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ABSTRACT Objective: To compare the pulp vitality of deciduous molars before and after selective caries removal (SCR) or nonselective caries removal to hard dentin (NSCR) over one year, using oxygen saturation percentage (%SaO2). Material and Methods: Deciduous molars with deep occlusal/proximal-occlusal caries lesions were randomized to SCR (n=22) or NSCR groups (n=22). After the caries removal, the teeth were protected with calcium hydroxide cement and restored with composite resin (Filtek Z250). The pulp condition diagnosis was evaluated at baseline, immediately after caries removal, and follow-up (7 days, 1-, 6- and 12-months) by %SaO2. Pulp exposure and pulp necrosis were primary outcomes, and %SaO2 was secondary. Results: Intraoperative pulp exposure occurred in four teeth of the NSCR group (18.2%) and one tooth of the SCR group (4.5%) (p>0.05). Two cases of pulp necrosis occurred in the NSCR group (10%). No difference in %SaO2 pulp was observed in the inter-and intragroup comparison over time (p>0.05). Conclusion: Advantageously, the %SaO2 minimizes preoperatory pulp vitality diagnosis subjectivity before SCR/ NSCR treatments. Furthermore, the pilot study results suggest the pulp response of deciduous molars, when evaluated by clinical, radiographic, and pulp %SaO2 seems not to differ between teeth treated with SCR or NSCR.

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Aim: Evaluating the resin-dentin bond strength of Class II conventional and bulk-fill composite restorations, using different cavity sizes before and after aging. Methods: Seventy-five human molars were distributed into groups according to the buccolingual width of the cavities, conservative (n=25) and extended (n=50). They were divided according to the restorative material: conventional (Z100/control group) or bulk-fill resin composites (Filtek Bulk Fill/FBF; Tetric N Ceram Bulk Fill/TNCBF; Filtek Bulk Fill Flow/FBFF; Surefill SDR flow/SDR). The restored teeth were sectioned on sticks (n=50 per restorative materials + width cavities group), half were stored in Water/Ethanol 75% for 30 days and the other half were submitted to the immediate microtensile bond strength (µTBS) test. Data were analyzed applying the Three-Way Analysis of Variance (ANOVA), Bonferroni test, test t, and Weibull analyses (p<0.05). Results: SDR and FBF presented lower µTBSvalues for extended preparation when compared to the conservative preparation, before aging. After aging, only for the FBFF, a decrease in the µTBSvalues was observed. Comparing the µTBSvalues, before and after aging, the SDR demonstrated lower µTBSvalues after aging when the conservative cavity was used. A decrease in the µTBSvalues was observed for the Z100, the FBF and, the FBFF, after aging, when the extended cavity was used. Conclusion: The effect of cavity preparation and aging on the resin-dentin of Class II is material dependent. Most of the bulk-fill resin composites evaluated presented a similar performance to the conventional resin composites for all the conditions of this study

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In the last decades, the move of medicine towards minimally invasive treatments is notorious and scientifically grounded. As dentistry naturally follows in its footsteps, minimal access preparation have also becume a trend topic in the endodontic field. This procedure aims to maximize preservation of dentine tissue backed up by the idea that this is an effective way to reduce the incidence of post-treatment tooth fracture. However, with the assessment of the body of evidence on this topic, it is possible to observe some key points (a) the demand for nomenclature standardization, (b) the requirement of specific tools such as ultra-flexible instruments, visual magnification, superior illumination, and three-dimensional imaging technology, (c) minimally invasive treatment does not seem to affect orifice location and mechanical preparation when using adequate armamentarium, but it (d) may impair adequate canal cleaning, disinfection and filling procedures, and also (e) it displays contradictory results regarding the ability to increase the tooth strengthen compared to the traditional access cavity. In spite of that, it is undeniable that methodological flaws of some benchtop studies using extracted teeth may be responsible for the conflicting data, thus triggering the need for more sophisticated devices/facilities and specifically designed research in an attempt to make clear the role of the access size/design on long-term teeth survival. Moreover, it is inevitable that a clinical approach such as minimal endodontic access cavities that demands complex tools and skilled and experienced operators bring to the fore doubts on its educational impact mainly when confronted with the conflicting scientific output, ultimately provoking a cost-benefit analysis of its implementation as a routine technique. In addition, this review discusses the ongoing scientific and clinical status of minimally invasive access cavities aiming to input an in-depth and unbiased view over the rationale behind them, uncovering not only the related conceptual and scientific flaws but also outlining future directions for research and clinical practices. The conclusions attempt to skip from passionate disputes highlighting the current body of evidence as weak and incomplete to guide decision making, demanding the development of a close-to-in situ laboratory model or a large and well-controlled clinical trial to solve this matter.

