Bond strength and internal adaptation of customized glass fiber posts using different bulk-fill flow resins.

Background: This study aimed to evaluate the bond strength and internal adaptation of customized glass fiber posts using Bulk Fill flowable composite resins (BF) and conventional composite resin. Material and Methods: Fifty bovine teeth were randomly divided (n=10) according to the following groups: G1 (control): glass fiber posts were adapted to the root canal and luted with Rely-X ARC cement (3M® ESPE); G2: fiber posts smaller than the root canal diameter were customized using Filtek™ Z350 XT (3M® ESPE) conventional composite resin, and luted similarly to Group 1. G3: posts were customized with Tetric N-Ceram Bulk Fill composite resin (Ivoclar Vivadent AG), G4: posts were customized with Filtek™ Bulk Fill Flow (3M® ESPE), and G5: posts were customized with SureFil SDRTM flow (DENTSPLY), respectively. The specimens were submitted to push-out testing and internal adaptation evaluation using optical microscopy. Push-out (MPa) and internal adaptation (%) data were subjected to ANOVA and Tukey's post-hoc tests (p = 5%). Results: No statistically significant differences were found in both evaluations (p<0.05). Conclusions: Customized glass fiber posts using different bulk fill flowable composites did not affect the post bond-strength and internal adaptation, presenting similar results to customized glass fiber posts using conventional composite or posts with no previous customization. Key words:Dental pulp, composite resins, fiber posts, glass fiber post.

Repair Techniques in CAD/CAM System Ceramics: a Literature Review / Técnicas de Reparo em Cerâmicas do Sistema CAD/CAM; uma Revisão de Literatura

Abstract Currently, CAD / CAM systems have been increasingly used in Dentistry, however due to the characteristic of the technique, since it is milled from a ceramic block, some flaws, such as fractures, become a challenge after the piece is cemented. To avoid the complete replacement of the part, the technique through intraoral repair of the fractured region is ideal for these cases. There are several protocols for this technique, this study aims to review the literature regarding the techniques and protocols for ceramic repair of the CAD / CAM system. A literature review was carried out on the Pubmed database using the terms Ceramic repair, Adhesive and Composite resin searching for studies published in the period from 2000 to 2020. 104 articles were found, after reading 32 articles were selected because they presented a greater correlation with the present study. There was unanimity among the authors about the importance of a surface treatment on the ceramic to be repaired, 70% of them still indicated the roughness with drills and conditioning with hydrofluoric acid due to the ease of the technique and good result. The combination of several surface treatments in the same region to be repaired produces better tensile strength. The use of the silane agent in a separate step presents better bonding strength results when compared to the universal type adhesive system with silane incorporated in the formula. (AU)

Resumo Atualmente os sistemas CAD/CAM tem sido cada vez mais utilizados na Odontologia, porém devido a característica da técnica, já que é fresada a partir de um bloco cerâmico, algumas falhas, como fraturas, se tornam um desafio após a peça ser cimentada. Para evitar a completa substituição da peça a técnica através de reparo intraoral da região fraturada é ideal para esses casos. Existem diversos protocolos para esta técnica, este estudo tem por objetivo uma revisão de literatura quanto às técnicas e protocolos de reparo em cerâmica do sistema CAD/CAM. Foi realizada uma revisão de literatura no indexador Pubmed database utilizando os termos Ceramic repair, Adhesive e Composite resin buscando estudos publicados no período de 2000 a 2020. Foram encontrados 104 artigos, após leitura 32 artigos foram selecionados pois apresentavam maior correlação com o presente estudo. Foi unanimidade entre os autores acerca da importância de um tratamento de superfície na cerâmica a ser reparada, 70% deles ainda indicaram a asperização com brocas e condicionamento com ácido fluorídrico pela facilidade da técnica e bom resultado. A associação de vários tratamentos de superfície na mesma região a ser reparada produz melhor resistência a tração. O uso do agente silano em etapa separada apresenta melhores resultados de resistência de união quando comparado ao sistema adesivo do tipo universal com silano incorporado na fórmula. (AU)

The impact of different surface treatments on the shear bond strength of orthodontic metal brackets applied to different CAD/CAM composites.

