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Flexible Dentures in Prosthodontics -An overview



There is evidence that Dentistry was practised as far back as 3000 B.C. in Egypt. Dentures are believed to be the mode of treatment for replacing missing teeth around 700 BC. Thereafter, a process began towards improvement in the quality of materials used for fabricating dentures, as the patients demanded better aesthetics, function and comfort. This review tracks the history of flexible materials used as a denture base to the present stage and point towards the research and development in the future. Hard and soft tissue undercuts are frequently encountered in the fabrication of prosthesis in partially as well as complete edentulous arches. This article is an effort to review the various commercially available flexible denture base materials and highlights their indications and special instructions in wearing and maintenance of the same.
Flexible Dentures in
Prosthodontics - An overview
Prafulla Thumati1, Padmaja S2, Raghavendra Reddy K3
There is evidence that Dentistry was practised as far back as
3000 B.C. in Egypt. Dentures are believed to be the mode of
treatment for replacing missing teeth around 700 BC.
Thereafter, a process began towards improvement in the quality
of materials used for fabricating dentures, as the patients
demanded better aesthetics, function and comfort. This review
tracks the history of flexible materials used as a denture base
to the present stage and point towards the research and
development in the future. Hard and soft tissue undercuts are
frequently encountered in the fabrication of prosthesis in
partially as well as complete edentulous arches. This article is
an effort to review the various commercially available flexible
denture base materials and highlights their indications and
special instructions in wearing and maintenance of the same.
Key words: Flexible dentures, undercuts, Acrylic clasps, Fibre-
reinforced resin
doi: 10.5866/2013.541380
1Professor, Department Head
2Senior Lecturer
Department of Prosthodontics,
Dayananda Sagar College of Dental Sciences,
Bangalore, Karnataka, India
3Senior Lecturer
Department of Prosthodontics
Sri Sai College of Dental Surgery,
Vikarabad, Andhra Pradesh, India
Article Info:
Received: July 8, 2013
Review Completed: August 10, 2013
Accepted: September 9, 2013
Available Online: February, 2014 (
© NAD, 2013 - All rights reserved
Email for correspondence:
Quick Response Code
Flexible dentures are custom-made dental installations that rely on unique products to achieve a less
rigid design. These new kinds of dentures are popular for those who struggle with the conventional acrylic
base of dentures that may wear, irritate the gums, induce allergic reactions or generally fail to provide a
comfortable result. Dentists and their patients are often interested in what these newer and more versatile
products can do to better outfit those with a history of tooth decay (Fig. 1 and 2) or who need dental prosthesis
to function or who want to avoid the discomfort due to the rigidity of the denture base.
Journal homepage: www. nacd. in
Indian J Dent Adv 2013; 5(4): 1380-1385
Polymerization shrinkage encountered in
conventionally cured Poly(methyl methacrylate) led
to the development of a special injection-molding
technique. Initially developed as a Fluoropolymer
(1962), Acetal began to be used in 1971. The material
used nowadays is Nylon based plastic (Polyamide).
Elastomeric resins can be added to resin polymer
formulas to create greater flexibility and can be
strengthened with glass fibres.1 Unique features-the
semi-crystalline nylon composition provides
strength, flexibility, transparency, high impact
resistance, colour stability, high creep resistance,
high fatigue endurance, excellent wear
characteristics, good solvent resistance, no porosity,
no biological material build up or odours or stains,
low water sorption and good dimensional stability,
monomer and metal free and the microcrystalline
structure is easy to finish and polish like acrylic.
An alternative denture prosthesis design in
which optimal flange height and thickness can be
achieved is by using flexible denture base material.2
Soft dentures are an excellent alternative to
traditional hard-fitted dentures. Traditionally
relining dentures with a soft base increases comfort
at the cost of chewing efficiency. To make up for the
loss of chewing efficiency, denture wearers would
use denture adhesive, which has its own problems.
A flexible material is now an option that does
not trade off the ability to eat. Flexible denture (soft
dentures) are generally used when traditional
dentures cause discomfort to the patient that cannot
be solved through relining.3 Soft dentures are not
the same as a soft reline for traditional dentures.
Soft relines use a soft putty-like substance to
separate gums from the hard acrylic in dentures.
Flexible dentures use a special flexible resin that
prevents them from chafing the gums, allows the
wearer to chew properly. It also provides a soft base
that prevents the gums from being rubbed raw.
