Influence of the incorporation of titanium dioxide nanofibers net on bond strength and morphology of a total etching adhesive system.

Background: The aim of this study was to evaluate the nanoleakage and microtensile bond strength (µTBS) of an ethanol based-adhesive containing Titanium dioxide (TiO2) nanofibers to dentin. Material and Methods: TiO2 nanofiber was produced by electrospinning and it was inserted in an ethanol-based adhesive in 0.5, 1.5 and 2.5% by weight. The original adhesive did not receive nanofiber. The middle dentin was exposed by diamond saw under water-cooling and dentin was polished with wet 600-grit SiC abrasive paper. Resin composite build-ups were applied incrementally to the dentin after adhesive application. After storage in distilled water (24 hours/37°C) the teeth were sectioned perpendicularly to the bonded interface and sticks were obtained. Twenty-five sticks per group were tested by µTBS with a crosshead speed of 0.5mm/minute. The average values (MPa) obtained in each substrate were subjected to one-way ANOVA (α=0,05) with the tooth being considered the experimental unit. The nanoleakage pattern was observed in ten sticks per group and analyzed by Chi-square test (α=0,05). Results: There was no difference in µTBS among the experimental groups. However, there was a statistically significant difference among 2.5 % nanofiber adhesive, 0.5 % nanofibers and control groups, (p=0,028) in relation to nanoleakage. Conclusions: TiO2 nanofibers in 2.5% of weight inserted in dental adhesive reduced the nanoleakage, but did not improve the µTBS to dentin. Key words:Dentin-bonding agents, nanoleakage, tensile bond strength.

Reuse of healing abutments: Ethical, biological and professional training implications.

Background: The aim was to estimate the prevalence of reuse of healing abutments, the methods used in disinfection and to analyze the reasons that lead to the reuse of these components by professionals who work in rehabilitation with dental implants. Material and Methods: For this, an online data collection was carried out through a questionnaire developed in Google Forms. This questionnaire was applied to 284 specialists in implantology, randomized, of the 1,147 registered in the Regional Council of Dentistry of Rio Grande do Sul. The questionnaire was divided into three parts: the first containing the Free and Informed Consent Form; the second referring to the correspondents' demographic data; and the third part with information on reuse, disinfection and sterilization routines used, risk perception and information from manufacturers. To estimate the prevalence in the reuse of healing abutments by implantologists, the frequency of responses was used. Results: The results showed that almost all implantologists reuse healing abutments (98.1%). The main reasons for reuse were cost (71.2%) and practicality (26%). Regarding the limitations, 53.3% do not see limitations in its reuse, 20% associate it with increased roughness, 17.8% with the accumulation of organic matter and 8.9% with cross-infection as limitations for reuse. Already 95.3% did not receive any guidance from manufacturers on the reuse of these components. Enzymatic detergent and ultrasonic bath was the most used cleaning method (50.7%) followed by ultrasonic bath (23.3%). Autoclave was the method used for sterilization for all respondents. Conclusions: The reuse of healing abutments is a practice adopted by implantologists in the state of Rio Grande do Sul, Brazil and most professionals do not observe limitations in this practice since these components are used repeatedly. Decontamination with enzymatic detergent and an ultrasonic bath is the most commonly used procedure associated with autoclave sterilization. Key words:Abutment, reuse, decontamination, sterilization.

Cytotoxicity assessment of Bio-C Repair Íon+: A new calcium silicate-based cement.

