4 Seasons Scientific Profile.rj

Seasons

速

DIRECT ESTHETIC COMPOSITE SYSTEM

Scientific Profile MAY 2003

4 Seasons®

Table of contents 1. Introduction . . . . . . . . . . . . . .

1.1 Structure of teeth . . . . . . .

1.2 Shade systems . . . . . . . . . .

1.3 Optical properties of teeth 1.4 The 4 Seasons® system . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

. . . . .

.3 .3 .4 .5 .6

2. Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

3. In vitro investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 3.1 Color, opacity and translucency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 3.2 Filler composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.3 Wear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

4. Clinical investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 4.1 Dr. Joseph Dennison, University of Michigan, USA . . . . . . . . . . . . . . . . . . . . . . . . . .13 4.2 Dr. Gerard Kugel, Tufts University, Boston, USA . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 4.3 Dr. Pier Nicola Mason, University of Padua, Italy . . . . . . . . . . . . . . . . . . . . . . . . . . .14 4.4 Dr. Knut Merte, Universitätsklinikum Leipzig, Germany . . . . . . . . . . . . . . . . . . . . . .14 4.5 Dr. Arnd Peschke, Internal Clinic, R&D Ivoclar Vivadent, Schaan, Liechtenstein . . . .14

5. Toxicology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

6. Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

2

Scientific Profile

1. Introduction The increasing demand for tooth-colored restorations and the dentist’s artistic understanding and skill have led to a resurgence in direct composite restorative systems in the past few years. Dental manufacturers have developed modern composite and ceramic-based materials, which are indistinguishable from natural dentition. These possibilities have not only caused patients to increase their dental IQ and esthetic expectations, but they have also spurred the ambitions of esthetically-aware dentists.

Consequently, dentists specializing in esthetic dentistry are requiring materials which offer convenience as well as esthetic possibilities more than ever before.

Natural teeth are composed of dentin and enamel, embedded in pink soft tissue. Light passes through them, entering them from the front. Some light is reflected from the surface of the tooth, the remainder penetrates the surface and is either reflected, refracted or absorbed by the inner layers of the tooth or passes through the entire tooth into the dark oral cavity. The typical color and light effects, which are created in the process, constitute the hallmark of the natural appearance of teeth. It goes without saying that restorations which mimic only the shade and shape of natural teeth are easily recognized as foreign even by the untrained human eye. They must also mimic their treatment of light.

Bearing the structure of teeth in mind, we realize that truly indiscernible, lifelike restorations can only be fabricated if an adequate range of dentin, enamel and characterization materials are available – materials that allow not only the reconstruction of the external shade and shape but also the reproduction of the inner tooth structure and the resultant optical effects.

The following section will explore the natural structure and optical properties of teeth and provide an introduction to the 4 Seasons® restorative system.

1.1 Structure of teeth The outermost layer of the exposed tooth consists of enamel, the hardest component of the tooth. The inner bulk of the tooth is dentin, which is softer and has less minerals than the enamel. In the center is the pulp, a living tissue (Fig. 1a). Most restorations involve the replacement of lost tooth structure with a suitable restorative material. The aim of esthetic dental restorations is to replace lost tooth structure in as lifelike a manner as possible.

Enamel Enamel is extremely hard, consisting of 96% (wt) hydroxyapatite and 4% (wt) organic material and water (Eisenmann, 1998).

Enamel is made up of rod-like prisms of approximately 5 µm in diameter (Fig. 1b). The hydroxyapatite crystals are packed together in the prisms in parallel order to the longitudinal side of the rods. The enamel rods are aligned roughly at right angles to the amelo-dentinal junction, whereas angles ranging from 55 to 100° are measured between the prisms and the outer tooth surface.

The only areas where the enamel rods are arranged vertically to the tooth surface are the cusp tips and proximal edges (Fernandez and Chevitarese, 1991). The enamel prisms do not run a straight course from the amelo-dentinal junction to the outer surface.

