Correlation of clinical performance with ‘in vitro tests’ of restorative dental materials that use polymer-based matrices

2012 ◽  
Vol 28 (1) ◽  
pp. 52-71 ◽  
Author(s):  
Stephen C. Bayne
Keyword(s):  
Clinical Performance ◽  
Dental Materials ◽  
In Vitro Tests ◽  
Restorative Dental Materials

scholarly journals Study of Surface Structure Changes for Selected Ceramics Used in the CAD/CAM System on the Degree of Microbial Colonization, In Vitro Tests

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Maciej Dobrzynski ◽  
Magdalena Pajaczkowska ◽  
Joanna Nowicka ◽  
Aleksander Jaworski ◽  
Piotr Kosior ◽  
...  
Keyword(s):  
Dental Materials ◽  
Lactobacillus Rhamnosus ◽  
Microbial Colonization ◽  
In Vitro Tests ◽  
Adhesive Properties ◽  
Structure Changes ◽  
Cad Cam ◽  
Biofilm Development ◽  
Made In

In the article has been presented an analysis of susceptibility of selected dental materials, made in the CAD/CAM technology. The morphology and structural properties of selected dental materials and their composites were determined by using XRPD (X-ray powder diffraction) techniques, as well as the IR (infrared) spectroscopy. Moreover, an adhesion as well as development of biofilm by oral microorganisms has been studied. It has been shown that a degree of the biofilm development on the tested dental materials depended on microorganism genus and species. Streptococcus mutans has demonstrated the best adhesion to the tested materials in comparison with Candida albicans and Lactobacillus rhamnosus. However, the sintered materials such as IPS e.max® and the polished IPS e.max® have showed the best “anti-adhesive properties” in relation to S. mutans and L. rhamnosus that have not formed the biofilm on the polished IPS e.max® sample. Furthermore, S. mutans have not formed the biofilm on both surfaces. On the contrary to S. mutans and L. rhamnosus, C. albicans has demonstrated the adhesive properties in relation to the above-mentioned surfaces. Moreover, in contrast to S. mutans and C. albicans, L. rhamnosus has not formed the biofilm on the polished IPS Empress material.

Research On Dental Amalgam: 1982-1986

1988 ◽  
Vol 2 (1) ◽  
pp. 71-82 ◽  
Author(s):  
D.B. Mahler
Keyword(s):  
Clinical Performance ◽  
High Sensitivity ◽  
Dental Amalgam ◽  
Performance Criterion ◽  
Dental Restoration ◽  
In Vitro Tests ◽  
Significant Finding ◽  
Amalgam Restorations

This paper is a five-year review of selected research papers on dental amalgam which were published during the years 1982 through 1986. Papers presented at scientific dental meetings are also included. During the past five years, clarification of amalgam metallurgy has been made, and a few innovative modifications have been recommended. The addition of palladium, indium, and selenium to dental amalgam has been suggested, but commercial applications have yet to be made. The mechanical property of creep has been studied more extensively, while the applicability of fracture toughness tests has been examined. More work has been done on the microleakage of amalgam restorations, with certain alloy factors showing an influence on this problem. Most in vitro investigations on the use of cavity varnish or resin films beneath amalgam restorations show reduced microleakage. Additionally, many electrochemical investigations were conducted. A most significant finding was that amalgam does not appear to break down in vivo as much as in vitro tests would indicate, the buffering action of saliva being protective in this regard. The marginal fracture evaluation of clinical amalgam restorations is still being used as a major clinical performance criterion, and measuring techniques for this failure mode have been improved. Measurements of metallic ion loss from amalgam were made with instruments of high sensitivity, but no evidence has been found to associate this loss with any disease entity. The rare presence of an allergy to mercury appears to be the only contra-indication for the use of amalgam as a dental restoration. Further research on dental amalgam can lead to improved clinical performance of this most useful restorative material.

scholarly journals Properties evaluation of silorane, low-shrinkage, non-flowable and flowable resin-based composites in dentistry

2015 ◽  
Author(s):  
Rodrigo Maia ◽  
Rodrigo S Reis ◽  
Andre FV Moro ◽  
Cesar Perez ◽  
Bárbara Pessôa ◽  
...  
Keyword(s):  
Filler Content ◽  
Important Determinant ◽  
Dental Materials ◽  
Dental Practice ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Knoop Microhardness ◽  
Properties Of Materials ◽  
Restorative Dental Materials