Some of the commercially available products are
Valplast, Duraflex, Flexite, Proflex, Lucitone,
Flexible dentures have got various advantages
over the traditional rigid denture bases.
Translucency of the material picks up underlying
tissue tones, making it almost impossible to detect
in the mouth. No clasping is visible on tooth surfaces
(when used in manufacturing of clear clasps)
improving aesthetics. The material is exceptionally
strong and flexible. Free movement is allowed by
the overall flexibility. Complete biocompatibility is
achieved because the material is free of monomer
and metal, these being the principle causes of
allergic reactions in conventional denture and
partial techniques. Flexible dentures will not cause
sore spots as seen with rigid acrylic resins. Flexible
dentures may be used as an alternative treatment
plan in rehabilitating the anomalies such as
Ectodermal dysplasia.
It is nearly unbreakable, pink coloured like the
gums, can be built quite thin, and can form both the
denture base and the clasps as well. The clasps are
built to curl around the necks of the teeth and they
are practically indistinguishable from the gums that
normally surround the teeth due to its Opalescence.
This type of partial denture is extremely stable and
retentive, and the elasticity of the flexible plastic
clasps keeps them that way indefinitely. It has
superior aesthetics, no metallic taste and is non-
allergic. Free movement is allowed by the overall
flexibility and can, therefore, be referred to as “a
built in stress breaker”. Long term health of tissues
and teeth is maintained due to their gentle
massaging action without adversely loading
Extreme caution is necessary when processing
to avoid skin contact with the heated sleeve,
cartridge, furnace, heating bay, hot cartridge,
injection insert, piston head adapter, hot flasks and
heat lamps. They do discolour due to sorption.
Full dentures, partial dentures, Bases and
relines, in cases with bilateral in-operable undercuts
when pre-prosthetic surgery is contraindicated.
Special applications- for TMJ splints, for the
patients allergic to acrylic monomers, as cosmetic
Flexible Dentures in Prosthodontics - An overview Prafulla Thumati, et, al.
Indian J Dent Adv 2013; 5(4): 1380-1385
veneers/gum veneers to mask gingival recession
(Fig. 3), in periodontally involved teeth, sensitive
teeth, cancerous mouths or other conditions in which
the teeth are compromised, treatments involving
high torus or cleft palate conditions, as mouth
guards in sports, Bruxisum splints/ Night guards,
Bite splints, Space maintainer, Paediatric cases,
Obturators, Speech therapy appliances and
orthodontic retainers.4
The Flexible dentures in combination with cast
partial framework:
This combination eliminates most of the
difficulty of recurrent sore spots, since the
framework resists movement and pressure from the
clasps, while having the benefit of nearly invisible,
gum coloured clasps (Fig. 4 and 5). It also has the
advantage of being tooth supported.
Flexibility is not an advantage where there are
no undercuts in a complete denture situation, as the
retentive peripheral seal can be broken in function.
It is difficult to use with less inter-ridge space, as
bulk of the tooth is needed for mechanical retention.
Denture is placed in very hot water (150 degree
F) for a minute prior to insertion and allowed to
cool to tolerable temperature. This makes the partial
as flexible as it would be at body temperature.
Grinding is done as a last resort at a low speed of
around 250-300 rpm using green stones.
Unilateral or bilateral undercuts are frequently
encountered and may complicate successful
fabrication of denture prosthesis.5,6 Management of
these situations conventionally includes alteration
of the denture bearing area, adaptation of the
denture base; careful planning of the path of
insertion and the use of resilient lining material,
and this can be sorted using a flexible material.
Pro-flex is the flexible denture base material
which can be used for Full & Partial flexible denture.
Pickett Dental Laboratory has been offering pro-flex
full and partial flexible dentures since 1998. Pro-
flex is easy to work with the quality, aesthetics and
most importantly the final results. Pro-flex denture
material may be indicated in some of the anatomical
considerations where tooth and tissue undercuts are
a hindrance. It enables the material to effectively
engage those undercuts. Also pro-flex being hypo-
allergenic is recommended for patients with known
acrylic or metal sensitivities. Aesthetically the
material is semi-translucent, allowing the prosthetic
to better blend with the colour of the natural gum
tissue. With pro-flex flexible partials, there are no
metal clasps. Pro-flex full and partial flexible
dentures are easily adjusted by the dentist.