Groups of prisms make a series of bends along the course. This gives rise to what is know as the Hunter-Schreger bands (Fig. 1c). Thus, the enamel is characterized by a subtle, intricate substructure. This well-ordered structure is also responsible for the typical etching pattern, which forms in the course of etching the enamel with acid (Fig. 1b, 1c).

3

4 Seasons®

Fig. 1a: Schematic structure of a molar.

Fig. 1b: Scanning electron micro-graph

Fig. 1c: Scanning electron micro-graph

S, enamel; D, dentin; SD, amelo-dentinal junction; P, pulp; Z, gingiva; L, periodontal membrane; K, bone.

showing etched enamel. The enamel rods are cut in an oblique manner.

showing etched enamel The enamel rods are cut longitudinally.

Dentin The bulk of the human tooth is dentin. Dentin consists of 45% (vol) mineral and up to 30% (vol) organic material by volume. Water makes up approximately 25% (vol) of the dentin (Schroeder, 1991). The inorganic components are mainly hydroxyapatite and the organic material is predominantly collagen (Torneck, 1998).

A characteristic feature of dentin is the dense arrangement of dentin tubules that traverse its entire thickness. A density of 59,000 to 76,000 tubules per mm2 can be observed in the vicinity of the pulp (Torneck, 1998). The diameter of dentin tubules is approximately 2.5 µm near the pulp and 0.9 µm at the amelo-dentinal junction (Garberoglio and Brännström, 1976).

1.2 Shade systems Dental materials are predominantly described in terms of their shade and transparency. Shade guides are used to help dental professionals select the appropriate shade or inform the laboratory about the shades selected. The Chromascop (Ivoclar Viadent) and A-D (Vita) shade guides are examples of such shade systems.

Shade guides have become the standard for selecting shades by their visual qualities as seen by the human eye.

However, shade guides are hardly suitable for industrial or scientific purposes, such as assuring uniform color properties among different lots of materials or the research-centered shade measuring of teeth. Consequently, electronic shade matching devices, which perform reproducible quantitative shade measurements, are gaining in popularity. To date, these devices predominantly use the CIELAB L*, a*, b* color co-ordinates (Fig. 2).

The L*, a*, b* sets of coordinates has proved to be a valuable system to describe colors. However, this system is not capable of identifying parameters such as opacity or transparency. Yet, these parameters affect the measurement of color and should therefore not be neglected.

Fig. 2: CIELAB L*, a*, b* color co-ordinates. L* describes the lightness component of a color: L*=0 means ‘absolutely black’ and L*=100 means ‘completely white’. The a* co-ordinate plots the color on a red - green axis and the b* co-ordinate indicates the color on a yellow - blue axis.

4

Scientific Profile

1.3

Optical properties of teeth

Teeth are characterized by exceptional optical properties, which by far transcend the qualities associated with just color. For instance, teeth have fluorescent properties. In addition, dentin is far more opaque and intensely saturated in color than enamel, whereas enamel features additional opalescent qualities. While the components of color can be measured and described, properties such as translucency, opacity and opalescence are much more difficult to determine objectively. Color measuring in the oral cavity appears to be rather difficult because the surrounding components and the reflections on the tooth surface affect the optical appearance of a tooth quite considerably.

Furthermore, extracted teeth, which are no longer in contact with saliva, look different from what they used to do in the oral cavity. It is no surprise that publications measuring the optical properties of teeth are limited. A few of them are briefly discussed below.

A Japanese team of researchers measured the color of anterior teeth with a colorimeter in randomly selected Japanese people (Hasegawa et al., 2000). By and large, the study reflects the evaluation of teeth as seen by the human eye. From the incisal to the cervical region of teeth, the red and yellow components gradually increase.

The translucency is much higher along incisal edges, which are predominantly composed of enamel, than at the cervical sites. The pronounced shift towards red at the cervical margin may be attributed to the adjacent gingival or the more saturated dentin closer to the surface.

