Comparative Evaluation of Bond Strength of Self-Etching and Total Etch Dental Adhesive Systems to Dentin of Deciduous and Permanent Teeth / Evaluación Comparativa de la Fuerza de Unión de los Sistemas de Adhesivo Dental Autograbado y Grabado Total para la Dentina de Dientes Deciduos y Permanentes

ABSTRACT: The aim of this study was to analyze the bond strength of total-etch and self-etch adhesive systems to dentin of primary and permanent teeth. Methods: Thirty sound naturally exfoliated primary molars deciduous teeth (DT) and thirty sound permanent bicuspids permanent teeth (PT) were randomly divided into six groups (n=10 per group) according to two commercial adhesive systems: Adper Single Bond 2; 3M ESPE (Total-etch) and Adper Easy Bond; 3M ESPE (selfetch and total-etch). Specimens submitted to cyclic loading in a universal Instron testing machine. Bond strength values (MPa) were analyzed by ANOVA test and Duncan post hoc test (a=0.05). Results: Mean values were higher in PT compared to DT. In deciduous teeth, no significantly differences observed. Total etch AdperTM Single Bond 2 showed significantly higher bond strength than self-etch AdperTM with additional acid etching in PT (p=0.031). Conclusion: Our findings suggest that the highest bond strength was found in dentin tissue of PT with total etch AdperTM employing the adhesive the Single Bond 2 of one step self-etch.

RESUMEN: El objetivo de este estudio fue analizar la fuerza de unión de los sistemas adhesivos de grabado total y autograbado a la dentina de los dientes primarios y permanentes. Métodos: treinta sonidos exfoliaron naturalmente los molares primarios dientes caducifolios (DT) y treinta sonidos. Los dientes permanentes de los premolares permanentes (PT) se dividieron aleatoriamente en seis grupos (n = 10 por grupo) de acuerdo con dos sistemas adhesivos comerciales: Adper Single Bond 2; 3M ESPE (Grabado total) y Adper Easy Bond; 3M ESPE (autograbado y grabado total). Muestras sometidas a carga cíclica en una máquina universal de pruebas Instron. Los valores de resistencia de la unión (MPa) se analizaron mediante la prueba ANOVA y la prueba post hoc de Duncan (a = 0.05). Resultados: Los valores medios fueron mayores en PT en comparación con DT. En dientes deciduos, no se observaron diferencias significativas. Total etch AdperTM Single Bond 2 mostró una fuerza de unión significativamente mayor que la autograbado AdperTM con grabado ácido adicional en PT (p = 0.031). Conclusión: Nuestros hallazgos sugieren que la mayor fuerza de unión se encontró en el tejido de dentina de PT con grabado total AdperTM empleando el adhesivo Single Bond 2 de autograbado de un solo paso.

Non-thermal plasma increase bond strength of zirconia to a resin cement / Plasma não-térmico aumenta a resistência de união da zircônia a um cimento resinoso

Objective: This study investigated the influence of different surface treatments on zirconia surface energy, roughness and microshear bond strength. Material and Methods: Forty eight slices of Yttriastabilized tetragonal zirconia polycrystal (Y-TZPVITA In-Ceram® YZ for inLab®) (6.4 x 3.2 x 1.6 mm) were divided into 3 groups according to the surface treatment (n = 16): YTZP_control -untreated; YTZP_plasma -surface treatment with non-thermal oxygen plasma; YTZP_primer - coating with ceramic primer. Surface energy (n = 6) was measured with a goniometer; and surface roughness (n = 10) was analyzed with a 3D profilometer were performed over zirconia surface. On the same specimens of surface roughness, on the treated zirconia's surface, resin cement (PANAVIA V5 - Kuraray Noritake Dental) was built up by inserting the resin cement into Tygon tubes (1 mm of internal diameter X 1 mm length). After 24h storage, microshear test was assessed. Data were analyzed by one-way ANOVA and Tukey posthoc test (p < 0.05). Results: Nonthermal oxygen plasma treated specimens exhibited higher statistically significant surface energy (p = 0.00) and bond strength (p = 0.00) when compared to control and primer groups. Roughness test (p = 0.897) could not detect statistical difference among the tested groups. Conclusion: Non-thermal oxygen plasma should be a suitable alternative for zirconia surface treatment prior to luting hence it improved microshear bond strength and provided higher surface energy without affecting surface roughness. (AU)

