Effect of different design and surface treatment on the load-to-failure of ceramic repaired with composite / Efeito de diferentes tratamentos de superficie e formas do preparo de cerámicas na resistencia de uniao de reparos em resina composta

ABSTRACT Glass ceramics are widely used to manufacture esthetic veneers, inlays, onlays, and crowns. Although the clinical survival rates ofglass-ceramic restorations arefavorable,fractures or chips are common. Certain cases can be repaired with direct composite. Aim The aim of this study was to investigate the interaction effect of different designs and surface treatments on the load-to-failure of lithium disilicate glass-ceramic repaired with nanofilled composite. Materials and Method Lithium-disilicate glass-ceramic slabs (IPS e.max Press, Ivoclar Vivadent) with three different designs of the top surface (flat, single plateau, or doubleplateau) (n=U) received 'no treatment', '5% HF etching', or "AI2O3 sandblasting". HF-etched and sandblasted slabs also received silane and universal one-step adhesive application. All slabs were incrementally repaired with nanofilled composite (Filtek Z350, 3M ESPE) up to6 mm above the highest ceramic top plateau. Specimens were stored in artificial saliva at 37 °C for 21 days and then subjected to 1,000 thermocycles between 5 and 55 °C. The interface composite-ceramic of each specimen was tensile tested until failure in a universal testing machine and the mode of failure was determined under a stereomicroscope. The ceramic surface morphology of one representative tested specimen from each subgroup (design/surface treatment) was observed through scanning electron microscopy (SEM). Results Regardless of ceramic design, the absence of surface treatment resulted in significantly lower load-to-failure values. No significant differences in load-to-failure values were observed between HF-etched and sandblasted specimens for the flat design; however, HF etching resulted in significantly higher load-to-failure values than sandblasting for both single plateau and double plateau designs. The majority (60%) of HF-etched specimens with single plateau or double plateau presented mixed failures. SEM photomicrographs showed that HF-etched specimens had smoother surfaces than sandblasted specimens. Conclusion The surface treatment of a defective lithium disilicate glass-ceramic restoration has more influence than its macroscopic design on the retention of the composite repair. HF etching seems to provide higher bond strength to the composite repair.

RESUMO Embora fraturas e lascamento de restauragoes vitrocerámicas sejam comuns, alguns casos podem ser reparados com compósito direto. Objetivo investigar o efeito da interagao de diferentes formas e tratamentos de superficie na carga de ruptura de uma vitrocerámica reforgada com dissilicato de litio reparada com compósito nanoparticulado. Materials e Método A superficie superior de espécimes de vitroceramica (IPS e.max Press, Ivoclar Vivadent) foi preparada com tres formas (plana, plato único, ou duplo) e recebeu (n=11): 'nenhum tratamento', 'condicionamento com ácido hidrofluoridrico 5%', ou 'jateamento com AfOf. Ambos espécimes condicionados e jateados receberam silano e adesivo universal. Todos os espécimes foram reparados incrementalmente com compósito (Filtek Z350, 3M ESPE) até6 mm acima do plato cerámico mais alto, armazenados em saliva artificial á 37 °C por 21 dias, e submetidos á 1.000 termociclos (5 e 55 °C). A interface compósito-cerámica de cada amostra foi testada á tragao até sua falha em máquina universal e o modo de falha foi determinado com estereomicroscópio. A morfologia da superficie de uma amostra representativa de forma/tratamento de superficie foi observada através de microscopia eletronica de varredura (MEV). Resultados Independentemente da forma ceramica, a ausencia de tratamento superficial resultou em valores de carga de ruptura significativamente menores. Nao foi observada differenga significativa entre os espécimes planos condicionados ou jateados; no entanto, o condicionamento resultou em valores significativamente maiores que o jateamento para espécimes com plato único e duplo. A maioria (60%) dos espécimes condicionados e com plato único ou duplo apresentou falhas mistas. Imagens SEM demonstraram rugosidade superficial mais regular dos espécimes condicionados que os jateados. Conclusoes O tratamento superficial de uma restauragao defeituosa de vitrocerámica reforgada por dissilicato de litio tem maior influencia na retengao do reparo de compósito do que sua forma macroscópica; ainda, o condicionamento com ácido hidrofluoridrico parece proporcionar maior resistencia de uniao ao reparo com compósito.

Restoration-repair potential of resin-modified glass ionomer cement

Abstract: This in vitro study aimed to evaluate the repair bond strength of resin-modified glass ionomer cement using either the same material or a universal adhesive in the etch-and-rinse and self-etch modes plus resin composite. Twenty-four resin-modified glass ionomer cement blocks were stored in distilled water for 14 d and thermocycled. Sandpaper ground specimens were randomly assigned to three experimental groups according to the repair protocol: resin-modified glass ionomer cement (Riva Light Cure, SDI) and universal adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in etch-and-rinse or self-etch modes and nanohybrid resin composite (Z350 XT, 3M Oral Care). After 24 h of water storage, the blocks were sectioned, and bonded sticks were subjected to the microtensile bond strength (μTBS) test. One-way ANOVA and Tukey's test were used to analyze the data. The failure mode was descriptively analyzed. The highest μTBS values were obtained when the resin-modified glass ionomer cement was repaired using the same material (p < 0.01). In addition, the mode of application of the universal adhesive system did not influence the repair bond strength of the resin-modified glass ionomer cement. Adhesive/mixed failures prevailed in all groups. Repair of resin-modified glass ionomers with the same material appears to be the preferred option to improve bond strength.

