Lithium Disilicate Ceramics, Part 2: Ceramic Onlay Preparation

[@RabeaAbid]

its really enjoying to watch this amazing videos, all respect for FULLY explanation + excellent work 👍🏻

[@genesispaxton4167]

Dunno if anyone cares but if you are stoned like me during the covid times you can watch pretty much all the new movies and series on InstaFlixxer. Been binge watching with my brother lately xD

[@kennethlian3585]

@Genesis Paxton Definitely, I've been watching on InstaFlixxer for since november myself :D

[@loveless_gen]

great video! it makes me think about how much tissue has to be removed to treat a decayed tooth, besides the tissue already lost to caries. It's always better to prevent decay, because even the simple fillings lead to healthy tissue loss.

[@StevensonDentalSolutions]

Yep!

[@hasnashahid1128]

You are a great teacher. Thank you

[@StevensonDentalSolutions]

Bless you

[@yusufchaudi2062]

Fantastic work Dr. Great video as always, incredibly informative, and fantastic technical skill that I can only wish to one day emulate. I have a question if you wouldn't mind answering In regards to indications for an onlay. Would you say that you have certain criteria/guidelines that you would asses a tooth by, to evaluate if an onlay is the best option as opposed to a direct restoration? Thank you in advance

[@StevensonDentalSolutions]

Such a tough question! If the occlusal surface needs restoration which will include cusps, or when the isthmus is wider than 3 mm for molars, or when there are symptomatic cracks (use a tooth slooth to evaluate), or when a crack extends gingival with dark stain, or when the tooth is structurally compromised but has good enamel and dentin on the facial and lingual. Ultimately it is a clinical judgement call. The decision to place a direct, or an inlay, or an onlay or even a full crown is not always clear and the same situation would likely be treated differently depending on the dentists' philosophiy, skills set and prior training. Best to you!

[@aminfereshtehhoosh4570]

Hi Tnx for ur sharing This is actually an overlay prep,isnt that? And what would u do about opposite tooth wear due to this tooth ceramic restoration? Tnx again

[@alejandrasosa9441]

So its better to always do a shoulder then on onlays preparations than no shoulder approach? It should only be performed on the functional cusps

[@StevensonDentalSolutions]

GREAT QUESTION! A Master's Thesis I mentored at UCLA clearly showed that shoulders on functional cusps were better than shoulder-less preps in terms of durability. I also believe that the A, B, and C planes preserve the anatomy of the tooth and the shoulder simply increases the thickness of the ceramic in a critical area. The flat top, non-anatomical approach may leave the ceramic weak in these areas, and the flat top prep is more aggressive with the tooth structure as a whole. Thank you for watching, Dr. S

[@mansoorkhan8272]

great video dr ... i have a question a few texts say that the ceramic onlays should not encircle cusps and that there should be no shoulder preps like the one you showed here , only beveling of cusps , whats the scientific difference between the two approaches?

[@StevensonDentalSolutions]

Back in the feldspathic days we saw that the wrapping of cusps with shoulders led to some material fractures and opted for flat tops as you mention. With the significantly stronger lithium disilicate materials, this is no longer the case. A research paper I co-authored in 2018 looked at the different designs and we found that shoulders are better for ultimate tooth-restoration strength. The paper is at the publisher...Capping cusps works incredibly well with LD and likely leads to a stronger final restoration/tooth, and if performed well may preserve more tooth structure as the flat top design on the functional cusp reduces more tooth structure due to the lack of cusp incline preservation. Thank you Doc!

[@mansoorkhan8272]

@@StevensonDentalSolutions thanx for the informative reply dr stevenson , i am adopting your style of prep from now on in my practice

[@Mcknockout777]

@@StevensonDentalSolutions HI Dr Stevenson, whats the title of your publication? Would love to read it, thanks

[@DentalBeyond101]

Great video but what is A plane, B plane, C plane?

