The stress distribution of a primary molar tooth restored with stainless steel crown using different luting cements.

BACKGROUND: The aim of this study is to evaluate the stress distributions of a primary molar tooth restored with a stainless steel crown (SSC) using resin and glass ionomer luting cements by Finite Element Analysis (FEA). METHODS: Original DICOM data of a primary molar was used to create a 3D model. One model was prepared as a tooth model with SSC. A 30 µm cement layer was used in model. Two different luting cements were tested in the study: self-cure adhesive resin cement, and glass ionomer cement. Vertical and oblique loads of 330 N were applied to simulate maximum bite force and lateral forces in the occlusal contact areas of the models. Maximum von Mises stress values in the models were evaluated as MPa. RESULTS: The maximum von Mises stress value was observed in the force application and general occlusal contact areas for all models. The maximum von Mises stress values were higher in the tooth model with SSC using self-cure adhesive resin cement (478.09 MPa and 214.62 MPa) than in the tooth model with SSC using glass ionomer cement (220.06 MPa and 198.72 MPa) in both vertical and oblique loading, respectively. CONCLUSIONS: Depending on the magnitude of the bite force on the SSC, fracture of the luting cement materials could occur if the stress exceeds the endurance limit of the luting cement. Cementation with glass ionomer cement may help to reduce stress levels in SSC restorations of primary molars in children.

Systematic review and network meta-analysis of restorative therapy and adhesive strategies in root caries lesions.

AIM: This systematic review and network meta-analysis (NMA) aimed to establish a clinically relevant hierarchy of the different adhesive and/or restorative approaches to restore cavitated root caries lesions through the synthesis of available evidence. MATERIALS AND METHODS: A systematic search was conducted in Medline/Web of Science/Embase/ Cochrane Library/Scopus/grey literature. RCTs investigating ≥2 restorative strategies (restorative /adhesive materials) for root caries lesions in adult patients were included. Risk of bias within studies was assessed (Cochrane_RoB-2) and the primary outcome was survival rate of restorations at different follow-up times (6-/12-/24-months). Network meta-analyses were conducted using a random effects model stratified by follow-up times. I2-statistics assessed the ratio of true to total variance in the observed effects. All available combinations of adhesives (1-SE: one-step self-etch; 2-3ER: two-/three-step etch-and-rinse) and restorative materials (conventional composite (CC) as well as conventional and resin-modified glass ionomer cements (GIC, RMGIC)) were included. Risk of bias across studies and confidence in NMA (CINeMA) were assessed. RESULTS: 547 studies were identified and nine were eligible for the NMA. In total, 1263 root caries lesions have been restored in 473 patients in the included clinical trials. Patients involved were either healthy (n = 6 trials), living in nursing homes (n = 1 trial) or received head-and-neck radiotherapy (n = 2 trials). There was statistically weak evidence to favour either of material/material combination regarding the survival rate. A tendency for higher survival rate (24-months) was observed for 2-3ER/CC (OR24mths 2.65; 95%CI=1.45/4.84) as well as RMGIC (OR24mths 2.05; 95%CI=1.17/3.61) compared to GIC. These findings were though not statistically significant and confidence of the NMA was low. CONCLUSION: An evidence-based choice of restorative strategy for managing cavitated root caries lesions is currently impossible. There is a clear need for more standardised, well-designed RCTs evaluating the retention rate of root caries restoration approaches.

Influence of collar height of definitive restoration and type of luting cement on the amount of residual cement in implant restorations: A clinical study.

STATEMENT OF PROBLEM: Residual cement in the peri-implant sulcus may cause peri-implant mucositis, which can lead to peri-implantitis. Clinical studies comparing the role of the collar height of the definitive restoration and the type of cement used for luting the prosthesis in the amount of residual cement are lacking. PURPOSE: The purpose of this clinical study was to determine the volume of residual cement left undetected in the peri-implant sulcus by an implant prosthesis with 3 different collar heights and 3 luting cements. MATERIAL AND METHODS: Participants with single implants in the premolar region were divided into 3 groups of 10 according to the distance from the peri-implant soft tissue crest to the implant platform: group low collar (sulcus depth <2 mm), group medium collar (2-4 mm), and group high collar (>4 mm). A metal-ceramic crown with an occlusal opening was fabricated on a straight titanium abutment, which facilitated removal of the crown along with the abutment after cementation. The implant luting cements used were composite resin cement (RelyX U200), Type I glass ionomer cement (GC Gold Label 1), and zinc oxide noneugenol interim luting cement (RelyX Temp NE). The modified crown was cemented with 1 cement each during the impression, bisque evaluation, and definitive crown cementation appointments. The crown was retrieved, and the residual cement collected during each appointment. The measurements obtained were statistically analyzed with general linear model analysis followed by post hoc testing using the Bonferroni test (α=.05). RESULTS: Mean volume of the residual excess cement (mm3) formed in group low collar was 0.33 ±0.17, 0.26 ±0.17, and 0.08 ±0.08 for subgroups Resin, GIC, and ZNE, respectively. In group medium collar, it was 1.18 ±0.31, 1.08 ±0.3, and 0.61 ±0.32; and in group high collar, it was 2.33 ±0.31, 2.1 ±0.74, and 1.31 ±0.56 for the same subgroup, respectively. There was a statistically significant difference in the formation of REC between the collar height groups (P<.001). Among the luting cements, zinc oxide noneugenol cement produced significantly lower residual cement compared with the other 2 cements, and there was no statistically significant difference between the glass ionomer and resin cements (P>.05). CONCLUSIONS: The collar height of the definitive restoration and the type of luting cement play significant roles in the formation of residual cement in fixed implant-supported restorations.

