“What about them implant things?”

Today’s blog post is going to be an overview of dental implants. I won’t go too much into specifics of types, the science etc because it’s a bit irrelevant, many boffins in many Scandinavian labs have done all the work for us and also, I  have no idea what half of the publications related to said science are on about.

I will split the topic into 2, what they are and what they can be used fo and in whom, then will do a part 2 explaining what is involved in their placement, aftercare, lifespan etc so stay tuned for that!

Shall we begin? Good.

What are they?

The Association of Dental Implantology UK (ADI) define implants as “a substitute for a natural root and commonly it is screw or cylinder shaped”. The actual object called the "dental implant" refers to the bit that is in the bone. Other components can be added/ attached to make the implant functional, for example, something called an abutment can be screwed on top, which passes through the gum and allows prosthetic (fake) teeth to be attached. See helpful pictures below.

Why would you need them?

So, you find yourself in the situation where you are either already missing, or are about to lose either 1 tooth e.g. you got caught in a drunken brawl, you ate too many sweets or in fact several teeth, for instance due to dental disease or following trauma (often horse related) or after removal of tumours etc. 

Placement of implants after cancer surgery is much more involved because not only are the teeth often missing, but the disgusting thing takes most of either one or both jaw bones with it and so extensive rebuilding is necessary before implants can be placed therefore making it much more complicated and beyond my limited realm of knowledge and so we shall stick to the “I haven’t brushed my teeth for 20 years and would now like you to fix it for me” causes of tooth loss.

How do they work and what can they be used for?

This seems a fairly obvious question however there is a lot of confusion of what implants can do. They are the closest thing to a natural tooth that can be provided by a dentist however they have several limitations. They can be used to replace individual lost teeth, in the majority of cases this is front teeth.

There is a lot of panic about losing and replacing of back teeth. Obviously if you have one of those smiles that shows every single tooth in your mouth and beyond, or have one of those laughs where you can see your epiglottis then the concern about missing a tooth is understandable. Fortunately most people don’t have this problem and so if you lose a molar tooth, there is actually no need to replace it. Especially with something that costs a minimum of 2 grand.

***As a side note if you come across one of those adverts promising 15 implants for the cost of a Mars bar, I would stay well away. I would consider dental implants in the same way you would think about other implants – hip replacements, breast implants etc and if you wouldn’t go to a rat infested converted house to have those done on the cheap, then you shouldn’t have your teeth done in the same situation. I think because they’re teeth people believe that the same standards are care aren’t necessary, only takes 5 years to be a dentist and that, surely my beautician could do it? The answer is no. Obviously. Mainly because if something goes wrong, its’ your jaw and your head. There is limited bone and so any infection caused by dodgy placement (bearing in mind there is a risk of infection even under pristine surgical conditions and a skilled operator) means that you are at risk of losing significant portions of your jaw bone and at this point, we can’t fix it. Mini rant over. Let’s continue

The only feasible reason for replacing a missing back tooth is to stop over-eruption of the opposing tooth, that is to say when the tooth that is biting against the one that is lost grows out of the gum and into the space. It is a very rare case that a tooth in the mouth ONLY comes into contact with 1 other tooth when biting, usually they touch 2 or 3 depending how you bite and for this reason usually over-eruption won’t occur.

Let’s see if a picture helps…

 Over-eruption means that the bit of the tooth that usually sits under the gum line is now exposed to the mouth. In terms of potential consequences this can look a bit unsightly, but again it would depend on your smile and what is shown. If you only see it in the mirror when you’re looking at a demented angle whilst stretching out your cheek then it really won’t affect your life. The other potential problem is that the bit of tooth under the gum line doesn’t have the protective enamel layer and so can be sensitive but again this can be dealt with in other ways that doesn’t involve damaging any teeth by placing bridges or burning a hole in your wallet.

Implants can also be used to replace multiple teeth either as a way of acting as an anchor for a bridge, which thus will replace 2 teeth, or to have several implants to more effectively hold in a denture.

