Effect of thermocycling on internal microhardness of high and low viscosity bulk fill composite resins in class I cavities / Efeito da termociclagem na microdureza interna de resinas compostas bulk fill de alta e baixa viscosidade aplicadas em cavidades classe I

ABSTRACT Objective: To evaluate the effect of thermocycling on the Knoop internal microhardness of high- and low viscosity bulk fill resins applied in Class I cavities. Methods: Thirty third molars with Class I cavity preparations were randomly divided into 3 groups according to the restorative system: nanoparticulated composite resin (Filtek™ Z350 XT 3M ESPE) (oblique increments of 2mm); low viscosity bulk fill resin (Filtek™ Bulk fill Flow, 3M ESPE) (3mm increments covered with a 1-mm layer of nanoparticulated resin); high viscosity bulk fill resin (Filtek™ Bulk fill, 3M ESPE) (single 4-mm increment). After 24h, half of samples was submitted to thermocycling (1,000 cycles). All samples (n=5) were sectioned in half to measure the internal microhardness at bottom and top of restoration. Results: Analysis of variance indicated that, for nanoparticulated composite resin, without thermocycling, the microhardness at the top was statistically lower than at the bottom. After thermocycling, there was no difference in microhardness between the top and the bottom. For low viscosity bulk fill resin, without thermocycling, there was no significant difference in microhardness means between the top and the bottom. After thermocycling, significantly higher microhardness was found at the top than at the bottom (p <0.05). For high viscosity bulk fill resin there was no significant difference between the microhardness values at the top and bottom, regardless of thermocycling (p> 0.05). In all composite resins, an increase in microhardness was observed after thermocycling (p <0.05). Conclusion: Thermocycling increased the internal microhardness of resin restorations, and, for the low viscosity bulk fill resin, the microhardness at the top was higher than at the bottom after thermocycling.

RESUMO Objetivo: Avaliar o efeito da termociclagem na microdureza Knoop interna de resinas bulk fill de alta e baixa viscosidade aplicadas em cavidades classe I. Métodos: Trinta terceiros molares com cavidades Classe I foram divididos aleatoriamente em três grupos de acordo com o sistema restaurador: Resina composta nanoparticulada (Filtek™ Z350 XT 3M ESPE) (incrementos oblíquos de 2mm); resina bulk fill de baixa viscosidade (Filtek™ Bulk fill Flow, 3M ESPE) (incremento de 3mm mais 1mm de resina nanoparticulada); resina bulk fill de alta viscosidade (Filtek ™ Bulk fill, 3M ESPE) (único incremento de 4mm). Após 24h, metade das amostras foi submetida a termociclagem (1.000 ciclos). Todas as amostras (n=5) foram seccionadas ao meio para mensuração da microdureza interna na base e topo da restauração. Resultados: Análise de variância indicou que, para a resina composta nanoparticulada e antes da termociclagem, a microdureza no topo foi estatisticamente inferior do que na base (p<0,05). Após a termociclagem, não houve diferença entre topo e base. Já para a resina bulk fill de baixa viscosidade, antes da termociclagem, não se constatou diferença significativa nos valores de microdureza entre topo e base. Após termociclagem, valores significativamente mais elevados de microdureza foram encontrados no topo do que na base (p<0,05). Para resina bulk fill de alta viscosidade, não houve diferença significativa na microdureza entre topo e base, realizando-se ou não termociclagem (p>0,05). Em todas as resinas compostas foi verificado aumento de microdureza após termociclagem (p<0,05). Conclusão: A termociclagem aumentou a microdureza para todas as resinas compostas, sendo que para a resina bulk fill de baixa viscosidade a microdureza no topo foi maior do que na base após termociclagem.

TiO2 nanotube-containing glass ionomer cements display reduced aluminum release rates.

Titanium dioxide nanotubes (TiO2-nts) were incorporated into a glass ionomer cement (GIC) with improved mechanical properties and antibacterial activity. The aims of the present in vitro study were to define the elemental characterization, aluminum (Al) release rate, and initial working time for GIC reinforced with TiO2-nts, in an experimental caries model. TiO2-nts were incorporated into GIC powder components at 5% by weight, and compared with unblended GIC. Experimental approaches used energy-dispersive spectrometry (EDS), atomic absorption spectrophotometry (AAS), and brightness loss to define surface element properties, Al release rates, and initial working time, respectively. Statistical analysis was performed by 2-way ANOVA, Tukey's test, generalized linear models, and Student's t test (a = 0.05). EDS data analysis revealed that TiO2-nts incorporated into GIC had no significant impact on the typical elemental composition of GICs in an in vitro caries model. Regarding the demineralizing solution, GIC with TiO2-nt significantly decreased the Al release rate, compared with the control group (p < 0.0001). Moreover, TiO2-nt incorporated into GIC did not alter the initial working time of the material (p > 0.05). These findings add information to our scientific body of knowledge concerning the potential impact of TiO2-nt on the performance of conventional GICs.

