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Julian Chen
Julian Chen, Dentist
Category: Dental
Satisfied Customers: 568
Experience:  Practicing General Dentist since 2002
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Is there any way at all to lighten/whiten porcelain crowns?

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Hi. Is there any way at all to lighten/whiten porcelain crowns? Also, have been impressed with the idea of dentistry (major work) in Puerto Vallarta, Mexico - costs are a fraction of US, and dentists seem very professional and up to date. Thoughts on that? Also, if a person has major work done, which will change appearance and smile, how know ahead of time how aesthetics will come out? Like hiring an artist - how know until it's done?
There is no way to whiten/lighten existing porcelain crowns. There are a few people who are advocating placing new veneers on existing crowns. This works in the lab, but does not work when applied in real life situation. The bonding cement is not strong enough to hold the veneer bonded to the existing porcelain crown. And since the cost will be just about the same, you're better off replacing the crowns instead.

As far as traveling abroad for major dental work... I don't have a lot of comments on that. I can only hope that the dentist received sufficient training and the lab/material that he/she uses is up to standards. I believe there are some capable individuals outside of the States capable of doing fantastic dental work. I just don't know where to find one and whether you'd have any legal recourse should something awful happen.

The same as interviewing for a dentist here in the States, you can ask the dentist to provide you with a portfolio of their work. Models, casts, pictures of cases they've done. (Unfortunately, however, there are also pre-made portfolios that are sold and the dentist could simply pawn those off as their own work and you wouldn't know any better.)

Sadly, it's truly a buyer's beware situation.


Jul***** *****, DDS
Customer: replied 7 years ago.


Thanks. I appreciate your helpful info.

I wonder if you could give me your thoughts on the treatment options, if I described them. Mostly your take on whether any of what's proposed are bad techniques, or not durable, or whatever. I think I have found a great dentist, and what he's proposed makes sense, but I would feel much better if I could get some objective comments. I know you can't judge appropriate treatments without examining my teeth, but I'm sure you could tell me if his proposed treatment sounds like good dentistry. I have been to a number of dentists, and they all come up with very different treatment plans.

I'm happy with your answer above, and happy to pay. If I click accept, will that pay you and still allow you to let me know if I could follow up? I'm not too sure how this works.


Wayne Perham


You will be able to continue to post here with follow-ups questions after you've clicked Accept and I can do my best to answer those questions/concerns when I can.

I can certainly give you my opinion on the proposed treatment plan(s) but as you already noted, without knowing the current status of your teeth, the health of your periodontium (the supporting gums and bones), I won't necessarily be able to offer you much help. The dentist could be proposing to replace all your current crowns and restorations but if you have undiagnosed and/or uncontrolled gum disease, this may not be the best thing to do as some of your teeth may be in danger of falling out sooner than later. That's just one example of me not being able to provide you with the best answers that pertain to your particular case.


Jul***** *****, DDS
Julian Chen and other Dental Specialists are ready to help you
Customer: replied 7 years ago.

thanks. gums ok. bone ok they say 70%. proposed: pulling two teeth that have really deep decay, though no pain so far / root canal and crown on one tooth / veneers (porcelain or polymer ceramic, my choice (?) on 4 teeth 4,5,12, and 13 to reshape the upper arch (those teeth are too far inward), four front crowns replaced with porcelain on zircon crowns, "reobturation of old silver fillings on upper posterior teeth", a few composite resinn fillings, and "onlays" on lower osterior teeth to reposition occlusion.

I had never heard of onlays - are they a quality treatment?

So, I understand you're not in a position to know if this is appropriate, but I would ask - are these all legitimate, good quality procedures and materials?

And, also, do most dentists provide photos somehow of the expected results before any work is done, since this will supposedly improve appearance and smile greatly, or is it just hoping that the aesthetic result looks great?


wayne perham

ps what happens now - do I pay you again, or ?

The 2 teeth that have deep decay and treatment planned for extractions... are they your wisdom teeth? If not, do you know whether you'll miss having them for functioning (chewing/biting)? Ideally, if the teeth are restorable (especially if they are molars), and the surrounding gums/bone support is there, you should go through with the root canal treatment and then place crowns on them. Aside from providing cosmetic/aesthetic results, as dentists, we should also focus on trying to maintain your existing teeth as best as we can and extraction shouldn't be so quickly performed. (However, if the teeth were in terrible shape and you had preferred to extract and place dental implants, then that's a different and often viable strategy.)

