Effectiveness of ultrasonic activation associated to glycolic acid on smear layer removal, dentin structure and bond strength to root dentin

This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.

Pinos de fibra de vidro anatômicos: aspectos adesivos e mecânicos: revisão de literatura / Anatomic fiber posts: bonding and mechanical aspects: literature review

O objetivo desse estudo foi realizar uma revisão de literatura sobre a resistência de união de pinos de fibra de vidro anatômicos (PFVA) quando comparados a pinos de fibra de vidro convencionais (PFVC). Foi realizada busca por artigos na base eletrônicas de dados (PubMed/ Medline, Bireme e Scielo) entre os anos 2000 e 2019, utilizando as palavras chave: pinos (posts), pinos de fibra (fiber posts), resistência de união (bond strength) e retenção (retention). Após isso, os resumos dos estudos foram selecionados de acordo com o tema proposto, baixados e lidos para inserir no trabalho somente os pontos principais de cada trabalho e, assim, formular a revisão de literatura com informações atuais. PFVA apresentam maior resistência de união quando comparados a pinos de PFVC, principalmente pela diminuição da linha de cimentação, que representa o ponto mais fraco da adesão. Diante disso é indicado o uso de PFVA na prática clínica, como uma opção de restauração segura, uma vez que a distribuição das tensões será mais uniforme, evitando a fratura de estruturas fragilizadas, que podem resultar na perda do elemento dentário(AU)

The aim of this study was to perform a literature review on the bond strength of anatomical fiber posts (PFVA) when compared to conventional fiber posts (PFVC). A search for articles was performed in the electronic database (PubMed / Medline, Bireme and Scielo) between the years 2000 and 2019, using as keywords: posts, fiber posts, bond strength and retention. After that, the study abstracts were selected according to the proposed theme, downloaded and read to insert in the study only the main points of each article and, thus, form the literature review with current information. PFVA presents greater bond strength when compared to PFVC, mainly due to the reduction of the cementation line, which represents the weakest bond point. Therefore, the use of PFVA in clinical practice is indicated, as a safe restoration option, since the stress distribution will be more uniform, avoiding the fracture of fragile structures, which can result in the loss of the dental elemento(AU)

Efeito do hipoclorito de sódio na retenção de pinos de fibra de vidro: revisão de literatura / Effect of sodium hypochlorite on fiber posts retention: literature review

O objetivo desse trabalho foi realizar uma revisão de literatura sobre o efeito do hipoclorito de sódio na retenção de pinos de fibra de vidro. Uma busca por artigos foi feita em bases eletrônicas de dados (Pubmed, Bireme e Scielo). Os resumos foram selecionados de acordo com o tema proposto, baixados e lidos para inserir no trabalho somente os pontos principais de cada trabalho e, assim, formular a revisão de literatura com informações atuais sobre o assunto proposto. A discussão foi realizada para compreender os resultados e chegar a considerações finais da revisão fazendo uma conexão com a prática clínica. As conclusões foram baseadas na hipótese de que o hipoclorito de sódio tem efeito negativo na retenção de pinos de fibra de vidro. A presente revisão de literatura mostrou, a partir dos achados dos estudos, que o uso do hipoclorito de sódio pode interferir na retenção de pinos de fibra de vidro ao canal radicular, principalmente quando a irrigação final com EDTA 17% não é realizada(AU)

The objective of this work was to perform a literature review on the effect of sodium hypochlorite on fiber posts retention. A search for articles was done in electronic databases (Pubmed, Bireme and Scielo). The abstracts were selected according to the proposed theme, downloaded and read to insert in the work only the main points of each article and, thus, to formulate the literature review with current information on the proposed subject. The discussion was conducted to understand the results and come to the final considerations of the review by making a connection with clinical practice. The conclusions were based on the hypothesis that sodium hypochlorite has a negative effect on fiber posts retention. The present literature review showed, from the study findings, that the use of sodium hypochlorite can interfere on fiber posts retention to the root canal, especially when the 17% EDTA final irrigation is not performed(AU)

Terapia fotodinâmica na endodontia: revisão de literatura / Photodynamic therapy in endodontics: literature review

A terapia endodôntica busca prevenir e quando necessário eliminar infecções endodônticas. A persistência de microrganismos ao preparo químico mecânico ou a medicação intracanal é considerada a principal causa dos insucessos do tratamento endodôntico. Sendo nestes casos o Enterococcus faecalis o microrganismo mais comumente encontrado. A terapia fotodinâmica (PDT) desponta desta maneira como uma promissora terapia coadjuvante ao tratamento endodôntico convencional para eliminar estes microrganismos persistentes. Esta terapia consiste na associação de uma fonte de luz específica a um fotossensibilizador na presença de oxigênio, produzindo assim espécies citotóxicas aos microrganismos. Assim, o presente artigo tem como objetivo realizar uma revisão de literatura sobre o uso da terapia fotodinâmica na endodontia, a qual demonstra-se efetiva como auxiliar durante o preparo do canal radicular(AU)