Purpose: This study tested the null hypothesis that different classes of direct restorative dental materials (silorane-based resin, low-shrinkage and conventional (non-flowable and flowable) resin-based composite (RBC)) do not differ from each other with regard to polymerization shrinkage, depth of cure, or microhardness. Methods: 140 RBC samples were fabricated and tested by one calibrated operator. Polymerization shrinkage was measured using a gas pycnometer both before and immediately after curing with 36 J/cm2 light energy density. Depth of cure was determined, using a penetrometer and the Knoop microhardness was tested from the top surface to a depth of 5 mm. Results: Considering polymerization shrinkage, the authors found significant differences (p<0,05) between different materials: non-flowable RBCs showed lower values, compared to flowable RBCs, with the silorane-based resin presenting the smallest shrinkage. The low shrinkage flowable composite performed similarly to non-flowable, with significant statistical differences compared to the two other flowable RBCs. Regarding to depth of cure, low-shrinkage flowable RBC were most effective compared to other groups. Microhardness was generally higher for the non-flowable vs. flowable RBCs (p<0.05). However, the values for low-shrinkage flowable did not differ significantly from those of non-flowable, but were significantly higher than those of the other flowable RBCs. Clinical Significance: RBCs have undergone many modifications as they have evolved and represent the most relevant restorative materials in today’s dental practice. This study of low-shrinkage RBCs, conventional RBCs (non-flowable and flowable) and silorane-based composite – by in vitro evaluation of volumetric shrinkage, depth of cure and microhardness – reveals that although filler content is an important determinant of polymerization shrinkage, it is not the only variable that affects properties of materials that were tested in this study.

scholarly journals Ageing of Dental Composites Based on Methacrylate Resins—A Critical Review of the Causes and Method of Assessment

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 882 ◽  
Author(s):  
Agata Szczesio-Wlodarczyk ◽  
Jerzy Sokolowski ◽  
Joanna Kleczewska ◽  
Kinga Bociong
Keyword(s):  
Clinical Performance ◽  
Dental Materials ◽  
Fatigue Tests ◽  
Dental Composite ◽  
Ageing Process ◽  
Inorganic Filler ◽  
Factors Affecting ◽  
Dental Resins ◽  
Oral Environment

The paper reviews the environmental factors affecting ageing processes, and the degradation of resins, filler, and the filler-matrix interface. It discusses the current methods of testing materials in vitro. A review of literature was conducted with the main sources being PubMed. ScienceDirect, Mendeley, and Google Scholar were used as other resources. Studies were selected based on relevance, with a preference given to recent research. The ageing process is an inherent element of the use of resin composites in the oral environment, which is very complex and changes dynamically. The hydrolysis of dental resins is accelerated by some substances (enzymes, acids). Bonds formed between coupling agent and inorganic filler are prone to hydrolysis. Methods for prediction of long-term behaviour are not included in composite standards. Given the very complex chemical composition of the oral environment, ageing tests based on water can only provide a limited view of the clinical performance of biomaterial. Systems that can reproduce dynamic changes in stress (thermal cycling, fatigue tests) are better able to mimic clinical conditions and could be extremely valuable in predicting dental composite clinical performance. It is essential to identify procedure to determine the ageing process of dental materials.

Preclinical Testing of Femoral Hip Components: An Experimental Investigation With Four Prostheses

2005 ◽  
Vol 127 (5) ◽  
pp. 872-880 ◽  
Author(s):  
John R. Britton ◽  
Patrick J. Prendergast
Keyword(s):  
Steady State ◽  
Femoral Component ◽  
Clinical Performance ◽  
Relative Displacement ◽  
In Vitro Tests ◽  
Preclinical Testing ◽  
Early Migration ◽  
Component Type ◽  
Comparable Performance

Existing standards for the preclinical testing of femoral hip implants have been successful in the objective of guaranteeing the implant’s fatigue strength. There is a need for an experimental test which could ensure prostheses were not susceptible to aseptic loosening. In this study we measure the relative movement between the prosthesis and the bone of four different cemented femoral component designs in in vitro tests. The aim is to determine if differences can be distinguished and whether the differences correlate with clinical performance. The four designs are the Charnley (DePuy International Ltd., UK), the Exeter (Stryker Osteonics Howmedica Corp., USA), the Lubinus SPII (Waldemar-Link GmbH, Germany), and the Müller Curved (JRI Ltd, UK). Five tests were carried out for each femoral component type, giving a total of 20 tests, and their permanent relative displacement (termed migration) and recoverable (i.e., elastic) relative displacement (termed inducible displacement) monitored over one million loading cycles. Considerable variation occurred in the tests. Nonetheless, most femoral components migrated medially, posteriorly, and distally. Most also rotated into varus. Translations of the Charnley (64microns) and Lubinus (67microns) implants were less than the Müller (72microns) and Exeter (94microns) implants, but this difference is not statistically significant. Most of the femoral components had rapid early migration followed by slower steady-state migration. With regard to the steady state inducible displacements of the prostheses, those of the Charnley, Exeter, and Lubinus decreased or were stable with respect to time, whilst those of the Müller typically increased with respect to time. It is concluded that migration is not a suitable basis for in vitro comparison of prosthesis designs. However, inducible displacement trends provide a clinically comparable performance ranking.