BACKGROUND: To investigate the shear bond strength (SBS) of orthodontic metal brackets applied to different CAD/CAM composites treated with different surface treatments. MATERIAL AND METHODS: Specimens of two CAD/CAM composites were obtained of Lava Ultimate (LU; n=60) and Brilliant Crios (BC; n=60) which were randomly separated into six subgroups (n=10) according to the surface treatment: control (CTL); sandblasting (SB); sandblasting and silane (SBSL); hydrofluoric acid (HF); hydrofluoric acid and silane (HFSL); and Monobond Etch&Prime (MEP). The mandibular central incisor metal brackets were bonded with a light-cure adhesive. The SBS data were analyzed using the two-way analysis of variance and Turkey's test, while the adhesive remnant index (ARI) by the Kruskal-Wallis, all the significance was set at 5%. RESULTS: A higher SBS was found for BC in comparison with LU (p< 0.05). All the surface treatments increased the SBS in comparison with CTL (p< 0.0001). Treatment with HF, SBSL and HFSL (p> 0.05) showed a higher SBS, which was followed by MEP and SB (p> 0.05), all in comparison with CTL (p< 0.0001). For ARI, a significant effect was detected only for the surface treatment (p< 0.01), and not for CAD/CAM resin (p> 0.05). Significant differences were detected between CTL to HF, and HF to MEP, as well. CONCLUSIONS: The SBS is highly affected by the surface treatment and also by the CAD/CAM composite. The surface treatment improves the SBS and should be encouraged when orthodontic brackets are bonded to CAD/CAM composites. Key words:CAD/CAM composite resin, brackets, shear bond strength, surface treatment, bonding.

Retrospective Analysis of the Prevalence of Teeth Endodontically Treated from Radiographs of Individuals from the Midwest Region of Brazil / Análise Retrospectiva da Prevalência de Dentes Tratados Endodônticamente a Partir de Radiografia de Indivíduos da Região do Centro Oeste no Brasil

Endodontic treatment is common in dentistry and for a correct diagnosis it is necessary to observe clinical and radiographic signs, taking into account pulp and periapical changes in the element to be treated. Studying this frequency can contribute to the literature, elucidating whether the greatest number of cases is occurring in young or elderly patients, women or men, anterior or posterior teeth. The objective of this study was to analyze the prevalence of endodontically treated teeth, through 900 panoramic radiographs. A cross-sectional study was carried out evaluating the prevalence of teeth treated endodontically from a sample of 900 panoramic radiographs, corresponding to exams performed in 2020, in a radiological clinic located in central west Brazil. The sample consisted of 540 (60%) female subjects and 360 (40%) male subjects, aged between 18 and 88 years old, being more prevalent for Individuals <31 years old with (34.9%) Sample. The prevalence of endodontically treated teeth was analyzed, the results showed 1,236 teeth in this condition, individually analyzing the upper right central incisor was the most frequent 9.22%, while for group analysis the upper teeth were 7.06%. Therefore, there was a higher prevalence of teeth treated endodontically in the maxilla, the tooth with the highest treatment index, the right upper central incisor. Women were more affected and it was observed that with increasing age, the number of teeth treated endodontically also increases. (AU)

O tratamento endodôntico é frequente na odontologia e para um correto diagnóstico é necessário observar sinais clínicos e radiográficos, levando em consideração as alterações pulpares e periapicais no elemento à ser tratado. Estudar essa frequência pode colaborar com a literatura, elucidando se o maior número de casos está ocorrendo em pacientes jovens ou idosos,mulheres ou homens, dentes anteriores ou posteriores O objetivo desse presente estudo foi analisar a prevalência de dentes tratados endodônticamente, por meio de 900 radiografias panorâmicas. Foi realizado um estudo transversal avaliando prevalência de dentes tratados endodônticamente a partir de uma amostra de 900 radiografias panorâmicas, correspondentes a exames realizados em 2020, em uma clínica radiológica situada no centro oeste do Brasil. A amostra foi constituída por 540 (60%) Indivíduos do gênero feminino e 360 (40%) do masculino, com idade entre 18 e 88 anos de idade, sendo mais prevalente para Indivíduos <31 anos de idade com (34,9%) da amostra. Foi analisada a prevalência de dentes tratados endodônticamente, os resultados mostraram 1.236 dentes nesta condição, analisando individualmente o incisivo central superiores direito foi o mais frequente 9,22%, enquanto para análise de dentes por grupos foram os dentes anteriores superiores 7,06%. Portanto, houve uma maior prevalência de dentes tratados endodônticamente em maxila, o dente com maior índice de tratamento o incisivo central superior direito. Mulheres foram mais acometidas e observou-se que com o aumento da idade, aumenta-se também o número de dentes tratados endodônticamente. (AU)

Evaluation of the Light Intensity Emitted by the Light-curing Devices of a Dental School Clinic in the North of Brazil: a Pilot Study / Avaliação da Intensidade de Luz Emitida Pelos Fotopolimerizadores de uma Clínica-Escola da Região Norte do Brasil: um Estudo-Piloto

