to bevel or not

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believer88

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hi
Im trying compile the advantages of beveling composite restorations for my operative exam tomorrow :scared:.
i came up with two. i f you know more, pls add

1- more surface area for etching. this is of advantage to enamel that needs more etching
2- aesthetic reasons

on the other side no beveling means more conservative preparation. pls add to the list! thanx.

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hi
Im trying compile the advantages of beveling composite restorations for my operative exam tomorrow :scared:.
i came up with two. i f you know more, pls add

1- more surface area for etching. this is of advantage to enamel that needs more etching
2- aesthetic reasons

on the other side no beveling means more conservative preparation. pls add to the list! thanx.

Bevel a facial restoration for esthetics. Don't bevel a posterior restoration- blending is not a concern, and also the beveled area is the thinnest part of the restoration...in a posteiror area subject to chewing, that will be the first area of failure.

Of course what you're taught in school may be different, regarding posteriors. But you're right about your 2 reasons.
 
What he said....

You will want to bevel in non-stress bearing areas (i.e. areas that don't undergo occlusion) in order to expose more enamel rods for bonding. Bonding to enamel is 4x stronger than dentin. Also, make a nice long bevel on facial composites to hide the margin, reduce staining.

Hup
 
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How many reasons do you need to give? Those 2 sound like the best to me. Your instructor didn't list reasons for you to study?
 
Main reason for beveling is esthetics. Second reason is bonding.
 
How many reasons do you need to give? Those 2 sound like the best to me. Your instructor didn't list reasons for you to study?

he did. i thought maybe there are more? i just had oral surgery exam the day before and couldn't exactly find time to go thru all the notes. anyway, the q didnt come up in the exam lol
 
Sorry The Hammer but don't agree with you. Beveling in posterior surfaces is a no-no according to several professors including the ones that did private practice before. It's going to be worn after a while and then you won't have a tight seal.
Anyway, I guess it depends on your school.
 
-The Hammer.

I was gonna ask you about your "pre-dent" listing haha

Your logic makes sense to me, but we are also taught at Temple NOT to bevel in posteriors.
 
I bevel ALL my composite margins for four reasons:

-Better Esthetics/ blending
-Etch the ends rather than the sides of the enamel rods
-Less microleakage
-Stronger bond
 
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Composite preps get bevelled. Amalgam preps do not get bevelled, unless its associated unsupported enamel. Maybe the OP is confusing preps.
 
I really wonder what the rationale for not beveling is? Could you ask your instructors and post it here? But I will also say this, having been dental school faculty at one time, just because they teach not to bevel doesn't mean that it is a good technique.

I heard the non-bevelers' argument. And it did make some sort of sense 10 years ago when the material was not as good as it is now. Beveling increases the surface area of the final restoration, which increases wear and the likelihood of being under occlusal stress==> higher failure rate. As you know, in composite restoration, the smaller the better, so I decided to keep my bevels minimal in the occlusal.
 
I heard the non-bevelers' argument. And it did make some sort of sense 10 years ago when the material was not as good as it is now. Beveling increases the surface area of the final restoration, which increases wear and the likelihood of being under occlusal stress==> higher failure rate. As you know, in composite restoration, the smaller the better, so I decided to keep my bevels minimal in the occlusal.

We are taught to bevel with composite restorations with the exception where the preparation must extend below the CEJ thus the cavosurface margin is on cementum. In this case you do not make a bevel.
 
We are taught to bevel with composite restorations with the exception where the preparation must extend below the CEJ thus the cavosurface margin is on cementum. In this case you do not make a bevel.

In this case I don't use composite. If the patient insists or in the anterior region, I open sandwich with RMGIC.
 
This is exactly why you want to bevel in the posterior. If a bevel is properly done it won't fail due to mastication it will just wear down. No bevel and you can get marginal failure due to compression of the tooth from occlusion over time.

I don't agree with you at all. No bevels on posterior composites. The thin composite over the bevel will fracture under occlusal forces allowing leakage and eventual restoration failure. Bevels are indicated in non stress bearing areas to provide additional surface area of enamel for bonding and esthetics. I'll sometimes bevel the lingual surfaces of maxillary anterior teeth if needed for retention (i.e. Class IV) but you need to be aware of occlusal contacts on the lingual otherwise you can have the same problems as described above with the posterior restorations.
 
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OK lets see if you guys are really thinking about this.

The outermost edge of my posterior composite bevels (outlined in orange) are usually flowable composite. Why would doing this give my restorations a greater chance of success and prevent leakage.

img0209c.jpg

because it fills in the minor voids, and like you said it has a little more give to it?

Hammer, can you explain the chamfer part of your bevel in a little more detail, and the reasoning behind it?

At UTmemphis some professors tell us to bevel the posterior occlusal, while others tell us not to.
 
OK lets see if you guys are really thinking about this.

The outermost edge of my posterior composite bevels (outlined in orange) are usually flowable composite. Why would doing this give my restorations a greater chance of success and prevent leakage.

img0209c.jpg

Because flowable seals all potential spaces of microleakage (e.g. small fissures or bur mishaps leading into the restoration) and leaves little chance for substrate or bacteria to leak into the composite. Flowable has high wear, but like you said, it shouldn't all be in occlusal contact.

Hammer, we have been taught not to bevel posteriors (at least at my first year level, although another student above who I know is a senior at my school just said that they were told to bevel posteriors= may be due to huge faculty changes in restorative dept.) and your method does seem logically effective, but is there any evidence in the literature to support this? I know sometimes things sound good, and your experience with them seems to support the method, but it's hard to base your entire procedure methodology off of single case studies or individual opinions. Thanks.
 