The veneers on #4, 5, 12 & 13 (the "premolars/bicuspids")... I would advise you to be weary. They can certainly be performed as I have personally seen many done. I've also had the opportunity to replace a number of them performed by previous dentists. The veneers are held on simply by some composite luting agent. Lack of a better word, it's some form of strong super glue. But if you were to bite down on something hard enough, at the wrong angle, you're liable to chip/fracture the veneers and/or completely displace them. So in short, you can have the procedure performed and it will look great. But expect a certain level of fragility and that they may need to be replaced somewhat frequently.

I'm not keen on the "reobturation of old silver fillings on upper posterior teeth." If your current silver fillings are in good shape (granted they may be oxidized and dark in color), but if the margins are intact, then the fillings can remain serviceable for many years. I've seen silver fillings last over 50 years and still going strong. The point here is, unless the fillings are already failing, it is often better to leave well enough alone. Because as we go in to remove the filling, we have to make the preparation wider and deeper. And considering we're replacing a metallic filling (which has been fine, or I'm assuming never bothered you) with a composite/plastic filling... one would wonder how durable the replacement filling would be, especially if the size of the filling is fairly large.

I'm also curious as to why you need "onlays" on the lower posterior teeth. Would this be for all lower posterior teeth? Likely 8 teeth: numbers 18, 19, 20, 21 & 28, 29, 30, 31. If not, then the dentist would not have "repositioned" your occlusion. The final bite needs to be equilibrated, balanced. Unless your bite has collapsed significantly and that you want to open up your bite (perhaps to make room for your proposed upper anterior crowns), else one should not mess with the existing bite. Because if not done correctly, this can actually lead to the development of severe TMJ dysfunction/pain and although you may cosmetically fix one aspect of your mouth, you could essentially create a significantly greater problem when the TMJ do not respond well to the sudden change in bite height.

That say, an onlay is a legitimate way to restore teeth assuming the conditions/requirements are met to ensure its durability and longevity.

I cannot comment on the quality of the materials that will be used. Even here in the States, if a dentist chooses a cheap and lousy lab for their work, then the workmanship as well as the quality of the material would be suspect. But at least here in the States, there is potential for legal recourse, so that hopefully the dentist and the lab won't be as daring as to compromising the quality of their work.

Outside of the US, I cannot comment. Personally, I would think that some of these medical and dental providers have positioned themselves as "vacation services," and they realize that some of their clients fly great distances to come and see them. They may or may not care whether their work falls apart once the patients get home because chances are, they won't fly back and confront them. On the same token, these dentists may want additional referrals so you would think it'd be in their best interest to provide the best materials they can to generate future referral income.

Most dentist will be able to provide a portfolio of the work they've done, especially dentists who thrive on performing full-mouth reconstruction cases (such as ones that you're considering). This can give a sense of what it would look like, but again, it does nothing to show whether the new restorations are balanced and/or will function well. And ultimately, every mouth is different so what looks great for the guy/gal in the photo, may not look the same for someone else.

As for paying me again, it is solely up to your discretion. You get to decide if my response is worth the additional payment. And if it is, whether it's worth any bonuses.


Jul***** *****, DDS
Customer: replied 7 years ago.

thanks very much. I should have mentioned that, first, my wisdom teeth have never erupted, so that's four teeth that are not part of any treatment plan. The onlays, as I understand it, will restore part or all of the height of the lower teeth so that the bite or whatever it's called - the way the teeth come together - is more natural, as it is currently very unnatural - requires the jaw to go way back and way up for the teeth to meet. Does that explain the onlays?

Sorry, as to the teeth that have deep decay and recommended to be extracted, I forgot that that was the recent opinion of a different clinic, not the dentist whose treatment plan I'm describing for everything else. so, the dentist whose treatment plan I'm focusing on saw me 10 months ago, and of these two teeth, #15 was not to receive any treatment unless it was one of the "reobturation of the old silver fillings" and #12 was to receive a veneer. Possibly the "deep decay" was not as severe when he saw me 10 months ago, so I guess I would ask him to re-evaluate those two.

One thing that this dentist said was that he felt his treatment plan, with the onlays and veneers, is better than crowning all the teeth, because crowning requires the removal of such a large part of the natural tooth. Is he on the right track there?

Sounds as if the choice between crowns vs veneers for #4, 5, 12, and 13 is a judgement call - I believe the price is about the same. He said that those teeth are so far inward that the veneers cannot bring the face out as far as would be ideal, but that they would certainly help.