Another study measured the color of extracted upper incisors. The following color co-coordinates were measured along the central part of the teeth: L*, 70 Âą 4: a*, -0.22 Âą 1.4; b*, 18 Âą 3 (ten Bosch and Coops, 1995). After removing the enamel, the color of the remaining dentin was measured again. A high level of correlation was observed between the color measurements of the entire tooth and the dentin core. From these measurements the authors concluded that tooth color is mainly determined by the color of dentin. This fact, consistent with the visual determination during cross-sectioning of a natural tooth, is the foundation of the anatomical build-up and Value Shade system included in the 4 Season System.

5

4 Seasons速

1.4 The 4 Seasons system An esthetic restorative material should enable the dental professional to imitate the optical properties of natural teeth accurately. Consequently, manufacturers are required to supply dentin, enamel and characterization materials whose shades and levels of translucency are coordinated with each other and with natural dentition. On their part, dentists have to use the best possible layering techniques to reproduce the shade, shape and translucency of teeth in such a way that they regain their original appearance. A system that is capable of satisfying all these requirements is, therefore, best developed in close cooperation between the manufacturer, leading clinicians and input from ceramists on achieving lifelike restorations through layering.

In the course of developing 4 Seasons, the consistency and color coordination of the individual components were checked repeatedly by selected external dentists and color experts and subsequently adjusted to customer requirements. The result is a system that embraces forty shades. The table below provides an overview of all the shades and degrees of transparency available.

Shade Category

Shade Designation

Translucency*

Color Code (Cavifil Cap or Syringe Plunger)

Dentin Shades (12 total) Dentin (D)

A1, A2, A3, A3.5, A4, A5, A6 B1, B2 C3 D2 Bleach XL

Similar to natural dentin.

(7-8%)

Enamel Shades (28 total) Enamel Shaded (ES) A1, A2, A3, A3.5, A4 B1, B2, B3, B4 C1, C2, C3, C4 D2, D3, D4 Bleach XXL, XL, L, M

(13-15%) (8-20%)

Enamel Translucent (ET) Enamel Value (EV) Enamel Effects (EE)

(26%, 30%, 56%) (17-23%) (6%, 21%)

Similar to natural enamel.

Amber, Clear, Super Clear Low, Med, Hi White, Blue

Dark Blue

Medium Blue

Light Blue White Black

* Translucency measurements are approximate.

Table 1: 4 Seasons system of materials

Being able to rely on an appropriate range of materials represents the first step towards farbricating an esthetically impeccable restoration. A technique guide has been prepared together with experienced dentists to support dental professionals in their efforts to satisfy the requirements of their patients. Using case presentations as a basis, this guide shows practitioners a route to attain results that meet exacting esthetic demands.

6

Scientific Profile

2. Technical data Standard composition (in weight by %)

RESIN Dimethacrylates FILLERS Barium glass filler, silanized Ytterbium trifluoride Mixed oxide, silanized Ba-Al-fluorosilicate glass, silanized Highly dispersed silicone dioxide OTHER Additives Stabilizers and catalysts Pigments

Dentin

Enamel

Super Clear Amber

22.7

23.2

24.2

76.0

75.4

75.0

1.3

1.4

0.8

4 Seasons is classified as a fine particle microhybrid restorative material. During the extensive development phase, optimized formulations of filler/resin combination, known to be clinically successful, were formulated specifically for the dentin, enamel and characterizing materials with the intent of altering only their optical properties while maintaining handling, physical and clinical performance requirements consistent throughout the entire system.

Physical properties according to EN ISO 4049

Flexural strength (MPa) Flexural modulus (MPa) Compressive strength (MPa) Absorption of water (µg/mm3) Solubility in water (µg/mm3) Radiopacity (% Al) Curing depth (mm) Vickers hardness (MPa) Transparency (%) Density (g/cm3)

Dentin 135 9000 260 19.8 1.0 350 > 3.0 570 7-8 2.25

Enamel 135 9000 260 19.6 1.0 200 > 4.0 570 13 - 15 2.05

Super Clear 135 9000 260 19.6 1.0 200 > 4.0 570 56 2.05

The physical properties of 4 Seasons materials are consistent with those of successful microhybrid materials providing ideal strength in combination with functional resistance and ease of esthetic luster and polishability. What is unique with 4 Seasons is the exacting formulation of each category of shades – providing identical physical properties regardless of the optical possibilities. For example, 4 Seasons Super Clear – with a translucency of over 50% achieves the same functional resistance and high physical properties as does the more opaque underlying dentin shades. This provides the clinician and patient consistent handling and match of material properties regardless of the layering technique used or the individual shades preferred.

