Multidisciplinary management of a tooth with severe root dilaceration and enamel hypoplasia: a case report.

Dental trauma in primary teeth can cause irreversible changes in the development of permanent tooth germs, including enamel hypoplasia, crown dilaceration, and root dilaceration. This article discusses multidisciplinary treatment of enamel hypoplasia and root dilaceration in the maxillary left central incisor of an 11-year-old girl. A 10-year follow-up is reported to demonstrate the long-term clinical outcomes. At the initial presentation, the patient's mother reported that the child had an accident at the age of 2 years, resulting in intrusive luxation of the primary maxillary left central incisor. After the accident, the patient was monitored for eruption of the permanent successor tooth, and different approaches were proposed during each period of the patient's development on the basis of the clinical diagnosis of root dilaceration and enamel hypoplasia. The crown was restored with composite resin, and the root defect was restored with resin-modified glass ionomer cement. After 10 years, the clinical outcomes highlight that the multidisciplinary approach was successful in preserving the natural tooth with good periodontal health conditions.

Anterior Upper Teeth Golden Proportion Analysis with Millimetric Templates: An Invention Developed at Londrina State University.

In order to achieve aesthetic and harmonious smile results, the use of anterior upper teeth golden proportion concepts represents reliable and scientific based guidelines. However, measuring, recording and analysing teeth and smiles biometric values proves to be a clinical and laboratory routine chalenge, once it is time consuming and demands additional especific math calculus or formulas. The aim of this paper is present an invention, "anterior upper teeth golden proportion millimetric templates," a set of instruments fabricated in order to achieve precise and fast millimetric measures, once they present predefined geometrical drawings and diagrams. Currently, when planning aesthetic tooth size modifications treatments, tools are used as pachymeters, dry edge compass, or some softwares. Most of times this strategy relies on professional expertise and intuiton, which shows to be limitating factors with the need of trial-and-error training and an accurate critical and artistic sense. Unfortunately, this is not inherent to all professionals, especially undergraduate dental school students. Thus, the templates bring differentials and advantages, being versatile and convenient, allowing countless clinical and laboratory uses, even over a cellphone or a computer screen. An excellent diagnostic aid providing ideal teeth proportions and positioning, increasing the chances of success in dental treatment planning.

Clinical performance of resin composite restorations placed by dental students: a retrospective, cross-sectional, and observational study

Aim: A retrospective, cross-sectional study was carried out to evaluate the performance of resin composite restorations placed by undergraduate dental students with 1 to 15 years of placement based on dental records. Methods: Four calibrated operators evaluated 498 restorations (anterior and posterior) of 120 patients according to Ryge's validated criteria (USPHS). Results: The criteria that showed the smallest changes between the types of failures were color matching, marginal discoloration and surface texture. Regarding the longevity, the surface texture showed an increase in the frequency of failures from the second time interval (3.1 to 6 years). Higher prevalence of failure was found in class II and III restorations, with secondary caries being the main reason. No significant differences were found for anatomic form, marginal adaptation, and color matching. Class V restorations showed a higher fracture rate with total displacement of the restoration, with no increase in the frequency of fracture over time. Conclusion: High rate of restoration failure was observed, possibly due to the lack of experience and skills of the students. This outcome highlight the need for continuous revision and improvements of teaching practice regarding the development of clinical competences and skills by dental students

Direct Resin Composite Restoration in Anterior Tooth: 10 Years of Clinical Follow-Up

The emergence and development of resin-based materials, such as resin composites and adhesive systems, have shifted the restorative treatment of anterior teeth with caries lesions and/or fractures. Thus, based on the disadvantages of indirect restorations, direct esthetic restorations are restorative options even for anterior teeth with exten sive loss of hard tissues. This study aimed to describe and discuss the direct resin composite restoration performed to solve the esthetic and functional impairments of the upper anterior teeth with diastemas. The upper left central incisor received total crown preparation for indirect restoration. Clinical results after 10 years were recorded. Considering the clinical characteris tics of dental restorations, it is possible to conclude that direct resin composite restorations reestablished the esthetic and functional properties satisfactorily, even in a tooth with extensive coronal destruction. The success of the restorative treatm ent was dependent on factors related to the materials´ properties, oral habits of the patient, and mostly the clinical skills of th e dental clinician.