Valplast is a flexible denture base resin that is
ideal for partial dentures and unilateral
restorations. The resin is a biocompatible nylon
thermoplastic with unique physical and aesthetic
properties that provides unlimited design versatility
and eliminates the concern about acrylic allergies.
The valplast flexible partial allows the restoration
to adapt to the constant movement and flexibility
in the mouth (Fig. 6,7,8 and 9). The flexibility
combined with the strength and light weight,
provides total comfort and great looks. The valplast
partial is virtually invisible because there are no
metal clasps and the material itself blends with the
tissue in the mouth. Valplast flexible dentures can
be indicated in case of patients who have acrylic
allergies, history of partial frame breakage,
alternative to implants or fixed prosthesis and
presence of tori.
The sunflex flexible denture base materials are
virtually invisible, unbreakable, metal-free, light
weight and incredibly comfortable. They are made
from a strong biocompatible nylon thermoplastic
The sunflex flexible denture base materials are
exclusively used in partially edentulous arches
because of its versatile advantages such as-
Flexible Dentures in Prosthodontics - An overview Prafulla Thumati, et, al.
Indian J Dent Adv 2013; 5(4): 1380-1385
No need of metal clasps-only tissue colored
clasps that blend with natural teeth
More stain-resistant than other flexible acrylics
Has the perfect degree of flexibility
Can be relined and repaired
Will not warp or become brittle
Stands aesthetically superior removable partial
with full functionality and comfort
Ideal for patients considering a removable
partial and those who do not want metal clasps
Are perfect for patients who are allergic to
Unbreakable Flexite Plus Dentures:
Flexible dentures created a great deal of
excitement when they were first launched. No more
ugly metal wires, no more broken dentures. What’s
more, the denture can be bent or even twisted, it
springs right back into its original shape. Flexite
Plus is material of choice for all removable partial
dentures. Unlike their predecessors which were
flexible throughout and create problems when they
are long-span, the new material is selectively flexible
and shows rigidity when due.
The biggest advantage of this sort of dentures
is that unlike the hybrid dentures, they are
unbreakable (Fig. 10 and 11) like the former fully
flexible denture systems. Like their fully flexible
predecessors, they also donot have the unsightly
clasps seen in chrome dentures. Flexite Plus is pink
in colour. Flexite Plus plates are not flexible. This
makes them capable of supporting chewing forces
in long-span dentures. Another possibility with
Flexite Plus is the very tiny sectional denture (Fig.
12 and 13). Without the plate covering the entire
roof of the mouth, these dentures tend to be more
Below is another example of a Flexite Plus
denture. It is a sectional prosthesis that shows
remarkably good retention and stability. This was
only a temporary denture which the patient used
while the patient waited for the implant to integrate.
No prosthesis beats an implant restoration in terms
of function.
Above are 2 dentures belonging to the same
patient. On the left is old acrylic denture with metal
clasps (Fig. 14 a), which has cracked a few times
when the patient dropped it. The new denture on
the right uses Flexite clasps which are pink in colour,
which will not break when dropped (Fig. 14 b).
Flexible dentures help the patients to avoid
some kind of pain associated with the old style
denture models. A flexible resin coating allows for a
custom fit, with hard synthetic teeth still imbedded
in the design to help with chewing food. Flexible
dentures help achieve greater stability and comfort.
Those who have found, for example, that even the
simple back and forth action of chewing causes gum
pain with traditional dentures may be able to find
relief in new and more precise fitting flexible
varieties of denture products.
In addition to these benefits, flexible dentures
are also designed to be porous and to “breathe” better
than some other kinds of dentures. This helps
prevent the build up of bacteria on the dentures and
is another reason that these innovative denture
products are so popular.
The fabrication of the optimum restoration is
depending on the clinician’s skill in selection of the
type of the restorations which is required for the
patient. The fabrication of prosthesis for the
partially edentulous arches encountered a special
challenge where many interferences, various path
of placement, tilted teeth and deranged occlusion
will complicate the treatment plan. Flexible
dentures will stand in a superior position in fulfilling
the various patients demand for more retentive and
aesthetic treatment needs. Flexible dentures were
previously selected by few patients and the clinician
but nowadays it has become an elective treatment
option. No more ugly metal wires. No more broken
Flexible Dentures in Prosthodontics - An overview Prafulla Thumati, et, al.