Objetivo: Este estudo investigou a influência de diferentes tratamentos de superfície na energia de superfície, rugosidade e resistência de união da zircônia. Material e Métodos: Quarenta e oito fatias de zircônia tetragonal policristalina estabilizada por ítria (Y-TZP - VITA InCeram® YZ for inLab®) (6,4 x 3,2 x 1,6 mm) foram divididas em 3 grupos de acordo com o tratamento de superfície (n = 16): YTZP_controle sem tratamento; YTZP_plasma - tratamento de superfície com plasma de oxigênio não térmico; YTZP_primer - aplicação de um primer cerâmico. A energia da superfície (n = 6) foi medida com o auxilio de um goniômetro; e a rugosidade superficial (n = 10) foi analisada com um perfilômetro 3D. Nos mesmos espécimes da rugosidade, prolongamentos de cimento resinoso (PANAVIA V5 - Kuraray Noritake Dental) foram construídos inserindo o cimento em micro túbulos de silicone (1mm de diâmetro interno de X 1 mm de comprimento). O teste de microcisalhamento foi realizado após 24h. Os dados foram analisados estatisticamente ANOVA um fator e teste auxiliar de Tukey (p < 0,05). Resultados: Os espécimes tratados com plasma de oxigênio apresentaram maiores valores de energia de superficie (p = 0,00) e resistência de união estatisticamente significante (p = 0,00) quando comparados aos grupos controle e do primer. A análise de rugosidade (p = 0,897) não detectou diferença estatística entre os grupos testados. Conclusão: O plasma não térmico pode ser uma alternativa para o tratamento de superfície de zircônia antes da cimentação, pois aumentou a resistência de união ao microcilsalhamento e proporcionou maior energia superficial sem afetar a rugosidade da superfície. (AU)

Estudo in vitro do nível de escoamento de cinco cimentos endodônticos: Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT / In vitro study of the flow rate of five root canal sealers: Endofill, AH Plus, MTA Fillapex, Sealer 26 and Pulp Canal Sealer EWT

Objetivo: o objetivo desse trabalho foi estudar, in vitro, o nível de escoamento dos cimentos Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT. Métodos: os cimentos foram manipulados de acordo com as recomendações dos fabricantes. A determinação do escoamento foi conseguida em conformidade com a especificação #57 da ADA (American Dental Association). Na comparação entre os grupos, foi realizada a ANOVA (análise de variância) e posterior teste de Tukey, com nível de confiança de 95%. Resultados: os resultados mostraram que o cimento MTA Fillapex apresentou o maior escoamento entre os cimentos estudados e o cimento AH Plus foi o único que apresentou escoamento estatisticamente significativo após 24 e 48 horas. Conclusão: concluiu-se que todos os cimentos avaliados estão em conformidade com a especificação #57 da ADA. No entanto, o cimento MTA Fillapex foi superior aos outros cimentos analisados, no que se refere ao poder de escoamento. O desempenho clínico do cimento obturador está diretamente relacionado à sua capacidade de penetrar nos túbulos dentinários e canais laterais; daí a importância do estudo do escoamento dos cimentos endodônticos.

Sistemas adesivos - classificação / Adhesives systems - classification

Os adesivos dentários são combinações de monômeros resinosos hidrofílicos e hidrofó- bicos, de diferentes pesos moleculares e solventes, que estabelecem ligação entre o material restaurador e a estrutura dentária após polimerização. Sistemas adesivos atuais são indicados para diversas aplicações odontológicas e classificados como condicionamento total (etch-and- -rinse) ou autocondicionamento (self-etching) e sua intenção de uso difere no número de etapas de aplicação e como eles interagem com as estruturas dentais naturais.

Dentin adhesives are combinations of hydrophilic and hydrophobic monomers, with different molecular weights and solvents that connect the restorative material to the tooth structure after polymerization. Current adhesive systems are suitable for various dental applications and classified as etch-and-rinse or self-etching. The purpose of their use differs according to the number of application steps and how they interact with the natural dental structures.

Influence of cementation and cement type on the fracture load testing methodology of anterior crowns made of different materials.

To evaluate the influence of cementation on fracture load of anterior crowns made of CAD/CAM-resin-blocks (ART), leucite-reinforced glass-ceramics (LRG), lithium disilicate ceramics (LIT), veneered zirconia (ZRO) and veneered alloy (DEG). Each crown group (n=15/subgroup) was cemented on the metal abutment as follows: i. using glass ionomer, ii. using self-adhesive resin cement, and iii. not cemented. Crowns were tested and analyzed with 2-way and 1-way ANOVA (Scheffé test), and Weibull statistics (p<0.05). Within LRG, self-adhesive cemented subgroup showed higher fracture load compared to other groups (p<0.001). Among DEG, lower results were measured for non-cemented crowns than for cemented (p<0.001). For ART, LIT and ZRO no influence of cementation was observed. For fracture load test methodology, metal ceramic crowns should be generally cemented. Glass-ceramic crowns should be cemented using adhesive cement. Cementation and cement type did not have an influence on the fracture load results for resin, zirconia or lithium disilicate crowns.