Photoactivated composite resins are among the most widespread restorative materials in dentistry, particularly in cosmetic dentistry. To obtain the best properties of the material, the resins must have their polymerization reaction initiated by means of the light-curing device, which activates the photoinitiators present in the composites. For this process to occur in the desired way, it is essential that the light-curing device emits light at the intensity necessary to properly activate the photoinitiators. Thus, a pilot study was carried out to assess the light intensity emitted by the light-curing devices used in a school clinic. To assess the light intensity emitted by the devices, a radiometer was used. Twentyfour light-curing devices were evaluated, 13 Optilight Max devices, 8 Optilight LD MAX 440 devices, 3 Emitter C. devices. All the devices had an emitted light below 400 mW / cm² and 67% of the devices had intensity above 300 mW/cm². The average light emission values of the light-curing devices were Optilight Max 334mW/cm², Emitter C 275mW/cm², Optilight LD MAX 440 296mW/cm². It was concluded that no light-curing device emitted light at the recommended intensity (400 mW/cm²), two thirds of the devices emitted light in intensity above the minimum required for photopolymerization of composite resin increments of up to 2mm and one third emitted light in intensity below the required minimum. There was no difference among the light-curing device models tested in this study. (AU)

As resinas compostas fotoativadas estão entre os materiais restauradores mais difundidos em odontologia, particularmente na odontologia estética. Para obtenção das melhores propriedades do material, as resinas precisam ter sua reação de polimerização iniciada por meio do fotopolimerizador, que ativa os fotoiniciadores presentes nos compósitos. Para que esse processo ocorra da forma desejada, é fundamental que o fotopolimerizador emita a luz na intensidade necessária para ativar adequadamente os fotoiniciadores. Assim, foi realizado um estudo piloto para avaliadar a intensidade da luz emitida pelo fotopolimerizadores utilizados em uma clínica-escola. Para avaliar a intensidade da luz emitida pelos dispositivos, foi utilizado um radiômetro. Vinte e quatro fotopolimerizadores foram avaliados, 13 aparelhos Optilight Max, 8 aparelhos Optilight LD MAX 440, 3 aparelhos Emitter C. Todos os dispositivos tiveram a luz emitida em intensidade inferior a 400 mW/ cm² e 67% dos dispositivos apresentaram intensidade acima de 300 mW/cm². As médias de valores de emissão de luz dos fotopolimerizadores foram, Optilight Max 334mW/cm², Emitter C 275mW/cm², Optilight LD MAX 440 296mW/cm²Concluiu-se que nenhum fotopolimerizador emitiu luz na intensidade recomendada (400 mW/cm²), dois terços dos aparelhos emitiram luz em intensidade acima da mínima necessária para fotopolimerização de incrementos de resina composta de até 2mm e um terço emitiu luz em intensidade abaixo da mínima necessária. Não houve diferença entre os modelos de fotopolimerizador testados neste estudo.(AU)

Effects of Brown and Green Propolis on Bond Strength of Fiberglass Posts to Root Canal Dentin.

Introduction: The purpose of this study was to evaluate the effect of brown and green propolis on bond strength of the fiberglass posts to root canal dentin, and to compare it with conventional endodontic irrigants. Methods and Materials: Sixty bovine teeth were selected, decoronated and randomly distributed into six groups (n=10), according to the irrigation solution: 0.9% saline solution (Control); 2% chlorhexidine (CHX); 5% malic acid (MA); 0.5% ethanolic extract of brown propolis (BP); 0.25% ethanolic extract of green propolis (GP); 2.5% sodium hypochlorite (NaOCl). After root canal treatment, fiber posts were cemented into prepared root canals with a self-adhesive resin cement. The roots were cross-sectioned to obtain two discs from each third and submitted to the micro push-out test. Failure patterns were evaluated under optical microscopy. The influence of irrigants agents was analyzed using one-way ANOVA followed by Games-Howell's test (α=0.05). Failure modes were analyzed using Fischer's exact test (α=0.05). Results: There were statistically significant differences among the groups (P<0.05). The control, NaOCl and BP groups showed the highest bond strength with no statistically significant difference between them (P>0.05). Adhesive failure type was the predominant in all groups. Conclusion: Based on this in vitro study, the use of 0.5% brown propolis did not influence the bond strength of fiberglass posts to root canal dentin, while the use of 0.25% green propolis did affect it negatively.

