Modificação de uma resina composta Bulk Fill Flow com extrato acetônico da casca da romã / Modification of a Bulk Fill Flow composite resin with acetonic extract from pomegranate peel

Introdução: A cárie dentária ainda se constitui um problema de saúde pública. Áreas adjacentes a restaurações são frequentemente acometidas por cárie. Por mais que as resinas compostas estejam sendo estudadas e melhoradas, ainda não apresentam atividade antimicrobiana. As cascas da romã (Punica Granatum) são um recurso potencial para compostos bioativos como fenólicos, proantocianidinas e flavonoides, além de apresentarem atividade antioxidante e efeito inibitório contra bactérias Gram-negativas e Gram-positivas. Objetivo: modificar a resina composta Opus Bulk Fill Flow (FGM®) com o extrato acetônico da casca da romã em diferentes concentrações e avaliar a rugosidade da superfície e mudança de cor. Metodologia: foi realizada a extração de 5g de casca da romã utilizando 100mL de solvente acetona 70%. Após rotaevaporação, filtragem e liofilização do extrato, este foi macerado, peneirado e pesado em concentrações diferentes a partir da concentração inibitória mínima capaz de inibir o crescimento de Streptococcus mutans ATCC 700610. A resina composta Opus Bulk Fill Flow foi modificada com esse extrato em diferentes concentrações de forma a gerar 5 grupos: Controle 0 µg (n=10), G930 µg (n=10), G1860 µg (n=10), G3730 µg (n=10) e G7460 µg (n=10). Rugosidade (Ra), diferença de cor (ΔE00) e índice de brancura (WID) foram submetidos aos testes de normalidade. Os dados não-paramétricos de Ra foram submetidos ao teste de Kruskal-Wallis com pós-teste de Dunn e os dados paramétricos do ΔE00 e WID foram submetidos ao teste ANOVA 1 Fator com pósteste de Tukey por meio do software GraphPad Prism 8 e Microsoft Excel 2019. Resultados: Verificou-se que a média do índice de brancura (WID) diminuiu conforme o aumento da concentração do extrato na resina modificada (p<0,05), assim como, as resinas modificadas se tornaram, visivelmente a olho nu, um pouco mais amareladas. Após 1 mês, as amostras dos grupos experimentais sofreram a mesma variação de cor (ΔE00) que o grupo controle, uma vez que os valores das médias foram semelhantes. Portanto, todos os grupos apresentaram estabilidade de cor. A rugosidade superficial (Ra) não mostrou diferença estatisticamente significativa (p>0,05). Todos os grupos apresentaram médias com valores similares a 0,06µm. Conclusão: A alteração de cor na resina, com a inserção do extrato, ainda na maior concentração, se manteve na classificação do matiz A. O que não afeta as propriedades organolépticas e pode ser considerada uma cor similar à cor dos dentes naturais. A adição do extrato na resina manteve a rugosidade superficial de todos os grupos dentro do valor ideal, prevenindo a adesão de biofilmes e microrganismos e proporcionando conforto ao toque da língua (AU).

Introduction: Dental caries still constitutes a public health problem. Areas adjacent to restorations are often affected by caries. Even though resin composites are being studied and improved, they still do not have antimicrobial activity. Pomegranate peels (Punica Granatum) are a potential resource for bioactive compounds such as phenolics, proanthocyanidins and flavonoids, in addition to presenting antioxidant activity and inhibitory effects against Gram-negative and Gram-positive bacteria. Objective: to modify the Opus Bulk Fill Flow (FGM™) resin composite with the acetone extract of pomegranate peel in different concentrations and evaluate the surface roughness, and color change. Methodology: 5g of pomegranate peel was extracted using 100mL of 70% acetone solvent. After rotary evaporation, filtering and lyophilization of the extract, it was macerated, sieved and weighed at different concentrations based on the minimum inhibitory concentration capable of inhibiting the growth of Streptococcus mutans ATCC 700610. The Opus Bulk Fill Flow resin composite was modified with this extract in different concentrations to generate 5 groups: Control 0 µg (n=10), G930 µg (n=10), G1860 µg (n=10), G3730 µg (n=10) e G7460 µg (n=10). Roughness (Ra) and color difference (ΔE00) were subjected to normality tests and non-parametric data were subjected to the Kruskal-Wallis test with Dunn's post-test using GraphPad Prism 8 and Microsoft Excel 2019 software. Results: It was found that the average whiteness index (WID) decreased as the concentration of the extract in the modified resin increased (p<0.05), as well as the modified resins became, visibly to the naked eye, a little more yellowish. After 1 month, samples from the experimental groups suffered the same color variation (ΔE00) as the control group, since the average values were similar. Therefore, all groups showed color stability. Surface roughness (Ra) did not show a statistically significant difference (p>0.05). All groups presented average values similar to 0.06µm. Conclusion: The color change in the resin, with the insertion of the extract, even at the highest concentration, remained in the classification of hue A. This does not affect the organoleptic properties and can be considered a color similar to the color of natural teeth. The addition of the extract to the resin composite maintained the surface roughness of all groups within the ideal value, preventing the adhesion of biofilms and microorganisms and providing comfort to the touch of the tongue (AU).

