Esthetic Dentistry - Science topic

The material is Graphy's Tera Harz material

Composition: Tera hard TC-80 is an LED curing polyurethane based resin suitable for 3D printing characterised by high tensile strength, high abrasion resistance and non toxicity

..https://www.ijdsir.com/issue/page/2872/Aesthetic-reconstruction-of-Ellis-class---fractured-lateral-incisor-using-Partial-bonded-restoration--A-case-report.

It's a tough situation. The patient that you have described is one who has a physical disability that compounds their condition So you can really feel for this person. But we have to make sure that we listen to them with empathy while at the same time thinking about offering solutions that are physical rather than emotional. When you say that patient is impatient and does not comply with splints I would agree that this is probably true but to a great extent if they don't comply with the splint therapy they may well never achieve successful treatment.

Sadly, we can't treat everyone. Some people are refractory to treatment. For some patients, if they can't identify the problem we will never know if there is a solution for it.

A good friend of mine, when speaking to patients will tell the patient that they understand that the patient has a problem but the patient needs to understand that it is their problem and it doesn't get any better by making it the clinicians problem. It becomes an ownership of the problem situation. I can never own the patient's problem, the best I can do is try to help them treat it. So, once again, coming back to the statement that the patient grows impatient with splint therapy this makes sense to me but I can only help to solve a problem that has been developing for years and years (was this patient in their 70s) but any solution that I offer the patient is not going to have the immediacy that they would so desire. This patient will frequently become a dental shopper rather than becoming a dental patient.

Dr. Yim's response is a classic description of how you create gingival form once osseointegration has occurred.

Many would argue that the time to do this is not after osseointegration has been achieved but would be preferred as a technique that should be provided at the time of implant insertion. So this would be immediate implant insertion ( at the time of tooth extraction) with insertion of a provisional restoration on that same day.  That provisional restoration should exhibit the contours that you would want for the final restoration with a few caveats. The idea is that if the provisional restoration has the contours that you want that the soft and hard tissue will heal to those contours. To ensure that this occurs or to at least increase the likelihood that it occurs  you could move the gingival emergence further towards the incisal edge on the provisional restoration. Assuming that the soft tissue heels to the contour that you've established this then means that when you make your final restoration you would have an excess soft tissue (and hard tissue ) to compress on the soft tissue slightly (with the final restoration) which would put the soft tissue where it would be most desirable from an esthetic and  phonetic standpoint.

Years ago, when we were not talking about immediate implant placement, when all implant placement was performed with healing abutments and removable non-loaded provisional restorations, there were these discussions of "training" or conditioning the soft tissue after osseointegration had been achieved to make it cosmetically acceptable. The idea works great if you have excessive soft and hard tissue but if you have deficient soft and hard tissue making that deficient tissue "grow" is and always has been unpredictable.

You can do things like secondary soft tissue grafting after the implant has  achieved osseointegration with the surrounding bone to compensate for deficient soft tissue and you can do bone augmentation to compensate for inadequate bone dimension but you are unlikely to achieve predictable re-integration of an implant surface that has been in contact with soft tissue and/or the oral environment. Although there certainly are people who show radiographic images taken at some point after they created regenerative procedures this does not mean that it happens every time. We all have images like those but to suggest that they are absolutely predictable would be a pretty big stretch.  I would probably put it a different way and suggest that we don't truly understand why this works sometimes and why it fails to work other times. To suggest that such grafts are unpredictably predictable might be more realistic.  Yes I understand the oxymoron in that sentence.

Getting back to the original description of an integrated implant and then using progressively modified provisional restorations to train the tissue to a position that you wanted it to be seems like a nice, artistic way to do this. If it's predictable, why not just make the provisional restoration  or even the permanent restoration at the contours and dimensions that you so desire, once again assuming that there is excessive soft and/or hard tissue?  After all, the provisional restoration is probably fabricated from a porous, at the least relatively porous, polymer surface whereas the definitive restoration is much more likely to be a less porous, sometimes almost nonporous, ceramic material. That definitive restoration made with the ceramic material should be much kinder to the surrounding soft tissue. Why a porous polymer is the recommended approach to "train" soft tissue is a question that I've never seen anyone answer in a compelling and convincing way. If you can train the tissue to a certain position why can't you just make it happen in one step with a more favorable restorative material?