Indian J Dent Adv 2013; 5(4): 1380-1385
Figure 1: Cast partial denture
Figure 2: Decayed abutments
Figure 3: Cosmetic veneer masking gingival
Figure 4: Combination of flexible and metal in framework in situ
Figure 5: Combination of flexible and metal framework
Figure 6: Valplast RPD showing thickness and clasps of same material
Figure 7: Valplast RPD on cast
Figure 8: Valplast RPD in mouth
Flexible Dentures in Prosthodontics - An overview Prafulla Thumati, et, al.
Indian J Dent Adv 2013; 5(4): 1380-1385
Figure 9: Valplast RPD in mouth
Figure 10: Unbreakable Flexite Plus Dentures
Figure 11: Unbreakable Flexite Plus Dentures showing its
Figure 12: Flexite plus
sectional partial
Figure 14 a: Old acrylic denture
Figure 14 b: Flexite denture
Figure 13: Flexite plus sectional
partial denture with good retention
1. Lowe LG. Flexible denture flanges for patients exhibiting
undercut tuberosities and reduced width of the buccal
vestibule: a clinical report. J Prosthet Dent 2004;92(2):128-
2. Naylor WP, Manor RC. Fabrication of a Flexible prosthesis
for the edentulous scleroderma patient with microstomia. J
Prosthet Dent 1983;50(4):536-538.
3. Antonelli JR, Hottel TL. The “ Flexible augmented flange
technique” for fabricating complete denture record bases.
Quintessence 2001;32(5):361-364.
4. William J. O’Brien. Dental materials and their selection.
Third edition, Quintessence Publishing co. 2002..
5. Anusavice KJ. Phillips’science of dental materials. 10th ed.
Philadelphia(PA):WB Saunders; 1996. p. 237-271.
6. Blagojevic V, Murphy VM. Microwave polymerization of
denture base materials. A comparative study. J Oral Rehabil
Flexible Dentures in Prosthodontics - An overview Prafulla Thumati, et, al.
Indian J Dent Adv 2013; 5(4): 1380-1385
... Free movement is allowed by the overall flexibility and can, therefore, be referred to as "a builtin stress breaker". 5 Patients usually come to our clinics to restore their lost teeth. However, the purpose of denture construction should not be restricted to tooth replacement but should maintain the surrounding tissue health (6) . ...
... Also, the results illustrated that Q9 had the least response rate, which indicates the material the flexible denture made of, only 22 respondents knew that it was made of nylon. 5 The number of respondents who correctly answered Q16, Q19, Q22 and they knew that flexible dentures are contraindicated in patients with limited mouth opening, lingual tori, and knife-edge ridges were 60, 56, and 46 respectively. While the questions Q11, Q13, Q17, Q18, Q20 reflected the awareness towards indications of the flexible denture as 80 respondents knew that it is an option in the treatment plan of patients with ectodermal dysplasia, and more than half they aware that it is indicated for patients with teeth or tissue undercuts, patients with a history of repeated denture fracture and is considered as an alternative for patients those are allergic to acrylic dentures. ...
... 6,14 Questions Q8, Q10, Q14, Q23, Q24, and Q25 analyzed the attitude of the respondents towards the advantages of the flexible denture, as more than half they knew that it is unbreakable, it needs minimum or no mouth preparation, it provides more stability during mastication 4, 5, 14 as being reported by Thakral et al. 15 and Sharma et al., 16 it more cosmetic and lighter in weight compared to acrylic denture 14 as being agreed by Shamnur et al. 17 while the number of them who aware that flexible denture doesn`t displace soft tissues during function was only sixty-eight. 4,5,14 Responses to the questions Q12, Q26, Q27, Q29 revealed that more than half of the respondents were aware that good oral hygiene is very important, and as there was no addition that could be made onto nylon a flexible denture is not easy to repair. 6,9 While only 31.2% knew that staining of a flexible denture by various ingredients of food, tea and coffee is likely to happen, and 68.8% agreed that the cost factor plays a role in the patient`s decision to make a flexible denture rather than an acrylic one. ...
