Surface smoothness of resin composites after polishing-A systematic review and network meta-analysis of in vitro studies.

A systematic review and network meta-analysis was performed to provide evidence for the best polishing protocol for different types of resin composites to minimize surface roughness. A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, EMBASE, and Cochrane Library on July 2, 2019 (updated in December, 2020). In vitro studies that included at least two systems for polishing resin composites and analyzed surface roughness were included. The risk of bias was evaluated. A random-effects Bayesian-mixed treatment comparison model was used to compare surface roughness in resin composites with the different types of polishers. Surface under the cumulative ranking curve (SUCRA) analysis was performed to rank the probability for the best polishing system. After removal of duplicates, title and abstract screening yielded 34 studies. Network meta-analysis was not possible for hybrid and microhybrid composites. SUCRA analysis showed that abrasive paper discs allowed greater surface smoothness for nanohybrid and nanofill composites to a probability of between 83% and 91.6%. Silicon carbide brush had a 78.2% probability of being the best system for microfill composites. The use of abrasive paper disc polishers showed a favorable result in nanofill and nanohybrid resin composites. Silicon carbide brush has a greater chance of promoting a smoother surface for microfill resin composites.

Influence of knowledge on Brazilian student's perception of life and clinical classes during COVID-19.

BACKGROUND: The current pandemic associated with SARS-CoV-2 has negatively influenced several activities, including teaching in Operative Dentistry. The aim of this study was to evaluate the influence of knowledge in Operative Dentistry on undergraduate students' perception related to personal life and return to clinical practices classes during pandemic. MATERIALS AND METHODS: The present research was a cross-sectional, observational, and qualitative survey. The 16-item based questionnaire was sent to undergraduate students in 2020, which were divided into two groups, according to the Operative Dentistry knowledge: G1-not started clinical practice; G2-already started or completed clinical practice. Questions were focused on the impact of the pandemic in relation to their personal lives and return to clinical practice classes. Chi-square association test was performed using the SigmaPlot 12.0 software (P ≤ 0.05). RESULTS: The response rate was 55.5% for G1 and 44.4% for G2. Regarding the questions related to personal life, G1 demonstrated higher percentages of fear of contracting the virus during theoretical classes. Same observations were found when students answered about their fear of contracting coronavirus during the clinical practice classes. However, G2 presented the highest agreement responses for the preparedness feeling to return to theoretical classroom, clinical practice classes, and the possibility of applying online learning. CONCLUSIONS: In general, students' knowledge had little influence on perception of personal life. However, students who have more knowledge in operative dentistry presented more security about returning to clinical classes.

Color and surface gloss stability of bis-acryl and resin composite after exposure to cigarette smoke / Estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas após exposição por fumaça de cigarro

Objective: To evaluate color and surface gloss stability of bis-acryl resins and resin composites, submitted to artificial staining with cigarette smoke. Material and Methods: Specimens of each material were prepared (n=15). Two resin composites (GrandioSO [RCG], Filtek Supreme [RCZ]) and five bis-acryl resins (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] and Yprov [BisYPR]) were tested. Initial color was assessed using a spectrophotometer and surface gloss with a glossmeter. Samples were submitted to smoke exposure (10 cigarettes under 8 minutes per cycle). After 3 and 6 cycles, color and gloss were reassessed. Final readings were performed after brush prophylaxis. Data were analyzed using two-way repeated ANOVA and Tukey's test (p<0.05). Results: Differences and interaction of factors (p<0.01) were detected for both color and gloss readings. Resin composites were the least affected by aging, with gloss reduction after prophylaxis. Differences were detected among bis-acryl resins, with better results for BisLUX and BisPRO. BisPRO and BisSTR, showed reduction in gloss after 60 cigarettes, while BisYPR gloss decreased at all evaluated periods. Conclusion: Resin composites are less susceptible to changes after smoke exposure, while bis-acryl resins results are brand-dependent. Prophylaxis negatively influenced the surface gloss of most of the tested materials (AU)

