scholarly journals In Vitro Study Regarding the Biomechanical Behaviour of Bone and Periodontal Splints I.Model validation

2019 ◽  
Vol 56 (4) ◽  
pp. 1013-1020
Author(s):  
Raluca Maria Vieriu ◽  
Oana Tanculescu ◽  
Florentina Mocanu ◽  
Sorina Mihaela Solomon ◽  
ioan Gabriel Sandu ◽  
...  
Keyword(s):  
Bone Resorption ◽  
In Vitro Study ◽  
Dental Arch ◽  
Bone Strain ◽  
Arch Model ◽  
Mandibular Bone ◽  
Different Types ◽  
The Subject ◽  
Two Stages

This paper is part of a larger study that aims to evaluate the biomechanical behaviour of mandibular bone and periodontal splinting systems subjected to different occlusal forces by means of electric resistive tensometry (ERT). The research was based on the following premise: the degree of bone resorption and periodontal type of splint influence the deformation of the mandibular bone. The study was conducted in two stages: first, the validation of the mandibular dental arch model, which is the subject of the present article, and second, the evaluation of mandibular bone strain in case of different types of bone loss and periodontal splints, which is the subject of a second article.

scholarly journals Linear Accuracy of Full-Arch Digital Models Using Four Different Scanning Methods: An In Vitro Study Using a Coordinate Measuring Machine

2020 ◽  
Vol 10 (8) ◽  
pp. 2741 ◽  
Author(s):  
Young Hyun Kim ◽  
Sang-Sun Han ◽  
Yoon Joo Choi ◽  
Chang-Woo Woo
Keyword(s):  
Coordinate Measuring Machine ◽  
In Vitro Study ◽  
Dental Arch ◽  
Accuracy Evaluation ◽  
Arch Model ◽  
Linear Measurements ◽  
Scanning Method ◽  
True Model ◽  
Measuring Machine

Improving the accuracy of the digital model is essential for the digitalization of the dental field. This study introduced a novel method of objective accuracy evaluation of digitized full dental arch model using coordinate measuring machine (CMM). To obtain a true linear measurement value using the CMM, 17 reference balls were attached to the typodont, and 12 measurements between balls on the X-(width), Y-(length), and Z-axes (height) were performed automatically. A rubber impression and a plaster cast replica of the typodont with balls were fabricated, and they were digitized with following methods: (a) true model intraoral scans; (b) impression cone-beam computed tomography (CBCT) scans; (c) cast CBCT scans; and (d) cast extraoral scans. Each scanning method was performed 20 times. Twelve linear measurements on the digitized models were automatically made using software. The one-sample t-test and one-way analysis of variance were used for measurement accuracy analysis. The cast extraoral scan was most accurate on X- and Y-axes, while impression CBCT was the most accurate on Z-axis. Over all axes, the intraoral scan resulted in the most deviation from the true model, and the reproducibility of each scan was also low. Extraoral scan shows high precision on width and length, and impression CBCT is advantageous for dental work where height factor is of importance.

scholarly journals Efficient palatal expansion with a quadhelix appliance: an in vitro study using an experimental dental arch model

2011 ◽  
Vol 34 (4) ◽  
pp. 442-446
Author(s):  
Y. Honme ◽  
M. Motoyoshi ◽  
A. Shinohara ◽  
T. Shigeeda ◽  
N. Shimizu
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Dental Arch ◽  
Arch Model ◽  
Palatal Expansion

scholarly journals Complete-Arch Accuracy of Four Intraoral Scanners: An In Vitro Study

Healthcare ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 246
Author(s):  
Giordano Celeghin ◽  
Giulio Franceschetti ◽  
Nicola Mobilio ◽  
Alberto Fasiol ◽  
Santo Catapano ◽  
...  
Keyword(s):  
Reference Model ◽  
In Vitro Study ◽  
Reference Points ◽  
Dental Arch ◽  
Arch Model ◽  
Linear Measurements ◽  
Stl File ◽  
Digital Reference ◽  
Digital Impressions