For what it's worth, his prices are $500 for crowns / $500 for porcelain veneers / $253 for polymer ceramic veneers / $253 for onlays. If you wanted to see more about this particular dentist, for your own info or whatever, his website is Dr Noel Rivas in Puerto Vallarta, Mexico - his office is as new, modern, and up to date (at least as far as I can tell) as any I've seen in the US and is located in a new hospital - I was told that if his office is in that hospital, he must be good.

Is there any way for a patient to know if the doc is using a good lab?

so, you've been very helpful. if you could reply to this, I'd appreciate it so much. I'll punch in another $15 right now if that seems reasonable.

Customer: replied 7 years ago.
I just tried to add another $15 but it said "service unavailable. ??
Well, if your bite is that far off to begin with, then you would be looking at either orthognathic surgery, which is rather unpleasant, or the placement of onlays in the posterior teeth to provide the necessary contacts. But if onlays are to be used, then make sure the dentist take upper and lower impressions, pour up the stone models, and perform a diagnostic wax build-up. Bite registration needs to be taken as well so that the lab will be able to mount your models correctly to approximate your bite when building the onlays.

If you had deep decay that was diagnosed 10 months ago, it is more than likely that the situation has gotten worse. So if nothing else, I would go into the procedure believing that RCT will be necessary and if somehow it turns out not to be the case, then we'll feel fortunate and lucky. Once a cavity breaches the enamel surface, it no longer needs external food sources. It can feed upon the organic material of the "dentin" layer.

As for the material used... it's possible that Dr. Rivas hires his own lab techs and may have his own personal lab. You will have to ask him if this is that is the case or not. In any case, if possible, you should request that traditional Porcelain-fused-to-metal (PFM) crowns use "high noble metal" only.

As for the veneers on the bicuspids, the thicker the veneers will be, the greater the likelihood of them falling off. That's because the bonding agent is weak to "shearing" forces. So the thicker the veneer (to compensate for the concavity of the arch), that would mean the more leverage the veneer will place on the tooth and torque will be magnified.

The website looks pretty good. That said, I can only assume he's got good moral and ethical standards. These days, it's easy to hire some ad company to put up a fancy website so I wouldn't use that to gauge the skill nor professionalism of the dentist. I also wouldn't hold it against the dentist either.

I'm not sure if Just Answer has changed the format for customers to pay. In the past, if/when you accept the follow-up answers, you would be billed the additional "deposit" fee for every subsequent accepts. (I'm not sure if this is still the case.)


Jul***** *****, DDS
Julian Chen and other Dental Specialists are ready to help you
Customer: replied 7 years ago.

Thanks again - you are certainly helpful and I understand what you say pretty well.

Is Zircon a "high noble metal"?

Since I visited Dr Rivas last March, I know that it's not a case of just a fancy website with pictures of someone else's office, and he seemed absolutely professional and thorough and caring, but I guess there's no way of knowing for sure. Unless I knew others who had been treated by him, but, of course, I don't, since it's in Mexico.

I believe Dr Rivas does not do any lab work, so would there be any way of knowing the quality of the lab(s) he uses - other than the question of "high noble metal"?

The purpose of the onlays, as I understand it, is to build up the height of the teeth so the bite meets better. I do not believe that my jaw has ever been out of place, just that the wearing down of the teeth from grinding now prevents the lowers from meeting the uppers properly.

About the preparations, Dr Rivas said he would take impressions, then something about "articulate", then study the bite, then do temporaries, then prepare the teeth, then final impressions, then place temporaries. Somewhere in there was "models to the lab". I don't have this exactly as he said it, as it's from notes and memory, but do these things seem to indicate he's on the right track and doing all that should be considered?

Re: veneers - he carefully pointed out that the veneers should only build up the tooth face so much - that if they were too thick, they would interfere with brushing, and also something about the gums need stimulation from chewing to remain healthy or to not recede or something, and if the veneer is out too far, the gums won't get the stimulation.

He said that my smile will be close to as good as it would be if all teeth were crowned, but that avoiding crowns, when possible, is good because crowns destroy all tooth enamel.

will appreciate your thoughts on these things - I think you are helping me gain some confidence in the procedures, but please don't hesitate to be blunt if you see any red flags here.

I'll go to work on the additional fee or bonus right now. thanks very much


At least from your accounts of the conversation/consultation you had with Dr. Rivas, it sounds as though you're in good hands. The impressions should be taken of both the upper and lower jaw, a bite registration taken and that will be used to mount the study models on an "articulator". Then your teeth can be studied and then wax build-up can be done to determine the thickness of any onlay or composite build-up that will be placed to even out your bite.