Objetivo: Avaliar a estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas, submetidos ao manchamento artificial por fumaça de cigarro. Material e Métodos: Foram preparados espécimes de cada material (n=15). Duas resinas compostas (GrandioSO [RCG], Filtek Supreme [RCZ]) e cinco resinas bisacrílicas (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] e Yprov [BisYPR]) foram testados. A cor inicial foi avaliada usando um espectrofotômetro e o brilho de superfície com um medidor de brilho. As amostras foram submetidas à exposição de fumaça de cigarro (10 cigarros com até 8 minutos por ciclo). Após 3 e 6 ciclos, a cor e o brilho foram reavaliados. As leituras finais foram realizadas após a profilaxia escova de robinson. Os dados foram analisados usando de medidas repetidas e teste de Tukey (p<0,05). Resultados: Foram detectadas diferenças e interação de fatores (p<0,01) tanto para leituras de cor quanto para leituras de brilho. As resinas compostas foram as menos afetados pelo envelhecimento, com redução do brilho após a profilaxia. Foram detectadas diferenças entre as resinas bisacrílicas, com melhores resultados para BisLUX e BisPRO. BisPRO e BisSTR, mostraram redução de brilho após 60 cigarros, enquanto que o brilho da BisYPR diminuiu em todos os períodos avaliados. Conclusão: As resinas compostas são as menos suscetíveis a mudanças após a exposição à fumaça, enquanto os resultados das resinas bisacrílicas são dependentes da marca. A profilaxia influenciou negativamente o brilho de superfície da maioria dos materiais testados.(AU)

Conservative approach to treating severe tetracycline staining: a 12-month follow-up.

Severe tetracycline staining may affect the esthetics of teeth and the self-esteem of patients. This case report describes minimally invasive treatment with dental bleaching and direct restorations to improve the esthetics of tetracycline-stained teeth in a 44-year-old woman. All of the patient's teeth were affected by grayish brown staining, and the maxillary central incisors demonstrated incisal wear. The buccal angulation of the anterior teeth and the patient's Class II skeletal profile hindered the use of direct or indirect veneer restorations. The proposed treatment was home bleaching with 10% carbamide peroxide applied in a soft vinyl tray, which was worn overnight for the first 3 months and 2 hours daily for the next 3 months (total treatment time of 6 months). Afterward, a single session of in-office bleaching with 37% hydrogen peroxide was performed over resistant bands of staining observed at the cervical thirds of the teeth. Fourteen days after the in-office bleaching treatment, composite resin restorations were placed at the incisal areas of the maxillary central incisors and the cervical areas of the central incisors, lateral incisors, and canines to treat the incisal wear and mask the remaining dental discoloration. In some cases, minimally invasive treatment with tooth bleaching might be indicated for the esthetic treatment of teeth severely stained by tetracycline, although this approach presents limitations. In the present case, the patient was satisfied with her smile after the treatment protocol was completed, and the results remained stable after 12 months. The patient reported an improved quality of life after treatment.

Resolução estética de lesões de mancha branca pós-tratamento ortodôntico / Esthetic resolution of white spot lesions after orthodontic treatment

