Tubules Family: Study Club Directors

So What's New?

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• We all learn at dental school that amalgam has a longer lifespan than any other direct material, with 42% still in place after 15 years! However, some of the short term data is surprising, with 10% failure rate after 1 year and 20% after 2 years. 
• Overall, the evidence shows that there is around 7 years difference in survival between small occlusal amalgams and large MODs.
• The Minamata Convention is 2013 aimed to phase down the use of mercury containing products globally by setting national objectives for caries prevention, promoting cost effective and clinically effective mercury-free alternatives and promoting research and development
• This phase down is not limited to just dental amalgam, but to also other products such as thermometers and fluorescent lighting tubes
• There have been some Randomised Controlled Trials (RCTs) to shown there are no problems caused in children after having dental amalgams placed
• BUT if you remove an amalgam, high levels of mercury can be released into a patient's blood so you should use rubber dam and high volume suction
• Advantages of amalgam include: cheap and easy to use, technique tolerant, good life span and less moisture sensitive BUT it is not adhesive and is not tooth-coloured
• Indirect alternatives such as gold, cast alloys and porcelain are expensive
• GIC needs more development in order for it to be a good amalgam-alternative as it can be dissolved but it could be considered as a long term provisional which can be resurfaced with composite when it wears
• Due to composite being an adhesive, a study has shown that an occlusal cavity removed only 5% of the tooth surface in comparison to 25% in amalgam
• Studies have shown that failure rate per annum for composite is around 2%
• A main concern in composites is its polymerisation shrinkage although ways around this have been explored such as increasing the filler load, bulk fills and high molecular weight resins
• On average, a posterior composite does take 2.5X longer to place than an amalgam, so perhaps bulk-flow materials should be considered as alternatives
• Some concerns with bulk flow materials include C factors leading to increased sensitivity and stress, poor shade selection and costs. 
• There needs to be more development in finding an ideal alternative to amalgam which is self-adhesive, low shrinkage, with good physical properties, is wear resistant, is quick and easy to place and non-toxic

Make sure you tune in for the next #TubulesLive event on the 15th October! Let me know your thoughts on the phase down of amalgam in the section below!

To see my posts about previous #TubulesLive events see here. 

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• Every dental practice should have a business plan which is not just a file full of spreadsheets and figures, but a strategy to make the most out of their business
• Similar to the Wheel of Life (which I have talked about in one of my previous posts), Laura has her Wheel of Business with 7 elements to it which contribute to a successful practice

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Sinus lift augmentation and bone graft

So why do we need bone for implants?

1. For the stability of the implant for primary placement but also during functional activity
2. To create bone contour for the planning of an ideal prosthetic restoration
3. Stability of peri-implant issues in the long term i.e. the volume and vascularity of bone which does not resorbs

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• Bonded restorations (either ceramic or composite) can be BIOMIMETIC i.e. they can mimic the natural appearance of the tooth tissues
• According to some studies, the 10-15 year survival rate of these restorations is similar to that of conventional full coverage restorations
• The difference is not the lifespan, but what happens when the restoration fails. 
• Very few failures with bonded restorations are catastrophic failure compared with conventional prepared restorations as you are preserving more of the tooth tissue 
• You can produce a more aesthetic outcome, not only because the restoration is tooth-coloured, but you are also preserving more of the natural tooth
• The key pillars of tooth preparation are:

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This Maryland bridge that I provided for a patient recently was a definitive restoration