Influence of autoclave sterilization on bond strength between zirconia frameworks and Ti-base abutments using different resin cements.

STATEMENT OF PROBLEM: Zirconia frameworks luted on titanium bases have been increasingly used for implant-supported prostheses. A reliable bond strength between the framework and the base is a key factor for clinical success. Autoclaving of the abutments before clinical use has been strongly suggested since abutments have been classified as class II medical devices. However, comprehensive knowledge on the susceptibility of the composite resin luting agents' adhesion to autoclave sterilization is lacking. PURPOSE: The purpose of this in vitro study was to assess the bond strength between zirconia frameworks and titanium bases using different composite resin luting agents with and without thermocycling and autoclaving. MATERIAL AND METHODS: A total of 200 titanium implants were copy milled and 200 zirconia frameworks (Cercon) were generated by computer-aided design and computer-aided manufacturing (CAD-CAM). They were adhesively luted using Multilink Hybrid Abutment (MHA), Panavia F2.0 (PF2), Panavia V5 (PV5), RelyX Ultimate (RXU), or Panavia SA Cement Plus (PSA). Autoclaving (134 °C, 0.21 MPa, 5.5 minutes) and thermocycling (3000 cycles, 5 °C and 55 °C) were performed. The push out bond strength was tested at a crosshead speed of 1 mm/min. Statistical analysis was performed by using the Mann-Whitney U test (α=.05) and the family-wise error rate method. RESULTS: Median bond strength values (interquartile range) after autoclaving and thermocycling ranged between 33.7 (26.7-41.8) MPa for MHA and 7.6 (7.3-8.5) MPa for PF2. MHA showed significantly higher values than all other composite resin luting agents regardless of thermocycling or autoclaving. PV5 showed equal or higher bond strength values than PSA, RXU, and PF2. Autoclaving had no significant influence on MHA or PV5, but had a negative effect on PSA and RXU. The family-wise error rate method showed that both the composite resin luting agent and autoclave sterilization had an overall influence on bond strength. CONCLUSIONS: MHA and PV5 were not significantly influenced by autoclaving and showed acceptable bond strength values. Because MHA showed significantly higher bond strength than all other materials and is released for autoclaving by the manufacturer, it is the first choice for extraoral bonding of zirconia frameworks to titanium bases. Manufacturers who state the indication of extraoral cementation of frameworks on titanium bases should also indicate whether their composite luting material is affected by autoclaving.

Comparison of 3- and 90-day bond strengths of 3 types of cement to nickel-chromium alloy.

The purpose of this in vitro study was to compare the 3- and 90-day bond strengths of 3 cements used for luting metal-ceramic crowns. Zinc phosphate cement (ZPC; SS White), resin-modified glass ionomer cement (RMGIC; Fuji Plus), and self-adhesive resin cement (SARC; RelyX U200) were assessed in 2 different treatment conditions (with and without microsandblasting of the alloy) and at 2 experimental times (3 days [E1] and 90 days [E2] after cementation). The buccal surfaces of 84 bovine teeth were ground until the dentin was exposed, and 84 nickel-chromium alloy plates cast from a resin model were cemented to the dentin surfaces with 1 of the 3 cements (n = 28). In half of the specimens of each group (n = 14), the bonding surfaces of the nickel-chromium plates received 6 seconds of microsandblasting with 45-µm aluminum oxide particles prior to cementation. The compressive shear bond strengths of the specimens were evaluated in a universal testing machine at E1 and E2 (n = 7). The SARC group showed the greatest bond strength, followed by the RMGIC group, while the bond strength of the ZPC group was significantly lower (P < 0.01). For the RMGIC specimens subjected to microsandblasting, there was a statistically significant difference between the mean bond strengths at E1 and E2 (P = 0.040). All of the other cement and treatment groups showed statistically similar adhesion results at E1 and E2 (P > 0.05). The complementary test by Sidák revealed that the cements Fuji Plus and RelyX U200 showed higher values at E2 and were statistically similar to each other (P > 0.05). Although RMGIC specimens showed a lower initial bond strength than SARC specimens, the fact that the microsandblasted RMGIC subgroup was the only one that demonstrated a significant increase in bond strength with aging suggests that RMGIC can be a material of first choice because it also costs less than SARC.

Effects of dentinary contamination by endodontic irrigants on bonding strength of adhesive systems

This study aimed to evaluate if 2.5% sodium hypochlorite compromises the adhesion of bonding materials. The factors in the study were the irrigation solutions in two levels: 2.5% sodium hypochlorite and saline solution; and the adhesive systems used in three levels: three-step adhesive, universal adhesive, and two-step self-etch adhesive systems. The answer variable used was the microshear bond strength obtained through a universal testing machine and fracture mode. Six groups were obtained (n=10) : Etch-and-rinse/Saline (saline solution + 3-step adhesive system - Scotchbond Multipurpose, 3M ESPE); Universal/saline (saline solution + universal adhesive system ­ Prime&Bond,); Self-etch/saline (saline solution + 2-step self-etch adhesive systems - Clearfil SE Bond); Etch-and-rinse/Hypo (sodium hypochlorite 2,5% + 3-step adhesive system - Scotchbond Multiuso); Universal/Hypo (sodium hypochlorite 2,5% + universal adhesive system ­ Prime&Bond); Self-etch/Hypo (sodium hypochlorite 2,5% + 2-step self-etch adhesive system - Clearfil Se Bond). The specimens were obtained from 60 healthy bovine incisors. The crowns were separated from the roots, and the regularization of the buccal surface was performed. The groups received saline solution and 2.5% sodium hypochlorite for 30 minutes, respectively. A matrix of 1mm and 3mm oh height was stabilized by Scotch tape to obtain the resin sticks. Afterward, the bond strength test was performed in a universal testing machine at 1mm/min speed. The data were analyzed with normality Shapiro-Wilk, two-way ANOVA, and Tukey's tests (p<0.001). Etch-and-rinse and Self-etch adhesives presented the highest bond strength values after irrigation with saline solution and 2.5% sodium hypochlorite, respectively (P < 0.01). The irrigation with 2.5% sodium hypochlorite decreased the bond strength values of Etch-and-rinse and Universal (P < 0.01). On the other hand, 2.5% sodium hypochlorite improved the bond strength values of Self-etch (P < 0.01). In conclusion, 2.5% sodium hypochlorite negatively impacted the bond strength of Etch-and-rinse and Universal but improved the adhesion of Self-etch.

