Dynamic mechanical analysis of dental composite resins [Elektronische Ressource] / vorgelegt von Renata Vidal Mesquita

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• Gesundheit

Informations

• Publié par: eberhard_karls_universitat_tubingen
• Publié le: 01 janvier 2006
• Nombre de lectures: 32
• Poids de l'ouvrage: 2 Mo

Extrait

Aus der Universitätsklinik
Für Zahn-, Mund-, und Kieferheilkunde Tübingen
Abteilung Poliklinik für Zahnärztliche Prothetik mit Propädeutik
Ärztlicher Direktor: Professor Dr. H. Weber

Sektion für Medizinische Werkstoffkunde und Technologie
Leiter: Professor Dr. J. Geis-Gerstorfer





Dynamic mechanical analysis of
direct and indirect dental composite resins




Inaugural-Dissertation
zur Erlangung des Doktorgrades
der Zahnheilkunde
der medizinischen Fakultät
zu Tübingen


vorgelegt von
Renata Vidal Mesquita aus Natal/Brasilien
2006
































Dekan: Professor Dr. C. D. Claussen

1. Berichterstatter: Professor Dr. J. Geis-Gerstorfer
2. Berichterstatter: Prof. Dr. C. Löst
2









To my husband Adriano and
to my parents Vicente and Sônia.




















3Table of Contents

Dynamic mechanical analysis of direct and indirect dental composite resins…..1

1 Introduction…………..……………………………………………………………..8
1.1 Dental composite resins………………………………………………………. 8
1.1.1 Definition…………………………………………………………………..8
1.1.2 Main components………………………………………………………...8 3 Classification of resin composites………………………………………9
1.2 Elastic modulus………………………………………………………………..10
1.3 Elastic, viscous and visco-elastic materials………………………………...12
1.4 Static and dynamic tests……………………………………………………...13
1.5 Theory about Dynamic Mechanical Analysis (DMA)………………………14
1.6 DMA and dental polymeric materials………………………………………..16
1.7 Environmental challenge……………………………………………………..17
1.8 Objectives of this study……………………………………………………….18

2 Materials and methods……………………………………………….………….20
2.1 Materials………………………………………………………………………..20
2.1.1 Direct composites……………………………………………………….20
2.1.1.1 DiamondLite…………………………………………………….20 2.1.1.2 Grandio………………………………………………………….21
2.1.2 Indirect composites……………………………………………………..21
2.1.2.1 Artglass………………………………………………………….21
2.1.2.2 Vita Zeta LC…………………………………………………….22
2.2 Preparation of the samples…………………………………………………...22
2.3 Experimental groups…………………………………………………………..23
2.4 Storage medium……………………………………………………………….24
2.5 DMA Q800……………………………………………………………………...24
2.6 DMA calibration………………………………………………………………..25
2.7 Linear visco-elastic region……………………………………………………26
2.8 Poisson’s ratio…………………………………………………………………26
4 2.9 Glass transition temperature…………………………………………………27
2.10 Experimental method………………………………………………………..28
2.11 Frequency scan………………………………………………………………29
2.12 Thermal scan…………………………………………………………………30
2.13 Data analysis…………………………………………………………………30
2.14 Statistical analysis……………………………………………………………30
2.14.1 Frequency scan………..………………………………………………30
2.14.1.1 Comparisons between composites…………………………31 2.14.1.2 Individual results……………...………………………………32
2.14.2 Temperature scan………………………………………..……………33

