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- K. F. Chow BDS., FDSRCS April 6th, 2010Many of my complex cases are treatment planned with both narrow diameter and regular diameter dental implants. My experience in cases when I use only narrow diameter is that I complete my cases much faster than when it involves regular diameters. As such, it behoves serious practitioners to keep both types in mind when treatment planning because I forsee that we are beginning to shift towards a more balanced and sensible approach rather than a prejudiced and narrow approach.Cheers!
- Richard Hughes, DDS, FAAID, FAAIP, DABOI April 7th, 2010Dr. Chow: I agree.
- sergio April 7th, 2010Couldn’t agree with you more, Dr.Chow.
Saturday, May 8, 2010
NARROW DIAMETER DENTAL IMPLANTS
NARROW DIAMETER DENTAL IMPLANTS
K. F. Chow BDS., FDSRCS November 13th, 2009
Thanks for the kind words guys. While I am yet feeling elated and therefore a little brash, let me push the debate a little further.
We all know that the transmucosal passage of the dental implant when compared to the transmucosal passage of an actual, real, original living tooth is actually a pathetic imitation of the real thing. The real thing has a nice epithelial attachment with a nice drain around the tooth constantly flushed with antibacterial substances and prohealth nutrients for the gingivae. Not only that the gingival cuff has circular fibres, connective tissue to tooth fibres, bone to tooth fibres , connective tissue to bone fibres etc. that gives each tooth a nice firm resilient yet elastic cuff around the it. Go review your periodontology texts and see for yourself.
The dental implant has only a pseudo epithelial attachment and a few if any specialised soft tissue fibres and at best is actually an iatrogenic and pathetic imitation of the original! The Archilles heel of dental implants is this transmucosal passage. Peri-implantitis is a problem we all have to tackle like periodontitis. And with dental implant placement growing in the double digits around the world, it is going to be an increasing problem.
The best solution is probably a tooth germ implant which may be a generation away. We may be stuck with dental implants for some time yet.
One way to tackle it and hopefully to decrease the incidence of peri-implantitis may be to decrease the diameter of the implants as it emerges through the mucosa. One shortcoming of conventionals is its large diameter especially done in the name of an aesthetic emergent profile. Narrow diameters may be one of the answers to decreasing and managing the incidence of peri-implantitis.
One way to tackle it and hopefully to decrease the incidence of peri-implantitis may be to decrease the diameter of the implants as it emerges through the mucosa. One shortcoming of conventionals is its large diameter especially done in the name of an aesthetic emergent profile. Narrow diameters may be one of the answers to decreasing and managing the incidence of peri-implantitis.
Nuff said.
NARROW DIAMETER DENTAL IMPLANTS
- Ken Clifford, DDS October 24th, 2009Dr Chow - Amen to all your comments. There is absolutely no reason not to use mini implants. I have been cementing full arch mini implant hybrid bridges as a denture alternative for the past two years. My opinion is that a CEMENTED bridge on mini implants is an affordable alternative for patients unwilling or unable to pay for the all on four bridges, or the conventional implant porcelain/metal solutions. Cementation to minis eliminates the micromovement responsible for most implant failure in a full arch situation. By using quality denture teeth and a quality denture acrylic with high flexural strength, I can quickly construct a highly aesthetic denture alternative which can be loaded immediately. Patients go home happy, and so do I!
- Paresh B Patel October 27th, 2009Dr. Chow, thank you for your well organized and eloquently articulated thoughts on the current state of mini implants. I look forward to reviewing your text “Minimized Dental Implants”
NARROW DIAMETER DENTAL IMPLANTS
K. F. Chow BDS., FDSRCS October 23rd, 2009
Narrow diameter dental implants are being increasingly used not only to stabilize dentures but also for long term applications like crowns and bridges. I agree with Carl in that there is no such thing as an absolute contraindication in medicine. Even botox which will kill you if injected into your bloodstream is used ingeniously and judiciously to extend the youthful looks of people. The key word is “judiciously”. Know your medicine well and know what you want to do with it and then you can apply it safely and usefully.
