A Collection of Scientific Results. Filtek. Silorane. Low Shrink Posterior Restorative. Study Booklet

Transcription

1 A Collection of Scientific Results Low Shrink Posterior Restorative Study Booklet

2 Introduction Composite materials have been used in dental practices to restore teeth since the pioneering work of R. L. Bowen and the introduction of composites to the dental market by 3M in the early 1960s. Significant improvements have been made since then. Composites are an essential part of today s dentistry due to their versatile clinical use and high esthetics that allow the creation of virtually invisible restorations. It is striking that, over the years, polymerization shrinkage has been only incrementally reduced, and remains as one of the major drawbacks of composite materials. Shrinkage during curing results in stress which challenges the tooth/composite interface. Previously, the main strategy to reduce shrinkage focused on increasing the filler loading. Significant improvements in filler technology have been achieved using nanotechnology which was introduced in 3M ESPE s Supreme Universal Restorative product. However, shrinkage remains an intrinsic property of the methacrylate resin matrix which results in a dimensional change during polymerization. We are very excited to introduce Low Shrink Posterior Restorative which uses a non-methacrylate resin matrix to realize a fundamental improvement in cure shrinkage. resin is based on a new silorane chemistry comprised of ring-opening monomers that provide for low polymerization shrinkage. The new silorane system provides a direct solution to the longstanding customer need for low shrinkage. During the development of the System researchers worldwide evaluated this break-through technology in numerous studies. More than 40 high quality studies have been performed proving s excellent material properties, clinical performance and supporting its biocompatibility. Clinical studies continue to be carried out to investigate the long-term behavior. Dr. Alfred Viehbeck Global Technical Director 3M ESPE 2

3 Table of Contents Section Page 1. Introduction 4 2. Shrinkage and Stress Tooth Deformation Adhesion and Marginal Quality Mechanical / Physical Properties Biocompatibility and Bacterial Adhesion Clinical Studies 55 3

4 1. Introduction 1 Rationale Polymerization shrinkage and the resulting shrinkage stress, lead to microleakage which is among the major factors for composite material failures in the oral environment. Moreover, shrinkage stress can lead to tooth deformation, enamel cracks and stress-induced post-operative sensitivity (Figure 1). Materials which remain dimensionally stable upon polymerization, coupled with an advanced bonding to the enamel and dentin, will markedly enhance the stability of the restoration under functional stress. Low Shrink Posterior Restorative is designed to minimize shrinkage and polymerization stress. microleakage secondary caries enamel micro-cracks marginal staining adaptation post-operative sensitivity Figure 1: Clinical challenges associated with high shrinkage and polymerization stress. 4

5 1. Introduction Chemistry of the Resin System The chemistry of dental restorative composites started in the late 1940s. Since then many technological developments have significantly improved the clinical performance of dental resin composites. However, the com-mon chemical basis for all restorative composites remained the radical polymerization of methacrylates or acrylates and nowadays composites practically all employ dimethacrylates such as TEGDMA, UDMA or Bis-GMA. The low-shrinking Low Shrink Posterior Restorative is based on the new ring-opening chemistry (Figure 2) which is a totally new class of compounds for use in dentistry. 1 Siloxane Oxirane Figure 2: chemistry. Outlined in detail by Weinmann et al. (2005) in a study cited on page 11, the name derives from its chemical building blocks siloxanes and oxiranes. Siloxanes are well known in industrial applications for their distinct hydrophobicity. By incorporating the siloxanes into the dental resin, this favorable property was transferred to the composite. Oxiranes have been used for a very long time in many technical fields, especially where high forces and a challenging physical environment are expected, such as in the manufacture of sports equipment like tennis rackets or skis, or in the automotive and aviation industries. The oxirane polymers are known for their low shrinkage and the outstanding stability toward many physical and chemophysical forces and influences. The combination of the two chemical building blocks of siloxanes and oxiranes provides the biocompatible, hydrophobic and low-shrinking base of Low Shrink Posterior Restorative. This innovative resin matrix represents the major difference of Low Shrink Posterior Restorative compared to conventional methacrylates. Also, the initiating system and the filler were adapted in order to provide the best performance of the new technology. The System (bond, primer, restorative) was thoroughly 5

6 1. Introduction 1 evaluated for its biocompatibility and was found to be safe for its intended use.we used industry standards and internationally- accepted guidelines to conduct our biocompatibility assessment on both the finished product and its ingredients. The assessment included a series of tests and a review of published toxicity literature on ingredients, in addition to characterization of product materials and performance. The biocompatibility of was confirmed by a variety of external studies. Some key studies you will find summarized in the section Biocompatibility and Bacterial Adhesion of this booklet. Figure 3: Composition of Low Shrink Posterior Restorative. Ring-Opening Polymerization Figure 4 illustrates the reactive groups of the monomers for both methacrylates and siloranes. The polymerization process of methacrylate-based resins occurs via radical addition reaction of their double bonds, which results in higher polymerization contraction compared to the cationic ring-opening polymerization of the siloranes. The ring-opening step in the polymerization of the silorane resin compensates a significant amount of the polymerization shrinkage which occurs in the curing process. The reduced amount of shrinkage is illustrated schematically in Figure 4. During the polymerization process of methacrylates, molecules have to approach their neighbors to form chemical bonds. This process results in a loss of volume, namely polymerization shrinkage. In contrast to the linear-reactive groups of methacrylates, the ring-opening chemistry of the s starts with the cleavage and opening of the ring systems. This process gains space and counteracts the loss of volume which occurs in the subsequent step, when the chemical bonds are formed. In total, the ring-opening polymerization process yields a reduced volumetric shrinkage. 6