Surface roughness of three different glass ionomers with our without finishing/polishing: an in vitro study

Purpose: This study aimed to compare the surface roughness among 3 types of glass ionomers (GI) before (no polishing) and after polishing with three different materials. Methods: 20 discs for each GI group were obtained (A-Ionolux; B-IonoStar Plus; C-Ketac). Those groups were subdivided according to finishing and polishing: subgroups 1 (control) - no polishing, 2 - polishing with prophylactic brush and pumice paste, 3 - Enhance tips with water, and 4 - Sof-Lex system with Easy Glaze and polymerization. For each disc face, the total distance analyzed was 2.88cm (6x48mm). Then, the roughness was compared using the Kruskal-Wallis with Bonferroni test, with significant data if p<0.05. Results: The mean of roughness within Group A was lower for subgroup 4 (1.07±0.54 µm) and higher for subgroup 2 (2.33±1.17 µm). Within group B, B4 had the lowest mean of roughness (0.93±0.38 µm) and B2 (1.24 ± 0.78 µm) the highest roughness. Within group C, Group C4 had the lowest mean roughness value (0.84±0.54 µm), and C3 had the highest mean (2.48±1.05 µm). After polishing, subgroup 4 had the general lowest values for surface roughness (mean Ra 0.95), followed by subgroup 1 (Ra=1.27), subgroup 2 (Ra=1.89), and higher values for subgroup 3. All intragroup analysis for A, B, and C were statistically significant. Group A presented the highest roughness (p<0.05), and no statistically significant evidence existed between groups B and C (p>0.05). Conclusion: The reduction of the roughness of the materials is dependent on their composition and the polishing and finishing techniques applied.

Evaluation of surface roughness and fracture resistance of maxillary conventional & digital complete dentures: An Invitro study

Aim: to evaluate the surface roughness and fracture resistance of complete dentures made using heat-cured polymethyl methacrylate (PMMA) resin manufactured by conventional technique & digital complete dentures manufactured by additive manufacturing technique. Materials and Methods: A total of 24 complete dentures were made (n=24), 12 dentures were made using heat-cured polymethyl methacrylate (PMMA) resin manufactured by the conventional methods. 12 dentures were designed by Exocad software program & constructed using additive manufacturing technique. Surface roughness was evaluated using optical profilometry. Fracture resistance was evaluated using universal testing machine. Data were analysed using unpaired t-test where α = 0.05. Results: There was no statistically significant difference found between the two groups when comparing the surface roughness values (P=0.5137). Conventional PMMA dentures showed mean (2.52± 0.14 µm), while 3D-printed dentures showed mean (2.59± 0.38 µm). However, regarding the fracture resistance, there was statistically significant difference found between the two groups (P(P<0.5), the conventional PMMA dentures showed higher mean (572.49± 13.07 N), while the digital dentures showed lesser mean with (202.51 ± 10.35 N). Conclusion: Conventional PMMA dentures and 3D-printed dentures had similar surface roughness. However conventional PMMA dentures had better fracture resistance when compared to 3D-printed dentures

A microscopia eletrônica de varredura pode ser usada para medir quantitativamente a rugosidade da dentina? / Can Scanning Electron Microscopy be used to quantitatively measure dentine roughness?