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Antimicrobial photodynamic therapy (aPDT) is an adjunct to a selective caries removal (SCR) technique for deep caries lesion treatment. The knowledge about chemical and structural changes affecting the remaining dentin surface after the use of this therapy is still unknown. OBJECTIVE: to answer the following question: Does the SCR technique in combination with aPDT affect the clinical performance of adhesive restorations in deep carious lesions of primary or permanent teeth? STUDY DESIGN: a systematic review was conducted. Five databases, supplemented by trial registers, google scholar, manual search, personal communications, and grey literature were investigated. Randomized clinical trials were included. Two independent reviewers selected the studies, extracted qualitatively the data, and evaluated the risk of bias (using Cochrane Collaboration's tool and Robot Reviewer program). The certainty of the evidence was accessed based on The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. A meta-analysis of comparable data was performed with RevMan software 5.3. RESULTS: A total of 39 articles and 3 studies were found. The final selection included 3 articles with a total of 82 participants. No studies were found on permanent teeth. The studies presented low risk of bias. Considering the treatment in the experimental (SCR + aPDT) or control groups (SCR), no difference on clinical performance of adhesive restorations in deep caries of primary teeth was observed after 6 months (p = 0.78; CI -0.01 (-0.09, 0.07)) or 12 months (p =0.75; CI -0.02 (-0.12, 0.08)). All outcomes presented moderate certainty of evidence mainly due to the small sample size that downgrade the GRADE scores. CONCLUSIONS: based on moderate certainty of the evidence, the clinical use of aPDT as an adjuvant of SCR has potential indication for treatment in deep caries of primary teeth. However, studies with more follow up and on permanent teeth are missing with the necessity for further research.

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O objetivo deste trabalho foi comparar, in vitro, as características e qualidade do acabamento de superfície em dentes bovinos, através da análise de rugosidade superficial e análise de imagens em Microscopia Eletrônica de Varredura (MEV). Apesar de amplamente utilizadas, as pontas diamantadas apresentam limitações como baixa durabilidade e suas repetidas esterilizações causam diminuição da capacidade de corte. Com o surgimento das pontas odontológicas de diamante CVD (Chemical Vapor Deposition), sua indicação tem sido ampliada como alternativa, pois associadas a aparelhos de ultrassom apresentam boa resistência ao desgaste. Oitenta dentes bovinos foram selecionados para este estudo e foram divididos em oito grupos de acordo com o tipo de ponta utilizada para confecção do desgaste do preparo protético: Grupo I ­ ponta diamantada KG nº2135 acoplada em alta rotação (AR) grupo controle; Grupo II - ponta diamantada KG nº2135 (AR), ponta diamantada CVDentus CR4 acoplada em ultrassom (US); Grupo III - ponta diamantada KG nº2135 (AR), ponta diamantada CVDentus CR4 seguida da ponta CR4U, acopladas em US; Grupo IV ­ ponta diamantada KG nº2135 (AR), ponta diamantada TR18-H CVDentus AR; Grupo V ­ ponta diamantada KG nº2135 acoplada em AR, seguido de broca carbide multilaminada 30 lâminas de acabamento de preparo, acopladas em baixa rotação; Grupo VI­ ponta diamantada KG nº2135 (AR), seguido de broca carbide multilaminada 30 lâminas e finalização com ponta de borracha, Grupo VII - ponta diamantada KG nº2135 (AR), broca CVDentus TR18-H (AR), ponta diamante CR4-U (CVDentus) (US); Grupo VIII - ponta diamantada KG nº2135 (AR), ponta diamante CR4 (CVDentus), ponta diamante T1-F (US). Após confecção dos preparos, 10 amostras de dentes de cada grupo foram analisados quanto a rugosidade em rugosímetro e duas amostras de cada grupo serão avaliadas por Microscópio eletrônico de varredura (MEV). Os dados referentes à avaliação quantitativa (rugosidade superficial) foram submetidos à análise estatística. (AU)

The objective of this work was to compare, in vitro, the characteristics and quality of the surface finish in bovine teeth, through the analysis of surface roughness and image analysis in Scanning Electron Microscopy (SEM). Despite being widely used, diamond burs have limitations such as low durability and their repeated sterilization causes a decrease in cutting capacity. With the emergence of CVD (Chemical Vapor Deposition) diamond dental tips, their indication has been expanded as an alternative, because associated with ultrasound devices they present good resistance to wear. Eighty bovine teeth were selected for this study and were divided into eight groups according to the type of tip used to make the prosthetic preparation wear: Group I ­ diamond tip KG nº2135 coupled in high rotation (HR) control group; Group II - diamond bur KG nº2135 (AR), diamond bur CVDentus CR4 coupled to ultrasound (US); Group III - diamond bur KG nº2135 (AR), diamond bur CVDentus CR4 followed by the CR4U bur, coupled in US; Group IV ­ diamond bur KG nº2135 (AR), diamond bur TR18-H CVDentus AR; Group V ­ diamond bur KG nº2135 coupled in AR, followed by a multilaminated carbide bur 30 preparation finishing blades, coupled in low rotation; Group VI ­ diamond bur KG nº2135 (AR), followed by a 30-blade multi-blade carbide bur and finishing with a rubber tip, Group VII ­ diamond bur KG nº2135 (AR), CVDentus bur TR18-H (AR), diamond bur CR4-U (CVDentus) (US); Group VIII - diamond bur KG nº2135 (AR), diamond bur CR4 (CVDentus), diamond bur T1-F (US). After preparation of the preparations, 10 samples of teeth from each group were analyzed for roughness in a rugosimeter and two samples from each group will be evaluated by Scanning Electron Microscope (SEM). Data referring to the quantitative evaluation (surface roughness) were subjected to statistical analysis. (AU)

