Subscribe to this PostDr. Malik asks:
I recently took a full day course in fixed dental implant prosthodontics.
What I
was expecting was a course in dental implant-supported crowns and bridges. What
we
actually had was a full day course in fixed-detachable (i.e., hybrid or
high-water) bridges for the edentulous mandible.
The prosthodontist
giving
the course has had great success with this design. I have never seen
any
patients with this kind of fixed prosthesis. I think it looks
terrible.
Are patients accepting this kind of fixed prosthesis? Are any of you
doing
this kind of restoration?
Dr. Malk: One of the reasons you are confused is because of nomenclature!
When it was new, 20 years ago, a fixed hybrid was of denture teeth, acrylic and gold supporting framework. Written in another country, we had hybrid prostheses as well, metal ceramic is a fixed hybrid of metal and ceramic material. Acrylic and gold used to be a periodontal prosthesis standard.
Then someone wanted to define the complete denture prostheisis from a removble one so the fixed-detachable prosthesis was discussed but it was to differentiate who would remove, patient or dentist and how removable vs fixed when the Milled bar and spark erosion technology was introduced.(Is it important?)
Depending on what you want to describe in the literature:
A fixed prosthesis (vs removable)
Fixed complete denture or implant supported fixed complete denture to be more specific.
Implant overdenture (always removable)
Implant supported overdenture (more specific – 2, 3, 4, 5, 6 implant supported)
High Water or is it High saliva? Fixed detachable bridges is too generic or vague because it could be a fixed 3, 4, 5, unit bridge, fixed metal ceramic prosthesis.
Your question says it all! and the answer is Yes, fixed lower prostheses or fixed comlete prostheses are still being accepted by most patients that have no mandibular dentition or supporting residual ridges.
The options today are improved designs using titanium frames, Hybrid ceramics of porcelain and composite, porcelain teeth, acrylic resins, and even all metal ceramic fixed complete dentures.
So Dr. Malk: If the dentist was showing fixed prostheses that were to years old using long retaining abutments, the tissue must have been very healthy but unesthetic by modern criteria. But the design has proved successful for over twenty years.
If Osseointegration has proven success and not survival, then let your imagination and a technicians help you to improve the esthetics and functionof your patients.
Excellent comments by RTYDDS – nomenclature is a huge problem. So is the outdated concept of the ‘high-water’ prosthesis. All of these restorations have one thing in common – they are ‘hybrid’ prostheses in that they restore a ‘composite’ defect (loss of more than one tissue type – teeth, gingival tissue and bone). The prosthesis can be PFM with pink porcelain or processed denture acrylic. The obvious advantage of the processed acrylic restoration is the ease of repairability as compared to PFM. Rather than a ‘high’ water design, we have used the Profile Prosthesis for many years now (Pract Periodont Aesthet Dent 1999; 11(1):143-151). With precision processed, custom tinted acrylic and high quality denture teeth, it completes easily with porcelain. The framework is inside and wrapped by the acrylic and the acrylic is ovate in shape and goes right to the tissue. Email me if you would like some photos, mark.adams@ddssolutions.net.
Thanks to Dr. Yanase for his succinct comments on nomenclature. Yes it has been a problem but the picture is beginning to become more clear. The designs we previously used are hopefully no longer being utilized with the development of titanium, laser welded frames, etc. The fixed lower bridges are accepted very well by the patietnts and to the best of my knowledge my patients have been well satisfied with this type of prosthesis for about 20 years now.
Athough one advantage of a processed acrylic resin hybrid prosthesis may be ease of repair, its biggest disadvantage is increased wear over a shorter period of time. I have seen these cases wear rapidlly when opposed by natural teeth or ceramometal restorations. Replaceing worn acrylic teeth is an inconvenient costly procedure for the patient and dentist. It is time consuming and not so profitable even for those of us with in-house laboratories. Pretreatment identification of a patient that exhibits significant parafunctional activity, bruxing and/or clenching usually contraindicates the use of the acrylic denture teeth variation of the Hybid prosthesis in my opinion for that patient. The ceramo-metal variable that is fixed-detachable is more difficult to fabricate but less likely to require frequent maintenance. When a ceramic failure occurs it can be repaired by fabricating a small ceramic addition that is bonded to the existing ceramic like a laminate to the existing ceramics by etching, silanating and bonding both ceramic surface together. I often use metal occlusal surfaces on maxillary fixed detachable hybrid prostheses because the maxilla especially loses a great deal of force and pressure discrimination with the loss to the periodontal ligament when teeth are lost and predisposes the prosthetic to signifant wear especially in the parafunctional activity patient. Evidence of long turn metal wear lead me to fabricate an acrylic resin nightguard appliance for these cases as well.
Hybrids and fixed PFM have their own specific indications.
when interarch is large due to excessive soft and hard tissues deficienccy and patient refuses for removable(by him/her self),
PFM bridges is another choice but PFM bridges are esthetically inferior in that condition,even use of pink porcelain dose not mimic gingival tissues accurately,particularly in elderly patient with small maxillary ridge arch with large mandibular ridge arch.
Another major indication for hybrid is difficulty in placing implants in exact locations for teeth being replaced for proper esthetics and gingival embrasures.
It may happen due to poor treatment planning or ptient’s refusal for grafting procedures.
As other clinicians mentioned, due to todays advanced technology HYBRIDS are in fact eshetically more desirable.
I teach in institution where we do HYBRIDS when ever they are indicated and believe me esthetically patients are very happy.
Please advise techniques for an esthetic hybrid. I have some cases coming up that I planned for overdenture, but would like to see if there are alternatives. Maxilla have 6 implants, and mandibles have 4. All are mostly placed in the anterior region, but with decent ap spread.
I have enjoyed reading pro and cons on hybrid dentures, however i have seen in my 35 years of lab work experience that acrylic really does not hold up as well. With new cad cam designs {atlantis| and others to me it is a win win fabricating a all porc, hybrid denture with highly polished metal and beautiful glaze on porc. How could you go wrong? As far as the fear of porc. fracture, well the rule is always the same. Proper metal, or zirconia frames design is still very important, and this is the area that i feel restorative doctors should be aware of. Treatment planing and team work is so very important from the surgeon, restorative dentist and a qualified dental techntian.
Mr Grgas: Thanks and point well taken!
Very nicely discussed by all clinicians. Hybrid vs PFM : both are decided by indications. Hybrid is specially we prefer in old patients to give more fullness to face and better esthetics.