Full-text available
Background: Management of partially edentulous patients with hard and soft tissue undercuts is complicated, and the use of flexible dentures for these cases offers dual advantages of aesthetics and flexibility. However, research shows a varying preference for flexible dentures among general dental practitioners, prosthodontists, and other dental specialties. Objectives: The aim of this study was to survey the attitude and awareness of a sample of Libyan dental clinicians towards advantages, disadvantages, indications, and contraindications of flexible dentures. Material and methods: A descriptive cross-sectional study was conducted among 250 dentists currently practicing in different cities of Libya. Only 218 dentists responded. Using Google form software, a self-administrable e-questionnaire consisting of thirty-one multiple choice questions with "yes," "no" or "not sure" answers encompassing major aspects of flexible dentures was conducted through an online survey. Results: Out of 250 Libyan dentists to whom the questionnaire was sent, only 218 dentists responded and our results revealed that the respondents were females more than males with a ratio (2:1) and more than half of them were of age group (35-60 years) work in governmental dental practice with more than ten years of experience and 34.9% of them prefer and often offer flexible dentures to their patients. The majority of respondents with a long-term success of the flexible denture were prosthodontists who had more than ten years of experience with a correct response rate of more than 50% of questions that reflected their attitude and knowledge. Conclusions: Despite the fact that flexible dentures are not taught in Libyan universities of dentistry, about more than one-third of respondents prefer and recommend this treatment to their patients, and the long-term success of these prostheses was dependent on clinicians' education and their clinical experience.
... Introduction of flexible dentures was in the late 1940s had the vision to experiment with the new polymers of the day (Nylon). (7)(8)(9) Aesthetic Consideration in Clasp Retained (RPD): ...
... However, the use of such RPDs can seriously affect various tissues because of their low rigidity. (5)(6)(7)(8)(9)(10)(11)(12)(13)(14) Nagakura, et al. (15) fabricated high rigidity glass fiber-reinforced thermoplastics (GFRTPs) for use in RPDs, examined their physical properties such as apparent dentistry, dynamic hardness and, flexural properties. They concluded that GFRTPs have beneficial effects because of their better physical properties. ...
... Even if there is a slight shifting of the remaining teeth over time, the flexibility of the denture material, allows the use of prosthesis with little adjustment. (7,10,40) Rebasing (Changing the entire plastic/tissue area) is possible. So, can be made thinner than traditional acrylic dentures and will not wrap or become brittle. ...
Full-text available
Abstract Background: Clasp materials play a critical role in overall aesthetic outcomes of removable partial dentures. The long-term maintenance of these outcomes depends on color stability of these materials. Staining of prosthodontics materials may result in patient dissatisfaction and additional expense for replacement. Purpose: The purpose of this in vitro study was to evaluate the effect of various commonly consumed beverages on the color stability of Acetal resin and Polyamide clasps when being polished or left non-polished. Materials and methods: A normative class IV Kennedy partially edentulous maxillary heat cure acrylic resin model was chosen, duplicated to obtain the stone master casts. 8 Acetal resin RPDs and 8 Polyamide RPDs were constructed and finished. A mechanical polishing was performed for the ten left clasps of Acetal resin and Polyamide RPDs while leaving the right ones to be non-polished. Before immersion, both clasps were analyzed for color characteristics against a gray background with A3 using a spectrophotometer. They were immersed in four beverages media (tea, coffee, cola, and orange juice).The Specimens were removed at 1, 7, and 28 days respectively, desiccated, and analyzed by the spectrophotometer. Results :The results reported statistically significant differences between polished and non-polished clasps for beverage solutions of the study . Comparison between the polished left (polyamide and acetal) with respect to the L (lightness) parameter, the results elaborated statistical significant higher mean values among acetal than polyamide group (P=<0.001*), (P=<0.001*), (P=0.003*) and, (P=0.004*) respectively. iv Conclusion Within the limitation of this study, it can be concluded that: Acetal resin exhibited high color changes in comparison to the polyamide clasps. The color changes of Acetal resin constantly increased with the immersion time. Polishing procedures essentially improve the color stability of Acetal resins clasps when being immersed in commonly consumed beverages.
... Polymerization shrinkage encountered in conventionally heat cured Poly (methyl methacrylate) led to the development of a special injection-molding technique. 2 Flexible dentures are fabricated by this technique and are used to replace one or more missing teeth either in the upper or lower jaw. There are various advantages of nylon dentures which are unique: ultra-thin, light, very flexible and virtually unbreakable. ...