• Maryland bridges or even conventional bridgework can be used in interim periods, especially when providing implant work
• The material used can be heat-cured acrylic for short term replacements, or longer term composite bonded to metal work could be used
• There is also the option of using the extracted tooth for the pontic as long as the tooth is intact enough (usually more useful for periodontally involved teeth)
• If using the patient's own tooth, you can have the metal work made in the lab and then bond it to the tooth using Panavia after you have performed a rudimentary root canal treatment in the coronal portion to prevent discolouration
• To make decementation easier, you should use a smaller bonding area on the tooth and create a bevel coronally on the metal wing so that you have an application point for the chisel on removal
• Cement with permanent cement e.g. Panavia and due to the bevel you will have a greater cement lute than normal which you may need to remove with an ultrasonic prior to applying the chisel
• Remember to sharpen the chisel every time you use it as the autoclave will blunt the surface
• There is no need to cement the Maryland under Rubber Dam as this is it a provisional restoration
• Other options for adhesive bridge provisionals include Rochette bridges or using GIC as the cement 
• Always use a floss tie when attempting decementation as a safety measure
• Top tip to remove excess cement on the abutments is to use a fluted Tungsten Carbide bur carefully. Do not press hard as this will remove enamel
• Another way to remove excess cement is with an ultrasonic which can be safer but takes longer
• If removing cement from the bridge over the sink, remember to put the plug in the sink!
• To remove residue and get a cleaner impression, use a cotton wool pledget soaked in chlorhexidine 
• For a more stable bite record use Beauty Wax reinforced with metal foil which prevents distortion n transit to the lab
• When removing conventional cantilever bridges, try to remove with a Towel Clip and if that doesn't work use a Bridge remover with smaller and then bigger taps to break the cement
• When designing the occlusion for the bridgework, try to create a static single contact on the abutment and none on the pontic
• Bond failures with Marylands can either be due to poor treatment planning or poor execution in cementation
• If the debond occurs and there is no cement on the bridge, that means that the metal wing was not prepared enough i.e. sandblasted prior to cementation
• If the debond occurs and there in no cement on the tooth, that means that there was a moisture contamination on cementation
• For a good aesthetic result, ask the lab for an ovate pontic and for 0.5mm gingival relief on the cast itself

• CBCT can be used in both implant dentistry and oral surgery to help both with diagnosis and treatment planning
• 2D images such as DPTs can be misleading sometimes as it only gives a flattened view of a 3D object
• You can use CBCT to scan patients as well as prostheses to treatment plan cases - placing gutta percha in points in the denture can help locate the prosthesis. 
• Ideally you need around 4-5mm of sound bone to place an implant - CBCT can help you determine the amount and quality of the bone present
• If you don't have enough bone to place an implant, you can consider angled implants, zygomatic implants or extensive bone grafts or sinus lifts
• The UK guidelines of CBCT are containing in the HA-CREC-010 document
• When considering performing or referring for these images, you need to adhere to the IRR (99) and the IRMER (2000) guidelines 
• Usually in order to be a CBCT practitioner, you will need at least 11 hours of training 
• When taking a CBCT you must justify the reason why you need to take one and specify which area you need to see
• Record the justification and the report on the image fully in your notes. Dictated notes have been deemed contemporaneous
• You must also perform a quality assessment if you take CBCT. At least 95% need to be of an acceptable standard. 
• Unlike conventional dental radiographs, the quality assessment is only broken down into acceptable and unacceptable (< 5%), due to the scattering effect of metallic restorations
• A small Field of Vision (FOV) CBCT usually amounts to around 2-4 times a DPT, whereas a large FOV amounts to 6-7 times. 
• Doses keep decreasing with the newer machines 
• Typical background radiations is 7-8 mSv a day, so a CBCT usually amounts to a couple of days worth of background radiation, although not all machines are the same
• Uses of CBCT in oral surgery include: assessment of ID nerve position in impacted wisdom tooth extractions, position of impacted teeth in relation to adjacent teeth to assess potential to damage, assessment of periapical pathology prior to surgical endodontics
• Uses of CBCT in implant dentistry include: assessment of bone volume and quality, proximity to vital structures e.g. ID nerve, mental foramen, sinuses, sinus assessment e.g. spicules, membrane thickness
• The software you can use with your CBCT scan can be integrated e.g. Galaxis, Carestream, Icat Vision, or a third party software e.g. Nobel Clinician, Simplant, Osirix
• You can use CBCT with digitial scanning system e.g. CEREC (please see the previous #Tubuleslive post to read about this) in order to plan the ideal position of the implants and create a drilling guide
• With proper planning you can avoid complications such as a sublingual artery bleed as a result of lingual wall perforation

A CEREC designed and milled Emax crown on the lower first molar.