[@StevensonDentalSolutions]

It's explained in the full crown video. A plane is the functional cusp bevel, and the B and C planes are the typical "V" shape we perform on every posterior crown prep.

[@twindentists123]

HI doctor - amazing work as always. Is the prep carried out using an electric speed increasing handpiece ?

[@StevensonDentalSolutions]

yes - my preference - slow to 500-2000 for refinement after prepping at 100-200K

[@mohammadkhalil3265]

Thanks to sharing I have 2 questions: 1-why not prep functional cusps like non -functional? 2-why do shoulder finishing line? We can do the design like buccal cusps just reduce the hight ? Regard You not talking about IDS after prep ?

[@StevensonDentalSolutions]

Hi Doc - great questions: 1. Typically only functional cusps require shoulders and cusp capping in order to provide better resistance form to the restoration and tooth. There are times when a shoulder (cusp capping) on the non-functional cusp would be necessary (cross bites, heavy occlusion, perhaps end treated teeth, etc) but the "shoe" design (as in the vid) on the non-functional cusps has been the standard of fixed prosthodontics. 2. The flattening of the lingual (functional cusps) without a shoulder requires a little more tooth removal in reality - strange perhaps, but it does, and in a Master's Thesis study at UCLA performed by my grad student, Dr. Shahed Al-Khalifa found that the shoulder design was consistently stronger than the "V" prep or "flat" functional cusp design.

[@StevensonDentalSolutions]

I have an inlay yet to perform and then yes, we will discuss all options: Immediate (Magne), Delayed (McLaren), Simultaneous (UCLA) and Pre-cementation (Manufacturers) - there are plusses and minuses to each technique.

[@mohammadkhalil3265]

Stevenson Dental Solutions thank you so much dr to your informations Hope to still in these videos Regard

[@alaaahmedmokhtarahmedsaleh9715]

Great job as always ....I have a question please ....onlay preparation is indicated with sever attrition Pt due to bruxism habit ??

[@StevensonDentalSolutions]

Complicated answer...essentially if the wear is due to nocturnal bruxism, and the patient wears an orthotic, then yes, onlays are great. IF the wear occurs during the daytime, diurnal bruxism, then it's a bit less predictable, and either gold or zirconia will be more durable than lithium disilicate. If the wear is due to a past grinding habit that has stopped, then you may treat as normal. Is the wear active? This is an important concern.

[@angelafrantz1909]

Wonderful video! Any thoughts on how to tell if wear is active?

[@titaEm94]

Why reduce teeth with no water? Won't it dehydrate or burn the tooth??

[@StevensonDentalSolutions]

Use water clinically, except when finishing margins. What causes more heat to the pulp: a sharp bur with a light touch or a prophy cup? Answer: a prophy cup - good science supports this.

[@richadembla8458]

Hello dr I have a question about cementation, which cement would be the best for onlay??

[@StevensonDentalSolutions]

Any posterior dual cure resin cement will be good.

[@ttsuter87]

How much do these cost per tooth. I would need it performed on all my first and second molars. Such horrible sensitivity has debilitated my life. Can’t eat anything hard or anything requiring substantial chewing. I hate eating for this reason.

[@StevensonDentalSolutions]

So sorry to learn of this. The fees for onlays range dramatically depending on the location and practice philosophy. Typically in the So Cal Area, fees would be anywhere from $1400-3500 or more. We have a patient based study club and charge less than this. Feel free to reach out to our practice through stevensondetnalsolutions.com

[@mohamedfattah411]

thanks Dr. for sharing , i would like to ask what (a plan & C plan ) stands for , & i ould like to ask what is the difference between overlay prepartion in this case??

[@StevensonDentalSolutions]

A plane = functional cusp bevel, C plane = non-functional incline reduction. Only = either a show or a cap. Watch more videos from me on this...

[@radujko]

what is the B plane? thanks@@StevensonDentalSolutions

[@cindiyaj2318]

Hi Dr Stevenson, do you always make mesial and distal boxes for full cuspal coverage onlays? Would you do so with a root filled molar with a small class I composite in the access cavity

[@StevensonDentalSolutions]

Not always - I will perform occlusal onlays without boxes IF I can obtain a finishable margin on the mesial and distal - this is tough as it must not enter the contact area.

