[Comparison of flow conditions of adhesives and retention force of restorations among four cement-retained methods of implant-supported fixed prostheses].

Objective: To compare the effect on the flow conditions of adhesives and the retention force of restorations among different cement-retained methods of implant-supported fixed prostheses. Methods: Four common cement-retained methods were selected, including the occlusal hole for screw access (OH), the lingual hole for adhesives overflow (LH), the resin replica for titanium abutment (RR), and the traditional cement-retained method (the control group). The adhesive used in this study was resin-modified glass ionomer cement. The two-dimensional analysis models of computational fluid dynamics (CFD) were established. The flow conditions of adhesives in the adhesion process was analyzed by the CFD analysis. The internal filling ratio and the amount of neck overflow of adhesives below the edge of the prosthesis were calculated. Ten zirconia prostheses in each group were processed and cemented. The retention force was examined by mechanical tensile experiments in vitro. Results: The CFD analysis showed the internal filling ratio of adhesives from high to low was the LH group, the OH group, the RR group and the control group. The amount of neck overflow of adhesives below the edge of the prosthesis from less to more was the RR group, the OH group, the LH group and the control group. The retention force was (240.7±33.9) N in the control group, (278.2±59.1) N in the OH group, (292.9±47.9) N in the LH group, and (262.8±59.4) N in the RR group. There was a statistically significant difference in the retention force between the LH group and the control group (P=0.029). There was no significant difference among the other groups (P>0.05). Conclusions: The modified cement-retained methods can effectively reduce the amount of neck overflow of adhesives, and improve the filling condition of adhesive in the adhesive clearance to ensure the retention force of the prostheses. Clinically, the appropriate modified cement-retained method should be selected according to the three-dimensional position of the implant and the position of prosthetic margin.

Influência do uso do silano na resistência de união e no padrão de fratura nos reparos da resina indireta Ceramage com a resina direta Filtek Z350 / Influence of silane on bond strength and fracture pattern for indirect resin Ceramage repair with direct resin Filtek Z350

Pouca informação encontra-se disponível sobre a influência dos diferentes tratamentos de superfície das restaurações de resina indireta na resistência de união com as resinas diretas usadas para reparo. O objetivo deste estudo foi avaliar a influência de diferentes técnicas com uso do silano no reparo da resina indireta Ceramage na resistência ao cisalhamento e no padrão de fratura com a resina composta direta Filtek Z350. Blocos de resina composta indireta Ceramage (SHOFU) foram confeccionados e envelhecidos por 3 semanas em água destilada à 37°C. Posteriormente, foram jateados com óxido de alumínio e distribuídos aleatoriamente em 4 grupos de 10. No grupo 1, a superfície da resina Ceramage recebeu o adesivo convencional Adper Single Bond 2 (3M ESPE). No grupo 2 foi aplicado adesivo universal Adper Single Bond Universal (3M ESPE). Nos grupos 3 e 4, foi feita a aplicação do silano Silano Mais (Dentsply Sirona) e dos adesivos convencional e universal respectivamente. Foram confeccionados cilindros de resina composta direta Filtek Z350 (3M ESPE) na superfície da resina indireta Ceramage em todos os espécimes. Em seguida foi feito o teste de cisalhamento na máquina de teste universal (EMIC) após o armazenamento dos espécimes em água destilada à 37°C por 24 horas. O estereomicroscópio foi utilizado para analisar as falhas. A análise estatística foi feita pelo teste estatístico de Kruskal-Wallis. Não houve uma diferença estatisticamente significativa (p>0,05) na resistência de união e no padrão de fratura entre as diferentes técnicas de aplicação do silano no tratamento de superfície. Concluiu-se que o uso do silano pode não ser imprescindível para aumentar a resistência de união do reparo da resina indireta Ceramage com a resina direta Filtek Z350. No entanto, clinicamente é provável que se tenha uma maior chance de sucesso no reparo com a aplicação do silano. (AU)

Just few information is available about the influence of different surface treatments of indirect resin restorations on bond strength to direct resins used for repair. The objective of this study was to evaluate the influence of different techniques with the use of silane on the shear bond strength and fracture pattern of indirect resin Ceramage to Filtek Z350 direct composite resin. Ceramage indirect composite blocks (SHOFU) were made and aged in distilled water at 37 ° C for 3 weeks. Subsequently, they were sandblasted with aluminum oxide and randomly divided into 4 groups of 10. In group 1, the surface of the Ceramage resin received the conventional adhesive Adper Single Bond 2 (3M ESPE). In group 2, Adper Universal Bond universal adhesive (3M ESPE) was applied. In groups 3 and 4, the Silano Mais silane (Dentsply Sirona) and the conventional and universal adhesives were applied respectively. Composite resins cylinder of Filtek Z350 (3M ESPE) were made on the surface of the indirect resin Ceramage in all specimens. The shear test was then performed on the universal test machine (EMIC) after their storage in destilled water at 37°C for 24 hours. The stereomicroscope was used to analyze the fractures. Statistical analysis was done by Kruskal-Wallis test. There were no statistically significant differences (p>0,05) in bond strength values and in fracture pattern between the different techniques of application of silane in surface treatment. It was concluded that the silane coupling agent would not be necessary for repairing indirect resin Ceramage with composte resin Filtek Z350. However, clinically it is likely to have a better chance of successful repair with silane application. (AU)

