Citation: ELA Svoboda. Dental Implant Prosthesis Installation: 51 Key Questions and Answers to Make Implant Treatment Safer. March 13, 2017. www.ReverseMargin.com

Search Words: dental implants, prosthesis installation, crown and bridge, reduce complications, implant-abutment misfit, residual subgingival cement, safer intra-oral cementation, retrievable prosthetics

 

Abstract:

Dental technology is advancing rapidly and it is allowing us clinicians to exert better control of our treatment outcomes. Yesterday, many clinicians needed to make a choice between two implant prosthesis installation techniques; fully aware that each technique had an inherent problem. Fully aware that screwed-in prosthetics caused a technique related misfit at the implant-abutment junction, and that cement-in prosthetics could cause the residual subgingival cement. Both problems are well documented in the literature. What makes it difficult to choose between the two installation techniques is that the rates of peri-implant disease caused by these problems appear to be similar. Their contribution to peri-implant disease appears to be a whopping 60%!

My research has led me to the discovery of a new truth. Today we no longer need to choose between the two problems, we can prevent them both by a modification to our abutment-prosthesis designs and prosthesis installation technique. This is a real breakthrough that can cause a large drop in the technique related treatment complications!

The key information I have gleaned from my research is; 1. Dental models are inaccurate and are the root cause of the implant-abutment misfit, 2. Safer intra-oral cementation is the key to safer treatment, for both retrievable and non-retrievable prosthetics, 3. Among a growing list of design features and technique modifications, mitigating the Gingival Effects is key to safer intra-oral cementation. The growing list of design features and technique modifications is part of an evolving cement control system. I invite you all to contribute to this evolving system.

My line of research continues to shed new light on several other refinements that promise to make intra-oral cementation even safer. It is also exciting that my work is relevant for prosthetics cemented onto natural teeth.

Of course, without your support, the specialists and future specialists of dental implantology, the implementation of my findings will be much slower. Why should we continue to install our prosthetics in such a way that knowingly creates an implant-abutment misfit or residual subgingival cement? Treatment complications can be very expensive for all us clinicians and the patients we serve.

Dr. Svoboda’s  answers to his proposed 51 Questions are supported by his experience placing and restoring thousands of dental implants, and original research on the subject of safer prosthesis installation. The literature based evidence for his thoughts are referenced in his March 13, 2017 rendition of his presentation, to be delivered at the AAID Conference in Chicago June 2017 and his published articles. The presentation is available for viewing and the articles are all available for free download from this website (www.ReverseMargin.com).

 

