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1

Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

Żmudzki J., Malara P., Chladek G.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2A

843--846

EN

Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

2

The influence of silver nanoparticles introduced into RTV-silicone matrix on the activity against Streptococcus mutans

Chladek G., Mertas A., Krawczyk C., Stencel R., Jabłońska-Stencel E.

Archives of Materials Science and Engineering

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2016

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Vol. 78, nr 2

59--65

EN

Purpose: The silicone based room temperature vulcanized (RTV) polymers are commonly used materials for medicine, especially for dentures and maxillofacial prostheses. Unfortunately, the colonization of those materials by pathogenic microorganisms is wellknown problem related with their applications. The aim of presented study was to examine antibacterial properties of RTV silicone for dentistry modified with silver nanoparticles. Design/methodology/approach: The silver nanoparticles were introduced into twocomponent system silicone based materials. The presence of silver nanoparticles was investigated with scanning electron microscope (SEM). The antibacterial activity against Streptococcus mutans was determined. The result were statistically analysed with a Statistica 12.5 software and non-parametric Kruskal-Wallis test (α = 0.05). Findings: The silver nanoparticles introduction into RTV - silicone allowed to enhance the antimicrobial resistance against standard strain of Streptococcus mutans. Research limitations/implications: In this research only Streptococcus mutans bacterium strain was used. In future activity of presented materials against other pathogenic bacteria living in oral cavity should be determined. Additionally long term investigation should be prepared. Practical implications: The colonization of dental materials with pathogenic bacteria and fungus is one of the most important and still unresolved problems related to exposition on oral environment. The low microbiological resistance of RTV-silicones and antimicrobial potential of silver were reported in numerous studies. The gram-positive Streptococcus mutans is commonly found in the human oral cavity and it is an important factor to tooth decay. Originality/value: The resistance against Streptococcus mutans of modified material was enhanced. The investigated materials could be a potential factor a potential conducive to reducing the risk of oral cavity infections.

3

Wpływ metakrylanu metylu na wytrzymałość połączenia płyty protezy z zębami akrylowymi

Nowak W., Karońska K., Pryliński M., Frączak B. A., Prylińska-Czyżewska A.

Przemysł Chemiczny

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2015

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T. 94, nr 1

98-99

PL

Określono wpływ metakrylanu metylu na wytrzymałość połączenia sztucznych zębów akrylanowych z tworzywem płyty protezy. Badania wykazały, że monomer zaaplikowany na powierzchnię zęba sztucznego przed przeprowadzonym procesem polimeryzacji przyczynia się do zwiększenia wytrzymałości połączenia pomiędzy analizowanymi materiałami.

EN

Me metacrylate was applied onto an artificial acrylic teeth base attached then to denture base and polymerized at 50°C and 4 bar for 15 min. The bonds were studied for shearing strength and fracture type. The application of Me metacrylate resulted in threefold increase in the shearing strength value and a small decrease in no. of adhesive fractures.

4

Effect of silica filler on properties of PMMA resin

Chladek G., Żmudzki J., Basa K., Pater A., Krawczyk C., Pakieła W.

Archives of Materials Science and Engineering

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2015

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Vol. 71, nr 2

63--72

EN

Purpose: Of this paper was to investigate the effect of silica nanofiller addition to PMMA-based denture material. The null hypothesis was that no difference exists between the mean flexural strength, hardness, sorption among materials without and with different content of silica filler. Design/methodology/approach: The nanosilica was introduced into “powder” component of commercially available PMMA resin for dentistry in concentrations 2, 5 and 10%. The SEM observations were made to confirm dispersion quality. To confirm presence of silica filler the X-ray microanalysis have been made. The influence of nanosilica addition on flexural strength, flexural modulus, hardness and sorption were investigated. Samples were stored at distilled water and ethanol solution. Statistical analysis were prepared with the one-way or the two-way analysis of variance ANOVA ( α =0.05), and Newman-Keuls significant difference post hoc test was used to determine the differences between mean values ( α =0.05). Findings: The result show that all investigated properties were changed after silica filler addition. Initially flexural strength decreased, but after accelerated again in ethanol incised. Flexural modulus and hardness increased. Sorption was decreased in both aging liquids. Research limitations/implications: Limitations resulting from the specificity of the conditions of laboratory tests and aging conditions so it does not allow to fully translate obtained results to expected results of clinical trials. Practical implications: The PMMA drawback is still insufficient mechanical properties, so it can be easily damaged during an accidents or when a patients applies high mastication force to the denture which show areas for further mechanical properties improvement. One of the ways of improving the mechanical properties of PMMA based materials may be nanoparticle addition, including commonly used nanosilica fillers. Originality/value: Influence of destructive plasticizing solutions on chosen properties of materials with different concentrations of silica fillers have been investigated.

