SLActive a new standard in implant dentistry?

slactiveLast week Straumann provided a research update on its third-generation dental implant surface technology, SLActive. According to Straumann, as the first chemically-active dental implant surface, SLActive accelerates the osseointegration process, enhances predictability in every indication, and reduces healing times, from 6 weeks to 3 weeks.

Studies you ask? The company commented in their latest press release:
“In all, more than 14 studies on SLActive have been initiated, with particular focus on the initial healing processes. These add to the existing body of scientific data on SLA that supports the new surface.

The development program and distinct clinical benefits of SLActive were also reviewed at the AO. The new surface has shown outstanding clinical results and predictability. For example, in the multicenter clinical trial initiated in 2004 and involving 19 centers worldwide, more than 400 SLActive dental implants have been placed with a survival rate of 98%. This is remarkable in view of the extremely challenging treatment protocols involving immediate function/loading (211 dental implants) or early loading (190 dental implants).

To add further to the body of peer-reviewed published scientific evidence supporting SLActive, the results of a significant preclinical trial are in the process of being accepted for publication in a leading peer-reviewed journal. The findings demonstrate that osseointegration occurred up to twice as fast with the SLActive surface by comparison with the current gold-standard SLA surface.

These are pretty hefty claims. Does anybody have any experiences to share with SLActive to shed some light on these results? Is this new dental implant surface technology truly going to set a new standard in implant dentistry?

41 thoughts on “SLActive a new standard in implant dentistry?

  1. I heard that SLA active is a copy of the Friadent surface that has been around for a few years and it is just stored in saline solution.

  2. Doesn’t it take 40 to 50 weeks for mineralzation to take place, for the human body to heal?

  3. While at the AO meeting in Seattle, I heard a lecture by Dr. Wilson, a Periodontist from Tx. He reported on placement of about 300 older Straumann SLA implants in immediate extraction sockets, free-standing, followed by immediate loading. He had 98% success. I asked him from the audience..”do you think you would have obtained 99% success if you used the new SLActive surface.” His answer was what you would expect from such a rhetoric questions.. “I’m not going to answer that question.” Today, immediate load is a clinical reality in good quality bone with any rough surface, screw implant. If the bone quality or the initial stability is compromised, then an 8-12 week unloaded healing period is advised. To tempt the implant Gods by loading an implant in 3-4 weeks in soft bone because a study in some rabbit tibia showed a 20% higher torque removal or % of bone contact at 3 weeks vs 4weeks, is unwise. A study demonstrating high success with SLActive implants loaded at 3-4 weeks, give Wilson’s results with SLA surface implants loaded immediately, does not prove “faster integration” or any clincial advantages. It remains unproven if there would be any statistically significant improvement with SLActive vs SLA, or for that matter, any difference if the implants were loaded in 3-4 weeks or loaded immediately.

  4. How does the new SLA Active surface compare with the Astra Tech Flouride modified surface.

    Which is better.

  5. Remember the old Integral Implants from the ’80s? Same story, different surface. The body heals, not the implant, at least not yet.

  6. Interesting that the only posting referring to marketing is from “anonymous”. Bet that was from a Straumann Salesperson or “oppinion leader.” I just voiced my oppinion for what it is worth. It is Straumann who is trying to justify an extra $50 dollars or so for its wet surface on marketing claims of 2X faster osseointegration. That isn’t even what the studies show that are the basis for this claim. They show that the low point of stability is reached in the 3rd week vs the 4th week on animal studies. That is why it has no clinical signficance to immediate load implants that either work or fail in the first week. Nor does it have any significance to implants that are left unloaded for 8 weeks or longer. So for those of you who want to load your implants in 3 weeks rather than immediately, or rather than wait 8 weeks, maybe there is some theoretical advantage, but how would you prove that that implant could not have been loaded immediately and still have it be successful?

  7. It seems that the closer we get to regular timing of C&B is s good thing.
    Faster turnaround is more profit and predictibility with higher risk patients seems a good thing. When a product puts back the control into the clinicians hands, like the haeling process, it gives us security. If the implant is ususlly less stable in the 2-3 week, but now it is not, then the patient dosent have to worry about not haveing to bite on it and dislodge it. It is this time framr that patients seem to forget that they have a temp or implant in place and that is when bad things happen like temps breaking and the like. JMO.

  8. Jerry, back in Palm Springs AO Meeting you did receive the same question you are asking now, when you came up with the implant with three surface characteristics…..

    What is the point here?

    As a company itself I

  9. The point about claims of increased stability at 3 weeks vs 4 weeks is that it is impossible to prove if it has any clinical significance because the same implant most likely could have addequate stability at day one to be immediately loaded. With immediate load implants, if we overload them, the failure will appear in the first week from my experience. Maybe this means that the type of animal studies being conducted to show less of a drop in stability at 3 weeks was never the type of bone that one would clinically use for immediate loading. I do beleive that Straumann is far more concerned about credible research than Nobel but when the purpose of the research is to support the sale of a more expensive implant surface, it must be looked at critically and also from a practical standpoint – have they proven any clinical advantage or is the research just more marketing hype.

  10. I give credit to Straumann for bringing a product to market that actually has some research, not marketing, behind it. I assume with research there is cost. If the product can increase osseointegration rates and provide a better treatment, its worth the cost.

  11. Another anonymous posting, probably from a Straumann employee or paid oppinion leader. Implant companies must differentiate their products, especially if they are demanding premium prices. Product development and supporting research deserve praise when the research proves that the product does, “provide a better treatment.” The operative word in your email is “If.” A few animal studies and some clever marketing claims may influence some dentists to pay more for a product, but that does not make it “worth the cost.”