Please indulge me in a tangential discussion.

Think about it, If you violate the Biologic width on a natural tooth, what happens?  Certainly sometimes the response will be tissue recession away from the Biologic violation. I mean the body has to respond to this Biologic violation by remodeling itself in some instances.

We know that patients can have gingival recession occur that may be somewhat self-limiting. Have you ever seen an orthodontic patient where the teeth were moved outside of the labial plate of bone creating a soft tissue recession that mimics the underlying bone.   I guess we could say that soft tissue recession should have an etiologic  factor or factors  but we certainly have clinical situations where it is really perplexing to describe the etiology of every instance of soft tissue recession.

Classic  description of a biologic width violation is that you will see inflamed hyperplastic or hypertrophic tissue in response to a Biologic width violation. Why doesn't the tissue just recede in response to that violation ( and the associated inflammatory response) thereby forming a new equilibrium?

Let's think about the situation above  While considering what happens with natural teeth we have reactive gingivitis do we always have responsive periodontitis? The answer is no, You absolutely can have gingivitis and not  see that gingivitis progress into periodontitis. If one disease was 100% associated with the other then we don't need two distinct diagnoses, instead what you would have phases of one disease entity.  Iif bone always responded to gingivitis, there is one diagnosis that needs to be described at different phases of the same disease process. (which is not the case, gingivitis is not always a consistent progression towards periodontitis with associated periodontitis)

To me this is what always makes Biologic Width violation a difficult concept to embrace without any hesitation. We should  all recognize biologic width when it is occurring but how many violations have occurred with the apparent soft tissue response but without a hard tissue response? What do we do when we see a violation of the biologic width?  Well what we hear about is resective  and/or re-contouring procedures of the soft and hard tissue.

Remember this is all occurring on natural teeth that have a periodontal ligament with bundle bone and complex gingival fiber orientations. Take out the tooth and you remove the Periodontal ligament then you place an implant and the bundle bone loses  vascularity. If the bundle bone was thin you likely lose bone height and bone width. How many times have we seen descriptions of how bone resorb's after a tooth is removed. They all basically say the same thing. So how do you combat it? One way to combat it is to remove the tooth preserves the socket and place an implant secondarily with a much thicker facial plate of bone on the facial aspect of the implant which is usually the aspect where the bone is thinner (if nothing is done to preserve it). Another way to combat the problem is to graft the defect between Implant and surrounding bone assuming that the surrounding bone was maintained at the time of tooth extraction. If that graft is osteoconductive (Osteoconductive graft Autografts, treated al- lografts, and bone substitutes that provide a scaffold for osteoid formation.)  the chance of healing is pretty good. Another option is to prevent epithelial down growth with the implant placement in the extraction socket that has preserved the labial plate allowing bone to heal in the clot that forms between the implant in the existing bone. The trick of that is to have a sufficient gap dimension that will heal more rapidly in the form of osseous tissue than it does in the form of soft tissue going into the defect area.

Why did I bring up Biologic width?   I would suggest to you that this topic was brought up because we look at implant placement and soft and hard tissue contours as if they were in entirely foreign concept relative to the concept of Biologic width on natural teeth. If we have to make a transmucosal abutment and a crown the D connects to that trans mucosal abutment and both of those occur above the level of the Implant  Restorative platform and we measure the distance between that restorative platform and where the restoration begins what we are going to find is that if this were analogous to a natural tooth setting it would be at very high risk of a Biologic width violation wouldn't it? So is it a different biologic situation that we are looking at with the avascular implant placed within a bony housing in situations sometimes where there is very little bone to the facial or to the palatal or lingual of the implant thereby compromising the vascular supply. Does this lead to a situation where we more frequently should consider soft tissue grafting particularly with connective tissue and epithelium or perhaps just with connective tissue to create a better vascularity to the tissue on the facial aspect of the implant?

I know this started out as a simple question of how you achieve the emergence profile that is favorable on a dental implant but if we think of that simple question there are a lot of different opportunities for discussion. I'm just breaking the surface here.

Here is an interesting paper on expired composites: 

Wax up and double scanning work very well on smile creation.

