Archive for category Uncategorized
Implant Risk Factors: Implant Fracture
Posted by admin in Uncategorized on February 20th, 2010
Any experienced implant practitioner would have seen a good number of failures. From a surgical standpoint, success rate can be well over 90%. It’s not difficult to achieve such success rates because all that is needed to determine success of the implant is osseointegration - the process whereby bone grows onto the implant surface and “fuses” with it. This implant can then be loaded with a crown.
What happens after loading? It’s just like what happens after marriage. Nobody can be certain as many factors come into play. There are patients with poor oral hygiene. There are patients who grind their teeth at night. There are patients who love to chew on bones to get to the marrow. There are patients who abuse their teeth in ways we can’t even imagine. Practitioners who handle restorations and follow up over a period of time will be able to tell you that implants restorations can be highly problematic over the long term. Some patients will be quite happy with their implant restorations. Some will need to see their dentist every few months for some adjustments. The most common problems are screw coming loose, gum inflammation, bone loss, exposed threads. Sometimes, we see porcelain fracture. Sometimes, we get fractured abutments, fractured screws and even fractured implants. Practitioners who have not had any of such problems on their hands probably haven’t done enough implants.
Yes, in spite of all the hype about implants lasting a lifetime, some implants do fracture after just 3 years and here is one of them. It’s one of the most uncommon complications and this is my first fracture case. As usual, the manufacturer blames it on everything except the product. But if we take a close look at the design of the implant, it is not difficult to see why this American implant might be more likely to fracture than other systems.
What wasx my reason for using this implant system? The patient has a deep bite. We’ve often been told that a fractured screw is the worst disaster you can face and implant screws are pretty small. This system does away with screws and employs a phenomenon called cold welding to hold the abutments inside the implant wells. We have been told by the experts that if biting forces were excessive, screws can break, but for this system, the abutments would just pop out. Replacing the abutments can be as simple as just tapping it back in place. They made it sound like an excellent system for patients who are bruxers, or in this case, someone with a deep bite.
Here with are with a fractured implant. The abutment post was still securely cold-welded to the fractured top part of the implant when the restoration was removed. The bottom tip of the fractured implant was still firmly embedded in bone. Something is not right. Let’s take a close look at the fractured cross section. This implant is 3.5mm in diameter. Most implants have tiny threads on their surfaces. This American system boasts of a radiator fin design and a whole list of merits based on it. However, if we look at the radiator fins - and this is the first time I had a chance to see the cross section of the implant I’ve been using for years, we’ll see that the fins run quite deeply into the body of the implant, unlike threads which only score the surface.
What is the implication? Instead of 3.5mm of solid titanium, we have only 1.6mm of solid titanium at the core beneath the implant well. This is shocking news to me. I didn’t know that the implant’s weakest point is that weak. True enough, the implant fractured at the 1.6mm juncture between 2 fins, just past the bottom of the implant well. Far from the system of choice for patients who are bruxers, this may well be the system to avoid in such cases.
In this age of compulsory continuing education where course directors and expert speakers can have vested interests in a system, dentists are as victimised as patients when fed with biased information from sponsors and manufacturers.
Sodas And Pancreatic Cancer
Posted by admin in Uncategorized on February 8th, 2010
WASHINGTON, Feb 8 - People who drink two or more sweetened soft drinks a week have a much higher risk of pancreatic cancer, an unusual but deadly cancer, researchers reported on Monday.
People who drank mostly fruit juice instead of sodas did not have the same risk, the study of 60,000 people in Singapore found.
Sugar may be to blame but people who drink sweetened sodas regularly often have other poor health habits, said Mark Pereira of the University of Minnesota, who led the study.
“The high levels of sugar in soft drinks may be increasing the level of insulin in the body, which we think contributes to pancreatic cancer cell growth,” Pereira said in a statement.
Insulin, which helps the body metabolize sugar, is made in the pancreas.
Writing in the journal Cancer Epidemiology, Biomarkers & Prevention, Pereira and colleagues said they followed 60,524 men and women in the Singapore Chinese Health Study for 14 years.
Over that time, 140 of the volunteers developed pancreatic cancer. Those who drank two or more soft drinks a week had an 87 percent higher risk of being among those who got pancreatic cancer.
Pereira said he believed the findings would apply elsewhere.
“Singapore is a wealthy country with excellent healthcare. Favorite pastimes are eating and shopping, so the findings should apply to other western countries,” he said.
But Susan Mayne of the Yale Cancer Center at Yale University in Connecticut was cautious.