Restauração de dente posterior com resina Bulk Fill: relato de caso clínico / Posterior tooth restoration with a bulk fill composite: a case report

Objetivo: Demonstrar o uso da resina Bulk Fill como material de preenchimento em restaurações posteriores. Material e métodos: Paciente do sexo feminino, 28 anos, compareceu a clínica privada relatando incômodo nos dentes da região postero inferior esquerda. Após realização dos exames clínicos e radiográficos foi observada que havia restauração ocluso distal (OD) em resina composta com fratura da margem estendendo para face proximal e ausência de cárie no dente 35. Presença de cárie secundária sob a restauração de amálgama mesio ocluso distal (MOD) no dente 36 e restauração satisfatória em resina composta no dente 37. Como plano de tratamento foi proposta a substituição das restaurações dos dentes 35 e 36. Resultados: As restaurações dos dentes 35 e 36 foram removidas e após limpeza da cavidade, foi realizado tratamento dentinário com sistema adesivo autocondicionante e adaptação de matriz metálica. Inicialmente, o dente 35 foi restaurado com resina micro-híbrida e em seguida a restauração do dente 36 com a inserção da resina Bulk Fill com auxílio de um dispensador. A ponta do compule foi posicionada na parte mais profunda da cavidade e a resina injetada até o preenchimento de 4 mm. A restauração foi finalizada com incrementos de 2 mm da resina micro-híbrida na oclusal e polida após o período de 24 horas. Conclusões: A resina Bulk Fill pode ser utilizada como material de preenchimento em restaurações de dentes posteriores, permitindo a confecção de restaurações com maior praticidade e menor tempo clínico.

Objective: To demonstrate the use of a Bulk Fill composite as a fill material in posterior restoration. Material and Methods: Female patient, 28 years old, was presented to a private clinic with complaints of her lower left teeth region. Clinical and radiographic examination revealed: (i) an occlusal-distal composite resin restoration on tooth 35 (lower left second premolar) with fractured margin extending to the proximal face, but no signs of carie; (ii) presence of secondary caries under a mesialocclusal- distal (MOD) amalgam restoration on tooth 36 (lower left first molar), and (iii) satisfactory composite resin restoration on tooth 37 (lower left second molar). As a treatment plan it was proposed the replacement of the restoration on teeth 35 and 36. Results: The restoration on the teeth 35 and 36 were removed and after cleaning the cavity, dentin treatment with a self-etching adhesive system and metal matrix adaptation were performed. The tooth 35 was initially restored with a micro-hybrid resin and then restoration of the tooth 36 was carried out using a Bulk fill resin with the aid of a dispenser. The tip of the dispenser was placed in the deepest part of the cavity and the resin injected to a 4-mm filling. The restoration was completed by adding 2-mm increments of micro-hybrid resin on the occlusal face of the tooth, followed by polishing after 24h. Conclusion: Bulk Fill resin can be used as a fill material in posterior tooth restoration, thereby allowing restoration to be made with greater convenience and shorter clinical time.

Resistência de união à microtração de sistemas adesivos "condiciona-e-lava" de dois passos: efeito de diferentes tratamentos da superfície dentinária condicionada / Microtensile bond strength of 2-step etch-and-rinse adhesive systems: Effects of different treatments of etched dentin

Introdução: A evolução dos sistemas adesivos permitiu que os fabricantes desenvolvessem materiais com técnicas cada vez mais simplificadas, porém que, ainda assim, promovessem adequados valores de resistência de união imediata. Sugere-se que alguns tratamentos da superfície dentinária podem favorecer esse processo de adesão. Objetivo: Avaliar os efeitos de diferentes tratamentos, em superfície dentinária plana condicionada, sobre a resistência de união à microtração de sistemas adesivos do tipo "condiciona-e-lava" de dois passos. Material e método: Noventa e seis terceiros molares humanos foram divididos em 12 grupos (n=8), aleatoriamente, de acordo com o sistema adesivo utilizado (GI: Adper Single Bond 2 - 3M ESPE; GII: Prime & Bond 2.1 - Dentsply; GIII: Excite - Ivoclar Vivadent) e o tipo de tratamento do substrato dentinário condicionado (a: água; b: clorexidina + água; c: etanol; d: clorexidina + etanol). Todos os dentes foram restaurados com resina Charisma na cor A2 (Heraeus - Kulzer, Germany) e submetidos a ensaio mecânico de microtração (EMIC DL-2000). O teste estatístico realizado foi ANOVA a um fator, completado com teste de Tukey. Resultado: Os grupos GIIc, GIIIc e GIId apresentaram aumento significativo estatisticamente na resistência de união à microtração imediata. Conclusão: Os diferentes tratamentos da dentina condicionada não afetaram de maneira negativa a resistência de união para todos os sistemas adesivos testados e a utilização da técnica com etanol, associado ou não à clorexidina, parece ser uma interessante abordagem quando associada a sistemas adesivos "condiciona-e-lava" de dois passos.