Evidence-practice gap in treatment decisions about defective composite and amalgam restorations among Brazilian dentists

Better understanding of dentists' decision-making about defective restorations is needed to close the evidence-practice gap (EPG). This study aimed to quantify the EPG about defective restorations and identify dentist factors associated with this EPG. Methods: 216 dentists from São Paulo State, Brazil, completed a questionnaire about three clinical case scenarios involving defective composite restorations with cementum-dentin margins (case 1) and enamel margins (case 2), and an amalgam (case 3) restoration. Dentists were asked what treatment, if any, they would recommend, including preventive treatment, polishing, re-surfacing, or repairing the restoration, or replacing the entire restoration. Replacing the entire restoration in any of these three scenarios was classified as inconsistent with the evidence, comprising an EPG. Bivariate analyses using Chi-square, ANOVA, or multiple comparison tests were performed (p<.05). Results: for defective composite restorations, 49% and 55% of dentists chose to replace the entire restoration for cases 1 and 2, respectively. Twenty-nine percent of dentists chose to replace the entire amalgam restoration. Dentists were significantly more likely to choose to replace the defective amalgam restoration than the composite restoration with a defect at the cementum-dentin margins or the enamel margins (both at p < .001). Female dentists were more likely to choose a conservative treatment than male dentists for cases 1 (p=.034) and 2 (p=.009). Dentists with a higher percentage of patients interested in individualized caries prevention were also more conservative in case 1 (p=.045). Conclusion: a substantial EPG regarding treatment decisions for defective restorations exists, especially for composite restorations. This study adds to the international evidence that an EPG exists in this clinical area and that global strategies need to be developed to close the gap

Minimum intervention oral care: defining the future of caries management

Abstract It is not uncommon that oral healthcare professionals and researchers interchange the use of the terms minimum/minimal intervention and minimally invasive dentistry. However, these terms apply to two different, but related, concepts. Minimum intervention dentistry, to be more appropriately addressed in this paper as minimum intervention oral care (MIOC), is an oral healthcare delivery framework that encompasses four interlinked clinical domains. These domains are: identifying disease - detection, longitudinal risk/susceptibility assessment, investigation, diagnosis and the development of a personalized care plan; prevention of lesions/control of disease - patient behaviour management, non-invasive remineralisation of the enamel and dentine, biofilm and diet control, micro-invasive sealants and infiltration techniques to arrest and reverse incipient lesions; minimally invasive operative procedures including selective carious dentine removal, the "5Rs" management of the tooth-restoration complex (review, refurbish, re-seal, repair and replace) amongst other restorative interventions; and tailored recall/review/re-assessment consultations. This framework includes that minimally invasive operative dentistry (MID), that although a critical operative clinical domain, should be viewed as one of the pillars of minimum intervention oral healthcare (MIOC), applied across all disciplines of restorative dentistry, not just caries management. The aim of this review is to clarify these differences and emphasize the importance of minimally invasive operative dentistry (MID) within the context of minimum intervention oral care (MIOC). MIOC is applicable to all disciplines within restorative dentistry, including clinical caries management.

Percepción de estudiantes respecto al recambio de restauraciones / Students' perception regarding the replacement of restorations

Introducción: El reemplazo de restauraciones defectuosas representa la mayor parte de la práctica del odontólogo, lo que lleva a una perdida mayor del remanente dentario ante cada reemplazo. Objetivo: Determinar si existe variación del criterio clínico en alumnos frente a la decisión de recambio en restauraciones de resina compuesta previo y posterior al reacondicionamiento. Material y Métodos: Estudio analítico transversal. Se contó con una muestra de 40 estudiantes de quinto año de un universo de 72. Se utilizó un set fotográfico, que contaba con restauraciones defectuosas, en uno o más parámetros según los criterios RYGE/USPHS, las cuales posteriormente se reacondicionaron, por lo que se contaba con las fotografías del antes y del después del tratamiento conservador. Se realizó una encuesta a partir de las fotografías mostradas en la cual debían indicar la elección de tratamiento. Resultados: Se observó que hay una gran variación de elección de tratamiento previo a ser reparadas con tratamientos conservadores: 38 por ciento y no conservador de 62 por ciento y frente a la misma restauración de resina posterior a haber sido intervenida la elección de tratamiento conservador fue de 83 por ciento y no conservador 17 por ciento. Mediante el Test de McNemar se obtuvo un p<0.0001 entre elección de tratamiento conservador por sobre el no conservador posterior a haber sido realizada el reacondicionamiento de la restauración. Conclusiones: Existe un cambio en la percepción sobre la indicación de tratamiento de restauraciones defectuosas, a favor de una alternativa conservadora, después de que han sido intervenidas con procedimientos mínimamente invasivos(AU)