  1. Have you ever wondered why dentists need to adjust crowns and bridges during installation? Why do they fit on the model and not in the mouth?
    The fact is that dental models are inaccurate representations of the mouth. This is true whether they are derived from physical or digital models.
  1. What makes the consequence of this model inaccuracy worse?
    The longer the span of the bridge, the greater the number of connected retainers and the greater the length of the implant abutment complex, the greater the impact of model inaccuracy.  This inaccuracy can be particularly damaging when prosthetics are installed by the screw-in technique.
  1. How does model inaccuracy cause problems for implant prosthetics installed by the screw-in technique?
    When the abutment-prosthesis complex is joined together or built together to fit on an inaccurate model, the abutment-prosthesis complex is also inaccurate. When it is transferred to the mouth, the connection between the implants in the mouth and the abutments cannot align properly. Screwing these misaligned components together can put the implant-abutment connection under strain, because they cannot fit together properly. This causes an implant-abutment misfit and resulting consequences.
  1. Are there other things that can contribute to or cause an implant-abutment misfit?
    Yes, tight contacts with adjacent teeth can also prevent the abutment(s) from seating into their retaining implant(s) properly.  It can be very difficult to ensure that the contact does not impede the seating of the prosthesis or the abutment. If the dentist can create a verifiable space between the contact of the prosthesis and adjacent teeth, then it will not affect the seating of the prosthesis and the fit of the implant-abutment junction.
  1. My contacts are perfect; how can you say that they may be causing an implant-abutment misfit?
    It can be very difficult to verify that contacts with adjacent teeth are not interfering with the optimal fit of the implant-abutment connection. Loose abutment screws or persistent inflammation adjacent to the implant-abutment junction may be an indication that the implant-abutment fit may not have been optimal.
  1. Is an implant-abutment misfit dangerous?
    There is some research that proposes that an implant-abutment misfit at the bone level is not dangerous. However, there is abundant research that discusses both the mechanical and biological problems associated with an implant-abutment misfit. Misfits at the implant-abutment junction are dangerous.
  1. What is better mechanically? A joint with an optimized fit or one that is in a misfit situation?
    The answer is clear. The joint with an optimized fit with be better chance at withstanding the loads of function. Indeed, the implant-abutment connection with an optimized fit will have a screw that has not been damaged by the insertion process and a joint that will not be damaged by a misaligned connection.
  1. What do you mean by screw damage during the installation process?
    When a straight screw is used to pull the abutment into/onto the implant, an offset alignment of the implant and abutment will cause the screw to bend under the screw head while turning during insertion. This bending can weaken the screw shaft and cause the head of the screw to break prematurely. This is much like bending a wire coat-hanger back and forth to break it.
  1. What do you mean by damage to the implant-abutment connection?
    When the implant and abutment are offset, the abutment will begin to touch the implant at a point, before something bends or gives, to allow the abutment to seat. The force exerted by the abutment screw is large. If the implant or abutment is too soft, one or both surfaces may become stressed and/or distorted.
    The abutment screw may become loose in response to stress build up in the implant-abutment connection. If that happens, functional loading may also cause a distortion of the implant and/or abutment connections. This potential distortion of the implant connector would not be good for the prognosis of the treatment or even for future retreatment. How could that problem be fixed?
  1. Who is responsible for the technique related implant-abutment misfit?
    Unfortunately, the dentist is responsible for this misfit, because it was caused by the installation technique they chose to use.
  1. How do you correct an implant-abutment misfit?
    Unfortunately, it is often difficult to detect an implant-abutment misfit and it can very difficult to correct. It is better to prevent this serious problem with a safer installation protocol.
  1. What are the implications of not being able to fix the misfit?
    I would guess, the misfit is probably the major reason why attempts to treat peri-implantitis in screw-in cases fails. The clinician can clean up and re-graft a failing site, but if the cause of the peri-implant disease has not been corrected, why would anyone expect success?
    In Wilson’s (2008) cemented cases, 74% of the peri-implant disease cases got better when residual excess cement was removed. The cause was clear and the treatment had a good success.  When the cause of the problem is removed, the disease usually resolves. This is a better case scenario.
  1. What about the Implant-abutment manufacturers, are they responsible for the problem as well?
    They are to responsible making components that fit properly and that can withstand the forces of occlusion/function. Precision costs money. Dentists should choose products from manufacturers that can provide mechanical precision and stability, and educate their patients of the value of that mechanical stability. The implant industry might do well to educate itself about this problem, and perhaps help fund education that informs their customer base about this problem. This is especially true now that a good solution to this problem has been found. Treatment complications are expensive for all and may drive down demand for implant services and products.
  1. Can we exclude pathogens and their endotoxins from the implant-abutment connection?
