Influence of bioactive particles and onium salt on the physicochemical properties of experimental infiltrants

Abstract This study evaluated physicochemical properties of experimental infiltrants after addition of hydroxyapatite nanoparticles (HAp) or 58S bioactive glass (BAG) and diphenyliodonium hexafluorophosphate (DPI). The resin matrix was composed of TEGDMA/Bis-EMA (3:1), 0.5 mol% CQ, and 1 mol% EDAB. The blends received or not 0.5 mol% DPI and 10% wt BAG or HAp. Icon was used as commercial control. The groups were characterized by XRD, FT-IR spectrometry, and SEM before and after simulated body fluid (SBF) immersion for up to 7 days. Polymerization kinetics (n =3 ), water sorption and solubility (n=10), and viscosity (n = 3) were surveyed. For polymerization kinetics, the samples were polymerized for 5 min and the data were obtained from 40 s and 5 min. Statistical analysis was made using ANOVA and Tukey's test (a = 0.05). After 7 days of SBF immersion, XRD and FT-IR showed that the HAp crystalline phase was present only in the HAp groups. A lower degree of conversion (DC) and polymerization rate were observed for the Icon and BAG groups, whereas HAp showed higher values. For the BAG group, DPI increased polymerization rate and DC in 40 s. After 5 min, all groups presented DC above 80%. In groups with particles, the HAp groups exhibited higher viscosity, whereas DPI groups showed a decrease in viscosity. Icon had the highest water sorption. To conclude, BAG neither improved the physicochemical properties studied, nor did it show bioactive properties. The addition of DPI reduced viscosity caused by particle addition and also attenuated the DC decrease caused by BAG addition. The addition of bioactive particles to infiltrants should be seen with caution because they increase viscosity and may not bring major clinical improvements that justify their use. DPI might be indicated only if any component is added to the infiltrant to act as a compensation mechanism.

Can composition and preheating improve infiltrant characteristics and penetrability in demineralized enamel?

Abstract The composition of infiltrants can influence their physical properties, viscosity and depth of penetration (DP). Strategies are used to increase the DP, such as the addition of diluents or the use of heat. This study aimed to evaluate the effect of preheating and composition on physical properties and DP of infiltrants in demineralized enamel. The groups were assigned, and the following experimental formulations were made: 25%BisEMA +75%TEGDMA; 25%BisEMA +65%TEGDMA +10%ethanol; 25%BisEMA +65%TEGDMA +10%HEMA; 100%TEGDMA; 90%TEGDMA +10%ethanol; 90%TEGDMA +10%HEMA. The samples were photoactivated at two temperatures (25°C and 55°C). Degree of conversion (DC) was performed using an infrared spectrophotometer. Elastic modulus (E), flexural strength (FS) and contact angle (CA) tests were also performed. The DP of an infiltrant in demineralized enamel was determined by confocal laser scanning microscopy (CLSM) using an indirect labeling technique. The data were analyzed by two-way ANOVA and Tukey's test. DC increased after preheating in all the groups; however, 90%TEGDMA+10%ethanol showed the lowest DC for both temperatures, and the lowest E. Preheating did not influence E or FS. The CA increased at 55°C for most groups, but decreased for groups containing HEMA. Temperature did not seem to influence DP, and Icon showed the lowest DP values. The 100%TEGDMA composition showed more homogeneous penetration, whereas Icon showed heterogeneous and superficial penetration. The preheating technique does not improve all properties in all the material compositions. The composition of a material can influence and improve its properties.

Effect of diphenyliodonium hexafluorphosphate in the yellowing and properties of experimental resin cements

Aim: The yellowing effect is undesirable and can occur in the dental restoration margins when light-cured resin cements containing camphorquinone as photoinitiator is used. This study aimed to evaluate the effect of diphenyliodonium hexafluorphosphate (DPI) in photoinitiator systems that contained different concentrations of camphorquinone (CQ) and dimethylamino ethyl benzoate (EDAB) on resin cements. Methods: A base (1:1) of bisphenol A diglycidyl methacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) was obtained, and 60wt% of glass fillers was added. Eight formulations were obtained: RC1 (0.5mol% CQ / 1mol% EDAB), RC2 (0.5mol% CQ / 2mol% EDAB), RC3 (1mol% CQ / 1mol% EDAB), RC4 (1mol% CQ / 2mol% EDAB), and RC5 to RC8, which contained the same bases plus 0.5mol% DPI. Experimental resin cements were evaluated by the degree of conversion (DC), L*a*b* color analysis, water sorption (WS) and solubility (S), flexural strength, and Elastic Modulus. The data were analyzed by three-way ANOVA, Tukey's and Mann-Whitney tests (α = 0.05). Results: The combination of DPI and 0.5mol% CQ increased DC in RC6 and L* in RC5 without increasing the WS and a* b* values. CQ at 1mol% showed higher values of b* and lower values of a*, except for RC3. Groups with 2mol% EDAB showed higher DC. Conclusion: The addition of DPI reduces CQ, generating a decreased yellowing effect, while maintaining adequate properties in the resin cements, especially with 2mol% EDAB