7

4 Seasons®

3. In vitro investigations 3.1 Color, opacity and translucency The table below lists the CIELAB color co-ordinates as well as the degrees of opacity and transparency of the individual 4 Seasons materials.

Shade Dentin A1 Dentin A2 Dentin A3 Dentin A3.5 Dentin A4 Dentin A5 Dentin A6 Dentin B1 Dentin B2 Dentin C3 Dentin D2 Dentin Bleach XL Enamel A1 Enamel A2 Enamel A3 Enamel A3.5 Enamel A4 Enamel B1 Enamel B2 Enamel B3 Enamel B4 Enamel C1 Enamel C2 Enamel C3 Enamel C4 Enamel D2 Enamel D3 Enamel D4 Enamel Value – LOW Enamel Value – MED Enamel Value – HI Enamel Bleach XXL Enamel Bleach XL Enamel Bleach L Enamel Bleach M Enamel Effect White Enamel Effect Blue Enamel Trans Amber Enamel Trans Clear Enamel Trans Super Clear

L* Value

a* Green to Red

b* Blue to Yellow

CR (%) Opacity

T(%) Translucency

82 77 75 72 69 66 62 80 77 70 74 82 76 74 74 72 68 77 76 72 71 74 72 69 66 72 70 67 64 73 77 85 82 79 77 88 66 67 74 72

1.0 4.5 5.1 5.8 7.6 8.2 9.1 0.9 1.9 5.1 3.3 -1.4 1.0 1.8 2.7 3.5 6.2 0.3 1.5 4.4 5.5 0.8 1.7 3.5 5.6 2.3 4.8 5.8 -0.6 -1.6 -1.9 -1.1 -1.7 -1.8 -2.1 -0.7 -1.8 1.6 -1.7 -1.4

16.7 21.8 21.3 23.8 24.9 24.3 23.8 15.4 20.8 20.7 18.2 9.4 13.3 16.4 20.4 22.9 25.7 11.6 22.3 26.5 27.0 16.4 18.7 19.6 22.6 16.9 22.2 23.3 5.8 5.5 7.3 7.5 7.5 7.7 9.8 6.5 -5.3 21.6 7.8 10.4

78 79 84 83 81 82 83 81 83 81 84 70 57 63 61 60 61 57 62 64 61 64 66 65 65 60 65 64 47 52 45 77 66 53 47 88 53 39 36 15

7.4 7.9 7.8 7.5 7.6 7.5 7.5 7.8 7.5 7.5 7.5 9.1 14.2 13.7 13.7 13.5 13.8 13.7 13.2 13.9 13.8 13.1 13.9 13.2 13.5 14.2 13.9 13.7 23.2 17.3 20.0 8.0 10.0 15.0 20.0 6.0 21.1 26.0 30.0 56.6

Table 2: CIELAB color co-ordinates, levels of opacity (CR) and translucency (T) of the individual 4 Seasons components

8

Scientific Profile

Calibrated True Colors When the a* b* values of each shade is graphed, the 4 Seasons Enamel and Dentin shades show a very consistent rise in a* and b* values within each shade grouping demonstrating True Color availability across the entire shade range. Similar depiction of competitive materials demonstrate variable results across the entire shade range.