TiO2 nanotube-containing glass ionomer cements display reduced aluminum release rates

Abstract Titanium dioxide nanotubes (TiO2-nts) were incorporated into a glass ionomer cement (GIC) with improved mechanical properties and antibacterial activity. The aims of the present in vitro study were to define the elemental characterization, aluminum (Al) release rate, and initial working time for GIC reinforced with TiO2-nts, in an experimental caries model. TiO2-nts were incorporated into GIC powder components at 5% by weight, and compared with unblended GIC. Experimental approaches used energy-dispersive spectrometry (EDS), atomic absorption spectrophotometry (AAS), and brightness loss to define surface element properties, Al release rates, and initial working time, respectively. Statistical analysis was performed by 2-way ANOVA, Tukey's test, generalized linear models, and Student's t test (a = 0.05). EDS data analysis revealed that TiO2-nts incorporated into GIC had no significant impact on the typical elemental composition of GICs in an in vitro caries model. Regarding the demineralizing solution, GIC with TiO2-nt significantly decreased the Al release rate, compared with the control group (p < 0.0001). Moreover, TiO2-nt incorporated into GIC did not alter the initial working time of the material (p > 0.05). These findings add information to our scientific body of knowledge concerning the potential impact of TiO2-nt on the performance of conventional GICs.

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence

Abstract This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Titanium dioxide nanotubes incorporated into bleaching agents: physicochemical characterization and enamel color change

Abstract Titanium dioxide nanotubes are nanostructures that can accelerate the oxidation reaction of bleaching procedures and promote a more effective whitening effect. Objective This study evaluated physicochemical properties of bleaching agents incorporated with titanium dioxide (TiO2) nanotubes, and the effects on tooth color change at different periods. Methodology 40 premolars were treated according to the following groups (n=10): CP - 10% carbamide peroxide (1 hour daily/21 days); CPN - CP incorporated into TiO2; HP - 40% hydrogen peroxide (three 40-minute sessions/7 days apart); HPN - HP incorporated into TiO2. Color shade was evaluated at five different periods (baseline, after 7, 14 and 21 days of bleaching, and 7 days after end of treatment) according to Vita Classical, CIELab and CIEDE2000 scales. Mean particle size (P), polydispersity (PO) and zeta potential (ZP) were evaluated using dynamic light scattering. Data on the different variables were analyzed by mixed model tests for measures repeated in time (ZP e L*), generalized linear models for measures repeated in time (P, PO, Vita Classical and b*), and Friedman and Mann-Whitney tests (a* and color change/ΔE and ΔE00). Results CP and CPN presented higher P, higher PO and lower ZP than HP and HPN (p≤0.05). All groups showed a significant decrease in Vita Classical color scores after 7 days of bleaching (p<0.05), and HPN presented a greater significant reduction than the other groups. L* increased in TiO2 presence, in all groups, without any differences (p>0.05) in bleaching time. A significant reduction occurred in the a* and b* values for all the groups, and HPN presented lower a* and b* values (p<0.05) than CPN. ΔE was clinically noticeable after 7 days, in all groups, and all groups resulted in a perceptible color change according to ΔE00. Conclusion TiO2 did not influence physicochemical properties of the bleaching agents. HPN presented more effective tooth bleaching than CPN.

A novel combination of biallelic ALPL mutations associated with adult hypophosphatasia: A phenotype-genotype association and computational analysis study.