Then they are wrong. Here is a part of a lecture that I recently gave to the UF dental faculty. The lecture was on incremental composite placement for posterior restorations. I've been doing them this way for 15 years so I've got a damn good follow up on them to see if they fail. They don't.

I used both photos of the procedure on a dentoform for illustrative purposes but I also included clinical photos in the lecture. Here are the photos of the preparation

First of course is clean out all decay and don't leave any unsupported enamel.
img0200gf.jpg


Then I put about a .5mm bevel at the junction of the occlusal surface and the interior of the preparation
img0205fu.jpg


I use a 30 micron football diamond to do this in the mouth
img0133kg.jpg


Then I place a very thin chamfer about 1-1.5mm up on the occlusal surface.
img0209c.jpg


I do this with a fat and thin flame shaped 30 micron diamond in the mouth.
img0135fj.jpg


img0139y.jpg


Oh and if you haven't figured it out yet the "pre-dent" thing is my idea of a joke. I've been in private practice for 17 years and I've taught at a dental school.
Thanks you for the post.

 
Because flowable seals all potential spaces of microleakage (e.g. small fissures or bur mishaps leading into the restoration) and leaves little chance for substrate or bacteria to leak into the composite. Flowable has high wear, but like you said, it shouldn't all be in occlusal contact.

Hammer, we have been taught not to bevel posteriors (at least at my first year level, although another student above who I know is a senior at my school just said that they were told to bevel posteriors= may be due to huge faculty changes in restorative dept.) and your method does seem logically effective, but is there any evidence in the literature to support this? I know sometimes things sound good, and your experience with them seems to support the method, but it's hard to base your entire procedure methodology off of single case studies or individual opinions. Thanks.

#
 
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because it fills in the minor voids, and like you said it has a little more give to it?

Hammer, can you explain the chamfer part of your bevel in a little more detail, and the reasoning behind it?

At UTmemphis some professors tell us to bevel the posterior occlusal, while others tell us not to.
@
 
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The Hammer,

I have never heard or read of flowable "up and out of the prep a bit". I usually do my best to keep it away from the margins. It just cannot take normal occlusal forces, let alone parafunction. I am not ready for this yet! Simply because the connector between two materials is usually weaker than both, why do you want to use a weak connector?

And by the way, although I share your opinion about occlusal bevel in posterior composites, I wouldn't call what you posted "evidence".

Thanks for the discussion and the pictures.
 

If you're going to give us literature to prove you need to bevel, how about reading what you've linked us to first?

Bevelling is a possibility for interproximally involved class II occlusal lesions, but not recommended for occlusal/class I lesions.

Let's take a little look at these shall we?

http://www.oralhealthjournal.com/issues/story.aspx?aid=1000113494

"The occlusal cavo-surface margins of the parallel axial walls along the isthmus and dovetail of amalgam preparations in cuspated posterior teeth usually exhibit an obtuse cavo-surface angle and do not require additional beveling for good bonding (Fig. 26)."

http://www.ispub.com/journal/the_internet_journal_of_dental_science/volume_7_number_2_20/article/clinical-evaluation-of-different-posterior-composite-restorative-materials-in-class-i-and-class-ii-restorations-an-in-vivo-study.html

"A "butt-joint," clean-cut non-beveled preparation is preferred to a beveled cavosurface outline. A beveled preparation results in a thin marginal fin of composite material which could fracture, leaving a ledge –type defect in the marginal region."


Isenberg BP, Leinfelder KF, Efficacy of beveling posterior composite resin preparations. J Esthet Dent 1990 May-Jun;2(3):70-350

"Beveling the occlusal cavosurface margin had no clinically significant effect on the performance of posterior composite resins. Specifically, no clinically significant difference could be detected ..........etc. On the basis of these results, then, it is suggested that beveling of the occlusal cavosurface angle should not be carried out"

Direct posterior composites - A practical guide
Dental Update 2009;36:71-95 - Louis Mackenzie (Lecturer at Birmingham Dental School, UK)


"Bevelling is not recommended occlusally, as this may result in a thin margin of composite, which could be prone to fracture under occlusal load."

I have disregarded dentalcomposites.com as I don't accept websites as valid literature that have not been peer reviewed. Was that other document actually submitted for peer review and published in a highly regarded journal?

Come back when you have higher quality evidence please. Last time I checked, Universities, at least not in England, didn't count websites as valid references either.
 
I too did not seem to think that these articles conclusively recommended class 1 beveling on posteriors. However, I haven't really searched the literature more comprehensively myself to see if any do recommend that.
 
Enjoy debating the merits of bevels. I think I've had enough trying to help for today
 
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...show me evidence that shows you SHOULD not bevel...

If you read my reply, they ARE literature that proves NOT to bevel. I'm simply quoting the evidence. What else would you like me to show?

Thanks for the debate too! Although I feel that everyones opinions are always valid, and that you shouldn't have edited your posts - they provide good points to debate.
 
If you read my reply, they ARE literature that proves NOT to bevel. I'm simply quoting the evidence. What else would you like me to show?

Thanks for the debate too! Although I feel that everyones opinions are always valid, and that you shouldn't have edited your posts - they provide good points to debate.

Agreed, dentistry is not about absolutes. If his technique has been working for years for him, apparently he is doing something right. It is about making the procedure work for the patient. I'm just trying to find out different methods as a lowly dental student that will work best for me in practice.
 
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