“Although this study found a risk, the finding was based on a relatively small number of cases and it remains unclear whether it is a causal association or not,” said Mayne, who serves on the board of the journal, which is published by the American Association for Cancer Research.
“Soft drink consumption in Singapore was associated with several other adverse health behaviors such as smoking and red meat intake, which we can’t accurately control for.”
Other studies have linked pancreatic cancer to red meat, especially burned or charred meat.
Pancreatic cancer is one of the deadliest forms of cancer, with 230,000 cases globally. In the United States, 37,680 people are diagnosed with pancreatic cancer in a year and 34,290 die of it.
The American Cancer Society says the five-year survival rate for pancreatic cancer patients is about 5 percent.
Some researchers believe high sugar intake may fuel some forms of cancer, although the evidence has been contradictory. Tumor cells use more glucose than other cells.
One 12-ounce can of non-diet soda contains about 130 calories, almost all of them from sugar.
Killing A Tooth
Posted by admin in Uncategorized on January 23rd, 2010
We’ve all heard about root canal and it scares the hell out of people who don’t know anything about it. When they see pictures of “needles” (endodontic files) being poked deep inside a tooth, they virtually freak out.
“Over my dead body!”
Well, that’s if the pain from acute pulpitis doesn’t kill them first. So what is this thing called the pulp? Why should it be there in the first place?
Put simply, it’s that tiny shred of soft, bloody tissue encased inside the hard tissue of the tooth. When we do a root canal, we often tell patients that we have removed their “nerve”. The pulp tissue is more than just nerve, but calling it “nerve” makes it easier to understand. Nerve gone, pain gone. The pulp is actually made up of blood vessels, dentine-forming cells and of course, nerves. The function of the pulp is to “grow” the tooth. And this growth is mostly an inward kind of growth.
A tooth in a young person will have a large pulp chamber. We can say that they have “a lot of nerve”. That means that their enamel and dentine are relatively thin. As a person ages, the pulp deposits more and more dentine, pushing itself inwards. This function attempts to replace tooth substance loss from attrition, abrasion and other destructive forces our dentition has to deal with in fulfilling their masticatory functions. Hence, in the teeth of older persons, we will see smaller pulp chambers and thicker dentine.
Technically, a pulp would have already done its job when the root tip of the tooth is properly formed and a considerable amount of dentine has been laid out. With the kind of diet that most modern humans have, teeth do not wear out that quickly. Do we need the pulp to keep laying down dentine throughout our lives? Probably not.
So what’s the big deal about killing a tooth for a 30-year-old or even a 25-year-old patient? There are patients who walk into a clinic, presenting with mild attrition of a tooth but severe sensitivity on it. The tooth is still vital. Why kill it? The “natural” thing to do is to crown that tooth to protect the worn out areas. Sometimes, it works. Sometimes, it doesn’t. If the patient can afford to do both the root canal and the crown, then that would be ideal.
What happens if the patient only has $600? Well, if it’s the sensitivity that is killing the patient, then root canal is the only sure way to stop the sensitivity. And if the tooth is only slightly attrited, there is probably enough tooth structure to support it even after root canal treatment. I think we should go ahead and kill the tooth. Crowning is not any more conservative.
Another extreme, highly controversial and interesting case would be one of tetracycline staining. Take a look at these teeth.
To date, the most effective method to mask these discolourations is veneering. But in order to mask these deep stains, veneers have to be thick and opaque. When they are thick and opaque, they don’t look natural. Crowning may mask the discolouration well, but what about root canal?
Many people would be shocked by this suggestion and I’ve frankly not tried it myself, but practitioners who thought out of the box have reported very successful and “non-invasive” protocols which not only preserve valuable enamel, but produce highly aesthetic results. All that need to be sacrificed are the pulps of the stained teeth. After root canal is completed, very strong bleaching agents can be placed inside the non-vital tooth. While tetracycline may be virtually impossible to bleach through the enamel from the outside, there are pores located inside the pulp chamber which allow bleach to travel inside the dentine layer, effectively bleaching it. The beauty of this system is that aesthetics can be achieved with your original surface enamel (stronger than any porcelain) intact.
Would you kill 6 teeth and have them bleached from the inside? Or would you rather trim away part of your surface tooth structure and mask them with thick porcelain like below?
The Irony Of Updates
Posted by admin in Uncategorized on January 21st, 2010
I survived 2 days of lectures at a dental symposium held over the weekend at a hotel in Orchard. Usually, the best parts of such seminars are the food, the comfortable chairs and the chance to catch up with members of the fraternity.