5

The method of evaluation of the abilities of the lining soft materials to relieve the mucous membran

Chladek G., Żmudzki J., Malara P.

Archives of Materials Science and Engineering

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2013

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Vol. 64, nr 2

125--134

EN

Purpose: The presentation of a simple method of evaluation of the effectiveness to relieve the mucous membrane under thednture through soft lining materials, which is based on the analysis of creep curves and energy dissipated by the samples during the cyclic compression. Design/methodology/approach: On the testing machine there were conducted studies of time characteristics and there was determined the energy dissipated by the samples during the cyclic compression. The results were subjected to the analysis of variation ANOVA (α=0.05) with the Newman-Keuls post-hoc test. Findings: The presented method allowed to conduct the evaluation of abilities to relieve the mucous membrane of soft lining materials significantly different in hardness. The studies showed that the softer materials characterised with a greater ability to dissipate energy, nevertheless, after taking the load off, the return to the original form in case of materials with the lowest hardness lasted much longer. The samples of softer materials with large values of stress underwent much greater stiffening, Research limitations/implications: Limitations not allow the full translation of the obtained results into the expected results of clinical trials. The demonstrated relations between the behaviour of the samples and the hardness of materials are proper for the tested materials, but not necessarily for other materials of a similar hardness. Practical implications: The presented methodology of the research is even closer to the expected clinical reality, when the alveolar ridge is more uniform and flat, but in order to obtain an even fuller image of the situation in case of uneven or sharp alveolar ridges, one should conduct additional tests with the method consisting of the load of the samples with a properly shaped penetrator. Originality/value: The advantages of the presented methods are: the possibility for a quantitative use of the comparison of energy dissipated by the samples and the estimation of the material reaction while maintaining the possibility to use the tests of variable values of stresses, what enables an easy association of the obtained results with the values of stresses, which cause pain sensations in the mucous.

6

Badania modelowe rozkładu naprężeń kontaktowych na powierzchni błony śluzowej pod protezami zębowymi metodą elementów skończonych

Żmudzki J.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2011

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Vol. 17, nr 3

235-238

PL

Użytkownicy konwencjonalnych protez zębowych osiadających często cierpią z powodu urazów tkanek miękkich i bólu. Mechanizmy oddziaływania pomiędzy twardymi siodłami protez a powierzchnią błony śluzowej, które decydują o biomechanice protezy, są słabo poznane, szczególnie w warunkach obciążeń zgryzowych odpowiadających realnym funkcjom żucia. W pracy przedstawiono numeryczne trójwymiarowe badania symulacyjne MES (Metoda Elementów Skończonych), w których uwzględniono możliwość odrywania protezy oraz przesuwu z tarciem na powierzchni błony śluzowej. W obliczeniach kontaktu zastosowano rozszerzone sformułowanie mnożników Lagrange'a z implementacją klasycznego liniowego modelu tarcia. Przyjęto warunki obciążenia protezy z uwzględnieniem działania skośnych sił zgryzowych oraz założono możliwość zaistnienia kontaktu zwarciowego z protezą górną po stronie balansującej. Zastosowana metodyka badań modelowych pozwoliła na rozpoznanie zjawisk towarzyszących przeciwdziałaniu destabilizacji dolnej protezy poprzez kontakty zwarciowe po stronie balansującej.

EN

The users of conventional dental prostheses, commonly suffer from pain and injuries. The interaction mechanisms between hard denture saddles and mucous membrane surface, which decide on denture biomechanics, are not deeply understood, especially under the conditions of occlusal loads reflecting real mastication functions. In this paper, 3D numerical FEM (Finite Element Method) simulation, in which the possibility of detaching denture and slipping with friction on the surface of mucous membrane, is presented. In calculations, the multiplier Lagrangian formulation with implemented classical linear friction model, was exploited. It was assumed that the denture loading i s the oblique occlusal force. The possible occurrence of occlusal contact with upper denture at the balancing side, was considered, as well. The presented model analysis enabled to determine phenomena counteracting destabilization of the lower denture, by means of occlusal contacts at the balancing side.

7

Can typical overdentures attachments prevent from bone overloading around mini-implants?

Żmudzki J.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 2

542--551

EN

Purpose: High level of successful maintenance of implants located in anterior part of mandible popularizes economical solutions of implant-retained soft tissue supported dentures including those using narrow mini-implants with small diameter - of 1.8-2.2 mm. Design/methodology/approach: FEM modeling analyses were used to determine distribution of mastication loads between mucous foundation and bone tissue surrounding mini-implants that have 1.8 mm diameter. Examined were two types of commercial solitary denture attachments, described as biomechanically compatible due to their rotational movements freedom or due to the additional pivoting mobility. Findings: In case of both types of attachments the most dangerous lateral implants loadings significantly exceed half of oblique mastication loads value. In mini-implants and bone tissue lateral forces generate a high level of stresses. Research limitations/implications: Analyses were carried out with assumed linear characteristics of materials. Denture-to-soft foundation, as well as implant-to-bone complete adherence was assumed. Practical implications: While using mini-implants it is crucial to carefully evaluate the condition of bone foundation, due to the risk of quick development of atrophic processes in case of insufficient bone parameters. In case of mini-implants very important is very high strength value level and surface quality, due to the fact that in case of diameter of 1.8mm there might occur local yielding and propagation of fatigue cracks. Originality/value: Commercial types of attachments do not deserve the name of mechanically biocompatible, as they do not allow for such significant reduction of overloading effects, as the non-commercial silicone attachments.

