- Details
- Published on 05 October 2011
- Written by Thierry SUPPLIE
- Hits: 298
Flexible materials "permanent" total prosthesis in which indications?
To forget the underside of a denture by means of a flexible material is an idea that seems sensible face some difficult clinical situations of total toothless. Indeed, it seems logical not to compress the lining between two hard structures, the prosthesis and the bone [1]. These flexible materials have been and are still subject to many misunderstandings, because if one side, they seem to solve, by their mere presence, most of the problems, on the other hand, some of their caractéristiquesireprésentent constraints that , if she is not taken into account, can lead to treatment failure. The purpose of this study is to fairele information on the use of these materials and possibly rehabilitate lesibases soft denture by demystifying. We propose a course of action (regardless of thetype of flexible base "always" used) both in terms of achieving that level of prosthetic laimaintenance and hygiene, eniessayant to have a more rational approach and most effective, because the most important is not to allow patients to recover a relevant social and personal life more harmonious?
the materials
The subject of this article concerneque flexible bases so-called "permanent" and in any case, the resins
Hydrocast delayed type-setting, Fitt ... The list of soft materials utilisésdans this study is not exhaustive but covers the four main families of products in the trade. Are:
Acrylic resins
These are polymethyl methacrylate "classic" soft parl'adjonction made of a plasticizer. It seems that this plasticizer evaporates and causes a hardening of the soft material in the short term [2]. However, these resins bind very well to the resin based rigid prosthetic since they are the same chemical nature. The implementation of the laboratory is easy. In this family, we find the Vertex (1), thermal polymerization, and Perform Soft (2), which is light-cured.
silicones
They are flexible in their chemical nature. They have non-stick properties vis-à-vis micro-organisms, but in return it is necessary to use an adhesive and a metal casting interface (mechanical connection) pourrelier the flexible material to the resin base: were used the Lutemoll (3), which is pressed and cured at high temperature (nearly 200 ° C), and Permaflex (4), which is pressed and cured at about 100 ° C.
Ethylene vinyl acetate (EVA)
They are thermoplastic materials containing antibacterial substances. They are flexible in
(1) Odoncia, 3, rue Michelet, 94853 Ivry-surSeine Cedex. Tel. : 01 46 58 06 96. Fax: 01 14 4672 81.
(2) Coltene Whaledent, 16, rue Louis Blanc, 93585 Saint-Ouen Cedex. Tel. : 01 40 November 02 47.Fax: 01 40 10 99 80.
(3) Bisico France, Opera, PO Box 60, 13680Lançon-de-Provence. Tel. : 04 90 42 92 92.Fax: 04 90 42 92 61.
(4) Kohler-Medizintechnik GmbH and Co KG, Danningen, 9, 78579 Neuhasem, Germany.
(5) Laboratories Mazeau Sari, France. (6) Hygienic Eudident-SA, PO Box 38, 95270Luzarches.
their chemical nature. Their connection to the rigid resin is reinforced by the use of an adhesive. The Flexital Plastulène (5) is the most famous member of this family. Its implementation requires specific equipment and technique (it is injected, hot, in press). It comes as a cartridge ready for use.
the fluoroelastomer
The fluoroelastomer, represented Novus speaks (6), is a semi-organic, it is the only one that is radiopaque. It contains fungicide and bacteriostatic substances. Binding to the rigid base is correct, but requires the addition of an adhesive for safety. This product is packaged as a pre-mixed. It is heat curable and requires the purchase of any new laboratory technique.
All these materials have similar mechanical descaractéristiques: they are flexible and all have a modulus of 4.2 MPa and a coefficient of 0.47 Poissonde [3]. This means they make in every case a shock absorber to reduce the energy from the shock of masticatory forces [4] and can, as D. Buch [5], considered "solutionsanti-trauma."
In all cases, the flexible material ideal does not exist, know their strengths and weaknesses will take Lemeilleur party (or least bad) of such material.
Clinical indications for flexible bases "permanent"
Despite the many advances in dental disciplines, the denture still has its place: the hope and the environment deviates growing medical have resulted in an increase of very elderly patients and more and more difficult to sail.