Of course, I have already attended many seminars, conferences, meetings, symposiums or whatever the organisers call them. To be fair, this is not the worst and most time-wasting. Why am I talking about it in my blog? Because this particular symposium brought out a big irony of “updating” ourselves at compulsory continuing education seminars.
The whole rationale of making continuing education compulsory is to ensure that dentists don’t become dinosaurs. We need to be updated on the latest technology. Very few members of the public would argue against that. We are bombarded by new technology every day. Almost without thinking, we accept that the latest #$%&* Plus as superior to #$%&*.
Many people wonder what dentists use to “glue” their crowns on prepared teeth. The material you see above is one such cement. When I was a student, I cemented all my gold inlays with this cement. However, many young dentists would not have seen this cement, let alone use it. Of course, I don’t expect them to be very familiar with gold inlays either. Of course this cement can be used to cement other types of crowns. It’s just that newer, sexier, hi-tech and much more expensive materials came into the market and everybody forgot about zinc phosphate. In some developed countries, you shouldn’t even tell people you have used zinc phosphate cement if you don’t want them to know how old and oudated you are.
In the first lecture of the symposium, the elderly speaker spoke on the development of dental cements over the decades. It was an enlightening history lesson. Some cements worked well. Some didn’t work so well, but dentists later found out why and managed to solve the problems. Some gave disastrous results. Dentists also found out why, but the they didn’t manage to solve the problems. Some of these disastrous innovations, strongly touted by some of the biggest and most reputable dental material manufacturers as the best cements during their time, quickly got pulled off the shelves when crowns broke and teeth fractured.
Dentists have been conned. Patients suffered and sued. I can’t say that I find the speaker very objective, but he does share some of my thoughts. If something has been working well for years, why change to something new and untested? Frankly, I have not even heard of some of the cements the speaker mentioned. And it’s certainly a case of ignorance is bliss. My patients ought to feel so fortunate that continuing education wasn’t compulsory back then. I would have attended one of those seminars, got conned into using those new products and done my patients a great disservice.
The big irony here, is that the “update” we’re getting here is telling us that all the cement “updates” we have been receiving all these years are not really “upgrades”. We wouldn’t have lost much if we had ignored them all and stuck with good old zinc phosphate.
The conclusion? Our speaker strongly advocates gold restorations and zinc phosphate cement. Some of these combinations have lasted 40 years in the speaker’s patients’ mouths. As a practitioner of cosmetic dentistry, I wouldn’t want to have any gold inside my patients’ mouths and I’m sure they won’t get mad at me if their crowns don’t last 40 years. But this speaker made a very valid point which the organisers and administrators of continuing dental education should take note of.
Not all “updates” are “upgrades”. Many, or should I say too many new dental products simply don’t work as well as their ancestors. Such guided evolution panders to the public’s insatiable appetite for new technology. As discerning professionals, we shouldn’t be so obsessed with the latest tabloid news. We can already see a confusing explosion of information and misinformation on the internet. How much of what is released is worth listening to? With a rigid 70 point criteria to be fulfilled in a 2-year period before your dentist can renew his practising certificate, are you not worried that he pays his way to be fed with misinformation which will cost you in more ways than one?
Dentists Not Enough?
Posted by admin in Uncategorized on December 21st, 2009
Dr L (a senior consultant at a well known local hospital) and I were neighbours. We virtually grew up together in the old neighbourhood of Queenstown. We had a lot in common as our parents were neither well-educated nor wealthy. We were athletic, but unlike the other boys, the two of us just didn’t like football and marbles. Our folks were good friends, especially our mothers. Once, the two ladies travelled to Australia together. They visited the outback and some beautiful farms and vineyards. Mrs L’s impression of Australia?
“It’s such a backward country. You drive for miles and can’t even find a single NTUC. Trees, grass and sheep. So backward. Not like Singapore where everything you need is within a shuttle bus ride.”
At first glance, Mrs L’s remarks are laughable and perhaps not even worth mentioning. You may not believe me now, but there is actually a lot that we and our esteemed decision makers can learn from Mrs L’s remarks.
According to one CNA report:
Singapore has only 1,300 dentists in active practice and the Ministry of Health (MOH) wants to increase this number by between 60 and 80 per cent over the next 10 years.
It is studying a proposal to allow foreign dentists from the region to practise and train here under an accreditation scheme.