Objective: The aim of this study was to determine if SEM used with imaging software could be used to quantitatively determine the extent of dentine roughness due to tooth-brushing. Material and methods: Flat, polished dentine surfaces were subjected to 25,000 cycles of simulated tooth-brushing at 2 strokes per second with a load of 200 g. At the end of the brushing cycle, dentine surfaces were first assessed using profilometry and then subjected to SEM analysis. Ra (average roughness) readings were obtained for profilometric assessment. Using imaging software, the horizontal distance between adjacent characteristic grooves noted on micrographs was measured, ensuring that the middle of each crest of the associated groove was used as the reference point, the Crest-to-Crest distance (C-C distance). These two parameters were examined statistically for correlation. Results: When Spearman Rank tests were utilized the correlation between average Ra and crest to crest measurements was 0.709 (p <0.01). The Bland Altman plot, however, showed poor agreement between the two test parameters. Conclusion: Further work is needed to validate the use of this methodology in the quantitative assessment of tooth surface loss due to abrasion (AU)

Objetivo: O objetivo deste estudo foi determinar se o MEV usado com software de imagem poderia ser usado para determinar quantitativamente a extensão da rugosidade da dentina devido à escovação dentária. Material e Métodos: Superfícies dentinárias planas e polidas foram submetidas a 25.000 ciclos de escovação dentária simulada a 2 movimentos por segundo com uma carga de 200g. No final do ciclo de escovação, as superfícies dentinárias foram primeiro avaliadas por perfilometria e depois submetidas à análise MEV. Leituras de Ra (rugosidade média) foram obtidas para avaliação perfilométrica. Utilizando um software de imagem, foi medida a distância horizontal entre sulcos característicos adjacentes observados nas micrografias, garantindo que o meio de cada crista do sulco associado fosse usado como ponto de referência, a distância crista a crista (distância CC). Esses dois parâmetros foram examinados estatisticamente para correlação. Resultados: Quando foram utilizados os testes de Spearman Rank, a correlação entre a média de Ra e as medidas de crista a crista foi de 0,709 (p<0,01). O gráfico de Bland Altman, no entanto, mostrou fraca concordância entre os dois parâmetros de teste. Conclusão: Mais trabalhos são necessários para validar o uso desta metodologia na avaliação quantitativa da perda da superfície dentária devido à abrasão(AU)

Effect of Water and Chlorhexidine with Different Pressures of Oral Irrigation Device on the Surface Roughness and Topography of Giomer

Abstract Objective: To evaluate the effect of different pressures of an oral irrigation device (OID) and the irrigation solution type on the surface roughness of the giomer restorative material. Material and Methods: In this in vitro study, disk-shaped giomer samples were fabricated and assigned to 5 groups (n=23): Group 1, storage in distilled water (control); Group 2, OID #7 pressure/ water; Group 3, OID #10 pressure/ water; Group 4, OID #7 pressure/ 0.05% CHX; Group 5, OID #10 pressure/ 0.05% CHX. The samples' treatment simulated a one-year application of OID. Surface roughness (Ra) and topography of the giomer were evaluated using profilometry and scanning electron microscopy. The data were analyzed with Paired t-test, Tukey, and ANOVA tests (α=0.05). Results: The Ra of the samples increased significantly after treatment with OID (p<0.001). The roughness increase in groups with a pressure of 10 was higher than those with a pressure of 7 (p<0.001). The effect of pressure on surface changes was significant (p<0.001). However, the solution type and the cumulative effect of these two factors were insignificant (p=0.08 and p=0.43, respectively). Conclusion: Oral irrigation device with both solutions significantly increased the surface roughness and topographic changes of the giomer. The severity of these changes was related to the device's pressure.

