The key elements of conducting load-to-fracture mechanical testing on restoration-tooth units in restorative dentistry

Biomimetic restorative dentistry strives to replace lost tooth tissue by biomaterials with similar physical properties. In order to do so, mechanical testing of dental restorative materials on their own and later in dental cavities is highly important. During this process dentists and engineers are collaborating aiming to set the indications of certain restorative materials and application techniques. In vitro fracture resistance testing of a restored tooth is one of the most important tests to be carried out during the indication setting process. However, for this specific test and received results to be valid for clinicians, the group conducting the tests must pay attention to mimic intraoral conditions as much as possible. The article aims at identifying the key elements of fracture resistance tests in dentistry. Adequately conducting this test is a prerequisite for later testing in in vivo conditions the restorative techniques that produced the best results among the in vitro tests

Kernel hardness and dough reological investigation on different wheat varieties

The aim of this research was the investigation of winter wheat varieties, the kernel hardness and the dough features. We determined the kernel hardness with two dynamic methods. We measured the parameters of flour. The correlations among hardness index and the examined flour parameters were also significant (r=0.816-0.876). We found strong correlation between the grinding energy (eg) and water absorption (r=0.878) of the flour. Hardness Index – wet gluten (r=0.833), and Hardness Index – water absorption (r=0.876), Hardness Index – P value of alveograph (r=0.816) showed also positive correlations. We found correlation the water absorption and P value of alveograph (r=0.873)

The biomechanical effect of root amputation and degree of furcation involvement on intracoronally splinted upper molar teeth – An in vitro study

Objectives: The aim of this study was to evaluate the effect of the amount of periodontal support and the presence or absence of root amputation on the fracture resistance of intracoronally splinted maxillary molar teeth.Materials and methods: 48 extracted human upper first molars and 48 s premolars were included in the study. All teeth underwent standard mesio-occluso-distal (MOD) (molars) and standard occluso-distal (OD) (premolars) cavity preparation. After the preparation, all molars were root canal treated, and 48 molar-premolar units were created by intracoronal splinting. The units were randomly divided into 4 groups (Groups A-D, 12 units per group): in Groups C and D, the disto-buccal (DB) roots of the molars were amputated, while in Groups A and B, no root amputation was performed. All units were embedded in methacrylate resin at different levels: in Groups A and C, at 4 mm apically from the cemento-enamel junction (CEJ), while in Groups B and D, at 6 mm apically from the CEJ, mimicking the different stages of furcation involvement. All units were submitted first to dynamic and then to static, load-to-fracture mechanical testing. Fracture resistance values were recorded fracture mode was analysed.Results: During the load-to-facture test, Groups A and B (without root amputation) were characterized by significantly higher fracture resistance values compared to Groups C and D (with root amputation) (p Conclusions: Root amputation has a negative effect on the fracture resistance of intracoronally splinted upper first molar-second premolar units with modeled furcation involvement.</p

Analog and digital modeling of sound and impaired periodontal supporting tissues during mechanical testing

Periodontitis is one of the most common conditions affecting oral health among adults, posing a great challenge for both patients and also for dentists aiming to treat this disease. In severe stages such deterioration of the supporting tissues, namely the periodontal ligaments and the bone, can occur, which will affect the biomechanical behavior and therefore the longevity and survival of the affected teeth. In order to be able to plan both periodontal and subsequent restorative treatment properly, valid modelling of the current clinical situation is advised. The aim of the present article is to comprehensively discuss possible analog and digital modeling methods of periodontally affected teeth and the periodontal structures surrounding them. Modelling possibilities can serve later as the basis of mechanical load, digital finite element studies, and also aid clinical treatment planning

Analog and digital modeling of sound and impaired periodontal supporting tissues during mechanical testing

Periodontitis is one of the most common conditions affecting oral health among adults, posing a great challenge for both patients and also for dentists aiming to treat this disease. In severe stages such deterioration of the supporting tissues, namely the periodontal ligaments and the bone, can occur, which will affect the biomechanical behavior and therefore the longevity and survival of the affected teeth. In order to be able to plan both periodontal and subsequent restorative treatment properly, valid modelling of the current clinical situation is advised.&nbsp;The aim of the present article is to comprehensively discuss possible analog and digital modeling methods of periodontally affected teeth and the periodontal structures surrounding them. Modelling&nbsp;possibilities can serve later as the basis of mechanical load, digital finite element studies, and also aid clinical treatment planning