4 Seasons® Dentin Shades

4 Seasons® Enamel Shades

Filtek™ Supreme Body Shades

9

4 Seasons®

Consistent Translucency During the development of the 4 Seasons material rigorous efforts were made to insure consistency in translucency amongst the dentin and enamel subcategories. Meaning, regardless of the shade selected within each group, the individual shade would have a translucency similar to others in its category. Other competitive materials vary not only the shade but also the translucency in their individual groupings. This requires the clinical operator to factor in another variable in the restorative layering process – the translucency. With 4 Seasons, there is tight tolerances in the translucency across the enamel and dentin groupings. Dentin shades of 4 Seasons have a range of 7.4-7.9% translucency whereas the enamel shades have a consistent tight range of 13.2-14.2% translucency. The ranges of competitive materials in translucency across their body, enamel and special shades often blur the differences between enamel and dentin shades.

}

4 Seasons offers a good variance in opacity/translucency between dentin & enamel categories, mimicking natural tooth structure.

6.3%

4 Seasons® Enamel

4 Seasons offers a tight tolerance in translucency within the enamel category.

4 Seasons® Dentin

Esthet•X™ Enamel

Esthet•X™ Dentin

Filtek™ Supreme Enamels/Bodies

± 1.1%

Filtek™ Supreme Dentins

± 3.7%

± 4.0%

4 Seasons®

Esthet•X™

± 0.5% ± 0.6%

Filtek™ Supreme

± 1.2%

4 Seasons offers a tight tolerance in translucency within the dentin category.

4 Seasons®

10

Esthet•X™

Filtek™ Supreme

Scientific Profile

Range of Translucencies in Special Shades 4 Seasons offers a full compliment and varying levels of translucency to select from based upon the clinical situation at hand.

Translucency levels range from 6% (most opaque) to over 56% (most translucent) within the 4 Seasons system showing sequential steps of translucency throughout the range of special shades.

In addition to traditional A-D shades, 4 Seasons offers extra-light and extra-dark shades to meet the esthetic needs of all patients. In addition, highly translucent enamel shades are available for surface characterization, while blue and white enamel effect shades are available for internal characterization.

4 Seasons®

Esthet-X™

Filtek™ Supreme

Vitalescence®

3.2 Filler composition The filler composition plays an even more important role in highly esthetic restorative materials than it does in universal composites. Not only does a highly esthetic material have to fulfill particular requirements related to volume shrinkage, surface hardness, fracture resistance, flexural strength, flexural modulus, polishability, wear resistance and radiopacity, but the optical properties of its fillers and polymer matrix also need to be accurately coordinated with each other. A high level of coordination is vital to attain the shades and degrees of translucency required to achieve true-to-nature restorations.

As a consequence, particular attention was paid to the composition of the fillers in the course of developing 4 Seasons.

The scanning electron micrographs below show the surface of 4 Seasons Enamel and 4 Seasons Dentin after polishing.

Fig. 4: Scanning electron micrograph of 4 Seasons enamel and dentin surfaces after they have been polished to a high gloss. The following fillers can be identified: white, ytterbium trifluoride; light grey, barium glass. The grey background represents the matrix.

Investigation: R&D Ivoclar Vivadent AG, Schaan, Liechtenstein

11

4 Seasons®

3.3 Wear The wear behavior of restorative and prosthetic materials constitutes a vital parameter in the prospects of a restoration or prosthetic reconstruction. Wear processes affect the esthetic appearance and masticatory function of dental restorations. Various types of wear mechanisms come into play in the oral environment; they often occur simultaneously: attrition (two-body wear), abrasion (three-body wear with the food bolus or tooth paste acting as the abrasive agent), erosion (chemical degradation) and fatigue/abfraction (chipping off due to crack formation).

Measuring the wear of dental materials in vivo involves lengthy, inaccurate procedures. Even if high-precision impression materials are utilized, the restorations need to be worn for at least 12 to 24 months until the actual wear exceeds the mean variation of measurements by a large enough margin to allow the rate of wear to be evaluated. For these reasons, dental materials are subjected to in vitro simulations of mastication processes to estimate their stability under clinical conditions.

Ivoclar Vivadent uses a Willytec chewing simulator to measure the wear resistance of restorative materials. Standardized antagonists made of Empress material are used to keep the data variance at a minimum. Plane test samples are subjected to 120,000 masticatory cycles, applying a force of 50N and a sliding movement of 0.7 mm. An abrasive medium is not used in this two-body wear testing method. The vertical substance loss and volume loss are measured by means of a 3D laser scanner.