O objetivo deste estudo foi comparar as técnicas de microabrasão de esmalte (ME) e infiltração de resina (IR) em relação à resolução estética de lesões cariosas de mancha branca (LCMB) e avaliar a correlação entre a luminosidade das lesões quando transiluminadas e a resolução do problema (estudo 1); avaliar em um estudo "in vitro", a eficácia do clareamento dental, em amostras de dentes submetidos previamente a IR (estudo 2); avaliar a efetividade do clareamento dental 12 meses após a realização dos protocolos de mínima intervenção, em um estudo de série de casos (estudo 3). Para o estudo 1 foram selecionados 17 pacientes que foram divididos em 2 grupos: ME (N=8) e IR (N=9). Um dente de cada paciente foi fotografado sob condição normal e do mesmo dente com auxilio de dispositivo translume. Em seguida os pacientes foram submetidos às técnicas de mínima intervenção. Após 7 dias de acompanhamento, o mesmo protocolo fotográfico foi realizado. Para resolução estética, foi delimitado a área do dente em relação a área da mancha por software. Para avaliação da cor da mancha quando evidenciada, os valores de luminosidade (L*) das coordenadas L*a*b* foram avaliados antes e após a intervenção, sendo mensurados valores das áreas sadias e área da mancha mais enegrecida. Os dados de correlação foram submetidos ao teste de Person. A resolutividade dos tratamentos foi dada por um Teste t-Student e a diferença de luminosidade antes e após os tratamentos foi dado pelo teste Anova 2 fatores de medidas repetidas (p<0,05). Para o estudo 2, quarenta superfícies de esmalte bovino foram submetidas à desmineralização. Após, foram estabelecidos dois protocolos de manchamento. Vinte espécimes foram imersos em caldo de manchamento por 24 horas (Lab 1) ou 7 dias (Lab 2). Dez corpos-de-prova de cada grupo receberam a aplicação de IR. Todas as amostras foram clareadas com gel de peróxido de carbamida 15% por 14 dias (8 horas diárias). A mensuração da cor foi realizada em espectrofotômetro de refletância em três momentos: inicial, após o manchamento e após o clareamento. Os dados (CIEDE00) foram analisados pelo teste t-Student (p <0,05). Para o estudo 3, foram selecionados 4 voluntários, que tinham LCMB nos dentes anteriores superiores. Os pacientes foram divididos de forma aleatória em dois grupos, sendo estes: ME e IR na área de mancha. Para resolução estética das LCMB, foi determinada a área da mancha em relação a área do dente e a porcentagem da redução pós protocolos. Após 12 meses de acompanhamento, os pacientes receberam clareamento dental, com peróxido de carbamida 10%, durante 21 dias. Os dados do estudo 1 mostram que não houve correlação entre as áreas da mancha (normal e transiluminada) e a resolução estética das mesmas (p>0.05). Em relação a resolutividade, não houve diferença entre os tratamentos (p=0.403). O valor de Luminosidade aumentou após a realização dos procedimentos (p=0.001). Para o estudo 2, nenhuma diferença significativa foi observada no Lab 1 (p=0,560). Para o Lab 2, foram detectadas diferenças significativas (p=0,031). Uma vez que o clareamento foi mais efetivo no grupo não submetido a IR (Lab2). Os resultados do estudo 3 mostram que ambos os protocolos reduziram e/ou suavizaram as áreas das manchas. Após 12 meses de acompanhamento, a técnica de ME apresentou redução no valor da área de mancha. Por fim, o clareamento dental foi efetivo em ambos os protocolos, sem diferenças entre as técnicas. Frente as metodologias propostas, pode-se concluir que: não houve diferenças entre os tratamentos em relação a remoção ou mascaramento das LCMB; a cor das manchas quando transiluminadas não estão relacionadas a resolução estética das mesmas; "in vitro", dentes fortemente manchados, submetidos ao tratamento com RI, o produto parece se comportar como uma barreira semipermeável à penetração do peróxido. Por fim, ambas as técnicas podem ser indicadas para reduzir ou suavizar as áreas de mancha. A ME apresentou redução das áreas de mancha no período avaliado (12 meses). Clinicamente, o clareamento dental pode ser indicado para melhorar a cor dos dentes, independentemente do protocolo pré-estabelecido

The aim of this study was to compare enamel microabrasion (EM) and resin infiltration (RI) techniques in relation to the esthetic resolution of white spot carious lesions (WSL) and to evaluate the correlation between the luminosity of the lesions when transilluminated and the resolution of the problem (study 1); To evaluate in an "in vitro" study, the effectiveness of dental bleaching in samples of teeth previously submitted to RI (study 2); to evaluate the effectiveness of dental bleaching 12 months after the minimal intervention protocols were performed, in a case series study (study 3). For study 1, 17 patients were selected and divided into 2 groups: ME (N=8) and IR (N=9). One tooth from each patient was photographed under normal condition and the same tooth with the aid of a translume device. Then the patients were subjected to the minimal intervention techniques. After 7 days of follow-up, the same photographic protocol was performed. For esthetic resolution, the area of the tooth was delimited in relation to the area of the stain using software. To evaluate the color of the stain when evidenced, the luminosity values (L*) of the coordinates L*a*b* were evaluated before and after the intervention, being measured values of the healthy areas and area of the darker stain. The correlation data were submitted to Person's test. The resolution by the treatments was analyzed by Student's t-test, and the difference in luminosity before and after treatments was analyzed by 2-way repeated measures Anova (p<0.05). For study 2, forty bovine enamel surfaces were subjected to demineralization. Two staining protocols were established. Twenty specimens were immersed in staining broth for 24 hours (Lab 1) or 7 days (Lab 2). Ten specimens from each group received IR application. All specimens were bleached with 15% carbamide peroxide gel for 14 days (8 hours daily). Color measurement was performed by spectrophotometry at three periods: bselien, after staining, and after bleaching. Data (CIEDE00) were analyzed by Student's T test (p <0.05). For study 3, 4 volunteers with WSL in the maxillary teeth were selected. The patients were randomly divided into EM or RI for treating lesions. For esthetic resolution of WSL, the spot area relative to tooth area and the percentage of reduction after protocols were determined. After 12 months of follow-up, the patients received dental bleaching with 10% carbamide peroxide for 21 days. The data from study 1 show that there was no correlation between the stain areas (transilluminated or not) and the esthetic resolution (p>0.05). Regarding resolution, there was no difference between treatments (p=0.403). The Luminosity value increased after the procedures were performed (p=0.001). For study 2, no significant difference was observed in Lab 1 (p=0.560). For Lab 2, significant differences were detected (p=0.031), and whitening was more effective in the group not subjected to IR (Lab2). The results of study 3 show that both protocols reduced and/or softened the areas of the stains. After 12 months of follow-up, the EM technique showed a reduction in the stain area value. Finally, dental bleaching was effective with both protocols, with no differences between the techniques. Based on the proposed methodologies, it can be concluded that: there were no differences between the treatments regarding the removal or masking of WSL; the color of the stains when transilluminated is not related to their esthetic resolution; "in vitro", heavily stained teeth submitted to treatment with RI, the product seems to behave as a semi-permeable barrier to peroxide penetration. Finally, both techniques can be indicated to reduce or soften stained areas. The EM showed a reduction of stained areas in the evaluated period (12 months). Clinically, dental bleaching can be indicated to improve the color of teeth, regardless of the pre-established protocol

