THE INCI-DENTAL BLOG

Hi guys, here is the case I did last Wednesday just to show my composite technique. The case is a 32 year old female who had caries in 25 distally well into dentine. Here are the shots of the case from start to finish.

Starting point 25d caries – it seems a definite shame to drill this tooth!!

Caries removal 25d and along the occlusal fissure (not a retentive key). Placement of rubber dam with clamp on 27, slit dam 26 to 23 with floss ligature.

Acid etch and rehydration of dentine. Wedgewand placed and sectional matrix strip followed by Compositight 3D-ring.

Flowable composite lining and proximal contact built up in an enamel shade of composite after burnishing of thhe sectional matrix.

Placement of composite in incrementally built up layers up to the cusp slopes starting with a dentine shade first and finishing with an enamel shade.

Finishing and polishing of the restorations. Pleasing contact point and the patient was very happy.

Feel free to comment! I’ll put an MOD case up illustrating the use of two rings as soon as I can.

Hello everyone. This is my first blog contribution so please take it easy on me! 

Working full time in practice at the moment I am ever more increasingly being asked to provide aesthetic restorations in posterior teeth. Most of these are replacements for oversized amalgams, often pinned and often cuspal coverage restorations. I spent the last few years experiencing difficulties during the actual placement and afterwards and I had started to dislike placing them. I began hoping patients would chose an easier alternative, like amalgam – something techincally less demanding! Has anyone else felt like this? I doubt I’m alone in this matter. I had started to accept that composites in posterior teeth had big limitations, not just confined to moisture control. 

I always used to find problems producing a restoration with a tight contact point and sometimes I’d achieve a slight gap that would be irritating to the patient and trap ‘bits of bacon’. I found people would often return complaining of sensitivity which seemed to take weeks to improve or settle if it did at all and I often felt the appearance could be better although I don’t think anyone ever complained about this aspect. 

It wasn’t until I moved practices 2 years ago after GPT that I got much more practice at doing them. I decided I couldn’t spend any more time being uncertain about my class 2 composites. At this point I decided I needed to invest time and money sorting my composite techniques out so that I could be confident that when I was doing a posterior composite on a patient that I was happy it would be predictable and of a good appearance. They are undoubtedly very technique sensitive and I think I have a few ‘rules’ regarding when class 2 direct composites are likely to do the job well or when I should be thinking about doing a restoration of a different material. I attended courses, bought some better equipment and more than anything just practiced! 

I used to use Aristobond (Cheap as chips by Wright Cottrell) a 5th generation DBA, rubber dam, wedgets, wooden wedges, a siqveland matrix. I soon realised this list of materials is inadequate. 

I’m interested in knowing how people do their composites and if there are any tips I can introduce in to my practice. There may also be a possibility that some of this may help others experiencing the difficulties I’m now seeing less and less of. 

So what have I learned? 

Rubber Dam 

* Rule number one. I think it’s fair to say rubber dam is essential. Some people have warm breath that will drench your mirror so how can you expect a moisture-free tooth surface. I prefer KerrHawe’s Optidam but I no longer have the luxury of this so I’m back to punching holes in a piece of green rubber and hoping they don’t tear. Whatever dam you use it’s my opinion that when you use it regularly you get so quick at putting it on that I now feel it saves me time, especially during endo, because there is no need to keep replacing cotton wool rolls and aspirating is easier. I do admit though that not all patients will tolerate it. 

Bonding Agent 

* A good quality bonding agent is needed. I sometimes use Tokoyama bondforce 7th generation bonding agent which is a self-etching system and the 5th generation Optibond Solo Plus and I have noticed very little difference in the incidence of problems with either. I don’t fully rely on the 7th generation DBA and as a result I still etch in the same way I do for the 5th generation. I used to, however, use a very cheap bond (not my choice) and experienced massive sensitivity issues and also found it could debond in some circumstances. I audited it and decided I couldn’t ethically use a cheap bond again – you do get what you pay for! 

Contact Point 

* Getting a good contact point is really important to a patient’s perception of a ‘good job’ and it is no doubt important to prevent food trapping and recurrent caries. It is depressing when you think you’ve done a great job of wedging a matrix band only to find you can floss far too easily once it has been removed. Of course if the contact point is poor the patient will return to complain or will certainly tell you at their next check up that they are trapping food. To me saying to patients ”unfortunately you’ll have to floss” seems like a cop-out even though they obviously should anyway. 