Introduction: The development of adhesive systems allow manufacturers to develop materials with increasingly simplified techniques, but that still would promote adequate resistance values of immediate union. It is suggested that some treatments of dentin surface can facilitate the process of accession. Objective: To evaluate the effects of different treatments in conditioned flat dentin surface on bond strength to microtensile 2-step etch-and-rinse adhesive systems. Material and method: Ninety-six human third molars were divided into twelve groups (n = 8) randomly according to the used adhesive system (GI: Single Bond 2 - 3M ESPE; GII: Prime & Bond 2.1 - Dentsply; GIII: Excite - Ivoclar Vivadent) and type of treatment of the conditioned dentin (a: water; b: water + chlorhexidine; c: ethanol; d: chlorhexidine + ethanol). All teeth were restored with Charisma color A2 (Heraeus - Kulzer, Germany) and subjected to mechanical testing microtensile (EMIC DL-2000). The statistical test performed was ANOVA 1 factor supplemented with Tukey test. Result: GIIc groups GIIIc and GIId showed statistically significant increase in bond strength to immediate microtensile. Conclusion: The different treatments of dentin did not affect negatively the bond strength for all tested adhesive systems and the use of the technique with ethanol, with or without chlorhexidine, appears to be an interesting approach when combined with 2-step etch-and-rinse adhesive systems.

Simvastatin modulates gingival cytokine and MMP production in a rat model of ligature-induced periodontitis.

PURPOSE: The aim of this study was to evaluate the effect of simvastatin on the synthesis of cytokines TNF-α and IL-10 and metalloproteinase (MMPs) 2 and 9 in a rat model of ligature-induced periodontitis. MATERIALS AND METHODS: Twenty Wistar rats were used, and a cotton ligature was place in a subgingival position encircling the entire cervix of the first molar of the left (ipsilateral) side of the mandible. The right (contralateral) side of the mandible had no ligature placed and was used as control. After the ligature placement, animals were randomly assigned to two experimental groups (n=10): 1) rats with ligature + vehicle (saline; 10 mL/kg; orally) and 2) rats with ligature + simvastatin (25 mg/kg; orally). After 14 days of treatment, the animals were euthanized by anesthetic overdose and the gingival tissue was removed and homogenized in appropriate buffer. MMP-2 and -9 release as well as the IL-10 and TNF-α levels were detected by enzyme-linked immunosorbent assay. Statistical comparison was performed by unpaired Student's t-test, with p<0.05 representing significance. RESULTS: No differences were observed for TNF-α production between the groups (p>0.05). However, IL-10 was upregulated in simvastatin-treated animals (1.8-fold increase) in comparison with the vehicle-treated group (p<0.05). Simvastatin reduced the gingival levels of MMP-9 (64.3%) in comparison with vehicle-treated samples (p<0.05). CONCLUSION: Oral treatment with simvastatin increased the release of IL-10 and reduced the MMP-9 in ligature-induced periodontitis model in rats.

Evaluation of Bond Strength, Marginal Integrity, and Fracture Strength of Bulk- vs Incrementally-filled Restorations.

PURPOSE: This study evaluated the effect of application technique and preparation size on the fracture strength (FS), microtensile bond strength (µTBS) and marginal integrity (MI) of direct resin composite restorations. MATERIALS AND METHODS: Conservative (5 × 2 × 2 mm) or extended (5 × 4 × 2 mm) preparations below the cementoenamel junction were performed in 140 human maxillary premolars (n = 70 per group). After adhesive application (XP Bond), half of each group was restored with the bulk technique (one 4-mm increment of Surefill SDR Flow plus one 1-mm horizontal capping layer of TPH3 [Spectrum TPH3 resin composite]) and half incrementally (TPH3 in three horizontal incremental layers, 1.5 to 2 mm each), all using a metal matrix band. After storage (24 h at 37°C), the proximal surfaces of each tooth were polished with Sof-Lex disks. For FS measurement, 60 restorations were mounted in a universal testing machine and subjected to a compressive axial load applied parallel to the long axis of the tooth, running at a crosshead speed of 0.5 mm/min. For µTBS testing, 40 teeth were longitudinally sectioned to obtain resin-dentin bonded sticks from the cavity floor (bonded area: 0.8 mm2). Specimens were tested in tension at 0.5 mm/min. The external marginal integrity of both proximal surfaces was analyzed using SEM of epoxy resin replicas. The µTBS, marginal integrity, and fracture resistance data were subjected to two-way ANOVA, and Tukey's post-hoc test was used for pair-wise comparisons (a = 0.05). RESULTS: Fracture resistance, microtensile bond strength, and marginal integrity values were not statistically significantly affected by application technique or preparation size (p = 0.71, p = 0.82, and p = 0.77, respectively). CONCLUSIONS: The use of a bulk-fill flowable composite associated with a conventional resin composite as a final capping layer did not jeopardize the fracture strength, bond strength to dentin, or marginal integrity of posterior restorations.