Formação de fendas em restaurações de resina composta: polimento imediato versus tardio / Gap formation in composite resin restorations: immediate versus late polishing

O objetivo deste estudo foi avaliar a influência do momento da etapa de polimento, imediato ou após sete dias, na formação de fendas em restaurações de resina composta. Cavidades cilíndricas foram preparadas nas superfícies vestibulares de incisivos bovinos. Cada cavidade foi hibridizada com um dos dois sistemas adesivos: convencional (Adper Single Bond 2) ou autocondicionante (Single Bond Universal), e restaurada usando uma das três resinas compostas: nanoparticulada (Z350), micro-híbrida (P60) e bulk-fill (ONE). As cavidades restauradas foram divididas em dois subgrupos de acordo com o tempo de polimento, imediato ou postergado por 7 dias após a restauração. Por meio da combinação dos sistemas adesivos, resinas compostas e tempos de polimento, foram criados 12 grupos (n = 5). As porcentagens de fendas marginais (%FM) foram avaliadas quantitativamente com o microscópio confocal de varredura a laser. O módulo de elasticidade das resinas compostas foi obtido por meio do teste de flexão em três pontos. Os dados foram analisados por análise de variância e pelo teste de Tukey's HDS (α = 0,05). Em relação ao sistema adesivo, a %FM foi estatisticamente maior para as cavidades restauradas com Single Bond Universal (p<0,05). Com relação às resinas compostas, o resultado foi o seguinte: P60 > ONE > Z350 (p<0,05). O tempo de polimento imediato apresentou %FM estatisticamente menor que o tardio (p<0,05). P60 apresentou o maior módulo de elasticidade (p<0,05). Foi possível concluir que o polimento imediato gera menor formação de fendas em restaurações de resina composta. (AU)

The aim of this study was to analyze the influence of the polishing time, immediately or after seven days, in gap formation in composite resin restorations. Cylindrical cavities were prepared on buccal surfaces of bovine incisors. Each cavity was hybridized with one of the two adhesive systems: etch-and-rinse (Adper Single Bond 2) and self-etching (Single Bond Universal), and restored using one of the three composite resins: nanofilled (Z350), minifilled hybrid (P60) and bulk-fill (ONE). The cavities restored were divided in two subgroups according to polishing time, immediately or delayed by 7 days after specimen restoration. Through the combination of the adhesive systems, composite resins and polishing times, 12 groups were created (n=5). Percentages of marginal gaps (%MG) were quantitatively assessed with confocal laser scanning microscope. The flexural modulus of the composite resins was obtained from bar-shaped specimens submitted to three-point bending test. The data were analyzed by three-way ANOVA and Tukey's HSD test (α=0.05). Regarding adhesive system, %MG was statistically higher for cavities restored with Single Bond Universal (p<0.05). With respect to composite resins, the result was as follow: P60 > One > Z350 (p<0.05). Immediate polishing time presented statistically lower %MG than delayed one (p<0.05). P60 presented the highest flexural modulus (p<0.05). It was possible to conclude that immediate polishing generates less gap formation in composite resin restorations. (AU)

[Correspondence between advances of dental composites and adhesives and clinical guidelines for direct restorations].

The longevity of direct adhesive restoration is related to the restorative materials, the patient and the professional. On one hand, dental composites/adhesives have been modified and developed to fulfill the criteria for clinical application. On the other hand, the clinical guidelines for adhesive restorations have been released and updated accordingly, which would prolong the longevity of restorations. In this commentary, the removal of carious tissues, interface preparation for bonding and application of adhesives are emphasized. The administrative measures for registration and clinical evaluation criteria for adhesive restorative material are also introduced.

OCT for early quality evaluation of tooth-composite bond in clinical trials.

OBJECTIVES: To evaluate early quality of composite restorations with a universal adhesive in different application modes clinically and with optical coherence tomography (OCT). METHODS: 22 patients with four non-carious cervical lesions each received composite restorations (Filtek Supreme™ XTE, 3 M). The universal adhesive Scotchbond Universal™(SBU, 3 M) was applied with three etching protocols: self-etch (SE), selective-enamel-etch (SEE) and etch-and-rinse (ER). The etch-and-rinse adhesive OptiBond™ FL (OFL, Kerr) served as a control. Restorations were imaged by OCT (Thorlabs) directly after application (t0). After 14 days (t1) and 6 month (t2) OCT imaging (interfacial adhesive defects) was repeated combined with clinical assessment (FDI criteria). Groups were compared by Friedman-/Wilcoxon- and McNemar-Test. RESULTS: No differences were seen clinically between groups (pi ≥ 0.500). OCT assessment revealed more adhesive defects at the enamel interface with SBU/SE at t0-t2 compared to all groups (pi ≤ 0.016). OFL showed more defects than SBU/ER (t1: p = 0.01; t2: p = 0.083). At dentin/cementum interface OFL exhibited more adhesive defects than SBU with all conditioning modes (t0, t1, pi ≤ 0.003) and at t2 to SBU/SE and SBU/ER (p < 0.001). Since t1 defects with SBU were detected more frequently in the SE and SEE modes compared to ER (pi ≤ 0.037). In contrast to SBU defects increased with OFL up to t2 (pi ≤ 0.007). CONCLUSIONS: In contrast to clinical evaluation, OCT revealed subtle adhesive defects directly after application that might interfere with clinical success. It was demonstrated that ER does not decrease initial adhesion of SBU to dentin.