Introduction: The replacement of defective restorations, which leads to a greater loss of the dental remnant before each replacement, represents the large majority of the dentist's practice. Objective: To determine if there is any variation in students´ clinical criterion in relation to the decision of replacement of composite resin restorations prior to and following reconditioning. Material and Methods: A cross-sectional analytical study was conducted. The sample was composed of 40 fifth-year students in a universe of 72. A set of photographs showing defective restorations in one or more parameters evaluated according to RYGE / USPHS criteria was used. They were later reconditioned, so there were photographs prior to and following conservative treatment. Based on the photographs shown, a survey in which they had to indicate the choice of treatment was performed. Results: We observed that there is a great variation in the choice of treatment prior to the repair with conservative treatments (38 percent) and non-conservative ones (62 percent), compared to the same resin restoration after the choice of conservative treatment (83 percent) and non-conservative one (17 percent). Using the McNemar Test, p<0.0001 was obtained between the choice of conservative treatment over the non-conservative one after the restoration reconditioning had been performed. Conclusions: There is a change in perception of the indication of treatment to repair defective restorations towards a conservative alternative after they have undergone minimally invasive procedures(AU)

Recomendaciones sobre la reparación de restauraciones de amalgama / Recommendations about the repair of dental amalgam restorations

Introducción: La reparación de restauraciones de amalgama, los materiales, las caras de los dientes de preferencia para realizarlas y su controversia con la contraparte de realizar reemplazos, es algo que amerita atención por los investigadores para lograr definiciones y protocolos precisos. Objetivo: Sistematizar sobre las recomendaciones de la literatura con respecto a la reparación de restauraciones de amalgama. Métodos: Se realizó una revisión cualitativa. Se plantearon criterios de inclusión y exclusión para la selección de los artículos. La búsqueda se realizó en Scopus y Pubmed. De las investigaciones resultantes de la búsqueda fueron decantados los artículos que no coincidían con el problema de investigación en cuestión, luego los que no cumplían los criterios de inclusión y exclusión. Se realizó una evaluación de la calidad y validez de los artículos seleccionados para ser incluidos en esta investigación y, finalmente, se le dio lectura a los textos completos y resúmenes para extraer los datos necesarios para completar la base de datos de la investigación. Quedaron un total de 27 artículos que fueron tamizados en una base de datos Excel, la que luego se exportó al software SPSS para su procesamiento estadístico. Resultados: El 44,4 por ciento y 55,6 por ciento de los artículos recomiendan reparar las restauraciones con amalgama y resina compuesta, respectivamente. Casi la mitad de los artículos (48,1 por ciento) no precisaron una cara del diente susceptible o no para realizar reparaciones. El 44,4 por ciento concluyen con que es un tratamiento recomendable. Conclusiones: Es recomendable realizar reparaciones de restauraciones de amalgama con amalgama dental y con resina compuesta. No está claramente definido cuál cara del diente es susceptible o no a recibir reparaciones y es un tratamiento que puede formar parte del arsenal terapéutico de los odontólogos(AU)

Introduction: The repair of amalgam restorations, the materials used, the tooth sides preferred to perform them, and the controversy with the replacement option, are all topics deserving the attention of researchers with a view to achieving accurate definitions and protocols. Objective: Systematize the recommendations available in the literature about the repair of amalgam restorations. Methods: A qualitative review was carried out. Inclusion and exclusion criteria were established for the selection of papers. The search was conducted in Scopus and Pubmed. Papers not related to the research problem at hand were the first to be discarded. Then those not meeting the inclusion and exclusion criteria. An evaluation was performed of the quality and validity of the remaining papers, and finally their full texts and abstracts were read to retrieve the data required to complete the database of the study. The 27 papers thus obtained were sifted in an Excel database, which was then exported to the SPSS software for statistical processing. Results: 44.4 percent and 55.6 percent of the papers recommend to repair restorations with amalgam and composite resin, respectively. Almost half (48.1 percent) do not state any preference for a specific tooth side to perform the repair. 44.4 percent recommend the treatment. Conclusions: It is advisable to perform repairs of amalgam restorations with dental amalgam and with composite resin. It is not clearly defined which tooth side is preferred to undergo the repair. This treatment may be part of the therapeutic arsenal of dentists(AU)

Como reparar uma restauração oclusal de resina composta em dentes decíduos? Relato de caso / How to repair an occlusal composite resin restoration on primary teeth? Case report

Frente à necessidade de reintervenção em restaurações insatisfatórias, os clínicos podem, em geral, optar pela substituição ou reparo. Este artigo relata um caso clínico de reparo de uma restauração de resina composta com falha em dente decíduo. Após profilaxia e isolamento relativo, a porção da resina composta a ser reparada foi asperizada com uma ponta diamantada em alta rotação com o intuito de melhorar a união mecânica entre a resina envelhecida e a nova (reparo). Foi realizado o condicionamento com gel de ácido fosfórico a 34% por 15 segundos, seguido de lavagem e secagem. Uma camada do sistema adesivo Single Bond Universal (3M ESPE) foi aplicada ativamente durante 20 segundos, seguido de jato de ar comprimido por 5 segundos e fotoativação por 10 segundos. Por fim, a resina composta fluida (Filtek Z350 XT Flow; 3M ESPE) foi inserida e fotoativada por 20 segundos. A realização de um adequado protocolo clínico envolvendo tratamentos físicos e químicos de superfície é fundamental para a efetividade da intervenção e a manutenção do dente decíduo clinicamente funcional até a esfoliação fisiológica.