Association between Tooth Loss and Degree of Temporomandibular Disorders: A Comparative Study.

OBJECTIVE: The aim of this study was to evaluate the association between tooth loss and the signs and symptoms of temporomandibular disorders (TMDs). MATERIALS AND METHODS: One hundred fifty patients with an average age of 49.2 (±14.06) years were divided into three groups (n = 50/group) according to the degree of tooth loss: GI (dentate -control), GII (edentulous), GIII (partially dentate). After performing anamnesis and clinical examination, a questionnaire was used, so that the patients could fill in information on signs and symptoms of TMD. After analyzing this information, it was possible to classify the degree of severity of TMD. As age is a confounding variable to the level of TMD, an analysis of covariance (ANCOVA) was used to check for differences in the degree of TMD between groups (covariate = age). A post hoc test (Bonferroni) was performed to compare the groups two by two (5% significance level). RESULTS: The mean level of TMD according to the groups was GI - 1.95; GII - 2.15; GIII - 2.55. There were significant differences between the study groups (p > 0.05). A post hoc test (Bonferroni) confirmed the difference between edentulous patients and the other groups. CONCLUSION: The tooth loss is directly related to the signs and symptoms of TMD. The degree of TMD was significantly higher in edentulous patients.

Effects of alpha-tocopherol on fracture resistance after endodontic treatment, bleaching and restoration.

This study evaluated the effects of 10% alphatocopherol on the fracture resistance of endodontically treated teeth subjected to tooth bleaching with hydrogen peroxide and immediately restored with composite resin. Fifty bovine incisors were selected, including 10 sound teeth that constituted the control group (G1 (C)). The remaining 40 teeth, which were endodontically treated, were divided into four groups (n = 10): G2 (CR), consisting of teeth immediately restored with composite resin; G3 (HP + CR), consisting of teeth subjected to tooth bleaching with 38% hydrogen peroxide and immediately restored with composite resin; G4 (HP + SA + CR), which received treatment similar to that used for G3, but with 10% sodium ascorbate gel applied after the bleaching protocol; and G5 (HP + AT + CR), which was similar to G4 but included 10% alphatocopherol gel as an antioxidant. After 24 h, composite restorations were performed, and teeth were subjected to a fracture resistance test at a speed of 0.5 mm/min in an electromechanical testing machine. The axial force was applied with an angle of incidence of 135° relative to the long axis of the root. Data were subjected to ANOVA and Tukey tests (p = 0.05). G1 exhibited the highest fracture resistance (p < 0.05). No significant differences among the other experimental groups were observed. The 10% sodium ascorbate and 10% alphatocopherol gels did not improve the fracture resistance of endodontically treated teeth subjected to bleaching with 38% hydrogen peroxide.

Effects of alpha-tocopherol on fracture resistance after endodontic treatment, bleaching and restoration

Abstract This study evaluated the effects of 10% alphatocopherol on the fracture resistance of endodontically treated teeth subjected to tooth bleaching with hydrogen peroxide and immediately restored with composite resin. Fifty bovine incisors were selected, including 10 sound teeth that constituted the control group (G1 (C)). The remaining 40 teeth, which were endodontically treated, were divided into four groups (n = 10): G2 (CR), consisting of teeth immediately restored with composite resin; G3 (HP + CR), consisting of teeth subjected to tooth bleaching with 38% hydrogen peroxide and immediately restored with composite resin; G4 (HP + SA + CR), which received treatment similar to that used for G3, but with 10% sodium ascorbate gel applied after the bleaching protocol; and G5 (HP + AT + CR), which was similar to G4 but included 10% alphatocopherol gel as an antioxidant. After 24 h, composite restorations were performed, and teeth were subjected to a fracture resistance test at a speed of 0.5 mm/min in an electromechanical testing machine. The axial force was applied with an angle of incidence of 135° relative to the long axis of the root. Data were subjected to ANOVA and Tukey tests (p = 0.05). G1 exhibited the highest fracture resistance (p < 0.05). No significant differences among the other experimental groups were observed. The 10% sodium ascorbate and 10% alphatocopherol gels did not improve the fracture resistance of endodontically treated teeth subjected to bleaching with 38% hydrogen peroxide.

Comparison of Antimicrobial Activity between Chemical Disinfectants on Contaminated Orthodontic Pliers.