La aparición y el desarrollo de materiales con base de resina, como las resinas compuestas y los sistemas adhesivos, han cambiado el tratamiento restaurador de los dientes anteriores con lesiones de caries y/o fracturas. Por lo tanto, en base a las desventajas de las restauraciones indirectas, las restauraciones estéticas directas son opciones de restauración, incluso para los dientes anteriores con una gran pérdida de tejidos duros. Este estudio tuvo como objetivo describir y discutir la restauración directa con resina compuesta, realizada para solucionar las deficiencias estéticas y funcionales de los dientes anteriores superiores con diastemas. El incisivo central superior izquierdo recibió preparación de corona total para restauración indirecta. Se registraron los resultados clínicos después de 10 años. Considerando las características clínicas de las restauraciones dentales, es posible concluir que las restauraciones directas en resina compuesta restablecieron las propiedades estéticas y funcionales satisfactoriamente, incluso en un diente con destrucción coronal extensa. El éxito del tratamiento restaurador dependió de factores relacionados con las propiedades de los materiales, los hábitos bucales del paciente y, sobre todo, las habilidades clínicas del odontólogo.

LED photobiomodulation effect on the bleaching-induced sensitivity with hydrogen peroxide 35%-a controlled randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate the effect of a protocol of photobiomodulation (PBM) with light-emitting diodes (LED) on the clinical risk of bleaching-induced sensitivity. MATERIALS AND METHODS: Sixty-four volunteers were selected and randomly divided in two groups, placebo (PG) and LED (LG). The LG received PBM irradiation and tooth bleaching, while the PG received tooth bleaching and simulation of the irradiation. The occurrence of painful sensitivity was recorded during the dental bleaching; immediately after bleaching; and 24, 48, and 72 h after tooth bleaching. At the same measurement times, data were collected on the intensity of sensitivity (VAS and NRS scale) and teeth affected by bleaching-induced sensitivity. A questionnaire sought to measure how the painful sensitivity influenced basic daily activities. Tooth color measures were performed using subjective and objective methods. RESULTS: LED irradiation decreased the occurrence of sensitivity at all studied evaluation times as well as its intensity, with the exception of the 72-h data when both groups presented no difference. Teeth affected by bleaching-induced sensitivity were significantly greater in the PG. Color measurements presented no differences between the groups in the recently after and later measures. CONCLUSIONS: PBM with LED decreases sensitivity risk and sensibility intensity during and after office bleaching and causes no influence on the shade degree of whitening achieved. The decrease in tooth sensitivity provided more comfort and less suffering while drinking. CLINICAL RELEVANCE: LED irradiation is a promising intervention in the control of bleaching-induced sensitivity. TRIAL REGISTRATION: RBR-7hpfwj. Sensitivity intensity measured by the VAS scale (0-10) in the first whitening session (Graphic A) and second whitening session (Graphic B). Significance level set at ≤ 5%. *Mann-Whiteney U test. Columns followed by the same letter are significant different (ap < 0.001; bp < 0.001; cp < 0.001; dp =0.013; ep < 0.001; fp < 0.001; gp < 0.001; hp = 0.002).

Fiber-reinforced fixed dental prosthesis to replace missing anterior teeth: case reports.

The direct fiber-reinforced fixed dental prosthesis (FRFDP) is a minimally invasive approach to replacing missing anterior teeth, offering good survival rates and sound mechanical properties. This report describes the placement and 12-month follow-up results of FRFDPs used to replace missing anterior teeth in 2 patients. In the first case, the extraction of the maxillary right central incisor was related to trauma. In the second case, severe periodontal disease necessitated the extraction of the mandibular left central incisor. Based on the biological and financial considerations of the patients and the need to obtain clinical resolution in a short time, placement of an FRFDP was proposed in each case. Each patient was informed of the benefits and limitations of an FRFDP and accepted the treatment plan. In each case, an FRFDP was placed immediately after the surgical extraction of the incisor, using the extracted tooth as a pontic. The results observed at the 12-month follow-up examinations of the patients suggest that the FRFDP is a viable, esthetic, and functional option to replace missing anterior teeth.