  12. As an end user and not a researcher this discussion is frustrating. I agree with Jerry’s asking for more info and certainly would like to see under the shroud of anonymous. I will however do my best to look up the references on Straumann’s studies that these claims are based on.

  13. Under the principal parameter in the world to measure a doctor…(money)…dr. Niznick is the most incident and relevant person.We ALL look for the same!!!!!!.
    As clinicia I do need research behind products to place them.Unfortunately Straumann research in that fiels are ongoing studies, that is why they are not talking to loud.I remember when Straumann people claimed Lazzara a remark”*Research on file” when they came out with Osseotite and Straumann have had long evidence on SLA surface at that time….It is a game and probably dr. Niznick will be the winner again. We need to learn more from successfully people and not from hired or paid doctors from companies!
    Albert

  14. ANSWER TO QUESTION POSTED BY JOHN, May 3, 2006.
    How does the new SLA Active surface compare with the Astra Tech Fluoride modified surface? Which is better?
    ANSWER: You could add to this question, Nobel Biocare’s TiUnite and Friadent/Plus Surfaces, all four companies claiming faster osseointegration, and never come up with the answer of which is best because with >95% success with all rough surfaced, titanium screw implants dental implants, it would be impossible to devise a clinical study to prove a statistically significant difference. Four other companies also provide a rough surface but do not make claims of superiority, relying on other factors or features to differentiate their products. Zimmer (MTX -Micro-Texture), Lifecore (RBM), BioHorizons (RBM – Resorbable Blast Media) and Implant Direct (SBM – Soluble Blast media) all use a rough surface created by blasting with soluble HA particles. This is the same surface, used on the Paragon Implants throughout the 1990’s. I selected it again because of its long-time, proven clinical success. Also, unlike Straumann’s SLA/SLActive, Friadent/Plus or Astra’s OsseoSpeed, SBM does not require a secondary acid etching process to remove Aluminum Oxide or Titanium Oxide blasting particles, and therefore avoids additional rounding of the threads and cutting grooves.
    Implant Innovations’ Osseotite surface is the only one using acid etching alone to modify the machined surface of the implant, and that results in a surface that is relatively smooth compared to all the others, when measuring peak-to-valley surface irregularities.
    TiUnite, an anodizing process developed in Germany long before Nobel claimed it invented it (I think Nobel paid a license fee), consists of tubular projections with smooth areas in between. There is no proof, or even any reason to think this would be any better than an even rough texture created by blast particles. Nobel now extends this surface into the soft tissue area, claiming that the rough surface improves “soft tissue integration.” There is a lot of controversy (see published ML reports on “Controversies” section of Implant Direct’s web site) created by Drs. Albrektsson and Sennerby from Gothenburg University, claiming excessive bone loss with Nobel’s one-piece Nobel Direct implants, some of which have an extended rough surface. This is a good example of where the marketing got ahead of the research.
    And then to round out the surface discussion, lets not forget the Branemark Machined Surface, which Nobel and Branemark patented in 1979. The Patent was eventually declared invalid by fraud on the US Patent Office, but only after Nobel sued a number of implant companies. Nobel ended up paying 3i $10M for anti-trust violations for pursuing a fraudulent patent. Any claims today of surface superiority by Nobel or any of the other major implant companies should be viewed in relationship to all the false claims of superiority that were associated with the Branemark “unique” machined surface that was considered the “gold standard” by some, only to find out that such a smooth surface had about a 10% higher failure rate in soft bone than rougher surfaces.
    A discussion of implant surfaces can not ignore HA Coating which proved to be significantly better in the VA studies of 2900 Paragon Implants when compared to acid etch surfaces. If that multi-center comparative study had used blasted surface vs an etched surface to compare to HA coated surfaces, the differences in clinical success would have been less dramatic if at all, but that research remains to be done. HA coating may be the only Osseo conductive rough surface. It is available today on the ScrewPlant (Implant Direct), Screw-Vent (Zimmer), Replace (Nobel Biocare) and very few other implants.
    Last and probably least is Innova’s Beaded surface, which like the obsolete TPS surfaces of Friadent and Straumann, can be a soft tissue problem if it becomes exposed to the oral environment.
    THE REAL ANSWER: Price, Prosthetics and Practicality are far better factors to differentiate implants than surface claims of the manufacturers.

  15. In Toronto, Dr. Cochrane, on behalf of Straumann, showed multiple studies of SLA vs. SLActive. The end result suggested you could load the implant 2 weeks earlier. As a periodontist, and I will stay anonymous, I would not suggest to my referral base to do this simply because 2 weeks really would not make a difference in the long run. I see no value in changing my treatment plan that has worked for me quite well. There is something to be said about conservatism.

  16. With Wilson, a Tx Periodontist reporting at the AO Seattle meeting, 98% success with SLA (old surface) ITI implants placed in extraction sockets and loaded immediately, was Cochrane suggesting that with SLActive, you could load the ITI implants two weeks earlier than the day of surgery…. now you see how ludicrous his claim would be. Nobel played on this at the AO meeting in Seatle. At their booth, and as you entered the convention center, they had large, back-lit charts showing ITI’s claims of loading the implant at 6-8 weeks with SLA surfce, and 3-4 weeks with SLActive surface, compared to Nobel’s implants on the chart showing loading in 0 weeks. i.e. immediate loading like so many other implants today with FDA approval to claim immediate load.

  17. The real benefit of the SLActive implant surface is that it accelerates osseointegration and achieves secondary stability sooner. This means that implants with the SLActive surface are stable earlier in the osseointegration process. Secondary stability ealier in the healing process is beneficial in every treatment plan, but especially in treatment plans incorporating immediate or early loading. All of the scientific evidence supporting SLActive reveals the same conclusion – with SLActive the process is happening faster than with SLA. It is clearly a better surface.

