2. What is the polymerisation shrinkage of SDR?
3.5%. The rate of volume shrinkage of SDR is considered to be average in relation to other flowable and universal composites.
3. What is the compressive strength of SDR?
4. What is the flexural strength of SDR?
5. What is the average particle size of SDR?
6. What is the filler percentage of SDR by weight and by volume?
68% filled by weight and 45% filled by volume.
7. What is the shelf life of SDR?
8. What is the radiopacity of SDR?
9. Does SDR release fluoride?
Yes, SDR can release detectable fluoride for 15 continuous weeks.
The accumulated total release is 2.971 µg/cm2.
The average fluoride release per week is 0.198µg/cm2/week.
10. What is the Barcol or Shore hardness value of SDR?
Medium Barcol hardness = 98.
Hard Barcol hardness = 64.
11. Is the cure time of SDR the same for halogen and LED lights?
Yes, the cure time is 20 seconds with a minimum output of 550mW/cm2.
12. How many shades of SDR are available?
One universal shade.
13. Is SDR a stackable flowable?
SDR has a unique self-levelling handling which allows the material to adapt to the cavity. It is not considered to be “stackable”.
14. Does SDR contain nano-technology?
Yes, it contains 2-3% nanofiller by weight.
15. Is SDR compatible with other composites?
SDR is chemically compatible with all conventional methacrylate-based composites.
16. Is the nanofiller of SDR comparable to that in CeramX®?
SDR has a silica nanofiller whilst CeramX has polysiloxane modified nano-particles.
17. What is the chemistry of SDR?
Low stress methacrylate resin with hybrid glass fillers.
18. Is SDR compatible with all bonding agents?
SDR is chemically compatible with methacrylate-based adhesives.
19. What is the diameter of the Compula® Tip?
0.6mm inner diameter x 0.9mm outer diameter (20 gauge).
20. What does SDR stand for?
Smart Dentin Replacement.
21. Does layering a regular composite compensate for shrinkage stress?
The layering technique does compensate for stress to a certain degree. However, even when applying a sophisticated layering technique, methacrylate-based composites will produce a significantly higher polymerisation stress compared to the SDR material.
22. Does SDR need to be capped with a conventional composite in all cavity classes?
SDR is indicated for class I and class II restorations with the use of a methacrylate-based universal composite as a capping agent. It can be used without capping in deciduous teeth and in small, conservative class I restorations.
23. Will SDR work on air abrasion preparations? Does SDR need to be capped with another composite to achieve the required hardness? If not, how does the long-term wear of SDR compare to conventional flowables?
SDR is not indicated for air abrasion preparations. Just like traditional flowable composites, SDR is not indicated for occlusal stress bearing indications and would require another composite to be placed on top to provide the strength and wear needed for occlusal areas. In-vitro wear studies have shown that SDR performs comparably to conventional flowables.
24. Flowable composites have too much shrinkage and are too weak. Why would I use SDR?
Shrinkage is not the destructive feature in composites; it is the stress that is exerted on the surrounding tooth structure. SDR has shrinkage in the range of traditional flowable/universal composites, but its stress is 60% less compared to flowables1. According to top clinicians and academics, polymerisation stress is a leading cause of bond failures, enamel fracture, post-op sensitivity, secondary caries and marginal staining3. Because of the low stress of SDR, it can be placed in bulk, up to 4mm increments, which no conventional flowable can do because of their high stress values, resulting in a placement time saving of up to 40%1.
25. Amalgam adapts to the preparation in the posterior and has no shrinkage. Why would I not use amalgam?
SDR offers a time-saving advantage to both the dentist and the patient and provides an aesthetically pleasing tooth coloured restoration.
26. Why would I use SDR versus EsthetX® flow composite or Sectrum®TPH®3 flow composite?
SDR can be placed in 4mm bulk increments and possesses unique self-levelling and cavity adaptation features. EsthetX flow and Spectrum TPH3 flow composites are limited to only a 2mm depth of cure so they cannot be placed in bulk and offer time savings in posterior restorations in the way that SDR can. They also do not offer the low shrinkage stress like SDR.
27. How does the radiopacity and shrinkage of SDR compare to other flowable and universal hybrid composites?
SDR has its own unique balance of properties compared to flowable and universal composites. The radiopacity is 2.2mm Al which is higher than most restoratives and natural enamel (2.0mm Al) and dentin (1.0mm Al). Its physical properties are comparable to currently marketed flowable composites but with a 60% lower stress1.