Hypophosphatasia (HPP) is an inherited metabolic disorder that causes defective skeletal and dental mineralization. HPP exhibits a markedly heterogeneous range of clinical manifestations caused by dysfunction of the tissue-nonspecific isozyme of alkaline phosphatase (TNSALP), resulting from loss-of-function mutations in the ALPL gene. HPP has been associated with predominantly missense mutations in ALPL, and a number of compound heterozygous genotypes have been identified. Here, we describe a case of a subject with adult-onset HPP caused by a novel combination of missense mutations p.Gly473Ser and p.Ala487Val, resulting in chronic musculoskeletal pain, myopathy, persistent fatigue, vomiting, and an uncommon dental phenotype of short-rooted permanent teeth. Pedigree and biochemical analysis indicated that severity of symptoms was correlated with levels of residual ALP activity, and co-segregated with the p.Gly473Ser missense mutation. Bioinformatic analysis to predict the structural and functional impact of each of the point mutations in the TNSALP molecule, and its potential contribution to the clinical symptoms, revealed that the affected Gly473 residue is localized in the homodimer interface and predicted to have a dominant negative effect. The affected Ala487 residue was predicted to bind to Tyr479, which is closely located the N-terminal α-helix of TNSALP monomer 2, suggesting that both changes may impair dimer stability and catalytic functions. In conclusion, these findings assist in defining genotype-phenotype associations for HPP, and further define specific sites within the TNSALP molecule potentially related to neuromuscular manifestations in adult HPP, allowing for a better understanding of HPP pathophysiology.

Remineralizing effect of commercial fluoride varnishes on artificial enamel lesions

Abstract: The aim of this study was to evaluate soluble and insoluble fluoride concentrations in commercial varnishes, and their remineralization effect on artificial caries enamel lesions using surface and cross-sectional microhardness evaluations. Forty bovine enamel blocks were separated into four groups (n=10): control (no treatment), Enamelast (Ultradent Products), Duraphat (Colgate-Palmolive) and Clinpro White Varnish (3M ESPE). Surface enamel microhardness evaluations were obtained, artificial enamel caries lesions were developed by dynamic pH-cycling, and the varnishes were then applied every 6 days, after which the enamel blocks were submitted to dynamic remineralization by pH cycles. After removal of the varnishes, the enamel surfaces were reassessed for microhardness. The blocks were sectioned longitudinally, and cross-sectional microhardness measurements were performed at different surface depths (up to 300 μm depth). Polarized light microscopy images (PLMI) were made to analyze subsurface caries lesions. The fluoride concentration in whole (soluble and insoluble fluoride) and centrifuged (soluble fluoride) varnishes was determined using an extraction method with acetone. The data were analyzed to evaluate the surface microhardness, making adjustments for generalized linear models. There was a significant decrease in enamel surface microhardness after performing all the treatments (p<0.0001). Enamelast and Duraphat showed significantly higher enamel microhardness values than the control and the Clinpro groups (p = 0.0002). Microhardness loss percentage was significantly lower for Enamelast (p = 0.071; One-way ANOVA). PLMI showed that subsurface caries lesions were not remineralized with the varnish treatments. No significant differences in the in-depth microhardness levels (p = 0.7536; ANOVA) were observed among the treatments. Enamelast presented higher soluble and insoluble fluoride concentrations than the other varnishes (p < 0.0001; Kruskal-Wallis and Dunn tests). Enamelast and Duraphat varnishes promoted enamel surface remineralization, but no varnish remineralized the subsurface lesion body. Although insoluble and soluble fluoride concentration values did not correspond to those declared by the manufacturer, Enamelast presented higher fluoride concentration than the others.

Mesenchymal stem cells in periodontics: new perspectives / Células mesenquimais indiferenciadas em periodontia: novas perspectivas

ABSTRACT Tissue engineering is a contemporary field of science, which aims to create conditions based on principles of cell and molecular biology, bioengineering and biomaterials to regenerate tissues. Mesenchymal stem cells present high proliferation rates and are able to differentiate into multilineages under certain conditions, suggesting that they have great potential to act in regeneration field. Tooth derived stem cells are a suitable alternative source of mesenchymal cells once they are easily accessible and have poor morbidity to the donor. Studies showed that they have been isolated and characterized from diverse tissues such as dental pulp, exfoliated deciduous teeth, periodontal ligament, gingiva, dental follicle and apical papilla. However studies show that there is heterogeneity among these populations and there is no standard method to select the most appropriate tooth derived stem cells for regenerative procedures. The aim of this review is to present the current perspective of the multiple types of tooth-derived stem cells and to discuss the basis for their use in periodontal tissue engineering.