The role of cements in dental lant success, Part I.

Peri-implant disease can be the result of residual excess cement. While there is no ideal implant restorative cement, the clinician must be aware that the material selection for implant restorations should not be based on properties which are more suited to restoration of the natural dentition. More appropriate criteria would be those unique to implants and the specific challenges these medical devices bring to the restorative dentist.

Fractographic analyses of all-ceramic crowns: a study of 27 clinically fractured crowns.

OBJECTIVES: The use of all-ceramic restorations has been steadily increasing in the decades since the introduction of high-strength core ceramics as an alternative to metal cores. Even with high-strength ceramic cores, the crowns are susceptible to fractures during clinical function, probably the major concern associated with all-ceramic restorations. The aim of this study was to analyze fracture features of clinically fractured crowns in order to determine crack initiation sites and crack propagation paths. METHODS: Fractographic methods were used to analyze 27 all-ceramic full coverage crowns with alumina cores and feldspatic veneering ceramic. The fractured crowns were supplied by dentists in private and public practices with information of type of cement and time in function if available. RESULTS: The fractured crowns comprised 13 incisors, 3 premolars and 11 molars. The results revealed that all fractures initiated in the cervical margin of the crowns and usually from the approximal area close to the most coronally placed curvature of the margin. There was no statistically significant association between the cement used and time in function. SIGNIFICANCE: Fractography of clinically failed all-ceramic crowns can provide information on the fracture modes and design considerations. The findings are in contrast to fracture modes from in vitro tests. The results suggest that more clinically relevant in vitro test methods to study the durability of ceramic crowns should be developed.

Cementation: methods and materials. Part two.

This is a review of the literature of the last 21 years about cementing or luting indirect restorations to tooth structure. Recommendations are made as to the surface preparation of precious metals, non-precious metals, indirect composite materials, and all available porcelain materials including feldspathic, luecite reinforced, lithium di-silicate, slip cast aluminum oxide, densely sintered aluminum oxide, and zirconia prior to luting. Using data from a variety of sources, product categories of materials and various bonding materials and procedures are ranked according to their bond strength and durability.

Bonded molar tubes: a survey of their use by specialist orthodontists.

OBJECTIVE: To investigate the use of bonded molar tubes (BMTs) by specialist orthodontists. DESIGN: Prospective postal questionnaire. SETTING: Ireland. PARTICIPANTS: Registered members of the Orthodontic Society of Ireland. METHODS: A questionnaire was posted to registered members of the Orthodontic Society of Ireland. It investigated demographics, pattern of use, reasons for use and techniques for placement of BMTs. RESULTS: A 74% response rate was obtained. In more than 80% of cases, BMTs were used on first and second permanent molars by 52% and 33% of orthodontists respectively. BMT usage was adopted by 97% of respondents in the previous decade. Direct bonding was used by all for BMT placement. Etch times for molars, compared to other teeth, increased from 15 to 30 seconds by 51% of orthodontists. Of the respondents, 97% used light-cured adhesives and 17% used self-etching primers. Molar tube holders were preferred by 54% for placement. Only with a history of epilepsy, were bands preferred to BMTs. BMTs were regarded as more cost-effective than molar bands by 66% of responding clinicians. CONCLUSIONS: Specialist orthodontists preferred BMTs to bands on first permenent molars. Direct bonding was favoured using a 30-second etch, a light-cured primer and adhesive with specialized molar tube holders. BMTs were perceived to be more cost-effective than molar bands.

Extension for prevention: margin placement.

This article will review the concept of extension for prevention popularized by G.V. Black around the early 1900s. Concepts of extension and prevention have changed over the years with a more informed knowledge of the caries process, improved materials, cutting instruments, and techniques. The reasons for placement of the outline form relative to the tooth morphology, gingival tissue, relationship to adjacent teeth, and the choice of material will be described for all of the materials used in restorative dentistry. Research will be cited to support the scientific basis for outline form placement.

Considerations for proper selection of dental cements.

Selecting the proper cement for sufficient bond strength has become progressively complicated as the number of different materials for indirect restorations has increased. The success of any restoration is highly dependent on the proper cement being chosen and used. The function of the cement is not only to seal the restoration on the tooth but also, in some cases, to support the retention of the restoration. This ability to strengthen retention varies by the cement chosen by the clinician; therefore, careful consideration must precede cement selection.