  18. I am one of the investigators involved in the above mentioned SLActive multicenter clinical trials.
    In my opinion the most relevant observation in this discussion is reputable implant companies searching for an improved surface, even though there are clearly many surfaces that are capable of predictable integration. Each of these companies deserve credit for their endeavours.
    SLActive is, however, supported by basic science and animal research, in addition to our clinical trials. This should be recognized for what it is – one of the positives for all that choose to use this implant. In conjunction with the implants versatility and restorability, these characteristics help us make this choice.
    I agree that there are many publications which support early and immediate loading of a range of implants. The key to me is in terminology. Osseointegration refers to an implant in contact with bone that is capable of supporting functional load to a predictable survival percentage. SLActive, in the studies to date, has proven capable of supporting functional load immediately (clinical trial) and at 21 days (our multicenter evaluation – results initially presented in Munich and Miami). Again, this is, at least to me, a positive.
    I would also like to clarify two issues. Firstly, accelerated time to load is only one factor that introduces increased risk to implant survival. As a prosthodontist it is my hope (and persponal opinion) that improved surfaces such as SLActive will reduce treatment risk in other patient groups – those with systemic disorders such as diabetes for instance. Or smokers? Secondly, SLActive gains it’s benefit not from being wet – rather from never being dry. This prevents hydrocarbon contamination and maintains the surface activity and hydrophilicity. Secondary atability is therefore initiated earlier, reducing the magnitude and time over which the reduced stability is observed. Simply wetting an already dry implant (even SLA) does nothing with regard to these properties. Therefore, while previous surfaces (particularly SLA) may share morphology, none to my knowledge share the chemical status of the SLActive surface.
    Lastly, I am glad that there are so many clinicians asking questions – this is inevitably better for the most important group in implant dentistry – the patients.

  19. The Saline packaging only protects what has been done in the manufacturing process. The Saline is not what makes SLActive hydrophylic or chemically active. As for qouting Nobel at the AO their critique of SLActive surface was to use their Immediate Function trademark claiming they are the only implant that has this available. Of course the trademark prevents other companies from using the phrase Immediate Function. Which is another way of saying immediate load. In the marketplace many clinicians misinterpret what is being said by their Nobel rep to mean that no other implant is approved by the FDA for Immediate Loading. I hope most people at the AO saw through that assessment and also wondered why Nobel was so worried that they dedicated their entire both to another company´s product. The SLA surface like Astra’s has a 6-8 week waiting period from implant placement to crown. The double acid etched 3i implant is 10 weeks. Tiunite from Nobel is 12 weeks. SLActive is 3-4 weeks which may not change the treatment protocol for all patients. But it certainly isn’t a bad thing and may provide the opportunity to expand treatment options.

  20. STATEMENT: SLActive, in the studies to date, has proven capable of supporting functional load immediately (clinical trial) and at 21 days (our multicenter evaluation – results initially presented in Munich and Miami). Again, this is, at least to me, a positive.
    NIZNICK COMMENT: Why is it positive? if an implant can be placed in functional loading immediatly, what would be so surprising that it can also successfully be loaded at 21 days?

    STATEMENT: As a prosthodontist it is my hope (and persponal opinion) that improved surfaces such as SLActive will reduce treatment risk in other patient groups – those with systemic disorders such as diabetes for instance. Or smokers?
    NIZNICK COMMENT: I would like to say that as a prosthodontist it is my hope (and personal opinion) that improved implants like I will be selling will cure systemic disorders such as diabetes for instance… or even cure smokers… well at least stop them from smoking!!!!

    STATEMENT:The real benefit of the SLActive implant surface is that it accelerates osseointegration and achieves secondary stability sooner. This means that implants with the SLActive surface are stable earlier in the osseointegration process.
    NIZNICK COMMENT: With 98% success on immediate load with SLA by Wilson… you obviously do not need secondary stabliity if you have primary (day one) stability.

    STATEMENT:I hope most people at the AO saw through that assessment and also wondered why Nobel was so worried that they dedicated their entire both to another company´s product.
    NIZNICK COMMENT: I thought Nobel was right on target with its marketing against Straumann’s claims at the AO meeting. Straumann’s marketing claims, repeated by the last anonymous author, is far more misleading:
    The SLA surface like Astra’s has a 6-8 week waiting period from implant placement to crown. The double acid etched 3i implant is 10 weeks. Tiunite from Nobel is 12 weeks. SLActive is 3-4 weeks which may not change the treatment protocol for all patients. But it certainly isn’t a bad thing and may provide the opportunity to expand treatment options.

    NIZNICK STATEMENT: None of these implants have any waiting period if the quality of the bone is good enough to immediate load the implant. Merely because somewhere in these companies’ marketing literature history, they gave a recommendation for a specific healing time, does not mean that that is when osseointegration will take place.

  21. Experts follow the scientific data. Osseo-integration is studied under three criteria
    Surface tests are
    1. Bone to implant contact
    2. Removal torque values
    3. Functional load with bone compression values
    SLActive seems to have higher test values than other implants.
    Follow the data is the mantra.
    If other companies can provide these three tests with supportive studies than its worth a look to compare.
    Faster integration toward these values will provide the operator with security which may have a price point that is higher. Conservative dentistry practices higher success with added security.
    SLActive provides this through science and thus the price premium is not an issue.
    Time will support this or not.
    Data will guide us along with clinicical success rates.
    Immediate load and fast healing are two differant concepts. Immediate load is high risk and fast healing (integration) is low risk.
    Yoyu can now increase the pool of patients with less risk it seems.
    Some people show up to flog the product. Some to share clinical success. Follow the data (not opinions)to success.
    Listen to mentors and ask where the data is.
    1.Removal torque tests
    2.Bone to implant contact
    3.Functional tests
    Practice the best dentistry.
    As it is said.
    I dont care what you know until I know that you care.