Facing need for reintervention in unsatisfactory resto-rations, clinicians may generally choose for replacement or repair. This paper reports a clinical case of repair of a composite resin restoration with failure in primary tooth. After prophylaxis and relative isolation, the portion of the composite resin to be repaired was roughed with a high-speed diamond bur to improve the mechanical bond between the aged and new resin (repair). Conditioning with 34% phosphoric acid gel was performed for 15 seconds, followed by washing and drying. One layer of the adhesive system Single Bond Universal (3M ESPE) was actively applied for 20 seconds and light- cured for 10 seconds. Finally, the flowable composite resin (Filtek Z350 XT Flow; 3M ESPE) was inserted and light-cured for 20 seconds. An adequate clinical protocol involving physical and chemical surface treatments is essential for the effectiveness of the intervention and the main-tenance of the primary tooth clinically functional until physiological exfoliation.

Effect of surface treatments and universal adhesive application on the microshear bond strength of CAD/CAM materials

PURPOSE: The aim of this study was to evaluate the microshear bond strength (µSBS) of four computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three different surface treatment protocols.MATERIALS AND METHODS: Four different CAD/CAM blocks were used in this study: (1) flexible hybrid ceramic (FHC), (2) resin nanoceramic (RNC), (c) polymer infiltrated ceramic network (PICN) and (4) feldspar ceramic (FC). All groups were further divided into four subgroups according to surface treatment: control, hydrofluoric acid etching (HF), air-borne particle abrasion with aluminum oxide (AlO), and tribochemical silica coating (TSC). After surface treatments, silane was applied to half of the specimens. Then, a silane-containing universal adhesive was applied, and specimens were repaired with a composite, Next, μSBS test was performed. Additional specimens were examined with a contact profilometer and scanning electron microscopy. The data were analyzed with ANOVA and Tukey tests.RESULTS: The findings revealed that silane application yielded higher µSBS values (P<.05). All surface treatments were showed a significant increase in µSBS values compared to the control (P<.05). For FHC and RNC, the most influential treatments were AlO and TSC (P<.05).CONCLUSION: Surface treatment is mandatory when the silane is not preferred, but the best bond strength values were obtained with the combination of surface treatment and silane application. HF provides improved bond strength when the ceramic content of material increases, whereas AlO and TSC gives improved bond strength when the composite content of material increases.

Does use of silane-containing universal adhesive eliminate the need for silane application in direct composite repair?

Abstract This in vitro study aimed to evaluate the effect of a silane-containing universal adhesive used with or without a silane agent on the repair bond strength between aged and new composites. Forty nanohybrid composite resin blocks were stored in distilled water for 14 d and thermo-cycled. Sandpaper ground, etched, and rinsed speciments were randomly assigned into four experimental groups: silane + two-step etch-and-rinse adhesive system, two-step etch-and-rinse adhesive system, silane + silane-containing universal adhesive system, and silane-containing universal adhesive system. Blocks were repaired using the same composite. After 24 h of water storage, the blocks were sectioned and bonded sticks were submitted to microtensile testing. Ten unaged, non-repaired composite blocks were used as a reference group to evaluate the cohesive strength of the composite. Two-way ANOVA and Tukey's tests were used to analyze average µTBS. One-way ANOVA and Dunnet post-hoc tests were used to compare the cohesive strength values and bond strength obtained in the repaired groups (α = 0.05). The µTBS values were higher for the silane-containing universal adhesive compared to the two-step etch-and-rinse adhesive system (p = 0.002). Silane application improved the repair bond strength (p = 0.03). The repair bond strength ranged from 39.3 to 65.8% of the cohesive strength of the reference group. Using universal silane-containing adhesive improved the repair bond strength of composite resin compared to two-step etch-and-rinse adhesive. However, it still required prior application of a silane agent for best direct composite resin repair outcomes.

Reparación de defecto localizado en restauración de amalgama como tratamiento de mínima intervención en cariología / Repair of a localized defect in a restoration with amalgam filling as minimal intervention treatment in cariology

Introducción: La reparación de restauraciones ha sido estudiada desde muy recientemente, pero a pesar de haber demostrado efectividad y mejoras en la terapéutica de la caries dental, aún tiene seguidores y detractores, lo que justifica la necesidad de estudios que sigan avalando tales prácticas. Objetivo: Describir, a través de la presentación de un caso, la reparación de un defecto localizado en una restauración de amalgama como tratamiento de mínima intervención en cariología. Presentación del caso: Paciente femenina de 16 años con antecedentes de salud acude a consulta refiriendo una pequeña fractura de restauración en diente 4.6 desde hace varias semanas. La regularización del defecto en la restauración, la mínima preparación cavitaria, la eliminación del fragmento de la base intermedia, la protección del complejo dentino-pulpar y el llenado de la cavidad resultante, fueron los primeros pasos de una técnica que se cumplimentó luego del pulido final de la interface tejido dentario-restauración y se evolucionó cinco años después. Se evidenció el estado y presencia de la reparación de la restauración realizada, sin fracturas añadidas, microfiltraciones, sintomatologías, desplazamientos ni pérdidas de la continuidad. Conclusiones: La reparación del defecto localizado de amalgama se realizó con el fin de preservar los tejidos dentarios no afectados como lo dicta la mínima intervención en cariología. Cinco años más tarde, la evolución evidencia una práctica que se tradujo en resultados satisfactorios e incremento de la calidad de vida de la paciente(AU)