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Objective: This study aimed to determine the push-out-bond-strength(PBS) of mineral trioxide aggregate (BIOMTA+) and calcium-enriched-mixture-cement (CEM) in retrograde cavities prepared using Er: YAG laser and stainless-steel bur. Material and Methods: The root canals of 60 extracted single-rooted human teeth were prepared, filled and their apical portion of 3-mm were resected using a diamond bur and randomly divided into four groups according to technique of retrograde preparation and filling material as follows(n=15): Group1: bur/ BIOMTA+ ,Group2: bur/ CEM, Group3: Er:YAG laser/ BIOMTA+, Group4: Er:YAG laser/ CEM. PBS test were performed to specimens and failure modes were evaluated. The data were statistically analyzed with ANOVA, Post-Hoc Tukey and t tests (p< 0.05). Results: CEM was exhibited higher than bond strength compared to BIOMTA+ in retrograde cavity prepared using laser (p= 0.021) and BIOMTA+ in retrograde cavity prepared using bur was exhibited higher than bond strength compared to in retrograde cavities prepared using laser (p= 0.024). Failure modes were dominantly cohesive in all groups tested and one representative specimen each failure mode was examined in SEM and the general characteristics of the failure modes were confirmed. Conclusion: With in the limitations of the present study, when used CEM, Er: YAG laser-assisted retrograde cavity preparation positively affected the bond strength values compared to BIO MTA+. Considering its optimal adhesion, the calcium-enriched-mixture-cement (CEM) might be a good option as a filling material in retrograde cavities in clinical use. (AU)

Objetivo: O objetivo deste estudo foi determinar a força de união (PBS) de cimento de agregado trióxido mineral (BIO MTA+) e cimento enriquecido com cálcio (CEM) em preparos cavitários retrógrados realizados com: Laser Er-YAG e brocas de aço inoxidável. Material e Métodos: Canais radiculares de 60 dentes unirradiculares extraídos foram preparados, preenchidos e 3 mm de suas porções apicais foram ressecadas usando uma broca diamantada e divididos randomicamente em quatro grupos de acordo com a técnica de preparação retrógrada e o material de preenchimento (n=15): Grupo 1: Broca/BIO MTA+, Grupo 2: Broca/CEM, Grupo 3: Laser Er-YAG/BIO MTA+, Grupo 4: Laser Er-YAG/CEM. O teste de PBS foi realizado para as amostras e os modelos de falha foram avaliados. Os dados foram analisados estatisticamente pelos testes de ANOVA, Post-Hoc Tukey e testes t (p< 0.05). Resultados: CEM apresentou maior força de união que BIO MTA+ em cavidades retrógradas preparadas com laser (p= 0.021) e BIO MTA+ em cavidades retrógradas preparadas com brocas apresentou maior força de união quando comparado à cavidades retrógradas preparadas com laser (p= 0.024). Os modelos de falha foram predominantemente coesos em todos os grupos testados e um espécime representativo de cada modelo de falha foi examinado em MEV e as características gerais dos modelos de falha foram confirmadas. Conclusão: Com as limitações do presente estudo, quando usou-se CEM, o preparo de cavidades retrógradas através de Laser Er-YAG afetou positivamente os valores da força de união quando comparados com BIO MTA+. Considerando sua ótima adesão, o cimento enriquecido com cálcio (CEM) pode ser uma boa opção como um material de preenchimento em cavidades retrógradas no uso clínico.

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The clinical success of tooth-colored indirect restorations has been confirmed in several studies. However, inlays and onlays restorations in Class II cavities with deep gingival margins can still be considered a clinical challenge. With the purpose of facilitating the execution of the operative procedures in intrasulcular margins and reducing the risk of restorative failures, the technique of cervical margin relocation has been explored as a noninvasive alternative to surgical crown lengthening. This work aims at discussing through a case report the biomechanical, operative and biological aspects in the treatment of teeth with deep gingival margins. Therefore, given the therapy applied in the clinical case presented, it is concluded that the cervical margin relocation with composite resin is advantageous since it eliminates the need for surgery, allowing the implementation of indirect restorations in fewer clinical sessions, not causing damage to periodontal tissues once it provided good finishing and polishing with the establishment of a correct emergence profile, allowing flawless maintenance of gingival health after one year. (AU)

Sucesso clínico das restaurações indiretas livres de metal tem sido confirmado em diversos estudos. No entanto, restaurações parciais indiretas em cavidades do tipo classe II com margens profundas ainda podem ser consideradas um desafio clínico. Com a proposta de facilitar a execução dos procedimentos operatórios em margens intra-sulculares e reduzir a ocorrência de falhas, a técnica de elevação da margem gengival em resina composta tem sido explorada como alternativa não invasiva à cirurgia de aumento de coroa clínica. Este trabalho tem a intenção de discutir através de um relato de caso clínico os aspectos biomecânicos, operatórios e biológicos no tratamento de dentes com margens cervicais profundas. Sendo assim, conclui-se que a técnica de elevação da margem gengival com resina composta é vantajosa, pois elimina a necessidade de cirurgia permitindo a execução de restaurações indiretas em menos sessões clínicas, não gerando danos aos tecidos periodontais, desde que haja um bom acabamento e polimento, com estabelecimento de um correto perfil de emergência. (AU)