Implants are NOT used to replace every tooth in the mouth. If you have no teeth left, then you need a denture. End of. The stabilisation of a denture CAN be improved by implants.

I emphasise word can for the following reasons. Fortunately some clever people have done some research so I can insert that now…

Assunção et al found that “Although the stability of the mandibular (lower) implant-retained denture was enhanced compared to a conventional denture, the quality of life and satisfaction levels were similar for both the groups.” i.e. the groups of people with and without implants felt equally happy (or in fact unhappy) with their dentures.

Allen et al found that “Subjects who received implants that replaced conventional complete dentures reported significant improvement after treatment, as did subjects who requested conventional replacement dentures” i.e. simply having some sort of denture was more important/life changing than having implants to hold a denture in.

Basically, implants are not the be all and end all of tooth replacement.

So, that’s what they can be used for, how about what they actually are.

	For this reason, one of the risks of having implants placed is that if they fail, it is often due to damage to the bone surrounding the implant rather than the implant itself as the metal implant is far stronger than the bone it is encased in and in a fight, the weaker one loses. This is the same reason by post crowns fail – the post is stronger than the tooth it is stuck in, so rather than the post breaking, the tooth does instead. I will go into this more in the second part of this blog. Multiple implants to stabilise dentures work in a similar way but takes slightly more careful assessment as it is not a case of plonking an implant in where a tooth has come out. The position and placement of the implants in order to best retain a denture has to be worked out and will be different in every person.

  

As you can see from the above pictures, this particular patient has 4 implants. They can be left as the implants alone onto which the denture clips. Or the implants can be connected with a bar and the denture clips onto this. Sometimes fewer implants will be placed etc etc and this will all be decided by the implant-surgeon.

Below you can see how denture clips into the implants. This particular case does not have a bar whereas the one above does.

In the final bit of this blog post I will quickly go over who is not suitable for implants. Of course you will most likely be able to track down someone somewhere who will place the implants without asking questions. As I said earlier, if you like taking risks with your health and in fact life, go ahead. If not, go to someone who actually knows what they’re doing who will tell you the following.

Contraindication	Why
Smoking	Smoking reduces blood circulation in the mouth and suppresses the immune response in the mouth, what this means is that healing in smokers is crap. As healing is necessary for implants to work (as the bone needs to fuse around the implants) it is highly reduced in smokers. Thus infections and fusing of the implants is highly reduced. You may also experience more pain from the procedure and this pain could last for longer. It is also possible that the implant will never heal and this could leave you in constant pain, resulting in the removal of the implant. Finally, long-term smoking affects how dense the bone is meaning that finding suitable strong enough jaw bone is more difficult.
High alcohol use	Alcohol, like smoking, seriously affects healing and thus can lead to implant failure.
Gum disease	Number one, gum disease can destroy bone. No bone = no implants. Simples. Even if enough bone is found to put an implant in the first place, gum disease will inevitably lead to its failure through the same bone destruction.
Clenching and Grinding teeth	As briefly mentioned above, the implants are not natural shock absorbers like teeth are and so any excess force, like clenching and grinding of the teeth, can damage the crown on top of the implant and potentially the base of the implant as well just as clenching and grinding can damage natural roots.
Weakened Immune System	Implant placement requires an operation. While it is a relatively minor operation, any reduction to the immune system normal responses can lead to infection. Weakened immunity can occur naturally with age, due to chemotherapy, AIDs, cancer, steroid therapy, medication following transplants, Diabetes etc. Of course this will be discussed during consultation and whilst having these conditions/taking those meds does not completely rule you out from having implants, certain modifications to treatment might have to be made
Bisphosphonate Medication	Bisphosphonates are a type of medication taken mostly for osteoporosis, but also for conditions such as Paget’s disease, bone cancers, metastatic cancers. They basically alter the way that bone heals and for that reason, anything that “damages” the bone in patients taking these medications can lead to devastating infection.
Unsuitable bone	For example very thin bone. While it is possible to bone graft, move the sinus to create more space etc this is far more extensive treatment. This is particularly irritating when people come in, you tell them they need a denture, or that we cannot fix their dentures to make them like normal teeth. The automatic response of the patient being “what about them implants?”. If you have enough teeth missing to need a denture, you need a denture. If your dentures drop out because you have no bone left, you can’t have implants without a whole tonne of extra surgery.

