Restauración de molares endodonciados, con resina híbrida sobre muñón de amalgama. A propósito de un caso / Restoration of endodontic molars with hybrid resin over amalgam stump. About a case

Introducción: En la actualidad la restauración funcional y estética de dientes endodonciados con gran pérdida de tejido dentario, es efectuada a través del método indirecto; sin embargo, la construcción de muñones de amalgama como elemento de sustitución de metal es una opción terapéutica viable. Objetivo: Mostrar la viabilidad de la restauración estética y funcional de molares endodonciados y con gran pérdida de tejido dentario, por vía directa mediante resina híbrida sobre muñón de amalgama. Presentación del caso: Tratamiento impuesto a un paciente de 35 años con antecedentes de traumatismo dentario condicionantes de fracturas complicadas de corona en 36 y 37, tratados con endodoncias radicales de 2 años de evolución. Acudió a la consulta presentando pérdidas de más de dos tercios del tejido coronal en ambos casos. Luego de comprobar que ambos molares cumplían con los requerimientos, se realizó la preparación de las cavidades, seguida de la confección de muñones de amalgama, sobre los cuales pasadas las 48 horas, se realizó la restauración definitiva con resina híbrida nano composite. Conclusiones: El tratamiento cosmético con nano composite sobre muñón de amalgama, resulta una alternativa terapéutica viable en la restauración estética y funcional por vía directa, aun en molares con gran pérdida de tejido dentario y tratamiento pulporadicular radical(AU)

Introduction: Nowadays functional and aesthetic restoration of endodontic teeth with a great loss of dental tissue, is performed by means of an indirect method, however the construction of amalgams stumps as an element for the metal substitution is a viable therapeutic option. Objective: To show the viability of endodontic molars aesthetic and functional restoration with a great loss of dental tissue, through direct method with resin on amalgam stump. Case Presentation: Treatment applied to a 35-year-old patient with antecedents of traumatism conditioning complicated fractures of crown in 36 and 37, treated with radical endodontic therapy 2 years ago. Arrived to the consulting room presenting losses of more than two thirds of the coronal tissues in both cases. After verifying that both molars met the requirements, the cavities were prepared, followed by the conformation of amalgams stumps over which after 48h, was applied a nano hybrid resin for the definitive restoration. Conclusions: The cosmetic treatment with Nano composite resin over the amalgam stump is an alternative and viable therapy for the functional and aesthetic restoration by means of a direct procedure, even in molars with great loss of dental tissue and subjected to radical endodontic therapy(AU)

Alternativa estética con la utilización de resinas compuestas ante la pérdida de un diente: presentación de un caso / Aesthetic alternative using composite resin to replace a missing tooth: a case report

Frecuentemente, en los casos de trauma dentario donde se pierde definitivamente un diente, los pacientes son rehabilitados protésicamente por cualquiera de sus variantes. Pero no es muy común que un paciente sea rehabilitado con resina compuesta ante la pérdida de un diente. Se presenta el caso de una paciente que años antes había perdido un incisivo central superior, cuyo espacio había sido tomado por el incisivo lateral; a partir del agrandamiento del mismo se conformó el incisivo faltante, mediante la técnica de restauración directa por estratificación o capas, utilizando la resina Brilliant New Line. El objetivo de este trabajo es demostrar una alternativa más económica y fácil de realizar en nuestras consultas por los estomatólogos, con el objetivo de restaurar la estética de un paciente con pronóstico desfavorable(AU)

Patients who experience dental trauma resulting in permanent tooth loss are often prosthetically rehabilitated through any of its variants. However, it is uncommon to rehabilitate a patient using composite resin when a tooth is lost. The case of a patient who had lost a maxillary central incisor years ago and its space had been occupied by the lateral incisor is presented. The missing tooth was built up through the enlargement of the lateral incisor using the layering technique or stratification with Brilliant New Line resin. This paper aims at demonstrating a more economical and simpler alternative for restoring the aesthetics of a patient with unfavorable prognosis(AU)

Effect of ridge-lap surface treatments on the bond of resin teeth to denture base.