Clinical Evaluation of Composite Resin Restorations in Posterior Teeth / Avaliação Clínica de Restaurações de Resina Composta em Dentes Posteriores

Factors such as aesthetics and adhesion to dental substrates have consolidated composite resin as a restorative material for posterior teeth, however, the performance is unsatisfactory regarding the longevity of these restorations. The purpose of this retrospective cross-sectional observational study was to evaluate the reasons that resulted in failure of class I and II Black composite resin restorations, performed by undergraduate dental students at the State University of Londrina. The patients were selected from the research of the medical charts filed at the University Dental Clinic's Screening Department. The restorations were evaluated by two calibrated dentists. The data collected were tabulated and analyzed using descriptive statistics, function Cont IF. Of the 261 class I and II restorations evaluated, 150 (57.5%) were in need of replacement. The main causes of failure of class I and II restorations were secondary caries (46.7%), followed by fracture (19.3%) and loss of marginal adaptation (16.7%). Of all the restorations made by the 3rd grade students, 68.4% failed, 57.4% performed by the 4th grade students and 53.9% of the 5th grade students. Based on the results, it is concluded that the main reasons for restorations failure were secondary caries, fracture and loss of marginal adaptation according to the evaluation criteria. Restorations performed by students in the 3rd grade showed a higher percentage of failures compared to those performed by students in the 4th and 5th grades. (AU)

Fatores como estética e adesão aos substratos dentários têm consolidado a resina composta como material restaurador para dentes posteriores, entretanto, o desempenho mostra-se insatisfatório em relação a longevidade destas restaurações. O objetivo desse estudo observacional transversal retrospectivo foi avaliar as razões que resultaram em falhas das restaurações de resina composta de classe I e II de Black, realizadas por alunos de graduação em Odontologia da Universidade Estadual de Londrina. Os pacientes foram selecionados a partir da pesquisa dos prontuários arquivados no Setor de Triagem da Clínica Odontológica Universitária. As restaurações foram avaliadas por dois avaliadores, cirurgiões-dentistas, calibrados. Os dados coletados foram tabulados e analisados por meio de estatística descritiva, função ContSE. Das 261 restaurações classes I e II avaliadas, 150 (57,5%) apresentavam-se com necessidade de substituição. As principais causas de falhas das restaurações classes I e II foram: cárie secundária (46,7%), seguido de fratura (19,3%) e perda de integridade marginal (16,7%). Dentre as restaurações realizadas por alunos da 3ª série e avaliadas, 68,4% falharam, da 4ª série 57,4% e da 5ª série 53,9%. Com base nos resultados, conclui-se que as principais razões de falha das restaurações foram cárie secundária, fratura e perda de integridade marginal, de acordo com os critérios de avaliação. As restaurações realizadas por alunos da 3ª série apresentaram maior percentual de falhas, comparadas as realizadas pelos alunos da 4ª e 5ª séries. (AU)

Microporosity and polymerization contraction as function of depth in dental resin cements by X-ray computed microtomography.

This research aimed to obtain the depth dependence of polymerization contraction and microporosity from irradiated dental resin cements by X-ray computed microtomography (µCT). Samples (n = 5) of commercial Relyx U200 (RU) and AllCem Core (AC) dual-cure resin cements were injected in a cylindrical Teflon sampler (25 mm3 ) and separated according to polymerization mechanism: self-cured (not irradiated) and dual-cured (irradiated from the top surface with a LED device). The cement's volume was scanned with the µCT scanning conditions kept constant. To assess the depth dependence of polymerization contraction, it was measured the displacement of the cement mass from the sample holder at 30 vertical cuts (0.1 mm distant). To probe the microporosity, the percentage of area with presence of porosity by slice was obtained. All data were statistically treated. It was observed a positive linear correlation between depth and polymerization contraction in the irradiated groups. In the other hand, the concentration of micropores decreased with increasing depth. Furthermore, the composition of the resin cement was determinant for the correlation's coefficients of these physical properties with depth. The µCT technique showed to be useful to probe physical properties of dental restorative materials that influence in the clinical outcomes, revealing that, for thin specimens, when light cured the RU cement presented mechanical behavior more favorable for clinical applications.

Microstructural effect of a laser-activated bleaching agent containing titanium dioxide on human enamel.

AIM: This study aimed to evaluate the effect of a laser-activated bleaching agent containing titanium dioxide (TiO2) nanoparticles on enamel roughness and hardness. MATERIALS AND METHODS: Twenty human premolars were randomized into two groups according to the bleaching treatments performed: HP - 35% hydrogen peroxide and HP + TiO2 - 30% hydrogen peroxide containing TiO2 light-activated by diode laser (980 nm). It was performed two bleaching sessions with an interval of 7 days. Microhardness and roughness of the enamel were assessed at three times: T0 - Before 1st appointment, T1 - after 2nd appointment, and T2-7 days after 2nd appointment. RESULTS: The HP + TiO2 did not cause changes on enamel roughness and hardness and presented the same effects of the HP. CONCLUSIONS: Both bleaching agents showed no difference between them. Then, it is possible to conclude that both are viable for clinical use during in-office dental bleaching technique regarding the microstructural changes that they might cause.