I wonder if OHQoL and KAP are so conceptually different that it would be unlikely to find a model that links them.   

can you read the followings studies

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J Contemp Dent Pract. 2014 Jul 1;15(4):392-8.

Influence of Fluoride Concentration and pH Value of 35% Hydrogen Peroxide on the Hardness, Roughness and Morphology of Bovine Enamel.

Nascimento WC, de Lima Gomes Ydo S1, Alexandrino LD1, Costi HT, Silva JO Jr, Silva CM.

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Sichuan Da Xue Xue Bao Yi Xue Ban. 2014 Nov;45(6):933-6, 945.

[Effects of vinegar on tooth bleaching and dental hard tissues in vitro].

[Article in Chinese]

Zheng LW, Li Di-ze, Lu JZ, Hu W, Chen D, Zhou XD

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Oper Dent. 2014 Dec 23. [Epub ahead of print]

Effects of the Concentration and Composition of In-office Bleaching Gels on Hydrogen Peroxide Penetration into the Pulp Chamber.

Mena-Serrano A, Parreiras S, Nascimento ED, Borges C, Berger S, Loguercio A, Reis A.

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.J Esthet Restor Dent. 2014 Dec 20. doi: 10.1111/jerd.12123. [Epub ahead of print]

Evaluation of Novel Microabrasion Paste as a Dental Bleaching Material and Effects on Enamel Surface.

Bağlar S, Çolak H, Hamidi MM

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J Int Oral Health. 2014 Jul;6(4):18-24.

Microhardness and roughness of enamel bleached with 10% carbamide peroxide and brushed with different toothpastes: an in situ study.

Melo CF, Manfroi FB, Spohr AM

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Eur J Dent. 2014 Jul;8(3):320-5. doi: 10.4103/1305-7456.137634.

Effects of a bleaching agent with calcium on bovine enamel.

Alexandrino L, Gomes Y, Alves E, Costi H2, Rogez H, Silva C1.

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BMC Oral Health. 2014 Sep 6;14:113. doi: 10.1186/1472-6831-14-113.

Does post-bleaching fluoridation affect the further demineralization of bleached enamel? An in vitro study.

Kemaloğlu H, Tezel H, Ergücü Z.

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See comment in PubMed Commons belowOper Dent. 2015 January/February;40(1):96-101. Epub 2014 Aug 19.

Effect of Hydrogen Peroxide Concentration on Enamel Color and Microhardness.

Borges A, Zanatta R, Barros A, Silva L, Pucci C, Torres C.

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See comment in PubMed Commons belowActa Clin Croat. 2013 Dec;52(4):419-29.

Surface changes of enamel and dentin after two different bleaching procedures.

Klarić E, Marcius M, Ristić M, Sever I, Prskalo K, Tarle Z.

One answer is  8-12 microns -Riis and Giddon

Other workers in this field that you should check were were Anderson and Picton

The snap on smile used to be called a Hollywood bridge.  It was used for short term use and mainly as a diagnostic tool to determine if the future cosmetic result would be acceptable to the patient.  Unless it is acceptable , no further treatment is performed. Thus, the patient's mouth is not altered unless it is acceptable using a reversible diagnostic tool.

There are a variety of studies to support the feasibility of implant and tooth supported removable partial dentures

Clinical Outcome of Double Crown-Retained Mandibular Removable Dentures Supported by a Combination of Residual Teeth and Strategic Implants.

Rinke S, Ziebolz D, Ratka-Krüger P, Frisch E.

J Prosthodont. 2014 Sep 14. doi: 10.1111/jopr.12214. [Epub ahead of print

Unsplinted implants and teeth supporting maxillary removable partial dentures retained by telescopic crowns: a retrospective study with >6 years of follow-up.

Frisch E, Ratka-Krüger P, Wenz HJ.

Clin Oral Implants Res. 2014 Apr 16. doi: 10.1111/clr.12407. [Epub ahead of print]

Implant retention and support for distal extension partial removable dental prostheses: satisfaction outcomes.

Gonçalves TM, Campos CH, Garcia RC.

J Prosthet Dent. 2014 Aug;112(2):334-9

Implant Tooth-Supported Removable Partial Denture with at Least 15-Year Long-Term Follow-Up.

Mijiritsky E, Lorean A, Mazor Z, Levin L.