There is one dentist for every 3,400 people here in Singapore, a figure that has lagged far behind developed countries.
Singapore produces 40 dentists a year and MOH hopes to ramp this up. It is considering accrediting private training centres to allow registered foreign dentists to treat patients while undergoing training.
A dentist to population ratio of 1:3400 is too low for Singapore because developed countries have a “healthier” ratio?
First of all, let’s consider Mrs L’s remarks about Australia where you can drive for miles in the outback and not come across an NTUC, let alone a dentist. Can you drive for miles off the expressway from one housing estate to another in Singapore and not be able to find a single dentist with an empty waiting room? Is dentist to population ratio a good guideline for what is excess and what is deficient?
The logic behind looking at absolute numbers is obviously flawed. Many established dentists have more than 5000 patients on record, many of whom are seen once in 10 years. In the developed countries, old folks must have dentures. And they do change their dentures every now and then too. Over in the developed countries, it’s also not too difficult for dentists to convince their patients to do root canals and crowns. A lot of such treatment is considered basic necessities and are covered by insurance.
Over here, our thrifty old folks make one set of dentures and try to make them last a lifetime and many young, educated people have not heard of crowns and root canals. There are numerous indications for crowns, root canals and implants, but indications are just indications. What is the reason for all that undone dentistry which dental practitioners encounter on a daily basis? Not enough dentists? Or just a lack of interest and/or knowledge on the part of the patients?
Still trust the numbers?
Unlike mom and pop shops, solo dental clinics are still able to survive because as far as dentistry and hairdstyling go, many people still value that personal touch from someone familiar. Apart from that, the small practices have little advantage over the big boys who often get free publicity by making news. Many existing small practices are already facing great challenges against the big boys. Increasing the number of dentists will only shrink the pie further and make things worse for small practices which are already struggling regardless of the favourable theoretical conclusion that can be drawn from the 1:3400 ratio.
Implant (No) Surgery
Posted by admin in Uncategorized on December 13th, 2009
Most implants are placed into bone which has already healed over the extraction socket. This requires surgery. The gums have to be cut, a flap retracted and bone has to be drilled. The retraction of a gum flap almost always results in some pain and swelling.
To make the surgery less invasive, some dentists do it flapless. In other words, they drill straight through the gums into the bone without cutting and reflecting a flap. After the flapless operation, the patient tends to feel less pain. However, flapless surgery is “blind”. The surgeon will not be able to see if there are any perforations beneath the gums. Where bone thickness is not ideal, flapless surgery may not be safe or even possible.
What about inserting an implant into an extraction socket immediately after the extraction? If possible, the advantages are obvious. First, the patient does not have to go through implant surgery at a later date. It is flapless and relatively atraumatic. It is usually a one-stage surgery where no further surgery is required to expose the implant. As implants take 2-3 months to integrate, placing it at the time of extraction shortens healing and restoration time.
What is not so obvious, is the technical difficulty of placing an implant into an irregularly-shaped socket. When you drill a hole into a clean wall, you can control the exact depth and width of the hole. When you drill into an existing hole, it’s very difficult to control the final shape and size of that hole. It is imperitive that the surgeon gets good primary stability and is able to place a wide, socket width healing abutment over the implant at the end of the surgery. The success of immediate insertion depends very much on the surgeon’s skill and experience. It also depends on the condition of the tooth.
Immediate placement is not recommended when.
1. There is pus and acute infection.
2. The tooth is very shaky with advanced gum disease.
3. Surgical removal of the broken tooth is necessary.
The conditions for immediate placement are very similar to the conditions for required for socket preservation with Alvelac bio-scaffold (see video here) . As long as the socket is walled with bone on all sides, immediate implant insertion is possible. Forget about socket preservation. The immediate placement of the implant provides socket preservation, fewer surgeries and shorter healing time without additional costs.
Shopping For The Cheapest Dentist
Posted by admin in Uncategorized on November 23rd, 2009
The internet allows people we have never met to become our patients. It often starts off with an enquiry. This is followed by a consultation, a discussion, treatment planning and finally the actual treatment is done. This source of patients is not to be under-estimated. It’s how we managed to build up a cosmetic dental practice. That was 6 years ago.
In recent months, however, we received a lot of enquiries from people who seemed like potential patients. This may sound like good news, but it isn’t. In the past when trust was easier to come by, a high percentage of people who contacted us via the internet did show up for consultation and treatment. Nowadays, enquiries are much harder to handle. Folks who seem interested try to settle the treatment plan, exact costs, guarantees and number of visits over a few emails. They don’t seem to realise that dentistry cannot be practised online. A lot of details of exact costs, procedures etc cannot be determined without an examination. Even with that, unforseen circumstances may result in a change of treatment plan. Insisting on precise figures is difficult at best and unreasonable at worst.