    The implant industry still has more work to do in this area. However, dentists must first learn to optimize the implant-abutment connection by their prosthesis installation techniques. What good is spending a lot of money to make precise connections when the installation technique does not take advantage of that important and expensive attribute?
  1. How can we optimize the implant-abutment connection?
    The answer is quite simple. Dentists should understand that dental models on which prosthetics are constructed are inaccurate. Some tolerance needs to be built into the prevailing installation technique, to compensate for this model inaccuracy. Dentists can already compensate for this model inaccuracy by intra-oral cementation. It is the cement space that builds tolerance into the system. However the factors affecting the flow of cement are poorly understood and prevailing cementations methods can be risky. New information discovered by the author can make intra-oral cementation safer.
  1. How does intra-oral cementation help us optimize the implant-abutment connection?
    The most important part of this answer is that the abutments are installed onto their retaining implants individually. This allows the dentist to optimize the implant-abutment fit prior to attaching the prosthesis. This contrasts with the screw-in technique, where the abutment-prosthesis complex is fixed into a rigid inaccurate complex before installation.
  1. The cemented prosthesis was built on an inaccurate model. Isn’t it inaccurate?
    Yes of course, the prosthesis is still inaccurate. However, the abutments will already have been installed before the prosthesis, and the implant-abutment connections will already be optimized. Then it is the cement space that can be used to compensate for prosthesis inaccuracy. Before prosthesis cementation and it is much easier to adjust its fit, adjust its contacts and adjust its occlusion, because it can easily be taken in and out. At the time of cementation, it will be easier for the clinician to control the process and create a passive fit with the retainers.
  1. How much cement space should we leave to ensure a passive fit between the abutment(s) and the prosthesis?
    I like to use 80 microns and I like to use an acrylic based cement. The 80 microns cement space seems to be enough to compensate for model error. If the prosthesis binds against the contacts or the retainers, it is relatively simple to remove the prosthesis from the mouth and adjust it to fit prior to cementation.
  1. Why do others like a smaller cement space? Some even like a tight fit against the retainer(s).
    The smaller cement spaces and the tight fits have evolved from a time when cements lacked compressive strength and they tended to dissolve away at the margins.
    Acrylic based cements have high compressive strength, low solubility and high retention. They are also easy to use, have an even consistency and have plenty of working time. In the putty stage, they are easy to clean away and do not become weaker with a cement space in the order of 100 microns and even more.
  1. Why do many clinicians avoid methyl methacrylate based cements?
    There are many reasons. Some dentists like to use temporary cement in order to make the prostheses retrievable for service. It can be very difficult to separate a prosthesis from its retainer(s) once cemented with a resin cement. If you would not like the prosthesis to be removable from the abutments, then resins cement are an excellent choice.
    There is some research that indicates that bacteria grown on resin cements is more abundant than on other cements like Zinc Phosphate. This can be a confusing observation. We already know that zinc phosphate lacks compressive strength and washes out at the margins. We also know that we need to put a varnish or some other protective liner between zinc phosphate cement and the pulp because it can have a negative effect on the pulp.
    Is the ability of methyl methacrylate based cements to grow bacteria a sign of biocompatibility, like cementum, enamel, titanium and zirconia? Is the inability to grow bacteria a sign of biological toxicity, like zinc phosphate? It is best to keep any cement out of the deep tissue spaces whenever possible.
  1. Is methyl methacrylate based cement used anywhere else in the body?
    Yes, it is used in great quantities by the orthopedic surgeons to hold in large titanium knee replacements and hip joints.  They also have failures over time.
  1. Some dentists just feel safer using Zinc Phosphate to cement their prosthetics. Is that good?
    I am not sure what is the best. I feel that the methyl methacylate question is unresolved and that it is probably best to use it and other cements in a equigingival environment whenever possible. According to the work or T Wilson (2008), he found that any of the 4 types of cement, including Zinc phosphate could cause peri-implant disease when left in the subgingival environment. Wherever you will use Zinc Phosphate it will lack compressive strength and will wash out at the margins. This cement wash-out is probably responsible for the top 3 reasons natural tooth retainers fail after 10 or so years in the mouth. Is it good to have cements wash out at the margins and create voids under the prosthesis? Probably not.
  1. What cement do you like to use, at the present time?
    At the present time, I like to use an acrylic based cement and ensure it does not go into the deep subgingival environment.
  1. Is residual subgingival cement not a problem related to intra-oral cementation?
    Yes, residual subgingival cement is a big problem. The dynamics of cement flow during the process of intra-oral cementation are poorly understood. Thus, some clinicians have tried to avoid this treatment modality in favor of prosthesis installation by the screw-in technique. Unfortunately, despite their frustration, they still cement prosthetics onto natural teeth. I feel they are putting too much faith in the ability of a healthy gingiva and a healthy periodontal ligament to prevent damaging cement flow. How many healthy teeth are we cementing crowns and bridges onto? Is a 3 or 4 mm periodontal pocket a sign of health? Do you think residual cement 3 or 4 mm below the gingiva is OK? We must prevent the occurrence of any residual subgingival cement.