AIM: To compare the antimicrobial activity of the chemical substances--70% isopropyl alcohol, 2% glutaraldehyde (GTA) and 0.25% peracetic acid (PAA) in disinfecting orthodontic pliers contaminated in vitro with Streptococcui mutani, Staphylococci aureui and Candida albicani. MATERIALS AND METHODS: Distal end cutter pliers were divided into five groups: group 1 (negative control--sterilized pliers), group 2 (positive control--sterilized plier, subsequently contaminated), group 3 (disinfected with 70% isopropyl alcohol, friction method), group 4 (disinfected with 2% GTA, immersion method for 30 minutes), group 5 (disinfected with 0.25% peracetic acid (PAA), immersion method for 10 minutes). After the pliers were treated with one disinfectant and submitted to microbiological evaluation (by counting colony forming units), they were submitted to the same cleansing, sterilizing and contaminating processes, and were used in the following groups (crossover and washout study). The two-factor analysis of variance (ANOVA) test, followed by the Tukey test, was used to compare the groups. RESULTS: The results showed that there was no statistically significant difference between the three tested disinfectants. CONCLUSION: Although there were no statistically significant differences between the disinfectants, the chemical agents 2% glutaraldehyde and 0.25% PAA were effective in inhibiting the growth of the three microorganisms tested; however, 70% isopropyl alcohol was unable to completely eliminate S. aureui. CLINICAL SIGNIFICANCE: The chemical substances 2% glutaraldehyde and 0.25% PAA completely eliminated the microorganisms tested.

In vivo Evaluation of Proximal Resin Composite Restorations performed using Three Different Matrix Systems.

OBJECTIVE: The aim of this in vivo study was to radiographically evaluate the proximal contour of composite resin restorations performed using different matrix systems. MATERIALS AND METHODS: Patients with premolars needing class II type resin composite restorations involving the marginal ridge were selected. Thirty premolars were selected and randomly divided into three groups (n = 10 each) to receive restorations using different matrix systems: group 1: metal matrix coupled to a carrier matrix and wood wedge (G1-MMW); group 2: sectioned and precontoured metal matrix and elastic wedge (G2-SME); and group 3: a polyester strip and reflective wedge (G3-PMR). After the restorative procedure, bitewing radiographs were performed and analyzed by three calibrated professionals. The quality of the proximal contact and marginal adaptation of the proximal surfaces was classified as either correct or incorrect (undercontour/overcontour). RESULTS: The Pearson Chi-square statistical test (α = 5%) revealed a statistically difference between frequencies of correct and incorrect restorations (α(2) = 6.787, p < 0.05). The group G2 SME produced a higher frequency of correct proximal contours (90%), while G1-MMW and G3-PMR had a ratio of 40% correct and 60% incorrect contours respectively. CONCLUSION: None of the matrix systems was able to prevent the formation of incorrect proximal contours; however, the sectioned and precontoured metal matrix/elastic wedge configuration provided better results as compared to the other groups.

Effectiveness of Oral Antiseptics on Tooth Biofilm: A Study in vivo.

AIM: To evaluate the effectiveness of five different mouthwashes through measurement of the plaque index. MATERIALS AND METHODS: Fifty subjects took part in this blind study, randomized into blocks of five groups according to the active ingredient of the mouthwash: CHX group (0.12% chlorhexidine gluconate), essential oils (EO) group, cetylpyridinium chloride (CPC) group, Tri group (triclosan) and Hamamelis virginiana (HV) group. All subjects were evaluated for a reduction in the bacterial plaque index at 7, 14 and 21 days. RESULTS: There was a significant reduction in the mean plaque index during the period of evaluation (p < 0.01), and the reduction during the period of evaluation was different between mouthwashes (p < 0.01). The reduction in the plaque index at the end of 21 days was, in decreasing order, CHX > EO > CPC > Tri > HV. CONCLUSION: The reduction in the plaque index during the period of evaluation was different between the types of mouth-wash. The mouthwash containing the active ingredient chlorhexidine was the most effective, followed by the essential oil, cetylpyridinium chloride, triclosan and H. virginiana.

Nd:YAG Laser to obtain Irregularities on the Inner Surface of Porcelain.