Endodontic therapy seeks to prevent and when necessary to eliminate endodontic infections. The persistence of microorganisms to the mechanical chemical preparation or the intracanal medication is considered the main cause of the failures of the endodontic treatment. In these cases Enterococcus faecalis is the most commonly found microorganism. Photodynamic therapy (PDT) emerges as a promising adjuvant therapy to conventional endodontic treatment to eliminate these persistent microorganisms. This therapy consists in the association of a specific light source with a photosensitizer in the presence of oxygen, producing cytotoxic species to the microorganisms. Thus, the present article aims at a review of the literature on the use of photodynamic therapy in endodontics, a test that is shown to assist in the preparation of the root canal(AU)

Manejo endodôntico de dentes reimplantados: revisão de literatura / Endodontical management of replanted teeth: literature review

O reimplante dentário destaca-se como um procedimento conservador, sendo a conduta não-protética que pode ser realizada em casos de avulsão, evitando sequelas estéticas, funcionais e psicológicas junto ao paciente. Para controlar os processos reabsortivos que se desencadeiam devido a lesão no ligamento periodontal, o tratamento endodôntico se faz necessário. Objetivo: apresentar uma revisão de literatura sobre o manejo endodôntico de dentes reimplantados, elucidando os aspectos clínicos, radiográficos e fisiológicos envolvidos no processo e, também, confeccionar um guia de consulta para prática clínica. Conclusão: O reimplante dentário auxilia no aspecto psicológico decorrente da perda dentária, sendo a endodontia uma etapa fundamental no processo. Ao final do tratamento endodôntico de um dente re-implantado, com uso da medicação intracanal adeaquada, a saber hidróxido de cálcio, espera-se um dente clinicamente assintomático e radiograficamente ausência de sinais de reabsorção e lesão apical. Contudo, o acompanhamento clínico e radiográfico do paciente deve ser feito por pelo menos cinco anos(AU)

Dental reimplantation stands out as a conservative procedure, being the non-prosthetic conduct that can be performed in cases of avulsion, avoiding aesthetic, functional and psychological sequelae with the patient. In order to control the resorptive processes that are triggered due to periodontal ligament damage, endodontic treatment is necessary. Objective: to present a review of the literature on the endodontic management of re-implanted teeth, elucidating the clinical, radiographic and physiological aspects involved in the process and also to make a reference guide for clinical practice. Conclusion: Dental reimplantation assists in the psychological aspect resulting from tooth loss, with endodontics being a fundamental step in the process. At the end of the endodontic treatment of a re-implanted tooth, with the use of the intracanal adequate medication, namely calcium hydroxide, a clinically asymptomatic tooth is expected and radiographically no signs of resorption and apical lesion. However, clinical and radiographic monitoring of the patient should be done for at least five years(AU)

Reabilitação estética com laminados cerâmicos ­ relato de caso / Aesthetic rehabilitation with ceramic veneer ­ case report

A demanda por tratamentos restauradores estéticos tem aumentado consideravelmente nos consultórios odontológicos devido ao maior conhecimento por parte dos pacientes. Os laminados cerâmicos de dissilicato de lítio são excelentes opções de tratamento para realizar reabilitações estéticas devido às propriedades estéticas e de resistência do material. Este relato de caso tem como objetivo descrever as etapas envolvidas no protocolo clínico para realizar um tratamento restaurador com laminados cerâmicos ultrafinos.

The demand for aesthetic restorative treatments has increased considerably in dental offices due to increased knowledge on the part of patients. The lithium disilicate laminated ceramics are excellent options to restore dental aesthetics due to their aesthetic properties combined and resistance. This clinical report aims to describe the steps of the clinical protocol of a restorative treatment with ultra-thin ceramic laminates.

Reabilitação estética com laminados cerâmicos: relato de caso / Aesthetic rehabilitation with ceramic veneer: case report

A demanda por tratamentos restauradores estéticos tem aumentado consideravelmente nos consultórios odontológicos devido ao maior conhecimento por parte dos pacientes. Os laminados cerâmicos de dissilicato de lítio são excelentes opções de tratamento para realizar reabilitações estéticas devido às propriedades estéticas e de resistência do material. Este relato de caso tem como objetivo descrever as etapas envolvidas no protocolo clínico para realizar um tratamento restaurador com laminados cerâmicos ultrafinos (AU).

The demand for aesthetic restorative treatments has increased considerably in dental offices due to increased knowledge on the part of patients. The lithium disilicate laminated ceramics are excellent options to restore dental aesthetics due to their aesthetic properties combined and resistance. This clinical report aims to describe the steps of the clinical protocol of a restorative treatment with ultra-thin ceramic laminates (AU).