Evaluation of the dentinal tubule penetration of an endodontic bioceramic sealer after three final irrigation protocols

Introduction: This study aimed to evaluate the dentinal tubule penetration of an endodontic bioceramic sealer, Sealer Plus BC, after three final irrigation protocols. Methods: Thirty distobuccal roots of maxillary molars were selected. Root canal preparation was performed up to an #40.06 instrument (X1 Blue) under 2.5% sodium hypochlorite irrigation. Specimens were randomly divided into three groups (n=10), according to the final irrigation protocol: G-NaOCl (2.5% sodium hypochlorite + PUI), G-SS (0.9% saline solution + PUI) and G-H20 (Deionized water + PUI). After final irrigation protocols, all specimens were irrigated with phosphate buffer solution. Root canal obturation was performed using the single cone technique and Sealer Plus BC, stained with a specific fluorophore. Specimens were transversely sectioned and each root third was evaluated in a confocal scanning laser microscopy. Images obtained were analyzed for sealer penetration in the dentinal tubules. Results: Dentinal tubule penetration of Sealer Plus BC was not observed in any root third, regardless of the final irrigation protocol investigated. Conclusions: Sealer Plus BC dentinal tubule penetration was not observed after none of the protocols tested. Dentinal tubule penetrability of Sealer Plus BC may be related to other factors rather than the final irrigation protocol.

Resina Filtek Z250 XT precalentada como agente cementante de restauraciones indirectas / Preheated Filtek Z250 XT resin as a luting agent in indirect restorations

Introducción: Las restauraciones indirectas de resina son ampliamente empleadas para realizar tratamientos estéticos en dientes posteriores. Recientemente se ha propuesto el uso de resinas precalentadas como agentes de unión. Objetivo: Evaluar la resistencia a la tracción de restauraciones indirectas cementadas con una resina precalentada comparándola con un cemento de resina autoadhesivo y un cemento resinoso. Métodos: Las preparaciones dentarias se realizaron en 45 premolares con piedras diamantadas calibradas. Las muestras se dividieron aleatoriamente en tres conjuntos (n = 15) según los grupos experimentales: grupo 1 (resina precalentada), grupo 2 (resina autoadhesiva) y grupo 3 (cemento de resinoso adhesivo). Las muestras fueron incluidas en acrílico autopolimerizable. Se realizaron restauraciones indirectas para cada muestra, las superficies internas fueron microarenadas y se aplicó silano antes de la cementación con los agentes de unión. La resistencia a la tracción se realizó utilizando una máquina universal de ensayos con una velocidad de cruceta de 5 mm/min. El análisis estadístico se llevó a cabo con ANOVA de un factor y la prueba post hoc de Tukey. Se adoptó un nivel de significancia de p < 0,05. Resultados: La resina Filtek Z250 XT precalentada a 60 °C durante 15 minutos tuvo una fuerza de resistencia a la tracción de 5,775 MPa, similar a RelyX Ultimate con 5,442 MPa (p > 0,05), ambos grupos poseen una fuerza de resistencia a la tracción significativamente mayor que RelyX U200 (3,430 MPa). Conclusiones: La resina precalentada (Filtek, Z250 XT) y el cemento resinoso (RelyX Ultimate) muestran las mismas propiedades de resistencia a la tracción cuando se usan como agentes adhesivos en restauraciones indirectas de resina(AU)

Introduction: Indirect resin restorations are widely used in the esthetic treatment of posterior teeth. Preheated resins have been recently proposed as luting agents. Objective: Evaluate the tensile bond strength of indirect restorations cemented with a preheated resin versus a self-adhesive resin cement and a resinous cement. Methods: Tooth preparation was conducted of 45 premolars using calibrated diamond-coated stones. The samples were randomly divided into three sets (n = 15) according to the following experimental groups: Group 1 (preheated resin), Group 2 (self-adhesive resin) and Group 3 (adhesive resinous cement), and soaked in self-polimerizable acrylic. Indirect restorations were performed for each sample. The inner surfaces were microsanded, and silane was applied before cementation with the luting agents. Tensile bond strength was verified with a universal testing machine at a crosshead speed of 5 mm/min. Statistical analysis was based on one-factor ANOVA and Tukey's post hoc test. A significance level of p < 0.05 was established. Results: The Filtek Z250 XT resin preheated at 60°C for 15 minutes displayed a tensile bond strength of 5.775 MPa, similar to RelyX Ultimate with 5.442 MPa (p > 0.05). Both groups displayed a significantly greater tensile bond strength than RelyX U200 (3.430 MPa). Conclusions: The preheated resin (Filtek Z250 XT) and the resinous cement (RelyX Ultimate) exhibit the same tensile bond strength properties when used as luting agents in indirect resin restorations(AU)