Direct composite resin restorations for teeth with dental erosion: a case report.

Acid erosion should be treated according to its multifactorial etiology. This case report describes a patient with tooth wear caused by daily intake of acidic carbonated beverages. After meticulous clinical and radiographic analysis, the clinician restored the teeth temporarily with chemically cured glass ionomer cement. Afterward, the patient underwent basic periodontal therapy with scaling and coronal polishing. The patient received guidance regarding daily oral hygiene and eating habits to control the ingestion of acidic drinks. After reestablishing adequate oral conditions, the clinician placed direct composite resin restorations on the maxillary anterior teeth that displayed dental erosion. The clinical procedures improved the patient's oral health as well as the form, esthetics, and function of the worn teeth.

Effect of light-curing protocols on the mechanical behavior of bulk-fill resin composites.

OBJECTIVE: To investigate the effect of two light-curing protocols on mechanical behavior of three bulk-fill resin composites (BFRC) considering their optical properties. METHODS: One increment of 4 mm thickness of the bulk-fill resin composites Opus Bulk Fill, Tetric N-Ceram and Filtek Bulk Fill Flow were submitted to two different light-curing protocols: Sp - irradiance of 1000 mW/cm2 (20 s); Xp - irradiance of 3200 mW/cm2 (6 s). To assess the influence on the mechanical behavior it was studied polymerization shrinkage by X-ray microtomography (n = 3), Vickers hardness (n = 10) at the top and bottom surfaces of the samples, irradiance reaching the bottom surface (n = 3) and absorbance spectrum during the light-curing time interval (n = 3). Data were analyzed by two-way ANOVA test for parametric data and Kruskal Wallis test, followed by Wilcoxon or Mann-Whitney U post-test, for non-parametric data. RESULTS: All BFRCs contracted when light-cured, with greater contraction for Xp. Filltek Bulk Fill Flow showed highest polymerization shrinkage, for both Sp and Xp. All BFRCs showed minor hardness values on the bottom surface, with greater reduction for Xp. All BFRCs exhibited a decrease in irradiance at 4 mm depth. A decrease in absorbance intensity throughout the light-cure was observed, except for Opus Bulk Fill. CONCLUSIONS: Regardless BFRCs composition, the light-curing protocol with lower irradiance and longer exposure time results in lower polymerization shrinkage and higher hardness. The higher irradiance in a shorter time interval compromises the mechanical behavior of the resin composites, which may result in undesirable clinical outcomes.

Perfil, atuação e satisfação de cirurgiões-dentistas em Residências Multiprofissionais em Saúde da região Sul do Brasil / Profile, performance, and satisfaction of Dentists in Multiprofessional Health Residences in Southern Brazil

As Residências Multiprofissionais em Saúde (RMS) encontram-se distribuídas por todo o território nacional e estão estruturadas em abordagem multiprofissional com uma visão mais humana e abrangente, cujo foco não se restringe apenas aos procedimentos curativos. O objetivo do presente estudo foi avaliar o perfil dos cirurgiões-dentistas regularmente matriculados em RMS da região Sul do país, bem como sua atuação e satisfação com os programas. Para isso, foi realizada uma pesquisa quantitativa, exploratória e descritiva, utilizando-se um questionário on-line, cujo link foi enviado a cirurgiões-dentistas matriculados em RMS (Atenção Básica, Saúde da Família e Comunidade e Saúde Coletiva), localizadas na região Sul do Brasil. Os dados coletados foram tabulados no Microsoft Excel® e tratados por estatística descritiva (frequência simples e relativa). Constatou-se que a maioria dos residentes era do gênero feminino (75%) com graduação em IES privada (70%), sem experiência profissional prévia (70%) e com experiência acadêmica prévia em saúde pública (85%). Para os dados referentes à RMS, a maioria relatou como motivo pela escolha da residência o interesse em atuar na atenção básica. Oitenta e cinco por cento dos dentistas relataram atuar em Unidades Básicas de Saúde. A maioria dos residentes mostrou-se satisfeito com a RMS (75%) e a falta de capacitação dos docentes foi apontada como a principal fragilidade dos programas. O estudo possibilitou traçar um panorama do perfil, atuação e satisfação dos cirurgiões-dentistas inseridos em RMS da região Sul do Brasil. Os dados podem auxiliar na melhoria das práticas e organização das RMS com cirurgiões-dentistas, conduzindo melhor a atuação de residentes e docentes frente às principais fragilidades apontadas (AU).