Introduction: Restoration repair has been studied recently; but, even when it has demonstrated effectiveness and improvements in the therapy of dental caries, it still has followers and detractors that justify the need for studies that continue supporting such practices. Objective: To describe, through a case presentation, the repair of a defect located in a restoration with amalgam filling as minimal intervention treatment in cariology. Case presentation: Sixteen-year-old female patient with health history that went to the clinic reporting a small fracture of a restoration performed in tooth 4.6 several weeks ago. The regularization of the defect in the restoration, minimum cavity preparation, elimination of the fragment of the intermediate base, protection of the dentin-pulp complex, and filling of the resulting cavity were the first steps of a technique that was completed after the final polishing of the dental tissue/restoration interface that was evolved five years later. The status and presence of the restoration repair performed without added fractures, microfiltration, symptomatology, displacement or loss of continuity was evidenced. Conclusions: The repair of the localized defect in a restoration with amalgam filling was performed with the aim of preserving the unaffected dental tissues as dictated by minimal intervention in cariology. Five years later, the patient´s evolution shows a practice that resulted in satisfactory results and an increase in the patient's quality of life(AU)

Efeito da aplicação de plasma não-térmico atmosférico no reparo de cerâmicas CAD/CAM de matriz resinosa com resina composta / Effect of non-thermal atmospheric plasma application on the resin composite repair of resin matrix CAD/CAM ceramics

O objetivo deste trabalho foi avaliar o efeito do plasma atmosférico não-térmico (PANT), sozinho ou associado ao jateamento ou adesivo, e do tempo de armazenamento em água na resistência de união por cisalhamento (RUC) do reparo de cerâmicas CAD/CAM de matriz resinosa (CMR) com resina composta. Amostras de 14x7x1mm de três CMRs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.) e Lava Ultimate (3M Oral Care), foram obtidas e submetidas ao envelhecimento artificial (EQ-UV, Equilam) por 300 horas. Os seguintes tratamentos de superfície foram realizados: (1- Controle) jateamento + silano + adesivo; (2) PANT; (3) PANT + adesivo; (4) jateamento + PANT. Cilindros de resina composta (Spectra Smart, Dentsply Sirona, 1,5 mm diâmetro e altura) foram aderidos às superfícies tratadas e a RUC foi avaliada em uma máquina de ensaio universal (EZ Test, Shimadzu) após 24 horas ou 1 ano de imersão em água, a 37oC (n=10). No geral, o tratamento controle obteve os melhores resultados de RUC, comparado aos grupos tratados com PANT. Houve redução da RUC após 1 ano de imersão em água para a maioria dos grupos, entre eles para o controle do Enamic e Lava Ultimate, enquanto Cerasmart não mostrou redução. O tratamento com PANT, sozinho ou associado a outro tratamento, não foi capaz de aumentar a RUC do reparo das CMRs com resina composta. O tratamento controle parece ser o melhor método de reparo das CMRs, principalmente considerando-se a longevidade do tratamento.

The objective of this study was to evaluate the effect of nonthermal atmospheric plasma (NTAP), alone or combined with sandblasting or adhesive, and water-storage time on the shear bond strength (SBS) of resin composite repair of resin matrix ceramics (RMC). Samples (14x7x1mm) of three RMCs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.), and Lava Ultimate (3M Oral Care), were prepared and submitted to artificial aging (EQ-UV, Equilam) for 300 h. The following surface treatments were performed: (1- Control) sandblasting + silane + adhesive; (2) NTAP; (3) NTAP + adhesive; (4) sandblasting + NTAP. Resin composite cylinders (Spectra Smart, Dentsply Sirona, 1,5 mm diameter and height) were bonded to the treated surfaces and the SBS was evaluated in a universal testing machine (EZ Test, Shimadzu) after 24 h or 1 year of water storage, at 37oC (n=10). In general, the control treatment obtained the best SBS results, compared to groups treated with NTAP. There was a decrease in SBS after 1 year of water immersion for most groups, including the control treatment for Enamic and Lava Ultimate, while Cerasmart presented no reduction. The treatment with NTAP alone or combined with another treatment, was not capable of increasing the SBS of resin composite repair to RMCs. Control treatment seems to be the best method for repairing CMRs, mainly considering the treatment longevity.

Influence of different universal adhesives on the repair performance of hybrid CAD-CAM materials

OBJECTIVES: The aim of this study was to investigate the microshear bond strength (μSBS) of different universal adhesive systems applied to hybrid computer-aided design/computer-aided manufacturing (CAD-CAM) restorative materials repaired with a composite resin. MATERIALS AND METHODS: Four types of CAD-CAM hybrid block materials—Lava Ultimate (LA), Vita Enamic (VE), CeraSmart (CS), and Shofu Block HC (SH)—were used in this study, in combination with the following four adhesive protocols: 1) control: porcelain primer + total etch adhesive (CO), 2) Single Bond Universal (SB), 3) All Bond Universal (AB), and 4) Clearfil Universal Bond (CU). The μSBS of the composite resin (Clearfil Majesty Esthetic) was measured and the data were analyzed using two-way analysis of variance and the Tukey test, with the level of significance set at p < 0.05. RESULTS: The CAD-CAM block type and block-adhesive combination had significant effects on the bond strength values (p < 0.05). Significant differences were found between the following pairs of groups: VE/CO and VE/AB, CS/CO and CS/AB, VE/CU and CS/CU, and VE/AB and CS/AB (p < 0.05). CONCLUSIONS: The μSBS values were affected by hybrid block type. All tested universal adhesive treatments can be used as an alternative to the control treatment for repair, except the AB system on VE blocks (the VE/AB group). The μSBS values showed variation across different adhesive treatments on different hybrid CAD-CAM block types.