RESUMO A engenharia de tecidos é um campo contemporâneo da ciência, que visa criar condições baseadas em princípios de biologia celular e molecular, bioengenharia e biomateriais para regenerar tecidos. As células tronco mesenquimais apresentam altas taxas de proliferação e são capazes de se diferenciar, sob certas condições, em multi-linhagens, sugerindo que elas têm grande potencial para atuar no campo da regeneração. As células tronco derivadas de tecidos dentais são uma fonte alternativa adequada de células mesenquimais uma vez que são de fácil acesso e têm baixa morbidade para o doador. Estudos demonstraram que elas já foram isoladas e caracterizadas a partir de diversos tecidos tais como polpa dentária, dentes decíduos esfoliados, ligamento periodontal, gengiva, folículo dental e papila apical. Entretanto, os estudos demonstram que há heterogeneidade entre essas populações e não existe um método padrão para selecionar as células-tronco dentais mais apropriadas para procedimentos regenerativos. O objetivo desta revisão é apresentar o conhecimento atual dos vários tipos de células-tronco derivadas de dentes e discutir as novas perspectivas para seu uso na engenharia de tecidos periodontais.

Computational analysis for GNAQ mutations: New insights on the molecular etiology of Sturge-Weber syndrome.

Somatic activating mutations in the GNAQ have been recently associated with several congenital genetic disorders and tumors; however, the molecular mechanism/etiology that leads to GNAQ somatic mosaic mutation are unknown. Here, we reported a case of Sturge-Weber Syndrome (SWS) manifesting cutaneous vascular malformations (hemifacial Port-wine stain), cerebral and ocular vascular abnormalities (including epilepsy and glaucoma) and harboring a c.548G>A (p.R183Q) somatic mosaic mutation in GNAQ. Computational modeling studies were performed to assistant with the comprehension of the functional impact of p.R183Q and p.Q209L mutations in GNAQ, which encodes a G protein subunit alpha q (Gαq). The p.R183Q mutation was predicted to abolish hydrogen bonds between R183 residue and GDP molecule, destabilizing the inactive GDP-bound conformation of the Gαq mutants. Furthermore, replacement of R183 by Q183 residue was predicted to promote conformation changes in protein surface features affecting the switch I region, a key region that undergoes conformational changes triggered by receptor binding during signal transduction. In addition, replacement of Q209 by L209 residue was predicted to affect the molecular interaction between Gαq and Gß subunit, impairing formation of the inactive heterotrimeric complex. These findings, in association with PPI network analysis, indicate that p.R183Q and p.Q209L mutations result in the over-activation of different downstream effectors, which in turn will determine the distinct cell responses and phenotype. These findings bring new insights on molecular etiology of vascular malformations associated to SWS and on different mechanisms underlying hyperactivation of downstream pathways to Gαq.

Selective COX-2 Inhibitor (Meloxicam) and Tooth-Supporting Bone Quality. A Histomorphometric Study in Rats

Abstract The effects of the non-steroidal anti-inflammatory drugs (NSAIDs) on bone quantity and quality were investigated for years. However, there is lack of information on the impact of NSAIDs on the quality of tooth-supporting alveolar bone in absence of periodontal inflammation. Thus, the aim of this study was to evaluate histometrically the influence of a selective COX-2 NSAID (Meloxicam) on the inter-radicular bone mineral density in rats. Forty-nine adult male Wistar rats were randomly divided into four experimental groups: Subcutaneous injection of 0.9% sterile saline for 15 days (G1; n=12) and 45 days (G2; n=11); and subcutaneous injection of Meloxicam for 15 days (G3; n=13) and 45 days (G4; n=13). Mineral density was histometrically determined in the inter-radicular area of the 1st mandibular molars and data analysis performed by two-way ANOVA (a=5%). Results showed no interaction between time and treatment (p>0.05) and that meloxicam did not affect the alveolar bone density. In contrast, it was found that inter-radicular alveolar bone density increased with time (91.88±3.08% and 92.86±2.38% for groups 15 and 45 days, respectively) (p<0.05). Within the limits of this study, daily administration of a selective COX-2 inhibitor (Meloxicam) did not affect the quality of the inter-radicular alveolar bone in absence of periodontal infection.