  1. How do you prevent the occurrence of residual subgingival cement?
    Nobody has ever published information about the effect of gingiva on the flow of cement as it leaves the margins of the prosthesis during the process of intra-oral cementation.  New information about the “Gingival Effects” has resulted in a safer cementation process that can prevent residual subgingival cement.First, whenever possible, keep margins in the supra-gingival or equigingival environment (Wadhwani 2016). This requires the use of a site specific custom abutments.Second, whenever the clinician chooses to place the margins into the subgingival environment, they should use an inflected margin, called the Reverse Margin design, to redirect excess cement away from the tissues.  Current margin designs, like the feather and the chamfer margin, direct cement into the tissue spaces.
  1. Is margin location and margin design enough to control cement?
    In the supra-gingival environment, it is probably OK to use any margin design. When the prosthesis margins are placed into the subgingival environment, even a great margin design, like the Reverse Margin is not enough. Beware of the Gingival Effects!
  1. Why not?
    When margins are placed into the subgingival environment the effect of gingiva, as it interacts with the prosthesis, can have a major effect on cement flow, regardless of margin design.
  1. I never heard of this before. Are you sure?
    Yes, my research has led me to learn about and describe how adjacent gingiva can have a huge effect on cement flow, as it exits the margins of the prosthesis. To my knowledge, no one has ever published on this subject.
  1. What did you discover about the Gingival Effects?
    During the process of intra-oral cementation, as the clinician pushes the prosthesis into place, the convex shape of the prosthesis may touch and form a seal with the gingiva prior to the margins being seated into place. This gingiva-prosthesis seal prevents excess cement from leaving the tissue space while the prosthesis is still being pushed into place. Thus, the cement already trapped in the tissue space, plus the excess cement still leaving the prosthesis is put under pressure by the downward movement of the prosthesis. As the cement is put under pressure it will follow the path of least resistance and can go deep into the tissues, where it is difficult to locate and clean away. This can cause deep residual subgingival cement.
  1. What makes this problem worse?
    The skinnier the implant, the deeper the margin, and the more we depend on the prosthesis to create the emergence profile, the more likely we will end up with residual subgingival cement.
  1. What about use of stock abutments for cemented crowns?
    Stock abutments are often skinnier that the prosthetic teeth they will retain, have a fixed margin location and depend upon the prosthesis for creating the emergence profile. They are likely to cause residual subgingival cement.
  1. What about use of custom abutments that have been cast onto a milled UCLA type base?
    These types of custom abutments can be made to control cement flow, like the “well designed” milled custom abutments described by the author in his publications. However, the process of casting and removal of investment material can damage and distort the base of the abutment that connects to the implant. Thus, this process can create a poorly fitting connection with the implant at the deep bone level. This process is not recommended to produce custom abutments.
  1. Is there a way to prevent this problem? Can we mitigate the Gingival Effects?
    Yes. Once the Gingival Effects were understood it was possible to change the design of the abutment and prosthesis to mitigate the resulting problems related to cement control. The good news is, that most of the design changes could be made in the dental laboratory and these changes often can make the installation process much easier for the dentist.
  1. What is the nature of these changes?
    The abutments need to be customized to control the margin height and margin design. The design changes would bring the margin height above the gingiva whenever possible, and create a relative barrier to cement penetration at the abutment-gingival connection.Whenever it was desirable to bring the margin into the subgingival environment, the abutment shape would again be altered to push against the gingiva to create a relative barrier against cement flow, the margin would be inflected (Reverse Margin design) to redirect the cement out of the tissue space. In addition, the abutment-prosthesis shape would be altered to allow the free flow of excess cement out of the tissue space and thus mitigate the Gingival Effects.A small lateral bumper, 0.15 mm, on the margin rim of the abutment could help push the gingiva away from the prosthesis undersurface and give the dentist a tactile base against which to instrument and remove the excess cement lying on that base. These design alterations facilitate cement control and its effective removal.
  1. How do these design changes make installation easier for the dentist?
    Once the “well designed abutment” is screwed into place, the prosthesis will fit onto the abutment without resistance from the gingiva or the abutment. It is then easy to check and adjust contacts and occlusion. Once the fit is confirmed, the prosthesis can be loaded with cement and pushed into place over the abutment(s). This can be done with super low installation pressures because there are not tight contacts to overcome and no gingiva to compress. This is now a much better controlled, low stress process for the dentist. When the excess cement is in its doughy state, it is easy to instrument away.
  1. Is this process limited to certain abutment or prosthesis materials or cement types?
    No. The hydrodynamics of the cement flow is essentially similar. However, when using different cements with low compressive strength and poor solubility characteristics, they will probably cause problems related to those less desirable characteristics. Their properties may also further deteriorate when wishing to use larger cement spaces to aid cement flow and compensate for model error.