7 1. Introduction Oxirane 1 Volumetric Shrinkage < 1% 1 Methacrylate Methacrylate Volumetric Shrinkage Figure 4: Reactive sites of and methacrylates and corresponding shrinkage reduction upon polymerization. Besides shrinkage, another parameter of paramount importance to the performance of a restorative material is polymerization stress. Polymerization stress is generated when composites are cured in the bonded state and the polymerization shrinkage develops forces within the cavity walls. The rigid tooth structure will withstand these forces to a certain degree, however, these tensions can lead to marginal gaps or to damage of healthy tooth structure by its deformation. These forces or tensions are summarized under the term polymerization stress. technology was developed to minimize shrinkage and for low stress development. The kinetics of the initiation and polymerization of the resin were optimized to provide very low polymerization stress. The minimal shrinkage and polymerization stress were evaluated extensively as reflected in the many studies on shrinkage and stress provided in this study booklet. The uniqueness of Low Shrink Posterior Restorative is nicely visualized for example by Prof. Watts in the study Correlation of Shrinkage and Shrinkage Stress (page 10). Prof. Bouillaguet modeled the impact of shrinkage stress on the tooth with a very sophisticated method that measures the movement of the cusps towards each other while the resin cures in the cavity (page 24). 7

8 1. Introduction 1 At the same time Low Shrink Posterior Restorative provides mechanical properties expected from a state-of-the art composite in terms e. g. flexural strength or E-modulus. Moreover, based on the network which is more hydrophic than that of methacrylates exhibits a very low water uptake and proved to be very stable against chemical challenges representive of the diet. Many studies illustrating these favorable properties can be found in the chapter Mechanical Properties in this study booklet. Initiator System One component of the initiating system is the well established camphor quinone, which matches the light spectrum of Halogen and LED dental polymerization light sources. Unique components of the initiating system are iodonium salts and electron donors, which generate the reactive cationic species that start the ring-opening poly merization process. Figure 5: Initiation chemistry for s. The initiating system of Low Shrink Posterior Restorative was tailored so that the resulting polymerization kinetics leads to a minimized polymeri zation stress but provides another major advantage: it allows the practitioner to work longer under full operatory light than with any conventional methacrylate-based composite which is illustrated impressively by a study on page 46. Filler Technology Low Shrink Posterior Restorative is filled with a combination of fine quartz particle and radiopaque yttrium fluoride. From the filler side, restorative is classified as a microhybrid composite. The quartz surface is modified with a silane layer which was especially adopted to the technology in order to provide the proper interface of the filler to the resin for long-term, excellent mechanical properties. 8

9 1. Introduction System Adhesive the one and only adhesive system for Low Shrink Posterior Restorative 1 System Adhesive has been specially designed to provide strong and long-lasting bonding of Low Shrink Posterior Restorative to enamel and dentin, providing the basis for excellent marginal integrity of the restorations. is more hydrophobic than conventional methacrylate resins. That means the System Adhesive has to bridge a larger gap between the hydrophilic tooth substrate and the hydrophobic silorane material. Therefore, System Adhesive has been designed as a two-step adhesive: System Adhesive Self-Etch Primer is methacrylate-based and rather hydrophilic for good wetting of the tooth which provides the basis for strong and durable adhesion to the tooth. System Adhesive Bond is also methacrylate-based and optimized for wetting and adhering to the hydrophobic Low Shrink Posterior Restorative. Chemical bonding between Self-Etch Adhesive and Low Shrink Posterior Restorative is ensured by hybrid molecules that can react with both methacrylates in the adhesive and the s in the restorative. These hybrid molecules are crucial for achieving high bond strength with the composite. Due to the unique chemistry of it may only be used with its dedicated System Adhesive. Acidic Monomer of System Adhesive Bond Oxirane Group Curing of Adhesive Application and Curing of Restorative Chemical Bond between Adhesive and Composite Figure 6: Mechanism of chemical bonding between System Adhesive Bond and Low Shrink Posterior Restorative. 9

10 2. Shrinkage and Stress Volumetric Shrinkage and Polymerization Stress 2 Title: Correlation of Volumetric Shrinkage and Shrinkage Stress for Dental Composites Executed by: D. C. Watts, University of Manchester, UK Unpublished data Aim of the study: Shrinkage stress during polymerization of dental composites can lead to marginal gaps, tooth deformation, enamel cracks and even tooth hypersensitivity. The aim of this study was to characterize the development of volumetric shrinkage and shrinkage stress for in comparison to methacrylate based composites. Results: Low Shrink Posterior Restorative revealed significantly lower volumetric shrinkage and polymerization shrinkage stress values than the methacrylate based composites tested. Shrinkage Stress (Bioman method) and Polymerization Shrinkage (Bonded Disc Method) 9 Stress [MPa] Tetric EvoCeram EsthetX Venus TPH 3 CeramX Herculite XRV Premise ELS P60 XtraFil Grandio Quixfil Estelite Sigma Shrinkage [%] 10

11 2. Shrinkage and Stress Polymerization Shrinkage Title: s in dental composites Published by: W. Weinmann, C. Thalacker and R. Guggenberger, 3M ESPE, Seefeld, Germany Published in: Dental Materials (2005) 21, Aim of the study: The purpose of this study was to compare the product profile of a -based composite which polymerizes by a cationic ring opening process with the product profile of different methacrylate based restoratives. Results: The composite revealed with 0.94 vol% (bonded disc method) and 0.99 vol% (Archimedes method) the lowest polymerization shrinkage among all composites tested. Its reactivity was comparable to the reactivity of Tetric Ceram. However, the ambient light stability of >10 min for was higher than the ambient light reactivity of the other tested methacrylates (55 90 s). The ring opening chemistry of the s enables for the first time shrinkage values lower than 1 vol% and mechanical parameters as E-Modulus and flexural strength comparable to those of clinically well accepted methacrylate based composites. 2 Archimedes shrinkage [%] Correlation of Polymerization Shrinkage (Bonded Disc Method and Archimedes Method) QuiXfil Aelite LS Tetric Ceram Z Bonded disc shrinkage [%] Solitaire 2 Spectrum TPH Note: The study summarized on page 46 shows that provides up to 9 min working time under operatory light illumination (ISO 4049) 11

12 2. Shrinkage and Stress Polymerization Shrinkage 2 Title: Determination of Volumetric Shrinkage by means of a Video Imaging Method (AccuVol) Executed by: J. Burgess, USA Unpublished data Aim of the study: This study compared the volumetric shrinkage of with methacrylate-based composites by means of a video imaging method (AccuVol). Results: Low Shrink Posterior Restorative revealed significantly lower polymerization shrinkage values than the methacrylate-based composites. Polymerization Shrinkage (AccuVol Method) Shrinkage [Vol %] Heliomolar Z250 Sure Fil Z100 Herculite XRV Venus EsthetX Renamel Miris Dentin Point 4 12