Clin Implant Dent Relat Res. 2013 Dec 27. doi: 10.1111/cid.12190. [Epub ahead of

Prognosis of implants and abutment teeth under combined tooth-implant-supported and solely implant-supported double-crown-retained removable dental prostheses.

Rammelsberg P, Bernhart G, Lorenzo Bermejo J, Schmitter M, Schwarz S.Clin Oral Implants Res. 2014 Jul;25(7):813-8.

Survival of double-crown-retained dentures either tooth-implant or solely implant-supported: an 8-year retrospective study.

Schwarz S, Bernhart G, Hassel AJ, Rammelsberg P.

Clin Implant Dent Relat Res. 2014 Aug;16(4):618-25.

Implant placement under existing removable dental prostheses and its effect on oral health-related quality of life.

Wolfart S, Moll D, Hilgers RD, Wolfart M, Kern M.

Clin Oral Implants Res. 2013 Dec;24(12):1354-9

Dental implants as strategic supplementary abutments for implant-tooth-supported telescopic crown-retained maxillary dentures: a retrospective follow-up study for up to 9 years.

Krennmair G, Krainhöfner M, Waldenberger O, Piehslinger E.

Int J Prosthodont. 2007 Nov-Dec;20(6):617-22.

Removable dentures with implant support in strategic positions followed for up to 8 years.

Kaufmann R, Friedli M, Hug S, Mericske-Stern R.

Int J Prosthodont. 2009 May-Jun;22(3):233-41; discussion 242

Use of dental implants to improve unfavorable removable partial denture design.

Mijiritsky E, Ormianer Z, Klinger A, Mardinger O.

Compend Contin Educ Dent. 2005 Oct;26(10):744-6, 748, 750 passim

A solid statement indeed. May I please respectfully ask:

...based on which solid scientific evidence?

The initial polymerization contraction is 1.5-3.5%, which causes problems with bulk fillings shrinking away from margins, but has little effect on layered build-ups. Wear resistance and flexibility are built into the composite, but do not necessarily directly relate to polymerization shrinkage.

The osteoclast dysfunction define the pathogenesis of this disease. In addition, the whole bone metabolism is affected in the osteopetrosis patient, once the crosstalk between osteblast and osteoclasts is also deficient. The major concern is in fact the osteomyelitis. The orthodontist and the physician should discuss the patient’s risks and benefits of orthodontic treatment according to the severity of the osteopetrosis.

Agreeing with the finding that bonding to enamel is more reliable as bonding to dentin, the question can be refraised as: is it contra-indicated to place a porcelain veneer with cervical part bonded to dentin? I would think that a certain risk for imperfections such as marginal staining would be higher for those situations and should be explained to the patient, but still the veneer can be placed. Alternatives like full crowns also have their risk profiles such as pulp necrosis, fracture etc. Comparing the techniques and possibilities I think the minimal invasive option still has the most advantages.

To make it more complicated: what has a better prognosis: a veneer bonded to enamel in a high caries risk patient or a veneer bonded to dentin in a low risk patient?

These aspects are very suitable to be investigated in practice based, (retrospective) pragmatic controlled trial designs.

Let's think about this a little bit. Our personal opinions are going to be based upon our own personal biases. Our biases are often dependent upon the clinical experiences that we have had. Indeed in this subject we have a few different categories of assessment of the occlusal vertical dimension. We often times assess this dimension on the basis of the vertical dimension of rest. The vertical dimension of rest is established through different techniques: radiographic, tactile, phonetics, aesthetics, etc. the vertical dimension of occlusion is usually some measurement closed relative to the vertical dimension of rest. It varies on the basis of skeletal jaw relationship with the largest differential being associated with a class II skeletal relationship in the smallest differential ring associated with a class III jaw relationship.