8

Badania doświadczalne oddziaływania protezy szkieletowej na zęby oporowe

Gralewski J., Grądzki R., Wojciechowski J., Bogusławski G.

Aktualne Problemy Biomechaniki

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2010

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z. 4

51--58

PL

W pracy przedstawiono wyniki badań doświadczalnych pomiarów sił rekcji w zębach oporowych w odniesieniu do sił żucia działających na protezę. Na specjalnie skonstruowanym stanowisku badawczym złożonym z układu obciążającego tensometrycznego przetwornika siły poddano obciążeniu wybraną protezę i dokonano pomiaru sił przenoszonych przez zęby oporowe. Zastosowano dwa schematy obciążenia w dwóch wybranych miejscach na powierzchniach żujących uzupełnionych zębów w bliskim sąsiedztwie zęba oporowego. Analiza stanu obciążenia pozwoliła zmierzyć wartości sił reakcji pionowych oraz ocenić kierunki sił poziomych działających na zęby filarowe.

EN

The experimental studies of measuring of reaction forces on abutment teeth relative to mastication forces acting on a removable partial denture were carried out. A specially constructed experimental system consists of stand and strain gauges equipment, In this system loading was applied to a selected denture and forces transmitted by abutment teeth were measured. Two loads were applied in two selected places on the masticatory surfaces of denture teeth adjacent to the abutment teeth. The results of the study are presented in a table. The analysis of the load allowed to measure values of vertical reaction forces and to make conclucion about directions of horizontal forces acting on abutment teeth.

9

The evaluation of selected attachment systems for implant-retained overdenture based on retention characteristics analysis

Chladek G., Wrzuś-Wieliński M.

Acta of Bioengineering and Biomechanics

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2010

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Vol. 12, no. 3

75-83

EN

The results of mechanical characteristics of attachments used for retaining and stabilizing overdenture have been analysed. Two commercially used attachments (a ball attachment and a bar attachment) and elastic frictional attachments designed by the research team with Professor Chladek as the leader have been investigated. The diagrams of force–displacement characteristics have been registered. Retention forces (FR) have been determined and total work (WT) disconnecting the attachments has been calculated on the basis of these diagrams. The analysis of total work corresponding to different types of attachments made it possible to distinguish some characteristic areas which illustrate specific features of particular designs. It has been revealed that determining the retention force allows us to compare only the attachments which work on similar bases. In order to conduct a purely objective comparison of the efficiency of different designs, it is necessary to analyze complete force–displacement characteristics as well as to determine on this basis the subsequent phases of separating the parts of attachments and to find the value of the work which in fact determines their quality. The comparison of selected commercially used designs and the presented elastic frictional attachments (taking into account the criterion of work) gives clear evidence that the introduced design of attachment enables us to create very good conditions of retaining overdenture.

10

Overlay dentures - constructional and research aspects

Jałbrzykowski M., Mystkowska J.

Acta Mechanica et Automatica

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2010

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Vol. 4, no. 4

29-35

EN

The paper presents selected issues relating to movable dentures with their general characteristics of fixings. Reference was made to the most importantmaterial-constructional aspects and the problems that arise with this type of solutions. In the work the method of durability and reliability evaluation and selection of materials for the kinematics connections of this type of structure was proposed.

11

Elastic silicone matrices as a tool for load relief in overdenture implants

Żmudzki J., Chladek W.

Acta of Bioengineering and Biomechanics

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2008

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Vol. 10, nr 4

7-14

EN

The objective of this study was to analyze how the elasticity of matrices attaching to an overdenture affects implants and how the location of implants affects their loading. The attachments proposed made from elastic matrix increase the denture stability and simultaneously preserve the mechanisms of occlusion load transfer in compliance with principles usually applied in the denture used in the case of edentulous maxilla or mandible. It was revealed that denture dislodgement caused by occlusion forces did not result in the force being greater than the attachment retention force determined empirically. Our analysis also demonstrates that in the case where the implants are inserted in such a way that they are shifted too much to the back area of the tooth arc, an increase in the implant bending occurs, with the supporting capacities of alveolar processes not being fully utilized. This fact suggests the necessity to increase the susceptibility of attachments in a posterior location.