Resumo Os efeitos dos fármacos anti-inflamatórios não esteroidais (AINEs) sobre a quantidade e qualidade óssea tem sido investigados ao longo dos anos.Entretanto, há falta de informação sobre o impacto dos AINEs na qualidade do osso alveolar de suporte na ausência de inflamação periodontal. Assim, o objetivo deste estudo foi avaliar, histometricamente, a influência de um AINE seletivo para COX-2 (Meloxicam) na densidade mineral óssea inter-radicular em ratos. Quarenta e nove ratos Wistar, machos e adultos foram divididos aleatoriamente em quatro grupos experimentais: injeções subcutâneas de 0,9% de solução salina estéril por 15 dias (G1, n=12) e 45 dias (G2, n=11); e injeções subcutâneas de Meloxicam por 15 (G3, n=13) e 45 dias (G4, n=13). A densidade mineral foi determinada histometricamente na área inter-radicular dos primeiros molares mandibulares e a análise dos dados realizada por meio de ANOVA (a=5%). Os resultados mostraram nenhuma interação entre tempo e tratamento (p>0,05) e que o meloxicam não afetou a densidade óssea alveolar. Em contraste, foi encontrado que a densidade óssea alveolar inter-radicular aumentou ao longo do tempo (91,88±3,08% e 92,86±2,38% para os grupos 15 e 45 dias, respectivamente) (p<0,05). Dentro dos limites deste estudo, a administração diária de um inibidor seletivo para COX-2 (Meloxicam) não afetou a qualidade do osso alveolar inter-radicular na ausência de infecção periodontal.

Cemento dental: aspectos atuais de interesse para o clínico / Dental cementum: current aspects to the clinicians

Embora tenha havido avanço no entendimento da homeostase do cemento dental, o papel deste tecido e sua biologia permanecem não completamente elucidados. Este estudo buscou fornecer informações sobre os conhecimentos mais recente relacionados à biologia do cemento dental, com o objetivo de discutir o papel exercido por este tecido em condições não fisiológicas nos tecidos periodontais. Devido aos avanços na exploração do tecido ósseo, que compartilha diversas características similares, a pesquisa abrangente sobre o cemento dental tem sido encorajada, a fim de esclarecer a função completa deste tecido na homeostase periodontal e regeneração. Desta forma, no presente trabalho, sempre que possível será feito um paralelo entre osso alveolar e cemento dental. O desenvolvimento de metodologias e técnicas celulares e moleculares avançadas possibilitou um melhor entendimento do comportamento do cemento em situações diversas, como quando em situações patológicas, como a doença periodontal, e até mesmo frente à regeneração tecidual. Ademais, estudos clínicos e em modelo animal demonstraram resultados em relação à formação de cemento em abordagens regenerativas. No entanto, sugere-se que estudos posteriores possam contribuir para um melhor conhecimento sobre o cemento e o perfil celular dos cementoblastos e cementócitos, bem como suas interações para fornecer novos insights para o desenvolvimento de terapias eficientes e mais previsíveis para regeneração dos tecidos periodontais. Apesar dos avanços dos estudos clínicos e laboratoriais, pôde-se concluir que inúmeras questões referentes à biologia do cemento permanecem não esclarecidas.

Although some progress has been made to understand dental cementum homeostasis, its role and biology remains not completely elucidated. This study aimed to provide information on the recent knowledge related to the dental cementum biology, in order to discuss the role of this tissue in physiological and non-physiological conditions in the periodontal tissues. Due to advances in the exploration of bone tissue, which shares several similar features, comprehensive research on dental cementum has been encouraged in order to clarify the complete function of this tissue in periodontal homeostasis and regenerative approach. Novel methodologies and advanced cellular and molecular techniques provided better understanding of cementum in different circumstances, as pathological situations such as periodontal disease and even tissue regeneration. In addition, clinical and animal model designs show positive outcomes to cementum formation in regenerative approaches, however, it is suggested that further studies may contribute to better understand cementum tissue and cementoblasts and cementocytes profile, as well as their interactions, providing new insights to develop efficient and more predictable therapies for periodontal tissue regeneration. Despite advances in clinical and laboratory studies, it can be concluded that many questions regarding the cementum biology remain unclear.

