Uso de prótesis parcial removible con resina acrílica termoplástica: una revisión de literatura

La prótesis parcial removible (PPR) es una alternativa de tratamiento en pacientes que perdieron algunos elementos dentarios, debido al costo relativamente bajo y a la generación de una función masticatoria satisfactoria. Además, es una buena opción cuando hay pérdida de los tejidos óseos, dado que impide la instalación de implantes dentarios. La PPR convencional presenta una estructura metálica que ofrece retención y resistencia a la prótesis, convirtiéndola en poco agradable a los pacientes, por el hecho de dejar a la vista el metal en la cavidad oral. A partir de investigadores que decidieron ir más allá del simple estudio de la función y la estética de las PPR para adentrase en sus diversas formas de presentación, surgió la prótesis parcial flexible (PFlex). La PFlex es una prótesis parcial confeccionada con resina termoplástica, sin metal y con flexibilidad. Si bien, muchos profesionales la emplean como prótesis temporal, otros tantos la han usado como alternativa a la PPR convencional. Así, uno de los frecuentes interrogantes de los clínicos es si realmente es posible utilizar la PFlex como alternativa protética definitiva. Por tanto, el propósito de este trabajo fue realizar una revisión de la literatura para evaluar si el uso de prótesis parciales removibles con resina termoplástica puede ser una alternativa a las prótesis parciales convencionales, exponiendo las ventajas, desventajas, indicaciones, contraindicaciones y las propiedades del material protético.

Removable partial denture (RPP) is an alternative treatment when it comes to patients who have lost some dental elements, as they have the advantages of a relatively low cost and a satisfactory masticatory function. Furthermore, it is a good option when there is bone tissue loss, making dental implants placement unfeasible. Conventional PPR has a metallic frame that provides retention and resistance to the prosthesis, which makes it unpalatable to patients because it leaves the metal in the oral cavity evident. Many researchers, aiming to give back beyond function and aesthetics, are studying forms of presentation of PPR, thus emerging the flexible partial prosthesis (PFlex). PFlex is a partial denture made with thermoplastic, resin metal-free and with flexibility, however its use, for many professionals, is limited only as temporary prostheses, but there are some clinicians who use PFlex as an alternative to conventional PPR. Thus, one of the questions constantly asked by scientists is whether it is possible to use PFlex as a definitive prosthetic alternative. Therefore, the aim of this study was to conduct a literature review to assess whether the use of removable partial dentures with thermoplastic resin can be an alternative to conventional partial dentures, exposing the advantages, disadvantages, indications, contraindications, and the properties of the prosthetic material.

Comparative study of some mechanical properties of cobalt chromium and polyether ether ketone thermoplastic removable partial denture clasps: an In-vitro Study / Estudo comparativo de algumas propriedades mecânicas dos grampos parciais removíveis termoplásticos removíveis termoplásticos de cobalto cromo e éter cetona: um estudo in vitro

Objective: was to evaluate the retentive force, fatigue resistance and deformity of clasps made from two materials cobalt chromium and poly ether ether ketone (PEEK). Material and Methods: sixteen models were fabricated,each one having lower 1st molar. Models were divided into two groups according to materials,group I (GI) for cobalt chromium (Co-Cr) and group II (GII) for PEEK. Each testing models and its clasps were mounted inside universal testing machine, the retention was measured by applying withdrawal force to it by this machine at 5 mm/min. The Fatigue resistance is measured by the reduction in retention through repeated insertion and removal cycles using robota chewing simulator. Removal and insertion cycling of clasps was carried out for 360, 730, 1080, 1,440, 2,116 and 2,880 cycles (corresponding to 3, 6, 9, 12, 18 and 24 months of simulated clinical use of a RPD) to simulate the fatigue resistance test. Deformity was measured before and after each cycling using a digital micrometer. Statistical analysis was done by 2-way-ANOVA test to detect significance effects of each variable. Results: Retention and fatigue resistance, after 360, 730, 1080, 1,440, 2,116 and 2,880 cycles totally the difference between Co-Cr and PEEK groups was statistically non-significant (P = 0.0980> 0.05) where (Co-Cr > PEEK). Deformation results, regardless to evaluation time, Co-Cr group recorded statistically significant higher deformation mean value than PEEK group (P = 0.008 < 0.05).Regardless to material group, deformation mean value changed nonsignificantly by time (P = 0.2882> 0.05). Conclusion: PEEK clasps (1.0 mm in cross section diameter) engage 0.50 mm undercut provide sufficient retention nearly similar that of Co-Cr clasps.(AU)

Objetivo: o objetivo foi avaliar a força de retenção, a resistência à fadiga e a deformidade dos grampos fabricados com dois materiais diferentes: cromo-cobalto (Co-Cr) e poliéter-éter-étercetona (PEEK). Materiais e métodos: dezesseis modelos foram confeccionados, cada um com 1º molar inferior. Os modelos foram divididos em dois grupos de acordo com o material: grupo I Co-Cr e grupo II para PEEK. Cada modelo de teste universal e seus grampos foram montados em uma máquina de teste universal. A retenção foi medida aplicando força de retirada por esta máquina a 5 mm/min. A resistência à fadiga foi medida pela redução na retenção através de ciclos repetidos de inserção e remoção usando um simulador do ciclo de mastigação. O ciclo de remoção e inserção dos grampos foi realizado por 360, 730, 1080, 1.440, 2.116 e 2.880 ciclos (correspondendo a 3, 6, 9, 12, 18 e 24 meses de uso clínico simulado de um RPD) para simular o teste de resistência à fadiga. A deformidade foi medida antes e após cada ciclo, usando um micrômetro digital. A análise estatística foi realizada pelo teste ANOVA de 2 fatores para detectar os efeitos de significância de cada variável. Resultados: A retenção e a resistência à fadiga após 360, 730, 1080, 1.440, 2.116 e 2.880 ciclos entre os grupos Co-Cr e PEEK não mostrou diferença estatisticamente significativa (p = 0,0980> 0,05), onde (Co-Cr> PEEK). Para os resultados da deformação, independentemente do tempo de avaliação, o grupo Co-Cr registrou um valor médio de deformação maior, com diferença estatística significativa, quando comparado com o grupo PEEK (p= 0,008 < 0,05). Independentemente do grupo de material, o valor médio da deformação foi alterado de forma não significativa pelo tempo (p= 0,2882> 0,05). Conclusão: os grampos PEEK (1,0 mm de diâmetro da seção transversal) engatam 0,50 mm retenção quase semelhante à dos grampos Co-Cr (AU)