  22. STATEMENT: SLActive seems to have higher test values than other implants.
    NIZNICK’S COMMENT: Hire than what? As far as I can tell, it was just tested against SLA, just like Nobel tests TiUnite against machined surfaces.
    If Straumann wanted to demonstrate superiority, it could test its implants against TiUnite, SBM, HA, Osseospeed etc.

  23. As market leaders their task is to lead the market…what direction they lead is to be determined by the end users.

  24. And if Implant Direct wanted to show superiorty with SBM they wouldn’t have compared it against TPS, Machined, HA coated and only acid etched implants, which SLA is not? Since the process to produce an SLActive and SLA implant are the same,with the exception of the environment, comparative lit on SLA versus other surfaces would add value to this discussion.

    Waiting time to final crown is important information, as it sheds light on how quickly the body adapts bone to an implant to provide for Secondary Stability. Primary Stability is accomplished by shoving an implant into a hole in bone that is smaller than the size of the implant. If you have good Primary Stability studies from a variety of companies demonstrate that you can immediate load the site. Dr. Niznick focusing on this is like saying if your car works then you can drive it. But when you don’t have good bone and can not immediate load why wouldn’t you want to use an implant that provides for the fastest turnover to secondary stability? Why wouldn’t you want better bone to implant contact throughout the entire healing process? Doesn’t FDA approval for load times have value, or should we all rise up and demand that the FDA stop providing these kind of approvals to comapanies?

    Truth does not require a name to have value. The arguements against SLActive in these postings do more to enlighten us about what other companies are selling than what Straumann has created with this new surface.

  25. Nobel Claimed Immediate Funtion at the AO in all their discussions about SLActive. This is a phrase that they have Trademarked.

    Not all patients or locations in the mouth (Posterior Maxilla) have the bone quality for Immediate Load.

    Nobel question, “How many studies does SLActive have on Immediate Function” Nobel Answer, zero. Real question how many studies does any company, other than Nobel, have on Immediate Function? Answer: Zero as no other company can use the term Immediate Function. So Dr. Wilson has a 98% success rate on immediates with the SLA surface that is produced the same way as SLActive only SLActive is kept in a Nitrogen rich environment.

    Would Dr. Wilson Immediate load the SLActive implants two weeks before he placed them? I’m guessing NO as the crown would likely get in the way during surgery. Better questions might be “Have you used the new surface?” Have you expanded your protocols for immediate load or early load? If so have you maintained the same 98% success rate despite having a more aggressive protocol? I don’t know the answers to these questions but it would be a much more interesting discussion than hearing what other companies are saying about a product that they don’t appear to be able to copy.

  26. Response to Comment:
    And if Implant Direct wanted to show superiority with SBM they wouldn’t have compared it against TPS, Machined, HA coated and only acid etched implants, which SLA is not?
    Niznick Answer:
    When these tests were done in the mid-1990’s with Paragon Implant company’s SBM surface, which is the same surface being used by Implant Direct, BioHorizons, Zimmer and others today (HA Blast), SLA was not available for comparative testing. SLA was developed to overcome the soft tissue complications of exposed TPS. SLActive was developed to allow Straumann to raise its prices $50 per implant and to differentiate itself from other companies.
    A recent article by Shalabi in JOIR, April proved that inserting a tapered implant with SLA surface into an undersized socket, compared to the same implant into a fully prepared socket, resulted in significantly higher bone contact and torque removal. The tapered Screw-Vent from Zimmer, which I developed in 1999, the new Spectra-System Implants from Implant Direct all offer a soft bone and hard bone surgical protocol based on the diameter of the final drill used. The main advantage of a tapered implant is that if the socket is undersized, the narrow end can still start into the site, slowly expanding the soft bone as the implant self-taps its way into the bone. With type 1 and 2 bone, probably any implant can function with immediate load. With type 4 bone probably no implant would be successful with immediate load and waiting a full 3 months for mature healing would be prudent. This only leaves the relatively soft type 3 bone, and if the initial torque level of 35Ncm can be attained by placing a tapered implant into an undersized socket, then that implant can be immediately loaded also. Since the ITI implant is not tapered and does not offer a soft bone protocol for bone expansion as the implant is being seated, even if SLActive did speed healing to 3-4 weeks, that would be 3-4 weeks after an implant that could achieve 35Ncm of initial torque would have been able to be loaded.

  27. Just a correction about ITI implants. ITI does, in fact, offer a tapered implant. I’m not sure if it yet has the SLAcitve surface.

  28. Yes ITI has a tapered implant but the taper is near the top, designed to fill an extraction socket. It the goes straight down for about the lower half of the implant. In order to have bone expansion by screwing in a tapered implant, the implant needs to be evenly tapered starting from the bottom and flairing out over most (Screw-Vent)but preferably all (ScrewPlant)of the length of the implant body.

  29. Immediate function and immediate esthetics mean they are only immediate? i.e., no long term function and esthetics? No parameters of selection, no patient needs, only the implant is immediate? And Replace, is to replace every time it does not work? We should bond by phylosophy of treatment, and not by implant brands. Nobel has a wrong phylosophy, and I am sad just to think that Straumann is going the same way with SLActive. All we want is predictability and clear indications for clinical success, despite marketing efforts to push us everything not tested. Stick with SLA and proven ITI phylosophy!

