scholarly journals The Accuracy of Three Intraoral Scanners in the Oral Environment with and without Saliva: A Comparative Study

2020 ◽  
Vol 10 (21) ◽  
pp. 7762 ◽  
Author(s):  
Biagio Rapone ◽  
Cosimo Palmisano ◽  
Elisabetta Ferrara ◽  
Daniela Di Venere ◽  
Giovanni Albanese ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Descriptive Analysis ◽  
Digital Impression ◽  
Standards Of Care ◽  
Permanent Teeth ◽  
Diagnostic Efficacy ◽  
Significance Level ◽  
Intraoral Scanning ◽  
Scanning Systems

Background: with the emergence of technological innovations in the dental industry, one emerging trend has been the intraoral digitizing of patients by using intraoral scanning systems. Compared to taking conventional impressions, the use of intraoral scanners (IOS) is suitable for capturing direct optical impressions, helping to improve diagnostic efficacy, save time, reduce patient discomfort, and simplify clinical procedures. Intraoral scanning systems appear to have a high potential for providing guidance on proper standards of care. However, one main disadvantage is breathing and saliva secretion, which causes deviations, interfering with the applicability and accuracy of the optical impression. The aim of this study was to compare the validity and accuracy of three commercially available intraoral scanners, performing an analysis exploiting a wet model. Methods: an in vitro experimental study of four permanent teeth (two molars and two premolars) on the accuracy of copings obtained by subgingival preparations was performed, using an oral wet environment model. Two hundred and forty digital impressions were produced from three digital scanners using four samples. Descriptive analysis was performed using mean, standard deviation, and median. ANOVA and F-tests were performed to assess the amount of variability between the groups. For statistical analysis a 95% significance level was chosen. Results: all differences between groups were statistically significant. Conclusions: the present data implicate a huge impact of the oral biological fluids on the accuracy of digital impression to corresponding images, implying a failure of accurate impression under wetness conditions.

scholarly journals Microbiological Sealing Analysis of a Tapered Connection and External Hexagon System

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Gardel Nepomuceno Costa ◽  
Elizabeth Ferreira Martinez ◽  
Aluísio Martins de Oliveira Ruellas ◽  
Daiane Cristina Peruzzo ◽  
Júlio Cesar Joly ◽  
...  
Keyword(s):  
Descriptive Analysis ◽  
In Vitro Study ◽  
Positive Control ◽  
Negative Control ◽  
Microbiological Analysis ◽  
Significance Level ◽  
Implant Abutment ◽  
Bacterial Leakage ◽  
Tapered Connection

Considering the variety of implant connection systems available in the market and the contrasting literature regarding tapered connection systems in terms of bacterial leakage, the aim of this in vitro study was to compare the effectiveness of the bacterial seal at the implant/abutment interface between an external hexagon and a tapered connection system. Twelve sets of indexed tapered connection components and twelve sets of external hexagon connection components were used for microbiological analysis. In addition, for each model, an implant with its respective prosthetic abutment was used as a negative control and another as a positive control of microbial contamination. Failure of the abutment/implant interface seal was observed via turbidity or presence of deposits in the culture. Descriptive analysis of the data and relative frequency (percentage) as well as Fisher’s exact test were used at a significance level of 5%. Two of ten (20%) external hexagon specimens showed contamination against 0/10 (0%) tapered connection implants. In conclusion, both implant/abutment connections were able to prevent bacterial leakage in vitro.

scholarly journals Multivariate Assessment of Marginal Fit of Three Types of Dental Crowns Using Three Scanning Systems for CAD-CAM Technology - in vitro Pilot Study

2018 ◽  
Vol 55 (3) ◽  
pp. 376-379
Author(s):  
Smaranda Buduru ◽  
Anca Mesaros ◽  
Cristian Culcitchi ◽  
Marioara Moldovan ◽  
Doina Prodan ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Marginal Fit ◽  
Dental Crowns ◽  
Intraoral Scanning ◽  
Different Types ◽  
Cad Cam ◽  
Scanning Systems ◽  
Conventional Impression ◽  
Hybrid Ceramic