Coronas cementadas comparado con coronas atornilladas para pacientes con restauraciones fijas implantosoportadas / Cement-retained versus screw-retained crowns in patients with implant rehabilitation

RESUMEN: Introducción: Los implantes dentales se han transformado en una opción de tratamiento de suma relevancia para pacientes parcial o totalmente desdentados. El éxito del tratamiento puede verse afectado por la elección del tipo de retención de estos (cementada o atornillada). A pesar que ambas presentan ventajas, aún no existe consenso sobre el mejor tipo de retención para restauraciones fijas implantosoportadas. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos 14 revisiones sistemáticas que en conjunto incluyeron 43 estudios primarios, de los cuales cinco corresponden a ensayos aleatorizados. De estos, solamente dos ensayos responden a la pregunta de interés de manera directa. Concluimos que las coronas atornilladas podrían aumentar levemente el riesgo de pérdida de implante a largo plazo, podrían resultar en nula o poca diferencia en el riesgo de pérdida de implante a mediano plazo, reabsorción ósea y periimplantitis, pero la certeza de evidencia ha sido evaluada como baja. Por otro lado, no es posible establecer con claridad si las coronas cementadas disminuyen el riesgo de complicaciones estéticas y protésicas, ya que la certeza de la evidencia existente ha sido evaluada como muy baja.

ABSTRACT: Introduction: Dental implants have become a highly relevant treatment option for partially or totally edentulous patients. Implant retention systems (cemented or screwed) can influence the treatment success. Although both have advantages, there is still no consensus on the best type of retention for implant-supported fixed restorations. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified 14 systematic reviews including 43 primary studies overall, of which five were randomized trials. Of these, only two trials answer the question of interest. We concluded that screw-retained crowns may increase long-term implant loss, may make little or no difference in the risk of medium-term implant loss, bone resorption, and peri-implantitis, but the certainty of the evidence has been assessed as low. On the other hand, it is not possible to clearly establish whether cemented crowns reduce the risk of cosmetic and prosthetic complications, since the certainty of the evidence has been assessed as very low.

Recuento de Streptococcus mutans sobre restauraciones realizadas con adhesivo con y sin carga de nanopartículas de óxido de zinc y cobre / Streptococcus mutans count on restorations made with adhesive with and without loading zinc and copper oxide nanoparticles

Objetivo: Determinar las propiedades antimicrobianas de la incorporación de nanopartículas de óxido de zinc y cobre en un adhesivo de grabado y lavado total sobre Streptococcus mutans en pacientes con restauraciones de resina compuesta confeccionadas con adhesivo cargado. Métodos: Estudio experimental, randomizado, la muestra estuvo conformada por 25 pacientes, de ambos sexos, pertenecientes al posgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Chile, en los cuales se confirmó presencia de Streptococcus mutans en saliva. Se confeccionaron restauraciones de resina compuesta oclusales, en premolares superiores con indicación de exodoncia por el tratamiento de ortodoncia, con adhesivo cargado (cuya composición fue 5/0,2 por ciento ZnO y Cu, respectivamente) y control (sin presencia de nanopartículas en su composición), según el listado de aleatorización. Se tomaron muestras microbiológicas en tres tiempos con la técnica de la cubeta (antes, 1 semana y 4 semanas posterior a la confección de las restauraciones). Se obtuvieron, aislaron e identificaron colonias de Streptococcus mutans a partir de las muestras obtenidas. Se usó el test de Mann-Whitney mediante el paquete estadístico SPSS v.21 Resultados: El promedio del recuento de UFC de Streptococcus mutans en el grupo experimental fue mayor posterior a la confección de las restauraciones de resina compuesta. Los resultados de la identificación molecular por PCR demuestran la presencia de Streptococcus mutans en 20 de 25 muestras. Conclusiones: No existen diferencias en el recuento de Streptococcus mutans antes y después de la aplicación del adhesivo sobre las restauraciones de resina compuesta(AU)

Objective: To determine the antimicrobial properties of the incorporation of zinc and copper oxide nanoparticles in an etching and total wash adhesive on Streptococcus mutans in patients with composite resin restorations made with loaded adhesive. Methods: Experimental and randomized trial, the sample were 25 patients, of both sexes, belonging to the FOUCH Orthodontic postgraduate program, in whom the presence of Streptococcus mutans in saliva was confirmed. Occlusal composite resin restorations were made in upper premolars with indication of extraction by orthodontic treatment, with loaded adhesive (whose composition is 5 / 0.2% ZnO and Cu respectively) and control (without the presence of nanoparticles in their composition), according to the scrambling listing. Microbiological samples were taken in three stages with the cuvette technique (before, 1 week and 4 weeks after the restoration was made). Colonies of Streptococcus mutans were obtained, isolated and identified from the samples obtained. The statistical analysis used the SPSS v.21 software, the data was analyzed by Mann Whitney test Results: The average CFU count of Streptococcus mutans in the experimental group (adhesive modified with zinc oxide and copper nanoparticles) was higher after the fabrication of composite resin restorations. The results of molecular identification by PCR demonstrate the presence of Streptococcus mutans in 20 of 25 samples. Conclusions: There are no differences in the count of Streptococcus mutans before and after the application of the adhesive on the composite resin restorations(AU)

Efecto antimicrobiano sobre Streptococcus mutans de sistema adhesivo con nanopartículas de óxido de zinc y cobre / Antimicrobial effect against Streptococcus mutans of an adhesive system with copper and zinc oxide nanoparticles