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Aim: To investigate restorative decisions made by dentists and to examine what demographic characteristics are associated with the decisions for managing approximal and occlusal lesions. Methods: A questionnaire was randomly sent to 900 Palestinian dentists. It noted the demographic details of the dentists and the years of experience. The questionnaire evaluated the respondents for their treatment decisions regarding approximal and occlusal carious lesions. The data was analyzed using the IBM SPSS statistics for windows. The associations between gender and years of experience of the respondents and their restorative decisions were assessed. Results: The response rate was 58.2%. For occlusal carious lesions, 93.9% of the respondents would postpone operative treatment until the lesion was in dentine (grade 3 to 5). For approximal lesions, intervention was deemed appropriate by 92.6% of the respondents when there was radiographic evidence of a carious lesion reaching the DEJ or deeper. Around 53% preferred to prepare approximal lesions according to the traditional principles of cavity preparation. For both approximal and occlusal lesions, the participants opted for resin composites. Statistically, there was a significant association between the restorative decisions with the years since graduation and gender. Conclusion: The study showed variations between the treatment decisions of Palestinian dentists. The subjects chose conservative treatment plans but still adhered to traditional learned practices especially when cavity preparation for approximal lesions was concerned. The years since graduation and gender played a significant role in the choice of treatment opted for. Resin composites seemed to be a popular choice for treatment

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This study proposed the development of a protocol for class-II preparations with demineralized gingival margins for the improvement of the longevity of restorations. Evidence sources such as location/color/surface hardness/width of demineralized gingival margin with enamel/demineralized enamel (DE)/dentin/cementum were reviewed based on methodological studies and systematic reviews. A decision tree protocol was developed with criteria (i) lesion location: demineralized gingival margins in enamel must be removed, but if close to cementoenamel-junction, color should be evaluated. (ii) Color: yellow/brown lesions must be removed, but if white/opaque, then the surface hardness should be evaluated. (iii) Surface hardness: soft/demineralized gingival margin must be removed, but if adequately hard, width should be evaluated. (iv) Width: lesions less than half-enamel thickness and impenetrable by an explorer, remineralization is possible and the lesion does not need to be removed. A decision tree protocol was set up with the current available literature. Further continued investigations will be needed for the appropriate protocol updates.

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The teeth weakening due to the preparation of class II mesio-occluso-distal cavities is a challenge for the clinician. The objective of this study was to evaluate the molars fracture resistance with class II mesio-occluso distal cavities restored with different restorative techniques and materials. Forty extracted molars were divided into 5 groups: Group 1 ­ intact healthy teeth (positive control); Group 2 ­ unrestored teeth with mesio-occluso distal class II cavities (negative control); Groups 3 to 5 ­ restored teeth with standardized dimensions. In groups 3 to 5, the cavities were restored with flow resin only, flow resin coated with a nano-hybrid resin, and nano-hybrid resin only, respectively. All specimens were tested for resistance to fracture using an axial compressive load, a metallic sphere measuring 8 mm in diameter on a universal testing machine EMIC DL-2000. A 10 kN load cell operated at a speed of 5 mm/min until the tooth fracture. Data were subjected to analysis of variance and Tukey's tests (α = 0.05). Group 3 showed higher fracture strength (2243.1 ± 473.7N) when compared to groups 2, 4 and 5. This difference was statistically significant (p<0.05). The fracture strength of teeth restored with flow mesio occluso-distal restorations was similar to that of intact natural teeth. (AU)

O enfraquecimento dos dentes devido às preparações de cavidades mesio-ocluso-distal é um desafio para o clínico. O objetivo deste estudo foi avaliar a resistência à fratura de molares com cavidades mesio-ocluso-distais classe II restauradas com diferentes técnicas e materiais restauradores. Quarenta molares extraídos foram divididos em 5 grupos: Grupo 1 ­ dentes saudáveis intactos (controle positivo); Grupo 2 ­ dentes não restaurados com cavidades mesio-occluso-distais classe II (controle negativo); Grupos 3 a 5 ­ dentes restaurados com dimensões padronizadas. Nos grupos 3 a 5, as cavidades foram restauradas apenas com resina flow, resina flow recoberta com uma resina nanohíbrida e somente resina nano-híbrida, respectivamente. Todas as amostras foram testadas quanto à resistência à fratura usando uma carga compressiva axial, usando uma esfera metálica medindo 8 mm de diâmetro em uma máquina de teste universal EMIC DL-2000. Uma célula de carga de 10 kN operava a uma velocidade de 5 mm/min até a fratura do dente. Os dados foram submetidos à análise de variância e testes de Tukey (α = 0,05). O grupo 3 apresentou maior resistência à fratura (2243,1 ± 473,7N) quando comparado aos grupos 2, 4 e 5. Essa diferença foi estatisticamente significante (p <0,05). A resistência à fratura dos dentes restaurados com resina flow foi semelhante à dos dentes naturais intactos. (AU)