  30. Critical Appraisal of an important citation on the influence of surface on implant osseointegration: (regards to “SLActive” TM)
    Reference: Buser D., Broggini N., Wieland M., et al (2001)
    Enhanced Bone Apposition to a Chemically Modified SLA Titanium Surface.
    J Dent Res;83(7):529-533

    Abstract
    Changes in the surface topography and composition of dental implants are under discussion to have a clinically useable influence on the velocity of early pre-bony tissues. This article discusses this strategy of adapting the surface composition of dental implants to achieve early loading possibilities of dental implants. As a result it can be concluded, that due to the properties and timed sequences of the bony healing, a clinically useful advantage of a modified implant surface under review here, can not be expected.

    Key words
    Implant Surface influence, early loading, bone healing
    Introduction
    Immediate loading has become a hot topic in implant dentistry. It shortens the treatment time and makes it possible to provide the patient with an aesthetic reconstruction even during most of the treatment period. Historically, dental implantologists have followed the well-established Br?mark protocol(1). This protocol requires two surgical procedures separated by a 3- to 6- month healing period(2). Success rates with conventional implant methods are relatively high(3); however, clinically, many patients express the strong desire to receive fixed provisional bridgework immediately after the surgical phase of the treatment.
    Given the desire to produce implants that can be safely administered in immediate loading protocols, manufacturers are eager to achieve this goal by modifying the implant or implant surface that promotes faster healing. Considering the tremendous importance of this endeavor, and the potential for overly optimistic claims, we thought it would be important to look at this topic more critically. Since several studies have been published, including a systematic review(4), on the clinical outcome of immediate loading, our aim was to take a pivotal article used by other researchers and manufacturers to support clinical decision making and claims and to examine its purpose, methods, results and conclusions with a critical eye. The findings from this appraisal may be applied to many studies in dental implantology; therefore, a second purpose is for the reader to consider the strength and limitations of this paper in preparation for future dental implant research.
    Article summary
    The purpose of this study by Buser et al was to examine bone apposition to a modified SLA (modSLA) surface in the maxillae of miniature pigs as compared with a standard SLA surface. The authors hypothesized that the mod SLA surface would promote a faster bone apposition in comparison with the standard SLA surface. This was a prospective matched-cohort animal study using six adult miniature pigs. The test implants were a modSLA surface rinsed under N protection and continuously stored in an isotonic NaCl solution. The control implants had a standard SLA surface. All implants were cylindrical titanium with two circular bone chambers with a depth of 0.75 mm and a height of 1.8 mm (Institut Straumann AG, Waldenburg, Switzerland). Both sets of implants underwent the same sandblasting and acid-etching procedure. Two surgical procedures per pig were performed. In the first surgery, the anterior teeth in the maxilla were removed by means of a flap elevation, careful osteotomy, and tooth separation. After wound closure, the sites were allowed to heal for at least 6 months. In the second surgery, titanium implants were inserted according to a low-trauma surgical technique. The implants were placed, with good primary stability provided by the press-fit of the implants with the bone walls of the prepared implant beds. Three or four implants were inserted on either side of the maxilla, in a split-mouth design. Following irrigation, primary wound closure was achieved with interrupted sutures, and implants were left to heal in a submerged position.
    Four different methods were used for a surface analysis: surface topography, quantitative 3-D topographical analysis, surface wettability, and chemical composition. For the histological preparation and analysis, two miniature pigs were killed after 2, 4, and 8 weeks of healing respectively. In each animal, two bone blocks were removed and immersed in a solution of formaldehyde (4%) combined with CaCl2 (1%). The specimens were dehydrated and embedded in methylmethacrylate. Approximately 500 ?m thickness sections were prepared and stained superficially with toluidine blue followed by basic fuchsin. An assessment of ?bony ingrowth? and ?bone density? was performed. For the histomorphometric analysis, bone to implant contact (BIC; %) was calculated at 2, 4, and 8 weeks.
    The authors reported the following results: No qualitative differences observed in surface topography. No statistically significant differences in surface roughness parameters using quantitative 3-D topographical analysis. Dynamic contact angle (DCA) measurements indicated that SLA was hydrophobic (DCA = 138.3o ? 4.2) and modSLA was hydrophilic (DCA = 0 o; p<0.05). ModSLA had increased oxygen and titanium concentrations (O, 55.0% ? 2.0; Ti, 26.5% ? 0.9) compared with SLA surface (O, 44.2% ? 1.9; Ti, 18.4% ? 1.6). Conversely, modSLA surface demonstrated reduced carbon concentration (C, 18.4% ? 1.6) compared with the standard SLA surface (C, 37.3% ? 3.4). At 2 weeks, bony ingrowth into the bone chambers and direct bone-to-implant contact were evident. A scaffold of ?bone formation? was described. At 4 weeks, bone density increased, as indicated by the reinforcement of woven bone trabeculae. At 8 weeks, bone density in the bone chambers had increased further and early signs of bone remodeling were apparent. At 2 and 4 weeks, significant differences in percentage of BIC between test and control implants were observed. At 8 weeks, no significant differences were observed.
    The authors conclude that the modSLA surface promoted enhanced bone apposition during early stages of bone regeneration. However to their credit, they acknowledge that these findings do not suggest superior bone anchoring at earlier time points.
    What were the study?s methodological strengths?
    The authors used a matched pair design. Comparisons were made within the same pig and within the same region of the mouth. Using the same animal as the control is an excellent method for controlling for factors that may be unequally distributed between implants that are associated with the outcome (i.e., confounding). The authors used quantitative methods (see discussion on appropriateness below) to make comparisons as opposed to purely subjective methods. It is important in animal studies to not just investigate histological findings which are more qualitative in nature but to measure actual changes using histomorphometric or biomechanical methods.
    What were the study?s methodological limitations?
    Despite a matched design, the side of mouth was not randomized. We cannot be sure that all factors that might influence outcome were equal. One cannot prevent bias that may exist by pre-inspecting animals prior to placement of one implant or another. The most critical methodological principle violated was blinding of assessors. If the assessor was not blind (or at least independent) to the implant, we cannot be sure that knowledge of the implant did not have a direct or indirect effect on the interpretation of the analyses.
    Was the preparation of the implant sites relevant to the clinical setting?
    To improve the chances for the successful integration of an implant, a direct bone-to-implant contact must be achieved by the surgeon. This means that there should be no gap between the drilled out cavity of bone and the implant. In this experiment, the authors show large cavities with no direct bone contact. The soft tissue development inside these cavities as well as the later ingrowth of secondary osteons is described. The tissue observed initially is pre-bone converting to woven bone (i.e., a type of endosseous callus which requires a blood clot and space to develop). Space, however, is not present under normal placement conditions in crestal (i.e., screw) implantology.
    The implants used do not appear to have threads in the pictures presented. Clinically, threads influence the load distribution of the implanted bone and interfere with the direction of osteonal repair. If threads are not present, bony ingrowth into the cavities for this experiment are not under ?normal conditions?.
    The authors do not explain their ?low trauma insertion technique?. If no flap was raised during the surgical procedure, this experiment will not be relevant for many dental implant cases. Raising a full thickness flap will create a ?regional acceleratory phenomenon? (RAP) (6), thus reducing the amount of spongious bone between the cortical bone. This reduction of old (mature, mineralized) spongious bone may have a significant influence on the implant stability in the first 4-6 months and may be one of the reasons why crestal implants inserted after raising full thickness flaps in the upper jaw are more safely loaded after 4- 6 months.
    What is the clinical relevance of the chemical composition?

