Responses of dental pulp cells to a less invasive bleaching technique applied to adhesive restored teeth

To assess the cytotoxicity of 35% hydrogen peroxide (HP) bleaching gel applied for 15 min to sound or restored teeth with two-step self-etching adhesive systems and composite resin. Materials and Methods: Sound and restored enamel/dentin disks were stored in water for 24 h or 6 months + thermocycling. The disks were adapted to artificial pulp chambers and placed in compartments containing culture medium. Immediately after bleaching, the culture medium in contact with dentin was applied for 1 h to previously cultured odontoblast-like MDPC-23 cells. Thereafter, cell viability (MTT assay) and morphology (SEM) were assessed. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). Results: In comparison to the negative control group (no treatment), no significant cell viability reduction occurred in those groups in which sound teeth were bleached. However, a significant decrease in cell viability was observed in the adhesive-restored bleached groups compared to negative control. No significant difference among bleached groups was observed with respect to the presence of restoration and storage time. Conclusion: The application of 35% HP bleaching gel to sound teeth for 15 min does not cause toxic effects in pulp cells. When this bleaching protocol was performed in adhesive-restored teeth, a significant toxic effect occurred.

Variáveis que afetam o procedimento de colagem direta ortodôntica: braquetes e materiais adesivos

Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.

Efeitos da aplicação de resina hidrofóbica sobre a resistência de união de adesivos autocondicionantes de frasco único

Introduction: It is known that self-etching adhesive systems can act as semi-permeable membranes. Objective: Evaluate the effects of additional layer of hydrophobic resin on the microtensile bond strength of self-etching one-bottle adhesives. Material and method: Sixty bovine incisors were used in this study. The facial enamel surfaces of the crowns were abraded with silicon carbide paper to expose flat, mid-coronal dentin surfaces. The following adhesives were used: Clearfil Tri S Bond (CTSB), AdheSE One (ADH) and One Coat  7.0 (OC). Each material was tested with and without applying an additional layer of hydrophobic material from the same manufacturer. Z-350 composite resin was inserted in three 1 mm increments. All adhesive restorative procedure was performed under simulated pulpal pressure and the microtensile test was performed immediately after curing the composite resin. Data were submitted to ANOVA and Tukey test (p < 0.05). Result: For all adhesives tested, the worst results were observed in groups which the additional layer of hydrophobic resin was not applied. Conclusion: The application of additional layer of hydrophobic material can improve the adhesion of self-etching all-in-one adhesive systems.

Hipersensibilidade dentinária cervical: em busca de um tratamento eficaz

The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.

Ethanol is inefficient to remove endodontic sealer residues of dentinal surface

Endodontic sealer residues on dentinal surface have negative effects on adhesion of adhesives system and/or can cause discoloration of the dental crown. Objective: To evaluate the efficacy of 95% ethanol in removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface. Material and methods: Thirty-two bovine incisor dental crown fragments (0.5 mm x 0.5 mm) were treated with 17% EDTA and 2.5% NaOCl. The specimens were divided into three experimental groups (n = 10): G1 (AH Plus), G2 (Epiphany SE) and G3 (Sealapex). In each group was applied a coating of one endodontic sealer type and were left undisturbed for 5 minutes. After this period, the specimens were cleaned with 95% ethanol. The control group was composed by two specimens that did not receive any sealer or cleaning treatment. The sealer residues persistence after cleaning with 95% ethanol was evaluated by scanning electron microscopy (x500) and a score system was applied. Data obtained were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Results: Moderate amount of endodontic sealer residues were observed in all groups, regardless of the endodontic sealer compositions. G1, G2 and G3 presented similar amount of sealer residues on dentinal surface after cleaning with 95% ethanol (p > 0.05). Conclusion: 95% ethanol was inefficiency to remove completely AH Plus, Epiphany SE and Sealapex residues of sealer-contaminated dentin.