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In the last decade, several access cavity designs involveing minimal removal of tooth tissue have been described for gaining entry to pulp chambers during root canal treatment. The premise behind this concept assumes that maximum preservation of as much of the pulp chamber roof as possible during access preparation would maintain the fracture resistance of teeth following root canal treatment. However, the smaller the access cavity, the more difficult it may be to visualize and debride the pulp chamber as well as locate, shape, clean and fill the canals. At the same time, a small access cavity may increase the risk of iatrogenic complications as a result of poor visibility, which may have an impact on treatment outcome. This study aimed to critically analyse the literature on minimal access cavity preparations, propose new nomenclature based on self-explanatory abbreviations and highlight the areas in which more research is required. The search was conducted without restrictions using specifics terms and descriptors in four databases. A complementary screening of the references within the selected studies, as well as a manual search in the highest impact journals in endodontics, namely International Endodontic Journal and Journal of Endodontics, was also performed. The initial search retrieved 1831 publications. The titles and abstracts of these papers were reviewed, and the full text of 94 studies was assessed. Finally, a total of 28 studies were identified as evaluating the influence of minimally invasive access cavity designs on the fracture resistance of teeth and on the different stages of root canal treatment (orifice location, canal shaping, canal cleaning, canal filling and retreatment). Overall, the studies had major methodological drawbacks and reported inadequate and/or inconclusive results on the utility of minimally invasive access preparations. Furthermore, they offered limited scientific evidence to support the use of minimally invasive access cavities to improve the outcome of root canal treatment and retreatment; they also provided little evidence that they preserved the fracture resistance of root filled teeth to a greater extent than traditional access cavity preparations. It was concluded that at present, there is a lack of supporting evidence for the introduction of minimally invasive access cavity preparation into routine clinical practice and/or training of undergraduate and postgraduate students.

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ABSTRACT: The objective of the study was to evaluate marginal adaptation of Class II mesial-occlusal-distal (MOD) restorations before and after thermo-mechanical loading and volumetric shrinkage of the bulk-fill vs conventional composite resin. For marginal adaptation assessment, 24 Class II MOD cavities with cervical margins extending 1.0 mm below (distal) and 1.0 mm beyond (mesial) the cement-enamel junction were prepared in extracted human molars. The teeth were filled as follows: Group A - bulk-fill with SureFil SDR flow (first increment, 4 mm; second increment, 2 mm); Group B - bulk-fill with SureFil SDR flow as a base (first increment, 4 mm) and covered with the conventional nanohybrid composite Esthet-X HD (second increment, 2 mm); and Group C - incrementally filled with Esthet-X HD. Marginal adaptation was evaluated by scanning electron microscopy before and after thermomechanical loading (240,000 loading cycles and simultaneous 600 thermal cycles). To evaluate volumetric polymerization shrinkage, a semi-spherical mold was filled with the tested composites and placed in an AccuVol device after light curing. Both before and after loading, marginal adaptation in cervical dentin was superior (p < 0.05) for Groups A and B compared with Group C. In cervical enamel, Group B showed better marginal adaptation than Group C, and Group A presented intermediary results, between Groups B and C. Furthermore, bulk-fill flow resulted in greater shrinkage than Esthet-X HD. A significant improvement of marginal adaptation was observed when bulkfill flow was used instead of conventional composite resin both before and after thermomechanical loading. However, the bulk-fill flow presented higher volumetric polymerization shrinkage than the conventional composite.

RESUMEN: El objetivo de este trabajo consistió en evaluar la adaptación marginal de las restauraciones mesiales-oclusales-distales (MOD) de Clase II antes y después de la carga termo-mecánica y la contracción volumétrica de la carga compuesta de resina "bulk-fill" en comparación con resina convencional. Para la evaluación de adaptación, se prepararon 24 cavidades MOD de Clase II en molares humanos extraídos, los que se restauraron de la siguiente manera: Grupo A: restaurado con resina fluida Bulk-Fill SureFilSDR (primer incremento, 4 mm; segundo incremento, 2 mm); Grupo B: restaurado con resina fluida Bulk-Fill SureFil SDR (primer incremento, 4 mm) y cubierto con resina compuesta nanohíbrida Esthet-X HD (segundo incremento, 2 mm); y Grupo C - rellenado incrementalmente con Esthet-X HD. La adaptación marginal se evaluó mediante microscopía electrónica de barrido antes y después de la carga termomecánica (240.000 ciclos de carga y 600 ciclos térmicos simultáneos). Para evaluar la contracción volumétrica de la polimerización, se llenó un molde semiesférico con los compuestos probados y se colocó en un dispositivo AccuVol después del fotopolimerización. Tanto antes como después de la carga, la adaptación marginal en la dentina cervical fue superior (p <0,05) para los grupos A y B en comparación con el grupo C. En el esmalte cervical, el grupo B mostró una mejor adaptación marginal que el grupo C, y el grupo A presentó resultados intermedios, entre Grupos B y C. Se observó una mejora significativa de la adaptación marginal al utilizar la resina fluida Bulk-Fill en lugar de resina compuesta convencional tanto antes como después de la carga termomecánica. Sin embargo, la resina fluida 'Bulk-Fill' presentó una mayor contracción volumétrica de polimerización que el compuesto convencional.

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Introduction: To prevent the shrinkage stresses produced during polymerization, composite resins of low polymerization shrinkage were developed. Objective: To evaluate the microtensile bond strength in class I cavities restored by acid-etching the cavosurface angle and with composite resins indicated for posterior teeth. Material and method: 48 healthy molars were selected and divided into six groups (n = 8), considering that the cavosurface enamel of three groups was etched with 35% phosphoric acid. The teeth were restored with the Clearfil SE Bond adhesive system and Filtek Z350 XT, Empress Direct, and Charisma Diamond composite resins, which were light-cured for 40 seconds. After 24 hours, the teeth were taken to a cutting machine, which produced sections in the buccolingual and mesiodistal directions. This resulted in toothpicks of 0.9×0.9 mm that were taken to the universal testing machine for the microtensile bond strength test. Statistical analysis was performed with ANOVA and Tukey's test (p < 0.05). Result: There was no statistically significant difference between the groups evaluated. Conclusion: Acid-etching the cavosurface angle did not affect the performance of restorations, probably due to the adhesive system used.