PURPOSE: To test in vitro the shear bond strength of resin teeth to an acrylic resin denture base given different ridgelap surface treatments. MATERIALS AND METHODS: Ninety rectangular dies were made with wax and traditionally invested in metallic or plastic flasks. The stone molds were covered with silicone, in which were included an acrylic molar with a wax stick fixed on the ridge lap surface. After deflasking, the wax sticks were removed, the teeth were cleaned with detergent, the ridge lap surface was submitted to different treatments (unmodified, bur-cut grooves, aluminum oxide particle sandblasting, monomer swelling, and primer swelling), and the teeth were replaced in the silicone molds. Metallic flasks were placed in a thermopolymerizing unit to polymerize heat-curing denture-base polymer, and plastic flasks were placed in a domestic microwave oven at 900 W to polymerize microwaveable denture base polymer. After deflasking, the specimens were submitted to the shear bond test in an Instron machine at a cross-speed of 1 mm/min. Results were submitted to ANOVA and Tukey's test (5%). RESULTS: Shear bond strength values were influenced by the ridge-lap surface treatments only in the microwaved polymer. Sandblasting + monomer swelling and sandblasting + primer swelling interactions yielded lower strengths for microwaved polymer. Only the unmodified surfaces presented a significant difference when the resins were compared, where the microwaved polymer showed a higher value. CONCLUSION: Different tooth ridge-lap surface treatments promoted different strengths of the tooth/resin bond.

Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization.

UNLABELLED: Denture fractures are common in daily practice, causing inconvenience to the patient and to the dentists. Denture repairs should have adequate strength, dimensional stability and color match, and should be easily and quickly performed as well as relatively inexpensive. OBJECTIVE: The aim of this study was to evaluate the flexural strength of acrylic resin repairs processed by different methods: warm water-bath, microwave energy, and chemical polymerization. MATERIAL AND METHODS: Sixty rectangular specimens (31x10x2.5 mm) were made with warm water-bath acrylic resin (Lucitone 550) and grouped (15 specimens per group) according to the resin type used to make repair procedure: 1) specimens of warm water-bath resin (Lucitone 550) without repair (control group); 2) specimens of warm water-bath resin repaired with warm water-bath; 3) specimens of warm water-bath resin repaired with microwave resin (Acron MC); 4) specimens of warm water-bath resin repaired with autopolymerized acrylic resin (Simplex). Flexural strength was measured with the three-point bending in a universal testing machine (MTS 810 Material Test System) with load cell of 100 kgf under constant speed of 5 mm/min. Data were analyzed statistically by Kruskal-Wallis test (p<0.05). RESULTS: The control group showed the best result (156.04±1.82 MPa). Significant differences were found among repaired specimens and the results were decreasing as follows: group 3 (43.02±2.25 MPa), group 2 (36.21±1.20 MPa) and group 4 (6.74±0.85 MPa). CONCLUSION: All repaired specimens demonstrated lower flexural strength than the control group. Repairs with autopolymerized acrylic resin showed the lowest flexural strength.

Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization

Denture fractures are common in daily practice, causing inconvenience to the patient and to the dentists. Denture repairs should have adequate strength, dimensional stability and color match, and should be easily and quickly performed as well as relatively inexpensive. OBJECTIVE: The aim of this study was to evaluate the flexural strength of acrylic resin repairs processed by different methods: warm water-bath, microwave energy, and chemical polymerization. MATERIAL AND METHODS: Sixty rectangular specimens (31x10x2.5 mm) were made with warm water-bath acrylic resin (Lucitone 550) and grouped (15 specimens per group) according to the resin type used to make repair procedure: 1) specimens of warm water-bath resin (Lucitone 550) without repair (control group); 2) specimens of warm water-bath resin repaired with warm water-bath; 3) specimens of warm water-bath resin repaired with microwave resin (Acron MC); 4) specimens of warm water-bath resin repaired with autopolymerized acrylic resin (Simplex). Flexural strength was measured with the three-point bending in a universal testing machine (MTS 810 Material Test System) with load cell of 100 kgf under constant speed of 5 mm/min. Data were analyzed statistically by Kruskal-Wallis test (p<0.05). RESULTS: The control group showed the best result (156.04±1.82 MPa). Significant differences were found among repaired specimens and the results were decreasing as follows: group 3 (43.02±2.25 MPa), group 2 (36.21±1.20 MPa) and group 4 (6.74±0.85 MPa). CONCLUSION: All repaired specimens demonstrated lower flexural strength than the control group. Repairs with autopolymerized acrylic resin showed the lowest flexural strength.