Adhesives for bonded molar tubes during fixed brace treatment.

BACKGROUND: Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. The success of a fixed appliance depends partly on the metal attachments (brackets and bands) being glued to the teeth so that they do not become detached during treatment. Brackets (metal squares) are usually attached to teeth other than molars, where bands (metal rings that go round each tooth) are more commonly used. Orthodontic tubes (stainless steel tubes that allow wires to pass through them), are typically welded to bands but they may also be glued directly (bonded) to molars. Failure of brackets, bands and bonded molar tubes slows down the progress of treatment with a fixed appliance. It can also be costly in terms of clinical time, materials and time lost from education/work for the patient. This is an update of the Cochrane review first published in 2011. A new full search was conducted on 15 February 2017 but no new studies were identified. We have only updated the search methods section in this new version. The conclusions of this Cochrane review remain the same. OBJECTIVES: To evaluate the effectiveness of the adhesives used to attach bonded molar tubes, and the relative effectiveness of the adhesives used to attach bonded molar tubes versus adhesives used to attach bands, during fixed appliance treatment, in terms of: (1) how often the tubes (or bands) come off during treatment; and (2) whether they protect the bonded (or banded) teeth against decay. SEARCH METHODS: The following electronic databases were searched: Cochrane Oral Health's Trials Register (to 15 February 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 1) in the Cochrane Library (searched 15 February 2017), MEDLINE Ovid (1946 to 15 February 2017), and Embase Ovid (1980 to 15 February 2017). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised controlled trials of participants with full arch fixed orthodontic appliance(s) with molar tubes, bonded to first or second permanent molars. Trials which compared any type of adhesive used to bond molar tubes (stainless steel or titanium) with any other adhesive, were included.Trials were also included where:(1) a tube was bonded to a molar tooth on one side of an arch and a band cemented to the same tooth type on the opposite side of the same arch;(2) molar tubes had been allocated to one tooth type in one patient group and molar bands to the same tooth type in another patient group. DATA COLLECTION AND ANALYSIS: The selection of papers, decision about eligibility and data extraction were carried out independently and in duplicate without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. MAIN RESULTS: Two trials (n = 190), at low risk of bias, were included in the review and both presented data on first time failure at the tooth level. Pooling of the data showed a statistically significant difference in favour of molar bands, with a hazard ratio of 2.92 (95% confidence intervals (CI) 1.80 to 4.72). No statistically significant heterogeneity was shown between the two studies. Data on first time failure at the patient level were also available and showed statistically different difference in favour of molar bands (risk ratio 2.30; 95% CI 1.56 to 3.41) (risk of event for molar tubes = 57%; risk of event for molar bands 25%).One trial presented data on decalcification again showing a statistically significant difference in favour of molar bands. No other adverse events identified. AUTHORS' CONCLUSIONS: From the two well-designed and low risk of bias trials included in this review it was shown that the failure of molar tubes bonded with either a chemically-cured or light-cured adhesive was considerably higher than that of molar bands cemented with glass ionomer cement. One trial indicated that there was less decalcification with molar bands cemented with glass ionomer cement than with bonded molar tubes cemented with a light-cured adhesive. However, given there are limited data for this outcome, further evidence is required to draw more robust conclusions.

Development and testing of novel bisphenol A-free adhesives for lingual fixed retainer bonding.

AIM: To comparatively evaluate the properties of two BPA-free experimental adhesives (EXA, EXB) for lingual fixed retainer bonding versus a commercially available reference material (Transbond LR-TLR) based on BPA-compound. MATERIALS AND METHODS: The experimental materials were a flowable 60 per cent glass filler-filled UEDMA/TEGDMA flowable composite (EXB) and a 70 per cent glass filler-filled paste composite with PCDMA/UEDMA/TEGDMA co-monomers. The properties tested were degree of conversion (DC%), mechanical properties (Martens hardness-MH, elastic modulus-EIT, elastic index-nIT), effect of prolonged (6 months) water storage (changes in Vickers microhardness-VHN) and pull-out strength employing a multi-stranded wire. RESULTS: EXB showed the highest DC% (63.6 per cent), followed by EXA (50.5 per cent) and TRL (44.1 per cent), with all means differences being statistically significant (P < 0.05). The statistical rankings of MH (MPa) and EIT (GPa) means were TLR (76.1MPa; 17.3GPa) > EXA (53MPa; 12.9GPa) > EXB (12.9MPa; 6.7GPa), whereas for nIT, EXB (40 per cent) > EXA (34.9 per cent), TLR (33.6 per cent). All materials were affected by prolonged water storage with significant differences among them in VHN. TLR was the most affected material (ΔVHN = -11 per cent), followed by EXA (ΔVHN = -6.8 per cent) and EXB (ΔVHN = -4.2 per cent). No statistically significant differences were found in the pull-out strength testing (24-24.2 N range) and failure mode (70-77 per cent mixed). CONCLUSION: Considering the differences between the two experimental materials, it may be concluded that the material containing the PCDMA/UEDMA/TEGDMA co-monomers may be used as an alternative to the control.