Introdução: Com o intuito de se evitar as tensões geradas durante a contração de polimerização das resinas compostas, foram desenvolvidas as resinas compostas de baixa contração de polimerização. Objetivo: Avaliar a resistência à microtração em cavidades classe I restauradas com tratamento ácido do ângulo cavo superficial e resina composta indicada para dentes posteriores. Material e método: Foram selecionados 48 molares hígidos que foram divididos em 6 grupos (n=8), sendo que 3 desses tiveram o esmalte cavo superficial condicionado com ácido fosfórico a 35%. Os dentes foram restaurados com o sistema adesivo Clearfil SE Bond e as resinas compostas Filtek Z350 XT, Empress Direct e Charisma Diamond, fotoativadas por 40 segundos. Após 24 horas, os dentes foram levados para máquina de corte, na qual foram realizados cortes no sentido vestíbulo-lingual e no sentido mésio-distal obtendo - se palitos de 0,9×0,9 mm que foram levadas para a máquina de ensaio universal para a realização do teste de microtração. Para análise estatística foi realizado análise de variância e teste de Tuckey (p < 0,05). Resultado: Não houve diferença estatística significante entre os grupos avaliados. Conclusão: O condicionamento ácido do ângulo cavo superficial não influenciou no desempenho das restaurações provavelmente devido ao sistema adesivo utilizado.

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Objective: To evaluate the effect of cavity dimensions on the amount of microleakage in two different types of bulk-fill composite resins. Material and Methods: Forty class II cavities were prepared in the mesial and distal surfaces of human molars without any carious lesions. The samples were divided into 4 groups (n=10): Group 1: cavities with 3 mm of buccolingual width (known as the smaller cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 2: cavities with 6 mm of buccolingual width (larger cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 3: cavities with 3 mm of buccolingual width, filled with X-Tra Base composite resin; and Group 4: cavities with 6 mm of buccolingual width, filled with X-Tra Base composite. After the specimens were thermocycled for 500 cycles at 5/55°C, they were immersed in 1% methylene blue for 24 hours, and then cut into sections mesiodistally in the longitudinal axis of each tooth. Then, the samples were scored regarding the amount of dye penetration in two occlusal and gingival areas under a stereomicroscope (x32). Data was submitted to Kruskal- Wallis and Mann-Whitney tests. Results: The highest degrees of microleakage in larger cavities filled with X-Tra Base among the four groups. There was a significant statistic difference (p=0.012) between large and small cavities filled with X-Tra Base (Groups 3 and 4); however, there was no significant difference between the two cavity sizes of Tetric N-Ceram Bulk-filled groups. Conclusion: Microleakage of composite resins depends on the dimension of the cavity and the type of composite resin used.

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Abstract Extensive restorations in posterior teeth always bring doubts to the clinicians regarding the best protocol, mainly when structures of reinforcement were lost. Objective This study aimed to evaluate the effect of beveling on the fracture resistance and pattern of class II (MOD) restored teeth. Methodology Ninety human premolars were randomly assigned into 9 groups: CTR (control/sound); NC (cavity preparation, non-restored); RU (restored, unbeveled); RTB (restored, entire angle beveling); RPB (restored, partial/occlusal beveling); EC (endodontic access/EA, non-restored); EU (EA, unbeveled); ETB (EA, entire angle beveling); EPB (EA, partial/occlusal beveling). Teeth were restored with Esthet X resin composite and stored in distilled water for 24 h before the inclusion in PVC cylinders. The axial loading tests were performed with 500 kgF at 0.5 mm/min crosshead speed until fracture of the specimens. Fracture resistance and pattern were accessed and data were analyzed using one-way ANOVA and Tukey's HSD test (α=0.05). Results Mean (±SD) failure loads ranged from 136.56 (11.62) to 174.04 (43.5) kgF in the groups tested without endodontic access. For endodontically accessed teeth, fracture resistance ranged from 95.54 (13.05) to 126.51 (19.88) kgF. Beveling of the cavosurface angle promoted the highest fracture resistance values (p<0.05) and prevented catastrophic fractures. Conclusions Cavosurface angle beveling is capable of improving fracture resistance and pattern for both endodonticaly accessed and non-accessed teeth.

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The aim of this study was to evaluate how acid-etching of the cavosurface enamel in Class I resin composite restorations influences the bond strength to the pulpal wall and the restoration, Knoop microhardness and nanoleakage after thermomechanical aging. For this research 76 fresh human molars were selected and restored with Silorane or Clearfil SEBond/Z350XT composite divided in 4 groups (Silorane system restored with or without enamel cavosurface acid-etching and Clearfil SEBond/Z350XT with or without enamel cavosurface acid-etching). To induce artificial aging, samples were subjected to thermomechanical cycling through 200,000 and thermal cycling between 5 and 55 °C with 30 second filling and 15-second drainage steps. Microhardness and microtensile bond strength were evaluated in 32 teeth (n=8) each and nanoleakage evaluation was performed in 12 teeth (n=3). Samples restored by Clearfil SEBond/Z350 XT without cavosurface acid-etching showed significantly lower microtensile bond strength results. The resin composite Z350XT presented higher values of Knoop microhardness. It was observed little or no infiltration for Silorane groups and moderate infiltration for Clearfil SE Bond groups. Acid-etching of the cavosurface enamel during restoration procedure with Clearfil Se Bond resulted in a stronger bond after thermomechanical cycling. Silorane groups showed less infiltration than Clearfil SE Bond groups (AU)