    Perhaps, retrievability is best achieved by including retrievability features into the treatment plan, rather than using temporary cements.  It may be a myth that temporary and other cements are more desirable than acrylic based cements in the subgingival environment. Perhaps swallowed or detached crowns at inconvenient times are a bigger risk than cutting off and replacing the odd prosthesis.
  1. What are retrievability features?
    Retrievability features are characteristics of the treatment plan that allow the clinician to remove and replace a prosthesis without any critical damage.
  1. Are these retrievability features related to the screw-in prosthesis installation technique?
    Not exclusively. To screw-in an abutment-prosthesis complex, the implants and adjacent teeth must allow for a working path of insertion. This is the most important retrievability feature. This feature can also be built into a treatment involving a cement-in prosthesis. That would make the cement-in prosthesis retrievable as well. Both screw-in and cement-in prosthetics can be made retrievable if appropriate retrievability features are in place.
  1. How can a cement-in prosthesis be made retrievable?
    When a screw-in prosthesis is considered retrievable, the abutment screws can be accessed through a hole in the prosthesis, the abutment screws can be loosened and whole abutment-prosthesis complex can be removed from the mouth. With retrievability features built into the system, the same would apply to a cement-in prosthesis. The abutments screws could also be accessed through a hole in the prosthesis and the whole abutment-prosthesis complex could also be removed from the mouth.
  1. Is it necessary to remove a prosthesis to tighten or change an abutment screw?
    No. It is only necessary to access the abutment screw.
  1. What are some other retrievability features?
    Multi-unit abutments were developed by the implant industry to build a little tolerance into the multi-unit prosthesis, to aid in its installation. Because of model inaccuracy and the non-absolutely-parallel nature of integrated dental implants, the implant industry needed to create a sloppier fit for abutments to prevent them from binding during prosthesis insertion. This sloppier fit can more easily fool the dentist into thinking their fit is good.The angled screw channel screw is another innovative invention. It is useful to help move the position of the screw-access channel into a more desirable location on the occlusal surface of the prosthesis. However, like the multi-unit abutment, it does not solve the problem of the implant-abutment misfit.
  1. Can the problem of the implant-abutment misfit created by the screw-in technique be solved?
    Yes, this is described by the Svoboda Modification to prosthesis installation. Once the desired retrievability features are built into the treatment, the abutments can be installed into the mouth individually to optimize their fit.  Then the prosthesis can be cemented onto the abutments. Depending upon the desired version of the Svoboda Modification, the abutment-prosthesis complex can be removed and re-installed at will. However, the implant-abutment connections will have been optimized.
  1. Is there a cost to adding retrievability features into treatment?
    Yes, there can be a large cost to adding retrievability features to a treatment. Like any treatment plan, this cost should be considered prior to treatment.  Adding retrievability features can result in extra site development procedures to allow for parallel implants,  add extra imaging and surgical guide costs, can add to extra laboratory costs for parts and labor and can add risk to treatment due to the implant-abutment misfit, loose screws, fractured porcelain, access hole maintenance and failure of site development procedures. Adding retrievability features to treatment may be far from free.
  1. You have published an article on preventing cement voids. Is that really a problem?
    Have you ever removed a temporary crown and seen a black residue, smelled a terrible smell, or had your patient tell you that they had a foul taste in their mouth? Do any of you remember that foul smell when you took those imprecise abutments off those early implants? Microbes enter voids and can create many problems, including mucositis and peri-implantitis. With prosthetics on natural teeth, cement washout at the margins is responsible for caries, pulpal disease and structural failure. This is also responsible for gingivitis and periodontitis. Is that important? Are voids good? There is abundant literature about the problems of voids both at the implant-abutment junction and under the prosthesis.
  1. Can cement voids be prevented?
    Yes, cement voids can be prevented by overfilling filling the prosthesis with cement, in such a way as to prevent air entrapment and ensuring that excess cement is extruded from the entire periphery of the prosthesis during intra-oral cementation. The margins should be kept supragingival whenever possible and when the margins go into the subgingival environment, the Cement Control System concepts should be used to prevent residual subgingival cement. At this time, I prefer to use a cement that has a high compressive strength, does not wash out, like an acrylic based cement.
  1. What about voids at the implant-abutment junction?
    Yes, these voids are a great concern to me and the whole implant industry. At least the dentist should understand how to optimize the implant-abutment connection and not make that connection worse by their installation procedure. Many fine researchers have published about the implant-abutment misfit problem and I cannot understand why some speakers choose bias their lectures by ignoring this research.
    Once the dentist optimizes the implant-abutment connection, then they will find great value in using parts from manufactures that are more mechanically stable and can prevent bacterial ingress better. Connection design is important and precision costs money. This money is well spent when it can reduce treatment complications.  Treatment complications can be very expensive for the dentists and the patients they serve.