Background. Direct pulp capping is a method designed to preserve the exposed dental pulp. Due to good biological, physical, and mechanical properties, new versions of calcium silicate-based materials have been developed as pulp capping materials. The present study aimed to evaluate the cytotoxic effects of four calcium silicate-based pulp capping materials, of which the Bio-C Repair Íon+ is still in an experimental phase. Methods. Biodentine, MTA Repair HP, Bio-C Repair, and Bio-C Repair Íon+ cements were dispensed in a metallic matrix to produce 125-mm3 specimens, which were immersed in Dulbecco's Modified Eagle Medium (DMEM) to obtain extracts. NIH 3T3 cells were cultured and exposed to the extracts for 24 hours and seven days. Cell viability was assessed by the methyl tetrazolium test (MTT). The mean values for the experimental and control groups (without treatment) were compared by analysis of variance (ANOVA) and post hoc Tukey tests, considering a significance level of 5%. Results. All the tested materials demonstrated a reduction in cell viability (P < 0.05). According to ISO 10993-5: 2009 (E), Bio-C Repair Íon+ exhibited mild and moderate cytotoxicity in the 24- hour and 7-day analyses, respectively. Bio-C Repair and Biodentine showed mild cytotoxicity, and MTA Repair HP exhibited moderate cytotoxicity at both intervals. Conclusion. The highest cell viability was demonstrated by Biodentine, MTA, and Repair HP, in descending order. Bio-C Repair and Bio-C Repair Íon+ showed moderate cytotoxicity, similar to MTA Repair HP in the 7-day analysis.

UV-Mediated Photofunctionalization of Indirect Restorative Materials Enhances Bonding to a Resin-Based Luting Agent.

PURPOSE: The potential of UV-mediated photofunctionalization to enhance the resin-based luting agent bonding performance to aged materials was investigated. METHODS: Sixty samples of each material were prepared. Yttria-stabilized zirconia (YZr) and Pd-Au alloy (Pd-Au) plates were fabricated and sandblasted. Lithium disilicate glass-ceramic (LDS) was CAD-CAM prepared and ground with #800 SiC paper. Half of the specimens were immersed in machine oil for 24 h to simulate the carbon adsorption. Then, all of the specimens (noncarbon- and carbon-adsorbed) were submitted to UV-mediated photofunctionalization with a 15 W UV-LED (265 nm, 300 mA, 7692 µW/cm2) for 0 (control groups), 5, and 15 min and subjected to contact angle (Ɵ) measurement and bonded using a resin cement (Panavia™ V5, Kuraray Noritake, Japan). The tensile bond strength (TBS) test was performed after 24 h. The Ɵ (°) and TBS (MPa) data were statistically analyzed using two-way ANOVA and Bonferroni correction tests (α = 0.05). RESULTS: In the carbon-adsorbed groups, UV-mediated photofunctionalization for 5 min significantly decreased Ɵ of all materials and increased TBS of YZr, and UV for 15 min significantly increased the TBS of LDS and Pd-Au. In noncarbon-adsorbed groups, UV-photofunctionalization did not significantly change the Ɵ or TBS except YZr specimens UV-photofunctionalized for 15 min. CONCLUSION: UV-mediated photofunctionalization might have removed the adsorbed hydrocarbon molecules from the materials' surfaces and enhanced bond strengths of Panavia™ V5 to YZr, LDS, and Pd-Au. Additionally, UV-mediated photofunctionalization improved the overall TBS of YZr. Further investigation on the optimum conditions of UV photofunctionalization on indirect restorative materials should be conducted.

Effect of heat treatment on cytotoxicity and polymerization of universal adhesives.

To assess, in vitro, the influence of heat air treatment on cytotoxicity and degree of conversion (DC) of universal self-etch adhesives (Ambar Universal APS, Scotchbond Universal Adhesive, and Tetric N-Bond Universal) in an NIH/3T3 fibroblast cell culture. Samples were divided into three groups: 1) no heat treatment (control), 2) 37°C and 3) 60°C heat treatment before photopolymerization. Cytotoxicity was analyzed by MTT assay and the DC by FTIR. All adhesives heated at 60°C showed reduced cytotoxicity levels when compared with those heated at 37°C. In general, DC of Ambar Universal APS presented the highest DC than Scotchbond Universal Adhesive and Tetric N-Bond Universal, and the hot air treatment do not influence the conversion. Heat treatment at 60°C was able to reduce the cytotoxicity of universal self-etch adhesives, even, the heat treatment does not enhances the DC.

Hot air stream reduces cytotoxicity of light-cured calcium hydroxide based cements.