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Se desarrolló un estudio observacional comparativo, durante la cual se trabajó con toda la población estudio, la que estuvo constituida por 38 terceros molares sanos recolectados luego de extracción por causas odontológicas justificadas y con el consentimiento de los respecti-vos pacientes, cuyas edades oscilaron entre 20 y 25 años; la misma se distribuyó en dos grupo A (19) y grupo B (19); con el propósito de comparar la adherencia de la resina 3MZ250 en cavidades clase I de Black, utilizando dos tipos de fresas jota cilíndricas, de estas una de grano fino y otra grueso, en terceros molares in vitro. La investigación se desarrolló en cuatro etapas obteniendo los siguientes resultados: se estableció que en el grupo A, la adhesión de la resina a la estructura dentaria requirió una mayor fuerza de tracción promediando 215,49 N para desprenderla; mientras que en el B resultó de 167,7 N. El análisis estadístico mediante la prueba T permitió establecer que la diferencia de la resistencia a la tracción de la resina entre los grupos A y B resultó significativa. El uso de fresas de grano fino en la conformación de las cavidades clase I de Black crea paredes más lisas que permiten una mejor adhesión de la resina a la estructura dentaria; por lo que resultan más resistentes ante fuerzas de tracción.

A comparative observational study was carried out including the entire study population of 38 healthy third molars collected after extraction for medically justified reasons and with the consent of the respective patients. The ages ranged were from 20 to 25 years. It was distribu-ted in two strata: group A (19) and group B (19) in order to compare the adherence of resin 3MZ250 in class I GV Black cavities by using two types of cylindrical dental burs brand jota, the one of fine grained and the other thick, in third molars in vitro. The research was develo-ped in four stages obtaining the following results: in group A, the adhesion of the resin to the dental structure required a higher tensile force averaging 215.49 N to detach and in group B was 167.7 N. Statistical analysis using the T test allowed establishing that the difference in the tensile strength of the resin between groups A and B was significant. The use of dental burs of fine grained in the formation of class I GV Black cavities creates smoother walls that allow a better adhesion of the resin to the dental structure; so they are more resistant to tensile forces.

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The aim of this study was to evaluate the effect of cavity preparation with Er:YAG laser on dentin adjacent to restorations submitted to cariogenic challenge in situ, by subsuperficial microhardness analysis. Bovine incisors were sectioned, flattened, and polished, resulting in 40 dentin slabs. The slabs were randomly assigned to four groups (n = 10), according to the cavity preparation method: I-high-speed handpiece (control); II-Er:YAG laser (160 mJ; 3 Hz); III-Er:YAG laser (260 mJ; 3 Hz); IV-Er:YAG laser (300 mJ; 3Hz). Cavities were restored with composite resin, and the specimens were fixed in intra-oral appliances, which were worn by 10 volunteers for 14 days for simulating cariogenic challenge in situ. During the experimental period, 20% sucrose solution was dripped over each specimen 6 times a day. Samples were removed, sectioned, and examined for subsuperficial Knoop microhardness at 100, 200, and 300 µm from the restoration and at 30 µm from dentin surface. Split-plot analysis of variance showed no significant difference among the cavity preparation techniques (p = 0.1129), among distances (p = 0.9030), as well as no difference in the interaction between the main factors (p = 0.7338). It was concluded that the cavity preparation with Er:YAG laser did not influence on dentin microhardness submitted to cariogenic challenge in situ.

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O objetivo deste estudo foi avaliar a resposta clínica e radiográfica do complexo dentino-pulpar após o uso de três materiais protetores pulpares na remoção seletiva de tecido cariado em molares decíduos. O desfecho primário foi o sucesso da resposta in vivo do complexo dentino-pulpar e o secundário compreendeu a medida da espessura de barreira dentinária. Foram selecionados 36 molares de crianças entre 5 e 8 anos de idade, de ambos os gêneros, que apresentavam lesões de cárie oclusais profundas sem alterações pulpares. Após a remoção seletiva os dentes foram randomizadamente divididos em três grupos: Cimento Hidróxido de Cálcio ­ HC (Grupo I); Agregado de Trióxido Mineral ­ MTA (Grupo II) e Cimento Portland - CP (Grupo III). Uma restauração final foi confeccionada com o Cimento de Ionômero de Vidro Modificado por Resina. O erro casual foi verificado através do Teste t pareado. O teste Qui-quadrado foi utilizado para se determinar as diferenças estatísticas significativas entre os grupos. As medidas radiográficas foram comparadas utilizando ANOVA, seguido do Teste de Tukey (P <0,05). O resultado primário obtido, através das avaliações clínicas e radiográficas, foi o sucesso da resposta in vivo do complexo dentino-pulpar com uma taxa de 97,2% de sucesso para a técnica. A verificação radiográfica da formação de barreira dentinária resultou numa espessura de 0,145 mm ± 0,125 para o HC; 0,115 mm ± 0,06 para o MTA e 0,155 mm ± 0,08 para o CP. Não houve diferença estatisticamente significativa entre os grupos. Conclui-se que os resultados clínicos e radiográficos foram satisfatórios e houve aumento da espessura de barreira dentinária em um período de 6 meses de acompanhamento. A remoção seletiva do tecido cariado é uma alternativa à remoção total de tecido e que independentemente do material protetor pulpar escolhido, o selamento hermético da cavidade é extremamente importante para o sucesso a longo prazo.(AU)