13 2. Shrinkage and Stress Polymerization Shrinkage Title: Parameters Influencing the Shrinkage Determination by Mercury Dilatometry Published by: G. Rackelmann, W. Weinmann, J. Hansen and A. Anderski 3M ESPE AG, Seefeld, Germany Published at: IADR 2006, Brisbane, Australia, Abstract #2461 Aim of the study: Polymerization shrinkage can be measured by mercury dilatometry. This study investigates the influence of sample weight and recording time on the shrinkage values as determined by mercury dilatometry. Results: Shrinkage determination by mercury dilato metry is highly dependent on sample weight and recording time. Lower sample sizes result in higher shrinkage values. Even the 500 mg samples are very likely too small which results in unrealistic high shrinkage values. Recording time should be at least 12 h. revealed the lowest shrinkage within all sample weights, whereas QuiXfil and Z250 showed the same higher shrinkage values. Low Shrink Posterior Restorative revealed the lowest within all sample weights and reaches its final shrinkage earlier than Z Absolute volumetric shrinkage [%] Relative shrinkage (24 h = 100%) [%] Sample weight and shrinkage (Mercury Dilatometry) mg 300 mg mg Recording time and relative shrinkage (Mercury Dilatometry) Z Z time [h] 13

14 2. Shrinkage and Stress Polymerization Shrinkage 2 Title: Volumetric Shrinkage of Low Shrinkage Composite Resins Published by: T. M. Palmer, T. F. Gessel, C.C. Christensen, S. J. Melonakos, and B. J. Ploeger, Clinical Research Associates, Provo, UT, USA Published at: IADR 2005, Baltimore, USA, Abstract #0296 Aim of the study: Compare volumetric shrinkage of conventional composite resins and an experimental silorane resin using mercury dilatometry. Results: Low Shrink Posterior Restorative exhibited the lowest shrinkage of all materials tested. Volumetric Shrinkage (Mercury Dilatometry) Shrinkage [%] Nulite Heliomolar Estelite Sigma Aelite ELS Supreme Herculite XRV Spectrum TPH Tetric Ceram 14

15 2. Shrinkage and Stress Polymerization Shrinkage Title: Historical Evolution of Volumetric Polymerization Shrinkage of Restorative Composites Published by R. Guggenberger, W. Weinmann, O. Kappler, J. Fundingsland, and C. Thalacker, 3M ESPE AG, Seefeld, Germany Published at: IADR 2007, New Orleans, USA, Abstract #0403 Aim of the study: The purpose of this study was to determine the polymerization shrinkage of filling materials and analyze the importance of this shrinkage to dentistry. Therefore, volumetric shrinkage was determined (Archimedes method) for composites introduced since Results: The development over the last decade reveals that the manufacturers are working on low shrink composites. However, only a slight decrease was achieved (average decrease 0.05 %/year), because methacrylates as the chemical basis for all available composites remained unchanged. In contrast Low Shrink Posterior Restorative with its ring opening poly merization monomer enables significant shrinkage reduction. 2 Material Manufacturer Shrinkage [%] (Deviation)* Year of Introduction Herculite XRV Kerr 2.78(0.10)ef 1993 Tetric Ceram Ivoclar-Vivadent 2.98(0.08)fg 1996 Spectrum TPH Dentsply 3.49(0.47)h 1996 Solitaire Heraeus-Kulzer 3.71(0.09)h 1997 SureFil Dentsply 2.36(0.05)bcde 1998 Definite Degussa/Dentsply 2.45(0.19)cde 1998 Alert Jeneric Pentron 2.48(0.16)cde 1998 Prodigy Condensable Kerr 2.54(0.15)de 1998 P60 3M ESPE 2.13(0.13)abcd 1999 Z250 3M ESPE 2.14(0.04)abcd 1999 In-TenS Ivoclar-Vivadent 2.14(0.02)abcd 2001 Aelite LS Bisco 2.29(0.23)bcd 2002 Supreme 3M ESPE 2.32(0.03)bcd 2002 Venus Heraeus-Kulzer 3.05(0.06)fg 2002 EsthetX Dentsply 3.37(0.26)gh 2002 Grandio VOCO 2.10(0.23)abc 2003 QuiXfil Dentsply 2.12(0.13)abcd 2003 ELS (Extra Low Shrinkage) Saremco 2.39(0.32)bcde 2003 Solitaire 2 Heraeus-Kulzer 3.64(0.05)h 2003 Premise Kerr 1.80(0.22)a 2004 TPH3 Kerr 3.48(0.32)h 2004 Tetric EvoCeram Ivoclar-Vivadent 2.03(0.02)ab M ESPE 0.99(0.07) future * Volumetric shrinkage as determined by the Archimedes method. Identical superscript letter indicate no statistical difference. 15

16 2. Shrinkage and Stress Polymerization Stress 2 Title: Polymerization Contraction Stress of and Metha crylate-based Composites. Executed by: T. DeGee and A. Feilzer, University of Amsterdam (ACTA), The Netherlands Unpublished data Aim of the study: Contraction stress during polymerization of dental composites can lead to marginal gaps, tooth deformation, enamel cracks or even hypersensitivity. This study determined the polymerization shrinkage stress of and methacrylate based composites by means of a tensilometer. In this device the composite samples are bonded between a glass and a metal plate. During polymerization the shrinkage stress is recorded over time by a load cell connected to the metal plate. Results: Low Shrink Posterior Restorative revealed significantly lower polymerization shrinkage stress than the methacrylate composites tested. Polymerization Stress (Tensilometer Method) Stress [MPa] Quixfil Spectrum TPH Tetric Ceram Z250 Supreme Time [sec] 16