Full-text available
Partially edentulous patients need treatment to restore missing teeth and surrounding structures. Partial dentures are mode of treatment for replacing some of the missing teeth in either arch. Partial dentures are made of variety of materials. Some are made of only acrylic material and some are metal framework with acrylic extensions to replace missing teeth. Recently flexible materials are in use to fabricate tooth supported prosthesis. These materials has advantage over conventional metal and acrylic dentures as there is no metal clasp around the tooth, they are more retentive giving life like prosthesis and are translucent by which they match the color of underlying mucosa. It is seen that patient acceptance is more for flexible partial dentures as they are less likely to cause mucosal irritation and pain.
... [6][7][8][9] Most frequent complaints complain encountered by patient wearing denture made from acrylic resin denture are mucosal irritation, allergic reaction, insufficient retention and stability, food accumulation under denture, difficulties in speech, mastication, unattractive appearance, fracture and Debonding of teeth. [10][11] Numerous patients find acrylic and metal dental replacement awkward on the grounds that it applies tension on fundamental delicate tissue causing torment and distress. Other fined that metal clasping as an aesthetic concern. ...
Full-text available
Aim: This study was conducted to evaluate the patient overall experience and problems encounter in use of conventional and FD base material. Materials and Method: The study comprises of randomly selected 54 partially edentulous patients (male or female) reported to the Department of Prosthodontic. The nature of the study was explained and informs consent was taken. The conventional denture is made of polymethyl-methacrylate, Valplast and Flexite were two nylon denture base materials utilized in complete 54 cases were given the imperative prostheses. Results: There were total no of 54 cases were taken. All off the cases were evaluated on basis of halitosis, mucosal irritation, ease of insertion and removal, functional comfort and fracture/crack frequency. As per the questioner, the result was compiled and data were analysed by, Wilcoxon signed ranks test to study the change in various indices of functional observations and to draw the conclusion. Out of 54 cases only 6 cases were reported with halitosis, 0 cases reported with the difficulty in removing and insertion of denture, 3 cases reported with mucosal irritation and 12 cases reported with Debonding of teeth after 8 to 9 months, respectively.
... Additionally; with grinding this prosthesis, masks, proper ventilation, and vacuum systems should be used. Extreme caution is obligatory when processing this materials to avoid skin contact with the heated sleeve, cartridge, and furnace, heating bay, hot cartridge, injection insert, piston head adapter, hot flasks, and heat lamps [106]. ...
Full-text available
The idea of traditional tooth-retained overdentures is cost effective and simple treatment modality than implant overdentures treatment. When a small number of firm natural teeth are present in other respects compromised dentition, these teeth can be retained and utilized as overdenture abutments teeth. This aids to enhance the stability and retention of the definitive prosthesis. The utilization of thermo-elastic acrylic resin denture base in the fabrication of mandibular overdenture leads to improvement of denture retention.
... At the acrylic partial dentures, the clasps are modeled with pliers from wire, while in the case of a flexible denture base; the clasps represent extensions of the flexible denture bases. The clasps can be adjusted by bending with the plier, in order to increase or decrease the retention (figure 1.C) [11,12]. Flexible partial dentures processed with the pressing procedure provides good retention and good aesthetic [13]. ...
Full-text available
Introduction: At present, the researchers are targeted to improve and increase the biocompatibility of dental materials that are in direct contact with biological tissues. The biocompatibility of the dental materials that contact the tissues of the oral cavity present relevance for the patient, clinician, dental technician, and manufacturer. Aim of the study: The aim of this study was represented by the comparative research regarding the comfort of the patients wearing removable partial prostheses with clasps made of wire and flexible polymers. Material and Methods. Patients wearing partial dentures from Meliodent heat-cured acrylic resins with wipla wire clasps, flexible partial dentures made from Valplast and dentures with clasps of CuSil silicone rubber participated in this study. The research was performed on 3 groups, of 8 patients each, in which comfort levels (according to 5 criteria) were determined, after 6, 12, 18, respectively 24 months of the partial removable prostheses insertion in the oral cavity. Results. Presence of decubitus lesions of the oral mucosa in the clasps areas was noticed mostly in the Valplast polyamide dentures (37.5%), existence of color changes at the base of prostheses and of clasps area appeared in 37.5% of the third group (CuSil PAD) patients, no patient included in the study presented allergic reactions and at the third and fourth recall, only 1 patient of all groups complained of unpleasant taste in the oral cavity. Conclusion. The removable prosthetic restorations with clasps made of flexible polymers and CuSil gaskets of silicone rubber, although initially much more comfortable and therefore much better accepted by patients, after two years were no longer active, could not be activated and necessited technical restorations, compared to those made of wipla wire clasps, which were activated with pliers, or, in the case of fracture, were replaced by the technician in the dental laboratory.