Mechanical properties of contemporary orthodontic adhesives used for lingual fixed retention.

OBJECTIVE: The aim of the present study was to test the mechanical properties of different adhesives used in orthodontics for fixed retainers and to investigate their possible interrelations. MATERIALS AND METHODS: Specimens of six different adhesive resins were prepared: Transbond XT, Transbond LR and an experimental BPA-free orthodontic adhesive, as well as IPS Empress Direct (IPS-ED), ZNano and Accolade. The mechanical properties tested were Martens hardness (HM), indentation modulus (EIT), the ratio of elastic to total work, commonly known as elastic index (ηIT) and Vickers hardness (HV). These properties were determined using instrumented indentation testing according to ISO 14577-2002. The results of the aforementioned properties were statistically compared with one-way ANOVA-test and Student-Newman-Keuls multiple comparison test at a=0.05, while possible correlations among the properties tested were analyzed by Pearson correlation. RESULTS: Significant differences were identified among all the materials tested for HM, with Transbond LR presenting the highest value. This resin presented the highest EIT too. Significant EIT differences were identified among the materials and only ZNano and IPS-ED showed no significant differences for this property. Transbond LR and ZNano showed higher HV values. ZNano demonstrated the highest elastic index. Pearson analysis showed a strong positive correlation between HM and EIT (0.970), HM and HV (0.837), and EIT and HV (0.695), while a weak negative correlation was found between EIT and elastic index (-0.505). CONCLUSIONS: The materials tested demonstrated significant differences in their mechanical properties, and thus differences in their clinical performance are anticipated.

Efeitos de diferentes adesivos na colagem ortodôntica indireta: resistência ao cisalhamento, alteração de cor e rugosidade do esmalte / Effects of different adhesives on indirect orthodontic bonding: shear strength, color change and enamel roughness

O objetivo deste estudo foi avaliar in vitro quatro sistemas adesivos utilizados na colagem indireta ortodôntica, quanto à resistência ao cisalhamento e às alterações de cor que os tags de resina podem provocar no esmalte após a remoção dos braquetes, bem como dois métodos de remoção de resina quanto à rugosidade do esmalte. Foram utilizados 70 incisivos bovinos, distribuídos em 7 grupos (n=10): controle (sem colagem), colagem direta (DTBX Transbond XT) e colagem indireta (ITBX, IZ350, ISONDHI, ISEP, ITBXp). Nos grupos ITBX e ITBXp foi utilizado o adesivo Transbond XT, no IZ350 a resina flow Z350, no ISONDHI o adesivo Sondhi, e no grupo ISEP o adesivo SEP. Resistência ao cisalhamento, índice de remanescente do adesivo e rugosidade superficial do esmalte foram avaliados. Em todos os grupos, o remanescente resinoso foi removido com broca de tungstênio em baixa rotação, exceto no grupo ITBXp, no qual foi usado polidor de óxido de alumínio. Os dentes foram expostos ao manchamento com café e tiveram sua cor avaliada pelo sistema (CIE) LAB, neste momento e previamente à colagem. Os resultados mostraram que os grupos ISONDHI e ISEP apresentaram forças de adesão significantemente menores (p<0,01). DTBX obteve maior quantidade de dentes com todo o adesivo no esmalte (70%) em comparação com grupos da colagem indireta (0-­30%). A rugosidade foi analisada apenas em ITBX e ITBXp, e ambos os métodos de remoção do adesivo demonstraram o aumento na rugosidade. Dessa forma, pode-­se concluir que a colagem direta e indireta tem resultados similares e todos os adesivos utilizados possuem resistência de adesão satisfatórias. O uso de brocas e polidores aumentaram a rugosidade do esmalte, no entanto, os polidores garantiram melhor a integridade da rugosidade inicial. Os tags não são capazes de alterar a cor do dente (AU)