Shrinkage 

* Everyone knows composite shrinks and that building it up in increments can help reduce this. I remember Prof McCabe’s book suggesting building up in sloped triangles in order that contraction hopefully occurs in the direction of the walls of the cavity. The next layer would hopefully do the same but in another direction therefore in total reducing contraction more than a single ‘monobloc’ of composite. 

* Getting this right is really important to preventing post-op sensitivity and microleakage. 

I learnt that it’s best to think of composite shrinking by way of a formula: 

Factor of degree of contraction = number of bonded surfaces/ number of non-bonded surfaces 

By that idea an occlusal restoration would have a contraction factor higher than an MO. So if a large restoration is built up in increments whereby each layer to be light-cured is built up in contact with as fewer surfaces as possible then this will limit the overall contraction. This helps me plan which parts I’m going to build up first when looking at a cavity. 

My technique:      I will show a clinical case at the end of this article or in the next blog. 

I like to use a sectional matrix system and so I recently bought the Composi-tight 3D sectional matrix system from Garrison Dental – this is my newest toy and I’m over-the-moon with it. 

http://www.garrisondental.eu/ 

The video on the website is really good as it shows placement better than I can but it just shows the composite being magically ‘thrown’ into the cavity. I certainly don’t do this! 

I decided to go for this system because I used it on a course and I was blown away by the contact point it produces with its slick-band matrices – I struggled to even get floss down through the contact points afterwards. 

There is a great article on clinical composite tips in the November 2009 Edition of Aesthetic Dentistry Today by Rob Lowe “Clinical solutions to common problems faced when placing class 2 direct composites” which is definitely worth a read as it reinforced a lot of the tips I had picked up in the phantom head course I did and in practice. It also talks about gingival haemorrhage control by the use of Expasyl. 

You firstly place the rubber dam on the tooth you want to work on, the tooth behind and at least one tooth in front of it. I would use tied-floss or wedgets on the most anterior tooth in order to thread the dam deep enough through the contact points and retain it in place. I’d place a normal dam clamp on the most distal tooth then to keep the dam sheet gingivally placed and then put the dam frame on. OptiDam comes with a great mouth shaped plastic frame which I think is a lot less likely to cause optical injuries in your patients like the older style metal frames! 

Then I’d place the anatomically shaped sectional matrix band through the contact point and wedge it using the really nice flexible plastic Wedgewand. There is a specific set of forceps in the kit to allow proper placement of the band without deforming it. You’ll find the Wedgewand produces very tight adaptation of the band against the tooth because it is a stretchy yet firm material. But it still won’t push the band out towards the adjacent tooth to allow a good contact point to be produced. 

At this point I use rubber dam clamp forceps or the ones provided with the kit to apply the Composi-tight Soft Face 3D-ring. This is where the genius of this system comes in! What the clamp does is firstly drive down the rubber dam better and secondly the compresses the band interproximally as the 3D-Ring is released which pushes both teeth apart and pushes the band right out against the tooth. So when the restoration is finished and the 3D-Ring released the contact achieved will remain very tight, wide and deep. In my experience this is impossible with a straight Siqveland and wooden wedges even when holding out the most proximal part of composite because composite can’t be effectively compressed. Also the sectional matrix bands are not just straight they are curved anatomically in order to produce a larger bulbous contact area with less likelihood of food trapping. With a conventional matrix band if a tight contact is produced I find quite a bit of flash results and this is a total pain to try to remove after finishing the restoration. With the Composi-tight matrix system the band is compressed so tightly against the edges of the cavity that excess composite being pushed out isn’t an issue. 

These rings can also be used 2 at a time so that producing an MOD restoration is easier because sometimes removing a tight matrix can stimulate gingival haemorrhage from below the dam. 

Building up the composite 

Going back to the need to minimise contraction as above. I find it is best to build the restoration as follows: 

* I will etch both enamel and dentine together, aiming to place etch on the enamel before the dentine because it is necessary to etch the enamel for longer. I would say at least 30s for enamel and 15-20s for dentine. It is commonly known that dentine doesn’t need to be dried to the same extent as enamel. The enamel should be frosty but exclusively drying enamel to this degree is too hard. What I learnt to do is to dry both and then rehydrate the dentine slightly. I suspect this is the key to reducing that dreaded post-op sensitivity and since doing this I have anecdotally found fewer people returning with postoperative sensitivity. Dentine can be rehydrated using water or chlorhexidine on a microbrush and then gently air drying the dentine without affecting the enamel’s frostiness. I have to say I’ve never tried using chlorhexidine. 