Does immediate dentin sealing influence the polymerization of impression materials?

OBJECTIVES: The objective of the following study is to evaluate the interaction between the resin materials used in immediate dentin sealing (IDS) techniques and impression materials with two different techniques to eliminate the oxygen-inhibition layer. MATERIALS AND METHODS: The occlusal dentin surface of 35 human molars was exposed. The teeth were used in two Groups: Group 1 - Impression with Express XT; Group 2 - Impression with Impregum. Groups 1 and 2 were divided into 14 subgroups: Groups 1a and 2a - Control groups; 1b and 2b - IDS with Clearfil SE Bond (CSE); 1c and 2c - IDS with CSE + additional polymerization with glycerin jelly; 1d and 2d - IDS with CSE + alcohol; 1e and 2e - IDS with CSE and Protect Liner F (PLF); 1f and 2f - IDS with CSE and PLF + additional polymerization with glycerin jelly; and 1g and 2g - IDS with CSE and PLF + alcohol. Five teeth were used in each experimental group, and the tooth surface was photographed using a digital camera. RESULTS: Small quantity of unpolymerized impression material remained attached to the CSE or to the PLF in Groups 1b and 1e. Groups 1c and 1d prevented the interaction. Small quantity of polymerized impression material remained attached to the CSE or to the PLF for Groups 2b and 2e. The same interaction was observed for Groups 2c and 2d. For Groups 2c and 2f, no interactions were observed. CONCLUSION: Resin materials interacted with impression materials. The application of glycerin jelly and alcohol prevented the interaction of CSE with Express XT and PLF with Impregum; however, these treatments were not completely effective in preventing the interaction of CSE with Impregum and PLF with Express XT.

Influence of resin cements on cuspal deflection and fracture load of endodontically-treated teeth restored with composite inlays.

OBJECTIVES: To evaluate the influence of resin cements on cuspal deflection, fracture load and failure mode of endodontically-treated teeth restored with composite resin inlays. MATERIALS AND METHODS: Forty maxillary premolars were randomly divided into four groups: G1 (sound teeth, control), G2 (RelyX ARC), G3 (RelyX Unicem) and G4 (Maxcem Elite). The teeth from groups 2, 3 and 4 received mesial-occlusal-distal preparations and endodontic treatments. Impressions were taken with vinyl polysiloxane and poured using type IV die stone. Inlays with Z250 composite resin were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal surface and the cuspal deflection was measured using a micrometer. The specimens were then subjected to an axial load until failure occurred. The resulting failure mode was analyzed. RESULTS: The means for cuspal deflection (µm) and fracture load (N) followed by the same letter represent no statistically significant difference based on ANOVA and Tukey's test (p < 0.05). Cuspal deflection: G1 = 4.7 (± 1.7)(a), G2 = 12.0 (± 8.9)(a), G3 = 39.0 (± 27.0)(b) and G4 = 56.8 (± 18.2)(b). Fracture load: G1 = 1982 (± 893)(a), G2 = 690.9 (± 225.5)(b), G3 = 679 (± 193.6)(b) and G4 = 465.5 (± 121.6)(b). G1 presented cusp fractures only at the cement-enamel junction (CEJ). There was a high frequency of cusp fractures below the CEJ in G2, G3 and G4. CONCLUSIONS: Composite resin inlays luted with resin cements do not recover the strength of sound teeth. However, teeth restored with composite resin inlays and luted with RelyX ARC can withstand mechanical fatigue longer before failure occurs than those luted with RelyX Unicem and Maxcem Elite.

Influence of restorative techniques on fracture load of endodontically treated premolars.

UNLABELLED: OBJECTIVE. This study evaluated the influence of restorative techniques on the fracture load and fracture mode of endodontically treated premolars with MOD cavities. MATERIALS AND METHODS: Sixty maxillary premolars were divided into groups: G1 - sound teeth; G2 - direct technique using Four Season; G3 - Adoro inlays; G4 - Adoro onlays; G5 - Empress inlays; G6 - Empress onlays. The specimens were submitted to compressive axial loading until failure. The fracture mode was analyzed. RESULTS. According to ANOVA and Tukey's test (α=0.05), the sound teeth (1370.61 N) showed the highest fracture load mean, which did not differ statistically from IPS Empress onlays (1304.21 N). Intermediate values were obtained for IPS Empress inlays (918.76 N), Adoro onlays (861.15 N), Adoro inlays (792.71 N) which did not differ statistically among them. The lowest fracture load was obtained for direct restorations with Four Seasons (696.08 N), which did not differ statistically from the Adoro inlays. CONCLUSIONS. The ceramic restorations provided higher fracture load and more incidences of catastrophic fractures. Cuspal coverage increased teeth fracture load. The results were similar for direct and indirect inlays with composite resin.