This study aimed at making an in vitro evaluation of four adhesive systems used in indirect orthodontic bonding, regarding the shear strength and color change caused by resin tags after debonding, and the enamel roughness observed after applying two enamel clean-­up techniques. Seventy bovine incisors were used, distributed in 7 groups: control (no bonding), direct bonding (DTBX) and indirect bonding (ITBX, IZ350, ISONDHI, ISEP, ITBXp). Transbond XT adhesive was used on the DTBX, ITBX and ITBXp groups, flow resin Z350 on IZ350, Sondhi adhesive on ISONDHI, and SEP adhesive on the ISEP group. Shear bond strength, the adhesive remnant index and enamel roughness were evaluated. The adhesive remnant was removed from all the groups with a low speed tungsten bur, except the ITBXp group, on which an aluminum oxide polisher was used. After coffee staining, the color was evaluated by CIE color parameters immediately after staining and prior to bonding. ISONDHI and ISEP groups showed significantly lower adhesion forces (p<0.01). DTBX had a greater number of teeth with all the adhesive on the enamel (70%), compared with the indirect bonding groups (0-­30%). The roughness analyzed in ITBX and ITBXp was found to be greater resulting from both clean-­up techniques used. It can be concluded that direct and indirect bonding have similar results and that all the adhesives used have satisfactory adhesion strength. Use of burs and polishers increases the enamel roughness, but polishers ensure greater integrity of the initial roughness. Resin tags do not change the color of the teeth (AU)

Análise da qualidade da obturação em raizes mesiais de molares inferiores utilizando dois cimentos endodônticos: EndoSequence e AH Plus / Analysis of the quality of obturation in mesial roots of molars using two endodontic cements: EndoSequence and AH Plus

Objetivo: O objetivo deste estudo foi avaliar, por microtomografia computadorizada (micro-CT), a qualidade da obturação de canais mesiais de molares inferiores utilizando os cimentos EndoSequence BC Sealer e AH Plus. Metodologia: Vinte molares inferiores foram divididos em dois grupos (n=10) de acordo com o cimento utilizado na obturação. O preparo quimico-mecânico foi realizado com as limas rotatórias K3XF. As amostras foram escaneadas por micro-CT antes e depois da intrumentação, e depois da obturação. O volume do sistema de canais radiculares (SCR) após a instrumentação e o volume da obturação foram calculados, assim, o volume percentual da obturação e dos espaços vazios pôde ser obtido. Resultados: Todas as amostras apresentaram volumes de obturação menores do que o volume pós instrumentação do SCR (p < 0,05). Não houve diferença estatística significante entre os grupos quanto ao volume da obturação e o volume de espaços vazios (p >0,05). Conclusões: Os cimentos endodônticos EndoSequence BC Sealer e AH Plus proporcionaram uma qualidade semelhante de obturação em canais mesiais de molares inferiores. Nenhum dos cimentos foi capaz de proporcionar total preenchimento do SCR. (AU)

Aim: The aim of this study was to evaluate, by computadorized microtomography (micro-CT), the root canal filling quality of mesial roots of mandibullar molars using EndoSequence BC Sealer and AH Plus sealers. Methodology: Twenty mandibular molars were divided into two groups (n=10) according to the sealer used in the obturation. Root canals were prepared using K3XF rotary files. The specimens were scanned before and after instrumentation, and after obturation by using micro-CT. The root canal system volume after instrumentation, and the filling volume were calculated, so the percentage volume of the filling, and voids and gaps could be obtained. Results: All the specimens presented the final volume smaller than the inicial volume (P < 0.05). There was no significant difference between groups with regard to the filling volume and voids and gaps volume (P > 0.05). Conclusions: EndoSequence BC Sealer and AH Plus sealer promoted a similar root filling quality in mesial root canals of madibullar molars. None of the sealers was able to fill the entire area of the root canal system. (AU)

In vitro analysis of shear bond strength and adhesive remnant index of different metal brackets

ABSTRACT Introduction: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. Objectives: To evaluate the bond strength and the adhesive remnant index (ARI) of different brands of metal brackets. Material and Methods: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM). Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. Results: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM) to 9.871 ± 5.106 MPa (TecnidentTM). The majority of the ARI index scores was 0 and 1. Conclusion: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface.

RESUMO Introdução: atualmente, há uma grande diversidade de braquetes ortodônticos no mercado brasileiro, e a avaliação desses é fundamental para que os profissionais conheçam suas propriedades e possam qualificar a sua escolha. Objetivo: avaliar o desempenho de diferentes braquetes metálicos - com diferentes características de base -, por meio da resistência de união e do Índice de Adesivo Remanescente (IAR). Material e Métodos: braquetes de sete marcas distintas foram testados (Morelli®, American Orthodontics®, TP Orthodontics®, Abzil-3M®, Orthometric®, Tecnident® e UNIDEN®). Os braquetes foram colados em incisivos bovinos totalizando 105 corpos de prova. O teste de resistência ao cisalhamento foi realizado 24h após a colagem e, em seguida, foi avaliado o IAR, por meio do uso de um microscópio óptico, em aumento de 10 vezes. Resultados: a média dos valores de resistência de união variou entre 3,845 ± 3,997 MPa (Morelli®) e 9,871 ± 5,106 MPa (Tecnident®). A maioria dos escores do IAR foi de 0 e 1. Conclusão: entre os braquetes avaliados, o que obteve a menor média de resistência de união foi o Morelli®. A avaliação geral dos grupos indicou maior número de falhas de colagem na interface esmalte/adesivo.