  1. What about the “implant replica technique” for reducing residual subgingival cement?
    The purpose of intra-oral cementation is to retain the prosthesis and to fill all the space between the prosthesis and the retainer. The second part prevents bacteria from entering the space between the prosthesis and retainer.The implant replica technique cannot control the advent of residual subgingival cement, but can make it more difficult to find and clean it away. The bigger problem is, it is more likely to cause cement voids due to lack of cement volume and air entrapment. It is a flawed system. More details are available in my article on the subject. How do you detect and correct a cement void? Persistent pathology may be a clue, but you will need to remove and perhaps replace the prosthesis prior to re-installing it as described in the Cement Control System. This system is designed to prevent a cement void re-occurrence.
  2. How did you calculate the 60% reduction is peri-implant disease by preventing the advent of residual subgingival cement?
    I assumed that, all other things being equal, the difference between the cement-in technique and the screw-in technique relates to the advent of residual subgingival cement for the former and the advent of the implant-abutment misfit for the later.  These complications are unique and inherent to each installation process. Indeed I also assumed that the cemented prostheses all had optimized implant-abutment connections and all screwed-in prosthetics had no residual subgingival cement.In Wilsons study (2008) he studied only single cemented crowns. He found that he could find residual subgingival cement in 81% of the cases with peri-implant disease and 74% of them got better when the excess cement was removed. If one multiplies 81% by 74% then it gives 60%. This is the reduction in disease I would expect if the residual subgingival cement was prevented from going into in the subgingival environment in the first place.If I could get a 60% reduction in complications by optimizing the implant-abutment junction and preventing residual subgingival cement with the cement-in technique, then if I can optimize the implant-abutment junction for the screw-in technique, well I expect the same reduction. The logic is good and the reduction would be amazing.So far, I have not read anything that would be inconsistent with my calculations. Time will tell whether the figures are correct.
  3. Can the Cement Control System concepts be applied to prosthetics cemented onto natural teeth?
    Of course, when dealing with natural teeth, cement flow is still affected by margin height and margin design. When margins are placed into the subgingival environment, excess cement flow is still affected by adjacent gingiva and the Gingival Effects still apply.I am working on this project as well. When I look at the depth of subgingival margins created to restore natural teeth, I suspect that residual subgingival cement is a huge problem. I also suspect that continued use of cements that wash out at the margins, will also continue to contribute to the future failure of the teeth and their attached prosthetics. There is much work to be done to reduce these complications.If the clinicians know that they are going to leave behind cement with current techniques, perhaps a discussion with the patient would be in order before treatment begins. This discussion may deal with the consequences of margin placement and  the possibility of surgery to remove excess cement.
  4. Are there nuances to the application of the Cement Control System to natural teeth?
    Of course, all our treatment in the mouth has nuances.First, always discuss with you patient whether they need to have their margins in the subgingival environment and are willing to accept the consequences of that decision. This will surely reduce that requirement, as it has for me.Second, there are some teeth that are just too narrow to allow for a Reverse Margin design. Perhaps, a Reverse Margin design can be accomplished on the facial, but all the other margins will be supragingival and may be fine with another design. Perhaps the prosthesis can also be made less convex in the subgingival area on the facial aspect, to prevent or reduce the gingival effects on excess cement.Yes, it is good for the clinician to understand the implications of my work so that they can make wise decisions to help protect their patients from the consequence of residual subgingival cement. If the clinician cannot control the cementation process and are not confident that the excess cement has been removed, then it is necessary to use an endoscope like Wilson (2008) or raise a flap and take it away.  If the clinician used too little cement and caused a cement void, well perhaps they will need to cut off the prosthesis and start again.
  1. How do we make our installation systems safer now?
    Dental technology is advancing rapidly and it is allowing us clinicians better control of our treatment outcomes. Yesterday, many clinicians needed to make a choice between two implant prosthesis installation techniques, fully aware that each technique had an inherent problem. Fully aware that screwed-in prosthetics caused a technique related misfit at the implant-abutment junction, and that cement-in prosthetics could cause the residual subgingival cement. Both problems are well documented in the literature. What makes it difficult to choose between the two installation techniques is that the rates of peri-implant disease caused by these problems appear to be similar. Their contribution to peri-implant disease appears to be a whopping 60%!My research has led me to the discovery of a new truth. Today we no longer need to choose between the two problems, we can prevent them both by a modification to our abutment-prosthesis designs and prosthesis installation technique. This is a real breakthrough that can cause a large drop in the technique related treatment complications!