Multi-professional Health Residences (MHR) are distributed throughout the national territory and have an approach with a more human, comprehensive vision and whose focus is not restricted to therapeutic procedures. Therefore, the present study aimed to evaluate the professional profile of dentists in MHR in southern Brazil, as well as their performance and satisfaction with the residency program. Thus, quantitative, exploratory and descriptive research was carried out using an online questionnaire, whose link was sent to all dentists attending MHR in South Brazil. Subsequently, the data collected were tabulated in the Microsoft Excel® and treated by descriptive statistics analysis. Among the main results of personal and professional profiles, the majority of the residents were female (75%) with a degree in private Higher Education Institutions (70%), without prior professional experience (70%) and with previous academic experience in Public health (85%). For MHR data, the majority reported the interest in acting in the primary health care as a reason for choosing the residence. Concerning the place of performance, the Primary Health Unit represented 85%. Most residents were satisfied with MHR (75%) and reported the lack of teacher training as the main program weakness. Therefore, with this study, it was possible to draw a panorama of the professional profile and the performance of dentists inserted in MHR in Southern Brazil. Furthermore, data can support and improve the practices and organization of MHR with dentists, leading to better performance of residents and teachers in the main weaknesses pointed out (AU).

In Vitro Evaluation of the Remineralizing Potential and Antimicrobial Activity of a Cariostatic Agent with Silver Nanoparticles.

Cariostatic treatment has been shown to successfully arrest caries. However, it blackens the carious tooth structure. This study evaluated the effects of an experimental cariostatic agent with silver nanoparticles (Ag-Nano) using microhardness (MH) and microbiological tests. The cariostatic agents tested were: Saforide®, Cariestop®, Ancarie® and Ag-Nano. Sixty-six samples from deciduous enamel were submitted to initial (after pH cycling to obtain initial caries-like lesion) and final (after cariostatic application) MH testing and %MH values were calculated. After longitudinal sectioning, internal (I) MH was evaluated. Strains of Streptococcus mutans, Escherichia coli, and Enterococcus faecalis in brain-heart infusion culture were treated with the cariostatic agents. Agar diffusion tests (ADTs) were performed and minimum inhibitory concentrations were determined. The statistical tests used were: Kruskal-Wallis and Dunn (%MD; ADT; MIC) and ANOVA followed by Tukey's test (I-MH) (p<0.05). The %MH of Saforide® was significantly greater than that of Ag-Nano (p<0.05). Internal MH showed progressive improvement in the enamel remineralization for all cariostatic tested. In ADTs showed greater inhibition of S. mutans, E. faecalis, and E. coli by Saforide® than by Ancarie® and Ag-Nano. Ag-Nano was able to inhibit 100% microorganism growth at a lower concentration than required for the other agents. It was concluded that Ag-Nano treatment promoted remineralization of deciduous tooth enamel with initial caries-like lesion and bactericidal activity.

In Vitro Evaluation of the Remineralizing Potential and Antimicrobial Activity of a Cariostatic Agent with Silver Nanoparticles

Abstract Cariostatic treatment has been shown to successfully arrest caries. However, it blackens the carious tooth structure. This study evaluated the effects of an experimental cariostatic agent with silver nanoparticles (Ag-Nano) using microhardness (MH) and microbiological tests. The cariostatic agents tested were: Saforide®, Cariestop®, Ancarie® and Ag-Nano. Sixty-six samples from deciduous enamel were submitted to initial (after pH cycling to obtain initial caries-like lesion) and final (after cariostatic application) MH testing and %MH values were calculated. After longitudinal sectioning, internal (I) MH was evaluated. Strains of Streptococcus mutans, Escherichia coli, and Enterococcus faecalis in brain-heart infusion culture were treated with the cariostatic agents. Agar diffusion tests (ADTs) were performed and minimum inhibitory concentrations were determined. The statistical tests used were: Kruskal-Wallis and Dunn (%MD; ADT; MIC) and ANOVA followed by Tukey's test (I-MH) (p<0.05). The %MH of Saforide® was significantly greater than that of Ag-Nano (p<0.05). Internal MH showed progressive improvement in the enamel remineralization for all cariostatic tested. In ADTs showed greater inhibition of S. mutans, E. faecalis, and E. coli by Saforide® than by Ancarie® and Ag-Nano. Ag-Nano was able to inhibit 100% microorganism growth at a lower concentration than required for the other agents. It was concluded that Ag-Nano treatment promoted remineralization of deciduous tooth enamel with initial caries-like lesion and bactericidal activity.