It is significant that one of the doyens of implant dentistry has recognized that narrow diameters have their uses especially in narrow ridges and in suitable bone. I started out with conventionals and with the advent of minis, incorporated them into my treatment planning and in many complex cases have successfully integrated them both into my treatment planning taking into consideration the patient’s expectations and budget,the materials available and their limitations and my own experience, knowledge and skill.
However, with the greatest of respect, having read the classic Contemporary Implant Dentistry, I wish to highlight some misconceptions and give my opinion.
As pointed out earlier, many narrow diameters or minis used for fixed applications are 2.4mm to 2.9mm in diameter and are made of solid titanium alloy grade 5. They are certainly stronger than say a 4mm diameter fixture that has a hole in the middle to receive an abutment. Say the abutment is 2mm in diameter. That leaves the surrounding rim with a thickness of only 1mm! That is weaker definitely than a solid 2.5mm diameter mini. Furthermore, many of the conventional fixtures are made of titanium grade 3 or 4 which is 99.9% pure titanium and is softer and therefore weaker than the alloy.
One piece minis heal very well if they are placed in with a torque of at least 35 to 50ncm.Reason being that the healing challenge is much less than conventionals and also the transmucosal wound is very small, so that chances of infection in a normal patient is minimal.
As for the misconception that the surface area is insufficient, Paresh Patel has given an eloquent correction to that. Minis are usually placed longer than conventionals and in multiples. So as Patel has pointed out, two 2.5 by 10mm minis give a total surface area of 157sq mm. This has a greater surface area than a conventional of 4 by 10mm which gives only 125sq mm. 2.5 by 13mm gives 100sq mm. 2.5 by 16mm gives 125sq mm. All these are commonly used such that the argument of insufficient surface area for osseointegration holds no water.
The initial or primary stability of minis, I find often surpasses that of conventionals. In fact, I surmise that because of the minimal trauma and small entrance, the surrounding bone and soft tissue has overwhelming healing advantage when compared to conventionals that invokes a much greater healing challenge to the surrounding tissues. The overwhelming healing advantage in the context of minis may mean that the classical necrotic margin phase of osseointegration may be bypassed and osseointegration in the case of minis may be taking place almost immediately. Anyone wants to do a PhD on this?
Narrow diameter users must concede however that the charges of inadequate prosthodontic solutions to solve the problems of non-parallellism, insufficient prosthetic components, and poor emergence profile may have some credence. These problems I believe are being sorted out. As it is, narrow diameters or minis are here to stay and will be increasingly integrated into treatment plans to cater to all sorts of situations that it can solve much better than conventionals. I look forward to minis making great strides to make the benefits of implant dentistry affordable to everyone who needs them, and not just to the well-off only. I forsee that they will play an increasingly greater part in the development of implant dentistry and am preparing a book…”Minimized Dental Implants” and hope to outline and deliver elegant prosthodontic solutions to minis that will address the current shortcomings as pointed out.
Friday, May 7, 2010
HOW TO AVOID DOING A SINUS LIFT.
K. F. Chow BDS., FDSRCS May 7th, 2010
Dear Dr A,
I guess you are another fictitious Doc with an alphabet. Nevertheless, it is an interesting question.
If you do not want to do a sinus lift, any reason will do though it might not be a good one. I myself once did not want to do it because I hated having to make a large opening into the sinus! And if I can avoid it, I did. So I tried crestal lifts invented by Summers. Works, but often found myself having to spend more time than if I just did a lateral window which is more sure and definitive. There are various ingenious ways nowadays, the latest seem to be the “hatch” technique with a special off centre drill.
However, if you want to avoid all these, there are several ways to avoid a sinus lift altogether:-
* Do a conventional bridge on adjacent teeth. Use the tooth in front and the tooth behind the edentulous space. Or a cantilever might work.
* Place an implant in the tuberosity where there is usually more than enough bone and join it to the natural tooth just anterior to the edentulous space.
* Or use MINIs! Do a tripod. 3 minis with the tips cut off at 5mm length, and build a crown on it.
* 2 or 3 Minis carefully threaded into the walls of the sinus on the buccal and the palatal where there is usually 3-5mm thickness of bone. These technique requires a lot of skill and experience though.