* I would then usually use a good quality bonding agent like Optibond Solo Plus and gently air dry this from a decent distance (maybe 10cm) for about 20s just to evaporate off some of the solvent and then I would light cure. 

* Use flowable composite or heated composite. The idea here is to provide a wet, smooth surface with rounded angles ready for the next layer to bond to. The runny composite will ensure the entire cavity floor is bonded to. If using flowable then it is best not to allow this to reach the margins of the cavity as it is not as stable as normally filled hybrid composite because there is less filler content and is such this would be a weak point for the restoration. It is also a good idea to do this after the next stage below if using a flowable composite in the base. This is why I like heating composite, simply in a lab bag immersed in warm water for 10 minutes. This layer should be set for a good 30s. 

By the shrinkage formula written above it is then best in my opinion to consider building up the proximal surface and marginal ridge first in an enamel shade of composite. Why? Well this is done because this will only shrink to a minimal degree because there are fewer surfaces bonded and hence a lesser degree of contraction shrinkage. Once this has been built up it is then possible to treat the rest of the cavity as a class 1 composite. 

* I would build up the occlusal aspect in small 1-2mm incremental stages by trying to form the cusps but only going 1mm short of the cusp tips. This is best done in a dentine shade which is 2 shades darker generally than the enamel shade being used on the top surface layer. 

* At this point if you are going to do some occlusal staining it is best to do it here using a probe as a subsurface layer and then build up the remaining 1mm enamel layer on top. 

* I would then take off the 3D-Ring, wedges and dam and then think about checking the occlusion. Once this has been checked I would consider using a wooden wedge to push the teeth apart and then use a very fine composite finishing strip in order to remove any small amount of flash without removing the contact point. Occlusal anatomy should be carved in place and polishing carried out. 

* Composites wear resistance is decreased if there are fewer filler particles exposed at the polished composite surface. How I have learned to deal with this is by then re-etching the surfaces and bonding over the polished enamel composite layer with a fine layer of dentine bonding agent. This provides more resin at the surface and greater wear resistance. 

Large Class 2’s 

I don’t know what people think about the upper limit to the size of cavity they are likely to do directly. In my experience the bigger the greater the degree of sensivity at the margin and obviously the greater the risk of cusp fracture. In my head I have a rule that I’m now quite keen on sticking to with my patients. I think that if the width of the box at its widest point is much greater than a third of the width of the tooth or if there is less than 2mm width of any cusp left then I don’t like to do direct composites. In these circumstances I prefer doing indirect composite onlays (Belleglass). http://www.americanadental.com/html/belle_glass_.html 

Belleglass is a heat-and-presure processed indirect composite polymer. 

I am really keen on these at the moment. Once my cavity is prepared I onlay prep any undermined cusps with a hollow-ground chamfer margin and I place a layer of radiopaque glass ionomer as a lining not extending onto the cavity walls. I feel this dramatically reduces sensitivity during temporisation with Systemp Inlay. 

I then try-in the restoration and make any slight adjustments needed with the exception of occlusal adjustments because it is fragile until cemented in. I then isolate and etch (to remove salivary proteins) both the cavity and fitting surface of the restoration prior to washing, drying and then I cement in place with RelyX’s Unicem. Then I check and adjust the occlusion as needed. I am a really big fan of these at the moment. 

I’m interested to start a discussion on this topic and find out what other people do. I’ll make a video of my procedure for direct composites when I next do a good example of one.

I will upload a couple of cases to show the sectional matrix in use.

Here are the pictures from my first emax crown.

If you want to know a little about emax crowns then have a look at this video from Mark Oborn.

I confess myself to be a Mark Oborn Fan and you can read more about his lab on this blog.

I’ve put all the pictures of my case into a little video as I’m finding it an easier way to present a group of slides. However it’s hard to put all my comments on the slides so watch the video once, read the extra info below and if you need to watch again. Also here is a link to the high def version: emax crown

The patient was unhappy with the PFM crown and clinically I was pretty unhappy with the margins. The tooth had an adequate root filling. I offered the patient a private replacement. I reprepped and sent the photos with the impressions. It was the first time I’d used the lab (not SBO btw) so I wrote an introduction, described the case and the shade I also drew this on the lab ticket

Here is a quote from the email

“Please find attached a series of photos for the emax crown case I have sent to your lab.
They show the preop smile, ICP and open views. A view of the smile with a shade tab c2 and my prep pictures and temporary crowns which are for reference only, I’m not sure you will need them. I’ve sent you a few pictures in different positions with different flash positions to help show you the reflection patterns better.
As for the shade I think the tooth is c2 at the incisal edge but blends down into a a shade closer to c1 near the apex. It’s an unusual transition.