Effect of different repair techniques on the accuracy of repositioning the fractured denture base.

OBJECTIVE: This study investigated the efficacy of different techniques for the union of fragments of a denture before repair and on the accuracy of the reposition. MATERIALS AND METHODS: For this study, 20 maxillary dentures made with Lucitone 550 heat-cured resin were used. Points were determined with a scanner on the cusp of the teeth, as a measurement of the segments. After digitisation, each model was exported to the AUTOCAD R 14 program and two-dimensional measurements of the distances between the marked points were made. After the initial analysis, the dentures were fractured into two segments using an impact test machine. For the repair, maxillary dentures were divided into two groups; in the first, the repair was carried out using Kerr's sticky wax and in the second group, Super Bonder was used to join the fragments, with subsequent inclusion of DENTSPLY Repair Material resin. After the repair, the points of the maxillary dentures were measured again. The numerical values obtained were tabulated to compare the measurements before fracture and after the repair. For statistical analysis, analysis of variance was employed, using a single factor and double factor, followed by the Tukey test with a reliability of 95%. RESULTS: The results demonstrated a statistically significant difference between the materials used to join the dentures for repair, where the dentures were joined with sticky wax presented a larger variation in the distances between the points. CONCLUSION: The variation in distances between the points is influenced by the agent of repair.

Strength of denture base resins repaired with auto- and visible light-polymerized materials.

PURPOSE: Clinicians are still confused about the choice of repair method, which depends on factors such as the length of time required for processing, the mechanical strength of the repaired material, and the effect of stress concentration in the acrylic resins before the repair. The aim was to determine the impact and flexural strength characteristics, such as stress at yield, Young's modulus, and displacement at yield of denture base resins fractured and repaired by three methods using heat-, auto-, and visible light-polymerized acrylic resins. MATERIAL AND METHODS: For impact and flexural strength tests, 18 rectangular specimens measuring 50 x 6 x 4 mm(3) and 64 x 10 x 3.3 mm(3), respectively, were processed using Impact 2000, Lucitone 550, Impact 1500, and QC-20 acrylic resins. Fracture tests were performed according to ISO1567:1999. Afterward, all fractured specimens were stored in distilled water at 37 degrees C for 7 days, and then repaired with (1) the same acrylic resin used for specimen fabrication (n = 6), (2) an autopolymerized acrylic resin (TruRepair, n = 6), and (3) a visible light acrylic resin (Versyo.com, n = 6). The repaired specimens were again submitted to the same fracture tests, and the failures were classified as adhesive or cohesive. Data from all mechanical tests after repair by the different methods were submitted to two-way ANOVA, and mean values were compared by the Tukey test. RESULTS: All acrylic resins showed adhesive fractures after impact and flexural strength tests. Differences (p < 0.05) were found among repair methods for all acrylic resins studied, with the exception of displacement at yield, which showed similar values for repairs with auto- and visible light-polymerized acrylic resins. The highest values for impact strength, stress, and displacement at yield were obtained when the repair was made with the same resin the specimen was made of. CONCLUSION: Denture base acrylic resins repaired with the same resin they were made of showed greater fracture strength.

Ceramic restoration repair: report of two cases

The esthetic and functional rehabilitation of patients with multiple missing teeth can be performed with several techniques and materials. Ceramic restorations provide reliable masticatory function and good esthetics. However, fracture can occur in some cases due to their brittle behavior. In some cases, the replacement of an extensive prosthesis is a problem due to the high treatment cost. In this paper, two cases are presented, in which fractures occurred in extensive metal-ceramic fixed partial dentures, and their replacement was not possible. Ceramic repair was chosen and the sequences of treatment with and without presence of the ceramic fragment are also discussed. The cases illustrate that, in some situations, fractured metal-ceramic partial dentures can be successfully repaired when prosthetic replacement is not a choice. Prosthodontists must use alternatives that allow a reliable repair to extensive metal-ceramic fixed partial dentures. Surface preparation of the ceramic with hydrofluoric acid in conjunction with a silane coupling agent is essential for a predictable bonding of composite resin. The repair performed with composite resin is an esthetic and functional alternative when extensive fixed partial dentures cannot be replaced.

