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Nobel Biocare Global Symposium 6 interview by Nobel Biocare n A new study conducted by leading mate- rials scientist Prof. J. Robert Kelly has con- firmed that not all dental implant resto- rations are created equal. In this interview, Kelly discusses the research, which has very recently been published in the International Journal of Oral and Maxillofacial Implants.1 The findings make for positive reading for NobelProcera customers. Nobel Biocare News: Your latest research tested the fatigue behavior of zirconia im- plant abutments from four major manufac- turers. What led you to take this approach? Prof.J.Robert Kelly: We wanted to study commercial products not in order to make commercial comparisons, but to study realis- tic products. Our goal was to look for pro- cessing problems and design issues, so it made sense to see what would happen with products on the market. We selected Strau- mann Bone Level (BL) Implants as our refer- ence and the study received funding from the ITI Foundation. Our search for comparison third-party abutments for the BL implants led us to abutments from NobelProcera and Glidewell—for BL implants these two manu- facturers only produce hybrid zirconia abut- ments that have a titanium insert interface to the implant—and the available abutments from Astra and Straumann that are fully zirconia. What was your methodology for testing these products? For the first phase, we first took six of the abutments in each of the four groups and tested them with repeated loads of 200 N. We chose 200 N for the accelerated aging based on our previous work. We did not want to break the implants, so we thought that was a fair load to start with. The results then allowed us to design the second phase, by determining the loads that we would use in testing with another 12 implants. However, by the time we received the data from the first phase, we were as- tounded. There were clearly significant dif- ferences between manufacturers in each of the categories. This was subsequently veri- fied in full-sample testing. You found that the NobelProcera product outperformed the other abutments in this test significantly. Yes, absolutely. While we had to re- duce the load with some of the other abut- ments, with the NobelProcera product, we ran out (no fractures at 25 million cycles), so the load had to keep going higher and higher. How would you explain this apparent weak- ness of the other abutments? The vast differences were unexpected, as the macro-designs are similar across the manufacturers. To help determine why we were seeing such varied results, I asked my colleague Dr. Isabelle Denry to do scanning electron microscopy analyses. Looking at one of the poorest performing abutments in the study, she identified that the weakness was the result of damage arising from the manufacturing process—subsurface grinding damage, large cracks, inhomogeneous crys- tals and a diffuse layer of porosity. From this, it was evident that manufacturer matters. There are many reports of issues caused by third-party abutments being used with a system that they were not designed for. Considering that manufacturer matters, do you advocate using only authentic compo- nents? In general, I advise against using lower cost third-party abutments. There is too much to lose. From what we have seen over the years, the quality of the materials is in- ferior, and the outcome has such a high value: the patient has very high expecta- tions of the clinician—why would you risk that to save $100? Considering that the NobelProcera abutment for BL implants outperformed all of the others, what are your thoughts? NobelProcera is produced in a high- quality process, since Nobel Biocare fabri- cates components that are designed, tested and then verified for the BL implant sys- tem. 7 Reference: 1. Kelly, J.R. & Rungruanganunt, P., “Fatigue behavior of computer-aided design/computer-assisted manufacture ceramic abutments as a function of design and ceramics processing”, International Journal of Oral and Maxillo- facial Implants, 31/3 (2016), 601–9. Zirconia abutments with titanium base Full zirconia abutments NobelProcera Glidewell Straumann® Atlantis™ 1 sextillion cycles Extrapolated cycles for 10% failure at 70N (expected clinical load) 1 million cycles 30 million cycles 20 million cycles 0 107 1014 1021 Visit nobelbiocare.com/nobelprocera Science First Strong NobelProcera® Abutments “Manufacturer matters”: the four abutments look very similar in clinical examination, DWVFKHHGTGFUKIPKƂECPVN[KPRGTHQTOCPEGKPFKECVKPIVJGKORCEVQHFGUKIPCPF RTQFWEVKQPOGVJQF -GNN[,44WPITWCPICPWPV2(CVKIWG$GJCXKQTQH%QORWVGT#KFGF&GUKIP%QORWVGT#UUKUVGF/CPWHCEVWTG%GTCOKE#DWVOGPVUCUC(WPEVKQPQH &GUKIPCPF%GTCOKEU2TQEGUUKPI+PV,1TCN/CZKNNQHCE+ORNCPVU +PXKVTQHCVKIWGVGUVQH %#&%#/|CDWVOGPVU #DWVOGPVU PGCEJHTQO#VNCPVKUv)NKFGYGNN 0QDGN|$KQECTGCPF|5VTCWOCPPCNNVGUVGFQP 5VTCWOCPP$QPG.GXGNKORNCPVU 5 Prof. J. Robert Kelly 5 Zirconia abutment D1. Manufacturer matters when it comes to ceramic abutments An interview with Prof. J. Robert Kelly 0107