Objetivo: Determinar las propiedades antimicrobianas de la incorporación de nanopartículas de óxido de zinc y cobre en un adhesivo de grabado y lavado total sobre Streptococcus mutans en pacientes con restauraciones de resina compuesta confeccionadas con adhesivo cargado. Métodos: Este estudio clínico randomizado, participaron 25 pacientes, de ambos sexos, pertenecientes al posgrado de Ortodoncia de la Facultad de Odontología de la Universidad de Chile, en los cuales se confirmó presencia de Streptococcus mutans en saliva. Se confeccionaron restauraciones de resina compuesta oclusales, en premolares superiores con indicación de exodoncia por el tratamiento de ortodoncia, con adhesivo cargado (cuya composición es 5 / 0.2 por ciento ZnO y Cu respectivamente) y control (sin presencia de nanopartículas en su composición), según el listado de aleatorización. Se tomaron muestras microbiológicas en tres tiempos con la Técnica de la cubeta (antes, 1 semana y 4 semanas posterior a la confección de las restauraciones). Se obtuvieron, aislaron e identificaron colonias de Streptococcus mutans a partir de las muestras obtenidas. Los datos fueron analizados por el test de Mann Whittney. Resultados: El promedio del recuento de UFC (unidades formadoras de colonias) de Streptococcus mutans en el grupo experimental fue mayor posterior a la confección de las restauraciones de resina compuesta.Los resultados de la identificación molecular por PCR demuestran la presencia de Streptococcus mutans en 20 de 25 muestras. Conclusiones: No existen diferencias en el recuento de Streptococcus mutans antes y después de la aplicación del adhesivo sobre las restauraciones de resina compuesta(AU)

Objective: Determine the antimicrobial properties of the incorporation of copper and zinc oxide nanoparticles into a total rinse and etch adhesive against Streptococcus mutans in patients with composite resin restorations made with loaded adhesive. Methods: A randomized clinical study was conducted of 25 patients of both sexes from the orthodontics graduate course taught at the Dental School of the University of Chile, in whom the presence of Streptococcus mutans was confirmed in saliva. Occlusal composite resin restorations were performed in upper premolars with exodontia indicated as part of the orthodontic treatment, using loaded adhesive (composition 5 / 0.2 percent ZnO and Cu, respectively) and control (without nanoparticles in its composition), according to the randomization list. Microbiological samples were taken at three moments applying the tray technique (before, 1 week after and 4 weeks after the restorations). Streptococcus mutans were obtained, isolated and identified from the samples taken. Data analysis was based on the Mann-Whitney test. Results: Mean Streptococcus mutans CFU count in the experimental group was higher after the composite resin restorations were made. Results of PCR molecular identification show the presence of Streptococcus mutans in 20 of 25 samples. Conclusions: No differences were found in the Streptococcus mutans count before and after application of the adhesive over the composite resin restorations(AU)

Efecto antibacteriano de los selladores endodónticos en los conductos radiculares / Antibacterial effect of endodontic sealers in root canals

RESUMEN Introducción: Los selladores endodónticos desempeñan un papel crucial en la obturación, dado que dichos materiales, no solo actúan en el momento de su aplicación, sino que continúan haciéndolo con posterioridad, protegiendo al periodonto apical contra los organismos microbianos presentes. Precisamente, una de las propiedades deseadas en los selladores endodónticos es que posean acción antimicrobiana, para eliminar las bacterias remanentes después de la irrigación e instrumentación. Objetivo: Realizar una revisión sistemática del efecto antibacteriano de diferentes selladores endodónticos más utilizados en odontología contra Enterococcus faecalis (E. faecalis). Métodos: Esta revisión sistemática se llevó a cabo siguiendo los lineamientos PRISMA. La búsqueda se realizó en las bases de datos PubMed y Science Direct. Se revisaron los artículos de estudios antimicrobianos in vitro de selladores endodónticos y se excluyeron aquellos de fuente secundaria, como los de revisión de la literatura, así como artículos sobre cementos para otros usos. Desarrollo: Los cementos a base de hidróxido de calcio, resina o biocerámicos son biocompatibles y presentan algún porcentaje de actividad antimicrobiana; sin embargo, se puede apreciar que existe variabilidad en los resultados obtenidos en los estudios incluidos en la revisión, debido al uso de condiciones diferentes para la evaluación antibacteriana, excepto en los selladores endodónticos a base de silicona, los cuales tuvieron, de forma consistente, un efecto antibacterial nulo contra E. faecalis. Conclusión: De acuerdo a la bibliografía revisada, los selladores AH Plus, AH 26, TotalFill, BC Sealer y MTA Fillapex exhibieron efecto antimicrobiano, sin embargo, algunos de ellos mostraron escasa actividad contra E. faecalis(AU)

ABSTRACT Introduction: Endodontic sealers play a crucial role in sealing, for they not only act at the moment of their application, but continue to do so later, protecting the apical periodontium against microbial organisms. One of the properties desired in endodontic sealers is precisely their antimicrobial action against bacteria remaining after irrigation and instrumentation. Objective: Carry out a systematic review about the antibacterial effect of the endodontic sealers most commonly used in dental practice against Enterococcus faecalis (E. faecalis). Methods: The systematic review was based on PRISMA guidelines. The search was conducted in the databases PubMed and Science Direct. Papers were reviewed which dealt with in vitro antimicrobial studies about endodontic sealers, excluding secondary sources such as literature reviews and papers about cements used for other purposes. Discussion: Cements based on calcium hydroxide, resin or bioceramic are biocompatible and display some percentage of antimicrobial activity. However, variability was observed in the results obtained by the studies in the review, due to the use of different conditions for antibacterial evaluation, except for silicone-based endodontic sealers, which consistently displayed no antibacterial activity against E. faecalis. Conclusion: According to the bibliography reviewed, the sealers AH Plus, AH 26, TotalFill, BC Sealer and MTA Fillapex had an antimicrobial effect. However, some of them displayed scant activity against E. faecalis(AU)

