Objective. The aim of the study was to provide data on the fracture strength of monolithic high translucent Y-TZP crowns and porcelain-veneered high translucent Y-TZP crown cores and to compare that data with the fracture strength of porcelain-veneered Y-TZP crown cores and monolithic lithium disilicate glass-ceramic crowns. Materials and methods. Sixty standardized crowns divided into six groups (n = 10) were fabricated: monolithic high translucent Y-TZP crowns, brand A, monolithic high translucent Y-TZP crowns, brand B, veneered high translucent Y-TZP crown cores, brand A, veneered high translucent Y-TZP crown cores, brand B, heat-pressed monolithic lithium disilicate crowns and veneered Y-TZP crown cores. All crowns were thermocycled, cemented onto dies, cyclically pre-loaded and finally loaded to fracture. Results. The monolithic Y-TZP groups showed significantly higher fracture strength (2795 N and 3038 N) compared to all other groups. The fracture strength in the veneered Y-TZP group (2229 ...

Fracture strength of monolithic all-ceramic crowns made of high translucent yttrium oxide-stabilized zirconium dioxide compared to porcelain-veneered crowns and lithium disilicate crowns

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Le soin pulpaire chez l’enfant Constance Renaud

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Diplôme d'état de docteur en chirurgie dentaire

OBJECTIVE: Some factors such as gender, age, craniofacial morphology, body structure, occlusal contact patterns may affect the maximum bite force. Thus, the purposes of this study were to determine the mean maximum bite force in individuals with normal occlusion, and to examine the effect of gender, facial dimensions, body mass index (BMI), type of functional occlusion (canine guidance and group function occlusion) and balancing side interferences on it. MATERIAL AND METHODS: Thirty-four individuals aged 19-20 years-old were selected for this study. Maximum bite force was measured with strain-gauge transducers at first molar region. Facial dimensions were defined by standardized frontal photographs as follows: anterior total facial height (ATFH), bizygomathic facial width (BFW) and intergonial width (IGW). BMI was calculated using the equation weight/height². The type of functional occlusion and the balancing side interferences of the subjects were identified by clinical examination. RESULTS: Bite force was found to be significantly higher in men than women (p 0.05). BMI and bite force correlation was not statistically significant (p>0.05). The average bite force did not differ in subjects with canine guidance or group function occlusion and in the presence of balancing side interferences (p>0.05). CONCLUSIONS: Data suggest that bite force is affected by gender. However, BMI, type of functional occlusion and the presence of balancing side interferences did not exert a meaningful influence on bite force. In addition, transverse facial dimensions showed correlation with bite force in only men.

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Effect of gender, facial dimensions, body mass index and type of functional occlusion on bite force

Masticatory efficiency and bite force in individuals with normal occlusion.

Summary
To determine whether maximum bite force (MBF), an objective measure of oral function, is associated with development of frailty in community-dwelling older adults. This prospective cohort study included community-dwelling Japanese adults aged 75 years at baseline (n = 322). Baseline MBF was measured using an electronic recording device (Occlusal Force-Meter GM10). Follow-up examinations, including physical fitness and anthropometric evaluation and structured questionnaires, were administered annually over a 5-year period to determine the incidence of frailty, which was defined by the presence of 3 or more of the following 5 components derived from the Cardiovascular Health Study: low level of mobility, low physical activity level, weakness, shrinking and poor endurance and energy. Adjusted hazard ratios (HRs) of incidence of frailty according to sex-stratified tertiles of baseline MBF were calculated using Cox proportional hazards regression models. During the follow-up, 49 participants (15.2%) developed frailty. Participants in the lower tertile of MBF exhibited a significantly greater risk of frailty than those in the upper tertile. After adjustment for sex, depression, diabetes and Eichner index, the adjusted HRs for frailty in the upper through lower tertiles of MBF were 1.00 (reference), 1.27 (95% confidence interval [CI]: 0.50-3.20) and 2.78 (95% CI: 1.15-6.72), respectively (P for trend = .01). Poor oral function, as indicated by low MBF, increases the risk of development of frailty among elderly men and women.

A 5-year longitudinal study of association of maximum bite force with development of frailty in community-dwelling older adults

Maximum voluntary bite force is an indicator of the functional state of the masticatory system and the level of maximum bite force results from the combined action of the jaw elevator muscles modified by jaw biomechanics and reflex mechanisms. The measurement of bite force can provide useful data for the evaluation of jaw muscle function and activity. It is also an adjunctive value in assessing the performance of dentures. Technological advances in signal detection and processing have improved the quality of the information extracted from bite force measurements. However, these measurements are difficult and the reliability of the result depends on a number of factors, such as presence of pain and temporomandibular disorders, gender, age, cranio-facial morphology, and occlusal factors. In addition to these physiological factors, recording devices and techniques are important factors in bite force measurement. Therefore, one should be careful when comparing the bite force values reported in the research.

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Bite force and influential factors on bite force measurements: a literature review.

Effects of increasing the jaw opening on the maximum bite force and electromyographic activities of jaw muscles

Chenille yarn has an increasing share of use in the upholstery fabric sector recently. To have an important place in chenille yarn production in the world, it has become necessary for manufacturers to improve the quality, durability, and performance of their products and to carry out innovative studies in this field. Increasing the abrasion resistance of the yarns that form the basis of upholstery fabrics will significantly affect the service life performance. In this study, two raw materials selected with different production parameters were examined. These raw materials are determined as viscose and polyester, which are mostly used for chenille yarn in the production facility. The parameters covered in this study are determined and evaluated as the fixed/unfixed state of the yarn, the state of having different twist values, and the presence or absence of melted yarn added to ensure better adhesion of the pile and binder yarn with each other. In this direction, to test the abrasion resistance of the yarns produced from 6 polyester raw materials and 6 viscose raw materials with different properties, they are woven into fabrics by weaving on a 65-density jacquard loom. Each fabricated sample is realized by Martindale test. This test is realized to see the result of friction force and impact effect on the fabric surface. Also, it is aimed to determine the resistance of the samples against pilling and surface change. Based on the results, different parameters affecting the abrasion resistance of upholstery fabrics obtained from chenille yarn were interpreted and it was aimed to be a pioneering study in this field.

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Duygu Koc

Papers

Bite force and influential factors on bite force measurements: a literature review.

Effect of gender, facial dimensions, body mass index and type of functional occlusion on bite force

Effects of increasing the jaw opening on the maximum bite force and electromyographic activities of jaw muscles

Chenille Yarn Production Parameters Improvement Studies and Evaluation of Their Effects