Accuracy of the second pour casts using dual-arch trays.

OBJECTIVE: To compare, in vitro, the accuracy between dental stone casts obtained from the first and the second pour using metallic (Smart) and plastic (Triple Tray) dual-arch trays. MATERIAL AND METHODS: The impressions were taken using Flexitime® vinyl polysiloxane from a typodont model with a mandibular right first molar prepared for a full crown. Ten impressions were made with each tray and poured using type IV die stone. After 1 hour, the casts were removed from the impressions and, 1-hour later, second pours were completed. The mesio-distal and the buccal-lingual widths at the gingival margin of the prepared tooth on the cast were measured in a perfil projector. The results were submitted to Student's t-test (α=0.05) using SPSS version 10.0. RESULTS: There was a statistically significant difference between the first and second pours using the plastic tray in the mesio-distal width. CONCLUSION: It could be suggested that a repeated pour is more accurate using a metallic tray.

Effect of conditioner on microtensile bond strength of self-adhesive resin cements to dentin.

OBJECTIVE: Evaluate, in vitro, the microtensile bond strength (µTBS) of RelyX ARC conventional resin cement and RelyX Unicem and Maxcem self-adhesive resin cements to dentin, and the influence of polyacrylic acid pretreatment on the µTBS. MATERIAL AND METHODS: Flat dentin surfaces were obtained in 15 third molars which were randomly divided into 5 groups: Group 1 - RelyX ARC (control); Group 2 - RelyX Unicem; Group 3 - Maxcem Elite; Group 4 - 22.5% polyacrylic acid and RelyX Unicem; Group 5 - 22.5% polyacrylic acid and Maxcem Elite. A block of composite resin was built over the resin cements. The samples were sectioned to obtain beams, and 20 specimens for each group were submitted to µTBS on a universal testing machine. Failure modes were analyzed by scanning electron microscopy. RESULTS: According to ANOVA and Tukey test, the highest µTBS mean (MPa) was obtained with RelyX ARC (21.38), which did not differ statistically from Maxcem Elite with polyacrylic acid pretreatment (19.22) and RelyX Unicem with polyacrylic acid pretreatment (17.75) (p>0.05). The latter two groups did not differ statistically from RelyX Unicem (16.98) (p>0.05). The lowest mean was obtained for Maxcem Elite (6.43), which differed statistically from the other groups (p<0.05). All failures were adhesive for Maxcem Elite without polyacrylic acid pretreatment, and mixed failures were predominant in the other groups. CONCLUSIONS: RelyX ARC achieved higher µTBS to dentin in comparison to the self-adhesive resin cements. Polyacrylic acid pretreatment was effective in improving the µTBS of Maxcem Elite, but did not influence the µTBS for RelyX Unicem.

Effect of the Nd:YAG and the Er:YAG laser on the adhesive-dentin interface: a scanning electron microscopy study.

OBJECTIVE: This study analyzed the adhesive-dentin interface when Nd:YAG and Er:YAG lasers were applied to dentin. BACKGROUND DATA: Lasers applied to dentin cause morphological changes of this tissue. Because adhesive systems bond to dentin through the hybrid layer, it is important to investigate the adhesive-dentin interface when dentin is irradiated with lasers. METHODS: The occlusal dentin of 12 human molars was exposed and polished with 400 and 600 grit silicon carbide abrasive paper. Teeth were randomly divided into six groups: Group 1, adhesive system Adper Single Bond 2 (SB); Group 2, adhesive system Clearfil SE Bond (CSB); Group 3, Nd:YAG laser (60 mJ, 15 Hz, 0.9 W) and SB; Group 4, Nd:YAG laser (60 mJ, 15 Hz, 0.9 W) and CSB; Group 5, Er:YAG (200 mJ, 4 Hz, 0.8 W) and SB; Group 6, Er:YAG (200 mJ, 4 Hz, 0.8 W) and CSB. Blocks of composite resin were built upon the adhesive system. Tooth-resin sets were cut in a mesio-distal direction, resulting in four samples for each group. Surfaces were polished until 1200 grit silicon carbide abrasive paper, followed by diamond pastes. Samples were demineralized, deproteinized, dried, metalized, and evaluated by scanning electron microscopy. RESULTS: SB formed a thicker hybrid layer, with resin tags longer than CSB. Nd:YAG laser application on the dentin surface, prior to the adhesive procedures, resulted in a thinner hybrid layer with fewer resin tags. Er:YAG laser application on the dentin surface, prior to the adhesive procedures, did not allow the formation of a hybrid layer but formed resin tags. CONCLUSION: Nd:YAG and Er:YAG laser changed the adhesive-dentin interface.