Effects of relining materials on the flexural strength of relined thermoplastic denture base resins

PURPOSE: The aim of this study was to evaluate the effects of relining materials on the flexural strength of relined thermoplastic denture base resins (TDBRs). MATERIALS AND METHODS: For shear bond strength testing, 120 specimens were fabricated using four TDBRs (EstheShot-Bright, Acrytone, Valplast, Weldenz) that were bonded with three autopolymerizing denture relining resins (ADRRs: Vertex Self-Curing, Tokuyama Rebase, Ufi Gel Hard) with a bond area of 6.0 mm in diameter and were assigned to each group (n=10). For flexural strength testing, 120 specimens measuring 64.0×10.0×3.3 mm (ISO-1567:1999) were fabricated using four TDBRs and three ADRRs and were assigned to each group (n=10). The thickness of the specimens measured 2.0 mm of TDBR and 1.3 mm of ADRR. Forty specimens using four TDBRs and 30 specimens using ADRRs served as the control. All specimens were tested on a universal testing machine. For statistical analysis, Analysis of variance (ANOVA) with Tukey's test as post hoc and Spearman's correlation coefficient analysis (P=.05) were performed. RESULTS: Acry-Tone showed the highest shear bond strength, while Weldenz demonstrated the lowest bond strength between TDBR and ADRRs compared to other groups. EstheShot-Bright exhibited the highest flexural strength, while Weldenz showed the lowest flexural strength. Relined EstheShot-Bright demonstrated the highest flexural strength and relined Weldenz exhibited the lowest flexural strength (P < .05). Flexural strength of TDBRs (P=.001) and shear bond strength (P=.013) exhibited a positive correlation with the flexural strength of relined TDBRs. CONCLUSION: The flexural strength of relined TDBRs was affected by the flexural strength of the original denture base resins and bond strength between denture base resins and relining materials.

Fabrication of palatal lift prosthesis using thermoplastic resin for a patient with velopharyngeal insufficiency / 대한치과보철학회지

Recently, flexible removable prosthesis with thermoplastic resin clasp has increasingly become popular. In comparison with conventionally used acrylic resin, thermoplastic resin has lower flexural strength and elastic modulus. Thus, flexible removable prosthesis has low risk of fracture, so denture base can be made thin and light, increasing patient comfort. Also, it can passively sit at tooth undercut during rest, so abutment teeth need minimum or no preparation. In this case report, a 44 year old female patient with mild velopharyngeal insufficiency was treated with a palatal lift prosthesis made of polyester thermoplastic resin. Since the patient had no missing tooth and desired conservative treatment, the flexible removable prosthesis provided relatively satisfactory results.

Flexible resins in the rehabilitation of maxillectomy patient.

Surgical resection is an established and common method for treatment of maxillofacial tumors. Such intervening surgery in this region may involve the destruction of antral, nasal, or orbital contents and jaws. Normally, the end result is a defect which may affect speech, swallowing, mastication and facial appearance. Prosthodontic restoration of functions and facial form is an excellent method in the replacement of missing parts and restoration of contour. Pertinent research in materials, designs and methods have resulted in whole array of possible prosthess that can be provided to meet specific patient needs. This case report describes the fabrication of definitive obturator prosthesis made of flexible acrylic resin on a chrome cobalt base.

A Study on the Bond Strength of Reline Resin to Pressure Injection Type Thermoplastic Denture Base Resin / 대한치과보철학회지

The purpose of this study was to evaluate the bond strength of reline resin to pressure injection type thermoplastic denture base resin.The denture base resins used in this study were Hipolycarbonate(High Dental Co.,Japan),Acetal dental(Pressingdental s.r.l.,Repubblica di San Marino)of thermoplastic resin and Acron MC(GC Dental Industrial Co.,Japan)of heatcured resin.The reline resins used were Lucitone 199(Dentsply international Inc.,USA),Tokuso rebase(Tokuyama Corp.,Japan),and Lightdon-U(Dreve-Dentamid-Gmbh,Germany).The reline resins are representative of heat-cured,self-cured,and light-cured resin respectively.Bond strength was examined by use of a three-point transverse flexural strength test. The results were as follows: 1.The bond strength of Lucitone 199 to Acron MC was the highest. 2.The bond strengths of Lucitone 199 and Tokuso rebase to Hi-polycarbonate resulted in a value of approximately one half that of Lucitone 199 to Acron MC,and there were no significant differences between these and the bond strength of Tokuso rebase to Acron MC(p<0.05). 3.The bond strengths of reline resins to Acetal dental were lower than those of reline resins to Hi-polycarbonate. 4.For all base resins Lightdon-U showed lower bond strength than the other reline resins.