* Use short large diameter fixtures from Bicon, Endopore or some of these Korean makers that come in diameters up to 8mm!
* Or like Dr Richard Hughes suggest…. place in a subperiosteal.
* Do a conventional bridge on adjacent teeth. Use the tooth in front and the tooth behind the edentulous space. Or a cantilever might work.
* Place an implant in the tuberosity where there is usually more than enough bone and join it to the natural tooth just anterior to the edentulous space.
* Or use MINIs! Do a tripod. 3 minis with the tips cut off at 5mm length, and build a crown on it.
* 2 or 3 Minis carefully threaded into the walls of the sinus on the buccal and the palatal where there is usually 3-5mm thickness of bone. These technique requires a lot of skill and experience though.
* Use short large diameter fixtures from Bicon, Endopore or some of these Korean makers that come in diameters up to 8mm!
* Or like Dr Richard Hughes suggest…. place in a subperiosteal.
Now all of the above require quite a lot of skill and experience…..maybe you might just want to learn to do a lateral window sinus lift which actually, once you get the hang of it may be actually simpler and surer in results!
Cheers.
Sunday, January 3, 2010
Extra Wide Implants for Immediate Placement: Any Experience with These? | OsseoNews Discussions on Dental Implants
Extra Wide Implants for Immediate Placement: Any Experience with These? | OsseoNews Discussions on Dental Implants: "K. F. Chow BDS., FDSRCS November 28th, 2009
I agree with Professor Tarek from that ancient city of knowledge, Alexandria. Its got the largest library in the ancient world. His approach is very sensible because it allows the bone and mucosa to heal and any infection to disappear. A 3.5mm diameter implant is reasonable as it allows plenty of marginal bone around it. I believe that the learned Professor will place implants that are at least 10mm long or more, based on the quality and quantity of the bone available.
The assumption that the fixtures used should at least match the size of the roots of the teeth that it is replacing is fallacious or to say it simply, incorrect.
The natural tooth is attached to the bone via a highly sophisticated biological structure called the periodontal apparatus. The dental implant is attached via osseointegration, a form of ankylosis. This normally pathologic occurence is now being used to attach all our much vaunted titanium screw implants. The surface area for effective ankylosis for the implant is much less than is required by the natural tooth for the periodontal apparatus[as we all know]. Briefly, it means the titanium fixture can be smaller in surface area than the tooth that it is replacing….probably only half is enough!
Folks, it means that we need not copy Branemark’s original assumption, which is reasonable at the time. But now with hindsight and understanding of osseointegation, we can use smaller-than-the-root implants and therefore Professor Tarek is right.
As for the wide diameter implants, I use them too for immediate extraction of molar cases. It gives good primary stability, cuts down on bone graft and gives good emergence profile….and of course faster turnaround for the patient and faster cashflow..sic.
But I am a bit worried about the extra large iatrogenic pocket that will result. The pocket will not only be vertical but horizontal since the surface of the larrrrge diameter implant will not be covered with bone but connective tissue which…err…does not integrate to titanium..what.?.
Got to shut up now before I decide to stop messing around with implants.**@@!"
I agree with Professor Tarek from that ancient city of knowledge, Alexandria. Its got the largest library in the ancient world. His approach is very sensible because it allows the bone and mucosa to heal and any infection to disappear. A 3.5mm diameter implant is reasonable as it allows plenty of marginal bone around it. I believe that the learned Professor will place implants that are at least 10mm long or more, based on the quality and quantity of the bone available.
The assumption that the fixtures used should at least match the size of the roots of the teeth that it is replacing is fallacious or to say it simply, incorrect.
The natural tooth is attached to the bone via a highly sophisticated biological structure called the periodontal apparatus. The dental implant is attached via osseointegration, a form of ankylosis. This normally pathologic occurence is now being used to attach all our much vaunted titanium screw implants. The surface area for effective ankylosis for the implant is much less than is required by the natural tooth for the periodontal apparatus[as we all know]. Briefly, it means the titanium fixture can be smaller in surface area than the tooth that it is replacing….probably only half is enough!