The influence of a liner on deep bulk-fill restorations: Randomized clinical trial.

OBJECTIVE: The aim of this study was to evaluate the influence of a liner on the clinical performance of deep posterior restorations performed with bulk-fill composite. METHODS: 30 subjects received two restorations on deep preparations in posterior teeth, without pulpal exposure, after selective carious-tissue removal in one-stage. The internal walls reached the inner quarter of dentin, but with a radiographically detectable zone of firm dentin remaining. The pulpal protection using a layer of glass ionomer composite liner (Ionoseal, Voco) was applied in just one preparation. The adhesive system Futurabond U (Voco) was applied in all preparations, which were restored with the bulk-fill pure Ormocer nanohybrid composite (Admira Fusion Xtra - Voco), in up to 4 mm thick increments. All restorations were evaluated using the FDI criteria after 7 days, 6, 12 and 24 months postoperatively. RESULTS: After 24-months, 25 patients attended the recall and 50 restorations were evaluated. The Fisher's statistical analysis (5%) showed no difference between the techniques for the esthetic, functional and biological properties. No postoperative sensitivity was reported for both groups. CONCLUSION: The application of a liner did not influence the clinical performance of deep restorations with bulk-fill Ormocer composite. CLINICAL RELEVANCE: The application of a liner with a GIC-based material did not have a significant effect on the clinical performance of bulk-fill restorations and seems to be unnecessary for the material tested.

Effectiveness of Home Bleaching Treatment after Resin Infiltrant Application.

PURPOSE: Resin infiltration may be a barrier for bleaching gels. The aim of this study was to compare dental bleaching effectiveness using low-concentration gels on heavily or mildly stained teeth that were or were not treated with resin infiltration agents. MATERIALS AND METHODS: Forty bovine enamel surfaces were submitted to demineralisation, after which two staining protocols were performed. Twenty specimens were immersed in a staining broth for 24 h (Lab 1) or 7 days (Lab 2). Ten specimens of each group received resin infiltrant application following the manufacturer's recommendation. All specimens were bleached using 15% carbamide peroxide gel for 14 days (8 h daily). Colour measurement was performed using a reflectance spectrophotometer at three time points: baseline, after staining, and after bleaching. Data (CIEDE00) were analysed using Student's t-test (p < 0.05). RESULTS: No statistically significant differences were observed in Lab 1 (p = 0.560). For Lab 2, statistically significant differences were detected (p = 0.031). Once bleaching was achieved to some degree (Lab 2), the resin infiltrant may have behaved as a semipermeable barrier to the carbamide peroxide gels. CONCLUSION: Bleaching treatment was effective on mildly pigmented tooth surfaces. On the other hand, in comparison to the control group, the heavily pigmented surfaces bleached less in the presence of the resin infiltrant, possibly due to the lack of free radicals penetrating into the substrate.

A 2-year clinical evaluation of direct and semi-direct resin composite restorations in non-carious cervical lesions: a randomized clinical study.

OBJECTIVES: The purpose of this study was to evaluate the 2-year success of resin composite restorations in non-carious cervical lesions (NCCLs) using the direct or semi-direct techniques. MATERIALS AND METHODS: Thirty volunteers presenting with at least two NCCLs were included. Each participant received one restoration using the direct technique and the other using the semi-direct technique, totaling 60 restorations. Time for completing the treatment was computed. Assessments at baseline, 7 days, and 6, 12, and 24 months were performed using the modified United States Public Health Service criteria. Descriptive analysis was reported as a percentage of successful treatments. For inferential analysis, the Student t test was used to evaluate the differences between extension, depth, and time. The chi-square/Fisher tests were used to compare treatment success after each period (α = 0.05). The results were evaluated by using the Kaplan-Meier survival analysis. RESULTS: Differences were detected regarding mean ± standard deviation time, in which direct and semi-direct procedures were accomplished in 21.8 (± 14.5) and 35.3 (± 19.9) min, respectively. Of the 60 restorations placed, 7 failed in the direct group while 8 failed in the semi-direct group up to 2 years. No differences were detected between restorative protocols. The cumulative survival was 88.5% and 88.4% for the direct technique and semi-direct techniques after 24 months, respectively. CONCLUSION: The tested restorative protocols present similar results for NCCLs within the studied periods. CLINICAL RELEVANCE: The semi-direct technique exhibited clinical performance similar to direct technique for NCCL, demonstrating an alternative for restorations of these lesions.