Avaliação radiográfica da presença de bolhas em restaurações classe II in vitro utilizando diferentes técnicas restauradoras / Radiographic evaluation of the presence of voids in class II in vitro restaurations using different restorative techiniques

Introdução: a presença de bolhas no interior das restaurações de resina composta pode reduzir suas propriedades biomecânicas, levando ao insucesso do tratamento. Objetivo: avaliar visual e radiograficamente a presença de bolhas em restaurações de resina composta classe II in vitro utilizando diferentes técnicas restauradoras. Metodologia: foram confeccionados 40 corpos de prova em uma matriz metálica bipartida, randomizados em quatro grupos (n=10) de acordo com a técnica de inserção de resina utilizada: Grupo 1 - resina bulk fill flow e resina regular, Grupo 2 ­ resina bulk fill regular e resina regular, Grupo 3 - resina regular pela técnica incremental oblíqua e Grupo 4 ­ resina regular pela técnica incremental horizontal. A avaliação da presença de bolhas foi realizada pelos testes visual e radiográfico. Resultados: o grupo da resina bulk fill flow (G1) foi o que apresentou menor média de bolhas para os dois métodos de avaliação (6,5 para o visual e 2,4 para o radiográfico) e o grupo da técnica incremental horizontal foi o que apresentou maior média de bolhas (24,2 para o teste visual e 4,5 para o radiográfico). Conclusão: a técnica bulk fill apresentou menor formação de bolhas quando comparada à técnica incremental. Desta forma, as resinas bulk fill, principalmente com sua apresentação fluida, parecem ser uma opção viável de material restaurador direto por ser de inserção única, simplificando o procedimento, e evitar a incorporação de bolhas, preservando as propriedades biomecânicas do material.

Introduction: the presence of voids within the composite resin restorations can reduce their biomechanical properties, leading to the failure of the treatment. Objetictive: to evaluate visual and radiographically the presence of voids in class II in vitro composite resin restorations using different restorative techniques. Methodology: 40 specimens were made in a bipartite metal matrix, randomized into four groups (n = 10) according to the used resin insertion technique: Group 1 - Bulk Fill Flow Resin and Regular Resin, Group 2 ­Bulk Fill Regular Resin and Regular Resin, Group 3 - Regular Resin by oblique incremental technique and Group 4 ­Regular Resin by incremental horizontal technique. The evaluation of the presence of voids was made by visual and radiographic tests. Results: the Bulk Fill Flow Resin group (G1) was that showed lower average of voids for the two evaluation methods (6,5 for the visual test and 2,4 for the radiographic) and the group of horizontal incremental technique was the one that presented higher average of voids (24,2 for the visual test and 4,5 for the radiographic). Conclusion: the Bulk Fill technique showed lower formation of voids compared to incremental technique. This way, the Bulk Fill resins, mainly with their fluid presentation, appear to be a viable option of direct restorative material for being single insertion, simplifying the procedure and preventing the incorporation of air voids, preserving the properties the biomechanical material.

Mass change of a sodium bicarbonate air-polished nanocomposite exposed to cigarette smoke, coffee, and red wine / Perda de massa de nanocompósito jateado com bicarbonato de sódio e exposto à fumaça de cigarro, café e vinho tinto

Introdução: As resinas compostas estão sujeitas à desafios na cavidade oral relacionados aos hábitos dos pacientes, que podem comprometer a integridade e longevidade das restaurações. As consequências da associação do consumo de bebidas e o uso de cigarros à profilaxia profissional precisam ser estudadas. Objetivo: O objetivo desse estudo foi avaliar como o jateamento com bicarbonato de sódio afeta a mudança de massa (sorção e solubilidade) de uma resina composta exposta à fumaça de cigarro, vinho tinto e café. Material e método: Oitenta corpos-de-prova de resina composta (FiltekZ350 XT - 3M/ESPE) foram preparados e distribuídos em 8 grupos (n=10): G1 (jateamento + água destilada), G2 (jateamento + café), G3 (jateamento + vinho tinto), G4 (jateamento + fumaça de cigarro), G5 (água destilada), G6 (café), G7 (vinho tinto) e G8 (fumaça de cigarro). Os corpos-de-prova de resina composta foram pesados em três tempos diferentes para obter M1 (massa inicial), M2 (massa após 30 dias de armazenamento nas soluções testadas e exposição ao agente) e M3 (após dessecação). Os valores de sorção e solubilidade foram calculados e analisados usando ANOVA 2-fatores e teste Tukey (5%). Resultado: Os grupos experimentais tiveram maior sorção e solubilidade comparado ao grupo controle, independentemente do uso do jateamento. Não houve diferença estatística na sorção para o fator jateamento. Porém, a solubilidade foi maior nos grupos jateados. Conclusão: O jateamento com bicarbonato de sódio foi capaz de intensificar a solubilidade da resina testada, embora não tenha aumentado significativamente os valores de sorção.