    Increasing the amount of oxygen on the titanium surface of implants is not difficult to do. However, ion exchanges (in-diffusion of oxygen, out-diffusion of titanium) may lead to an overall increase of solubility of the outer area of the titanium body and to a decrease of the integrity thereby increasing the risk of fracture for the whole implant body (5). In particular, with 3.3 mm implants, the fracture resistance is critically reduced, because the thickness of the wall of the implants is thin. The standard implants described in this experiment were designed to be used as additional implants in non load bearing areas. The modified implants (modSLA) are potentially even weaker since ion exchanges of this magnitude do not only affect the actual surface, but create a considerable layer of defect areas in the depth of the surface (5). This may lead to cracks, which ultimately lead to the failure of the Titanium structure as the supporting bone retracts over time from the collar of the implant.
    Fillies et al (8) evaluated SLA-surfaces and showed that the type and roughness of the surface determines the behavior and development of cells with a potential to differentiate. On smooth and microstructured surfaces of pure titanium, bone forming cells are found predominantly whereas the proportion of fibrous tissue cells is lower, whereas fibroblasts (instead of the desired osteoblasts) are increased on SLA-surfaces. This may have a negative influence on the integration of the implants. It may be considered that the changes in surface composition from pure titanium to a titanium alloy (Ti55O18C) caused by the SLA-preparation are one of the major reasons for this observation.
    Were all important assessments performed?
    The degree of mineralization of the newly formed tissues was not determined in this experiment. This however should be a standard procedure for bone quality assessments (7). If this experiment would have shown a considerable amount of mineralization, statements about ?increased bone apposition? would be justified. However, if no mineralization (or an increase in mineralization compared to SLA) was examined, we would have expected a statement about a histologically visible, blood-derived, granulation with later resorption and replacement by osteonal bone. One must be careful when describing this tissue as ?bone?. Standard staining methods, such as tetracycline labeling would have helped to enlighten the histological findings.
    There were no biomechanical tests performed. This makes the inference that stability is increased during the 2 and 4 week period due to increased bone apposition rather tenuous. The authors acknowledge this weakness. Hence claims of this magnitude by manufacturers or other clinicians are not warranted.
    Are there alternative explanations for the findings observed in this study?
    The implants described (modSLA) are supplied in vials containing liquid; therefore, the implants are wet when they are inserted into the bone. Remnants of this wet storage might enhance the liquid quantity available on the surface of the implant after the implant is enveloped into the bone. In order to distinguish between the effects of this NaCl-coating, the modSLA should have been compared to pre-wetted SLA-Implants (using sterile water). One must be careful in assuming the surface made the difference when the wet supply condition may have contributed to an alternate behavior of the tissue. We cannot be sure without a comparable control.
    It seems very unfortunate, that the authors used the term ? increased bone density? instead of e.g ?increase of the volume of non-mineralized tissue?, because the later type of tissue was really observed.
    How might the findings of this animal study be applied to patient care?
    The average implantologist might consider using modSLA implants for immediate or early loading protocols. This should be considered with caution given the findings presented above. There does not appear to be ?bone? available in the vicinity of the implant at this stage of healing; hence, the load bearing capability of the peri-implant bone (being under heavy remodeling) is likely low. Furthermore, without biomechanical testing, a statement of stability cannot be made. However, if prosthetic work pieces are to be inserted at this stage, abutments must be screwed in and tightened (e.g., with 25-30 Ncm) which may impose extremely high forces on the surfaces of bone. Especially in the maxilla, implants may show immediate loosening under these conditions. The bone in the anterior mandible is more resistant and less fragile and may tolerate this approach more successfully. Finally, the authors of this paper acknowledge that these findings do not suggest superior bone anchoring at earlier time points so careful consideration of early loading is highly recommended.