Three-Month Effect of Silver Diamine Fluoride (SDF) in Salivary Levels of Streptococcus Mutans in Children. An Exploratory Trial.

PURPOSE: The aim of this exploratory trial was to compare the 3-month effect of two antimicrobials on the salivary levels of Streptococcus mutans (SM) in children. MATERIALS AND METHODS: Ninety school children aged 6-10 years participated. They were divided into two groups according to treatment used: 1% chlorhexidine gel (CHX) or 30% silver diamine fluoride (SDF). Saliva for SM colony forming unit (CFU)/ml counting was harvested in four periods: baseline (prior to antimicrobials); P1 (24 h after antimicrobial therapy); P30 (30 days after antimicrobial therapy); and P90 (90 days after antimicrobial therapy). CFU/ml data was submitted to repeated measures by analysis of variance (ANOVA). RESULTS: Only the time factor influenced the results (p <0.001), with a reduction of SM for all evaluated periods in comparison to the baseline. No influence of antimicrobials or interactions of factors were detected (p >0.05). P30 presented the lowest levels of SM and at P90, SM levels were similar to P1 but still lower than the baseline observations. SDF and CHX presented a similar effect on SM within each period of evaluation (p = 0.65). CONCLUSION: It was concluded that 30% SDF presents similar antimicrobial effects as 1% CHX over time. SDF might be used as an adjunctive therapy for controlling dental caries in children.

Protocols to control contamination and strategies to optimize the clinical practice in Restorative Dentistry during the COVID-19 pandemic / Protocolos para controle de contaminação e estratégias para otimizar a prática clínica em Odontologia Restauradora durante a pandemia de COVID-19

The current outbreak of coronavirus 2019 (COVID-19) challenges how professional standards have been defined so far. In Dentistry, biosafety measures already taken by professionals have been intensified, aiming to offer the patient urgent and emergency treatment with safety for both. In this context, Restorative Dentistry is responsible for the care of patients with caries injuries, with or without symptoms and, fractures of teeth and existing restorations. This article guides professionals, during the pandemic period, on the risks involved in adult and pediatric dental care for patients with restorative needs. It also discusses strategies to optimize clinical practice, reducing risks of contamination and virus transmission. (AU)

O atual surto de coronavírus 2019 (COVID-19), fez com que muitos profissionais repensassem sua postura de trabalho. Na Odontologia, medidas de biossegurança já realizadas pelos profissionais, foram intensificadas, com o objetivo de oferecer ao paciente um tratamento de urgência e emergência com segurança para ambos. Neste contexto, a Odontologia Restauradora é responsável pelo atendimento de pacientes com lesões de cárie, com ou sem sintomatologia, e fraturas de dentes e restaurações já existentes. Este trabalho orienta os profissionais quanto aos riscos envolvidos no atendimento odontológico, adulto e pediátrico, de paciente com necessidades restauradoras durante o período de pandemia. O artigo também discute estratégias para otimizar o atendimento, diminuindo riscos de contaminação e transmissão do vírus. (AU)

Auxiliary UV light devices for removal of fluorescent resin residues after bracket debonding.