Effect of Er:YAG laser and diamond drill on hybrid layer morphology obtained with self-etch adhesive: analysis by SEM and confocal laser scanning microscopy (CLSM)

This study aimed to evaluate the effect of Er:YAG (L) and diamond drills (DD) on: 1) the microshear bond strength (MPa); 2) the adhesive interface of two-step (TS) – Adper Scotchbond Multipurpose and one-step (OS) adhesives – Adper EasyOne, both from 3M ESPE. Material and methods: According to the preparation condition and adhesives, the samples were divided into four groups: DD_TS (control); DD_OS; L_TS and L_OS. 60 bovine incisors were randomly divided into experimental and groups: 40 for microshear bond strength (n = 10) and 20 for the adhesive interface morphology [6 to measure the thickness of the hybrid layer (HL) and length of tags (t) by CLSM (n = 3); 12 to the adhesive interface morphology by SEM (n = 3) and 2 to illustrate the effect of the instruments on dentine by SEM (n = 1)]. To conduct the microshear bond strength test, four cylinders (0.7 mm in diameter and 1 mm in height with area of adhesion of 0.38 mm) were constructed with resin composite (Filtek Z350 XT – 3M ESPE) on each dentin surface treated by either L or DD and after adhesives application. Microshear bond strength was performed in universal testing machine (EMIC 2000) with load cell of 500 kgf and a crosshead speed of 0.5 mm / min. Adhesive interface was characterized by thickness of hybrid layer (HL) and length of tags (t) in nm, with the aid of UTHSCSA ImageTool software. Results: Microshear bond strength values were: L_TS 34.10 ± 19.07, DD_TS 24.26 ± 9.35, L_OS 33.18 ± 12.46, DD_OS 21.24 ± 13.96. Two-way ANOVA resulted in statistically significant differences only for instruments (p = 0.047). Mann-Whitney identified the instruments which determined significant differences for HL thickness and tag length (t). Concerning to the adhesive types, these differences were only observed for (t). Conclusion: It can be concluded that 1) laser Er:YAG results in higher microshear bond strength values regardless of the adhesive system (TS and OS); 2) the tags did not significant affect the microshear bond strength; 3) the adhesive interface was affected by both the instruments for cavity preparation and the type of adhesive system used.

Ethanol is inneficient to remove endodontic sealer residues of dentinal surface

Introduction: Endodontic sealer residues on dentinal surface have negative effects on adhesion of adhesives system and/or can cause discoloration of the dental crown. Objective: To evaluate the efficacy of 95% ethanol in removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface. Material and methods: Thirty-two bovine incisor dental crown fragments (0.5 mm x 0.5 mm) were treated with 17% EDTA and 2.5% NaOCl. The specimens were divided into three experimental groups (n = 10): G1 (AH Plus), G2 (Epiphany SE) and G3 (Sealapex). In each group was applied a coating of one endodontic sealer type and were left undisturbed for 5 minutes. After this period, the specimens were cleaned with 95% ethanol. The control group was composed by two specimens that did not receive any sealer or cleaning treatment. The sealer residues persistence after cleaning with 95% ethanol was evaluated by scanning electron microscopy (x500) and a score system was applied. Data obtained were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Results: Moderate amount of endodontic sealer residues were observed in all groups, regardless of the endodontic sealer compositions. G1, G2 and G3 presented similar amount of sealer residues on dentinal surface after cleaning with 95% ethanol (p > 0.05). Conclusion: 95% ethanol was inefficiency to remove completely AH Plus, Epiphany SE and Sealapex residues of sealercontaminated dentin.

Clinical protocol for esthetic restoration using a self-etching adhesive

The advent of new adhesive systems is making techniques and clinical protocols to become faster and simpler, however it does not reduce the importance of knowledge of the properties, characteristics and interaction of dental materials with the tooth structure. Among the adhesives that have recently emerged, highlight the self-etching systems, especially the two-step selfetching, in which the acid primer is available in a separate bottle from the adhesive. These adhesives have shown good results for bond strength, microleakage and postoperative sensitivity, being an option for direct adhesive restorations in anterior teeth. This way, the present case report describes the step-by-step making of a class IV restoration in an upper right central incisor using atwo-step adhesive system, obtaining satisfactory results.