Introduction: Composite resins are subject to challenges in the oral cavity that are related to patients' habits, which can compromise the restorations' integrity and longevity. Therefore, it is necessary to study how consuming beverages and smoking cigarettes affects professional prophylaxis. Objective: The aim of this study was to evaluate how the sodium bicarbonate air-polishing affects the mass change (sorption and solubility) of a composite resin exposed to cigarette smoke, red wine, or coffee solution. Material and method: Eighty composite resin samples (FiltekZ350 XT - 3M/ESPE) were prepared and distributed into 8 groups (n=10): G1 (air-polishing + distilled water), G2 (air-polishing + coffee), G3 (air-polishing + red wine), G4 (air-polishing + cigarette smoke), G5 (distilled water), G6 (coffee), G7 (red wine), or G8 (cigarette smoke). The composite resin samples were weighed in triplicate to obtain M1 (initial mass), M2 (mass after 30 days of storage in the tested solutions), and M3 (after desiccation) values. The sorption and solubility values were calculated and analyzed using 2-way ANOVA and Tukey's test (5%). Result: The experimental groups had higher sorption and solubility values than the control groups, regardless of whether air-polishing was used. There was no statistically significant difference in the sorption between the air-polished and non-air-polished groups; however, the solubility was higher in the air-polished groups. Conclusion: Air-polishing using sodium bicarbonate powder was able to intensify the solubility process of the tested resins but did not significantly increase the sorption values.

Treatment of non-carious lesions: diagnosis, restorative materials and techniques

Management of non-carious cervical lesions (NCCLs) still is a challenge in clinical practice. The diagnosis is the key to treat these lesions successfully. Aim/Case report: Therefore, the aim of this case report is to describe the diagnosis and treatment of generalized abfraction lesions associated to abrasion lesions of a 43 years old patient and to discuss considerations about the technique and materials to be used appropriately. After the diagnosis, a treatment plan with preventive and restorative approach was elaborated. The occlusal adjustment was performed to distribute the contact points and the patient was instructed in relation to tooth brushing habits. It was also recommended that the patient use a dentifrice with potassium nitrate for the control of sensitivity. For lesions over 1mm deep, the restorative treatment was performed using the self-etching adhesive system and nanohybrid composite by the stratification technique. Unsatisfactory restorations have been replaced. Occlusal splint was done and the patient was instructed to use the device every day overnight. One year after treatment, follow-up was performed. The appearance of new NCCLs was not observed. There was no progression of lesions smaller than 1 mm. There was no loss of restorations. All restorations were fully satisfactory and the patient reported absence of dentin hypersensitivity. Conclusion: The treatment performed besides being aesthetically satisfactory after 1 year resulted in the control of the disease, preventing the appearance of new lesions and guaranteeing a better quality of life to the patient

Effect of air-polishing on properties of nanocomposite submitted to coffee, red wine and cigarette smoke

AIM: The aim of this study was to evaluate the surface roughness and the color stability of nanocomposite exposed to the sodium bicarbonate air-polishing (SBAP) followed by red wine, coffee and cigarette smoke exposure. MATERIALS AND METHODS: 64 nanocomposite specimens were prepared and allocated in 8 groups: G1 (SBAP + distilled water), G2 (SBAP + coffee), G3 (SBAP + red wine), G4 (SBAP + cigarette smoke), G5 (distilled water), G6 (coffee), G7 (red wine) and G8 (cigarette smoke). The surface roughness was evaluated in three periods: before and after SBAP and after exposuring to agents tested. The color was evaluated according to CIEL*a*b* parameters using reflection spectrophotometer in two moments: initial and 30 days after the exposure to staining agents. Data were subjected to three-way repeated measures ANOVA and Tukey's test (5%). RESULTS: The results showed a higher surface roughness of the nanocomposite submitted only to the SBAP and those exposed to the SBAP followed by exposure to the coffee or wine solution. The previous application of SBAP followed by cigarette smoke exposure did not increase the roughness of nanocomposite. The SBAP procedure just increased the staining for cigarette smoke group. CONCLUSION: The SBAP increases resin surface roughness, which worsens when there is exposure to coffee and red wine solution. In addition, SBAP may also provide increased staining of nanocomposites exposed to cigarette smoke

Experiência da família rural ao ter o pai/esposo com câncer de próstata / Experience of rural families when having a father/husband with prostate cancer

Objetivo: relatar a experiência da família rural ao ter o pai/esposo frente ao adoecimento por câncer de próstata. Métodos: pesquisa qualitativa, realizada na residência de quatro famílias rurais com nove sujeitos. Utilizou-se a entrevista semiestruturada, e pela análise dos dados, foram estabelecidas categorias temáticas. Resultados: os homens com câncer tinham idades entre 66 e 68 anos, conheciam o diagnóstico no máximo há quatro anos. Os familiares respondentes foram esposas ou filhos, com idades entre 30 e 69 anos. As famílias se dedicavam à agricultura e pecuária. A categoria nominada A neoplasia de próstata na nossa vida é formada pelas subcategorias: descoberta do diagnóstico; apoio familiar; mudanças decorrentes do adoecimento e dificuldades enfrentadas durante o tratamento. Conclusão: a experiência da família rural é permeada pela constante divisão de tarefas entre os cuidados ao pai/esposo e as atividades laborais, mudanças na vida conjugal, tristezas, angústias e esperanças sobre um futuro incerto.