The major indication of utilisationdes flexible bases "permanent" is represented by a class of partially or totally edentulous patients in whom surgery is any cons-indicated or refused either temporarily or permanently. The surgery will be against-indicated with:
- The major risks of osteoradionecrosis;
- Specific disease states changing;
- Too large a senescence;
- un refus psychologique (phobie ou traumatisme).
For these patients, in whom surgery is not feasible, ilfaudra any time to address the following issues:
• mucous membranes thin and fragile that do not support the touch of a hard resin: the flexible base will provide a better tolerance of dentures and comfort;
• irregular peaks (Fig. 1) on which it is very difficult due to lack of surgical correction, the appropriate distribution pressures: the prosthesis combined with a flexible base will minimize overpressure assurantune better stress distribution;
• the strong resorption in the mandible, with the emergence of the mental nerve: the damping produced by the flexible material will improve the confortet preserve the remaining bone support
 |
|
Fig. 1 - irrégulièresne peaks can be in this case managed by surgery. |
• a reduced bone support against a natural dentition (Fig. 2) aggravated by a class II of England: the flexible base will allow the patient to have little contact with concentrated support and preserve the tissue desoutien
• after fracture, the establishment of an osteosynthesis system (Fig. 3) makes it difficult to wear a prosthesis. The use of a flexible leads to decreased pain phenomena and the stress transmitted to the bone, while making a bet based on "soft" bone;
• loss of substance with skin graft (Fig. 4) are essentially of consecutive patients operated on oncological but also due Ades ballistic trauma (biological context more favorable for the healthy and stable). In these cases, a prosthesis doubléed'une flexible base is the only alternative.
These situations show what trade-off will not be easy to get a functional prosthetic rehabilitation, especially as the use of a flexible base can not, under any circumstances, overcome technical failure [1] or permit to waive the performance criteria of complete dentures in general.
There are other indications of the use of soft denture bases:
• Pedodontics: young edentulous patients, the denture lined with a flexible base allows some adaptation to tissue remodeling and growth
• in partial denture when there is persistence of the block-incisivo canine and resorption very important sectors lateral and rear base makes a flexible support of non-traumatic support ostéomuqueux deficient
 |
|
Fig. 2 - facing natural teeth a |
 |
|
Fig. 3 - allow flexible bases pressing |
 |
|
Fig. 4 - On skin grafts, permetun |
• in maxillofacial prosthesis: in the transient phases, this type of prosthesis promotes the acquisition of compensatory reflexes before the final prosthesis;
• In case of refusal following a psychological phobia or, most often, injuries to many interventions: the flexible base while providing an alternative (and only) non-aggressive and therefore accepted by the patient.
Case report No. 1
This patient aged 80, a former soldier, does not support the mandibular complete denture. He complains of his mobility and highly sensitive areas. He is satisfied with his maxillary complete denture. Endo-oral examination revealed a thin mucosa and painful in places and a flat bearing surface (Fig. 5) in the presence of a muscle "energetic." The panoramic radiograph revealed a very significant reduction with emerging mental foramina (Fig. 6). In accordance with the patient aware of the pros and cons of treatment, it was decided to perform again a mandibular complete denture base coupled with a flexible, so-called permanent.
In view of the periprosthetic very tonic, it has conducted primary and secondary fingerprints anatomo-functional wax (Ex-3N of Etn Meister, Nuremberg) (Fig. 7 and 8).
 |
Fig. 5 - The surface is flat muscles toned. |
 |
Fig. 6 - significant resorption. |
   |
||
Fig. 7 - Footprint primary wax. |
Fig. 8 - Imprint secondary wax. |
Fig. 9 - The prosthesis use, in the mouth (Flexital-Plastulène). |
The flexible base used for the realization of the mandibular denture was the Flexital-Pastulène (Fig. 9).
The patient has seen the disappearance of sesdoléances and also received important unconfortable. He accepted the constraints of this type of treatment and is very aware of the role it should play himself in the durability of the prosthesis.
Case report No. 2
This is Mr. C., 69, sent by the ENT department at the hospital. He was treated by chemo-and radiotherapy for cancer of the parotid gland left. This patient is edentulous and has never been paired. It presents major risks for ostéoradio necrosis.