The objective of this in-vitro study was to compare if there are any differences in the marginal fit of crowns fabricated by CAD/CAM technique. We used three different types of materials (two types of polymethylmetacrylate (PMMA) provided by two different manufacturers and one type of hybrid ceramic) and three different types of impressions: intraoral scanning, model scanning and conventional impression scanning. The crowns were subsequently measured with an electronic microscope at 1000X. Our results showed better results for the hybrid ceramic. The differences between the PMMA were not significant. There were no statistic differences with the ANOVA analysis between the scanning methods. Best combination in terms of marginal fit was found with hybrid ceramic and intraoral scanning.

scholarly journals Accuracy of Implant Level Intraoral Scanning and Photogrammetry Impression Techniques in a Complete Arch with Angled and Parallel Implants: An In Vitro Study

2021 ◽  
Vol 11 (21) ◽  
pp. 9859
Author(s):  
Hani Tohme ◽  
Ghida Lawand ◽  
Rita Eid ◽  
Khaled E. Ahmed ◽  
Ziad Salameh ◽  
...  
Keyword(s):  
In Vitro Study ◽  
High Accuracy ◽  
Vitro Study ◽  
Digital Impression ◽  
P Value ◽  
Angular Deviation ◽  
Digital Photogrammetry ◽  
Intraoral Scanning ◽  
Optical Markers

(1) Background: Stereophotogrammetry has recently been investigated showing high accuracy in complete implant supported cases but has scarcely been investigated in cases of tilted implants. The aim of this in vitro study was to compare the accuracy of digital impression techniques (intraoral scanning and photogrammetry) at the level of intraoral scan bodies in terms of angular deviations and 3D discrepancies. (2) Methods: A stone master cast representing an edentulous maxilla using four implant analogs was fabricated. The two anterior implants were parallel to each other, and the two posterior implants were at an angulation of 17 degrees. Digital intraoral scanning (DIOS) impressions were taken after connecting implant level scan bodies to the master cast and STL files were exported (n = 15). Digital photogrammetry (DPG) impressions were captured using a PiC Camera after tightening implant level PiC optical markers and STL files were exported (n = 15). Superimposition was carried out by a software for determining the accuracy of both. (3) Results: Significant angular discrepancies (ΔA) and 3D deviations of scan bodies were found among the groups in trueness with lower deviations for the DPG (p value < 0.001). However, trueness within ISBs varied between angular and 3D deviations and outcomes were not specific to determine the effect of implant angulation. In precision, no significant differences were detected within ISBs and among both groups in terms of angular deviation. However, DPG had less deviations than DIOS group in terms of 3D deviations (p value < 0.001). (4) Conclusion: Digital photogrammetry technique conveyed the utmost accuracy in both trueness and precision for the intraoral scan bodies among both impression methods assessed. In addition, implant angulation did not influence the precision of the impression techniques but affected their trueness without explicit conclusions.

Stem Cells Derived from Human Exfoliated Deciduous teeth [shed] in Neuronal Disorders: A Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Minu Anoop ◽  
Indrani Datta
Keyword(s):  
Stem Cells ◽  
Neurodegenerative Diseases ◽  
Dental Pulp ◽  
Therapeutic Potential ◽  
Permanent Teeth ◽  
Deciduous Teeth ◽  
Proliferative Potential ◽  
Pulp Tissue ◽  
Human Exfoliated Deciduous Teeth

: Most conventional treatments for neurodegenerative diseases fail due to their focus on neuroprotection rather than neurorestoration. Stem cell‐based therapies are becoming a potential treatment option for neurodegenerative diseases as they can home in, engraft, differentiate and produce factors for CNS recovery. Stem cells derived from human dental pulp tissue differ from other sources of mesenchymal stem cells due to their embryonic neural crest origin and neurotrophic property. These include both dental pulp stem cells [DPSCs] from dental pulp tissues of human permanent teeth and stem cells from human exfoliated deciduous teeth [SHED]. SHED offer many advantages over other types of MSCs such as good proliferative potential, minimal invasive procurement, neuronal differentiation and neurotrophic capacity, and negligible ethical concerns. The therapeutic potential of SHED is attributed to the paracrine action of extracellularly released secreted factors, specifically the secretome, of which exosomes is a key component. SHED and its conditioned media can be effective in neurodegeneration through multiple mechanisms, including cell replacement, paracrine effects, angiogenesis, synaptogenesis, immunomodulation, and apoptosis inhibition, and SHED exosomes offer an ideal refined bed-to-bench formulation in neurodegenerative disorders. However, in spite of these advantages, there are still some limitations of SHED exosome therapy, such as the effectiveness of long-term storage of SHED and their exosomes, the development of a robust GMP-grade manufacturing protocol, optimization of the route of administration, and evaluation of the efficacy and safety in humans. In this review, we have addressed the isolation, collection and properties of SHED along with its therapeutic potential on in vitro and in vivo neuronal disorder models as evident from the published literature.