Resumo O tratamento com cariostático tem demostrado sucesso na paralização da cárie. No entanto, causa escurecimento da estrutura dental cariada. Este estudo avaliou os efeitos de um agente cariostático experimental com nanopartículas de prata (Ag-Nano) através de microdureza (MD) e testes microbiológicos. Os cariostáticos testados foram: Saforide®, Cariestop®, Ancarie® e Ag-Nano. Sessenta e seis amostras de esmalte decíduo foram submetidos a MD inicial (após ciclagem de pH para obtenção da lesão de cárie inicial) e final (após aplicação dos cariostáticos), e os valores da porcentagem (%) de MD foram calculados. Após secção longitudinal, a MD interna (I) foi avaliada. Cepas de Streptococcus mutans, Escherichia coli e E. faecalis foram cultivados em ágar infusão de cérebro e coração (BHI) e submetidos aos cariostáticos testados. Além disso, foram realizados teste de difusão em ágar (TDA) e avaliação da concentração mínima inibitória (CIM) dos cariostáticos. Os testes estatísticos usados foram: Kruskall-Wallis e Dunn (%MD; TDA; CIM) e ANOVA seguido de teste de Tukey (MD-I) (p<0.05). A %MD do Saforide® foi significativamente maior do que a de Ag-Nano (p<0,05). A MD interna apresentou melhora progressiva na remineralização do esmalte para todos os cariostático testados. Os resultados do TDA mostraram que S. mutans, E. faecalis e E. coli sofreram maior inibição pelo Saforide® (p<0,05), em relação ao Ancarie® e Ag-Nano. No entanto, para o teste de CIM o Ag-Nano foi capaz de inibir 100% dos microorganismos, em menor concentração do que os demais cariostaticos. Conclui-se que, o tratamento Ag-Nano foi capaz de promover remineralização do esmalte dental decíduo com lesão de cárie inicial e apresentou atividade bactericida.

Smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation.

OBJECTIVES: This study evaluated smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation. MATERIALS AND METHODS: Forty-five extracted uniradicular human mandibular premolars with single canals were treated endodontically. The cervical and middle thirds of the fillings were then removed, and the specimens were divided into 9 groups: G1, saline solution (NaCl); G2, 2.5% sodium hypochlorite (NaOCl); G3, 2% chlorhexidine (CHX); G4, 11.5% polyacrylic acid (PAA); G5, 17% ethylenediaminetetraacetic acid (EDTA). For the groups 6, 7, 8, and 9, the same solutions used in the groups 2, 3, 4, and 5 were used, respectively, but activated with ultrasonic activation. Afterwards, the roots were analyzed by a score considering the images obtained from a scanning electron microscope. RESULTS: EDTA achieved the best performance compared with the other solutions evaluated regardless of the irrigation method (p < 0.05). CONCLUSIONS: Ultrasonic activation did not significantly influence smear layer removal.

The influence of polymerization type and reinforcement method on flexural strength of acrylic resin.

The aim of this study was to evaluate the flexural strength of acrylic resin bars by varying the types of resin polymerization and reinforcement methods. Fourteen groups (N=10) were created by the interaction of factors in study: type of resin (self-cured (SC) or heat-cured (HC)) and reinforcement method (industrialized glass fiber (Ind), unidirectional glass fiber (Uni), short glass fiber (Short), unidirectional and short glass fiber (Uni-Short), thermoplastic resin fiber (Tpl), and steel wire (SW)). Reinforced bars (25×2×2 mm) were tested in flexural strength (0.5 mm/min) and examined by scanning electron microscopy (SEM). Data (MPa) were submitted to factorial analysis, ANOVA, and Tukey and T-student tests (a=5%) showing significant interaction (P=0.008), for SC: Uni (241.71±67.77)a, Uni-Short (221.05±71.97)a, Ind (215.21±46.59)ab, SW (190.51±31.49)abc, Short (156.31±28.76)bcd, Tpl (132.51±20.21)cd, Control SC (101.47±19.79)d and for HC: Ind (268.93±105.65)a, Uni (215.14±67.60)ab, Short (198.44±95.27)abc, Uni-Short (189.56±92.27)abc, Tpl (161.32±62.51)cd, SW (106.69±28.70)cd, and Control HC (93.39±39.61)d. SEM analysis showed better fiber-resin interaction for HC. Nonimpregnated fibers, irrespective of their length, tend to improve fracture strength of acrylics.