BACKGROUND: The light-cured calcium hydroxide based cements have incomplete polymerization and unconverted monomers can cause pulp cell damage. The aim of this study was to evaluate the influence of a warm and hot air stream on the cytotoxicity of light-cured calcium hydroxide based cements. MATERIAL AND METHODS: The materials Dycal (conventional cement), Biocal, Hidrox-Cal, and Ultra-Blend Plus (light-cured calcium hydroxide cements) were submitted to cytotoxicity analysis after polymerization, without vs. with previous heat treatment with a warm (37°C) and a hot (60°C) air stream. Following polymerization, cements were maintained in culture medium for 24 hours and 7 days, and subjected to the MTT test. Data were analyzed using analysis of variance (ANOVA) followed by post-hoc Student-Newman-Keuls (<0.05). RESULTS: The results indicated significant differences between the materials according to their composition, i.e., light-cured cements treated with a jet of warm air showed similar cytotoxicity levels to those observed for conventional cement, suggesting that they may be considered alternatives in cases requiring pulp-capping treatment. CONCLUSIONS: Application of a hot air stream reduced cytotoxicity of materials tested. Key words:Dental pulp capping, dental cements, calcium hydroxide, cell survival.

Incorporation of a hydrophilic amide monomer into a one-step self-etch adhesive to increase dentin bond strength: Effect of application time.

The purpose was to evaluate the effect of a hydrophilic amide monomer on µTBS of one-step adhesive to dentin at different application times. Clearfil Universal Bond Quick (UBQ), experimental adhesive (UBQexp; same compositions as UBQ but hydrophilic amide monomer was replaced with 2-hydroxyethyl methacrylate), Clearfil SE ONE and Clearfil SE Bond were applied to midcoronal dentin prepared with 600-grit SiC at different application time (0, 10, 20 and 40 s). Water sorption (Wsp) and the ultimate tensile strength (UTS) of polymerized adhesives were also measured. UBQ showed significantly lower Wsp and higher UTS than UBQexp. At each application time, UBQ exhibited significantly higher µTBSs than UBQexp. UBQ showed the highest µTBS at 0 s application time among all the adhesives. When the application time was prolonged from 0 s to 10 s, only UBQ showed no significant difference. The hydrophilic amide monomer increased µTBS with reduction in Wsp and increase in the UTS and may allow a shortened application time.

Ultra-high-speed videography of resin-dentin interface failure dynamics under tensile load.

OBJECTIVES: Ultra-high-speed (UHS) videography was used to visualize the fracture phenomena at the resin-dentin interface during micro-tensile bond strength (µTBS) test. We also investigated whether UHS videography is applicable for failure-mode analysis. METHODS: Ten human mid-coronal dentin surfaces were bonded using Clearfil SE Bond either in self-etching (SE) or etch-and-rinse (ER) mode. After 24-h water storage, the samples were cut into beams for µTBS test and tested at a cross-head speed of 1 mm/min. The fracture phenomena at the bonded interface were captured using a complementary metal-oxide-semiconductor digital UHS camera at 299,166 frames per second. The failure modes were classified using UHS videography, followed by scanning electron microscopy (SEM) analysis. The failure-mode distributions determined by UHS videography and SEM analysis were statistically analyzed using Fisher's exact test with Bonferroni correction. RESULTS: The crack-propagation speed exceeded 1,500 km/h. No significant difference was found between the SEM and UHS videography failure-mode distributions in the SE mode. A significant difference appeared between them in the ER mode. Significant differences in the incidence of cohesive failures within the adhesive and at the adhesive-composite interface between the SE and ER modes were identified by both SEM and UHS videography. SIGNIFICANCE: UHS videography enabled visualization of the fracture dynamics at the resin- dentin interfaces under tensile load. However, the resolution at such high frame rate was insufficient to classify the failure mode as precisely as that of SEM. Nevertheless, UHS videography can provide more detailed information about the fracture origin and propagation.