An example. How much does it cost to do a filling. $80. patient turns up with deep caries involving the pulp. This would require root canal treatment and it’s going to cost much more than $80.
“Can you guarantee that it’s only going to cost $80? No hidden costs.” comes the question by email.
Of course not! How can the dentist tell how bad your condition is and whether a filling is all you need? Don’t these folks realise that as far as I’m concerned, it’s their tooth that is hidden from me and not my costs which are hidden from them.
“I just want to do a filling. If you can’t guarantee that it’s not going to cost more than $80, then I won’t come.”
????????!!!!!!!!
So what if we quote reasonable charges. Some folks may be suspicious why Dentist A charges less than Dentist B. So these folks ask even more questions in an attempt to determine how reliable a dentist is without even turning up for consultation. Some of these questions are irrelevant and some can be downright weird. The more they ask, the more uncertain they become. Someone ought to tell them that the real answers to their doubts don’t show up very well on email. So usually, it back to cost factors. Cheapest practice wins. Not to say that the cheap practices are no good, but what about this thing called trust?
C, a colleague of mine has just been diagnosed with diabetes. His doctor? None other than our schoolmate in JC. The doctor is not an endocrinologist. He is just a GP, but C and his family has been seeing him since he started his own practice more than a decade ago. C’s entire family has not been seeing any other doctor ever since. No matter where they go or how much they charge or what additional tests, medications and procedures they indicate, their pool of loyal patients who see them several times a year follow them. It’s all about trust.
If there’s such a thing as doctor-for-life, is there such a thing as dentist-for-life? I’m sure there is. Quite a few have followed me all the way from Hougang. How do you choose a dentist-for-life then? Simple. Try out a few dentists for simple, non-invasive treatment like scaling. Pick one you like, show up regularly for scaling and develop a close patient-dentist relationship with him/her. He knows you. He recognises the importance of the relationship and is far less likely to do anything “funny” than someone who is seeing you for the first time. So what if there’s no Medisave in his/her clinic? So what if the clinic would only allow a 70% claim of surgical fees? Do you have to look for a clinic that allows a 100% claim (like mine) and shoot 100 questions at me because you don’t trust me? Please go back to the dentist you trust. Entertaining all these doubts, mistrust and reluctance to pay consultation fees is a waste of time for me.
Dental Implant Patient Education Video
Posted by admin in Uncategorized on November 23rd, 2009
Do you agree with everything mentioned in this dental implant video? You shouldn’t.
No Drill Can Fill?
Posted by admin in Uncategorized on November 23rd, 2009
Interesting, innovative new product called ICON. No drilling for initial caries which show early enamel penetration. There are some limitations which the manufacturer has already warned us about. There are probably many more which they either don’t know or are not telling.
Haven’t tried it out yet, but the price is pretty shocking. Difficult to be open-minded under such circumstances. Experience tells me to forget about it.
Tooth Engineering
Posted by admin in Uncategorized on November 18th, 2009
A Japanese group, led by cell biologist Takashi Tsuji of Tokyo University of Science in Noda, Chiba Prefecture, focused on tooth germs, the embryonic tissues that develop into teeth. After obtaining such germs from mouse embryos, they separated out two types of cells–epithelial cells and mesenchymal cells–and then recombined them into a new bioengineered tooth germ. The team then grew the bioengineered germs in a special culture for 5 to 7 days and transplanted them into the upper jaws of adult mice in the place of an extracted molar. New teeth poked through the gums after about 36 days and reached the proper size and alignment with opposing teeth for proper chewing after 49 days.
All indications are that the teeth function just like the real thing. They have the roots, inner pulp, and outer enamel of normal teeth and are just as hard, the team reports. Moreover, unlike dental implants, the regenerated teeth develop the periodontal ligaments that tie normal teeth to the supporting bone and the nerve fibers that give sensitivity to chewing pressure and other stresses. “We clearly demonstrated that the bioengineered organ germ could develop into a fully functioning organ,” Tsuji says
Tooth whitening kit ready in 1 hour
Natural looking, metal free crowns
Sleep through your dental procedure
Affordable dental implant restorations
Flexite, titanium, hybrid dentures
wisdom tooth surgery, Medisave claimable