Abordagem integral em odontopediatria: relato de caso clínico / Integral Approach in Pediatric Dentistry: clinical case report

Objetivo: Relatar um caso clínico envolvendo a abordagem cirúrgica/restauradora e medidas preventivas. Relato do caso: Paciente MEMO, 6 anos e 8 meses de idade, feminino, com alto risco/atividade de cárie, apresentando biofilme visível em superfícies lisas livres, lesões de cárie ativa, perda precoce do dente 85, fístula relacionada com a região do dente 75, mudança de cor do dente 61 e perda significativa de dimensão vertical posterior, apresentou-se para tratamento na Clínica de pós-graduação em Odontopediatria da FOP/Unicamp. O plano de tratamento consistiu na abordagem integral focada na promoção da saúde como desfecho principal, ou seja, mudança de comportamento em relação à saúde bucal, e como desfecho secundário, a abordagem cirúrgica/restauradora. Instrução de higiene bucal foi realizada em todas as sessões. O manejo do comportamento foi conduzido por meio da evidenciação e controle de biofilme, profilaxia e adequação do meio bucal seguido da extração do dente 75, selamento de fossas e fissuras dos dentes 36, 46 e 16 e restaurações no 55 e 65. Mantenedor de espaço removível inferior foi realizado. Conclusões: Após seis meses pôde-se observar ausência de biofilme visível, o índice de placa estava controlado e não havia evidência de novas lesões de cárie. Pode-se concluir que o sucesso obtido neste caso destaca a importância da abordagem integral focada na promoção da saúde na clínica odontopediátrica.

Objective: To report a clinic case involving the surgical/restorative approach and preventive actions. Case report: The patient MEMO, aged 6y and 8mo, female, with high caries risk/activity, presenting visible biofilm on free smooth surfaces, active carious lesions, early loss of the 85 tooth, fistula related with the 75 tooth region, color change on 61 tooth and significant loss of posterior vertical dimension has been driven to Pediatric Dentistry Graduate Clinic at FOP/ Unicamp. Treatment plan consisted on integral approach focused as primary outcome on health promotion, behavior change in relation to oral health, and as secondary outcome, the surgical/ restorative approach. Oral hygiene instruction was conducted in all sessions. The behavior management was conducted by evidence and control of visible dental plaque, prophylaxis and oral environment adequation; extraction of 75 tooth, pit and fissure sealing of the 36, 46, 16 teeth, and restorations in the 55 and 65. Removable lower space maintainer appliance was made. Conclusions: After 6 months it could be observed that there was not visible biofilm, the IP was controlled. In addition, there was no evidence of new caries lesions. It could be concluded that the success obtained on this clinical case bring about the importance of the integral performance focused on healthy promotion in pediatric dentist clinic.

A clinical report of functional and esthetic oral rehabilitation in a high-caries-risk child: one-year follow-up / Caso clínico de reabilitação oral estética e funcional em criança de alto risco à cárie: um ano de acompanhamento

Este caso discutiu a abordagem multidisciplinar da reabilitação oral estética e funcional de uma criança com alto risco à cárie com perda prematurade dentes decíduos devido a complicações do tratamento endodôntico associado a cárie dentária generalizada. O paciente foi diagnosticado com mordida aberta anterior e deglutição atípica. O mesmo apresentou ansiedade e baixa auto-estima devido ao comprometimento estético. Combinação de procedimentos clínicos direcionados, com ênfase e foco no cuidado bucal domiciliar e o envolvimento ativo dos pais fez parte do processo de tratamento integral do paciente. Este foi examinado mensalmente por um odontopediatria, o qual orientou sobre hábitos alimentares, exposição a fluoretos, presença de biofilme, prevalência de cárie e má oclusão. Evidente melhora foi observada na função mastigatória,estética facial e comportamento psicológico aos 12 meses de acompanhamento clínico do caso.

This case discusses a multi-disciplinary approach to oral functional and esthetic rehabilitation on a high-caries-risk child with prematurely lost primary teeth due to endodontic complications associatedwith wide-spread dental caries. The patient was diagnosed with an anterior open bite and atypical swallowing. He exhibited anxiety and low selfesteemdue to esthetic impairment. A combination of targeted clinical procedures, a focus on oral home care and active parental involvement was integral to the treatment process. The patient was examined monthly by a pediatric dentist regarding dietary habits, fluoride exposure, biofilm= presence, caries prevalence, and malocclusion. Improvement was evident in patient’s masticatory function, facial esthetics, and psychological behavior at a 12-month follow-up evaluation.

Permeability and smear layer removal: effects of different chemical agents on the primary root dentin.