O papel das mídias sociais na construção do conhecimento em Odontologia / The role of social media in the construction of knowledge in Dentistry

Este artigo, de cunho teórico, discute a construção do conhecimento em Odontologia no contexto da Sociedade em Rede, aproximando essa temática ao ponto de vista de alguns autores das Ciências Sociais Contemporâneas em voga. A bibliografia especializada aponta que a sociedade vive em uma constante transformação. Prova disso é que a construção de conhecimento pedagógico em Odontologia se dá hoje com maior intensidade na internet, principalmente nas mídias sociais, do que através da busca em livros. Por essa nova forma de agregar conhecimento ser uma realidade, é de fundamental importância que pessoas qualificadas sejam vetores de transmissão desses conhecimentos, de uma forma didática e com embasamento científico. Além disso, cabe aos professores se adaptarem ao novo estilo de construção do conhecimento pedagógico, elaborando aulas mais interativas e com o auxílio de ferramentas que chamem a atenção dos seus alunos e, concomitante a isso, ofereçam-lhes informações de qualidade.

This theoretical article discusses the construction of knowledge in dentistry in the context of the Network Society, bringing this theme closer to the point of view of some contemporary Social Science writers, nowadays in vogue. The specialized bibliography indicates that the society lives in a constant transformation, proof of this is that the construction of pedagogical knowledge in dentistry occurs today with greater intensity in the internet, mainly in the social media, than through the search in books. Because this new form of knowledge aggregation is a reality, it is of fundamental importance that qualified people are vectors of transmission of this knowledge, in a didactic and scientific basis. In addition, it is up to teachers to adapt to the new style of construction of pedagogical knowledge, developing more interactive classes and with the help of tools that attract the attention of their students and, at the same time, offer them quality information.

Effect of heat treatment on cytotoxicity of self-adhesive resin cements: Cell viability analysis.

OBJECTIVE: The aim of the study was to assess, in vitro, the influence on cytotoxicity of heat treatment applied before photopolymerization, while mixing three self-adhesive resin cements, in an NIH/3T3 fibroblast cell culture, based on cell viability measures. METHODS: Samples were divided into three groups: (1) no heat treatment while mixing (control), (2) 37°C, and (3) 60°C heat treatment while mixing. Cements were light-cured immediately after mixing and immersed in Dulbecco's Modified Eagle Media for the extraction of possibly uncured products after 24 h and 7 days. Cultures contained 0.5 mL of NIH/3T3 fibroblasts per well at a concentration of 0.4 × 105 cells/mL and specific extracts for each sample. STATISTICAL ANALYSIS USED: Data were statistically analyzed with ANOVA and post hoc Student-Newman-Keuls (significance of 5%). RESULTS: Cement cytotoxicity increased with time, as shown by the higher values observed at 7 days. There was a slight difference in intragroup cytotoxicity levels between 24 h and 7 days. Heat treatment at 60°C was associated with a major decrease in cytotoxicity levels in all three groups, both at 24 h and at 7 days, with no differences among the cements. CONCLUSIONS: Heat treatment at 60°C should be considered as a strategy to reduce cytotoxicity of self-adhesive resin cements, as evidenced by the results observed at 24 h and 7 days of analysis.

A successful approach to conrol burning mouth syndrome using matricaria recutita and cognitive therapy.

The burning mouth syndrome (BMS) has no specific clinical and laboratory signs. Its etiology is yet to be elucidated, but it is considered to be affected by multifactorial, psychological, and local and systemic factors. This condition is considered of great morbidity, and the main complaint of patients maybe associated with xerostomia, thirst, and altered taste. The present study aims to report two cases of BMS and to evaluate the outcome of cognitive therapy (CT) plus phytotherapy in the control of BMS. The patients were female, Caucasian, and aged between 58 and 69 years. The most BMS-affected anatomical parts were the lips and the tongue. In the clinical approach, oral and systemic evaluation, and disease management with CT plus chamomile tea were done. The patients were reassured, and their response to therapy one year after was found to be excellent despite few exacerbations in periods of great emotional stress. Thus, we conclude that psychological treatment is vital in the management of BMS, as CT, along with Matricaria recutita phytotherapy, displayed excellent results in the control of BMS. Key words:Anxiety, chamomile tea, xerostomia, psychosomatic.