[@nooransari4831]

Your vedio is very helpful. Very much motivation to do work with high degree of perfection. Thanks Dr.

[@StevensonDentalSolutions]

Thank you Doc!

[@qqwerttrewqq]

Great job as always !!! What do you think about composite indirect restorations ? Would you change anything in your preparation if you were preparing it for composite indirect restoration ?

[@dentalmitra7864]

Thanks doc, for promt reply! I am not quite clear yet , so pardon me for continuing with my query and taking more of your precious time. Is it the extent of caries on the facial and lingual surfaces of the teeth you're implying? Is there a general guideline for the distance of the finish line from the cusps . I am unable to relate cusp morphology with the curve of the finish line. So if you could throw some light on it in a way I could grasp it . Thanks again.

[@StevensonDentalSolutions]

Hi - no worries. Onlays require the reduction of the occlusal surface just like a full crown - the major difference is that Onlays don't include any more of the facial or lingual surfaces, unless caries (note the lingual grove extension) dictates this. Like a full crown, Onlays follow the cusp morphology during reduction, rather than just a flat top prep, hence the facial outline you see in the video - it follows the shapes of the cusps, rather than creating a straight finish line as viewed from the facial. The lingual finish line is also like a sine wave - following the cusp shapes, and only extending beyond this gingivally if a defect or caries dictates this modification. In the video, as viewed from the lingual, the finish line dips to include the caries in the lingual fissure area. There are an infinite number of outline forms with Onlays (which makes them so interesting and fun) allowing the dentist to be creative and conservative at the same time.

[@الصقرالجارح-ت1ش]

Thank you Dr . But l have question what's the of c plan and B plan? meaning

[@StevensonDentalSolutions]

Hi Doc: I explain this in the FGC video, but it is the names given to the 3 occlusal planes: facial (c plane) lingual (b plane) and the functional cusp bevel (a plane) as viewed from the proximal. Thank you for the question!

[@الصقرالجارح-ت1ش]

Thank you doctor

[@StevensonDentalSolutions]

My pleasure!@@الصقرالجارح-ت1ش

[@dr.hasannammoura3824]

Hi dear Dr. Stevenson, what an amazing and incredible vids you produced. I have a question if you wouldn't mind answering, the prisms directions on buccal side differ from palatel side, will that affect the prep on buccal side like to make bevel on it?

[@StevensonDentalSolutions]

Thank you, Doctor. You are correct - two important points I'd like to make, remove loose enamel prisms (slight bevel) on the buccal side to avoid chipping during the temp phase and don't bevel too much as this will thin the ceramic and complicate manufacture and potentially weaken the ceramic.

[@abdulqaderalbadry6946]

hi doctor... I'm a big fan of you and your videos... i was wondering why you didn't make a shoulder or chamfer on the facial?

[@StevensonDentalSolutions]

Hi Doc, typically non-functional cusps don’t require a shoulder they are “shoed” rather than “capped” because they are not under the same stresses as the functional cusps. I will cap the non-functional only when necessary due to structural compromises or defects/caries. Best, Dr. S

[@abdulqaderalbadry6946]

@@StevensonDentalSolutions Thanks doctor for your fast and informative replies. i hope the best for you

[@tvalue4618]

Is there a burr smaller than one millimeter?

[@StevensonDentalSolutions]

Yes 0 the 846-012 has a 0.6 mm tip.

[@tvalue4618]

Also can an onlay be made from old impressions I have of my teeth???

[@Ahuromazda]

One question Dr. The caries was on MO surgace why did you also prep the distal surface? When prepping for onlay do u have to create a box on M and D sides or is it just in this case?

