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Objectives: This study aimed to evaluate the success of computer-aided design-computer-aided manufacturing (CAD-CAM) endocrown restorations of endodontically treated teeth (ETT) performed by supervised undergraduate students. The study also intended to identify possible factors that may lead to failures., Methods and Materials: This observational open cohort study was based on clinical data from endocrown restorations performed by residents and undergraduate students in their 4th, 5th, and 6th year from July 2011 to May 2018. The presence of a tooth with an endocrown on the arch was the main criteria used to calculate the survival rate of restored teeth. The quality of the remaining endocrowns was evaluated referring to the FDI criteria. The cases of failure were categorized into either favorable or unfavorable., Results: A total of 343 ETT were restored with endocrowns in 315 patients. Among them, 199 patients encompassing 225 endocrowns were followed during a 56 ± 26 month period. The survival rate of restored teeth was found to be 81.8%, the estimated Kaplan-Meier survival rate being 71.8% at 9 years. Among the 41 failed cases, 32 were favorable (debonding and/or ceramic fractures) and 9 were unfavorable., Conclusion: Endocrown restorations of posterior ETT using CAD-CAM technologies could be carried out by undergraduates with a low risk of failure. Teacher supervision could be reinforced, covering all steps of each endocrown procedure in order to avoid failures due to insufficient thickness or loss of retention., (©Operative Dentistry, 2021.)

Objectives: The frequent instability of mandibular removable complete dentures causes an alteration of mastication. An innovative therapeutic strategy involves placing four symphyseal mini implants. This study aimed at assessing the development of masticatory parameters and the impact on quality of life in subjects that underwent this procedure., Methods: Eleven edentulous subjects (mean age 72±11 years) with unstable mandibular complete dentures were followed-up before (T0) and two - three months after (T1) mini implant setting. Physiological parameters (number of cycles, duration of sequence and frequency of mastication) during the mastication of food models and the bolus median particle size (d50) of carrot were evaluated at each time. Quality of life was assessed at T0 and T1 using the Global Oral Health Assessment Index (GOHAI). Parametric tests were used to test relationships between mastication, quality of life variations and mini implant setting, and to compare each parameter mean value at times T0 and T1., Results: More subjects were able to chew carrot after setting the mini implants (8 subjects compared to 4 at T0). This improvement was accompanied by changes in kinematic parameters when chewing carrots, soft and hard model food, and by an improvement of their quality of life. However, the particle size values observed in the bolus remained higher than for normal dentate subjects (9.2±2.8mm)., Conclusions: These results indicated that the placement of mini implants as retentive elements for mandibular full dentures had a positive impact on patients' masticatory function and quality of life., Clinical Significance: The placement of mini implants has a positive impact on the masticatory function and oral health quality of life. The results suggest that this alternative procedure can be used as a treatment option for patients unable to receive conventional implants., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

For 20 years, on a worldwide scale, the prevalence of obesity has always progressed as well in child as in adult. Obesity is frequently associated with other pathologies: cardiovascular, oncologic, systemic (diabetes) or oral. In this situation, the follow-up of obesity and its co morbidity needs a multidisciplinary approach. Obesity and oral health pathologies have risk factors in common, particularly dietary one. Indeed, it is established that food affects oral health. In the same way, an unbalanced diet raises the risk of overweight or obesity. Thereby, owing to these inter relations, the World Health Organization advocates to insert oral health in the Program for Global Health. First, this study presents the factors of risks that obesity and oral health diseases have in common. After, the risks and the specificity of the care of obese patients are outlined. Consecutively, a program of prevention and education of oral health is proposed.