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So that’s all for today folks!!!

Feel free to ask any questions and remember to check back in a couple of weeks for details of exactly what is involved in implant placement and sadly, things that can go wrong!!

References and that..

Allen, McMillan, Walshaw,  A patient-based assessment of implant-stabilized and conventional complete dentures The Journal of Prosthetic Dentistr Volume 85, Issue 2, February 2001, Pages 141–147

Assunção WG, Zardo GG, Delben JA, Barão VA. Comparing the efficacy of mandibular implant-retained overdentures and conventional dentures among elderly edentulous patients: satisfaction and quality of life. Gerodontology. 2007 Dec;24(4):235-8.

Chee & Jivraj  Failures in implant dentistry British Dental Journal 202, 123 - 129 (2007) 

http://www.adi.org.uk/public/implant/whatis.htm

http://www.clydedental.com/dental-implants-glasgow.html

http://www.philipfriel.com/implant-retained-dentures-gallery.html

http://kumarandentalclinic.com/Missing%20Tooth.htm
http://www.philipfriel.com/implant-retained-dentures-gallery.html

http://en.wikipedia.org/wiki/Dental_implant

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Sedation

“Can’t you just put me to sleep to do that?”

Try to stay awake for this week’s topic…sedation. Insert drum and symbol noise here post awful joke.

There is a lot of confusion over methods of pain and anxiety relief used by dentists. This mainly comes from back in t’ day when regular high street dentists, officially known as General Dental Practitioners or GDP’s happily knocked people out to carry out dental treatment.

In 1998 the General Dental Council acted to construct more stringent standards for the use of general anaesthetic for dental treatment as sadly, several people popped their clogs in the dental chair. It endorsed the need for Conscious Sedation provision rather than the continuing provision of General Anaesthesia as a demand led service i.e. for everyone who came in needing a tooth out, a filling, a check up, would no longer automatically receive general anaesthetic as standard.

Although the publication of the GDC regulations  was followed by a substantial reduction in the use of general anaesthesia for dental treatment, two further deaths occurred outside hospital following general anaesthesia for dental treatment. Following several more rather tedious but nevertheless important reports, a final set of regulations were developed which state that “by 31 December 2001, all general anaesthesia for dental treatment should be administered in a hospital setting with critical care facilities.

This led, positively, to an increase in the use of sedation. Sadly, the dentists of yesteryear – yes even as recently as 2001 – were not so good on the communication front and either through this or through lack of knowledge themselves did not adequately explain to patients the difference between general anaesthetic, aka being knocked out, being put to sleep, and sedation.

For this reason we still on a daily basis see patients booked in on clinics to receive sedation for their dental treatment who either a) are unsuitable for sedation (I will explain further below, these people are usually weeded out at the consultation appointment but some still manage to wiggle through the net) OR b) believe they are going to be asleep i.e. have general anaesthetic for the procedure,

Why does it matter? I hear you ask. Well in some cases you are right. Why some people feel the need to be asleep to have a filling when others will happily have half their face hacked off without even a local anaesthetic is a mystery however our friends at the GDC state “dentists have a duty to provide and patients have a right to expect adequate and appropriate pain and anxiety control”. In some cases, due to general or mental health issues, or in fact the nature of the dental procedure alone, local anaesthetic simply is not enough.