17 2. Shrinkage and Stress Polymerization Stress Title: Determination of polymerization shrinkage stress by means of a photoelastic investigation. Published by: C. P. Ernst, G. R. Meyer, K. Klocker and B. Willershausen, University of Mainz, Germany. Published in: Dent Mat 2004;20(4): Aim of the study: This study examined the polymerization stress of different established and experimental composite resins which have been claimed to exhibit less polymerization shrinkage by means of a photo-elastic investigation. Results: After 4 min and 24 h Low Shrink Posterior Restorative showed a significantly lower polymerization stress than the other materials tested. Except for all materials showed a statistically significant increase in polymerization force after 24 h. compared to the results after 4 min. 2 Polymerization Stress [MPa] Polymerization Stress (Photoelastic Method) Tetric Ceram EsthetiX Z250 Clearfil AP-X Prodigy Condensable P60 SureFil Clearfil Photo Posterior Solitaire 2 InTen-S t = 4 min t = 24 hr 17

18 2. Shrinkage and Stress Polymerization Stress 2 Title: Light-Source, Material and Measuring-Device Effects on Contraction Stress in Composites Published by: L. Musanje, R. L. Sakaguchi, J. L. Ferracane and C. F. Murchison, Oregon Health & Science University, Portland, USA Published at: IADR 2005, Baltimore, USA, Abstract #0294 Aim of the study: The aim of this study was to evaluate contraction stress values of three methacrylate composites and as a function of the light-source and testing device (closed-loop-servohydraulic testing system, Bioman, Low Compliance Device) Results: Low Shrink Posterior Restorative showed significantly lower contraction stress values than the methacrylate based composites independent of the light-source in the low compliance testing device. Polymerization Stress (Low Compliance Device) as determined with different curing lights 5 4 VIP Freelight 2 contin. Freelight 2 ramp Stress [MPa] Tetric Ceram Z250 Heliomolar 18

19 2. Shrinkage and Stress Polymerization Stress and Mechanical Properties Title: Polymerization contraction stress in light-cured composite restorative materials Executed by: K. Gonczowski 1, A.Visvanathan 2, N. ILIE 2, and K.-H. Kunzelmann 2, 1 Jagiellonian University, Krakow, Poland 2 University of Munich, Germany Published at: CED 2005, Amsterdam, The Netherlands, Abstract # Aim of the study: High contraction stress as well as early start of stress build-up and rapid contraction force development in the composite materials may be the reasons for failures of bond to tooth structure. The purpose of the present study was assessment of the polymerization stress and the mechanical properties of different types of composites. Results: The results of the study indicate that the polymerization stress and mechanical properties of the silorane composite are generally superior in maintaining the balance between the high mechanical resistance and good kinetic behavior compared to the other composite materials. Polymerization Stress (Stress-Strain Analyzer) 7 6 Stress [MPa] Tetric EvoCeram CeramX Supreme Z250 Dyract Xtra QuiXfil Grandio 19

20 2. Shrinkage and Stress Polymerization Stress and Curing Lights 2 Title: Low shrinkage composite for dental application Published by: N. Ilie, E. Jelen and R. Hickel, University of Munich, Germany Published at: IADR 2007, New Orleans, USA, Abstract #0398 Aim of the study: The purpose of this study was to analyse the shrinkage behaviour of an innovative composite material for dental restoration based on a monomer with a new chemical formulation with a focus on the the influence of the irradiation regime. Results: Low Shrink Posterior Restorative reveals low polymerization stress values in comparison to regular methacrylate composites; nevertheless stress due to thermal contraction after the end of the light exposure is not negligible and can be additionally reduced by applying the appropriate curing strategy. Polymerization Stress in relation to different curing strategies Curing unit Regime Time [s] Energy density [J/cm²] Mini L.E.D. (Satelec) Serial No.: Bluephase (Ivoclar Vivadent) Serial No.: Polymerization stress [MPa] Gradient m abc (0.4) Fast-cure bc (0.5) 1.0 B (0.1) c (0.2) a (0.2) Pulse abc (0.2) 0.7 A (0.2) c (0.2) Step-cure ab (0.3) 0.7 A (0.2) c (0.5) HIP (High Power) d (0.4) 2.1 C (0.3)* e (0.6) *identical superscript letter indicate no statistical difference, ANOVA ( = 0.05) and post-hoc Tukey s test. 20

21 2. Shrinkage and Stress Polymerization Stress Title: Shrinkage stress of new experimental low shrinkage resin composites Published by: A. Schattenberg, G. R. Meyer, B. Willershausen, and C. P. Ernst, University of Mainz, Germany Published at: IADR 2007, New Orleans, USA, Abstract #0412 Aim of the study: Low shrinkage resin composites are the focus of research in posterior resin composite restoratives. The aim of this study was to examine the polymerization shrinkage stress of experimental low shrinkage resin composites (K0152/Dentsply, NEUN/Heraeus, Hermes/3M ESPE) in comparison to new and established low shrinkage resin composites (Tetric EvoCeram/Ivoclar Vivadent, QuiXfil/ DENTSPLY, Xtrafil/VOCO). Results: New low shrinkage resin composite formulations are able to show a significantly reduced shrinkage stress compared to most of the conventional resin composites investigated. After 24h, the experimental silorane restorative Hermes showed the lowest polymerization shrinkage stress. 2 Polymerization Stress (Photoelastic Investigation) of Low Shrinkage Composites 5 Shrinkage Stress [MPa] Tetric EvoCeram QuiXfil Xtrafil K0152 NEUN Hermes Note: The material Hermes corresponds to. 21

22 2. Shrinkage and Stress Polymerization Stress 2 Title: Shrinkage-Stress Kinetics of versus Dimethacrylate Resin-Composites Published by: D. C. Watts, and M. A. Wahbi, University of Manchester, UK Published at: IADR 2005, Baltimore, USA, Abstract #2680 Aim of the study: -based monomers have been developed as an alternative to dimethacrylate monomers as the matrix phase of composites. The aim was to characterise the kinetics of polymerization shrinkage-stress for this silorane composite system. Results: Low Shrink Posterior Restorative had significantly lower maximum-stress values (2.08 +/-0.03) than the methacrylate which ranged from 4.7 to 7.0 M.Pa. Maximum shrinkage-stressrates for dimethacrylates were from 0.51 to 1.28 M.Pa s -1, but only 0.07 M.Pa s -1 for the silorane. A considerable reduction in both shrinkage-stress magnitude and in peak-stress-rate was apparent with the silorane composite, as compared to established dimethacrylate materials. This class of material should be adequately irradiated at or above, 500 mwcm -2 to achieve optimum properties of, and stress-transfer by the matrix. 22