Objective: The aim of this study was to define the characteristics of muscular activity in complete denture wearers and in dentate subjects during mastication of model foods differing in hardness but similar in terms of rheologically properties., Material and Methods: The foodstuffs used in this study were laboratory-developed gumdrops demonstrating viscoelastic properties. The test foods cover a range of four hardness levels. The group of complete denture wearers included 15 subjects, while the control group included 9 subjects with normal dentition. Electromyograph (EMG) recordings were taken from the masseter and temporal muscles during mastication of the test foods. The results were evaluated by one-way and two-way ANOVA followed by means comparisons using a Student-Newman-Keuls post hoc test (alpha=0.05)., Results: Preparing the same food bolus for swallowing required a greater number of masticatory cycles and a longer duration of mastication for complete denture wearers than for dentate subjects. In addition, complete denture wearers failed to increase EMG activity per cycle in response to hardness of the food., Conclusion: Denture wearers experienced difficulties during mastication, as indicated by a decreased masticatory rate and the observed failure to increase EMG activity per cycle in response to increased food hardness. The increases in number of cycle and masticatory duration appear to be a response to this impaired masticatory function.

Backgrounds and Aims: The ability to evaluate masticatory function in people with neurological disabilities is important as this function is often compromised in these groups. However, current standard techniques are often impossible in such groups due to cognitive difficulties. This study is a validation of several variables read from standardised video recordings of mastication as indicators of masticatory function., Methods: Fifteen healthy, fully dentate male subjects were recorded using EMG and by video simultaneously. An evaluation was undertaken of the video parameters (i) to compare their validity against the electromyographic parameters, (ii) to test intra-rater and inter-rater reliability and (iii) to test the ability to discriminate between four model foods differing in hardness., Results: Masticatory time and the number of masticatory cycles counted on video were found to be valid and reliable indicators. In addition, the number of active chewing cycles performed with an open mouth and identification of the chewing side, were found to have reasonable validity and reliability. The former may allow discrimination between food types., Conclusion: As an alternative to the complex evaluation of masticatory function, observation of certain parameters from video recording could be an alternative for use in uncooperative patients.

The presence of a localization signal in the 3'-untranslated region of c-fos mRNA was investigated by in situ hybridization and cell fractionation techniques. Cells were transfected with chimeric gene constructs in which the beta-globin coding region was used as a reporter and linked to either its own 3'-untranslated region, the c-fos 3'-untranslated region, or the c-fos 3'-untranslated region containing different deletions. Replacement of the endogenous beta-globin 3'-untranslated region by that from c-fos caused a redistribution of the transcripts so that they were recovered in cytoskeletal-bound polysomes and seen localized in the perinuclear cytoplasm. Deletion of the AU-rich instability region did not affect transcript localization, but removal of a distinct 145-nucleotide region of the 3'-untranslated region abolished it. The prevention of transcript translation by desferrioxamine led to a marked loss of transcript localization, independent of mRNA instability. The data show that the 3'-untranslated region of c-fos mRNA, as c-myc, contains a localization signal, which targets the mRNA to the perinuclear cytoskeleton. We propose that this is important to ensure efficient nuclear import of these key regulatory proteins. mRNA localization by the fos 3'-untranslated region is independent of mRNA instability, and the two are determined by different regulatory elements.

This study was undertaken to evaluate the sensitivity of denture wearers to different food textures and to follow masticatory pattern adaptation with variation in texture using electromyography (EMG) recordings. Nine patients with complete dentures and 9 dentate control patients without any oro-dental pathology were studied. Six different samples of beef were obtained from the same muscle by altering the state of the muscle fibres and by variation of the cooking temperature. The variations in texture were mechanically controlled. Electromyographic activity was recorded during chewing. The patients' subjective appreciation of texture was reported using a 10-cm non-structured analogue scale. The following parameters were analysed: muscle work, number of masticatory cycles, number of rejected samples, initial tenderness, overall tenderness, juiciness, and duration of chewing for each sample in the mouth. Muscle activity was less for the edentulous group, particularly that of the masseter muscles. The masticatory pattern of complete denture wearers was less adapted to each sample texture than was that of the control group. Both groups perceived differences in texture of the samples. It was concluded that although texture perception is little altered, muscular adaptation to the bolus is reduced in patients with complete dentures.