Skin color affect the replacement of amalgam for composite in posterior restorations: a birth-cohort study

Abstract The aim of present study was to estimate the occurrence and associated factors for replacement of amalgam posterior restorations. A representative sample of all 5,914 births from the 1982 in Pelotas birth cohort study was prospectively investigated, and the posterior restorations were assessed at 24 (n = 720) and 31 years of age (n = 539). Individual-level variables, i.e., demographic characteristics, socio-economic factors, oral health conditions and use of dental services, were collected from different waves of the cohort. Tooth-level variables included dental group, estimated time in mouth of each amalgam restoration, and number of restored dental surfaces. Thus, 246 individuals presented 718 amalgam restorations at 24 years of age. After 7 seven years of follow-up, 18.9% of these restorations had been replaced with composite resins. Multilevel Poisson regression models showed that, compared to white individuals, blacks presented a lower risk of replacement of amalgam restorations for composite resins (IRR - 0.39 [0.16-0.95]). Individuals with high educational level at age 31 showed an increased likelihood of replacement of amalgam restorations. Therefore, skin color affects the replacement of amalgam for composite resin in posterior restorations.

Avaliação radiográfica da interface de reparo em resina bulk fill / Radiographic evaluation of repair interface in bulk fill resin

Objetivo: avaliar radiograficamente a interface de reparo em resina bulk fill (Opus bulk fill ­ FGM) com diferentes protocolos de adesão. Metodologia: foram confeccionados 30 corpos de prova em formato de cubo, nas dimensões de 4mm x 6mm. Os corpos foram randomizados e divididos entre os grupos: G1: ácido fosfórico a 37% (Dentsply) + adesivo (Ambar ­ FGM); G2: ácido fosfórico a 37% (Dentsply) + silano (Prosil ­ FGM) + adesivo (Ambar­FGM) e G3: Adesivo auto-condicionante (Ambar universal ­ FGM). Após os tratamentos, os corpos foram posicionados em uma matriz metálica de 4mm x 8mm para receber novos incrementos de resina bulk fill. Para análise do reparo, as amostras foram submetidas a radiografias digitais (Micro Imagem), com disparo de 0,16 segundos. Aplicou-se o efeito de contraste filtro de tele MI para permitir a avaliação visual. Para análise estatística foi utilizado o teste exato de Fisher. Resultados: o grupo 2 apresentou em metade dos espécimes avaliados, uma interface não visível, porém, não diferiu estatisticamente dos outros grupos que em sua maioria apresentaram a interface visível em mais de 50% da extensão do reparo. Conclusão: os protocolos realizados na interface da resina bulk fill não foram suficientes para gerar diferenças entre as imagens dos grupos tratados.

Objective: evaluate radiographically repair interface in bulk fill resin (Opus bulk fill-FGM) with different protocols of adhesion. Metodology: 30 specimens on the dimensions of 4 mm x 6 mm were made in cube formate. The specimens were randomized and divided between the groups: G1: phosphoric acid at 37% (Dentsply) + sticker (Ambar-FGM), G2: phosphoric acid at 37% (Dentsply) + silane (Prosil-FGM) + sticker (Ambar-FGM) and G3: Self-etching adhesive (universal Amber-FGM). After the treatments, the specimens were placed in a 4 mm x 8 mm metal matrix to receive new increments of resin bulk fill. For the repair analysis, samples were submitted to digital x-rays (Micro image), with triggering of 0.16 seconds. The filter contrast effect tele filter MI to allow visual assessment was applied. For statistical analysis we used the Fisher exact test. Results: group 2 presented in half of the specimens evaluated a not visible interface, however did not differ statistically from the other groups in that in their majority presented the visible interface in more than 50% of the repair extent. Conclusion: the protocols carried out in bulk fill resin interface were not sufficient to generate differences between the images of the treated groups.

Influencia del silano y adhesivos universales en la adhesión durante la reparación de un cerómero / Influence of silane and universal adhesives on adhesion during the repair of a ceromer