• CAD/CAM has many applications in patient care: from CBCT scanning to the production of surgical guides and provisional restorations as well the final definitive restoration
• CEREC can be used conventionally to manufacture restorative extra-coronal restorations such as inlays, onlays and full coverage crowns. 
• These restorations are made on the same day, which means that there is no need for a provisional restoration and there is only one visit for the patient - this often increases patient satisfaction as they can watch the milling of their restoration sitting in the waiting room
• CEREC alongside CBCT scanning can be used in the diagnosis and planning of treatments and can be useful to help explain to patients their situation as a 3D image of their teeth and their surrounding anatomy can be generated.
• This 3D image gives a better diagnosis than conventional 2D imaging as you can accurately diagnose fractures, qualities of root fillings, periapical areas, the amount and quality of the surrounding bone and proximity to vital structures e.g. ID canal
• All the team can be involved in the diagnosis and planning stages of a patient's visit - appropriately qualified nurses and technicians can take the scans and place implants in the correct place on the scan. This can lead to more efficient use of a clinician's time
• Provisional restorations can be milled from composite blocks based on these planning stages to help plan the emergence profile of the restorations, shape the soft tissues as well as help the patient understand what the final restoration may look like
• CEREC can then be used to scan preps or the implant (either at the same stage as the surgery or delayed) so there is no need for impression taking
• Definite materials for implant crowns include Zirconia and Emax. Emax crowns can be milled in 12-13 minutes!
• If there are any issues with the provisional or definitive restorations, data has been stored electronically so re-milling is easy and there is no loss of information which can happen with an analogue system. 
• In order to introduce a CEREC or CBCT system into practice, you will have to invest quite a lot of money both in the equipment but also in yourself in terms of training. 
• These systems, despite the high initial outlay can help increase your turnover as you are not only providing a better quality of care for your patients, you can actually save a lot of clinical time so you can ultimately see more patients!

The lateral window technique for sinus augmentation prior to implant placement.

• Sinus lifts are one of the most common pre-prosthetic surgical procedures carried out in the UK
• The maxillary sinus (or antrum) is one of the 4 paranasal sinuses which enlarges with age and growth can be rapid following the loss of posterior teeth
• Paranasal sinuses are all connected which means that infection originating in one sinus can spread to the others. 
• The maxillary sinus is a quadrangular pyramid in shape and can vary in size significantly, even extending as anterior as the distal of the lateral incisor
• Some vital structures associated with the maxillary sinus include the facial artery and nerve, internal maxillary artery and the sub-orbital nerve
• Maxillary sinuses sometimes contain septa, which although they look like spikes on DPTs, are actually walls running that divide the sinus
• The sinus membrane is very elastic and thin (although this can vary), and can thicken on response to chronic irritation e.g. sinusitis, chronic periapical infection of maxillary molars
• Pathology of the maxillary sinuses include tumours e.g. ameloblastoma, or more commonly sinusitis
• Sinusitis is caused by a chronic irritant and can be viral, bacterial or fungal in origin.
• Contra-indications to sinus augmentation include: radiotherapy patients, drug addicts, smokers, presence of an oral-antral fistula, complex medical histories
• Patient suitability must be assessed in several ways:

The next #Tubuleslive event will be next week the 5th of January where I will be hosting my first event: CEREC integration in practice with Dr Colin Campbell.

Why not attend the live audience where you can get FREE CPD! Register online and I hope to see you there!

Have you had experience performing sinus augmentation in practice? Please comment in the section below!

To see my other posts about previous #TubulesLive events see here. 

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What is Dentinal Tubules?

Why should I join?

What's coming up in 2015?

In summary, joining Dentinal Tubules doesn't just give you access to hundreds of videos and resources, but it's a great way to network and learn from other dental professionals! I hope to see you at the live streaming events in London where you can get some FREE CPD! 

To join Dentinal Tubules click here. 

If you have any questions or thoughts please leave them in comment section below!

To see my posts about previous #TubulesLive events see here. 

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