Statement of Problem: Masticatory efficiency has been proposed as an outcome measure for prosthetic rehabilitation. However, no standardized method is available for this type of assessment., Purpose: This study developed a normalized synthetic test food with reproducible physical and rheologic properties., Material and Methods: Two silicone putties of different hardness were studied. The texture of each putty varied by the addition of silicone oil. Rheologic characteristics of 7 samples were compared with the same properties of 5 natural food substances., Results: Seven varieties of synthetic bolus were produced, each of which were of a different hardness, modulus of elasticity, and tensile strength. The natural food substances demonstrated great rheologic variability. The synthetic bolus samples exhibited a texture profile approaching that of natural foods. The principal difference between the 2 groups tested was that of the homogeneity of the silicone samples., Conclusion: None of the samples reproduced all the rheologic properties of the natural food substances; however, the results showed that their characteristics were sufficiently similar for the silicone samples to be suggested as a reproducible alternative for the testing of masticatory efficiency.

The late consultation in odontology often leads to tooth extraction. This negligence, in a long term, will cause complete toothlessness. This state of invalidity will be compensated by prosthesis. The removable prosthesis is often indicated because of the cost price. It is the result of a successful therapeutics, only if it fits aesthetically and functionally, within a chewing efficiency. In a first part, we will define masticatory efficiency, as different from masticatory capacity and capability. Then, in a second part, through some experimentation, we will show how fundamental research can guide the practitioner in his prosthetics choices and assessments.

There is increasing evidence that in mammalian cells some mRNAs are localised to specific parts of the cytoplasm and a proportion of mRNAs and polyribosomes are associated with the cytoskeleton. It has been shown previously that c-myc mRNA is present in the perinuclear cytoplasm and associated with the cytoskeleton, and that this localisation is dependent upon the 3' untranslated region of the mRNA. The present studies show that in transfected fibroblasts the c-myc 3' untranslated region is able to localise beta-globin reporter sequences to the perinuclear cytoplasm. Studies with constructs containing deletions within the 3' untranslated region identify the region between bases 194 and 280 as critical for localisation. Transfection of cells with constructs in which this region is linked to beta-globin sequences showed that it was sufficient to localise the chimaeric transcripts to the perinuclear cytoplasm and to cytoskeletal-bound polyribosomes. Transfection with constructs containing a mutated AUUUA sequence within the 194-280 base region showed that this conserved AUUUA is required for targeting of both c-myc mRNA and a chimaeric transcript of beta-globin transcripts linked to the c-myc 3' untranslated region. The region between bases 194 and 280 did not induce instability of beta-globin transcripts and the AUUUA mutation had little effect upon mRNA stability. We propose that this 86 nt region of the 3' untranslated region contains a localisation signal to target c-myc mRNA so that it is retained on cytoskeletal-bound polysomes in the perinuclear cytoplasm; a conserved AUUUA sequence appears to be a critical part of this signal.

The instability of oncogenic mRNA such as c-fos mRNA is controlled in cis by sequences present in both the coding and the 3' untranslated regions (3'UTR). The latter contains AU-rich elements (ARE) which, depending on the cellular context, mediate either their rapid degradation or inhibit their translation. These observations, along with the known increase of the life spans of many unstable mRNA promoted by inhibitors of protein synthesis, raise the possibility that both processes are linked. To investigate further the putative involvement of translation in both coding region and ARE-mediated rapid decay of c-fos mRNA, we designed an expression vector based on the use of the ferritin mRNA iron regulatory element (IRE). The latter structure links translation to intracellular iron concentration when inserted at the proper location within the 5'UTR. Rapid degradation of a beta-globin/c-fos 3'UTR construct was prevented by Desferrioxamine, an iron chelator, and facilitated by ferric ammonium citrate or hemin, while stability of other mRNAs not containing the IRE or the ARE were unchanged. The same conclusion was reached when the stability of a c-fos mRNA devoid of ARE was assessed in function of iron availability.