The effect of chemical and mechanical treatment of the denture base resin surface on the shear bond strenght of denture / Efeito do tratamento químico e mecânico da superfície da resina de bases de dentaduras nas forças de cisalhamento em reparos de dentaduras

OBJECTIVE: This study was aimed to evaluate the effect of three surface treatment methods on the shearbond strength of denture repairs. MATERIAL AND METHOD: 40 specimens (15 x 15 x 7mm) were fabricated according to the manufacturers’ instructions from each of three denture base materials: a heat-cured acrylic resin (VeracrilTM), a rapid-setting heat-cured acrylic resin (QC-20TM), and a pourable resin (Selecta PlusTM). The samples of each material were divided into four groups of ten. One of the groups served as a control and underwent no surface treatment. The other groups received one of three surface treatments: air blasting with 50 ìm aluminum oxide particles at 0.5 MPa pressure for 5 seconds; immersion in methyl methacrylate (MMA) for 180 seconds or immersion in acetone for 3 seconds. An autopolymerizing repair resin (Rapid RepairTM) was applied to the bonding area (6 mm in diameter, 2 mm in height) and polymerized at a pressure of two bar for 30 minutes using a pressure pot. All specimens were subjected to 10,000 thermal cycles. The shear bond strength (MPa) of the specimens was measured in a universal testing machine at a 1 mm/min crosshead speed. The effect of the mechanical and chemical treatments on the surface of the base resins wasexamined using SEM. Statistical tests used were 2 way ANOVA and Kolmogorov-Smirnov. The level ofstatistical significance was established at (p<0.05). RESULTS: There were statistically significant differencesbetween bond strength in surface treatment levels across acryl level categories (p=0.042). The results also showed differences between treatment levels (p=0.0001).Abrasive blasting significantly increased the bond strength of the repair material, but there were no significant differences between the bond strengths of the control group and the experimental groups treated with MMA or acetone. Examination by SEM revealed that chemical treatment with MMA or acetone produced a smooth surface similar...

OBJETIVO: O presente estudo foi dirigido para avaliação do efeito de três métodos de tratamento de superfície na reparação de resinas-base de dentaduras. MATERIAL E MÉTODO: 40 espécimes (15 x 15 x 7 mm) foram fabricados de acordo com as instruçõesdos fabricantes de cada um de três materiais-base de dentaduras: uma resina termopolimerizada (VeracrilTM); uma resina de termopolimerização rápida (QC-20TM) e uma resina autopolimerizável (Selecta PlusTM). Cada material foi dividido em quatro grupos de dez corpos de prova. Um dos grupos serviu como controle, não recebendo tratamento de superfície. Os outros grupos receberam três tipos de tratamento de superfície: jato abrasivocom partículas de óxido alumínio (50) com pressão de 0,5 MPa durante cinco segundos; imersão em metil metacrilato (MMA) por 180 s; imersão em acetona por três segundos. Uma resina de reparo autopolimerizável (Rapid Repair TM) foi aplicada na área de adesão (6 x 2 mm) e polimerizada sob pressão de duas atmosferas por 30 minutos, utilizando um frasco de pressão. Todos os espécimes foram sujeitos a 10.000 ciclos térmicos. A resistência às forças de cisalhamento foi medida numa máquina universal de testes a uma velocidade de 1 mm/min. O efeito do tratamento químico e mecânico das superfícies da resina base foi avaliado usando SEM. Testes estatísticos utilizados foram ANOVA e Kolmogorov-Smirnov. O nível de significância estatística foi estabelecido a p<0.05. RESULTADOS: Houve diferenças estatisticamente significantes na resistência ao cisalhamento entre as categorias de tratamento de superfície (p=0,042). Os resultados também mostraram diferenças entreníveis de tratamento (p=0,0001). O jato abrasivo aumentou significativamente a resistênciaao cisalhamento do material de reparo, mas não houve diferenças significativas entre a resistência do grupo controle e dos grupos experimentais tratados com MMA ou acetona. O exame com microscopia eletrônica demonstrou que o tratamento químico com MMA...

Ceramic restoration repair: report of two cases.