28. How does the strength of just lining the box with SDR on a class I cavity and placing a universal material for the remainder of the prep compare to placing it in bulk and capping it with a universal composite?
Either method will provide an acceptable restoration with the same longevity, but the time savings and improved cavity adaption will be achieved when using the material in bulk increments.
29. What is the difference between SDR and QuiXfil®?
SDR is positioned as a posterior composite material with flow like consistency. This consistency provides excellent adaptation to the tooth surface by self-levelling. SDR needs to be capped with a universal composite. It is therefore the ideal material for conservative users of universal composites who desire easier handling for improved and faster placement of posteriors. QuiXfil has a higher consistency (does not self-level) and does not need to be capped with a conventional composite.
30. SDR has a flow like consistency. Will it flow beyond a matrix band?
Assuming that the matrix band is placed correctly, no more than creamy composites1.
31. Does SDR always need to be capped with a conventional composite in the posterior?
Yes, apart from when using in small, conservative class I restorations and in deciduous teeth.
32. SDR has a flow like consistency, how can a contact point be created in the posterior?
In the same way that the contact point is created with regular composites. That is, the matrix band has to be placed in intimate contact with the adjacent tooth. The vast majority of composites will not displace the matrix and therefore will not aid contact point creation.
33. What is the basic mechanism of the Polymerisation Modulator in SDR?
With SDR Technology, a Polymerisation Modulator is chemically embedded in the polymerisable resin backbone. Based on scientific evidence gathered to date, the Polymerisation Modulator synergistically interacts with the camphorquinone photo-initiator to result in slower modulus development (=controlled polymerisation) allowing for stress reduction without a reduction in the polymerisation rate or conversion. Essentially, the entire radical photo-polymerisation process is mediated by the Polymerisation Modulator specially built into the SDR resin which allows more linear/branching chain propagation without much cross-linking, and hence slower modulus development. This modulating effect allows extended polymerisation without a sudden increase in cross-link density. Thus, the extended “curing phase” not only maximises the overall degree of conversion, but also minimises the polymerisation stress resulting in the cured phase (Source: Technical Manual and Fact File).
34. Will the Polymerisation Modulator open its chemical structure as the ordinary resin shrinks?
No, it will control the modulus build-up and the cross-link formation.
35. What is the wear of SDR in the area of approximal contact points?
DENTSPLY used a 2 body wear test to measure the wear of SDR on approximal contact points. The result shows that the wear is comparable with that of EsthetX HD, Heliomolar4
and Gradia Direct5
2-body wear tests generally measure the volumetric wear resulting from the contact between two solid bodies. It is thought to have clinical significance/relevance since it emulates proximal surface wear in class II composite restorations.
36. How can dark dentin be masked using SDR for posterior restorations?
In such a case, DENTSPLY recommends the use of a body/opaque shade as the capping agent in 2mm increments.
37. Is SDR only suitable for large cavities?
No, the Compula Tip allows for the very precise placement of SDR especially in smaller cavities that are difficult to reach with a method using layered composite.
38. Is SDR recommended for coronal closure?
Yes, a coronal closure is nothing but a large class I or II restoration, which requires a lot of material. The conventional layering technique is more time consuming and has the potential of generating more shrinkage stress, since shrinkage and stress are proportional to volume. SDR is therefore very helpful in these situations.
39. What is the advantage of using SDR over a Glass Ionomer (GI) employing the ‘sandwich technique’?
In general, a sandwich technique with a GI is considered by many to be old fashioned. Composites offer more stability, longevity and better dentin adhesion. SDR is easier and faster to use than a GI. A dentist has to wait until the GI is set before the capping composite can be placed on top and the GI also needs to be etched before the composite is placed. A GI has no flow like and self-levelling capabilities like SDR and therefore requires more manual adaptation work by the dentist. There is also the potential for more voids and bubbles with a GI.
40. What is the content of SDR per Compula?
0.25g or 0.13ml.
41. What is the VITA®6 shade of SDR?
SDR comes in a universal shade. If it has to be related to the VITA shade guide, it would be lighter and more translucent than the typical B1 composite.
42. How can excess of SDR be removed?
At the completion of dispensing, wipe the Compula Tip against the cavity wall while withdrawing from the operative field. In case of overfill or excess on occlusal margins, use a flocked applicator tip slightly moistened with residual adhesive to remove excess.