scholarly journals In Vitro Models for the Development of Peripheral Nerve Conduits, Part I: Design of a Fibrin Gel-Based Non-Contact Test

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3573
Author(s):  
Paola De Stefano ◽  
Angelica Silvia Federici ◽  
Lorenza Draghi
Keyword(s):  
Peripheral Nerve ◽  
Clinical Performance ◽  
In Vitro Models ◽  
In Vitro Tests ◽  
Neural Cells ◽  
Animal Testing ◽  
Fibrin Gel ◽  
Specific Implementation

Current clinical strategies to repair peripheral nerve injuries draw on different approaches depending on the extent of lost tissue. Nerve guidance conduits (NGCs) are considered to be a promising, off-the-shelf alternative to autografts when modest gaps need to be repaired. Unfortunately, to date, the implantation of an NGC prevents the sacrifice of a healthy nerve at the price of suboptimal clinical performance. Despite the significant number of materials and fabrication strategies proposed, an ideal combination has not been yet identified. Validation and comparison of NGCs ultimately requires in vivo animal testing due to the lack of alternative models, but in the spirit of the 3R principles, a reliable in vitro model for preliminary screening is highly desirable. Nevertheless, more traditional in vitro tests, and direct cell seeding on the material in particular, are not representative of the actual regeneration scenario. Thus, we have designed a very simple set-up in the attempt to appreciate the relevant features of NGCs through in vitro testing, and we have verified its applicability using electrospun NGCs. To this aim, neural cells were encapsulated in a loose fibrin gel and enclosed within the NGC membrane. Different thicknesses and porosity values of two popular polymers (namely gelatin and polycaprolactone) were compared. Results indicate that, with specific implementation, the system might represent a useful tool to characterize crucial NGC design aspects.

In Vitro Evaluation of Surface Roughness and Microhardness of Restorative Materials Submitted to Erosive Challenges

2011 ◽  
Vol 36 (4) ◽  
pp. 397-402 ◽  
Author(s):  
ALF Briso ◽  
LP Caruzo ◽  
APA Guedes ◽  
A Catelan ◽  
PH dos Santos
Keyword(s):  
Surface Roughness ◽  
Clinical Relevance ◽  
Dental Materials ◽  
Dental Erosion ◽  
In Vitro Evaluation ◽  
Acidic Solutions ◽  
Restorative Materials ◽  
Restorative Dental Materials ◽  
Surface Sealant

Clinical Relevance The effects of dental erosion caused by acidic solutions on the surface of restorative dental materials could be minimized by the application of a surface sealant.

scholarly journals Properties evaluation of silorane, low-shrinkage, non-flowable and flowable resin-based composites in dentistry

2015 ◽  
Author(s):  
Rodrigo Maia ◽  
Rodrigo S Reis ◽  
Andre FV Moro ◽  
Cesar Perez ◽  
Bárbara Pessôa ◽  
...  
Keyword(s):  
Filler Content ◽  
Important Determinant ◽  
Dental Materials ◽  
Dental Practice ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Knoop Microhardness ◽  
Properties Of Materials ◽  
Restorative Dental Materials

Purpose: This study tested the null hypothesis that different classes of direct restorative dental materials (silorane-based resin, low-shrinkage and conventional (non-flowable and flowable) resin-based composite (RBC)) do not differ from each other with regard to polymerization shrinkage, depth of cure, or microhardness. Methods: 140 RBC samples were fabricated and tested by one calibrated operator. Polymerization shrinkage was measured using a gas pycnometer both before and immediately after curing with 36 J/cm2 light energy density. Depth of cure was determined, using a penetrometer and the Knoop microhardness was tested from the top surface to a depth of 5 mm. Results: Considering polymerization shrinkage, the authors found significant differences (p<0,05) between different materials: non-flowable RBCs showed lower values, compared to flowable RBCs, with the silorane-based resin presenting the smallest shrinkage. The low shrinkage flowable composite performed similarly to non-flowable, with significant statistical differences compared to the two other flowable RBCs. Regarding to depth of cure, low-shrinkage flowable RBC were most effective compared to other groups. Microhardness was generally higher for the non-flowable vs. flowable RBCs (p<0.05). However, the values for low-shrinkage flowable did not differ significantly from those of non-flowable, but were significantly higher than those of the other flowable RBCs. Clinical Significance: RBCs have undergone many modifications as they have evolved and represent the most relevant restorative materials in today’s dental practice. This study of low-shrinkage RBCs, conventional RBCs (non-flowable and flowable) and silorane-based composite – by in vitro evaluation of volumetric shrinkage, depth of cure and microhardness – reveals that although filler content is an important determinant of polymerization shrinkage, it is not the only variable that affects properties of materials that were tested in this study.

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