Volume Loss (mm3)

Vertical Substance Loss (µm)

Fig 5: Volume loss and vertical substance loss of composite materials. The results are ranked according to volume loss, starting with the lowest measurement.

A vertical loss of less than 200 µm is regarded as being low. A loss between 200 – 300 µm represents a moderate rate of wear. In the above test, the wear behavior of both 4 Seasons Dentin and 4 Seasons Enamel closely resembled that of natural enamel.

Investigation: R&D Ivoclar Vivadent AG, Schaan, Liechtenstein

Fig 6: Tiles of materials were placed in the Proto-Tech Oral Wear Simulator. The device mimics masticatory dynamics, specifically employing a human enamel stylus, physiologic load levels, and a foodlike slurry for a third body. Tiles were subjected to 100.000 cycles to mimic approx. 1.5 years of clinical wear in the oral cavity.

Technique as described in: Condon JR, Ferracane JL Dent Mater 1996 Jul;12(4):218-26 Investigation: Ivoclar Vivadent, Inc., Amherst, NY

12

Scientific Profile

4. Clinical investigations Several clinical studies on 4 Seasons have been initiated.

4.1 Dr. Joseph Dennison, University of Michigan, USA Experimental:

53 Class II 4 Seasons restorations were placed in 30 patients with AdheSE, of which 5 were in premolar and 48 in molar teeth.

Current status:

After 6 months, 48 restorations were evaluated. (Pending one year recall results; 93% Patient recall)

Results:

Conclusions:

4 Seasons/AdheSE Marginal adaptation Marginal discoloration Anatomic form Restoration fracture Surface texture Postoperative Sensitivity Proximal contacts Secondary caries Survival

Baseline 91%A, 9%B 100%A 98%A, 2%B 100%A 100%A 91%A, 9%B 92%A, 8%B 100%A 100%A

6 Months 59%A, 37%B, 2%C 100%A 88%A, 12%B 96%A, 2%B, 2%D 96%A, 2%B, 2%C 92%A, 4%B, 2,%C,2%D 95%A, 3%B, 2%A 100%A 96%A, 4%D

During the first 6 months, one restoration was replaced due to endodontic treatment and one due to fracture. All remaining restorations were in clinically acceptable condition.

4.2 Dr. Gerard Kugel, Tufts University, Boston, USA Experimental:

50 Class V restorations were placed with an experimental variant of 4 Seasons using a self-etching adhesive AdheSE速.

Current status:

After 6 months, all restorations were evaluated. (1.5 year recall results due July 2003.)

Results:

At baseline, all restorations were in clinically acceptable conditions with respect to the parameters retention, color match, marginal integrity, anatomic form, secondary caries and gingivitis.

Conclusions:

After 6 months, one restoration lost retention. Marginal discoloration of differing degrees was observed in 5 restorations. In all other mentioned criteria, restorations were in clinically acceptable condition.

13

4 Seasons®

4.3 Dr. Pier Nicola Mason, University of Padua, Italy Experimental:

A total of 60 Class III and IV cavities were restored with 4 Seasons (Artemis®). Excite® total-etch adhesive was used in 30 restorations, and AdheSE® self-etch adhesive was used in the other 30 restorations. The aim of this study was to confirm the surprisingly favorable results that AdheSE® produced in the enamel when examined in Class I and II studies as well as in laboratory investigations. It should be possible to obtain similar results in the anterior region.

Current status:

The study was initiated in December 2002. Six-month results will be available in September 2003.

4.4 Dr. Knut Merte, Universitätsklinikum Leipzig, Germany Experimental:

Thirty patients who required at least two Class I or II restorations were treated with 4 Seasons. According to the split mouth design, one restoration was placed using the Excite total etch adhesive and the other was placed using the AdheSE® self-etch adhesive.