The aim of this study was to evaluate the clinical and radiographic response of the dentin-pulp complex after the use of three pulp capping materials after the selective caries removal in primary teeth. The primary and secondary outcomes respectively were the success of the in vivo response of the dentin-pulp complex and the measurement of the dentin barrier thickness. We selected 36 molars of children aged between 5 and 8 years, of both genders, who presented deep occlusal caries lesions without pulp alterations. After the selective removal, the teeth were randomly divided into three groups: Calcium Hydroxide Cement - HC (Group I); Mineral Trioxide Aggregate - MTA (Group II) and Portland Cement - PC (Group III). A final restoration was made with Resin Modified Glass Ionomer Cement. The casual error was verified through paired t-test. The chi-square test was used to determine significant statistical differences between groups. Radiographic measurements were compared using ANOVA, followed by Tukey's test (P <0.05). The primary outcome obtained through clinical and radiographic evaluations was the success of the in vivo response of the dentin-pulp complex with a 97.2% success rate for the technique. Radiographic verification of the formation of the dentin barrier resulted in a thickness of 0.145 mm ± 0.125 for HC; 0.115 mm ± 0.06 for MTA and 0.155 mm ± 0.08 for PC. There was no statistically significant difference between groups. In conclusion, both the clinical and radiographic results were satisfactory and the thickness of the dentin barrier increased during the 6 months of following-up period. Selective caries removal is an alternative to total caries removal and regardless of the pulp protective material chosen, hermetic sealing of the cavity is extremely important for long-term success.(AU)

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Introdução: uma complicação inerente a todas as resinas compostas é o stress gerado pela contração de polimerização. As resinas compostas da atualidade, após a polimerização, perdem entre 2% a 3% de todo o seu volume. Essa perda pode acarretar em alterações fortemente comprometedoras a nível micro e macroscópico. Objetivo: abordar a importância do uso de técnicas e manobras clínicas, que visam diminuir a contração de polimerização das resinas compostas, reduzindo seus efeitos na cavidade, para que se tenha um procedimento restaurador com elevado índice de sucesso clínico e boa aceitação pelos pacientes. Material e Métodos: foi realizada uma revisão da literatura por meio de uma busca bibliográfica nas seguintes bases de pesquisa online: PUBMED/MEDLINE, LILACS, BBO e SCIENCE DIRECT, através do rastreio de artigos relevantes publicados entre o período de 2000 a 2015. Resultados: comparando as formas de ativação dos compósitos, os compósitos fotopolimerizáveis possuem um menor escoamento e maior stress de contração se comparados a compósitos com ativação química, isso se dá devido à fotoativação que se destaca por ser uma reação rápida quando comparada a outros métodos, não dispondo de tempo para a resina se acomodar na cavidade e ter uma boa interação com o sistema adesivo previamente aplicado, levando a grande parte dos problemas clínicos das restaurações. Conclusão: questionamentos sobre os efeitos da contração de polimerização, ainda não foram completamente elucidados no meio científico, por isso algumas técnicas como a escolha de fotopolimerizadores a LED, manutenção da fase pré gel, manutenção do Fator C e técnica de inserção incremental, podem ser usadas para minimizar os efeitos dessa contração nas restaurações feitas com resina, afim de reduzir insucessos como, sensibilidade pós operatória, infiltração marginal e riscos de agressão pulpar levando a uma maior longevidade dos procedimentos restauradores com materiais resinosos. (AU)

Introduction: a complication inherent in all composite resins is the stress generated by the polymerization contraction. The present composite resins, after polymerization, lose between 2% and 3% of their entire volume. This loss can lead to strongly compromising micro and macroscopic changes. Objective: to address the importance of using technical and clinical maneuvers, which aim to reduce polymerization shrinkage of composite resins, reducing its effects in the cavity, in order to have a restorative procedure with high clinical success rate and good patient acceptance. Material and Methods: a review of the literature through a literature search in the following search online databases was performed: PubMed/MEDLINE, LILACS, BBO and SCIENCE DIRECT, through the screening of relevant articles published between 2000 to 2015. Results: comparing both activation of composites, the dental composites have a lower flow and higher stress of contraction compared to composites with chemical activation, this is the due to photoactivation that stands out for being a quick reaction when compared to other methods, not providing time for the resin to settle in well and have a good interaction with the previously applied adhesive system, leading to much of the clinical problems of restorations. Conclusion: questions about the effects of polymerization shrinkage have not been fully elucidated in the scientific community, so some techniques such as the choice of curing lights to LED, the pre gel phase maintenance, maintenance of Factor C and incremental insertion technique can It is used to minimize the effects of this contraction in restorations made with resin in order to reduce failures as post-operative sensitivity, microleakage and pulp assault risks leading to increased longevity of restorative procedures with resinous materials. (AU)

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