Tratamiento Rehabilitador Estético-Oclusal con Resinas Compuestas en una Paciente con Mordida Profunda y Desgaste Severo / Aesthetic-Occlusal Rehabilitation Treatment with Composite Resins in a Patient with Deep Bite and Dental Wear

RESUMEN: La rehabilitación oral tradicional del paciente con mordida profunda y braquifacial puede ser muy compleja e invasiva, sin embargo, podría involucrar muchas especialidades para su resolución ideal. Un análisis integral estético-oclusal es necesario antes de empezar el tratamiento para hacer propuestas con el menor costo biológico, de tiempo y económico. La odontología adhesiva permite una propuesta aditiva y no invasiva como un tratamiento de mediano plazo o transitorio. Este artículo presenta un caso de una paciente de 46años de edad con mordida profunda anterior y desgaste dental severo en las caras palatinas de los dientes antero-superiores, sin disfunción temporomandibular, ni compromisos sistémicos. Se destaca la rehabilitación estética- oclusal con el mínimo compromiso biológico (ultra-conservadora), mediante restauraciones adhesivas semi-indirectas de resina compuesta con acompañamiento de 12meses. Esta propuesta rehabilitadora con resinas compuestas representa una alternativa de tratamiento para el manejo del paciente con mordida profunda anterior. El control a un año de tratamiento demostró que se siguió una secuencia y resolución que aseguró los principios de la rehabilitación oral, al mismo tiempo, se procedió de la manera menos invasiva posible.

ABSTRACT: The traditional oral rehabilitation of the patient with deep bite and brachifacial can be very complex and invasive, however, a number of treatments could be considered to improve rehabilitation. A comprehensive aesthetic-occlusal analysis is necessary prior to starting treatment in order to consider the best procedure, time involved, and economic cost. Adhesive dentistry allows an additive and non-invasive proposal as a medium-term or transitory treatment. A case of a 46-year-old patient is presented, with anterior deep bite and severe dental wear on palatal surfaces of the antero-superior teeth, without temporomandibular dysfunction, or systemic compromises. The objective was to emphasize the aesthetic and occlusal rehabilitation with the least biological commitment (ultraconservative), through semi-indirect adhesive restorations of composite resin with 12 months follow-up. This restorative proposal with composite resins represents an alternative treatment for patient management with anterior deep bite. Control at one year of treatment showed that a sequence and resolution was followed, that ensured adequate oral rehabilitation in the least invasive manner possible.

Comparación in vitro del espesor y homogeneidad de la capa de cementación en carillas indirectas, realizado con resina fluida vs cemento de resina fotodependiente / Comparison of thickness and homogeneity of thecementationlayer in indirectveneers, madewith fluidresin vs. light-cure resincement: in vitro study

Resumen Objetivo: Comparar el grosor y homogeneidad de la capa de cementación entre un cemento de resina fotodependiente y una resina fluida. Materiales y métodos: Para la obtención de la muestra se talló la preparación en un diente de marfilina, el cual fue escaneado y luego replicado 92 veces en un polímero ABS. La muestra se dividió en 2 grupos con 46 muestras cada uno. Se realizó la cementación de las carillas con resina fluida Tetric N-Flow en el grupo G1, y con cemento de resina fotodependiente VariolinkEsthetic en el grupo G2. Cada muestra fue previamente lavada con alcohol de 70°, luego secada y se aplicó una capa de adhesivo TetricN-Bond. Se utilizó presión digital para lograr el asentamiento final de las carillas. Finalmente se realizó un corte medial y uno paramedial para obtener muestras de 2 mm aproximadamente, las cuales se observaron y midieron en un microscopio óptico. Resultados: El promedio de grosor para Tetric N-Flow fue de 119μm en incisal, 113μm en medio y 107μm en cervical. Para VariolinkEsthetic el promedio fue de 117μm, 112μm y 110μm en incisal, medio y cervical respectivamente. La homogeneidad fue de un 93,3% para G1 y 91,3% para G2. Conclusión: No existe diferencia significativa en el grosor y homogeneidad de la capa de cementación realizado con resina fluida y con cemento de resina fotodependiente.

Abstract Objective: Compare the thickness and homogeneity of the cementing layer between a light-cure resin cementand a flowable resin. Materials and methods: To obtain the sample, the preparation was carved in a replica of tooth 1.1 (EWL modelteeth, Kavo), which was scanned and then replicated 92 times in an ABS polymerby 3D printing. The simple was divided into 2 groupswith 46 sample seach. The cementation of the veneres was performed with Tetric N-Flow flowable resin in the G1 group, and with Variolink Esthetic light-cure resin cement in the G2 group. Each simple was previously washed with 70° alcohol, then dried and a layer of Tetric N-Bond was applied. Digital pressure was used to achieve the final settlement of the veneers. Finally, a medial and a paramedial section were made to obtain approximately 2 mm thick samples. The cementation layer was observed with an optical microscope. Results: The average thickness for Tetric N-Flowwas 119μm in incisal, 113μm in medium and 107μm in cervical. For Variolink Esthetic the average was 117μm, 112μm and 110μm in incisal, middle and cervical respectively. The homogeneity was 93.3% for G1 and 91.3% for G2. Conclusion: There is no significant difference in the thickness and homogeneity of the cementing layer made with flowable resin and with light-cure resincement.