Efeito da Temperatura de Evaporação do Solvente na Longevidade da Adesão de Adesivos Autocondicionantes à Dentina / Effect of Solvent Evaporation Temperature on Bonding Longevity of All-In-One Adhesives to Dentin

Avaliou-se a durabilidade da adesão de adesivos autocondicionantes à dentina após evaporação dos solventes com jato de ar frio e quente. Os sistemas adesivos Clearfil 3S Bond e OptiBond All-In-One foram aplicados em superfícies planas de dentina, a evaporação dos solventes feita com ar quente (60±2 o C) ou ar frio (20±2 o C), seguindo-se fotoativação (600mW/cm2 por 10 s) e restauração com compósito (3 x 2 mm). Após armazenagem em água destilada (24 horas / 37 o C), as amostras foram seccionadas para obtenção de paralelogramos de 0,8 mm2 para testar em tração (0,5mm/min) em 24 horas e 6 meses. Dois paralelogramos de cada grupo experimental foram preparados para observar a nanoinfiltração na interface com a dentina. Os valores médios da resistência adesiva (em MPa) de cada grupo foram tratados por Análise de Variância de três fatores e teste de Tukey (5%), sendo o dente a unidade experimental. Foi observada maior adesão após evaporação dos solventes com ar quente (p=0.000) no tempo de 24 horas de armazenagem (0.003). Não houve diferenças para o tipo de adesivo (p=0.343) e nem para a interação adesivo X tempo X temperatura de evaporação do solvente (p>0,05). Concluiu-se que a durabilidade da adesão foi influenciada pela temperatura de evaporação do jato de ar

To evaluate the bonding longevity of one-step self-etch adhesive systems to dentin, after solvent evaporation with warm or cold airstream. Clearfil 3S Bond and OptiBond All-In-One adhesives were applied on flat dentin surfaces, solvent evaporation was performed with a warm (60±2 o C) or cold air (20±2 o C), the surfaces were light cured (600mW/cm2 during 10 s), and blocks of compositeres min were built (3 x 2mm). After storage in distilled water (24-hour at 37 o C), the samples were sectioned into 0.8 mm2 sticks and tested in tensile (0.5 mm/min) at 24-hour and 6-month periods. Two sticks from each experimental group were prepared for nanoleakage observation of the bond interface. The mean bond strength values of experimental groups (in MPa) were subjected to a three- way Analysis of Variance and post-hoc Tukey´s test (5%), using tooth as the experimental unit. Higher bond strength was observed with warm air (p=0.000) for solvent evaporation, and 24 hour of water storage (0.003. No significant differences were observed for both the adhesive systems (p=0.343) and interactions.The bonding durability was influenced by the air temperature for solvent evaporation

Influence of different dentin drying methods on adhesive behavior of composite restorations

Aim: The aim of this study was to evaluate, in vitro, the influence of four different dentin drying methods (air drying for 10s, absorbent paper, endodontic suction cannula and air drying for 10s with subsequent re-wetting with distilled water), after etching with phosphoric acid gel 37%, on bond strength and microleakage of composite restorations. Material and Methods: Twenty sound bovine incisors were selected and sectioned transversely. The buccal surfaces were frayed until exposure of dentin, etched and washed with distilled water. Each specimen was subjected to one of the four different drying methods. A 3-step total-etch adhesive system (Adper Scotchbond™ Multi-Purpose) was used on 10 teeth and on the other 10, a 2-step total-etch adhesive system (Adper Single BondT™ 2) was used. Composite resin restorations in cylindrical shapes were made and, after thermocycling, the teeth were subjected to the microshear bond strength test. Cervical areas of the teeth were prepared and restored with the same techniques describe above. Cervical restorations were cut and subjected to microleakage analysis in the cervical margin. Data obtained were tabulated and statistically analyzed, using ANOVA, Chi-square and Kruskal-Wallis tests, and the significance level was set at 5%. Results: The results showed no statistically significant differences among the groups tested. Conclusions: It was concluded that all drying methods tested represent feasible alternatives to clinical application for total etch dentin-bonding agents.