23 2. Shrinkage and Stress Polymerization Stress Title: Simulation of Spatial Distribution of Polymerization Stress Executed by: A. Versluis, University of Minnesota, USA Unpublished data Aim of the study: The purpose of this study was to compare the spatial distribution of polymerization stress of QuiXfil and by Finite Element Analysis. 2 Results: The simulation shows absence of high stress gray areas where enamel cracks and leakage at the margin can occur. Finite element analysis of and QuiXfil restorations Most stress MPa 50 Restoration: Restoration: QuiXfil 0 Least stress 23

24 3. Tooth Deformation Cusp Movement during Polymerization Title: ESPI Analysis of Tooth Deformation during Polymerization of s Published by: S. Bouillaguet 1, J. Gamba 2, J. Forchelet 2, I. Krejci 1 and J. C. Watanabe 3, 1 University of Geneva, Switzerland, 2 School of Engineering, Yverdon, Switzerland, 3 Medical College of Georgia, USA Published in: Dental Materials (2006) 22: Aim of the study: In the current study, electronic speckle pattern interferometry (ESPI) was used to measure tooth deformation in response to polymerization of five resin composites with a range of polymerization shrinkage. The hypothesis was that composites with higher polymerization shrinkage should cause more cuspal strain as measured by ESPI. Results: The rate of polymerization shrinkage appeared to mediate the development of cuspal strain. Low Shrink Posterior Restorative showed the lowest shrinkage value and induced the least tooth deformation. Cusp Displacement (ESPI) 8 7 Cusp Displacement (microns) Time (sec) Note: The material Hermes corresponds to. 24

25 3. Tooth Deformation Cusp Movement Title: Cusp Movement During Polymerization Using Experimental Low-Shrinkage Composites Published by: G. A. Laughlin and R. Sakaguchi, Oregon Health & Science University, Portland, USA Published at: IADR 2005, Baltimore, USA, Abstract #0622 Aim of the study: One of the most significant adverse characteristics of currently used composite restorative materials is polymerization shrinkage. Materials formulated from novel monomer systems have been suggested as alternatives, and have produced significantly lower shrinkage and stress in various in vitro experiments. The objective of this study was to determine if trends observed in these experiments would be seen in a more clinically relevant application, such as in restoring extracted teeth. 3 Results: The findings were consistent with previous shrinkage and stress results for these composites. The relatively high shrinkage Bis-GMA composite caused more cusp deflection due to shrinkage than the experimental lower shrinkage composites. This preliminary study suggests that the reduction in polymerization shrinkage of new composite systems could result in dramatic differences in their clinical performance. Microstrain Cusp movement as determined by microstrain (µε) ten minutes after polymerization Z250 Oxirane Note: Oxirane is an experimental material not available on the market. 25

26 4. Adhesion and Marginal Quality Tensile Bond Strength Title: Bond Strength of LS System to Tooth Structure Published by: R. Yapp and J. M. Powers, Dental Consultants, Inc., USA Published in: The Dental Advisor 12, August 2007 Aim of the study: The purpose of this study was to evaluate the in-vitro bond strengths of LS Low Shrink Posterior Restorative in combination with its dedicated adhesive and other commercial resin composites with total-etch and self-etch bonding agents to human tooth structure. 4 Results: The LS System ( LS Restorative / LS System Adhesive) bonded equally well in vitro to both human cut enamel and superficial dentin and had tensile bond strengths that were equal to or better than several commercial resin composites bonded with total-etch and self-etch bonding systems. Strength of Adhesion (Tensile Bond Strength) Cut Enamel Superficial Dentin Stress [MPa] Clearfil SE Bond / Clearfil APX Futurabond NR / Grandio Prime & Bond NT / Esthet-X AdheSE / Tetric EvoCeram Xeno III / QuixFil Optibond All-in-One / Premise LS System Adhesive / LS Note: LS System ( LS Restorative / LS System Adhesive) corresponds to System ( Restorative / System Adhesive) 26

27 4. Adhesion and Marginal Quality Tensile Bond Strength Title: Adhesion of System Adhesive to Enamel and Dentin Executed by: J. Fischer, B. Stawarczyk, University of Zurich, Switzerland Unpublished data Aim of the study: The purpose of this study was to evaluate the adhesion of System Adhesive in combination with and methacrylate-based systems after water storage (H 2 O, 24 h) and thermocycling (TC, 1500 cycles, 5 C / 55 C). Results: The adhesion of the Restorative System to enamel and dentin after water storage and thermocycling was in the range of clinically proven restorative systems. 4 Reliability of adhesion (tensile bond strength after water storage [H 2 O] and thermocycling [TC]) Bond Strength [MPa] / System Adhesive Enamel H 2 O Enamel TC Dentin H 2 O Dentin TC Tetric EvoCeram/ Adhese Clearfil AP X/ Clearfil SE 27

28 4. Adhesion and Marginal Quality Film Thickness Title: Film Thickness of Adhesives for and Methacrylate Restorative Composites Published by: C. Thalacker, K. Dede, W. Weinmann, R. Guggenberger, T. Luchterhandt and O. Kappler, 3M ESPE AG, Seefeld, Germany Published at: IADR 2007, New Orleans, #2003 Aim of the study: The goal of this study was to compare the film thickness of the filled two-step self-etch adhesive for a cationic curing based filling material with a polymerization shrinkage of <1% (Bonded Disc Method) to that obtained with filled adhesives for conventional methacrylate composites. 4 Results: Bond showed a comparable film thickness to Clearfil SE Bond and a significantly lower film thickness than Optibond FL. The filled adhesives investigated in this study provided relatively homogeneous films. Film Thickness [MPa] Film Thickness of System Adhesive and Marketed Materials / Bond Clearfil AP X/ Clearfil SE Premise / Optibond FL 28