Comparación in vitro de la resistencia adhesiva de los sistemas adhesivos grabado y enjuague y autograbado / In vitro Comparison of the adhesive strength of the etch and rinse adhesive systems and self etching

Resumen El propósito del estudio fue comparar in vitro la resistencia adhesiva de los sistemas Etch and rinse (grabado y enjuague), 4ta y 5ta generación; y los sistemas Self Etch (autograbado), 6ta y 7ma generación. Se realizó un estudio descriptivo, comparativo. Se utilizaron 20 terceros molares extraídos por motivos ortodóncico y profilácticos. Los cuales fueron cortados por la mitad y se obtuvo 40 muestras, en forma aleatoria los dientes fueron divididos en cuatro grupos, 10 con 4ta generación, 10 con 5ta, 10 con 6ta y 10 con 7ma. Se realizó una prueba de tracción vertical medida en kilogramos fuerza, para luego ser transformados a megapascales (Mpa). Las resinas de 4ta generación obtuvieron una resistencia adhesiva de 29,9 Mpa, las de 5ta una resistencia de 16,9 Mpa, la de 6ta una resistencia de 27,5 Mpa y las de 7ma generación una resistencia de 11,0 Mpa. Los resultados se sometieron a pruebas de normalidad mediante la prueba de Shapiro Wilk, y que fueron analizados mediante el ANOVA de un factor, y se encontró diferencias estadísticamente significativas entre los cuatro grupos de estudio con un valor p de 0,001. Se concluye que el sistema adhesivo de 4ta generación clasificado como Etch and Rinse presentó mejor resistencia adhesiva, seguido del adhesivo de 6ta generación clasificado como Self Etch.

Abstract The purpose of the study was to compare in vitro the adhesive strength of the Etch and Rinse systems of the 4th and 5th generation; and Self Etch systems of the 6th and 7th generation. A descriptive, comparative study was carried out. Twenty third molars were used for this study, (these molars were extracted for orthodontic and prophylactic purposes). Each teeth were cut into two pieces obtaining 40 pieces in total, then they were chosen randomly of which 10 pieces were cut with the 4th generation adhesive strength, 10 with the 5th generation, 10with the 6th generation and 10th with the 7th generation of the adhesive. A vertical traction test was performed, measured in kilograms force, and then transformed into megapascals (Mpa). The 4th generation resins obtained an adhesive resistance of 29.9 Mpa, the 5th generation resins obtained a resistance of 16.9 Mpa, the 6th generation obtained a resistance of 27.5 Mpa and the 7th generation obtained a resistance of 11.0 Mpa. The results were subjected to normality tests using the Shapiro Wilk test. These results were analyzed using the oneway ANOVA, finding statistically significant differences between the four study groups with a p-value of 0.001. As a conclusion; the 4th generation adhesive system classified as Etch and Rinse showed better adhesive strength, followed by the 6th generation adhesive system classified as Self Etch .

Bonding of universal adhesive system to enamel surrounding real-life carious cavities

Abstract: This study aimed to evaluate the bond strength of a universal adhesive system to enamel surrounding real-life carious cavities. Twenty-eight permanent molars (n = 7) with carious lesions in dentin were subjected to selective carious tissue removal to firm dentin and had their crowns sectioned longitudinally. A universal adhesive system (Single Bond Universal [SBU] used in either etch-and-rinse and self-etch strategies) was compared with an etch-and-rinse Adper Single Bond 2 (ASB) and a self-etch Clearfil SE Bond (CSE) adhesive systems (control systems). Adhesives were applied on the enamel, assumed demineralized, surrounding the cavity margins and on sound enamel (control substrate). Composite cylinders were built (0.72 mm2) and microshear bond strength (µSBS) test was performed after 24 h of water storage. The µSBS values (MPa) were analyzed using two-way ANOVA and Tukey's post hoc tests (α = 0.05). Bond strength values obtained in demineralized enamel surrounding carious cavity margins were significantly lower than that obtained in sound enamel (distant from carious cavity margins) (p = 0.035). The bonding strategy of the SBU did not influenced the bond strength values, which were higher than that obtained with ASB. CSE showed similar µSBS values to ASB and SBU in the self-etch mode. In conclusion, the bond strength to enamel assumed demineralized is lower than to sound enamel. The enamel surrounding carious cavities jeopardize the bonding of universal adhesive system. The bond strength of universal adhesive is similar, regardless to bonding strategy.

A randomized clinical trial of cavity liners after selective caries removal: one-year follow-up

Abstract Alternatives for the treatment of caries disease, such as minimally invasive approaches, have been developed in recent years. Objective: To carry out clinical and radiographic evaluations of three cavity liners after selective caries removal. Methodology: Thirty-six primary molars with deep occlusal caries lesions without pulp involvement (from children of both genders, aged between 5 and 8 years) were randomly divided into the following groups: calcium hydroxide cement (CHC) group; mineral trioxide aggregate (MTA) group and Portland cement with added zirconium oxide (PCZ) group. The following-up period was 6- and 12-month. The clinical and radiographic success rates were evaluated through chi-square test. The radiographic measurements were compared by ANOVA followed by Tukey's test (p<0.05). Results: Thirty-six patients were included, but thirty-four returned for 12-month follow-up. The overall success rate of the therapy for the three groups was 94.11% and no statistically significant differences occurred in the comparison among groups (p>0.05). Nineteen radiographs were selected to measure the dentin barrier thickness. The intragroup comparison presented a statistically significant increase of the dentin barrier for all groups, at 12-month follow-up. However, the MTA group showed increase of the dentin barrier, over time, 6- to 12-month follow-up. The intergroup comparison revealed no statistically significant differences (p>0.05). Conclusion: The clinical and radiographic data showed that all cavity liners provided effective treatment of primary teeth after selective caries removal.