    References
    1. Branemark PI, Hansson BO, Adell R, Breine U, Lindstrom J, Hallen O, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl 1977;16:1-132.
    2. Adell R, Lekholm U, Rockler B, Branemark PI. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg 1981;10(6):387-416.
    3. Gapski R, Wang HL, Mascarenhas P, Lang NP. Critical review of immediate implant loading. Clin Oral Implants Res 2003;14(5):515-27.
    4. Esposito M, Worthington HV, Thomsen P, Coulthard P. Interventions for replacing missing teeth: different times for loading dental implants. Cochrane Database Syst Rev 2004;3.
    5. C. Leyens: Oxidationsverhalten und Oxidationsschutz von Titanlegierungen; In: Peter M. and Leyens C. Titan und Titanlegierungen, Wiley-VCH Publishers, 2002, p. 197-245 ; ISBN 3-527-30539-4
    6. Yaffe A., Fine N., Binderman I. Regional accelerated phenomenon in the mandible following mucoperiostal flap surgery. J. Periodontol, 1994; 65(1): 79-83
    7. Currey JD (1981) In Covin SC (ed): Mechanical properties of bone; Am Soc. Of Mech,Engineers; New York, pp 13-26
    8. Fillies at al.: Prim? Osteoblastenreaktionen auf SLA-und mikrostrukturierten Implantatoberfl?en; Mund Kiefer GesichtsChir, 2005; 9:24-28.

  31. According to the all Dr. Nianick and implant must be tapered from top to bottom. Others see if differently and the conversation about bone expansion is at the heart of this distiction. by having a cylindrical base and a tapered top you can acheive primary stability while filling a socket and not worrying about downward pressure on the bone that would case necorsis. The Straumann TE implant is available with the new SLActive surface. Just as my laptop can do more things faster today than the one I had in 1995 I hope to look at implant dentistry the same way. I don’t want to get stuck doing something because it works when their might be a better way for my patients. It is good to know that SBM stands up well to other surfaces that I don’t use anymore.

  32. In your opinion Dr. Niznick, which is motivated by what you sell. Their are plenty of cases where a continous tapered implant has casued necrosis of the bone by creating a downward force. You may have supplied a drill set that reduced this concern with design but not all other companies did. In fact some delivered new instuments 18 months after they launced the implant and only appeared to change their protocol when implants started failing.

    As for the Straumann TE implant it is available in SLActive. It does taper at the top and is not intended to compress bone at the coronal aspect of the implant. Instead it allows native bone to jump to the surface while providing primary stability at its base. Some surgeons like tapered implants some don’t but to pretend that you must have a design flairing over most or all of the implant body is like listening to a child lie about a broken glass. Either design can work but maybe the Straumann design is less technique sensitive in regards to necrosis when you consider the number of failures with full body tapered implants that eventually caused their manufacturer to change their instrumentation.

  33. The Straumann TE implant is available in SLActive. And unlike implants tapered over the entire body of the implant the Straumann TE has not had problems with causing downward necrosis of the bone. Dr. Niznicks opinion about the flair design of an implant is in fact only his opinion. Some people like tapered implants others feel they get better stability from a cylindrical implant and don’t like tapered implants. I am sure that someone can qoute a study comparing Tapered vs. Cylindrical implants but that study will not compare a fully tapered body vs. a hybrid body like the TE. So it comes back to opinion and surgical experience.

  34. I haven’t visited here much before, and certainly haven’t bothered responding to posts, but the comments by Dr. Niznik on this thread are just hilarious. I am moved to respond

    NiTznik comment

    If an implant can be placed in functional loading immediately, what would be so surprising that it can also successfully be loaded at 21 days?

    What a fatuous comment; it’s the implant that could NOT be loaded immediately, that would not normally be loaded for 6, 8, 12, or however many weeks depending on the implant size, surface, position, on the patients fitness, bone quality etc. Early loading works on splinted implants in the mandible. Proof available in high quality systematic reviews. Not available for any other situation. Data from studies on single teeth are so heterogeneous that no meaningful conclusion can really be drawn other than if the bone ‘quality’ is good enough, some (generally very experienced) people get it to work.

    But if bone quality means insertion torque of the implant, this also means bone compression. (Newton, 1666. Third law, “For every action, there is an equal and opposite reaction.”) Bone compression results in plastic deformation and intense bone remodeling. Threads on the implant may increase the primary stability in the first instance, but cause the compression that results in disruption of the direction of repair of the osteonal structure. Tapered implants achieve primary stability by doing this even more aggressively. This is why the drill systems for many tapered implants were later redesigned when the failure rate was initially seen to be very high.

    Thus the greater the insertion torque, the more compression and the more bone remodeling that occurs. This is why primary stability decreases over the first few weeks and when implants fail, they generally fail early. So, if we can speed up the apposition of new bone on the implant surface and replace the ‘dying’ bone more quickly, we reduce the risk for implant loss.

    Compressing / expanding bone does not improve its? quality. It reduces its’ viability. The only way to ‘expand’ bone is by DO. Anything else is just squishing it.

    By the way, there is not a lesser force inserting an implant into soft bone or greater

    NiTznik comment
    I would like to say that as a prosthodontist it is my hope (and personal opinion) that improved implants like I will be selling will cure systemic disorders such as diabetes for instance… or even cure smokers… well at least stop them from smoking!!!!

    Are you being sarcastic here, or just plain ignorant?

    NiTznik comment
    With 98% success on immediate load with SLA by Wilson… you obviously do not need secondary stability if you have primary (day one) stability.

    This just shows either a lack of understanding of, or contempt for, the basics of bone biology. Come on Dr. NiTznick, can you really tell in every patient whether you have inserted the implant too tight (with consequent peri-implant necrosis); or whether the degree of bone remodeling will not result in micromovement beyond a critical threshold? Every implant needs secondary stability. It’s called osseointegration.

    NiTznik comment
    None of these implants have any waiting period if the quality of the bone is good enough to immediate load the implant. Merely because somewhere in these companies’ marketing literature history, they gave a recommendation for a specific healing time, does not mean that that is when osseointegration will take place.