scholarly journals Artificial Caries Lesion Characteristics after Secondary Demineralization with Theobromine-Containing Protocol

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 300
Author(s):  
Hani M. Nassar ◽  
Frank Lippert
Keyword(s):  
Mineral Content ◽  
Significance Level ◽  
Lesion Depth ◽  
Caries Lesion ◽  
Mineral Profile ◽  
Bonferroni Test ◽  
Bovine Enamel ◽  
Caries Lesions ◽  
Nail Varnish

Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate artificial caries lesion characteristics after secondary demineralization protocol containing theobromine and fluoride. Sixty bovine enamel slabs (4 × 3 mm) were demineralized using a Carbopol-containing protocol for 6 days. A baseline area (2 × 3 mm) was protected with acid-resistant nail varnish, after which specimens were exposed for 24 h to a secondary demineralization protocol containing acetic acid plus one of four fluoride/theobromine combinations (n = 15): theobromine (50 or 200 ppm) and fluoride (0 or 1 ppm). Specimens were sectioned and analyzed using transverse microradiography for changes in mineral content, lesion depth, and surface layer mineralization. Data was analyzed using paired t-test and analysis of variance followed by Bonferroni test at 0.05 significance level. After secondary demineralization, fluoride-containing groups had significantly deeper lesions (p = 0.002 and 0.014) compared to the group with 0 ppm fluoride and 50 ppm theobromine. Mineral content and lesion depth were significantly different compared to baseline for all groups. Theobromine did not show an added effect on mineral uptake. Theobromine-containing groups exhibited particularly deep lesions with a more uniform mineral profile in the presence of fluoride.

Diagnostic Efficacy of in Vitro Methods vs. Skin Testing in Patients with Inhalant Allergies

1991 ◽  
Vol 104 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Jacquelynne P. Corey ◽  
J.J. Liudahl ◽  
S.A. Young ◽  
S.M. Rodman
Keyword(s):  
Skin Testing ◽  
Diagnostic Efficacy ◽  
In Vitro Methods

scholarly journals Effect of commercially available and experimental potassium oxalate-based dentin desensitizing agents in dentin permeability: influence of time and filtration system

2006 ◽  
Vol 17 (4) ◽  
pp. 300-305 ◽  
Author(s):  
Sérgio Lima Santiago ◽  
José Carlos Pereira ◽  
Ana Christina Bonato Figueiredo Martineli
Keyword(s):  
Hydraulic Conductance ◽  
Potassium Oxalate ◽  
Group V ◽  
Significance Level ◽  
Group Iii ◽  
Dentin Permeability ◽  
Group I ◽  
Filtration System ◽  
Desensitizing Agents

This study evaluated the influence of time after application of oxalate solutions in reducing dentin hydraulic conductance. Fifty dentin discs were obtained from extracted human third molars and assigned to 5 groups (n=10), according to the desensitizing agent used: Group I: OxaGel; Group II: experimental agent DD-1: Group III: experimental agent DD-2. In Groups IV and V, a placebo gel and deionized water were used as control, respectively. The agents were applied for 3 min, washed out and the hydraulic conductance was measured immediately and at 5-, 15- and 30-min intervals, and after acid etching. Data were analyzed statistically by two-way ANOVA and Duncan's test at 5% significance level. Groups I, II and III did not differ significantly from each other in any of the time intervals (p>0.05). Likewise, Groups IV and V were statistically similar to each other (p>0.05). The active agents reduced significantly dentin permeability in comparison to control groups (p<0.05). Dentin permeability measured in vitro decreased significantly with time regardless of the agent applied (either active or control agents). The results of Group V, in which no dentin desensitizing agent was employed, indicates that the assessment of dentin permeability by this method must be interpreted with caution.