Adhesives for fixed orthodontic bands.

BACKGROUND: Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. OBJECTIVES: To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. SEARCH METHODS: The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. DATA COLLECTION AND ANALYSIS: All review authors were involved in study selection, validity assessment and data extraction without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. MAIN RESULTS: Five RCTs and three CCTs were identified as meeting the review's inclusion criteria. All the included trials were of split-mouth design. Four trials compared chemically cured zinc phosphate and chemically cured glass ionomer; three trials compared chemically cured glass ionomer cement with light cured compomer; one trial compared chemically cured glass ionomer with a chemically cured glass phosphonate. Data analysis was often inappropriate within the studies meeting the inclusion criteria. AUTHORS' CONCLUSIONS: There is insufficient high quality evidence with regard to the most effective adhesive for attaching orthodontic bands to molar teeth. Further RCTs are required.

In vitro analysis of shear bond strength and adhesive remnant index of different metal brackets.

INTRODUCTION:: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. OBJECTIVES:: To evaluate the bond strength and the adhesive remnant index (ARI) of different brands of metal brackets. MATERIAL AND METHODS:: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM). Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. RESULTS:: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM) to 9.871 ± 5.106 MPa (TecnidentTM). The majority of the ARI index scores was 0 and 1. CONCLUSION:: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface.

Avaliação da influência dos diferentes tempos e meios de armazenamento de sistemas autocondicionantes na adesão de bráquetes ortodônticos / Evaluation of the influence of different times and storage media of self-etching systems on the adhesion of orthodontic brackets

O objetivo dos autores deste trabalho foi avaliar o grau de adesão do sistema autocondicionante (TPSEP) quanto à variação do tempo e meios de armazenamento. Foram avaliados a resistência ao cisalhamento e o Índice de Remanescente Adesivo. 120 incisivos bovinos foram divididos em 12 grupos sendo 2 controles e 10 grupos de trabalho, foram avaliados os tempos e o tipo de armazenamento do TPSEP aberto. Após quatorze dias da colagem de cada grupo, realizou-se o teste de resistência ao cisalhamento na máquina de ensaios universais EMIC DL 2000 (São José dos Pinhais, Brasil). Encontraram-se diferenças estatisticamente significantes entre os grupos Transbond Controle (11,93 ±3,53 MPa), Concise Controle (14,38 ± 7,81 MPa), Transbond Imediato (14,42 ± 5,16 MPa) e Transbond aberto por duas semanas e armazenado em geladeira (13,33 ±3,80 MPa) com os demais grupos (P<0.05). O grupo Concise aberto por duas semanas e armazenado em geladeira (2,19 ± 2,17 MPa), apresentou menor valor e o grupo Transbond Imediato (14,42 ± 5,16 MPa) o maior. Os grupos que apresentaram maior e menor quantidade de remanescente adesivo respectivamente foram o grupo Transbond aberto por quatro semanas e armazenado em temperatura ambiente (36,66 ± 29,53 mm²) e o grupo Concise Controle (1,42 ± 2,60 mm²). O armazenamento do TPSEP, à temperatura de 4ºC depois de ativado por até duas semanas, associado ao compósito Transbond XT (grupo T2G), parece não afetar os resultados na resistência ao cisalhamento, podendo ser usado com segurança. A associação do TPSEP, imediatamente após ativação, ao Transbond XT® apresentou excelentes valores de resistência ao cisalhamento (grupo TI, com 14,42 ± 5,16MPa), ocorrendo o oposto quando associado ao ConciseMR (grupo CI, com 4,76 ± 2,57MPa).Nos grupos onde o sistema autocondicionante estava aberto com duas semanas e associado com ConciseMR, bem como naqueles onde o tempo foi por quatro semanas, tanto associado com Transbond ou ConciseMR, os valores de resistência ao cisalhamento foram menores que o mínimo necessário, 6MPa (AU)

The goal of the authors of this study was to evaluate the degree of adhesion of the self-etching system (TPSEP) as the variation in the time and storage. They evaluated the shear bond strength and the Adhesive Remnant Index. 120 bovine incisors were divided into 12 groups with 2 controls and 10 working groups, were evaluated times and the kind of storage of the opened TPSEP. After 14 days each group, was subject to a shear bond strength test on universal testing machine EMIC DL 2000 (São José dos Pinhais, Brazil). Normality verification was performed using the Kolmogorov-Smirnov test, at a significance level of 0.05. Checked the normal distribution, the data were subjected to analysis of variance (ANOVA) and Tukey post hoc at the 0.05 significance level. The Pearson correlation test was applied to the variables. The intra class corroboration coefficient was used to evaluate the reliability of the IRA measures, (ICC = 0.92). Statistically significant differences were found between the groups Transbond Control (11.93 ± 3.53 MPa), Concise Control (14.38 ± 7.81 MPa), Transbond Immediate (14.42 ± 5.16 MPa) and Transbond activated for two weeks and storage in the refrigerator (13.33 ± 3.80 MPa) with the other groups (P < 0.05). The Group Concise activated for two weeks and storage in the refrigerator (2.19 ± 2.17 MPa), showed lowest value and the group Transbond Immediate (14.42 ± 5.16 MPa) the highest. The group that showed the highest and least amount of adhesive remnant respectively were: Transbond activated for four weeks storage in ambience temperature (36.66 ± 29.53 mm), and the Group Concise Control (1.42 ± 2.60 mm). TPSEP storage at 4° C, after activated for up to 2 weeks, associated with the Transbond composite XT (T2G) doesn't seem to affect the results on shear bond strength, and can be used safely.The Association of TPSEP immediately after the Transbond XT® chemical mixture presented excellent shear bond strength values (TI Group) (14.42 ± 5, 16MPa), the opposite when associated with the Concise ® (IC Group) (4.76 ± 2, 57MPa). In open groups with two weeks associated to Concise® and in groups with four weeks, the shear bond strength values were lower than the minimum considered necessary for the literature, 6MPa (AU)