Longevidade de clareamento em dente não vital com associação de técnicas: relato de caso / Longevity of nonvital tooth bleaching with a combination of techniques. Case report

O clareamento dentário, por ser um tratamento não invasivo e de baixo custo, representa uma excelente opção de tratamento para dentes com alteração cromática. O propósito desse artigo é relatar um caso clínico com associação de técnicas de clareamento para dentes não vitais e discutir as implicações clínicas imediatas e mediatas. Paciente do sexo masculino, 30 anos de idade, procurou o serviço odontológico da Universidade Estadual de Londrina para tratamento estético do dente 21, diagnosticado com escurecimento após traumatismo e tratamento endodôntico. Diante do exame radiográfco, que não mostrou alterações da normalidade, foi instituído o clareamento dentário intracoronário com pasta clareadora de perborato de sódio e peróxido de hidrogênio a 20% (6 sessões, com intervalo de 7 dias), seguido por clareamento intra- e extracoronário com peróxido de hidrogênio a 35% (3 sessões de 20 minutos ininterruptos, com intervalo de 7 dias). Passados 10 dias da última sessão de clareamento, foi confeccionada restauração da face palatina com resina composta. Também foi feito controle clínico e radiográfco após 18 meses. O resultado obtido demonstrou a longevidade do procedimento realizado. Assim,conclui-se que o clareamento de dentes não vitais é seguro,efcaz e, quando necessário, pode ser realizado com diferentes produtos, aplicados por diferentes técnicas.

Tooth bleaching, as a non-invasive and low cost treatment,provides an excellent option for teeth with color change. The purpose of this study is to report a case with a combination of techniques for nonvital teeth bleaching and discuss the immediate and mediate clinical implications. Male patient,30 year-old, came to the dental service at the State University of Londrina for esthetic treatment of tooth #21, diagnosed with severe darkening after trauma accentuated by endodontic treatment. Radiographic examination showed no alterations of normality. It was established a treatment with intracoronal bleaching techniques, using sodium perborate with 20% hydrogen peroxide (6 sessions every 7 days), followed by intra- and extracoronal bleaching with 35% hydrogen peroxide (3 sessions of 20 minutes every 7 days). Restoration with composite resin for the fnal sealing of the cavity was made 10 days after the end of bleaching. Clinical and radiographic control after 18 months also were performed.The result showed the longevity of the procedure. Therefore it can be conclude that the nonvital bleaching is safe, effective and can be performed with different products, applied by different techniques

Aparelhos fotopolimerizadores: evolução e aplicação clínica - uma revisão da literatura / Light-curing units: evolution and clinical application - a literature review

Devido ao surgimento das resinas compostas fotopolimerizáveis no mercado, foi desenvolvida, ao longo dos anos, uma variedade de tecnologias para se produzir a luz necessária para a ativação desses materiais. Frente à importância da qualidade da luz na fotopolimerização dos compósitos, este trabalho tem como objetivo, com base na literatura correlata, apresentar alguns conceitos fundamentais referentes à reação de polimerização das resinas compostas e a relação que há entre as características dos aparelhos fotopolimerizadores, a luz emitida e o comportamento clínico das restaurações de resina composta. Assim, podemos concluir que, independentemente do sistema empregado, a intensidade da luz emitida pelo aparelho fotopolimerizador é de suma importância para a longevidade clínica dos procedimentos restauradores realizados. E, além disso, os aparelhos à base de LED representam uma tecnologia promissora, comparados aos aparelhos de luz halógena, os quais ainda são bastante utilizados.

Due to the emergence of light cure composite resins on the market, was developed over the years a variety of technologies to produce the necessary light for activation of these materials. Based on the importance of the quality of light, when the curing of composites, this paper aims, based on related literature, to present some fundamental concepts concerning to the polymerization of composite resins and the relationship between the characteristics of light curing units, light emitted and clinical behavior of resin composite restorations. Thus, we conclude that, whatever the system employed, the light intensity emitted by the curing unit is very important for the clinical longevity of restorative procedures performed. Furthermore, the LED light units represent a promissory technology, compared to the quartz-tungsten halogen, that are very used yet.