Folks, it means that we need not copy Branemark’s original assumption, which is reasonable at the time. But now with hindsight and understanding of osseointegation, we can use smaller-than-the-root implants and therefore Professor Tarek is right.
As for the wide diameter implants, I use them too for immediate extraction of molar cases. It gives good primary stability, cuts down on bone graft and gives good emergence profile….and of course faster turnaround for the patient and faster cashflow..sic.
But I am a bit worried about the extra large iatrogenic pocket that will result. The pocket will not only be vertical but horizontal since the surface of the larrrrge diameter implant will not be covered with bone but connective tissue which…err…does not integrate to titanium..what.?.
Got to shut up now before I decide to stop messing around with implants.**@@!"
Extra Wide Implants for Immediate Placement: Any Experience with These? | OsseoNews Discussions on Dental Implants
Extra Wide Implants for Immediate Placement: Any Experience with These? | OsseoNews Discussions on Dental Implants: "*
December 15th, 2009
Dear osurg,
“Iatrogenic”, according to Webster’s is defined as, “induced inadvertently by a physician”.
When we insert a dental implant into the bone and gums, we create a pocket around the neck of the implant as it traverses through the gum and into the oral cavity. This pocket is different from the normal gingival sulcus that is found around a normal tooth. When the gingival sulcus become diseased due to infection, trauma or abnormal immune response……it becomes inflamed and deeper and the diseased state is then called a pocket. I call the corresponding sulcus around the dental implant as it emerges into the mouth a pocket because it is not normal but a pathology. In this case the pathology is physician-induced and therefore iatrogenic!
If we examine the pocket around the implant histologically, it is a vast difference from that of a normal gingival sulcus. There are no true fibrous attachment like on a real tooth, only a pseudo-attachment and connective tissue that contains a higher number of defense cells than normal.
Yea, everytime we place a dental implant, we create a pocket….. a pathology…yep…..a diseased state. It is a fact that we must recognise so that we will use dental implants judiciously….only when we are convinced that the new pathology is better than the pathology it is replacing….to put it bluntly. Remember the first maxim of the Hippocratic Oath….first do not make it worse…err to paraphrase “do no harm”.
All well integrated dental implants possess pockets… thus what you say is true, “If you have pockets when your implant is healed you have a problem.” Every dentist who places implants should recognise that they have created problematic pockets that they must check regularly and maintain at status quo as far as possible. It is not nonsense, it is a histologic fact that we self enthroned “implantologists” should accept and therefore treat responsibly. The alternative would be neglect with the accompanying consequences.
Regards.
Dr K.F.Chow
*
December 15th, 2009
Dear osurg,
“Iatrogenic”, according to Webster’s is defined as, “induced inadvertently by a physician”.
When we insert a dental implant into the bone and gums, we create a pocket around the neck of the implant as it traverses through the gum and into the oral cavity. This pocket is different from the normal gingival sulcus that is found around a normal tooth. When the gingival sulcus become diseased due to infection, trauma or abnormal immune response……it becomes inflamed and deeper and the diseased state is then called a pocket. I call the corresponding sulcus around the dental implant as it emerges into the mouth a pocket because it is not normal but a pathology. In this case the pathology is physician-induced and therefore iatrogenic!
If we examine the pocket around the implant histologically, it is a vast difference from that of a normal gingival sulcus. There are no true fibrous attachment like on a real tooth, only a pseudo-attachment and connective tissue that contains a higher number of defense cells than normal.
Yea, everytime we place a dental implant, we create a pocket….. a pathology…yep…..a diseased state. It is a fact that we must recognise so that we will use dental implants judiciously….only when we are convinced that the new pathology is better than the pathology it is replacing….to put it bluntly. Remember the first maxim of the Hippocratic Oath….first do not make it worse…err to paraphrase “do no harm”.
All well integrated dental implants possess pockets… thus what you say is true, “If you have pockets when your implant is healed you have a problem.” Every dentist who places implants should recognise that they have created problematic pockets that they must check regularly and maintain at status quo as far as possible. It is not nonsense, it is a histologic fact that we self enthroned “implantologists” should accept and therefore treat responsibly. The alternative would be neglect with the accompanying consequences.
Regards.
Dr K.F.Chow
*
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