3 Results………………………………………………………………...……………34
3.1 Frequency scan - Elastic modulus..…………………………………………34
3.1.1 Comparisons between composites (Analysis 1)……..……………...34
3.1.2 Comparisons between composites (Analysis 2 and 3)……………..34
3.1.3 Individual results (Analysis 4, 5 and 6)..……………………………...35
3.1.3.1 DiamondLite…………………………………………………….35
3.1.3.2 Grandio………………………………………………………….38
3.1.3.3 Artglass………………………………………………...............41
3.1.3.4 Vita Zeta LC…………………………………………………….44
3.2 Frequency scan - Viscous modulus……………………………..…………...47
3.2.1 Comparisons between composites (Analysis 1)…………………….47
3.2.2 Comparisons between composites (Analysis 2 and 3)………..……47
3.2.3 Individual results (Analysis 4, 5 and 6)……………………………….48
3.2.3.1 DiamondLite.........................................................................48
3.2.3.2 Grandio..............................................51 3.2.3.3 Artglass..............................................................54
3.2.3.4 Vita Zeta LC.......................................................57
3.3 Frequency scan - Loss tangent…….…………………………………………60
3.3.1 Comparisons between composites (Analysis 1)……….……………60
3.3.2 Comparisons between composites (Analysis 2 and 3)..……………60
3.3.3 Individual results (Analysis 4, 5 and 6)……………………………… 61
5 3.3.3.1 DiamondLite.........................................................................61
3.3.3.2 Grandio..............................................64 3.3.3.3 Artglass..............................................................67
3.3.3.4 Vita Zeta LC.......................................................70
3.4 Temperature scan - Elastic modulus (Analysis 7)…………………….…….73
3.4.1 DiamondLite…….........…………………………………………….......73
3.4.2 Grandio……...………….........…………………………………............73
3.4.3 Artglass……………………….........…………………………...............74
3.4.4 Vita Zeta LC……………………………..………………………...........74
3.4.5 Interpretation of the results..............................................................75
3.5 Temperature scan - Viscous modulus (Analysis 7)...………………...........76
3.5.1 DiamondLite….................................................................................76
3.5.2 Grandio............................................................................................76
3.5.3 Artglass............................................................................................77
3.5.4 Vita Zeta LC...............................77
3.5.5 Interpretation of the results..............................................................78
3.6 Temperature scan - Loss Tangent (Analysis 7).……………………………79
3.6.1 DiamondLite……………………………………………………….....…79
3.6.2 Grandio………………...…………………………………………..........80
3.6.3 Artglass…………………...………………………………………..........81
3.6.4 Vita Zeta LC………………...……………………………………..........82
3.6.5 Interpretation of the results..............................................................82
4 Discussions…………………………………………………………………….....84
4.1 Frequency scan………………………………………………………………..84
4.1.1 Comparisons between composites……………………………………84
4.1.2 Influence of storage conditions………………..………………………88
4.1.2.1 Water sorption and material loss……………………………..89
4.1.2.2 Post-curing……………………………………………………...92
4.1.3 Influence of testing conditions…………………………………………99
4.1.3.1 Frequency………………………………………………………99
4.1.3.2 Temperature…………………………………………………..104
4.2 Temperature scan……………………………………………………………108
6 4.2.1 Undercured experimental groups……………………………………109
4.2.2 Fully cured experimental groups…………………………………….112

5 Conclusions…………….……………………………………………………….117

6 References………………………………………..……………………………...119

7 Acknowledgements…………………………………………………………….127

8 Curriculum vitae…………………………………………………………………128



















71 Introduction

1.1 Dental composite resins

1.1.1 Definition
Dental composite resins are complex, tooth-coloured filling materials composed
of synthetic polymers, particulate ceramic reinforcing fillers, molecules which
promote or modify the polymerization reaction that produces the cross-linked
polymer matrix from the dimethacrylate resin monomers, silane coupling agents
which enhance the adhesion of the reinforcing fillers to the polymer matrix (1),
and other minor additions including polymerization inhibitors, stabilizers and
colouring pigments.

1.1.2 Main components
- Organic resin matrix: Many of today’s commercially available dental resin
composite materials utilize Bisphenol-A-glycidyl dimethacrylate (BisGMA) or
Urethane dimethacrylate (UDMA) as major monomer (2).
The BisGMA is the reaction product of Bisphenol-A and glycidyl ester
methacrylate (GMA). This bulky bifunctional monomer has a high reactivity, high
molecular weight, undergoes low polymerization shrinkage, and produces a
cross-linked, three-dimensional resin network (3). Its main disadvantage
remains the high viscosity attributed to