OBJECTIVE: The purpose of this clinical report was to describe the detection of fluorescent resin residue after orthodontic bracket debonding with two UV light devices and analyze the surface morphology of enamel after 1 year. CLINICAL CONSIDERATIONS: A 22-year-old woman had orthodontic brackets removed by a previous dentist; however, resin residue was left on the enamel of the maxillary teeth. After confirming the fluorescent property of the resin, different protocols were used for each half of the maxillary arch. The first method, a black light lens was attached to a light-curing device to detect resin fluorescence, followed by polishing with silicone rubber tips. The second method used a light emitting diode light system attached to and activated by a high-speed handpiece, followed by polishing with discs. Both methods were completed with diamond polishing paste applied with felt discs. Polyvinyl siloxane impressions were made initially, after residue removal, after finishing and after polishing for morphologic analysis. The results were evaluated with photographs and the scanning electron microscope images made of resin casts from the impressions. A follow-up was made after 1 year. CONCLUSIONS: Both methods yielded a satisfactory clinical outcome, with a smooth surface, acceptable surface gloss and minimal tooth wear. The use of a UV device that excites fluorescence is recommended for the controlled removal of resin residue on enamel. CLINICAL SIGNIFICANCE: The controlled removal of resin residue from enamel after orthodontic treatment is challenging but can be improved with auxiliary methods for detecting resin residues. This clinical report describes two types of devices that excite fluorescent resins in a more rapid and precise technique to guide the practitioner in the controlled removal of residual resin on teeth.

Effects of artificial staining on bulk-filled resin composites.

PURPOSE: To evaluate the color stability of bulk-fill resin composites (RC) in comparison to conventional RC submitted to artificial staining. METHODS: 15 specimens of each RC were prepared. Five bulk-fill RC [X-tra Base (XB), Filtek Bulk-Fill Flowable (FBF), Admira Fusion X-tra (AD), Tetric N-Ceram Bulk-Fill (TB), and Filtek Bulk-Fill (FB) ], and two conventional RC [GrandioSO (GO) and Filtek Z350XT (FXT) ] were used. After preparation of the samples, the specimens were immersed in a staining broth for 5 weeks and repolished. The color change was assessed using a spectrophotometer. Data were analyzed using one-way ANOVA, Tukey's tests, and paired t-test. RESULTS: The bulk-fill flowable (XB and FBF) presented color change clinically acceptable (ΔE< 2.7) after staining. Among the bulk-fill regular resins, only AD presented clinically acceptable values (ΔE= 1.99). Regarding the conventional resins, GO presented a significantly lower color change than the other resins, but was not significantly different from AD. For all the resins, except AD, the repolishing procedures resulted in a significant decrease of color change. Tested resins did not present the same behavior under staining, despite their similarities. All the resins stained above the perceptibility threshold (ΔE> 1.2). After repolishing, the color change was reduced overall. CLINICAL SIGNIFICANCE: Color stability of resin composites was related to the properties of the resin material. The staining degree was related to the replacement of the restorations and repolishing contributes to the maintenance and longevity of these composites.

Influence of illuminants and different observers on the perception of surface gloss of resin composite / Influência de diferentes iluminantes e observadores na percepção do brilho superficial da resina composta

Objective: To evaluate the visual perception of surface gloss of resin composite under different illuminants by different observers. Material and methods: twelve cylindrical specimens (6mm x 1mm) were fabricated using a nanofilled resin composite (Z350, A2E shade) in order to compare different observers and to determine the limit of perceptibility of surface gloss. Bovine tooth specimen with similar dimensions was obtained for the comparison of different illuminants. Polishing of resin specimens was performed resulting in 6 groups, presenting surface gloss values at 10, 25, 40, 55, 70, and 85 GU (gloss units), measured by glossmeter (NOVOCURVE). Fifteen individuals were selected: 5 lay-person, 5 undergraduate students, and 5 dental professionals. Participants observed the specimens in a light booth (Gti lightbox) under three different illuminants, and rated the possible combinations between resin specimens or with the bovine enamel specimen (85GU). Data obtained were analyzed by PROBIT non-linear regression analysis (α=0.05). Results: Differences were observed among types of illuminants (p=0.042) and ΔGU (p=0.004), with no interaction between factors (p=0.139). The fluorescent light presented lower surface gloss perceptibility values in relation to incandescent light. There was no influence by type of observers (p=0.598). The surface gloss perception limit was 17.6 GU under the presented tested conditions. Conclusion: the illuminant type influenced perception of gloss, with lower percentage of perceptibility for fluorescent light, while such perceptibility was not influence by different observers. (AU)