The purpose of this study is to define the accuracy of four intraoral scanners (IOS) through the analysis of digital impressions of a complete dental arch model. Eight metal inserts were placed on the model as reference points and then it was scanned with a laboratory scanner in order to obtain the reference model. Subsequently, the reference model was scanned with four IOS (Carestream 3600, CEREC Omnicam, True Definition Scanner, Trios 3Shape). Linear measurements were traced on an STL file between the chosen reference points and divided into four categories: three-element mesiodistal, five-element mesiodistal, diagonal, and contralateral measurements. The digital reference values for the measurements were then compared with the values obtained from the scans to analyze the accuracy of the IOS using ANOVA. There were no statistically significant differences between the measurements of the digital scans obtained with the four IOS systems for any of the measurement groups tested.

scholarly journals In Vitro Study Regarding the Biomechanical Behaviour of Bone, Fibre Reinforced Polymer and Wire Composite Perio-dontal Splints. Model Analysis

2020 ◽  
Vol 57 (1) ◽  
pp. 253-262
Author(s):  
Raluca Maria Vieriu ◽  
Oana Taculescu ◽  
florentina Mocanu ◽  
Sorina Mihaela Solomon ◽  
Carmen Savin ◽  
...  
Keyword(s):  
Bone Resorption ◽  
In Vitro Study ◽  
Normal Height ◽  
Mandibular Bone ◽  
Load Distributions ◽  
Polyethylene Fiber ◽  
Bone Strains ◽  
Fibre Reinforced Polymer ◽  
Bone Condition

This paper is the second part of a study regarding the biomechanical behaviour of mandibular bone in the context of different periodontal splinting systems, occlusal forces and load distributions. Electric resistive tensometry method was used to measure the strains developed in mandibular bone replica. The tests were carried out on six mandibular acrylic models, each with 8 natural teeth. The experimental groups were defined corresponding to the bone condition and splint type: normal height bone; bone resorption without splint; bone resorption and wire-composite splint; bone resorption and polyethylene fiber-reinforced composite splint. Each sample was subjected to three similar loading cycles, the force being applied successively on four incisors, two central incisors and canines, and the specific deformation values were read for four loading forces: 30 N, 50 N, 100 N and 150 N. In case of bone loss, the bone deformations are up to 110%. Periodontal splinting redistribute forces, reducing incisors bone strains associated with a slight increase in canine bone strains.

scholarly journals Marginal Adaptation and Micropermeability of Class II Cavities Restored with Three Different Types of Resin Composites—A Comparative Ten-Month In Vitro Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1660
Author(s):  
Sevda Mihailova Yantcheva
Keyword(s):  
Methylene Blue ◽  
In Vitro Study ◽  
Sem Analysis ◽  
Marginal Adaptation ◽  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Gingival Margin ◽  
Different Types ◽  
Ageing Period

The development of composite materials is subject to the desire to overcome polymerization shrinkage and generated polymerization stress. An indicator characterizing the properties of restorative materials, with specific importance for preventing secondary caries, is the integrity and durability of marginal sealing. It is a reflection of the effects of polymerization shrinkage and generated stress. The present study aimed to evaluate and correlate marginal integrity and micropermeability in second-class cavities restored with three different types of composites, representing different strategies to reduce polymerization shrinkage and stress: nanocomposite, silorane, and bulk-fill composite after a ten-month ageing period. Thirty standardized class ΙΙ cavities were prepared on extracted human molars. Gingival margins were 1 mm apical to the cementoenamel junction. Cavities were randomly divided into three groups, based on the composites used: FiltekUltimate-nanocomposite; Filtek Silorane LS-silorane; SonicFill-bulk-fill composite. All specimens were subjected to thermal cycles after that, dipped in saline for 10-mounds. After ageing, samples were immersed in a 2% methylene blue. Thus prepared, they were covered directly with gold and analyzed on SEM for assessment of marginal seal. When the SEM analysis was completed, the teeth were included into epoxy blocks and cut longitudinally on three slices for each cavity. An assessment of microleakage on stereomicroscope followed. Results were statistically analyzed. For marginal seal evaluation: F.Ultimate and F.Silorane differ statistically with more excellent results than SonicFill for marginal adaptation to the gingival margin, located entirely in the dentin. For microleakage evaluation: F.Ultimate and F.Silorane differ statistically with less microleakage than SonicFill. Based on the results obtained: a strong correlation is found between excellent results for marginal adaptation to the marginal gingival ridge and micropermeability at the direction to the axial wall. We observe a more significant influence of time at the gingival margin of the cavities. There is a significant increase in the presence of marginal fissures (p = 0.001). A significant impact of time (p < 0.000) and of the material (p < 0.000) was found in the analysis of the microleakage.

