Over the next few months Dr. John Carson and I will look at a few key factors in evaluating different composites. This will be done in an opinion/second-opinion format. John will be giving the second opinion in this article.
In the first of this series, I looked at Venus Diamond by Heraeus Kulzer versus Sonicfill 2 by Kerr. I looked at the compressive strength, adaptation and handling, translucency, flowability, shrinkage, polishability, and overall ease of use.
Venus diamond is a nanohybrid composite available in 23 shades. Sonicfill 2 is a bulk-fill composite activated by the vibratory action of a handpiece and is available in four shades. These two composite materials were evaluated for Class II composite placement.
Compressive strength: The compressive strength is important when placing posterior composites in high-function areas that must be able to withstand heavy occlusal forces. The compressive strength of Venus Diamond is listed on their website, and is 332 MPa. Although no information on the compressive strength was directly listed on Kerr's website, studies have shown it to be between 254 MPa (Sonicfill 1) and 316.596 ± 22.23 MPa. Both are adequate for posterior composite strength and durability, but Venus Diamond has a higher compressive strength.
Adaptation and handling: This is based solely on use in my hand. The Venus Diamond is a thick composite that doesn't easily adapt to the walls of a deeper preparation. I use titanium-coated instruments by Hu-Friedy and found the material to be sticky and difficult to place. I found the difficulty of placement increased with darker shades, which is to be expected, but the increase was more noticeable than other composites I've worked with. I found that placing the box, a second layer, and a thin final layer for carving anatomy was easiest. Final anatomy necessitated finishing and polishing. Radiographically, I was more likely to have a small void at the outermost portion of the box due to inadequate condensing. I felt more comfortable with adaptability when a thin flowable layer was placed on the pulpal floor prior to placing Venus Diamond.
Sonicfill 2 has a steeper learning curve because it handles unlike any other composite I've worked with. That being said, once I was able to adapt to the timing of the transition from a very malleable composite to a more rigid state prior to final curing, it was easy to work with. The adaptation is exceptional and feels more like a flowable composite at the very early stages of placement. I did not find it sticking to my instruments, and it was very carvable in the later stages of placement, which allowed for minimal finishing. Because it is a highly translucent material, it can be cured reliably up to 5 mm deep, so only one layer was placed.
Translucency: Venus Diamond was a fairly opaque material, but because there are a plethora of shades, I found there to be adequate options to select one that blends nicely with the surrounding tooth structure. Because the material is less translucent than Sonicfill, it had improved esthetics over Sonicfill when the remaining tooth structure presented with amalgam staining. It was able to adequately block out stains so that the margins blended fairly well into the surrounding tooth structure.
Sonicfill is a highly translucent material, which is one of the best and worst properties in my opinion. Because it is so translucent, you can use very few shades and have them blend seamlessly into many different teeth. I used A3 on almost every restoration placed, and they all blended extremely well. Because of the translucency, you can cure a deeper amount of material reliably as well. The translucency can be difficult when you are replacing an amalgam restoration. Even when the stain is a few millimeters below the surface of the prep, it is very apparent at the final cure. I overcame this difficulty by using a flowable opaquer on the pulpal floor when indicated, and the results were excellent. This does add an additional step to the process, however, and minimizes the benefit of one-layer placement.
Flowability: Venus Diamond is not a flowable material to work with. You have to adequately condense the material to feel confident you have achieved the necessary adaptation.
Sonicfill is very flowable in the beginning stages upon placement, and becomes less flowable as you work with it.
Shrinkage: Venus Diamond has 1.5% shrinkage versus Sonicfill's 1.88%. Both are very low shrinkage percentages.
Polishability: Both materials were highly polishable. On initial polish, Sonicfill 2 had a glossier, smoother appearance. On patient recall, I found that Venus Diamond looked the same as when placed, whereas the Sonicfill 2 looked similar to Venus Diamond and had lost the additional glossy finish it had on the day of placement.
Overall Ease of Use: Overall, Sonicfill 2 was easier to use after you overcame the learning curve. I can see first-time users getting frustrated with Sonicfill 2 during the first few placements, but after mastering the timing, it is extremely user-friendly. Venus Diamond is typical of a nanohybrid, and adaptability is a real concern. It is not as user friendly, but the learning curve is not as steep if you've placed other nanohybrids.
I would choose to have Sonicfill 2 in my armamentarium for Class II composites based on its ease of use. It can be placed in one layer, it is easy to manipulate, and one or two shades will match most teeth exceptionally well. There aren't many products that you can limit to that few shades and be happy with the result routinely! It's nice to have a nanohybrid when you do need a unique shade (and Venus Diamond has 23 options). While I wouldn't choose Sonicfill for anterior placement, Venus Diamond can be used for both.
The Second Opinion by Dr. John Carson
While Courtney offered excellent points and I agree with her on much of what she said, there are few items in which I will offer a different opinion. But let's start with the points we agree on.
For sure I agree that Sonicfill 2 is way more flowable and easy to adapt. Additionally, I agree that Sonicfill 2 is way more translucent, which is great for blending in teeth that are not discolored; however, when you do have discolored teeth, Venus Diamond does a better job at masking the dark colors, particularly if you are not going to use an opaquer with Sonicfill 2. I also agree on the polishability of the two materials.
Where I do disagree is on the point made about the learning curve. For me, there was nearly zero learning curve. I will also add that at times I find both materials wanting to stick, but I use stainless instruments; that being said, I see this way more with Venus Diamond. When sticking does occur does occur, I find a small amount of flowable composite or bonding resin on my instrument really helps if sticking is an issue. For me I tend to use flowable when using Venus Diamond as I already have it out to place a thin base coat as Courtney described. When I am using Sonicfill 2, which is most of the time in the posterior, I tend to use a bonding agent since I don't already have flowable out.
In closing, for me Sonicfill 2 is my go-to composite in the posterior, but there are times when I want or need a more conventional composite so I choose to have both available. Yes, I could get by with just a conventional composite like Venus Diamond, but I like working with Sonicfill 2 in the posterior way more – for me it is much more efficient. While I choose to have both on hand, if you only want to stock one composite for everything, Venus Diamond could fit the bill while Sonicfill 2 would not.
Courtney Lavigne, D.M.D., Spear Visiting Faculty and Contributing Author - http://www.courtneylavigne.com
John R. Carson, D.D.S., P.C., Spear Visiting Faculty and Contributing Author - www.johncarsondds.com
Didem A, Gozde Y, Nurhan Ö. Comparative Mechanical Properties of Bulk-Fill Resins. Open Journal of Composite Materials OJCM. 2014;04(02):117-121.