43. How long does it take until SDR fully self-levels in a mid-sized cavity?
Less than 10 seconds at mouth temperature (±32 – 36°C).
44. Is SDR a low shrink material?
SDR has an average volume shrinkage – it is not a low shrink material. The unique feature of SDR is the low polymerisation stress that SDR exhibits after curing. The destructive force in a composite restoration is not the volume shrinkage – this is compensated by the adhesive – it is the shrinkage stress. SDR contains a unique and patented chemistry (the Polymerisation Modulator) that leads to a controlled network formation when the material is light cured. This relaxed network formation leads to much lower shrinkage stress of SDR compared to other materials used for posterior restorations. This feature is the reason why SDR can be applied in bulk.
45. Is there a minimum requirement for the thickness of the cap made with the conventional composite?
DENTSPLY recommend covering the whole restoration made with SDR with about 2mm of capping material. There may be regions where the cap has a higher thickness. For example, when stained dentin has to be masked, it is necessary to have a cap layer that is thick enough to cover the dark shade that shows through SDR.
46. Is the curing time of SDR reduced when using a high energy light (i.e. plasma light)?
DENTSPLY believe that faster cure time results in higher shrinkage stress. Testing on SDR has not been completed with a high energy output curing light. In some cases, high energy output curing lights do not have a high curing efficiency – curing time is not shortened and more heat is generated which increases the risk of heat induced pulpal injury. DENTSPLY does not recommend using a curing light with power over 1600mW/cm2 for SDR. If a dentist wishes to test the curing efficiency of their lamp, they can use the iCure device which can be provided by DENTSPLY.
47. What is the pH of SDR?
It is 6.7 (nearly neutral).
48. What is the density of SDR?
At 25°C, the density of cured SDR is 2.00g/cm3 and the density of uncured SDR is 1.93g/cm3.
49. If a dentist applies too much SDR and light cures it, leaving no space for the composite layer, is it possible to reduce the SDR layer by grinding it? Is a bond step needed?
DENTSPLY recommend the CEBL technique.
C: Cut back by grinding
E: Etch with DeTrey® Conditioner 36 to clean the surface and etch the enamel
B: Apply XP BOND
L: Layer the capping composite as required
DENTSPLY can only recommend an etch&rise technique for the bonding stage as the self-etch technique has not been tested.
50. How is SDR classified in terms of the particle size, is it a hybrid or micro hybrid?
Based on the classification of dental composites, SDR should belong to hybrids. (Page 92 of
Jack Ferracane, Materials in Dentistry, 2nd, Lippincott Williams & Wilkins, 2001).
51. Does SDR contain epoxy resin?
52. Is SDR compatible with CoreX™-flow?
Yes, it is compatible and no additional etching or bonding is needed as CoreX-flow is methacrylate-based.
53. Is it possible to cap SDR with Dyract®or Dyract XP?
Yes, SDR can be capped with all methacrylate-based composite materials (compomer, composite and ormocer).
54. What is the co-efficient of expansion of SDR, and if available, how does it compare to other competitors?
DENTSPLY does not have the data of thermal expansion coefficient for SDR. The thermal expansion coefficient is mainly determined by filler loading. The higher the filler loading, the lower the thermal expansion coefficient is. DENTSPLY expect that the thermal expansion coefficient of SDR is between regular universal composites and flowable composites, in the range of 30-50 x 10-6/C. This value is higher than tooth structure (10-20 x 10-6/C).
1 Data on file
2 Filtek Supreme XT Flow, Tetric Evo Flow, x-tra Base, Herculite XRV, Filtek Supreme XT, Grandio, TEC Bulk Fill, Venus Bulk Fill, Filtek Silorane, Tetric Evo Ceram and Venus Diamond are not registered trademarks of DENTSPLY International, Inc.
3 Dr. Joe Blaes, Dental Economics: June 2008; JOHN R. CONDON, B.S. and JACK L. FERRACANE, PH.D.J Am Dent Assoc, Vol 131, No 4, 497-503; JL Ferracane, Operative Dentistry, 2008, 33-3, 247-257; Gordon J. Christensen, DDS, MSD, PhD J Am Dent Assoc, Vol 138, No 11, 1487-1489
4 Heliomolar is a registered trademark of Ivoclar Vivadent Limited
5 Gradia Direct is a registered trademark of GC Corporation
6 VITA is a registered trademark of Vita Zahnfabrik, H. Rauter GmbH & Co