[@StevensonDentalSolutions]

Excellent Comment and Question! When you need to replace the occlusal surface due to wear (exposed dentin), you need to decide on the proximal finish lines. To keep the finish lines occlusal to the proximal contact zone is rarely an option due to the need to keep the restoration margin free from the proximal contact. If the morphology of the tooth and the current situation allows, you can occasionally do this - however, it is not a common finding, hence, I drop the box form to extend past the contact areas. On a terminal tooth, (a second molar with no third molar, for example) the situation is entirely different and the distal finish line may be kept on the distal occlusal portion of the marginal ridge.

[@KSuperstar98]

Hello! I'm new to onlays and ceramics. Can emax bond to composite?

[@StevensonDentalSolutions]

Yes, for sure, using air abrasion on the composite build-up/block-out), then following the protocols described in the videos - its a pseudo-micromechanical bond with chemical links to the unpolymerized monomers in the original composite

[@bannatrinadarao3789]

Great job and some comments are i observed and i would like to say it's easy if u know the morphology and histology of tooth and should have good clinical background u can go head without any fear

[@StevensonDentalSolutions]

So true!

[@mikechao9898]

Do you need to bevel the gingival floor?

[@StevensonDentalSolutions]

Not for ceramic, only for gold - Thank you

[@acash93]

Merry Christmas! Great video. "Far from perfect" is quite an understatement :)

[@StevensonDentalSolutions]

Merry Christmas Doc! Thank you for your kindness.

[@pikaraichu6516]

I love you, thanks for teaching us.

[@StevensonDentalSolutions]

Thank you!

[@haider_kadhim]

Hi , thanks for this great video, i have Questions if u don’t mind , these artificial tooth u prepared from which store u got ? Can put. A link for buy it or how i can make one like it

[@StevensonDentalSolutions]

These are human teeth in this video.

[@sandrosanna3364]

I still don't understand that shoulder on the functional cusp. I don't think it will provide more resistance

[@StevensonDentalSolutions]

If you understand the purpose of the functional cusp bevel in gold crown and onlay preparations, it will be more clear. Essentially the ceramic if left without a shoulder, will be infinitely thin when the tooth is in occlusion. The shoulder provides the necessary bulk to this area. Alternatively, if you prepped the tooth flat, the shoulder would not be necessary as bulk would be obtained via the over-preparation, however, Flat preps reduce more tooth structure. Another aspect of the shoulder is that it places a vertical wall onto the functional cusp which is parallel to the other internal walls and thereby puts the cement under compression rather than shear forces. Even resin cements benefit from compressive vs shear stresses.

[@sandrosanna3364]

@@StevensonDentalSolutions ok I understand the purpose. thanks I have an other question. If it were a composite/resin overlay what thickness would have been sufficient for the axial preparation of the functional cusp? oh and an other question: what''s the V prep? can you show me any example I can find on the web?

[@underviv64]

this is way more damaging and time consuming Thant the V prep tho so argument is flawed

[@StevensonDentalSolutions]

You have much to learn about occlusion. It is about the forces generated on the excursive pathways. The V prep fails to meet these requirements and the literature is replete with evidence. Perhaps you could join one of our courses to understand this better...

[@underviv64]

@@StevensonDentalSolutions I’ve been told by one of the creators of the vprep and the Cerec rebuild He’s also backed up with a lot of studies that proves his designs correct and science based

[@naba8911]

It's so beautiful to watch, thank you Doctor!

[@StevensonDentalSolutions]

Thank you Doctor!

[@StevensonDentalSolutions]

GI = glass ionomer

[@reloadwrecks]

I am getting this done Monday. Really nervous and scared. Any advice? My left molar is chipped but no pain and no nerve exposure yet. Will I receive pain meds after and if so what? I am a big baby when it comes to tooth pain

[@StevensonDentalSolutions]

Typically this is not a painful procedure - you'll feel nothing while the tooth is being worked on and a good temporary will seal the tooth and provide you with a comfortable recovery. At most an Advil or Tylenol afterwards will do the trick. Best wishes!