Clinical examination shows the maxilla (fig. 10), a support surface with two large tuberosities and mobile. In the mandible, the remnants of a problem avulsions (Fig. 11) by their bumpy terrain. There is a deficit saliva but that does not compromise the maintenance of full dentures.
The treatment plan chosen was to conduct a complete denture bimaxillary coupled with a flexible basis in order to manage the distribution of stresses on the bone relief and to avoid any break in the mucosa. The maxilla, a special impression technique was performed to record the tuberosities mobile and hypertrophied (Fig. 12 to 15). Very close monitoring and frequent visits are allowed this patient emaciated and in a state of psychological distress to feed and regain a more positive image delui (Fig. 16).
 |
|
Fig. 10 - The two mobile tubérositéssont
|
Fig. 11 - The support surface mandibular |
 |
|
Fig. 12 - Production of secondary
|
Fig. 13 - The spacings are released, |
 |
Fig. 14 and 15 - The footprint of the two tuberosities is made in plaster
|
 |
Fig. 16 - use denture lined with Novus. |
|
Case report No. 3 Mrs. S., 68, comes to see an improvement in the aesthetics of the mandibular denture very old and revised. It also asks whether it is possible to increase the stability of the prosthesis. It is a tidy and elegant woman. The examination revealed a congenital asymétriefaciale treated by surgery at the age of 50. Many setbacks, following this intervention, resulted in a significant loss of tissue on the left. The disfigurement is important (Fig. 17). A bone graft was performed auniveau left of the horizontal branch of the mandible with a conjunctival graft at the floor of the mouth in the area.
|
Physical examination shows a support surface highly discordant (Fig. 18), with muscular hypotonia gauche.Au maxilla, is present in a natural dentition. The panoramic radiograph shows the extent of the difficulties in managing (fig. 19). In addition, this patient has a severe Angle Class II (Fig. 20). Given all this, the treatment plan proposes the creation of a mandibular complete denture lined with a flexible base (fig. 21). The achievement was made prosthetic conventional manner. However, once the prosthesis is completed, it was made a recording of the upper prothèseau using a plastic resin Aprisa delayed by the Hydrocast. A second firing has perfect all the support muscles (Fig. 22 and 23). Without solving the problem of loss of substance to deface, aesthetics is satisfactory and its setting has been followed step by step by the patient. The treatment of these clinical cases shows that flexible bases have an important role to play in addressing certain clinical situations and should be considered as a treatment in its own right and not as something marginal, it is true that anatomical and functional issues present, are often added anxiety or psychological distress. To establish the relationship between the patient and the practitioner is, in these cases, a value of paramount importance. If the databases can provide a flexible solution (sometimes the only) Aces clinical situations, it is important to know that there a number of constraints on the nature of these materials and that can not be overcome. The practitioner, but the patient must be informed and aware to make the most.
|
Problems encountered in the use of flexible bases. Solutions?
Despite the great services provided by the flexible bases, a number of inconveniences have arisen:
- Fractures of the mandibular prosthesis due to the thinness BEYOND resin base in some areas (Fig. 24);
- Changes in color (fig. 25);
- Tears (Fig. 26);
- Degradation of the surface (Fig. 27);
-bacterial colonization (Fig. 28) due certainly to the material, but also to poor hygiene.
The great difficulty in the development of these manifestations of aging is that these phenomena are not systematic, come in various aspects and can not predict the onset time. However, we tried (since we can not intervene in the material itself) to reduce some of these problems at different levels:
• in respect of the surface: when observed under a microscope the surface of the intrados, the porosities remarquedes specific material, but also, quite frequently, micro-inclusions of gypsum (Fig. 29) and growths of flexible material. These defects are due to errors accumulated over desdifférentes stages of the prosthetic and the use of unsuitable materials. Polishing operations are limited to soft bases.