AIM: The aim of this study was to evaluate the inner surface of two ceramic systems: IPS Empress II (Ivoclar Vivadent, Germany) and In-Ceram Alumina (Vita Zahnfabrick, Germany) submitted to surface treatments, especially by Nd:YAG laser. MATERIALS AND METHODS: Fifty samples were prepared in pellet form for each ceramic system according to manufacturers' specifications. The samples were stored at room temperature and then be subjected to surface treatment: without treatment (T0) (control), hydrofluoric acid-etched (T1), hydrofluoric acid-etched associated with the airborne particle-abraded (T2); CoJet system (T3), Nd:YAG laser (T4). The data were performed the statistical analysis by ANOVA and Tukey's test (p < 0.001). RESULTS: The group control (T0) of the ceramics, the analysis showed the lowest roughness values; for the System Alumina In-Ceram, treatment with hydrofluoric acid (T1), associated with hydrofluoric acid and airborne particle-abraded (T2) and Nd:YAG laser (T4), had no statistically significant difference, whereas for the IPS Empress System II treatment with hydrofluoric acid (T1) and hydrofluoric acid associated with airborne particle-abraded (T2), had no statistically significant difference between the system and also CoJet (T3) and hydrofluoric acid associated with the airborne particle-abraded (T2). Photomicrographs of scanning electron microscopy showed different characteristics to the treatments for each ceramic system. CONCLUSION: The IPS Empress II had the appearance of favoring the retention when treated with hydrofluoric acid, as well as its association with the airborne particle-abraded. Uncertainty in Alumina, treatment with hydrofluoric acid associated with the airborne particle-abraded and CoJet system and provided a surface with irregularities. With respect to the laser further studies should be performed for parameters that are ideal for your application. CLINICAL RELEVANCE: The ceramic restorations are attractive due of their excellent esthetics and the ability to stay for long periods. However, the retention of ceramic requires further study.

Shear Bond Strength of Orthodontic Brackets Fixed with Remineralizing Adhesive Systems after Simulating One Year of Orthodontic Treatment.

The objective of this study is to assess, in vitro, the shear bond strength of orthodontic brackets fixed with remineralizing adhesive systems submitted to thermomechanical cycling, simulating one year of orthodontic treatment. Sixty-four bovine incisor teeth were randomly divided into 4 experimental groups (n = 16): XT: Transbond XT, QC: Quick Cure, OL: Ortholite Color, and SEP: Transbond Plus Self-Etching Primer. The samples were submitted to thermomechanical cycling simulating one year of orthodontic treatment. Shear bond strength tests were carried out using a universal testing machine with a load cell of 50 KgF at 0.5 mm/minute. The samples were examined with a stereomicroscope and a scanning electron microscope (SEM) in order to analyze enamel surface and Adhesive Remnant Index (ARI). Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) tests showed a significant difference between the studied groups (p < 0.05). Groups XT, QC, and SEP presented the highest values of adhesive resistance and no statistical differences were found between them. The highest frequency of failures between enamel and adhesive was observed in groups XT, QC, and OL. Quick Cure (QC) remineralizing adhesive system presented average adhesive resistance values similar to conventional (XT) and self-etching (SEP) adhesives, while remineralizing system (OL) provided the lowest values of adhesive resistance.

Can Whitening Strips interfere with the Bond Strength of Composite Resins?

AIM: The aim of this study was to investigate in vitro the bond strength of composite resins on enamel previously treated with whitening strips. MATERIALS AND METHODS: A total of 48 bovine incisors were allocated to four experimental groups (n = 12 each): G1 (WSC)- treated with 9.5% hydrogen peroxide whitening strips (3D White Whitestrips® Advanced Vivid/CREST); G2 (WSO)-treated with 10% hydrogen peroxide whitening strips (3D WhiteTM/Oral B); G3 (WG)-treated with 7.5% hydrogen peroxide gel with fluorine, calcium and potassium nitrate (White Class®/FGM); and G4 (C)-control not subjected to bleaching treatment. The specimens were subjected to bleaching over 2 weeks following the manufacturers' instructions. Following the elaboration of the composite resin test specimens, the samples were stored in artificial saliva and subsequently subjected to the micro-shear test using the universal testing machine (EMIC®). The bond strength values were analyzed by one-way ANOVA and Tukey's statistical test (5%). RESULTS: Significant differences were observed among the investigated groups (p < 0.05). The G3-WG exhibited greater values compared with the control group and the groups treated with strips, G1-WSC and G2-WSO. Analysis of the bond interface revealed that a large fraction of the failures occurred at the enamel-resin interface. CONCLUSION: The bond strength decreased following 14 days of treatment with bleaching strips, whereas the whitening gel with 7.5% hydrogen peroxide, calcium and fluorine increased the bond strength.

Semidirect Restorations in Multidisciplinary Treatment: Viable Option for Children and Teenagers.

Due to the esthetic necessity required nowadays, the multidisciplinary treatment became a fundamental step in the restoration success. When the patient exhibits dental agenesis of one or more elements, he can show difficulty in social interactions. The age of the patient is a limiting factor to esthetic procedures, however, it should be evaluated as a real indicative with each case. The utilization of semi-direct restorations is a viable option due the cost, esthetic and improvement of physical and mechanical properties. The purpose of this paper is to present a case detailing the confection and cementation of anterior semi-direct restorations aimed at an anatomic reestablishment associated with integrated treatment with periodontics and orthodontics.