2 weeks later I fitted the crown.

Now if we critique the crown I think the fit was excellent around the margins the incisal level and shape is good. However I find the shade to be too monochrome. Where is my transition to C1 cervically. The patient was really happy with the crown though and it was a huge improvement. Also to be honest I couldn’t guarantee a new crown would be any better as single teeth can be hard to match and I coudn’t see what more information I could give the lab. So I fitted it and my patient was made up.

I’m a bit disappointed though. The lab is a pretty well know one in the north east and I paid for premium service about £120. I think they have just put shade c2 on this crown and I suspect I won’t use them again. It depends how they respond to my email critiquing the work.

Lets not just blame the lab though. What could I have done better?

Well you can see from the prep pictures that the cervical third of the labial service is just underprepared and I kick myself for not checking and adjusting this a little. With more space the technician might have had room to improve the aesthetics although emax does allow minimal reduction.

Also the gingiva at the apex is slightly receded after the temporary crown. This should drop as the soft tissues settle but I should have cut a negative ledge in the temporary to prevent this at fit.

So what are your thoughts?

Good, bad or average. Don’t get me wrong I’m pretty happy with the case overall and that crown should last for many years doing a far better job than it’s predecessor. I just hate relying on dental labs that don’t listen to me. I can’t see any evidence of a second shade in that crown and I wonder why. The problem is I just don’t know enough a bout making emax crowns to have an open discussion with the lab.

Next year I want to spend 1 day a week working in a dental lab as an apprentice. I want to get to know the team, learn the techniques, shadow and be able to do the lab work myself if I needed to. I’m excited to do this and I think it will prove a very wise investment in time. Think about all those expensive masters courses where you pay a fortune to learn how to do lab work. Wouldn’t it be wiser to work with a lab for free, just give your time and pay with cases you send?

You may ask why a lab would do this? and I guess the wrong ones wouldn’t. But I think some would think that this is a unique opportunity to really work with a dentist, get a good understanding and lets be honest have his business for the rest of his career.

I’m well up for it and I see know reason why you shouldn’t bang on some doors and try to get a similar opportunity. Time can be as much an investment as money and expensive courses are not always the key to further development. a business partnership might be though. Just a thought for you…

Hope everyone had a nice easter

All the best

Chris

This is just a quick video showing what happened next with the sectional matrix case

There are only 2 reasons for this post.

1) I wanted to work out how to embedd video content without youtube interferring

2) Dundee Dent asked to see the post ops and I feel like a real cheat if I don’t show them

As you can see the composite finish is nice but nothing special it’s a core build up so I’m pretty happy with it.

By removing the amalgam in 15 we get a unique opportunity to assess the emergence of the composite from the sectional matrix and I’m really happy with this one!

As we discussed last blog the 15 was non vital, I removed the amalgam without local anaesthetic after pulp testing and found both a very deep mesial box and a very necrotic pulp. Vast amounts of ledermix lining! The plan is to rct 15, core build and crown lengthen interproximally so I can crown. I’ll show the pictures as I get them.

I had a very open discussion with the patient about the 13 and we decided to monitor it at present. I think we both felt the risks of trying to improve the tooth outweighed the benefits while it was non symptomatic.

Anyway enjoy the vid, let me know if you like them. I think they are an easier way to present a group of photos than seperate photos. Some people have said the writing was too fast. Is it? I can slow it down if needed.

Any bloggers out there want to put independently hosted videos on their blogs then try Kaltura. It’s a brilliant little plug in!

Have a good weekend

Chris

Hi all,

I’ve been having  a naughty play with Picasa yesterday just messing with some of it’s functions after cropping, sorting and appraising this weeks photos.

I’ve put together a little Vid to hopefully better explain the anterior matrix technique I keep mentioning. Some people said they were struggling with it so hopefully this will help.

You can see it in high definition by clicking this link.

Anterior Composite matrix

Or see the compressed youtube version!

Let me know what you think of putting some stuff on video like this, was it useful?

All the best Chris

P.S. If your struggling to see the youtube version I apologise, I think they must sensor them all before they go public. Just click on the link instead it doesn’t take long to load!