Early histological, microbiological, radiological, and clinical response to cemented and screw-retained all-ceramic single crowns.

OBJECTIVES: To assess the early histological, microbiological, radiological, and clinical response to cemented and screw-retained all-ceramic single-tooth implant-supported reconstructions. MATERIALS AND METHODS: Patients with single-tooth implants were randomly allocated to receive a cemented lithium disilicate crown on a customized zirconia abutment (CEM) or a screw-retained crown with a directly veneered zirconia abutment (SCREW). At the screening visit, at crown insertion and at the 6-month follow-up, clinical parameters were measured at the implant and the contralateral tooth. Marginal bone levels, technical parameters, and esthetic outcomes were measured at the implants. At the 6-month follow-up, a microbiological test was performed and a soft tissue biopsy was harvested at the implants for histological analysis. Inflammatory cells and fibroblasts/-cytes were analyzed at the level of the sulcular epithelium, junctional epithelium, and connective tissue. The histological parameters were analyzed by means of a linear mixed model. RESULTS: Thirty-three patients completed the study, and implant and crown survival rates were 100% at 6 months. Histologically, the number of inflammatory cells tended to be higher in group CEM (p > 0.05). Moreover, significantly less inflammatory cells and fibroblasts/-cytes were found in the sulcular epithelium compared to the junctional epithelium and supracrestal connective tissue (p < 0.001). Four patients were tested positive for periodontal marker pathogens at the 6-month follow-up, and three of them belonged to group CEM. From crown insertion to the 6-month follow-up, median marginal bone levels changed only minimally and measured 0.31 and 0.32 mm in group CEM and 0.47 and 0.36 mm in group SCREW, respectively. Clinical and esthetic parameters remained stable over time and were comparable between natural teeth and implants as well as between the groups. CONCLUSIONS: Cemented reconstructions were associated with more inflammatory cells, and more patients were diagnosed with periodonto-pathogens. Both types of reconstructions resulted in similar radiological (marginal bone levels) and clinical outcomes (bleeding on probing and probing depth).

Retreatment Efficacy of Endodontic Bioceramic Sealers: A Review of the Literature / Eficacia del retratamiento de cementos endodónticos biocerámicos: Revisión de Literatura

Abstract The endodontic retreatment is a feasible solution when post-operative apical periodontitis persists or develops. The complete removal of the filling materials is important in order to ensure the unobstructed contact of the intracanal disinfectants with the microbes. As a new generation of bioceramic endodontic sealers has emerged, their removal efficacy from the root canal system during retreatment is a matter of concern among clinicians. The aim of this article is to provide a comprehensive review of the current literature on the retreatability of these novel obturating materials. A significant amount of bioceramic sealer remnants in the root canal walls was observed in all studies. Even though canal cleanliness could not be obtained at an ideal level, the re-establishment of the working length and patency can be considered manageable and comparable to other endodontic sealers.

Resumen El retratamiento endodóntico es una solución factible cuando la periodontitis apical post-operatoria persiste o se desarrolla. La eliminación completa de los materiales obturadores es importante para garantizar el contacto y acción de los desinfectantes e irrigantes endodónticos con los microorganismos persistentes. A medida que ha surgido una nueva generación de selladores endodónticos biocerámicos, su eficacia de eliminación del sistema de conductos radiculares durante el retratamiento es motivo de preocupación entre los profesionales. El objetivo de este artículo es proporcionar una revisión exhaustiva de la literatura actual sobre la influencia o posibles limitantes del uso de este tipo de cementos bioactivos durante el retratamiento endodóntico. Los estudios determinaron una cantidad significativa de restos de selladores biocerámicos en las paredes del conducto radicular. Aunque la limpieza del canal no se pudo obtener a un nivel "ideal", el restablecimiento de la longitud de trabajo y la permeabilidad se puede considerar manejable y comparable a otros selladores endodónticos.

Does ErbiumiYttrium-Aluminum-Garnet Laser to Enamel improve the Performance of Etch-and-rinse and Universal Adhesives?

AIM: This study aims to evaluate the effect of erbium: Yttrium-aluminum-garnet (Er:YAG) laser irradiation on the enamel microshear bond strength (µSBS), followed by the utilization of etch-and-rinse and universal adhesive systems. MATERIALS AND METHODS: A total of 32 molars were sectioned in the mesiodistal direction producing 64 samples that were randomized into two groups (n = 32): single bond 2 (SB2) (etch-and-rinse system; 3M), SB universal (SBU) (universal etching system; The SB2 and SBU groups were then divided into two subgroups (n = 16): (i) enamel was irradiated with an Er:YAG laser (λ = 2.94 µm, 60 mJ, 10 Hz), and (ii) enamel served as a control. The samples were restored with TPH3 (Dentsply), stored in artificial saliva for 24 hours, and subjected to a micro-shear test. RESULTS: Kruskal-Wallis (p < 0.05) and Mann-Whitney U tests indicated no significant differences in uSBS between the groups, and the fractures were predominately at the resin-enamel interface. CONCLUSION: The previous irradiation of enamel with Er:YAG laser does not interfere with the performance of simplified two-step etch-and-rinse and universal adhesive systems. CLINICAL SIGNIFICANCE: The increasing use of Er:YAG laser is important to evaluate the influence of this irradiation on the adhesion of restorative materials. Thus, to obtain the longevity of the restorative procedures, it is necessary to know the result of the association of the present adhesive systems to the irradiated substrate.