[@fahadalsweleh6542]

Thanks Do we need to open proximal contact with onlay preparation?

[@StevensonDentalSolutions]

In most cases, yes. Leaving a margin in the contact area leads to numerous lab and procedural challenges including poor margin adaptation, difficult cement removal, inability to finish and polish, residual caries, contour difficulties, etc.

[@fahadalsweleh6542]

@@StevensonDentalSolutions Thanks But some teeth need to cut more gingivaly to open the contact which is aggressive preparation. Is there case report article with or without open the contact demonstrating complications after follow-up?

[@jormafer1390]

What’s the name of the instrument used for measure the millimeters?

[@StevensonDentalSolutions]

RGS 1-2 and RGS 3-4 check out stevensondentalsolutions.com

[@FL-gg4dq]

Is there a book you recommend for onlay inlay designs?

[@StevensonDentalSolutions]

by Stefano Bottacchiari

[@tvalue4618]

This actually makes me scared of getting an onlay, so much drilling 😩I can tell this is not for an unexperienced dentist

[@StevensonDentalSolutions]

Yes, I feel the same way - it's not easy being a patient!

[@tvalue4618]

@@StevensonDentalSolutions is this something most dentist do or mostly prosthodontist? I can’t seem to get any reviews for on onlay work from patients

[@dentalmitra7864]

Also doc, what dictates the placement of the external finish line ? It looks variedly undulating and not a constant curve . What is the reason ?

[@StevensonDentalSolutions]

Yea - caries and defects in the enamel, and then the cusp shapes. Follow the morphology...All the best!

[@FL-gg4dq]

Can you do this with zirconia? Retention is my worry

[@StevensonDentalSolutions]

Not the best for retention, but some are bonding zirconia chemically with good success. (See M. Blatz APC technique)

[@Ahuromazda]

Do you created that shelf on both lingual and buccal sides?

[@StevensonDentalSolutions]

Inly the functional cusp side: the lingual

[@DentalLens]

What is the difference between onlay and overlay?

[@StevensonDentalSolutions]

In the US, the proper term is Onlay. Essentially any indirect restoration which covers one or more cusps either through shoeing or through capping. In the textbook chapter that I co-authored on Indirect Gold Restorations for Summitt’s Operative Dentistry we never mention the word “overlay.”

[@ibrahimabulilah5260]

I am really thankful for this great presentation 😀😀.. but if i wanna place a temporary .. who can i ?

[@StevensonDentalSolutions]

Use the DuraSeal (Reliance Dental) product of use TelioCS (Ivoclar) direct material - works great and fast!

[@dr.avinashksajnani7930]

@hi doc , love your work . How do you choose between butt joint , bevel or shoulder margins on the cusps ? Thank you

[@StevensonDentalSolutions]

Usually use shoulders on the functional cusps and butt joints on the non-functional - these were tested at UCLA in a study I did and found to be the most predictable for strength. I will occasionally add a shoulder on the non-functional when the cusps are weak or after an RCT.

[@dr.avinashksajnani7930]

Stevenson Dental Solutions thank you :) , please keep the knowledge flowing ! Much love from Bangkok, Thailand .

[@HS-mg7ie]

why not Inlay? Is Cusp Capping essential?

[@StevensonDentalSolutions]

The cusp tips have exposed dentin and an inlay will not protect them. I believe that when faced with a worn tooth, we must design a restoration that not only removes the biological destruction (Caries) but also other aspects relating to structure and durability. The inlay option would address one aspect but not the others..

[@Channel_976]

Thanks alot doctor for sharing .. What does the overlay, crownlay, and occlusal veneers look like ??

[@StevensonDentalSolutions]

Great questions! I will make a vid in the future than demos the crowlay, vonlay, overlay...They are essentially all variations to restore the occlusal surface for various indications. Best, Dr. S

[@angelworld552]

What is difference in this and overlay

[@StevensonDentalSolutions]

Overlay is a variation of onlay - it's just nomenclature variation. Shillingburg never referred to these as overlays - only onlays. Some school's have adopted the term "overlay" to describe a finish line that includes the lingual or facial surface vs an onlay which stops at the line angle between the occlusal and lingual or facial. Confusing and very typical of dentistry to use various terms with much confusion.