Retrospective comparison of semipermanent and permanent cementation of implant-supported single crowns and FDPs with regard to the incidence of survival and complications.

PURPOSE: To retrospectively compare the fixation modalities semipermanent and permanent for all cemented single crowns and Fixed Dental Prostheses (FDPs) placed at the Department of Prosthodontics in the years 2002 to 2010 with regard to the incidence of survival and complications. MATERIALS AND METHODS: Two hundred forty-one patients (48.5% male, mean age 57.3 years) received 166 FDPs and 232 single crowns. A total of 50.6% of the FDPs and 54.7% of the single crowns were fixed using semipermanent cements. Aside from fixation, age, gender, type, location, and material of the suprastructures were assessed as possible factors affecting complications, namely de-cementation, chipping, framework, or abutment fracture. RESULTS: During an observation period of up to 6.6 years (mean 2.24 years; standard deviation 1.38), the survival rates were 96.4% and 100% for FDPs (semipermanent/permanent cementation), and 98.4% and 92.4% for single crowns (semipermanent/permanent). The success rates achieved, counting every complication, for the FDPs were 61.9% and 70.7% (semipermanent/permanent) and for single crowns were 75.6% and 77.1% (semipermanent/permanent). The cement used had a significant effect on loss of retention of the FDPs (p = .006), but no significant effect on the retention of the single crowns. Cementation procedure exhibited no significant impact on chipping for both FDPs and single crowns. The frequency of framework or abutment fractures was too low for further statistical analyses. CONCLUSION: Both semipermanent and permanent cementation of FDPs and single crowns resulted in high survival rates. Within the limitations of the study design, because of the amount of chairside aftercare required, implant-borne FDPs could be recommended for permanent cementation.

Survival and chipping of zirconia-based and metal-ceramic implant-supported single crowns.

PURPOSE: The objective of this retrospective study was to compare the incidence of chipping of implant-supported, all-ceramic, and metal-ceramic single crowns. MATERIAL AND METHODS: One hundred fifty-three patients (51.7% male, mean age 55.0 years) received 232 cemented implant-supported single crowns. One hundred and seventy-nine crowns had a metal framework (gold alloy) and 53 crowns were all-ceramic (zirconia framework and glass-ceramic veneer material). Age, gender, kind of cementation, and location of the restorations were assessed as possible factors affecting chipping. RESULTS: During the observation period of up to 5.8 years (mean 2.1 years; standard deviation 1.4), a total of 13 (24.5%) all-ceramic and 17 (9.5%) metal-ceramic crowns suffered from chipping, a difference that was statistically significant. A total of ten single crowns had to be remade resulting in survival of 86.8% (all-ceramic) and 98.3% (metal-ceramic). The other possible factors did not have a significant effect on the chipping. CONCLUSION: Chipping was found to be more frequent for all-ceramic implant-supported single crowns. If the reasons for the vulnerability of all-ceramic crowns remain unknown, implants with all-ceramic single crowns should generally be recommended with care.

Crown and bridge cements: clinical applications.

Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

Effect of cement type and water storage time on the push-out bond strength of a glass fiber post.

This study investigated the effects of the cement type and the water storage time on the push-out bond strength of a glass fiber post. Glass fiber posts (Fibrekor, Jeneric Pentron) were luted to post spaces using a self-cured resin cement (C&B Cement [CB]), a glass ionomer cement (Ketac Cem [KC]) or a resin-modified glass ionomer cement (GC FujiCEM [FC]) according to the manufacturers' instructions. For each luting agent, the specimens were exposed to one of the following water storage times (n=5): 1 day (T1), 7 days (T7), 90 days (T90) and 180 days (T180). Push-out tests were performed after the storage times. Control specimens were not exposed to water storage, but subjected to the push-out test 10 min after post cementation. Data (in MPa) were analyzed by Kruskal-Wallis and Dunn`s test (α=0.05). Cement type and water storage time had a significant effect (p<0.05) on the push-out bond strength. CB showed significantly higher values of retention (p<0.05) than KC and FC, irrespective of the water storage time. Water storage increased significantly the push-out bond strength in T7 and T90, regardless of the cement type (p<0.05). The results showed that fiber posts luted to post spaces with the self-cured resin cement exhibited the best bonding performance throughout the 180-day water storage period. All cements exhibited a tendency to increase the bond strength after 7 and 90 days of water storage, decreasing thereafter.