Influence of filling technique and bevel preparation on marginal sealing of conventional and low shrinkage composite restorations

AIM: The aim of this study was to evaluate two composite restorations (conventional methacrylate-based and low shrinkage-based silorane), associated or not to beveling and incremental technique, in relation to the microleakage and marginal gap formation tests. MATERIAL AND METHODS: 30 sound human molars had their mesial and distal surfaces prepared with and without bevel. The teeth were divided into six groups according to the type of resin (conventional nanofilled or silorane resin), and restorative filling technique (incremental technique or builk). Microleakage and marginal gap formation data were statistically analyzed by Kruskal-Wallis and Chi-Square tests, with a significance level set at 5%. RESULTS: Group 1 (Z350 XT, without bevel, incremental technique) presented highest rate of microleakage and marginal gap in most of the restorations, with statistically significant differences. Groups 4 and 6 (P90, beveled, builk and P90, beveled and incremental technique) had lower rates of microleakage and absence of marginal gaps in most of the restorations. CONCLUSION: It's concluded that the silorane showed lower rates of marginal gaps and microleakage, when compared to the conventional methacrylate-based resin. Bevel preparation was effective in reducing microleakage and marginal gaps for both resins used. Incremental technique was not necessary when associated with low shrinkage composite resin.

The influence of air temperature for solvent evaporation on bonding of self-etch adhesives to dentin.

OBJECTIVE: This study evaluated the effect of air temperature (warm or cold) for solvent evaporation on bonding and nanoleakage of self-etching adhesives to dentin. MATERIALS AND METHODS: The adhesives Clearfil 3S Bond [S3], OptiBond All-In-One [OB], Adper SE Plus [AD], and Silorane adhesive [SI] were applied on dentin surfaces, and a warm (60 ± 2°C) or cold air (20 ± 1°C) was applied and light-cured. After water storage (24 h), the teeth were sectioned into sticks (0.8 mm(2)) and tested in tensile. Then, they were immersed in a 50% solution of silver nitrate, photo-developed and the nanoleakage observed in a scanning electron microscope. The bond strength and nanoleakage pattern were analyzed by two-way analysis of variance and post hoc Tukey's test (α =0.05). RESULTS: Higher bond strength and lower silver nitrate uptake were observed for the adhesives under warm condition (P < 0.05). AD and SI showed better adhesive results than S3 and OB (P < 0.05). CONCLUSION: The use of a warm air was useful to improve the bonding and diminish the nanoleakage of adhesive systems to dentin.

Atendimento de urgência frente ao traumatismo alvéolo dentário: relato de caso clínico / Urgent care outside the tooth injuries: case report

Os traumatismos dentários são situações de urgência odontológica que impõem ao profissional um atendimento rápido, porém minucioso. Apesar da agilidade no primeiro atendimento, na maioria das vezes é necessário o acompanhamento do paciente por um longo período. O objetivo deste trabalho é relatar o caso de um menino que compareceu ao atendimento de urgência da Clínica Infantil da Universidade Luterana do Brasil (Ulbra) - campus Cachoeira do Sul/RS - Brasil, com várias lesões decorrentes de uma queda de bicicleta. O paciente chegou 24 horas após o trauma com vária lacerações faciais que já haviam sido suturadas no hospital anteriormente. Os dentes envolvidos, o 11, 12, 13,21,22 e 23, apresentavam lesões de fratura coronária, subluxação e luxação extrusiva Realizou-se uma radiografia da região e não se detectou fratura radicular ou da tábua óssea vestibular. No primeiro atendimento, optou-se pela confecção de uma contenção semirrígida manto por três semanas, pois alguns dentes estavam com grande mobilidade. Desde o atendimento de urgência o paciente vem sendo acompanhado e tratado na Universidade. Podemos concluir que o tratamento de urgência é bastante complexo, uma boa anamnese, um bom exame clínico e exames complementares são indispensáveis na instituição de um plano de tratamento rápido e adequada. O prognóstico é muitas vezes duvidoso, podendo envolver várias especialidades odontológicas e se torna mais favorável quando o profissional tem conhecimento, agilidade no tratamento de urgência e faz o encaminhamento correto do paciente quando necessário.