The esthetic and functional rehabilitation of patients with multiple missing teeth can be performed with several techniques and materials. Ceramic restorations provide reliable masticatory function and good esthetics. However, fracture can occur in some cases due to their brittle behavior. In some cases, the replacement of an extensive prosthesis is a problem due to the high treatment cost. In this paper, two cases are presented, in which fractures occurred in extensive metal-ceramic fixed partial dentures, and their replacement was not possible. Ceramic repair was chosen and the sequences of treatment with and without presence of the ceramic fragment are also discussed. The cases illustrate that, in some situations, fractured metal-ceramic partial dentures can be successfully repaired when prosthetic replacement is not a choice. Prosthodontists must use alternatives that allow a reliable repair to extensive metal-ceramic fixed partial dentures. Surface preparation of the ceramic with hydrofluoric acid in conjunction with a silane coupling agent is essential for a predictable bonding of composite resin. The repair performed with composite resin is an esthetic and functional alternative when extensive fixed partial dentures cannot be replaced.

Efficacy of conventional and experimental techniques for denture repair.

This study investigated the efficacy of one experimental and three conventional techniques for denture repair. Forty maxillary dentures were constructed in dental stone casts duplicated from an edentulous copper-aluminium maxillary master cast. Two groups of 20 dentures each were prepared with Lucitone 199 (water-bath, 8 h/74 degrees C) or Acron MC (microwave, 3 min/500 W) denture base materials processed in gypsum moulds. The 40 dentures were all separated sagittally in the middle. After that, five dentures of each denture base material were repaired with one of the four following techniques: L (Lucitone 199, water-bath, 8 h/74 degrees C, gypsum mould), A (Acron MC, microwave, 3 min/500 W, gypsum mould), AR (Acron MC/R, autopolymerized, 60 psi/45 degrees C/15 min) and the experimental technique AS (Acron MC, 1 min/500 W + 1 min/0 W + 1 min/500 W, hard silicone mould). The parameters denture accuracy (DA), horizontal (HC) and vertical changes (VC) of the occlusal plane measured the efficacy of the repair techniques. The DA was determined by weighing a film of silicone impression material set in contact to the tissue surface of the denture seated on the metallic master die. For HC, cross-arch measurements were made among reference marks drilled on the teeth 11, 21, 16 and 26. The VC was obtained by calculating the relative differences in height between similar teeth of each semi-arch (pairs 13-23, 14-24, 15-25 e 16-26). For DA, HC and VC, the percentage differences between the percentage means obtained before and after repair were calculated and grouped for comparisons. Analysis of variance (SuperANOVA) and means compared by Tukey-Kramer intervals (0.05) revealed that AR repair had the best percentage difference value for DA [0.5% (P < 0.05)], while the others were not statistically different [L = 27.2%, A = 28.9%, AS = 21.2% (P > 0.05)]. For HC, there was a statistical difference (P < 0.05) between AR and the other techniques for the tooth pairs, 16-26, 11-26 and 21-16; repairs with AR and AS differed for the 11-21 pair, while those with A and AS techniques differed for the 16-26 pair (P < 0.05). The VC differences were not detected between repair methods (P > 0.05). Denture accuracy was not affected by the interaction of base material-repair technique; repair with AR technique gave the best adaptation; the interaction of base material-repair technique did not affect HC; HC was affected by the repair technique.

Sistema perno muñón vaciado metálico / Metalic cast dowel-core system

La presente revisión bibliográfica recopila en forma breve, los primeros intentos por devolver forma y función a piezas con su estructura coronaria comprometida. Desde Fauchard, hasta la aparición de los sistemas perno muñón vaciados metálicos, elementos que por primera vez permiten de un modo definitivo, independizar la solución estética de la recuperación de la pieza endodónticamente tratada. Haciendo especial hincapié en su forma, longitud, diámetro, adaptación, superficie, resistencia, propiedades y aleaciones en que usualmente se construyen

Replacement of a fractured tooth on a removable partial denture by using two visible light-cured resin systems.

A method has been described to repair or place a tooth on an RPD by veneering VLC resin with microfilled composite resin. The entire procedure is efficient, economical, and can be performed chairside. It minimizes the dentist's dependency on an outside laboratory and presents minimal inconvenience to the patient.