PURPOSE: The purpose of this study was to evaluate the effects of chemical agents on the permeability and removal of the smear layer in the primary root dentin. METHODS: Fifty roots were distributed into 6 groups: (1) 5.25% sodium hypochlorite (SH); (2) 5.25% SH+17% ethylenedia-minetetraacetic acid (SHE); (3) 2% chlorhexidine (CHX); (4) 2% CHX+17% ethylenediaminetetraacetic acid (CHXE); (5) 17% EDTA (E); and (6) saline solution (SS). The canals were instrumented and irrigated. The roots were dyed, washed, and sectioned, and the permeability index was measured. The amount of smear layer was scored. Data were submitted to analysis of variance, Kruskal-Wallis, Student-Newman-Keuls and t tests (P<.05). RESULTS: Significant differences were observed in the cervical and apical thirds for the CHX (P=.03), CHXE (P=.027), SS (P=.038), and SH (P<.001) groups. The SS group showed a heavy smear layer in all thirds. Root canals treated with SHE showed great cleaning in the cervical, middle, and apical thirds. CONCLUSION: Sodium hypochlorite associated with ethylenediaminetetraacetic acid produces the best root canal cleaning and the highest permeability in all thirds.

Influence of environmental conditions on properties of ionomeric and resin sealant materials

OBJECTIVES: The aim of this study was to determine the effect of environmental conditions on the degradation of ionomeric and resin sealant materials. MATERIAL AND METHODS: FluroShield, Vitremer, and Ketac Molar disc-shaped specimens (n=18/material) were prepared, polished, subjected to initial hardness and roughness readings. Six discs of each material were randomly assigned to one of three different storage solutions: 0.3 percent citric acid (CA), demineralization solution (DE), and remineralization solution (RE). The specimens were individually immersed in 3 mL of the test solutions, which were daily changed. After 15 days of storage, new surface roughness and hardness readings were done. Fluoride release in the solutions was measured within 15 days. Data were analyzed by ANOVA and Tukey's and Contrast tests (á=0.05). RESULTS: The storage in CA increased the roughness of Vitremer and Ketac Molar. A significant reduction in hardness was observed for all materials after storage in all solutions. For all materials, the greatest amounts of fluoride release occurred during the 1st day. FluroShield presented the same patterns of fluoride release in all solutions. Ketac Molar and Vitremer released the highest amounts of fluoride in the CA solution. CONCLUSIONS: Ionomeric materials are more susceptible to degradation than resin-based materials under acidic conditions. Acidic conditions lead to a higher fluoride release from ionomeric materials.

Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials

This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm² area). G1 and G3 were sterilized with a 14.5 KGy dose at 27ºC for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (α=5 percent). Gamma sterilization decreased the fluoride release of FS by approximately 50 percent, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials.

Este estudo avaliou o efeito da esterilização com raios-gama na liberação de flúor e atividade antibacteriana de materiais resinosos, Fluroshield (FS) e Clearfil Protect Bond (CPB). Quatro grupos foram formados: G1-FS e gama; G2-FS sem gama; G3-CPB e gama; G4-CPB sem gama. Doze discos de cada material foram preparados para análise de liberação de flúor, os quais foram cobertos com esmalte de unha, exceto em um lado com 50,4 mm² de área. G1 e G3 foram esterilizados com dose de 14,5 KGy por 24 h/27ºC, enquanto G2 e G4 (controles) não foram esterilizados e foram mantidos sob as mesmas condições de tempo e temperatura. As leituras de liberação de flúor foram feitas em duplicata (n=6) por um eletrodo específico. A atividade antibacteriana foi avaliada pelo teste de difusão em agar. Os halos de inibição foram medidos após 48 h. Os dados foram analisados pelos testes ANOVA e Tukey (α=5 por cento). A esterilização gama diminuiu a liberação de flúor de FS em cerca de 50 por cento, enquanto CPB não foi afetado. Não houve diferença estatisticamente significante entre os grupos esterilizados e controle no efeito antibacteriano do CPB. FS não apresentou atividade antibacteriana. A esterilização gama diminuiu a liberação de flúor de FS, mas não afetou a atividade antibacteriana dos materiais estudados.