RESUMEN Introducción: No existe un protocolo definitivo para la reparación de cerómeros. Los adhesivos universales debido a su composición e indicaciones pueden ser una alternativa dentro de la reparación de restauraciones poliméricas, pero la asociación de los silanos con los adhesivos universales requiere más investigación. Objetivo: Evaluar y comparar la resistencia de unión de dos adhesivos universales en la interfase cerómero-resina, asociado o no a un agente silano. Material y métodos: Se realizaron seis bloques de cerómero y se trataron según las siguientes variables: (A) sin tratamiento, (B) agente silano, (C) adhesivo universal 1 + silano, (D) adhesivo universal 1, (E) adhesivo universal 2 + silano, (F) adhesivo universal 2 (n = 10). Se unió resina compuesta a dichas superficies y se realizó prueba de microtensión. El tipo de falla se evaluó con estereomicroscopio. Resultados: Los valores de resistencia de unión de los grupos fueron estadísticamente diferentes (p < 0.05), excepto entre ambos adhesivos universales evaluados. El grupo B presentó los valores más altos de resistencia adhesiva. Los grupos C y E obtuvieron valores de resistencia adhesiva menores en comparación con los grupos D y F. El tipo de falla predominante fue el adhesivo. Conclusión: El uso asociado de un silano funcional con los adhesivos universales no mejora los valores de resistencia adhesiva, por lo que debería evitarse. Como primera elección se recomienda el silano funcional, y en segundo grado, sólo usar adhesivos universales, pero no asociar los dos materiales en un mismo proceso adhesivo.

ABSTRACT Introduction: There is no definitive protocol for ceromer repairs. Universal adhesives due to their composition and indications may be an alternative for polymeric restorations repair. But the association of silanes with universal adhesives requires more research. Objective: To evaluate and compare the bond strength of two universal adhesives in ceromer - resin interface, associated or not with a silane agent. Material and methods: Six ceromer blocks were made and treated according to the following variables: (A) No treatment, (B) Silane agent, (C) Universal Adhesive 1 + Silane, (D) Universal Adhesive 1, (E) Adhesive Universal 2 + Silane, (F) Universal Adhesive 2 (n = 10). Composite resin was attached to these surfaces and a microtension test was performed. The type of failure was evaluated with a stereomicroscope. Results: The bond strength values of the groups were statistically different (p <0.05), except between both universal adhesives were evaluated. Group (B) presented the highest values of adhesive resistance. Groups (C and E) had lower adhesive strength values compared to groups (D and F). The most prevalent type of failure was the adhesive. Conclusion: The associated use of functional silane to universal adhesives does not improve adhesive strength values, so it should be avoided. As a first choice, functionalsilane is recommended, and in the second degree, only use universal adhesives, but do not associate the two materials in the same adhesive process.

One-year aging effects on microtensile bond strengths of composite and repairs with different surface treatments

Abstract The present study aimed to evaluate effects of different surface treatments and aging of composite cylinders on bond strength of composite resin repair. Thirty-two composite cylinders were produced and divided into four groups according to type of surface treatment and storage time of composite cylinder and repair. Cylinder surface of control group (Gcontrol) received no treatment before composite repair. Other groups were sandblasted with aluminum oxide (GAl2O3), followed by silane (GAl2O3sil) or adhesive (GAl2O3ad). Composite cylinders were stored in artificial saliva for either 24 hours or 1 year. Repairs were performed and stored in artificial saliva for 24 hours or 1 year and repair strength was evaluated using microtensile bond strength test. Data were submitted to Student’s t test, two-way ANOVA, and post hoc test for storage time and treatment (α = 0.05). Gcontrol group showed lower values of aging of composite cylinder and storage time of repair (24 hours or 1 year for both) compared with other groups (p < 0.05). GAl2O3ad and GAl2O3sil groups did not exhibit decreased microtensile bond strength with aged repairs (1 year; p > 0.05). Polymer degradation was significant for composite cylinders during the first year of storage in Gcontrol, GAl2O3, and GAl2O3ad groups (p < 0.05). In GAl2O3sil group, storage time of composite cylinders was not significant (p > 0.05). Aging of composite resin influenced bond strength of restoration repair for up to 1 year. Sandblasting with Al2O3, followed by application of silane layer, produced high bond strength after composite or repair aging.

Clinical cases of implant-supported fixed dental prosthesis using modified lingual screw system (T-screw system) / 대한치과보철학회지

The implant prosthesis can be divided into the screw retained prosthesis and cement retained prosthesis. Each type has advantages as well as disadvantages which is unfavorable to maintain the implants. To overcome these drawbacks, T-screw system was developed. T-screw system which utilizes a lingual direction of the screw to retain the implant prosthesis, has advantages of retrievability of the prosthesis, passive fit, and possibility to form esthetic and functional occlusal surface. The prior prosthesis which utilized horizontal screws had difficulty in fabrication especially in the case of multiple units, and also limited use with all-ceramic prosthesis. In this case, fabricating the implant prosthesis by using the T-screw system showed superior results in easy maintenance, esthetics, and also functions. In addition, we are to report the method of using the T-screw system in implant prosthesis, such as multiple units of implant prosthesis and all ceramic prosthesis.

Does MTA affect fiber post retention in repaired cervical root canal perforations?

Abstract This study evaluated the effect of mineral trioxide aggregate (MTA) on the retention of fiber posts in repaired root canal perforations. Ten-millimeter post spaces were prepared in 60 endodontically treated bovine incisors. Root perforations were created in half of the root canals in the cervical area prior to being filled with white MTA-Angelus. Fiber posts were luted into the root canals with two self-adhesive (RelyX Unicem or Set) or self-etching (Panavia F) resin cements. The posts were submitted to a pull-out test, and the data were submitted to two-way ANOVA and Tukey's post hoc tests (α = 0.05). The fiber posts exhibited reduced retention in MTA-repaired root canal perforations, regardless of the type of resin cement that was used (p < 0.001). Self-adhesive resin cements provided higher bond strength values than Panavia F, while no difference was observed between RelyX Unicem and Set (p > 0.05). The presence of MTA in repaired root perforations negatively affected post retention. In addition, self-adhesive cements seemed to be the best option to lute fiber posts within a root canal in these cases.