4 Seasons Dentin (Artemis®) and 4 Seasons Enamel (Artemis®) were placed in increments of max. 2 mm and light-cured.

Current status:

All restorations were placed between December 2002 and February 2003.

4.5 Dr. Arnd Peschke, Internal Clinic, R&D Ivoclar Vivadent, Schaan, Liechtenstein Experimental:

The purpose of this investigation is to evaluate the clinical performance of 4 Seasons in conjunction with the tried-and-tested Syntac adhesive system and the newly developed AdheSE self-etch adhesive system in cavities of Classes I to V. All restorations are placed after isolation with a rubber dam and all teeth treated are vital.

Current status:

To date, 42 restorations have been placed using 4 Seasons (Artemis).

Cavity class I II III IV V Total

Results:

Syntac classic 2 12 8 4 2 28

AdheSE 1 5 6 0 2 14

In view of the experience gathered thus far, the clinical performance of the material can be rated impeccable. 4 Seasons is easy to shape and exhibits high stability. The esthetic integration of the material in terms of transparency and shade is excellent; marginal discoloration, chipping of material or fractures have not been observed five months into the investigation. Postoperative sensitivity did not occur in any of the patients treated.

14

Scientific Profile

5. Toxicology 5.1 Introduction Dentists tend to place very high requirements on esthetic composite materials. When 4 Seasons was developed, particular attention was paid to using types of raw material that have been tried-and-tested in dental materials in vivo for many years. Consequently, we can fall back on the experience gathered with proven dental composites and their ingredients to assess the toxicological properties of 4 Seasons. 4 Seasons contains the following fillers: barium glass, barium aluminium fluorosilicate glass, silicone dioxide and ytterbium trifluoride. Like Tetric® and Tetric® Ceram™, the monomer matrix of 4 Seasons is composed of Bis-GMA, urethane dimethacrylate and triethylene glycol dimethacrylate.

5.2 Toxicity of 4 Seasons Fillers composed of glass and silicone dioxide are chemically inert. In addition, the fillers are embedded in a resin matrix in the course of polymerization. Consequently, they do not represent a toxicological risk. The toxicity of the ytterbium trifluoride filler, which endows the Ivoclar Vivadent composites with their excellent radiopaque properties, was tested on rats. None of the rats died when exposed to the highest tested dose of 5000 mg/kg and pathological mutations of organs did not occur [1]. Furthermore, ytterbium trifluoride was tested for any radioactivity that may be present in addition to the naturally occurring radioactivity [2].

Tests showed that the LD5 level of both Bis-GMA and urethane dimethacrylate is higher than 5000 mg/kg [3].

The LD50 level of triethylene glycol dimethacrylate is 10,837 mg/kg. As 4 Seasons comprises the same monomers as Tetric and Tetric Ceram, the toxicology data of these materials may be used to evaluate the toxicological risk of 4 Seasons. The cytotoxic properties of polymerized Tetric were evaluated in an Agaroverlay test using L929 mice cells. In this test, Tetric did not demonstrate a cytotoxic potential [4]. In view of the present data, it is safe to assume that 4 Seasons as well as Tetric and Tetric Ceram do not involve any relevant toxicological risk.

5.3 Mutagenicity of 4 Seasons As 4 Seasons contains the same monomers as Tetric and Tetric Ceram, the results obtained on the mutagenic properties of these two materials also apply to 4 Seasons. Polymerized Tetric specimens were extracted at 37 °C in water or DMSO for 30 days. The extracts were examined using a Salmonella typhimurium reverse mutation assay (Ames Test). This test showed that Tetric is not mutagenic [5]. An umu-test on Tetric Ceram confirmed these results. This test was also conducted with Salmonella typhimurium [6] and the extracts of Tetric Ceram were also negative in the Salmonella typhimurium reverse mutation assay [7]. In view of these results, we can conclude that 4 Seasons does not have any mutagenic potential.