Therefore there are several options ON TOP OF local anaesthetic than can be considered. The reason I slipped onto the old caps lock button is because sedation is not the be all and end all. It helps you relax, stay calm, prevent certain stress-related illnesses from escalating during treatment, it does not however provide complete pain relief and so local anaesthetic – yes the one via the needle – is still vital and patients need to be made aware of this otherwise you will find yourself in front of the not-so-friendly GDC being accused of assault.

How we can help

Here is the wordy bit. In order to eliminate confusion caused by the aforementioned poor communicators, we now refer to sedation as “conscious sedation” purely because you remain fully conscious for the entire time. Yes that’s right, you are not asleep, in a coma, and in fact remain fully in control of your body movements including the very important (if not slightly annoying) gag reflex, ability to open and close the mouth etc.

Here is exactly what I said above but in nice technical terms;

“conscious sedation is a technique in which the use of a drug…produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained throughout the period of sedation. The drugs and techniques used to provide conscious sedation for dental treatment should carry a margin of safety wide enough to render loss of consciousness unlikely.”

Delivery of conscious sedation comes in several forms – inhalation i.e. you breathe in the drug, or intravenous i.e. the drug is given directly into the bloodstream.

Inhalation Sedation

The drug you inhale is the same thing they give pregnant women when giving birth – laughing gas known as Nitrous Oxide. This chemical has the added quality over intravenous sedation of providing pain relief when inhaled. The American Academy of Paediatric Dentistry (AAPD) helpfully describe it as a colourless gas with a faint, sweet smell. It is an effective analgesic (pain relieving)/anxiolytic (anxiety relieving) agent causing central nervous system (CNS) depression and euphoria with little effect on the respiratory system. Translation: it makes you calm and happy without compromising any breathing reflexes or causing harm to the lungs or airways which is particularly important in people with things like asthma, where irritation of the airways can cause problems.

Pros	Cons
Quickly excreted from lungs – so effects wear off rapidly	Need for flow of pure oxygen after delivery of nitrous oxide as it leaves the blood stream much quicker than oxygen can replace it. Not really a disadvantage as 100% oxygen feels awesome and is automatically available wherever inhalation sedation is being given
No airway irritation	Feeling of loss of control
Nitrous oxide is absorbed rapidly, allowing for both rapid onset (two to three minutes)	You have to wear a mask in order to breathe the gas, anyone suffering from claustrophobia may struggle with this
It causes minimal impairment of any reflexes, thus protecting the cough reflex however has the added benefit of reducing very strong gag reflexes allowing certain treatment to be carried out that otherwise the patient may not be able to tolerate e.g. impressions	You need to be able to breathe through your nose, therefore if you have trouble with this e.g. broken nose, a cold, then you are unsuitable for this type of sedation
Extremely safe when used correctly	For the same reason as above, if treatment required needs us to be near your top front teeth, the mask gets in the way and so is not suitable
Extremely effective at reducing anxiety/ increasing tolerance to dental procedures particularly long or more difficult treatment.	It does not work alone. That is to say, the drug is not powerful enough used by itself to relieve all anxiety. It requires reassurance and “behavioural management” to be effective.

Who is it suitable for:

1.    Anxious patients. It is important to ascertain the reason for anxiety. As I mentioned above, it is still necessary to have local anaesthetic injections (yes, the dreaded needle) with ALL types of sedation and so while you care less when you under conscious sedation, if the fear of needles is extensive then the patient will be unsuitable for treatment under sedation.

2.    A patient whose gag reflex interferes with dental care;

3.    Patients where good, effective local anaesthesia cannot be achieved e.g. heavily infected teeth, low pain threshold

4.    A cooperative child undergoing a lengthy dental  procedure.

5.    Patients will well controlled diseases that can be worsened by stress e.g. angina, asthma

Contraindications for use of nitrous oxide/oxygen inhalation may include:

1.    some patients with chronic obstructive pulmonary diseases (COPD) – certain tests will be performed before placing a patient on a list for inhalation sedation, and the results of these tests will determine whether or not patients are suitable

2.    severe emotional disturbances. As mentioned above, the inhalation sedation does not work alone in reducing anxiety or making a patient feel like what you are about to do to their teeth is within the realms of something they can tolerate. Certain mental health disorders are too difficult to manage using the techniques of inhalation sedation

3.    drug-related dependencies. This includes alcohol as the metabolism of the drug, i.e. the way it works is affected heavily by certain drugs and alcohol.

