudier l'intégration et l'utilisation de la CFAO au laboratoire dentaire, à travers une enquête descriptive auprès des prothésistes dentaires exerçant dans la ville de Rabat, et de comprendre l'impact de cette technique sur l'exercice quotidien du prothésiste.

The dental technician profession is evolving and is fully integrated into the digital era. This technological revolution has become known under the name of dental CAD/CAM (computer-aided design and computer-aided manufacturing), which includes all the steps of digitization and computer design (CAD) and those of manufacturing with the help of machine tools (CAM). Dental CAD/CAM dates back more than 40 years with the thesis of Dr. François Duret in 1973 entitled "the optical impression", its development has been, and still is, intimately dependent on the evolution and progress of engineering and computer science. In the dental laboratory, CAD/CAM is on a meteoric rise. Indeed, this technique has completely changed the daily practice of dental technicians by replacing certain traditional techniques. This new way of designing prostheses has enabled laboratories to improve their work in terms of precision, reproducibility, and diversity of materials while reducing errors related to the human factor. Has CAD/CAM replaced conventional techniques in producing dental prostheses? Does it offer real advantages for dental technicians? Does CAD/CAM have a future in the dental laboratories of the future? In this sense, this work was conducted to study the integration and use of CAD/CAM in the dental laboratory through a descriptive survey of dental technicians practicing in the city of Rabat and to understand the impact of this technique on the daily practice of the prosthetist.

Acute and Subacute Toxicity Studies of the Aqueous Extract from Haloxylon scoparium Pomel (Hammada scoparia (Pomel)) by Oral Administration in Rodents.

MATERIALS AND METHODS: Acute toxicity test was performed on Swiss albino mice at a single oral dose of 1-10 g/kg for 14 consecutive days. General behavioral adverse effects, mortality, and latency of mortality were determined. In the subacute study, the Haloxylon scoparium Pomel extract was administered orally at doses of 500, 1000, and 2000 mg/kg daily for 30 days to Wistar rats. Body weight and selected biochemical and hematological parameters were determined at the end of the experiment. Sections of livers and kidneys were removed for histological studies. RESULTS: Acute toxicity study showed that the oral LD50 value of Haloxylon scoparium Pomel extract was 5000 mg/kg. The subacute toxicity study of Haloxylon scoparium Pomel extract at doses 500, 1000, and 2000 mg/kg did not produce any observable symptoms of toxicity and no significant variation in body weight, organ weights, food, and water consumption or mortality in all treated rats. However, the administration of the Haloxylon scoparium Pomel extract to rats at 500 mg/kg and 1000 mg/kg showed a significant decrease in platelets. Moreover, only at the highest dose (2000 mg/kg), the extract caused a significant increase in red blood cells and hemoglobin. Our results showed that subacute treatments with Haloxylon scoparium Pomel extract at doses of 1000 mg/kg and 2000 mg/kg significantly elevated alkaline phosphatase and triglycerides. Histological studies showed that the subacute treatments of rats with Haloxylon scoparium Pomel extracts, at the doses 1000 and 2000 mg/kg, induced some histopathological changes in the livers but a slight changing in kidneys. CONCLUSION: Our results indicated low acute toxicity of the aqueous extract of Haloxylon scoparium Pomel. Furthermore, daily oral administration of Haloxylon scoparium Pomel extract caused some damages to the livers of rats treated with high doses, expressed by an increase in some enzyme activities such as ALP. Regarding the renal function, we did not find remarkable toxicity in the subacute treatment with Haloxylon scoparium Pomel extracts at doses 1000 and 2000 mg/kg. However, further toxicity assessments should be done to ascertain the safety or the toxicity of this valuable plant species "Haloxylon scoparium pomel" in subchronic treatments.

Profile on medicinal plants used by the people of North Eastern Morocco: Toxicity concerns.

In the North Eastern region of Morocco, many people are interested in medicinal plants and their uses. However, the rationale for the utilization of medicinal plants has remained largely underestimated with little or no scientific data on plant safety. In this paper we attempt to describe and establish a detailed list of current knowledge in relation to the toxicity of these plants and to evaluate the scientific data concerning the harmful effects of the selected natural products. Our approach consists of collecting published data from literature in specialized journals, books and website related to the toxic plants. This research revealed that 89 plant species, retrieved from 287 plants used as medicine in the North-Eastern region of Morocco, are considered toxic or present some kind of toxicity. Our data determines 55 compounds isolated from the plants which are dominated by five groups of toxic compounds: alkaloids followed by glucosides, terpenoids, protides and phenolics. The present work discusses toxicity-related issues arising from the use of medicinal plants by local people. We conclude that the database considered in this study could serve as an important source of information on the toxicity of medicinal plants used by this society.

Substitution between Aristolochia and Bryonia genus in North-Eastern Morocco: toxicological implications.

ETHNOPHARMACOLOGICAL RELEVANCE: Although acknowledged as toxic herbs, Aristolochia species are still widely used worldwide. The aristolochic acids (AA) they contain can induce the so-called "aristolochic acid nephropathy", leading to renal fibrosis and upper urinary tract cancer. Traditional Moroccan medicine still often uses Aristolochia species under the vernacular name of Bereztem for the treatment of numerous ailments, notably cancer, diabetes or digestive tract disorders. As the botanical identity and renal toxicity of used species remain unexplored, the safety of patients may be threatened. MATERIAL AND METHODS: Ethnopharmacological data were collected from herbalists from the provinces of Oujda and Berkane, located in North-Eastern Morocco. Samples of Bereztem were collected at herbalist shops and checked for their content in AA using TLC and LC-MS methods. The toxicity of crude methanolic extracts of each herb was assessed on a HK-2 cell-based in vitro model by measurement of the cell survival to evaluate cytotoxicity and by assessment of renal-specific toxicity via (i) the evaluation of genes (E-cadherin and α-smooth muscle actin) expression by RT-qPCR; (ii) the quantities of ß-catenin and vimentin by immunofluorescence microscopy; (iii) the secretion of fibronectin; and (iv) the excretion of interleukin-6. RESULTS: The survey indicated that, among 42 herbalists visited, 33 were retailers of Bereztem, which was generally sold as a cancer treatment. Botanical investigations revealed that Aristolochia longa was frequently substituted by Bryonia dioica, which was associated with a higher cytotoxicity. Parameters specific to renal toxicity were also found to be enhanced, as compared to Aristolochia baetica and A. longa: down-regulation of ß-catenin and E-cadherin and up-regulation of vimentin and α-smooth muscle actin, and secretion of fibronectin and interleukin-6. CONCLUSION: In accordance with the Moroccan regulations, the use of so-called Aristolochia species should be discontinued. On one hand, the correctly identified aristolochia contain nephrotoxic aristolochic acids; on the other hand, aristolochia are massively substituted in North-Eastern Morocco and adulterated by a well-known toxic herb, B. dioica. Our data indicate that the bryony renal toxicity may be deleterious in shorter time periods than aristolochia. Reinforced on-site controls are needed to remind herbalists and harvesters that these herbs should be prohibited.