29 4. Adhesion and Marginal Quality SEM Marginal Evaluation Title: Chewing Simulation of and Methacrylate Restorations Published by: O. Kappler, H. Loll, W. Weinmann and C. Thalacker, 3M ESPE AG, Seefeld, Germany Published at: CED 2007, Thessaloniki, # 0537 Aim of the study: The goal of this study was to compare the marginal integrity of a cationic curing silorane composite with a polymerization shrinkage of <1% (bonded disc method) in combination with its selfetching system adhesive with conventional methacrylate systems before and after chewing simulation. Results: The combination Low Shrink Posterior Restorative/ System Adhesive resulted in a significantly higher percentage of continuous margins before and after chewing simulation than the methacrylate systems tested. 4 % continuous margin (enamel and dentin) Marginal Integrity before and after chewing simulation (thermocycling with cyclic loading) before after 0 Tetric EvoCeram/ AdheSE QuiXfil /Xeno III / System Adhesive 29

30 4. Adhesion and Marginal Quality SEM Marginal Evaluation Title: Marginal Integrity of the System and self-etch adhesives in class I cavities Executed by: U. Blunck, Charité, Berlin, Germany Unpublished data Aim of the study: Adhesive systems are used to improve the marginal seal of composite resin restorations at the interface to enamel and dentin. In the current study the marginal seal to enamel was tested in Class I cavities by SEM analysis of replicas. The System consisting of the self-etching System Adhesive and Restorative was compared to several current self-etch adhesives in combination with methacrylate-based composites. 4 Results: System showed only little gap formation before and after thermocycling in comparison to the reference materials. It can be concluded that the tested two-step self-etch adhesive, System Adhesive, in combination with Restorative is effective in the marginal adaptation in enamel of Class I restorations. Marginal Gap [%] Marginal Gaps before and after thermocycling (TC) System 0* 0* 0* G-Bond / Gradia Direct Posterior Adhese / Tetric EvoCeram Futurabond NR / Grandio Xeno III / Quixfil before TC after TC One up Bond / Estelite Sigma * A value of 0 indicates that no gaps were detected 30

31 4. Adhesion and Marginal Quality Microleakage Title: Microleakage Evaluation of a New Low-shrinkage Composite Restorative Material Executed by: PCV Yamazaki, AKB Bedran-Russo, PNR Pereira, EJ Swift Jr Published in: Operative Dentistry, 2006, 31-6, Aim of the study: This study compared the microleakage of an experimental low-shrinkage resin composite (Hermes), a nanofilled resin composite material ( Supreme) and a hybrid resin composite (Tetric Ceram) using a dye penetration in Class I cavities. Results: Incremental placement remains the preferred restorative technique for direct composites. To reduce the effects of polymerization shrinkage on marginal quality, the low shrink Hermes system might become a good alternative in clinical practice. Note: The material Hermes corresponds to Restorative which was applied with an experimental adhesive. 4 31

32 5. Mechanical / Physical Properties Degree of Conversion Title: -based Dental Composite: Behavior and Abilities Executed by N. Ilie and R. Hickel, University of Munich, Germany Published in: Dental Material Journal (2006) 25: Aim of the study: The purpose of this study was to examine the characteristics of an innovative composite material for dental restorations based on silorane. Degree of conversion was determined at 2 mm and 6 mm depth as a function of curing regimes. Results: s exhibit good mechanical properties comparable to those of clinically successful methacrylate-based composite materials. No differences in degree of cure were noted at 2 mm and 6 mm depth with the tested curing units. 5 Degree of Conversion of as determined by different curing regimes Type Curing unit Regime Time [s] DC [2 mm] DC [6 mm] (layered in 3 increments) LED Halogen Mini L.E.D. (Satelec) Serial No.: Bluephase (Ivoclar Vivadent) Serial No.: Freelight 2 (3M ESPE) Serial No.: Astralis 10 (Ivoclar Vivadent) Serial No.: Fast-cure Pulse cdef (2.7) 61.3 fgh (2.1) 66.8 lm (3.0) 56.8 ab (4.5) 64.3 hijklm (2.7) 66.4 lm (2.7) 57.3 abc (4.4) 62.5 fghij (2.2) 64.6 ijklm (1.1) 55.3 a (5.5) 61.6 fgh (2.5) 64.0 ghijklm (1.0) Step-cure hijklm (6.2) 57.0 ab (1.5) HIP Standard HIP ef (3.1) 61.9 fghi (2.7) 64.9 jklm (4.9) 62.4 fghij (1.4) 65.6 klm (1.9) 66.5 lm (2.8) 60.5 ef (4.5) 63.0 fghijk (2.3) 64.9 jklm (4.2) Superscript letters indicate statistically homogenous subgroups Tukey s HSD test abcd (1.9) 58.2 bcde (3.2) 60.5 ef (3.2) 57.5 abcd (2.8) 63.7 ghijkl (1.9) 64.7 ijklm (2.9) 55.8 ab (3.4) 58.2 bcde (1.1) 60.3 def (1.1) 32

33 5. Mechanical / Physical Properties Degree of Conversion and Shrinkage Stress Title: Degree of Conversion and Shrinkage Stress of Composite Published by: H. M. EL-Damanhoury 1, B. K. Moore 1, A. N. Habib 2, M. A. AL-Hassan 2 and N. M. Aboul-Enein 3, 1 Indiana University, Indianapolis, USA, 2 University of Cairo, Egypt, 3 Suez Canal University, Ismalia, Egypt Published at: IADR 2007, New Orleans, Abstract #2682 Aim of the study: -based composite was introduced as a restorative material with lower polymerization shrinkage stress. The purpose of this study was to evaluate the effect of utilizing two different light sources on the degree of conversion (DC) and the polymerization shrinkage stress of the silorane-based composite and compare them to methacrylate-based composites. Degree of Conversion [%] Results: -based composites showed significantly lower shrinkage stresses than any of the other tested materials, while the degree of conversion was not significantly different. Degree of Conversion and Shrinkage Stress with Two Different Curing Systems Degree of Conversion Shrinkage stress Prisme Aelite Z250 QTH (Halogen Light, 600 mw/cm 2 ) Shrinkage Stress [MPa] 5 Degree of Conversion [%] Degree of Conversion Shrinkage stress Prisme Aelite Z250 LED (1400 mw/cm 2 ) Shrinkage Stress [MPa]