4.    first trimester of pregnancy. Ideally we avoid inhalation sedation but it is still preferred over general anaesthetic so it is taken on a case by case basis.

5.    Severe heart disease, again, as with the respiratory problems, the results of pre-op tests will give us an idea of the level of disease and therefore whether sedation is appropriate

6.    Blood problems – Including factor deficiencies e.g. haemophilia, nutrient deficiencies e.g. anaemia

7.    As mentioned before , anything that prevents or makes it difficult for a patient to breathe through their nose which could be as simple as a current or recent cold.  

Now we have gone through all that, which involves enough paperwork to fell a small forest, if you are deemed suitable for sedation there are certain things that you must or must not do.

Oh by the way, this is what it looks like

 

See, even children can do it. You just breathe in through the nose, and out usually through the mouth because it is open for us to do the treatment. It is quite tight fitting and you feel a bit like a horse with a nose bag, but you are being pumped with the wonder that is nitrous oxide, so you couldn’t care less.

Some people would describe the feeling of receiving the sedation as like “being a bit drunk”. As a health professional I of course cannot comment on this but a friend told me a the warm glow after a few glasses of wine comes pretty close to the feeling of sedation.

Dos and Don’ts

1. Don’t starve but don’t stuff yourself either. Some people say that inhalation sedation makes them feel a bit sick and a full stomach won’t help with this feeling. A light meal a few hours before treatment is perfect.
2. A responsible adult escort must accompany the patient home from the dental surgery and assume responsibility for the patient’s post-sedation care.
3. Wherever possible arrangements should be made for the patient and escort to travel home by private car or taxi rather than public transport. Where this is not possible, the escort must be made aware of the added responsibilities of caring for the patient during the journey home.
4.  No alcohol 24 hours before AND after the sedation.
5. Take your regular medication as  normal as this will have been factored into the decision of whether you a patient is suitable for sedation and so there is no need to stop if you have been deemed appropriate.

Intravenous Sedation

This involves use of drug called Midazolam, and less frequently Propofol.  This I suppose could be considered as a slightly stronger form of conscious sedation and is often the culprit which causes confusion between sedation and general anaesthetic. The drug/magic potion is given via a cannula in the back of the hand/inside of the elbow which is the same as with general anaesthetic, hence the mix up.

 

Despite the needle only being present for a matter of seconds, a severe needle phobia will also rule out intravenous sedation alone. As with inhalation sedation, local anaesthetic injections will also be required after the sedation agent is given. Usually by the point people are happy for you to take a pneumatic drill to their face but the inserting of the cannula on someone particularly anxious can be very stressful and if this is the case then they are unsuitable for this form of anaesthesia. In some cases, inhalation or oral sedation (a tablet) can be given prior to the insertion of the cannula and this can often be enough to alleviate the patient’s worries about needles enough for sedation to be given.

Because of the drug given for IV sedation, there are a few more contraindications for this type of sedation vs Inhalation.

The same reasons for giving inhalation sedation also apply for IV sedation however a few more can be added, for example, patients suffering from epilepsy or Parkinsons disease would benefit from treatment under IV sedation as the drug given for sedation has strong action against involuntary movements for instance those that occur during an epileptic seizure.

Who IV sedation is NOT suitable for.