The reality is that we will never really be able to test this through a randomized controlled clinical trial. The reason for this is that an RCT is going to be influenced by the skills of the clinicians running the RCT. So if you have a clinician who is very good at the radiographic assessment of the analysis of the vertical dimension of Rest that individual may not be very good at assessing the tactile method of determining the vertical dimension of rest. Consequently the person who is experienced and skilled in the radiographic technique who then develops and RCT testing it against the tactile technique will undoubtedly find that the radiographic technique is superior. All the while another clinician trying to replicate the same results was experienced in the tactile technique would find opposite results. Remember that the RCT is an exquisite method of eliminating bias or reducing bias. The problem is that bias is not the only factor that relates to research evidence. We have issues of consistency, directness and precision. You might want to look at: http://effectivehealthcare.ahrq.gov/index.cfm/search-for-guides-reviews-and-reports/?productid=328&pageaction=displayproduct

So when you ask the question about our opinions on the best method to establish the clues of vertical dimension what you will receive is an answer based upon "our opinions" and those opinions are going to be very dramatically influenced by our experiences, our mentors, etc.

Ultimately I think that you need to, in my opinion, address this situation from a couple of different aspects. When I look at the occlusal vertical dimension I invariably use the tactile method and combine it with the phonetic method and combine it with aesthetics. After the cast are mounted I look at the parallelism of the ridges. I don't do electromyography and it is rare that I do radiographic assessment although I do this from time to time. So all this is important for me. It might not be of any relevance to you. The reality is that these are techniques and techniques are skill-based and experience-based, they will differ from clinician to clinician.

I think a lot will depend on the patient's compliance and his or her willingness to retain their natural dentition...as far as i am concerned i would definitely try 2 save the natural tooth instead of blindly going 4 implant....surgical crown lengthening, root canal treatment, post and core should be done but ultimately it all depends on the patient's will and whether they would be ready to come for so many appointments for saving a tooth..if the answer is no...definitely implant therapy..provided the periodontium is healthy and we have sufficient sound bone to receive an implant...

I think the first step is to diagnose the problem. (Isn't this always the case?)

Was the implant placed too far to the labial to be covered by soft tissue?

Was the implant platform placed above the level of the osseous crest?

Was the implant placed in the correct position and then bone loss and soft tissue loss occurred?

The first two have no great solutions. The third problem is usually bone loss prior to soft tissue loss rather than soft tissue loss causing the bone to be lost.

Evidence for re-integration of a surface of an implant where the bone has been lost is weak. Perhaps one might suggest that it is beyond weak and there is almost no evidence for re-integration other than in animal studies where the bone was lost secondary to ligature inducement...most severe in coated implants (HA, TPS) and regrowth was best with coated implants. But this is old material.

Assuming that tissue follows bone, once the bone level is reduced secondary to bone loss then the soft tissue will usually also be lost. Gain of soft tissue with grafting over an avascular implant surface is unlikely unless there is a very narrow fenestration and then the soft tissue gain will not be thick or durable...it is likely to be lost again over time.

Some probably very helpful papers:

J Prosthet Dent. 2003 Dec;90(6):556-62. Factors determining post selection: a literature review. Fernandes AS1, Shetty S, Coutinho I.

Effect of the crown, post, and remaining coronal dentin on the biomechanical behavior of endodontically treated maxillary central incisors.

Veríssimo C, Simamoto Júnior PC, Soares CJ, Noritomi PY, Santos-Filho PC.

Effect of ferrule height and glass fibre post length on fracture resistance and failure mode of endodontically treated teeth. Abdulrazzak SS, Sulaiman E, Atiya BK, Jamaludin M. Aust Endod J. 2013

In general, I agree. A crown with an insufficient margin should be remade completely. If you want to transfer the insufficiency to the dental technician for adaption, you can use the following approach:

1. Cut back the margin of the crown in the area of the gap 1.0 mm superior to the margin of the preparation. Make sure that there is a pronounced chamfer.

2. Take an impression (e.g. polyether) with the positioned crown.

3. The dental technician should cast the impression with a special resin.

Because of the shrinkage of the ceramics during the firing process, the marginal fit will be tolerable at best. Because of the limited strength of the veneering ceramic (approx. 80 MPa) it should be implemented only in case of small areas with margin insufficiencies, using a special margin ceramics (available e.g. by Vita Zahnfabrik, Bad Saeckingen, Germany).

It depends on each patient self-healing capacity, but it is very important to keep the intaglio surface as much polished as possible and free of plaque. Some inflammation is possible. I recommend you to read two classic articles by John Kois and Joseph Kan on Compendium 2001.

by Public health dentistry. Meaning implementing relevant preventive dental health services to appropriate population groups.