Tensile bond strength of different universal adhesive systems to lithium disilicate ceramic.

BACKGROUND: Today, many adhesive systems with different coupling agents for tooth structures and restorative materials are available. The purpose of this in vitro study was to evaluate the tensile bond strength (TBS) of different universal adhesive systems to etched lithium disilicate ceramic. METHODS: The authors etched and bonded 96 disk-like lithium disilicate ceramic specimens (IPS e.max CAD, Ivoclar Vivadent) with 4 different adhesive bonding systems to Plexiglas tubes filled with a composite resin. The authors stored the specimens in water at 37°C for 3 days without thermal cycling or for 30 or 150 days with 7,500 or 37,500 thermal cycles between 5°C and 55°C, respectively. Then, all specimens underwent TBS testing. The authors performed statistical analysis by using Kruskal-Wallis and Wilcoxon tests with a Bonferroni-Holm correction for multiple testing. RESULTS: Initially, all adhesive systems exhibited considerable TBS, but some showed a significant reduction after 30 days of storage. After 3, 30, and 150 days, the Monobond Plus and Multilink Automix (Ivoclar Vivadent) silane-containing adhesive system showed significantly higher bond strengths to lithium disilicate ceramic than did the other universal adhesive systems, some of which do not contain silanes. CONCLUSIONS: The bond strength to lithium disilicate ceramic is affected significantly by the adhesive bonding system used. PRACTICAL IMPLICATIONS: Universal adhesive systems that do not contain a silane should be avoided for bonding lithium disilicate ceramic restorations because of their inferior bond strength.

Dental students' ability to assess their performance in a preclinical restorative course: comparison of students' and faculty members' assessments.

Dental education consists of both theoretical and practical learning for students to develop competence in treating patients clinically. When dental students encounter practical courses in their first year as a new educational experience, they must also learn to evaluate themselves. Self-evaluation is an essential skill to learn for dental professionals to keep increasing their competence over the course of their careers. The aim of this study was to compare the assessment scores of second- and third-year dental students and the faculty in two consecutive preclinical practical exams in restorative dentistry courses in a dental school in Turkey. Faculty- and student-assigned scores were calculated from two consecutive preclinical examinations on tooth restorations performed on both artificial casts and phantom patients. The students were formally instructed on grading procedures for tooth preparations, base and restoration placement, and polishing criteria. After each step, each item was assessed by faculty members, the student, and another student. The results indicated that the initial differences between second-year students' assessments of their own preclinical practical ability and that of the faculty decreased among the third-year students. Self-evaluation scores did not indicate whether the third-year students tended to over- or underestimate the quality of their own work. However, the second-year students not only overestimated themselves but thought they were above average. The results point to the need to develop students' self-insight with more exercises and practical training.

Evaluation of the bond strengths of 3 endodontic cements via push-out test.

In this study, the push-out method was used to evaluate the bond strengths of 3 types of endodontic cements according to their composite base: methacrylate, epoxy resin, and an experimental copaiba oil resin. The study hypothesis was that the methacrylate-based and experimental cements would have bond strengths equal to or greater than that of the epoxy resin-based cement. Thirty bovine tooth roots, 18 mm long, were divided into 3 groups (n = 10) based on the chosen cement treatment. After treatment, the specimens were sectioned and submitted to a push-out test. Results showed that there was no statistically significant difference (P < 0.05) between the cements used or between the middle and apical thirds of the roots. It could be concluded that the tested cements had satisfactory and similar bond strengths to dentin.

Shear bond strength of different adhesives tested in accordance with DIN 13990-1/-2 and using various methods of enamel conditioning.