Objetivo: Avaliar a percepção visual e táctil do brilho superficial da resina composta sob diferentes iluminantes e por diferentes observadores. Material e métodos: foram utilizados doze espécimes cilindricos (6mm x 1mm) fabricados em resina composta nanoparticulada (Z350, 3M ESPE- cor A2E) para comparar diferentes observadores e determinar o limite de perceptibilidade do brilho superficial. Um espécime em dente bovino com dimensões similares foi obtido para a comparação de diferentes iluminantes. O polimento do espécime de resina foi realizado, resultando em 6 grupos (n=2), apresentando valores de brilho superficial em 10, 25, 40, 55, 70 e 85 UB (unidades de brilho), medido por um medidor de brilho (NOVOCURVE ­ Rhopoiny TM, East Sussex, Inglaterra). Foram selecionados quinze indivíduos : 5 leigos, 5 alunos de graduação e 5 profissionais de odontologia. Os participantes observaram espécimes em uma cabine de luz (Gti lightbox, New Jersey, USA), sob três iluminantes diferentes, e avaliaram as possíveis combinações entre espécimes de resina ou com espécime de esmalte bovino (85 UB). Resultados: os dados obtidos foram analisados por análise de regressão não-linear PROBIT (5%). As diferenças foram observadas entre os tipos de iluminantes (p= 0,042) e Δ UB (p= 0,004), sem interação entre os fatores (p= 0,139). A luz fluorescente apresentou valores de percepção de brilho da superfície inferior em relação á luz incandescente. Não houve influência pelo tipo de observadores (p= 0,598). O limite de percepção do brilho superficial foi de 17,6 UB sob as condições testadas apresentadas. Conclusão: o tipo de iluminante influenciou na percepção do brilho, com menor porcentagem de perceptibilidade para luz fluorescente (p=0,042), enquanto que a perceptibilidade não foi influenciada pelos diferentes observadores. (AU)

Effect of Artificial Aging Protocols on Surface Gloss of Resin Composites.

The purpose of this study was to evaluate the effect of aging protocols on surface gloss of composites. Cylindrical resin composite specimens (6 mm in diameter, 1 mm thick) were fabricated and divided into three groups (N = 60): microfilled (MiFi), nanohybrid (NaHy), and nanofilled (NaFi). Specimens were distributed into four aging subgroups: thermocycling (5° to 55°C, 15,000 cycles); ethanol immersion (15 days); brushing (10,750 cycles); and light aging (216 h). Surface gloss readings (Novo-Curve, Rhopoint TM, England) were performed at baseline (R0) and after every one-third of aging protocols (R1 to R3). Data were submitted to one-way repeated measures ANOVA and Tukey's test (5%). Overall, surface gloss alterations were detected over time (p < 0.001). Thermocycling reduced surface gloss, except for NaHy. Ethanol immersion resulted in surface gloss reduction after R1 for MiFi and NaFi, while reduction after R1 and R2 was detected for NaHy. For brushing, gloss reduction was detected after R1 and R3 for all composites. For light aging, gloss was reduced after R1 and R2 for MiFi and NaFi, while a reduction only after R1 was detected for NaHy. The studied aging protocols affect surface gloss differently, being material and aging therapy dependent. In general, the surface gloss is reduced with aging.

Efficacy of auxiliary devices for removal of fluorescent residue after bracket debonding.

OBJECTIVE: To evaluate four protocols for removal of fluorescent materials after bracket debonding. MATERIALS AND METHODS: Resin removal from 40 bovine enamel surfaces was performed according to groups (n = 10): conventional (C), white LED (W), LED that evidenced fluorescence (F), and fluorescent lens (FL). The following analyses were performed: sample thickness, superficial area of resin residue, and areas of resin residue or worn enamel in depth. ANOVA and Tukey tests were used to analyze sample thickness (P ≤ .05). Area measurements were analyzed by Kruskal-Wallis and Dunn's tests (P ≤ .05). RESULTS: The FL group showed the highest reduction in enamel thickness. F group final thickness was similar to that of other groups. The largest superficial areas of resin residue were found for the C and W groups, while the FL group had the greatest removal of resin residue. The C group exhibited the largest area in depth of resin residue. The FL and F groups exhibited the most loss of enamel with the least amount of resin residue; in contrast, the C and W groups presented the fewest areas of worn enamel and the most areas of resin residue. CONCLUSION: Auxiliary devices were useful for removal of fluorescent residue after bracket debonding.

Influência do observador, do iluminante e do ângulo de visualização na perceptibilidade e aceitabilidade de diferenças de brilho superficial de resinas compostas / Influence of observer, illuminant and visualization field on perception and acceptability the difference of surface gloss of resin composites