In terms of impression materials side, we recommend the use of silicone or thiokol for a smoother surface and more homogeneous (Fig. 30 and 31). In the laboratory, it is necessary to comply with the protocol established by the manufacturer and use a type IV plaster (hard, low porosity). Finally, it is preferable that a flexible implementation will print. Hygiene techniques will be in the greatest respect for this state desurface: soft brush, suitable products
 |
Fig. 22 - Registration of the upper. |
 |
Fig. 23 - Second cooking
|
 |
Fig. 24 - Fracture (usually in the middle). |
 |
Fig. 25 - Staining. |
 |
Fig. 26 - Tearing of flexible material. |
 |
Fig. 27 - Deterioration of the surface. |
 |
Fig. 28 - Bacterial colonization
|
 |
Fig. 29 - outgrowth of flexible material and traces of plaster (x20). |
|
• the risk of fracture is far from negligible when performing a mandibular prosthesis combined with a flexible material, as it is done at the expense of hard resin, especially in the incisal area. It is therefore desirable to strengthen the base with a metal casting This interface does not affect the aesthetics or comfort and can proceed further in a reline without difficulty (Fig. 32 and 33) • stains can be the result of eating habits, making Medicis, techniques, inadequate hygiene or sometimes the flexible material itself: it is preferable to avoid using in these cases, acrylic resins (flexible) that appear less stable over time than lesautres materials • bacterial colonization of soft bases is the biggest criticism of these materials. As in other disciplines (periodontics, implantology ...), patients who received this type of prosthetic treatment are subject to maintenance "mandatory", with regular checkups. They are aware of oral hygiene techniques to make prosthetic. For all these reasons it is reasonable to advocate the use of these bases for a flexible medium term. Oral hygiene prostheticHygiene and prosthetic control are essential to maintaining the biocompatibility of implants. Hygiene procedure must be adapted to the nature of flexible bases and the practitioner must ensure that it is controlled by the patient. |
 Fig. 32 - Large bar renfort.Hygiène oral- Daily brushing bearing surfaces with a soft brush; - This simple but effective method can be completed once a week by rinsing (2 min) with a solution of chlorhexidine gluconate 0.2%; - However, antiseptic mouth rinses should be used with caution as they may alter the delicate balance of the oral environment. hygiene prostheticDaily cleaning of the prosthesis is performed using a soft toothbrush or surgery (to remove as little as possible the underside) and soapy water or added to toothpaste. The detergent solutions are typically too aggressive for the prosthetic material and are not a satisfactory alternative to mechanical cleaning. The daily disinfection with chlorhexidine implants is only possible in cases of acute infections. Wearing night is not recommended if the patient does not have a prosthetic strict oral hygiene. |
maintenance prosthetic Control sessions, the practitioner carefully cleans the denture with a brush and appropriate curettes and then immersed in a few minutes cuveultrasonique (minimum power: 100 W). Disinfection of the prosthesis is provided by an antiseptic solution containing benzalkonium chloride (1 / 700) [6]. Prevention of candidiasisCertain clinical situations lead us to sail patients who may be exposed to Candida infection. This risk is increased in the case of flexible bases, because the proliferation of microorganisms (particularly yeasts) on the surface of this material is higher than that observed on hard bases [7]. Patients at risk are therefore subject to an ongoing clinical monitoring: • regular measurement of salivary pH, using indicators colored paper, is a diagnostic and a condition index of saliva. A significant decrease in pH will sign a breeding ground for yeast growth; • possibly mycological examination is performed with a removal and direct observation by light microscopy (staining or Gram-May-GunwaldGiem) or culture in the laboratory for analysis. |
|
The cons-indications Material characteristics and constraints on their use does not solve all problems. There are cons-specific guidance: • the asialie: often resulting in cancer treatment. Yet these are generally patients where the risk of osteoradionecrosis are important and which require rehabilitation with a flexible base. The practitioner will choose, if possible, a compromise using saliva substitutes. Over the years, often there is a small salivary secretion ... saving; • Poor hygiene may be the result of a motor disability or cerebral, but also neglect. The motivation for health and / or supported by a third party (family caregivers) can sometimes afford to undertake the completion of prosthetic treatment; • candidiasis: they should be treated, if possible, before the completion of the prosthesis and close monitoring should be ensured; • in maxillofacial prosthesis: flexible materials should never be in contact with the tissues Mobile (veil) or sinuses and nasal mucous membranes; • floating peaks can be addressed through these soft materials "permanent". |