OBJECTIVES: The purpose of this work was to analyze the shear bond strength (SBS) of different adhesives for orthodontic brackets in accordance with DIN 13990-1/-2, also taking into consideration potential effects arising from different scenarios of enamel conditioning and specimen storage. MATERIALS AND METHODS: A total of 390 experiments were performed, with groups of 10 specimens subjected to identical treatments. Three adhesives were tested: Transbond™ XT (3M Unitek, Monrovia, USA), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Fuji Ortho LC (GC Europe, Leuven, Belgium). SBS was evaluated separately at the bracket-adhesive and adhesive-enamel interfaces, as well as the total (enamel-adhesive-bracket) interface. The brackets were metal brackets for upper right central incisors (Discovery® from Dentaurum, Ispringen, Germany). A universal testing machine (Zwick Z010, Ulm, Germany) was used for testing the SBS after 15 min, or after storage in distilled water at 37 °C for 24 h, or after 24 h followed by 500 thermocycles alternating between 5 and 55 °C. RESULTS: Transbond™ XT produced the highest levels of SBS. The least favorable performance was observed with Fuji Ortho LC after enamel conditioning with 10 % polyacrylic acid. Thermocycling did not have a significant influence. CONCLUSION: Transbond™ XT and Beauty Ortho Bond (but not Fuji Ortho LC) yielded levels of SBS adequate for clinical application (≥ 7 MPa).

Shear bond strength of porcelain veneers rebonded to enamel.

In this laboratory research, shear bond strength (SBS) and mode of failure of veneers rebonded to enamel in shear compression were determined. Three groups (A, B, and C; n=10 each) of mounted molar teeth were finished flat using wet 600-grit silicon carbide paper, and 30 leucite-reinforced porcelain veneers (5.0 × 0.75 mm) were air abraded on the internal surface with 50 µm aluminum oxide, etched with 9.5% hydrofluoric acid, and silanated. The control group (A) veneer specimens were bonded to enamel after etching with 37% phosphoric acid using bonding resin and a dual cure resin composite cement. Groups B and C were prepared similarly to group A with the exception that a release agent was placed before the veneer was positioned on the prepared enamel surface and the resin cement was subsequently light activated. The debonded veneers from groups B and C were placed in a casting burnout oven and heated to 454°C/850°F for 10 minutes to completely carbonize the resin cement and stay below the glass transition temperature (Tg) of the leucite-reinforced porcelain. The recovered veneers were then prepared for bonding. The previously bonded enamel surfaces in group B were air abraded using 50 µm aluminum oxide followed by 37% phosphoric acid etching, while group C enamel specimens were acid etched only. All specimens were thermocycled between 5°C and 55°C for 2000 cycles using a 30-second dwell time and stored in 37°C deionized water for 2 weeks. SBS was determined at a crosshead speed of 1.0 mm/min. SBS results in MPa for the groups were (A) = 20.6±5.1, (B) = 18.1±5.5, and (C) = 17.2±6.1. One-way analysis of variance indicated that there were no significant interactions (α=0.05), and Tukey-Kramer post hoc comparisons (α=0.05) detected no significant pairwise differences. An adhesive mode of failure at the enamel interface was observed to occur more often in the experimental groups (B = 40%, C = 50%). Rebonding the veneers produced SBS values that were not significantly different from the control group. Also, no significant difference in SBS values were observed whether the debonded enamel surface was air abraded and acid etched or acid etched only.

Influence of prosthesis type and retention mechanism on complications with fixed implant-supported prostheses: a systematic review applying multivariate analyses.

PURPOSE: To identify the influence of fixed prosthesis type on biologic and technical complication rates in the context of screw versus cement retention. Furthermore, a multivariate analysis was conducted to determine which factors, when considered together, influence the complication and failure rates of fixed implant-supported prostheses. MATERIALS AND METHODS: Electronic searches of MEDLINE (PubMed), EMBASE, and the Cochrane Library were conducted. Selected inclusion and exclusion criteria were used to limit the search. Data were analyzed statistically with simple and multivariate random-effects Poisson regressions. RESULTS: Seventy-three articles qualified for inclusion in the study. Screw-retained prostheses showed a tendency toward and significantly more technical complications than cemented prostheses with single crowns and fixed partial prostheses, respectively. Resin chipping and ceramic veneer chipping had high mean event rates, at 10.04 and 8.95 per 100 years, respectively, for full-arch screwed prostheses. For "all fixed prostheses" (prosthesis type not reported or not known), significantly fewer biologic and technical complications were seen with screw retention. Multivariate analysis revealed a significantly greater incidence of technical complications with cemented prostheses. Full-arch prostheses, cantilevered prostheses, and "all fixed prostheses" had significantly higher complication rates than single crowns. A significantly greater incidence of technical and biologic complications was seen with cemented prostheses. CONCLUSION: Screw-retained fixed partial prostheses demonstrated a significantly higher rate of technical complications and screw-retained full-arch prostheses demonstrated a notably high rate of veneer chipping. When "all fixed prostheses" were considered, significantly higher rates of technical and biologic complications were seen for cement-retained prostheses. Multivariate Poisson regression analysis failed to show a significant difference between screw- and cement-retained prostheses with respect to the incidence of failure but demonstrated a higher rate of technical and biologic complications for cement-retained prostheses. The incidence of technical complications was more dependent upon prosthesis and retention type than prosthesis or abutment material.