1.    Very young or very old patients. The reason for this is that the drug is broken down by the liver, kidneys etc and if these are not functioning at the correct level the patient can have a very unpredictable level of sedation. The same applies for patients with severe liver or kidney disease (including alcoholics who may have a poorly functioning liver without knowing it)

2.    Pregnancy (you literally cannot do ANYTHING fun when pregnant)

3.    Severe hormone issues e.g. thyroid disease, poorly controlled diabetes, adrenal insuffiency treated with steroids

Whilst this does not rule out patients from receiving IV sedation, certain medications amplify the effects of sedation and so the delivery of the drug will need to be modified. The list of drugs is fairly extensive but includes:

1.    Antihistamines (e.g. for allergies including hayfever)

2.    Antihypertensives (blood pressure)

3.    Alcohol

4.    Opioid drugs  – the legal or illegal kind

5.    Anti epileptic drugs – because they often have the same action as midazolam used for sedation

6.    Anti depressants

7.    Obesity. For several reasons.

a.    Finding a vein

b.    Unpredictable metabolism (breaking down and using )of the drug by the body

c.    Difficult monitoring of breathing rate, heart rate etc which is VITAL throughout sedation

d.    Difficulty in treating medical emergencies e.g. if CPR is required

8.    Blood disorders – haemophilia, thalassemia, sickle cell anaemia etc

IV sedation makes you feel a bit more drunk than with inhalation sedation, but again, all within the boundaries of the nice happy warm place before you decide late night karaoke/snogging your boss is a good idea.

The added benefit of IV sedation is that is SOME people it causes loss of memory for the time that the sedation was given. Whilst this is beneficial sometimes because it means the patient may not remember a possibly not so nice bit of dental treatment, it also means that the patient may not remember how well they coped/how calm they felt, and so every time they have sedation, their fears remain the same because it feels like the first time even after 50 attempts. I must stress that whilst this amnesia occurs a lot, it cannot be promised, and some people remember everything.  

The Dos and Don’ts remain relatively the same. No alcohol. Escort is required. However because IV sedation takes much longer to wear off and be completely eradicated from the body, extra care has to be taken for 24 hours. This means no signing of important documents, no cooking (beyond a microwave ready meal), no looking after children, no driving. Therefore, the responsibilities of the escort that a patient chooses are greater than with inhalation sedation.

As with inhalation sedation, starvation is not recommended before IV sedation however we recommend not to eat for 2 hours prior to Midazolam sedation, or 6 hours before use of Propofol.

Again, whilst there seems to be a long list of dos and don’ts in summary. Conscious sedation implies that the patient has:

• Minimally depressed consciousness

• Ability to maintain open airway

• Protective reflexes maintained

• Response to physical and verbal stimulation (European Archives of Paediatric Dentistry)

 

i.e. YOU ARE NOT ASLEEP. NOT EVEN A BIT. NOPE. NOT EVEN DOZING.

Sedation is an extremely useful tool in treating lots of different people for lots of different reasons. For most of us it is given as an option for taking out wisdom teeth because this can often be a more extensive procedure than having a scale and polish so do not be afraid to ask to be referred for it!

Where I borrowed stuff from

General Anaesthesia for Dental Treatment in a Hospital Setting with Critical Care Facilities, Chief Dental Officer, 31 May 2001

GENERAL DENTAL COUNCIL, Maintaining Standards, paragraph 4.8

Scottish Dental Clinical Effectiveness Programme Conscious Sedation in Dentistry Dental Clinical Guidance Second Edition 

http://www.aapd.org/media/Policies_Guidelines/G_Nitrous.pdf

http://www.cancerresearchuk.org/cancer-help/about-cancer/treatment/chemotherapy/having/iv-chemotherapy

http://ccnmtl.columbia.edu/projects/aegd/pdf/rationale-chapter21.pdf

http://www.dstg.co.uk/standards-in-conscious-sedation-for-dentistry/

http://www.eapd.gr/dat/5CF03741/file.pdf

http://www.saad.org.uk/documents/conscious-sedation/

http://www.sdmag.co.uk/index.php/articles/pm_article/inhalation_sedation/