... (12,13) A thermoplastic Acetal resin is a biocompatible material so can use with patient allergic to Co-Cr alloys and have good physical properties make it suitable for construction of removable partial dentures (14)(15)(16) . It is reported to have a sufficiently high resilience andmodulus of elasticity to allow its use in the manufacture ofretentive clasps (17- 19) , connectors, and support elements for removable partial denture. Also, Acetal resin is also strong, resistsfracturing, and is flexible so, does not wear during occlusal forces and consequently will maintain vertical dimension Over long periods of time (20)(21)(22) . ...
... Fibers are easier to incorporate in resin matrix and exhibit good bonding if treated with a coupling agent. Fibers reinforcement is dependent on many variables like type of ibers, percentage in matrix, modulus and distribution of ibers, length, orientation, and form [7]. The present study was conducted to assess effect of cigarette smoking on different denture base material. ...
Full-text available
Aim: Denture base materials were subjected to cigarette smoke for the purpose of determining their surface roughness. Materials and Methods: Polymethylmethacrylate and flexible denture base materials were used to manufacture 40 specimens for this study (20 for each). Each sample was randomly assigned to one of four groups: control, flexible, and heat-cured denture base material samples. The heat-cured denture material samples were the only ones that had been exposed to cigarette smoke (subgroup III). There was a control group for each group. For the smoke test groups, distilled water was utilised, whereas cigarette smoking was used for the water test groups. Each participant in the trial was exposed to six cigarettes in a specially created smoking area. Surface roughness differences between pre- and post-smoking samples were analysed using a profilometer. The data was analysed using a paired comparison and an independent comparison. Groupings differed significantly in their initial roughness and final roughness, according to results from a paired t-test. Conclusion: Surface harshness of tobacco-smoke-exposed specimens of both the intensity-restored and the adaptive dental replacement base materials was greater.
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Review on flexible dentures which is in popular use
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A technique for fabricating complete denture record bases that features flanges augmented with resilient liner is reintroduced and recommended. It is coined the "flexible augmented flange technique." The technique takes advantage of the elastic properties of tissue conditioner, available anatomic undercuts in definitive casts, and the rigidity of record base resin to create stable, retentive, well-fitting, and comfortable record bases that minimally abrade casts. Tissue conditioner, which strongly bonds to the intaglio surface of record base flanges, replaces blockout wax to form augmented flanges with flexible inner sections that are sufficiently elastic to engage and then release from undercuts. The flexibility of the inner section of the flanges permits atraumatic insertion and removal from a patient's mouth, despite overall record base rigidity. Accurate, verifiable, maxillomandibular jaw relation records can be obtained with the flexible augmented flange technique.
Buccal undercut of the maxillary tuberosity together with reduced width of the buccal vestibule can complicate denture fabrication. This clinical report describes the treatment options for this situation, the rationale for the design and use of flexible denture flanges in the maxillary posterior buccal vestibule, and the laboratory procedure for incorporation of flexible denture flanges in the undercut area.
The exercise prosthesis serves as an interim device to achieve an increased opening of the jaws. Once the patient is able to insert the existing denture or when an impression tray can be placed in the patient's mouth without extreme discomfort, its purpose will have been achieved; the dentures should be relined or remade. Some patients need only achieve slight increases in the maximal vertical oral opening to make prosthetic treatment possible (Fig. 6). While this technique is useful for the edentulous scleroderma patient, it may have application for individuals with limited mouth opening secondary to facial burns or other scarring. It is suggested as an alternative to surgical correction through bilateral commissurotomies.
A comparison of some properties of denture base polymers processed by both microwave and water-bath methods demonstrated that, in general, water-bath polymerization with a long curing cycle and a 3-h terminal boil produced superior properties. Although these two methods were inter-changeable for the conventionally heat cured material, consistently superior results were produced by following the method recommended by the manufacturer. Microwaving of autopolymerizing resin improved mechanical properties and reduced residual monomer. The clinical significance of these results remains to be tested.
Phillips'science of dental materials
  • K J Anusavice
Anusavice KJ. Phillips'science of dental materials. 10th ed. Philadelphia(PA):WB Saunders; 1996. p. 237-271.