Effect of the superficial treatment in the repair of silorane-based composite aged artificially / Efeito do tratamento superficial no reparo de resina a base de silorano

Objective: To evaluate the effects of different surface treatments, in repair bond strength of an aged silorane-based composite. Methods: Specimens were made of a silorane-based composite (P90, 3M/ESPE), aged with thermal-cycling (10,000 cycles; 5-55ºC) and randomly submitted to different surface treatments (each group n = 24): control group (no repair); group 1 (only application of P90 adhesive); group 2 (diamond bur asperization + P90 adhesive); group 3 (aluminum oxide sandblasting + P90 adhesive) and group 4 (asperization + sandblasting + P90 adhesive). Then, the specimens were repaired with the same silorane-based composite and each group randomly subdivided into 2 subgroups: stored in distilled water at 37 °C for 7 days or submitted to thermal-cycling (5,000 cycles). After aging, the tensile test was carried out. The data was submitted to 2-way analysis of variance (2-way ANOVA). Results: The repaired groups aged with oven storage for 7 days did not statistically differ (p>0.05) from the corresponding groups aged with thermal-cycling. The bond strength of the specimens was significantly influenced by the superficial treatment (p<0.01). The highest values of tensile bond strength were found in groups 3 (20.76 ± 4.51 MPa) and 4 (20.67± 3.96 MPa), regardless of aging and repair. Conclusion: The repair of silorane-based composite showed to be stable after aging, and the superficial treatment with aluminum oxide sandblasting was the most effective.

Objetivo: Avaliar o efeito de diferentes tratamentos de superfície, na resistência de união de reparo em um compósito à base de silorano envelhecido. Métodos: Foram confeccionados espécimes de compósito a base de silorano (P90, 3M/ESPE), envelhecidos com termociclagem (10.000 ciclos, 5-55ºC) e aleatoriamente submetidos a diferentes tratamentos de superfície (cada grupo n= 24): grupo controle (sem reparo); grupo 1 (só aplicação do adesivo do P90); grupo 2 (asperização com ponta diamantada + adesivo do P90); grupo 3 (jateamento com óxido de alumínio + adesivo do P90) e grupo 4 (asperização e jateamento + adesivo do P90). Em seguida, os espécimes foram reparados com o mesmo compósito de silorano e cada grupo subdivididos aleatoriamente em 2 subgrupos: armazenados em água destilada à 37 °C por 7 dias ou submetidos termociclagem (5.000 ciclos). Após o envelhecimento, foi realizado o teste de tração. Os dados foram submetidos à análise de variância a dois fatores (ANOVA 2-way). Resultados: Os grupos reparados que foram submetidos ao envelhecimento de 7 dias em estufa não diferiram estatisticamente (p>0,05) dos grupos correspondentes envelhecidos com termociclagem. A resistência de união dos espécimes foi significativamente influenciada pelo tratamento superficial (p<0,01). Os maiores valores de resistência à tração foram encontrados nos grupos 3 (20,76 ± 4,51 MPa) e 4 (20,67± 3,96 MPa), independente do envelhecimento ou do reparo. Conclusão: O reparo de compósito à base de silorano se mostrou estável após envelhecimento e o tratamento superficial com jateamento de óxido de alumínio foi o mais efetivo.

Alternativa terapéutica en la discromía de un diente con distrofia pulpar por fuerzas ortodóncicas: presentación de caso / Therapeutic alternative for the decoloration of a tooth with pulp dystrophy caused by orthodontic forces: a case report

FUNDAMENTO: las fuerzas ortodóncicas excesivas pueden producir distrofias pulpares al modificar el sistema neuro-vascular de la pulpa. La necrosis de este tejido es la causa más conocida de alteración de color de los dientes. El tratamiento endodóntico y el blanqueamiento convencionales en estos casos se ven comprometidos cuando se desarrolla, además, una degeneración cálcica pulpar. OBJETIVO: mostrar una alternativa terapéutica a la discromía por necrosis pulpar de un diente con calcificación total de la pulpa. Caso clinico: se presenta una paciente de 18 años de edad con calcificación total de la pulpa posterior a un tratamiento ortodóncico y discromía en tercio cervical de corona del incisivo central superior derecho. CONCLUSIONS: se realizó tratamiento restaurador con carilla vestibular de composite fotocurable, logrando resultados estéticos satisfactorios.

BACKGROUND: excessive orthodontic forces may cause pulp dystrophies since they modify the pulp neuro vascular system. Necrosis of this pulp tissue is the most known cause of teeth color changes. Conventional endodontic treatment and bleaching are compromised in these cases whenever pulp calcification is developed. OBJECTIVE: to show an alternative therapy for dental discoloration due to pulpal necrosis in a tooth with pulp calcification. CLINICAL CASE: a eighteen year-old female is reported with pulp calcification following an orthodontic treatment and tooth discoloration in cervical third of a maxillary central right incisor. CONCLUSIONS: a restorative treatment with visible light cure composite veneer was performed, achieving satisfactory aesthetic results.