Fehérje komplettált gabonatartalmú szeletek kifejlesztése és piaci helyzete

A sportolók körében a fehérjeporok preferált étrend-kiegészítő terméknek számítanak. Hazánkban számos fehérjekészítmény közül választhatnak a fizikai aktivitást végzők, eltérő minőségben és árban egyaránt. A kutatás során igyekeztünk felmérni sportolók körében a fehérjeporok fogyasztási szokásait, illetve a kapott eredmények alapján a fehérjebevitel formái közül a müzliszeletek jelentőségét is tanulmányoztuk. A kérdőíves felmérésben a 196 válaszadótól kapott információk alapján három különböző növényi (rizs, borsó, szója) és állati (tejsavó, marhahús, tojás) izolátumok mellett döntöttünk, melyekkel müzliszeleteket komplettáltunk. Továbbá alapanyag költséget is meghatároztunk egyszerű osztókalkulációs módszerrel, mely során átlagos piaci nettó árakkal számoltunk, így a fehérjedúsítással átlagosan 103 Ft-ra becsülhető 1 adag (35 g) müzliszelet közvetlen anyagköltsége. Fontos kérdés a termék piaci helyzete, ezért a boltban kapható, hasonló felépítésű termékekkel is összehasonlítottuk a készterméket, hogy megállapíthassuk a tápértékbeli különbségeket is. Meghatározó azonban az egyes allergének jelenléte a termékben, ezért a fogyasztókhoz alkalmazkodva szükségszerű a folyamatos fejlesztés. Abstract: Protein powders are the preferred dietary supplement among athletes. In our country, there is a wide range of protein products available to people who are physically active, in varying quality and price. In this research, we have tried to assess the consumption habits of protein powders among athletes and, based on the results obtained, we have also studied the importance of muesli bars as a form of protein intake. In the questionnaire survey, based on the information obtained from 196 respondents, three different vegetable (rice, peas, soy) and animal (whey, beef, eggs) isolates were chosen to complete muesli bars. Furthermore, we estimated the cost of the raw materials using a simple fractional costing method based on average net market prices, so that the direct material cost of 1 portion (35 g) of muesli bars with protein fortification was estimated at 103 HUF on average. The market position of the product is an important issue, so we also compared the finished product with products of similar structure available in the shops to determine the differences in nutritional value. However, the presence of certain allergens in the product is crucial and continuous improvement is necessary to adapt to consumer needs

Measuring the wheat kernel hardness

The wheat kernel hardness determines quality, flour recovery, flour grain size, water absorption, etc. The hardness is determined by the degree of adhesion between various components of the starchy endosperm cells of the mature wheat grain, notably between starch granules and matrix (gluten) proteins but also between proteins and cell walls. Hard textured grains require more grinding energy than soft textured grains to reduce endosperm into flour, and during this milling process a larger number of starch granules become physically damaged. We have to know that the kernel hardness is soft or hard, because it determines the milling process, so we have to measure it. (Békési, 2001) In our investigation we used three methods to measuring kernel hardness. There were two dynamic methods the Perten Single Kernel Characterization System (SKCS) 4100 device and the Perten 3303 mill and there was a static test, it was the Lloyd 1000 R Material Testing Machines. Our aim was to compare these methods

Behaviour of flexible/elastic materials under quasi-static force

Elasticity and stress absorption are present in many different materials in our daily life. Understanding how materials behave under pressure (whether that is constant or dynamic), and how and when they deform can be fundamental in terms of their success or longevity. Elastic behaviour is present in many different forms in different materials, e.g.: meats or other food. Interestingly, elasticity is also a major issue in the oral cavity, when talking about healthy dental tissues, such as dentin or even special dental restorative materials. The article focuses on the general mechanical behaviour of elastic and viscoelastic materials and measurements performed on them