Manchamento de uma resina composta e sua relação com o efeito da intensidade da luz emitida por aparelhos fotopolimerizadores de lâmpada halôgena / Staining of a composite resin and its relation to the effect of intensity of light emitted by halogen light curing units

O manchamento pode comprometer a longevidade clínica das restaurações em resina composta. Assim, este estudo avaliou o grau de alteração de cor de uma resina composta, em função da potência da luz emitida pelos aparelhos fotopolimerizadores de lâmpada halógena de quartzo-tungstênio, utilizados na Clínica Odontológica Universitária da Universidade Estadual de Londrina (COU-UEL). Com auxílio de uma matriz metálica foram confeccionados 60 corpos-de-prova, divididos em quatro grupos experimentais (n=15), de acordo com a potência da luz emitida pelos aparelhos (Grupo 1 - 183,88 mW/ cm2, Grupo 2 - 282,55 mW/cm2 , Grupo 3 - 303,00 mW/cm2 e Grupo 4 - 434,10 mW/ cm2 ). Em seguida, por 24 horas, os corpos-de-prova foram mantidos imersos em ambiente contendo água deionizada, em estufa a temperatura de 37º+2ºC. Após, foram acomodados no compartimento de amostra do espectrofotômetro da marca X-Rite, modelo SP62, para registro da cor inicial. Passados 30 dias, mantidos em água deionizada, a temperatura de 60º+1ºC, nova leitura da cor foi realizada. Concluiu que, quanto à variável intensidade de luz, não houve alteração (p=0,2468; ANOVA) de cor da resina composta entre os grupos

The staining can affect the clinical longevity of composite resin restorations. This study evaluated the degree of color change of a composite resin, depending on the intensity of emitted light curing of quartz-halogen tungsten, used in Dental Clinic of the State University of Londrina. With the aid of a metal matrix were made 60 bodies of proof, divided into four experimental groups (n = 15), according to the power of the emitted light (Group 1 - 183,88mW/cm2 , Group 2 - 282,55mW/ cm2 , Group 3 -303,00mW/cm2 and Group 4 - 434,10mW/cm2 ) . Then, for 24 hours, the bodies of proof environment were kept immersed in deionized water, incubated at 37º+2º. After, they were accommodated in the sample compartment of the spectrophotometer X-Rite brand, model SP62, to record initial color. After 30 days, kept in deionized water, the temperature of 60º+1ºC, new color reading was held. Concluded that as the variable light intensity did not change (p = 0.2468; ANOVA) color composite resin between the groups

Análise de radiômetros manuais para aparelhos fotopolimerizadores / Light curing units effectiveness assessed by dental radiometers

Avaliar o desempenho de radiômetros manuais e a qualidade da luz emitida por aparelhosfotopolimerizadores: um de lâmpada halógena (Optilux 401) e dois à base de LED (LE.Demteron I e Bluephase). Foram verificados os valores de intensidade de luz, potência e comprimento de onda da luz emitida por esses aparelhos. Cinco marcas comerciais de radiômetros manuais foram analisadas quanto ao desempenho utilizando-se as mesmas fontes de luz selecionadas. Três radiômetros de cada marca comercial foram utilizados para o estudo. Também foi realizada a inspeção das características internas dos equipamentos. E, por fim, as informações foram comparadas com as relatadas pelos fabricantes. A avaliação da intensidade de luz foi realizada com os radiômetros manuais e registrou-se a potência com o equipamento Power Meter Ophir. Para avaliar o comprimento de onda foi utilizado um espectrômetro USB2000. Os valores de intensidade de luz revelaram grande variabilidade nas médias obtidas com todos os radiômetros (p

Analyzing three light-curing units, being one was a halogen system and two based on LEDs.It was checked the values of light intensity, power and wavelength of the light emitted by Ithese light-curing units. Five brands of commercial manual radiometer have been evaluated for performance using the same Curing. The inspection of the internal characteristics of the light-curing units also was realized. Finally, the data were compared with those reported by manufactures. The evaluation of light intensity was performed using a five manual radiometer and the power was registered with the equipment Power Meter Ophir (Ophiropt). Evaluating the wavelength of light emitted by the light-curing units a USB2000 spectrometer (Ocean Optics) was used. The results of light intensity showing great variability in the averages obtained with ali radiometers (p