Therefore, it is essential to emphasize the importance of oral hygiene prosthetic, monitoring and maintenance "The patient must be" informed "principally made aspects of this type of prosthetic treatment. conclusionOne can not ignore the fact that flexible bases are part intégrantede our armamentarium. They are often the only prosthetic solution for patients with anatomical defects and / or functional such that no surgery is possible. The indications for the use of flexible basis (regardless of the family of materials) show that the compromises are not an easy solution. Indeed, these materials can not in any way mitigate or compensate for an inadequate technique. On the other hand, the chemical nature of flexible bases, their surface, their binding to the rigid base, the aging phenomena ... are parameters that not only can not tolerate certain clinical situations, but we are now booking their use in the medium term. The patient will be clearly informed of the benefits but also the limits of this type of prosthetic restoration as well as constraints related to hygiene and maintenance. Only under these conditions that the patient and practitioner will find satisfaction in the realization of a complete denture lined with a flexible so-called "permanent". perspectivesThe bases do not fit soft tissue Mobile, which has two consequences: 1) they provide a peripheral seal of poor quality; |
2) their use is limited in maxillofacial prosthetics. We think it may be possible in future to improve their surface, but especially our research continues to use sector-based flexible. It was planned that the flexible material to areas requiring damping while keeping a peripheral seal rigid resin. ■ bibliographie 1 Louis JP, Archien C, Ludwigs H, Louis C. Les matériaux souples permanents en prothèse complète. Une solution intéressante : silicone Lutemoll vulcanisé sur base en titane pur. Actualités Odonto Stomatol 1992; 177:203-229. 2 Douz ER, Koran A, Craig RG. Physical property comparison of 11 soft denture lining materials as afunction of accelerated aging. J Prosthet Dent 1993;69(1 ): 114-119. 3 Montai S, Veyret D, Segura D, Martin R. Simulations informatiques du comportement des bases souples « permanentes » en prothèse totale. Cah Prothèse 1995;90:40-46. 4 Lejoyeux R. La réfection des bases en prothèse complète. Coll. « Guide clinique ». Paris : Éditions CdR 1995; (6): 81-87. 5 Buch D, Wehbi D, Roques-Carmes C. Solutions préventives anti-trauma utilisant des composés visco-élastiques comme matériaux de rebasage en prothèse amovible. J Biomat Den 1992;7:69-77. 6 Ettinger RL, Beck JD, Miller J, Jakobsen J. Evaluation of a fluoride rinse program in an institutionalized adult population [abstract], J Dent Res 1983;62:669. 7 Nikawa H, Iwanagia H, Kameda M, Hamada T. In vitro analysis of Candida albicans adherenceto soft denture lining materials. J Prosthet Dent 1992;68:804-808. |
SUMMARY The major indication for the use of a flexible so-called "permanent" as applied to denture patients in whom surgery is against inappropriate. These materials have the advantage of producing a shock and provide comfort. The realization of this type of treatment is subject to the same rules as the denture "classic". Any time a number of parameters are taken into account and we reserve the flexible materials for use in the medium term, consistent with the rules of hygiene and maintenance specific to these types of material: in these conditions, flexible bases can help find a solution and often the only clinical case sensitive.
Keywords complete denture, hygiene, shock-absorber, soft lining materials.
SUMMARY « Permanent » supple materials: what indications in full denture ?
The use of « permanent » supple materials in full denture allows a prosthetic rehabilitation of a whole category of partially ortotally-edentulous patients for whom any surgery is contraindicated (either momentarily or definitvely). These supple materials will play an important part of shock absorption and will bring much comfort by providing a better dispatching of constraints.However, the supple bases show a certain number of constraints linked to the very nature of these materials (link with the resinbase, surface state, ageing...). That is why we offer certain options aiming at reducing the impact of these parameters ; in particular, we give a preponderance to the oral prosthetic hygiene and to the maintenace without which nothing is possible. The patient must be enlightened about the advantages and limits of this type of prosthetic treatment. Currently, we recommend amedium-term use of these « permanent >> supple materials.