Dental injuries are emergencies that require the dental professional a fast, but thorough. Despite the agility in primary care, most often it is necessary to monitor the patient for a long perio The objective of this study is to report the case of a boy who attended the emergency care of theChildren's Clinic Lutheran University of Brazil (Ulbra) - campus Cachoeira do Sul/RS - Brazil, with multiple injuries resulting from a fali from a bike. The patient arrived 24 hours after the trauma with multiple facial lacerations that had been sutured to the hospital previously. The teeth involved, 11, 12, 13,21,22 and 23, had lesions of coronary fracture, extrusive luxation and subluxation. Was held radiography of the region was not detected root fracture or buccal bone plate. In the firs visit, it was decided for the construction of a semi-rigid containment maintained for three weeksi because some teeth were highly mobile. From the urgent care the patient has been followed an treated at the University. We can conclude that emergency treatment is quite complex, a good clinical history, a good clinical examination and exams are essential in establishing a plan for prompt and appropriate treatment. The prognosis is often uncertain, may involve various dental specialti and becomes more favorable when the professional's knowledge, speed in emergency treatmen and makes the correct routing of the patient when needed.

Six-month evaluation of a resin/dentin interface created by methacrylate and silorane-based materials.

OBJECTIVES: This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. MATERIAL AND METHODS: The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. RESULTS: Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). CONCLUSIONS: The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Six-month evaluation of a resin/dentin interface created by methacrylate and silorane-based materials

Objectives: This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods: The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results: Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions: The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-year follow-up.

OBJECTIVE: This randomized double-blind clinical trial compared the performance of posterior composite restorations with or without bevel, after 1-year follow-up. MATERIAL AND METHODS: Thirteen volunteers requiring at least two posterior composite restorations were selected. Twenty-nine cavities were performed, comprising 14 without bevel (butt joint) and 15 with bevel preparation of the enamel cavosurface angle. All cavities were restored with simplified adhesive system (Adper Single Bond) and composite resin (Filtek P60). A halogen light curing unit was used through the study. Restorations were polished immediately. Analysis was carried out at baseline, after 6 months and after 1 year by a calibrated evaluator (Kappa), according to the FDI criteria. Data were statistically analyzed by Mann-Whitney test (p <0.05). RESULTS: Beveled and non-beveled cavities performed similarly after 1 year follow-up, regarding to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster and anatomic form. However, for surface and marginal staining, beveled cavities showed significantly better performance (p<0.05) than butt joint restorations. CONCLUSIONS: It was concluded that the restorations were acceptable after 1 year, but restorations placed in cavities with marginal beveling showed less marginal staining than those placed in non-beveled cavities.

A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-year follow-up

OBJECTIVE: This randomized double-blind clinical trial compared the performance of posterior composite restorations with or without bevel, after 1-year follow-up. MATERIAL AND METHODS: Thirteen volunteers requiring at least two posterior composite restorations were selected. Twenty-nine cavities were performed, comprising 14 without bevel (butt joint) and 15 with bevel preparation of the enamel cavosurface angle. All cavities were restored with simplified adhesive system (Adper Single Bond) and composite resin (Filtek P60). A halogen light curing unit was used through the study. Restorations were polished immediately. Analysis was carried out at baseline, after 6 months and after 1 year by a calibrated evaluator (Kappa), according to the FDI criteria. Data were statistically analyzed by Mann-Whitney test (p <0.05). RESULTS: Beveled and non-beveled cavities performed similarly after 1 year follow-up, regarding to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster and anatomic form. However, for surface and marginal staining, beveled cavities showed significantly better performance (p<0.05) than butt joint restorations. CONCLUSIONS: It was concluded that the restorations were acceptable after 1 year, but restorations placed in cavities with marginal beveling showed less marginal staining than those placed in non-beveled cavities.