Influencia del número de capas de adhesivo en la conductancia hidraúlica en dentina humana

The aim of this study was to compare the hydraulic conductance in human dentin disks, where 1, 2 or 3 layers of adhesive Single Bond 2(SB2) and Single Bond Universal(SBU) were applied. 84 1 mm. thick(+/- 0.1 mm.) dentin disks were fabricated. Samples were divided into 7 groups (n = 12) Control (without adhesive), A1: one layer of SB2, A2: two layers SB2, A3: three layers SB2, B1: one layer SBU, B2: two layers of SBU, B3: three layers of SBU. The results as averages for the hydraulic conductance of each separate group were: Control (0.0363), A1 (0.0206), A2 (0.0070), A3 (0.0061), B1 (0.0161), B2 (0.0062), B3(0.0056) expressed µl/min.cm2. There is statistically significant difference CH, between the control group and those samples that one coat was applied (p = 0.000) and also between the application of one and two layers (p = 0.000). No difference between the two adhesives (p = 0.434). Summary Key words: Dentin, conductance, difussion adhesive layers.

Bond strenght of dental adhesive systems irradiated with ionizing irradiation

The aim of the present paper was to determine the effect of different types of ionizing radiation on the bond strength of three different dentin adhesive systems. Materials and Methods: One hundred twenty specimens of 60 human teeth (protocol number: 032/2007) sectioned mesiodistally were divided into 3 groups according to the adhesives systems used: SB (Adper Single Bond Plus), CB (Clearfil SE Bond) and AP (Adper Prompt Self-Etch). The adhesives were applied on dentin and photo-activated using LED (Lec 1000, MMoptics, 1000 mW/cm2). Customized elastomer molds (0.5 mm thickness) with three orifices of 1.2 mm diameter were placed onto the bonding areas and filled with composite resin (Filtek Z-250), which was photoactivated for 20 s. Each group was subdivided into 4 subgroups for application of the different types of ionizing radiation: ultraviolet radiation (UV), diagnostic x-ray radiation (DX), therapeutic x-ray radiation (TX) and without irradiation (control group, CG). Microshear tests were carried out (Instron, model 4411), and afterwards the modes of failure were evaluated by optical and scanning electron microscope and classified using 5 scores: adhesive failure, mixed failures with 3 significance levels, and cohesive failure. The results of the shear bond strength test were submitted to ANOVA with Tukey's test and Dunnett's test, and the data from the failure pattern evaluation were analyzed with the Mann Whitney test (p = 0.05). Results: No change in bond strength of CB and AP was observed after application of the different radiation types, only SB showed increase in bond strength after UV (p = 0.0267) irradiation. The UV also changed the failure patterns of SB (p = 0.0001). Conclusion: The radio-induced changes did not cause degradation of the restorations, which means that they can be exposed to these types of ionizing radiation without weakening the bond strength.

Effect of a Denture Adhesive on the Satisfaction and Kinesiographic Parameters of Complete Denture Wearers: A Cross-Over Randomized Clinical Trial

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação do uso de Selante de Fibrina derivado do veneno de serpente como arcabouço biológico de células tronco mesenquimais na regeneração óssea do fêmur de ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Descontaminação do resíduo industrial de couro, uma proposta para o desenvolvimento sustentável nos curtumes

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Influência da dentina bovina e do dispositivo de microtração na resistência de união de sistemas adesivos

Pós-graduação em Odontologia Restauradora - ICT

Fixação do enxerto ósseo autógeno em bloco com adesivos a base de cianoacrilato ou parafuso de titânio: estudo histológico em coelhos

Pós-graduação em Odontologia - FOA