 

The key information I have gleaned from my research is;

  • Dental models are inaccurate and are the root cause of the implant-abutment misfit
  • Safer intra-oral cementation is the key to safer treatment, for both retrievable and non-retrievable prosthetics
  • Among a growing list of design features and technique modifications, mitigating the Gingival Effects is key to safer intra-oral cementation.

The growing list of design features and technique modifications is part of an evolving cement control system. I invite you all to contribute to this evolving system.

My line of research continues to shed new light on several other refinements that might make intra-oral cementation even safer. It is also exciting that my work is relevant for prosthetics cemented onto natural teeth.

Request for Support: Of course, without your support, the dentists, the specialists and future specialists of dental implantology, the implementation of my findings will be much slower. I am committed to this research and hopeful for receiving your support. Why should we continue to install our prosthetics in such a way that knowingly creates implant-abutment misfits and/or residual subgingival cement? Treatment complications can be very expensive for all us clinicians and the patients we serve.

You are my peers and colleagues. I encourage you to take the time to study and evaluate my slide presentations and articles. I would welcome your comments and I would be happy to address your concerns. Let’s work together to make this world a safer place.

If you are a teacher, I invite you to include my work in your discussions and in the formulation of your research projects. I can help support your efforts intellectually and with the parts you see in my videos.

If you are on your way to become an implantologist, I invite you to study my work and let me support your efforts to implement my ideas into your safer treatment protocol.

If you are an experienced clinician and/or a lecturer, I would be happy to supply you with my latest videos and articles, in hope that you will assess the content and help spread the word. I would also be happy to help you integrate my designs into your clinical workflow, so that you and your patients can experience its value.

If you wish to have me speak at your study club or educational institute, I can speak for an evening, or any time up to 2 days about safer installation techniques, and how I use them in my treatments. I am happy to submit a written itinerary to fit your agenda.

Emil LA Svoboda, PhD, DDS, Fellow of the AGD, Honored Fellow of the AAID and Diplomate of the ABOI/ID

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