    Absolutely right. So if you are absolutely sure of the aforementioned processes, absolutely all the time, you can be absolutely sure of a 100% success rate. But the average success rate for all implants placed across the systems that do publish data is 95%. Clearly we are not absolutely sure, and I for one am right behind any researcher that is looking to improve on this, because I could be an implant patient myself one day!

    NiTznik comment
    To tempt the implant Gods by loading an implant in 3-4 weeks in soft bone because a study in some rabbit tibia showed a 20% higher torque removal or 60% of bone contact at 3 weeks vs. 4 weeks, is unwise.

    We rely on science, not religion, in implantology. You may sacrifice patients? implants to the ‘implant Gods’, but most of us try not to. There are several studies now supporting the data on SLActive, and Osseospeed. I support the researchers in their efforts. It’s not so much to make our lives easier, but our work more reliable so that our patients lives are easier.

    Oh, and you need to take the ‘p’ out of your ‘oppinion’ It’s spelt ‘opinion’.

  35. Good discussions. I would offer that if you have not looked at 3i’s new Nanotite implant, you should. It is FDA Approved for immediate loading. They have pre-clinical and clinical data and there has been human histology published. Several collegues report excellent initial impressions and results. I’ve just started to place some and will let you know.

  36. IN REPLY TO :
    “I’ve just started to place some and will let you know.”

    Wow! Here we go again! Let’s try this experiment on our patients and finance it with our inherent time and liability!

  37. All I have to say to all of this is look at who is funding these so called successful research trials.

    If you read the true literature that is not funded by the companies in some way shape or form then you will find that the SLA surface does integrate quicker, however it still is not stable enough in the bone to put any load on the implant.

    They might start ahead in the race, however all implant companies finish at the same time when it comes to time to load an implant.

    As clinicians, we need to be more aware of the studies that are done and who is performing and funding them. This is where the pharma industry is having a ton of problems…Money Talks…and the sad things is most of us are too lazy to uncover the facts instead we listen to marketing!

    As for the TiUnite in Nobel…read Bone Growth 101 and you will find that dental tubules are 1-3 microns in size and an osteoblast is 60-70 micons….I may not be the sharpest tool in the shed however I think those numbers don’t work well with each other…good marketing idea however not a scientifically strong idea…know your science….research the science….and seperate the marketing…you will find the true answer…

    Good luck to everyone

  38. I think we shoul’dn’t mix up the initial stability with the possibility to load in an aerly state and the real osseintergration. I think most of us don’t put real load on the implant in immediate loading. When we drill our osteotomy with bursthen we get a smearlayer, which has to be removed by th body before we get bonecells to grow on the surface of the bone and the implant. I think this situation can only be accelerated by removing this smearlayer by using an er-yag laser for instant or maybe chemical. Maybe straumann put something on its implants to solve the semarlayer and do some acceleration in boneingrow. Any case they have said? Well I refer a patiënt with some degree of osteoporosis ( no fosamax user or somehing like that) and after 8 weeks of healing I could srew one of the implant out of the bone by using handinstruments trying to remove the cofferscrew!!!! This implant was in teh intra-foraminal region!!! So I think not so active as they have presented their implants! SLA Active = serious lower anchorage active ( just kidding). It is good they try to come up with a better product, but I hope not on our costs!

  39. I haven’t found any compelling evidence yet how a surface significantly alters bone repair physiology. The same phases of bone healing around an implant are the same as healing of fractures.

    Phase I of bone healing, the inflammatory phase, lasts normally a few days to a couple of weeks depending on the environment of the osteotomy or socket and what has or hasn’t been added to the wound.

    The repairative phase, phase II, there is a proliferation of osteoblasts (endosteal and periosteal) and they begin to lay down osteoid and chondroblasts form intermediate cartilage (this response is stimulated by local and by humoral mediators). The islands of cartilage and osteoid within granulation tissue slowy merge to form a fibrocartilaginous callus. This process usually takes 3-6 weeks. The callus with slowly calcifies, and begins to stiffen. If there is mobility at this point, a non-union or fibrous union is likely to form. Slowly the callus is replaced with woven or immature bone. This bone is not capable of withstanding load. Primary stability of an implant to this point is purely from the initial retention of the self tapping and pilot drill method (hole smaller than the implant) and the quality of bone at the time of the implant.

    The next phase, the remodeling phase (phase III), the immature, woven, primary bone is replaced by compact/lamellar or mature bone (secondary bone). This phase the primary cell involved is the osteoclasts. If you use radiofrequency analysis at the placement of an implant and get a baseline implant stability quotient (For instance with the Osstel Mentor), you’ll see this effect in the early stage of phase III as the stability quotient falls. Therefore, the implant is less stable here than in was primarily. If an implant is loaded here, as long as the decrease in stability is adequate to withstand the force of the load, the implant will survive, if it is less, it is likely to fail. This process of remodeling, phase III healing, takes 20-25 weeks !! The osteoclastic activity to absorb immature bone and then osteoblastic activity to lay down fresh osteoid in an organized fashion is absolutely necessary to bone strength. There are plenty of evidence based studies (a plethora of studies in the orthopedic literature) that show that the pre-operative strength of the bone is not achieved until the 20-24 week !. Remodeling at the site continues slowly over the next 4-6 months and under load is constantly going through turnover for life. As the implant site is exposed to an axial loading force, bone is generally laid down where it is needed and resorbed from where it is not needed. Adequate strength is typically achieved in 4 to 6 months and therefore it makes sense to load the implant at this period–(described in Wolff’s Law).I have found no compelling randomized controlled blinded studies to believe ANY surface can alter the physiological process.

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