34 5. Mechanical / Physical Properties Flexural Strength Title: Determination of the Flexural Strength of and Methacrylate-Based Composites Executed by: N. Ilie and K.-H. Kunzelmann, University of Munich, Germany Unpublished data Aim of the study: The aim of the study was to determine the flexural strength of and methacrylate based composites. The materials were fixed at two points and stress was applied to a third point until fracture. During the test, compressive forces built up on the upper side and tensile forces at the lower side. Results: The flexural strength of Low Shrink Posterior Restorative lies within the range of clinically proven composites and is substantially above the ISO 4049 limit of 80 MPa. 5 Flexural Strength [MPa] Flexural Strength (ISO 4049) Z100 Z250 Tetric Ceram Heliomolar Prodigy InTenS QuiXfil 34

35 5. Mechanical / Physical Properties Flexural Modulus and Hardness Title: -based Dental Composite: Behavior and Abilities Executed by: N. Ilie and R. Hickel Published in: Dental Material Journal (2006) 25: Aim of the study: The purpose of this study was to examine the characteristics of an innovative composite material for dental restorations based on silorane a monomer with a new chemical composition, and thereby compare the examined characteristics against those of well known methacrylate-based composites. Results: s exhibit good mechanical properties comparable to those of clinically successful methacrylate-based composite materials. No significant differences were observed for hardness and modulus of elasticity between 2 mm and 6 mm depth. Vickers Hardness and Modulus of Elasticity of 5 Curing unit Regime Time [s] HV 2 mm [N/mm 2 ] Mini L.E.D. Bluephase Freelight 2 Astralis 10 Fast-cure Pulse (4.1) 73.7 (1.0) 79.8 (4.6) 73.4 (2.2) 75.2 (0.1) 82.2 (5.2) HV 6 mm [N/mm 2 ] 71.9 (4.6) 72.6 (6.6) 73.7 (6.2) 70.1 (8.2) 71.4 (5.1) 74.4 (6.3) E 2 mm [GPa] 12.7 (0.1) 12.4 (0.2) 12.7 (0.6) 12.8 (0.2) 12.6 (0.2) 13.4 (0.3) E 6 mm [GPa] 12.0 (0.4) 11.8 (0.8) 12.4 (0.6) 11.9 (0.4) 12.5 (0.2) 12.4 (0.4) Step-cure (1.0) 74.2 (6.6) 12.5 (0.5) 12.8 (0.4) HIP Standard HIP (4.0) 78.8 (2.1) 78.5 (4.4) 79.9 (3.4) 82.5 (9.2) 81.7 (5.7) 80.8 (7.7) 81.5 (2.9) 80.8 (5.0) 68.6 (5.5) 72.1 (4.4) 75.7 (6.1) 69.4 (6.7) 76.6 (10) 76.6 (10) 68.2 (5.7) 72.3 (8.0) 73.9 (4.0) 12.7 (0.6) 12.5 (0.9) 12.8 (0.4) 12.4 (0.7) 12.8 (1.1) 13.5 (0.1) 12.6 (0.6) 12.4 (0.5) 12.5 (0.4) 11.2 (0.8) 11.9 (0.9) 12.3 (0.3) 12.2 (0.9) 12.7 (1.0) 13.0 (1.2) 11.6 (1.5) 11.7 (2.1) 12.5 (0.3) 35

36 5. Mechanical / Physical Properties Compressive Strength and Flexural Strength Title: Compressive Strength and Flexural Strength of and Methacrylate-Based Composites Executed by: W. Weinmann, A. Stippschild, 3M ESPE AG, Seefeld, Germany Unpublished data Aim of the study: The aim of this study was to evaluate compressive strength and flexural strength of compared to methacrylate-based composites. Results: Both the compressive strength and flexural strength of Low Shrink Posterior Restorative rank within the range of clinically proven composites and are substantially above the ISO 4049 limit of 80 MPa (flexural strength). 5 [MPa] Compressive Strength and Flexural Strength (ISO 4049) Compressive Strength Flexural Strength Glacier Aelite LS Packable QuiXfil ELS CeramX Duo Tetric EvoCeram Heliomolar Grandio EsthetX TPH 3 Venus Supreme Preimise 36

37 5. Mechanical / Physical Properties Flexural Fatigue Limit Title: Determination of the Flexural Fatigue Limit of Resin Based Composites and Executed by: M. Braem, University of Antwerp, Belgium Unpublished data Aim of the study: Restoration fracture due to material fatigue is one of the main reasons for failure of direct restorations. To obtain insight into the fatigue behavior of its flexural fatigue limit was determined and compared with conventional methacrylate composites. In this test 10,0000 cycles of 3-point loading were applied with the frequency of 2 Hz, which is the upper limit of chewing frequency, under wet conditions and a constant temperature of 35 C. Several tests were done for each material, increasing the stress compared to the previous test if a material did not fail, and decreasing the stress if the material broke under loading. This procedure is referred to as the staircase approach. Results: The flexural fatigue limit of Low Shrink Posterior Restorative under wet condition reaches top level, indicating that under clinical conditions will likely withstand mastication forces without fracturing even after many years in service. 5 Flexural Fatigue Limit Shear Flexural Fatigue Limit [MPa] Charisma Tetric Ceram Z250 Surefil Prodigy Condens. Solitaire 2 37

38 5. Mechanical / Physical Properties Fracture Toughness (K IC ) Title: Fracture Toughness of and Methacrylate-Based Composites Executed by: K.-H. Kunzelmann, University of Munich Unpublished data Aim of the study: Fracture toughness is a measure of the resistance of a material to crack propagation. A high fracture toughness means clinically that a small crack needs more mechanical impact to cause a failure of the restoration. Results: The fracture toughness of Low Shrink Posterior Restorative is in the range of clinically proven methacrylate composites. 5 Fracture Toughness, resistance to crack propagation KIC Z250 Tetric Ceram Heliomolar Prodigy QuiXfil 38