[@nhlsens3880]

Great videos! I was wondering how come you dont create the axial reduction on the buccal surface as you do with the palatal surface?

[@StevensonDentalSolutions]

It's a non-functional cusp. Occasionally we would create a shoulder on the non-functional cusp when strength is an issue - like endo treated teeth or very thin walls.

[@nhlsens3880]

@@StevensonDentalSolutions Ok thanks. I see that generally people out there do not create a shoulder on the buccal or lingual surfaces for their onlays, but this makes sense. I thought this might be due to ease of preparation and ease of scanning... Do you ever find that there is an issue with the digital scanners capturing MODBL onlays where there is a shoulder on both the buccal and lingual surfaces?

[@Aries-Parish]

Thank you so much for the video so usefull

[@StevensonDentalSolutions]

Great! Thank you for your comment.

[@govarismael619]

Good job 👏

[@nada-jy8uh]

❤❤❤

[@StevensonDentalSolutions]

Thank you!

[@nooransari4831]

Thanks Dr . Please upload vedio on post endodontics restoration

[@StevensonDentalSolutions]

Yes it is in the queue. Thank you.

[@nooransari4831]

Thanks waiting for it

[@TarekHamadadawoud]

Why to reduce all the cusps?

[@StevensonDentalSolutions]

No need in every case - this was an example of a full onlay. Can leave cusps un prepped if they are strpng

[@yazansinan931]

Dr are you using high torque angled handpiece ?

[@StevensonDentalSolutions]

For the videos I use standard air turbine high and low speeds, but in the clinic I use high torque electric.

[@yazansinan931]

Stevenson Dental Solutions thanks

[@StevensonDentalSolutions]

@@yazansinan931 Thank you!

[@amberssable]

Hi! Could You explain planes?

[@StevensonDentalSolutions]

These are the angles that one must orient the bur in order to follow the opposing inclines, approximately 30-35 degrees. The A-plane is the functional cusp bevel.

[@amberssable]

@@StevensonDentalSolutions Thank You for the answer! And for Your videos as well, not many practictioners share freely their knowledge! Many of us learn a lot from You!.

[@aamin6933]

Thanks Dr for another great tutorial. If the functional wall is very thin, how is it possible to create a shoulder? Would a flat preparation be advised in these thin walls?

[@StevensonDentalSolutions]

Yes, flat would be good, and that could then be made into a shoulder IF necessary.

[@aamin6933]

Thank you

[@StevensonDentalSolutions]

@@aamin6933 My pleasure Doc!

[@francodallorso]

why are u destroying the health tissue???? the focus needs to be on the unhealthy part of the tooth

[@dentalmitra7864]

Great video doc! So enlightening. Feel more confident now to approach the conservative partial coverage option of an onlay , that I thus far have not ventured doing . Hope your following videos help boost me up to finally do it on a patient!! I share the views of Mr .Yusuf both his compliments to your video presentation as well as his query . It would be kind of you to let us know . Thanks doc for your upload .

[@StevensonDentalSolutions]

Nice! Hope you try these - they are challenging but very rewarding when they go well. Yes, thank you for sharing Rupa! Best, Dr. S

[@ralphboutros4416]

Hello ! Loved the video ! But I didn't really quite understand why the boxes on the distal and mesial.. ? Thanks again!

[@StevensonDentalSolutions]

It had caries on the mesial and a crack and caries on the distal.

[@suizidschlumpf2]

the fk you doing? you take away the whole tooth. you could have used like 3 more composite fillings until the tooth looks like this in 30 years.

[@Makers12Video]

What are you saying ?

[@fgrep15]

Lol, first of all, this is being done on extracted teeth on a model to show people how to do the procedure. Second of all you have no clue what you are talking about.