Abstract 8: Transplantation of Mouse Adipose Derived Stem Cell Sheet into Infarcted Rat Myocardium Increase Cell Engraftment and Cardiac Function

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Jong-Ho Kim ◽  
Hyung Joon Joo ◽  
Ha-Rim Seo ◽  
Long-Hui Cui ◽  
Mi-Na Kim ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Therapy ◽  
Cell Sheet ◽  
The Other ◽  
Differentiation Potential ◽  
Significance Level ◽  
Infarct Region ◽  
Cell Engraftment ◽  
Cell Proliferation And Differentiation

Background: Cell sheet technology has magnified as an important transplantation skill. Mouse adipose derived stem cells (mADSCs) can secrete various growth factors, which promote the repair of damaged cardiomyocyte and protecting cells from death. In addition, autologous cell source to easily obtain from patients are promising candidates for cell therapy in cardiovascular field. Methods: mADSCs were confirmed stem cell properties and secreted cytokines were evaluated in vitro. Eighteen acute myocardial infarction (AMI) rats were divide into 3 group; sham (n=6), suspended mADSCs (n=6), and mADSCs sheet (n=6) groups. In the mADSCs sheet group, 60х106 cells were cultured for 2 days onto temperature-responsive polymers and the sheets were then transplanted over the infarct region. In additional, the sheet was made of carboxyfluorescein diacetate succinimidyl ester (CFDA) -labelled mADSCs to confirmed cell survival. Engraftment and differentiation were blindly assessed after 28 days. Results: The mADSCs expressed Sca-1+ and represented multi-differentiation potential. Interestingly, EGF and IGF levels significantly increased in the mADSCs sheet. Significant improvements in ejection fraction and fraction shortening value were observed in the mADSCs sheet and suspended mADSCs groups compared with the sham group at 14 and 28 days. But, it was not higher significance level in the mADSCs sheet group than in the suspended mADSCs group. Engraftment range and fibrosis area of infarct region were significantly higher in the mADSCs sheet group compared to the other two groups at 4, 14 and 28 days. In significant expressed cytokines (bFGF, IL-1a, IL-1ra, CT-1, EGF, TGFb1, IGF-1, IGF-2 and MCP-1) were observed in the mADSCs sheet group compared with the other 2 groups at 28 days after transplantation. In addition, in the mADSCs sheet was confirmed endothelial differentiation by Von Willebrand factor (vWF) at 4, 14 and 28 days. Conclusions: Transplantation of mADSCs sheet into rat infarcted myocardium increased engraftment and survival of transplanted cells. The mADSCs sheet is very useful for the study of stem cell proliferation and differentiation as well as for cell therapy in cardiovascular field.

Digital Impression taking for Maxillary Full-Arch Restoration with Immediate Loading. A Case Report.

2021 ◽  
Author(s):  
Jesús Peláez Rico ◽  
Jorge Cortés-Bretón Brinkmann ◽  
María Carrión Martín ◽  
Mabel Albanchez González ◽  
Celia Tobar Arribas ◽  
...  
Keyword(s):  
Acrylic Resin ◽  
Digital Impression ◽  
Immediate Loading ◽  
Clinical Report ◽  
Intraoral Scanner ◽  
Intraoral Scanning ◽  
Digital Impressions ◽  
Removable Prosthesis ◽  
And Function

The aim of this clinical report is to describe a maxillary full-arch implant supported restoration with immediate loading performed by means of an entirely digital workflow with photogrammetric system and intraoral scanning. A female patient with an edentulous maxillary arch attended the dental clinic seeking a maxillary fixed restoration. After treatment planning, six implants were placed using a surgical splint fabricated digitally by intraoral scanning of her previous removable prosthesis. Multi-unit abutments were fitted and two digital impressions were taken, one with a photogrammetric system for determining implant positions, and the other with an intraoral scanner for soft tissue registration. The acrylic resin structure of the immediate prosthesis was milled and placed within 8 hours of implant surgery. This provisional structure fitted correctly and provided adequate esthetics and function. Radiographic and clinical follow-up after 24 months observed adequate implant evolution.

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