In-Vitro Study of Bacterial Adherence to Different Types of Intraocular Lenses

2002 ◽  
Vol 28 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Carole Burillon ◽  
Laurent Kodjikian ◽  
Gérard Pellon ◽  
Annie Martra ◽  
Jean Freney ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Bacterial Adherence ◽  
Vitro Study ◽  
Intraocular Lenses ◽  
Different Types

The Influence of Using Different Types of Scan Bodies on the Transfer Accuracy of Implant Position: An In Vitro Study

2021 ◽  
Vol 34 (2) ◽  
pp. 254-260
Author(s):  
Alexander Schmidt ◽  
Jan-Wilhelm Billig ◽  
Maximiliane Schlenz ◽  
Bernd Wöstmann
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Implant Position ◽  
Different Types ◽  
Transfer Accuracy

Evaluation of the marginal microleakage of CAD-CAM compared with conventional interim crowns luted with different types of cement: An in-vitro study

2021 ◽  
Vol 24 (6) ◽  
pp. 828
Author(s):  
A Robaian ◽  
A Maawadh ◽  
ZI Alghomlas ◽  
AM Alqahtani ◽  
TA Alothman ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Different Types ◽  
Cad Cam

Hypoxia and acidosis increase the secretion of catecholamines in the neonatal rat adrenal medulla: an in vitro study

2005 ◽  
Vol 289 (6) ◽  
pp. C1417-C1425 ◽  
Author(s):  
A. J. Rico ◽  
J. Prieto-Lloret ◽  
C. Gonzalez ◽  
R. Rigual
Keyword(s):  
Adrenal Medulla ◽  
In Vitro Study ◽  
Neonatal Rat ◽  
Hypercapnic Acidosis ◽  
Hypoxic Response ◽  
High K ◽  
Old Rats ◽  
The Subject ◽  
Direct Sensitivity

Hypoxia elicits catecholamine (CA) secretion from the adrenal medulla (AM) in perinatal animals by acting directly on chromaffin cells. However, whether innervation of the AM, which in the rat occurs in the second postnatal week, suppresses this direct hypoxic response is the subject of debate. Opioid peptides have been proposed as mediators of this suppression. To resolve these controversies, we have compared CA-secretory responses with high external concentrations of K+ ([K+]e) and hypoxia in the AM of neonatal (1- to 2-day-old) and juvenile (14- or 15- and 30-day-old) rats subjected to superfusion in vitro. In addition, we studied the effect of hypercapnic acidosis on the CA-secretory responses in the AM during postnatal development and the possible interaction between acidic and hypoxic stimuli. Responses to high [K+]e were comparable at all ages, but responses to hypoxia and hypercapnic acidosis were maximal in neonatal animals. Suppression of the hypoxic response in the rat AM was not mediated by opioids, because their agonists did not affect the hypoxic CA response. The association of hypercapnic acidosis and hypoxia, mimicking the episodes of asphyxia occurring during delivery, generates a more than additive secretory response in the neonatal rat AM. Our data confirm the loss of the direct sensitivity to hypoxia of the AM in the initial weeks of life and demonstrate a direct response of neonatal AM to hypercapnic acidosis. The synergistic effect of hypoxia and acidosis would explain the CA outburst crucial for adaptation to extrauterine life observed in naturally delivered mammals.

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