The only thing that didn't quite add up for me was you saying "the wearing down of the teeth from grinding now prevents the lowers from meeting the uppers properly." Typically, when a patient is a heavy grinder/bruxer, the back teeth will be worn short and flat, but they still occlude properly so that there's no problems of getting your back teeth to touch. The problems arise when we're trying to restore the anterior teeth for cosmetic purposes. We'd typically want to lengthen those front teeth so they appear more youthful, but doing so, would create bite problem for the back teeth. Or if we do not "open your bite" to compensate, then within a matter of weeks/months, your own grinding habits would knock out and destroy the expensive cosmetic work done on the front.

But that is something that you and Dr. Rivas can determine and at least from what you've described thus far, it sounds as though you should be in good hands from a technical standpoint. I, too, agree with Dr. Rivas that whenever we can preserve natural tooth structure (instead of grinding it away for crowns or fillings or veneers), we should strive to do so. Very rarely is anything that we do in Dentistry better than what mother nature has provided us with.

*edit* Forgot to address the question regarding "Zircon". Instead of metal underneath the porcelain crown, there is a zirconium substructure that the porcelain is glazed upon. (Similar to cubic zirconia.) These crowns have similar properties to traditional PFM's (same strengths and weaknesses), but the substructure is not metal, therefore, they can be made to appear more natural and cosmetic.


Jul***** *****, DDS
Julian Chen and other Dental Specialists are ready to help you
Customer: replied 7 years ago.


Thanks again. So helpful.

So, the porcelain on zircon is a good thing? Am I understanding that right?

And, if he's proposing porcelain on zircon crowns, is that a bit of an indicatin tht the lab work will be good?

I guess my biggest uncertainty now is the aesthetics, as far as the front teeth are concerned - the 6 upper front teeth would all be crowns, and the lowers would be reshaped or some built up or whatever, so that my smile - every tooth in it - will be new, shaped by someone in some lab. How the heck do I have any idea if the appearance will be great for me and my face/smile, or just maybe technically great but not right for me and my face/smile? It's sort of an artistic / judgement thing. I mean, I'm not George Clooney, but I'm aware that a lot of reconstructed smiles look artificial and/or wrong for the person's face. What do you think?

Zirconium-based crowns are generally more cosmetic and can be made to appear more natural (by well-trained lab technicians). However, the zirconium substrate needs to be properly grown and treated and there have been reports of premature failures if this process is not done properly.

There's no way for me to know whether the lab Dr. Rivas uses knows how to properly treat the zirconia. For instance, the lab that I send my work to, the zirconium substrate is actually made at a different location and when I get my crowns back, I get a 3M sticker/label with a serial number for tracking and assurance for that particular crown. I don't know if the 3M contractor/facility is much cheaper down in Mexico to make it so that Dr. Rivas can still be "profitable" charging those fees using official 3M processing. That maybe something that you can also ask Dr. Rivas.

The problem with a zirconium-based crown is that if not done properly, the bonding between the porcelain and the zirconium can be weak and insufficient. This can lead to the porcelain separating from the substrate and the porcelain then fractures. If this happens, then you'll need to replace the entire crown (zirconium and all).

I can only assume that Dr. Rivas will discuss the final appearance/shape of these teeth with you before proceeding to final restorations. Oftentimes, when you are in the temporary crowns (we call them "provisionals"), that is the time where you need to carefully study your smile and the shape of your teeth. If you're happy with it, then tell Dr. Rivas you like the shape and you'd like your final crowns to look the same. (They won't be exact but a good lab tech can make them very close in appearance.) If you feel the provisionals are too square, or round, or triangular, let Dr. Rivas know ASAP so he can tell the lab tech to do differently. And/or he can make the adjustments to the provisionals, have you walk around and evaluate again. And once you finally decide on the shape that you feel works best for you, he can take an impression of those teeth and send the impression to the lab for them to follow.

That is usually the best way to communicate to the lab tech on how we'd like the restoration to appear shape/contour wise.


Jul***** *****, DDS
Customer: replied 7 years ago.
Thanks very much. You're very helpful. I'm done for now. If I have further questions in the future, is there a way that I can reach you again?
I believe you can post to this particular question again (even if it's weeks/months from now) if you'd like me to follow-up with anything. That will then send me an e-mail to respond. Or, you could start a new question and if you want, you can specify the expert to answer your question (so you can pick me or some of the other knowledgeable experts).

Best of luck to you.


Jul***** *****, DDS