5.4 Irritation and sensitization Like all light-curing dental materials, 4 Seasons contains methacrylates. If uncured, methacrylates may have a slightly irritating effect. In addition, methacrylates may lead to sensitization and allergic reactions, such as contact dermatitis, in predisposed individuals. The risk of allergies can be minimized by choosing a working technique that forestalls any direct or indirect skin contact.

15

4 Seasons®

5.5 Conclusion Studies on the toxicology of dental materials that contain similar ingredients as 4 Seasons show that, according to the current level of knowledge, 4 Seasons does not pose a health risk to users or patients, with the exception of possible allergic reactions in predisposed individuals.

5.6 Literature on toxicology [1] Acute Oral Toxicity (LD50) Study with Ytterbium-trifluoride, anhydrous in Rats. RCC Project 048881.

July 1985.

[2] Certificate – Determination of radioactivity. RCC Project 045224. February 1985.

[3] Schmalz G (1998) The biocompatibility of non-amalgam dental filling materials.

Eur. J. Oral. Sci. 106:696-706.

[4] Cytotoxicity test in vitro: Agar overlay assay. RCC Project 319926. March 1992.

[5] Salmonella typhimurium reverse mutation assay. CCR Project 314908, December 1992.

[6] Mutagenitätstest: Prüfung von Tetric®Ceram im umu-Test nach DIN 38 415-3. G. Leyhausen, Medizinische Universität Hannover, Interner Bericht. Dezember 1996.

[7] Salmonella Typhimurium Reverse Mutation Assay. CCR Project 563300. August 1996.

6. Literature Eisenmann DR (1998). Enamel structure. In: Oral Histology. Development, Structure and Function.

AR Ten Cate editor. St. Louis: Mosby, pp. 218-235.

Fernandez CP, Chevitarese O (1991). The orientation and direction of rods in dental enamel. J. Prosthet.

Dent. 65:793-800.

Garberoglio R, Brännström M (1976). Scanning electron microscopic investigation of human dentinal tubules.

Arch Oral Biol 21:355-362.

Hasegawa A, Ikeda I, Kawaguchi S (2000). Color and translucency of in vivo natural central incisors.

The Journal of Prosthetic Dentistry 83:418-423.

Krejci I, Stavridakis M (2001). Marginal adaptation of class IV composites before and after loading. JDR 80:590.

Schroeder HE (1991). Oral Structural Biology New York: Thieme. ten Bosch JJ, Coops JC (1995). Tooth color and reflectance as related to light scattering and enamel hardness.

JDR 74:374-380.

Torneck CD (1998). Dentin pulp complex. In: Oral Histology. Development, Structure and Function.

AR Ten Cate editor. St. Louis: Mosby, pp. 150-196.

16

Scientific Profile

This documentation contains an overview of internal and external scientific data (information). The documentation and the corresponding information have been prepared exclusively for in-house use and for the information of external partners of Ivoclar Vivadent AG. They are not intended for any other purpose.

Although we assume that the information complies with the latest standard of technology, we did not check all of them and may thus not assume any responsibility for their accuracy, truthfulness, or reliability. Liability cannot be assumed for the use of this information, even if we obtain contrary information. The information is used at the sole risk of the reader. Information is made available 'as received' without explicit or implied warranty regarding suitability (without reservation) for any specific purpose.

The information is made available free of charge. Ivoclar and its partners cannot be held accountable for any direct, indirect, immediate, or specific damage (including but not exclusively damage resulting from lost information, loss of use, or costs resulting from gathering comparable information), or for penal damages, which result from the use or failure to use this information, even if we or our representatives were informed about the possibility of such damage.

Ivoclar Vivadent AG Research and Development Scientific Service Bendererstrasse 2 FL - 9494 Schaan Liechtenstein Content: Edition:

Dr. Urs Lendenmann May 2003

17

4 Seasons速

18

Scientific Profile

19

4 Seasons, Artemis, Excite, AdheSE, Tetric and Tetric Flow are registered trademarks of Ivoclar Vivadent, Inc. All other products mentioned are not registered trademarks of Ivoclar Vivadent, Inc. Š Copyright 2003 Ivoclar Vivadent, Inc. REV. 05/2003

575363