O objetivo deste trabalho foi avaliar a influência de observadores sobre a percepção e aceitabilidade de brilho superficial de resinas compostas, sob diferentes iluminantes, em angulação livre e pré-determina em 60°. E ainda, determinar o limite de perceptibilidade e aceitabilidade da variação de unidade de brilho (ΔUB) entre os espécimes. Foram confeccionados 8 espécimes cilíndricos de 6 mm de diâmetro e 1,5 mm de espessura de resina composta, bem como um espécime padrão de dente humano, com 0,5 mm de espessura em esmalte e 1 mm em dentina. Os espécimes receberam polimento a fim de que se obtivesse ao final do processo amostras com 10 UB, 20 UB, 30 UB, 40 UB, 50 UB, 60 UB, 70 UB e 80 UB e um padrão de dente humano de 80 UB. Foram selecionados 60 observadores (20 leigos, 20 alunos de graduação e 20 cirurgiões-dentistas). O estudo foi submetido e aprovado pelo comitê de ética local. Os participantes fizeram a qualificação do brilho superficial de resina composta em cabine de luz (Gti ­ Newburgh,NJ). Para tanto, as amostras foram posicionadas no interior da cabine, duas a duas de forma aleatória, de forma com que a luz incidisse sua superfície em um ângulo de 60°. Os observadores responderam perguntas específicas para se determinar o nível e limite de perceptibilidade das variações de brilho. Todas as análises foram realizadas em duas condições de iluminação, com iluminantes D65 e luz fluorescente. Cinquenta por cento dos observadores iniciaram as análises com ângulo de visualização livre, seguido da qualificação em angulação pré-definida em 60° e, os demais observadores fizeram as observações de forma oposta. Para o nível e limite de aceitabilidade da variação do brilho, as amostras foram individualmente comparadas com o padrão de dente humano. Os dados foram analisados pelo teste Modelo Generalizado Linear/Não-Linear PROBIT e regressão não-linear PROBIT (5%). Para a perceptibilidade, foram encontradas diferenças significantes para a variação de brilho (Δ UB) (p<0,001), para os observadores (p=0,043) e para os iluminantes (p<0,001), no entanto, não houve diferença entre o ângulo de visualização livre e fixo em 60° (p=0,303). Em relação à aceitabilidade, foram observadas diferenças significantes para a variação de brilho (Δ UB) (p<0,001), para os observadores (p=0,003), para os iluminantes (p=0,045) e no ângulo de visualização livre e fixo em 60° (p<0,001). Os limites de perceptibilidade e aceitabilidade, levando em consideração todos os fatores foi de 6,4 UB e 35,7 UB, respectivamente. Conclui-se que fatores rotineiramente encontrados em situações clínicas influenciam a perceptibilidade e aceitabilidade de diferenças de brilho superficial de resinas compostas e que apesar de perceberem limites menores de diferença de brilho, os observadores aceitam clinicamente diferenças cinco vezes maiores(AU)

The aim of the present study was to assess the influence of observers on gloss perception and acceptability of resin composites, with different illuminant exposures, under non-determined visualization field or at 60°; and also to determine the limit of perceptibility and acceptability of gloss unit variation (ΔGU) between specimens. Eight composite resin specimens presenting 6 mm in diameter and 1.5 mm thick were fabricated. A human tooth specimen (1 mm dentin and 0.5 mm enamel) was also obtained. Specimens were polished to obtain surface gloss, in gloss units (GU), at 10 GU, 20 GU, 30 GU, 40 GU, 50GU, 60 GU, 70 GU, and 80 GU; while human tooth specimen presented 80 GU. Sixty observers were selected for the analyses (20 laypersons, 20 students, and 20 dentists). The study was submitted to and approved bythe local Institutional Review Board. Subjects compared the surface gloss of specimens in a light booth (Gti ­ Newburgh, NJ). Specimens were randomly placed, two at a time, in the light booth with light incidence at 60°. Observers answered to specific questions to determine the levels and limits of perceptibility of surface gloss variations. All analyses were performed under two illuminant conditions, being D65 and fluorescent light. Fifty percent of observes started the analyses with non-determined visualization field, followed by determined visualization field at 60o. The rest 50% performed observations in opposite order. The levels and limits of acceptability of surface gloss, were determined by individually comparing resin specimens and human enamel sample. Data were submitted to General linear/non-linear model PROBIT and non-linear regression estimation PROBIT (5%). For the perceptibility, significant differences were observed for the gloss variation (Δ GU) (p <0.001), for the observers (p = 0.043) and for different illuminant exposures (p <0.001). However, there was no difference between 60° or non-fixed visualization fields (p = 0.303). For the acceptability, significant differences were observed for the gloss variation (Δ GU) (p <0.001), for the observers (p = 0.003), for different illuminant exposures (p =0.045), and for different illuminant exposures (p<0.001). The limit of perceptibility and acceptability, considering all the factors was 6.4 GU and 35.7GU, respectively. It was concluded that factors routinely found in clinical situations influence the perceptibility and acceptability of differences surface glossvariations and that despite perceiving lower limits of gloss difference, observers clinically accept differences five times greater(AU)