39 5. Mechanical / Physical Properties Viscoelastic Stability Title: Creep of solvent-aged silorane, Ormocer and dimethacrylate matrix composites Published by: D.C. Watts, and H. Y. Marghalani, University of Manchester, UK Published at: IADR 2007, New Orleans,USA, Abstract #0235 Aim of the study: The purpose was to study time-dependent viscoelastic deformation (creep and recovery) of new composite formulations with different matrix structures, under compressive load, after aging in food-simulating solvents of different solubility parameter. The hypotheses to be tested were that: (i) viscoelasticity would vary with solubility parameter and that (ii) materials with the newer matrix chemistries would be more dimensionally stable under load. Results: The materials all exhibited classic creep and recovery curves. Two new-matrix composite types: silorane and Ormocer, exhibited viscoelastic stability in food-simulating solvents. But this behaviour was closely matched by one highly-filled dimethacrylate material. 5 39

40 5. Mechanical / Physical Properties Hydrolytic Stability Title: Hydrolytical Stability of a and Three Methacrylate Composites Published by: R. Guggenberger, C. Thalacker, A. Syrek, A. Stippschild and W. Weinmann, 3M ESPE AG, Seefeld, Germany Published at: IADR 005, Baltimore, Maryland, USA, Abstract #3093 Aim of the study: The goal of this study was to investigate the hydrolytical stability of an experimental based filling material in comparison to conventional methacrylate-based systems. Thus, their water sorption was correlated with their flexural strength (FS) after water storage and a boiling stress test. Results: The material exhibits statistically the lowest amount of water sorption. There was no statistical difference among all materials regarding the development of the flexural strength after 7d 36 C. The boiling test for 10 h revealed that the silorane material and Prodigy Condensable showed the most robust hydrolytical stability. 5 Water sorption and FS according to ISO Standard deviations are given in parentheses. Means with the same letters are statistically the same. Material Manu facturer Water sorption µg/mm 3 FS ISO [MPa] Ratio FS 7d 36 C / ISO [%] 3M ESPE 9.2 (0.6)a 124 (9)e 105 (9)f 89 (8)g Tetric Ceram Ivoclar 19.6 (0.7)c 127 (14)e 99 (7)f 77 (5)i Vivadent Quixfil Dentsply 11.7 (0.9)c 130 (29)e 104 (2)f 80 (7)hi Prodigy Condensable Kerr 15.2 (0.9)d 140 (24)e 101 (4)f 86 (5)gh Ratio FS 10h 100 C / ISO [%] 40

41 5. Mechanical / Physical Properties Hydrolytic Stability Title: The influence of short and medium-term water immersion on the hydrolytic stability of novel low-shrink dental composites Executed by: W. M. Palin 1, G. J. P. Fleming 1, F. J. T. Burke 1, P. M. Marquis 1, R. C. Randall 2, 1 University of Birmingham, UK, 1 3M ESPE, St. Paul, USA Published in: Dental Materials (2005) 21, Aim of the study: The aim of the current study was to investigate the effect of water uptake characteristics and water solubility on the mechanical properties of two methacrylate (Z100 and Z250), an experimental oxirane (OXI) and silorane (SIL) resin based composites (RBC) following short- and medium-term immersion. Results: exhibited the significantly lowest water sorption, solubility and associated diffusion coefficient following each immersion period. This may potentially improve hydrolytic stability of composite restorations. Water sorption and water solubility after storage in water (37 C) 5 Immersion periods [weeks] Material Water sorption [µg mm 3 ] Water solubility [µg mm 3 ] Z (0.5) b 0.92 (0.09) b 1 Z (0.3) c 0.36 (0.09) c OXI (1.0) a 2.28 (0.11) a SIL 6.63 (0.5) d 0.26 (0.07) c Z (0.5) b 0.92 (0.12) b 4 Z (0.5) c 0.49 (0.10) c OXI (1.0) a 2.94 (0.16) a SIL 8.04 (0.6) d 0.28 (0.07) d 12 Z (0.9) b 0.89 (0.08) b Z (0.6) c 0.49 (0.07) c OXI (0.7) a 2.90 (0.19) a SIL 8.74 (1.1) d 0.29 (0.07) d Z (1.4) b 0.95 (0.16) b 26 Z (0.8) c 0.54 (0.11) c OXI (1.2) a 2.95 (0.17) a SIL 9.40 (0.8) d 0.26 (0.07) d Standard deviations are displayed in parentheses. Similar superscripts within each immersion period signify no significant difference between materials (P<0.05). 41

42 5. Mechanical / Physical Properties Oxygen Inhibition Layer Title: Reducing the depth of oxygen inhibition in resin-based composites Published by: S. Mohammed, W. M. Palin and A. C. Shortall, University of Birmingham, UK Published at: IADR 2007, New Orleans, USA, #2673 Aim of the study: To investigate the effect of monomer chemistry and filler content on oxygen diffusion and curing extent near to the irradiated surface of resin-based composites (RBCs). Results: resin chemistry may eliminate oxygen inhibition near the cured surface. The depth of inhibition is complicated by filler content which may act as a diffusion barrier or adsorb oxygen onto the filler surface. 5 42

43 5. Mechanical / Physical Properties 3-Body Wear Title: 3-Body Wear of and Methacrylate based Composites Determined by Means of the ACTA Machine Executed by: T. DeGee, University of Amsterdam (ACTA), Netherlands Unpublished data Aim of the study: Wear resistance is a critical factor especially for the survival of posterior restorations. In this study the wear resistance of and methacrylate based composites was determined by means of the ACTA-wear machine. In this machine a structured steel wheel rotated against a composite sample wheel in a millet gruel suspension, causing a trace in the samples. The deeper the trace, the less wear resistant is the composite. Wear was determined after 200,000 revolutions and different storage times by measuring the depth of the trace that the steel wheel has caused on the composite samples. Results: The wear resistance of Low Shrink Posterior Restorative was similar to clinically proven resin composites. 5 Wear [µm/200,000 revolutions] Abrasion (ACTA, 3-body wear) Spectrum TPH 1 day 4 days 1 week 1 month 2 months Prodigy Condensable InTen-S Tetric Ceram 43