Diagnóstico e estratégiasde tratamento de um dente supranumerário e suas implicações para a oclusão: relato de caso clínico / Impact of sodium hipoclorite and EDTA on the qality sealing of composite resin restoration performed in human dentin

A prevalência de dentes supranumerários na população em geral varia entre 1 e 3%. Devido a essa frequência, o cirurgião-dentista e o especialista devem conhecer os sinais patognomônicos da presença de um supranumerário, assim como o tratamento apropriado. A etiologia dessa anomalia ainda não está totalmente entendida, apesar de a proliferação da lâmina dentária ou fatores genéricos estarem envolvidos. Os dentes supranumerários podem causar atraso ou erupção ectópica dos dentes permanentes, podendo alterar tanto a oclusão quanto a estética facial do indivíduo. Nesse sentido, o diagnóstico precoce do dente supranumerário em desenvolvimento torna-se importante para se aperfeiçoar e minimizar o tratamento necessário, reduzindo a extensão da cirurgia e o tempo de tratamento ortodôntico, bem como suas possíveis complicações. O objetivo do presente artigo foi descrever o tratamento adequado de um dente supranumerário superior e o início da intervenção necessária para o alcance da normoclusão, saúde periodontal, estética favorável e estabilidade do tratamento

Insucesso de reimplante dentário após avulsão traumática: relato de caso clínico(AU) / Tooth replantation failure after traumatic avulsion: a case report

Traumatismo dentário são comuns na população. Dentre esses, as avulsões dentárias variam de um a 16% sendo os incisivos centrais superiores permanentes os dentes mais envolvidos. O sucesso da técnica de reimplante dentário depende do período em que o dente permaneceu fora do alvéolo e do meio de conservação do mesmo. Quanto maior o período extra-alvéolo menores são as chances de sucesso da terapêutica. O prognóstico para dentes reimplantados pode ser favorável desde que a indicação e o tratamento sejam realizados de forma adequada. Esse artigo relata e discute o insucesso de um caso clínico de reimplante dentário após avulsão traumática, o qual não foi tratado endodonticamente e acompanhado, com conseqüente reabsorção radicular externa, resultando na exodontia do elemento dentário. Concluiu-se que o sucesso do tratamento depende da realização do diagnóstico preciso e da terapêutica adequada.

Is the presence of the smear layer a limiting factor for root dentin permeability in primary teeth?

PURPOSE: The purpose of this study was to correlate the dye permeability to the morphological aspect (presence or absence of a smear layer) of the primary root dentin wall, using scanning electron microscopy, regarding the endodontic preparation and irrigation methods. The hypothesis evaluated was that there was a correlation between the dye permeability and the morphological aspect of the primary root dentin. METHODS: A total of 112 extracted primary roots were distributed into the following groups: Dakin's liquid, Dakin+hydrogen peroxide; 2% chlorhexidine gel; and saline solution. Manual (MI) or Ultrasonic irrigation (UI) was performed. The roots were made impermeable, filled with dye (2% methylene blue), and longitudinally sectioned. The halves were divided in cervical, middle, and apical thirds for dye penetration measurement. The samples were observed under a scanning electron microscope. The data were submitted to linear regression analysis with a dummy variable (P<.05). RESULTS: The data revealed a relationship between decreasing permeability and the presence of a smear layer on root canal dentin walls for MI in the middle third (P=.0147). Regarding UI, no statistically significant relation was observed (P>.05). CONCLUSIONS: The presence of a smear layer on root canal dentin walls was not a limiting factor to dye penetration in all groups except the middle third for manual irrigation.

Effect of cleansers and irrigation methods on primary root dentin permeability.

PURPOSE: The purpose of this study was to evaluate the effects of cleansers and irrigation methods on the permeability index (PI) in primary root dentin. METHODS: One hundred twelve teeth were extracted and sectioned transversely, discarding their crowns. Then, the roots were distributed according to the cleansers: (1) Dakin (D); (2) Dakin+hydrogen peroxide (DHP); (3) 2% chlorhexidine gel (C); and (4) saline (S). The canals were manually instrumented. Irrigation was performed manually (MI) or ultrasonically (UI). The roots were: (1) made impermeable; (2) filled with 2% methylene blue solution; and (3) longitudinally sectioned. The halves were marked in thirds (cervical, middle, and apical), and the areas of dye penetration were measured. PI data were submitted to factorial analysis of variance and Tukey tests (P<.05). RESULTS: A significant effect of MI/UI, in association with cleansers, was seen on PI. For all thirds, the PI of MI was superior to UI. In the cervical third, MI achieved a high PI when associated with D, DHP, and S. UI associated with S and C produced the highest PI. In the middle third, MI associated with D and DHP produced the highest PI. In the apical third, MI associated with D demonstrated the highest PI. None of the UI and cleanser associations induced differences in PI for the middle and apical thirds. CONCLUSION: MI produced better results than the UI. The D, DHP, and S cleansers demonstrated the highest PIs, suggesting that the combination of MI and these cleansers is recommended for primary teeth to maintain dentin permeability.