Surface roughness of resin-based composites subjected to professional prophylaxis / Rugosidade de superfície de resinas compostas após profilaxia profissional

Objetivo: Avaliar o efeito de dois métodos de profilaxia sobre a rugosidade superficial de diferentes resinas compostas. Materiais e Métodos: Dez amostras (7 mm x 2 mm) foram confeccionadas para cada resina testada: MH - resina microhíbrida (viscosidade regular - Opallis); NH ­ resina nanohíbrida (viscosidade regular - Vittra APS); BF ­ resina bulk fill (alta viscosidade - Opus Bulk Fill); MHF ­ resina fluida microhíbrida (Opallis flow); e OS ­ resina nanohíbrida camaleão (viscosidade regular - Vittra Unique). Os valores iniciais de rugosidade (Rai) foram obtidos para cada amostra e então subdivididas em dois grupos (n = 5) seguindo o método de profilaxia: SB ­ jato de bicarbonato de sódio (125µm, 30 s, 10 mm de distância, 2 bar); e PP ­ profilaxia com pasta de pedra-pomes e escova rotatória (30 s, 3000 rpm e pressão de 150 g). Após, uma nova medida de Ra (Raf) foi obtida, e a diferença calculada (ΔRa). Os dados foram analisados pelo teste ANOVA três fatores e teste de Bonferroni, e a diferença de rugosidade (ΔRa) pelo teste Anova dois fatores e teste de Tukey (p<0,05). Resultados: MHF apresentou maior rugosidade após profilaxia com jato de bicarbonato, enquanto para NH a abrasão com pedra pomes foi mais deletéria. Para os demais grupos não houve diferença. Discussão: A alteração na rugosidade promovida pela profilaxia é material-dependente. Conclusão: A profilaxia profissional com jato de bicarbonato ou abrasão com pedra-pomes induziu alterações na rugosidade das resinas.

Aim: This study evaluated the effect of two prophylaxis methods over the surface roughness of different resin composites. Materials and Methods: Ten disc-shaped specimens (7 mm x 2 mm) were made for each composite tested: MH - microhybrid composite with regular viscosity (Opallis); NH ­ nanohybrid composite with regular viscosity (Vittra APS); BF ­ high-viscosity bulk fill composite (Opus Bulk Fill); MHF - microhybrid flowable composite (Opallis flow); and OS ­ nanohybrid one-shade composite with regular viscosity (Vittra Unique). Initial roughness (Ra) values were obtained from each sample, and then they were divided into two groups (n = 5) following the prophylaxis method: SB ­ prophylaxis with sodium bicarbonate powder (125µm grain) using an air-powder polishing device (30 s application distanced 10 mm with 2 bar); and PP ­ prophylaxis with pumice paste and rotatory brush (30 s, 3000 rpm and pressure of 150 g). After that, a new Ra measurement (Raf) was obtained, and the difference was calculated (ΔRa). Data were compared using Three-way ANOVA followed by Bonferroni teste and the Ra difference (ΔRa) was analyzed by Two-way ANOVA followed by the Tukey test (p<0.05). Results: MHF presented higher Ra values after receiving prophylaxis with SB, while for NH, the abrasion with pumice increased the Ra, and for the other groups, no differences were found. Discussion: Alteration promoted by prophylaxis is material dependent. Conclusion: Professional prophylaxis with a bicarbonate jet or abrasion with pumice-based paste can induce changes in the composites' roughness.

Efeito dos diferentes tipos de polimento sobre a rugosidade de superfície de uma resina acrílica comercial quimicamente ativada: estudo in vitro / Effect of different types of polishing on the surface roughness of a chemically activated commercial acrylic resin: an in vitro study

Objetivo: avaliar in vitro o polimento sobre resina acrílica quimicamente ativada (RAQA), por meio da rugosidade de superfície (Ra). Materiais e Método: Foram confeccionadas 40 amostras de RAQA, com dimensões de 10 a 10 x 2 mm, e foram divididas em quatro grupos (n=10): ausência do acabamento (AA); Ausência de polimento (AP); Polimento químico (PQ); Polimento com borrachas siliconadas + Escovas (PM). Os espécimes foram avaliados no quanto a rugosidade média (Ra) antes e após o envelhecimento em água destilada em uma estufa por 60 dias. Três medições de Ra (µm), na horizontal foram realizadas e calculada uma média para cada espécime. Os dados foram analisados de forma descritiva e inferencial, ANOVA de medidas repetidas e teste de Tukey com nível de significância de 5%. Resultados: Inicialmente, o grupo AA teve os menores valores de Ra e o grupo AP os maiores valores de rugosidade, com média e desvio padrão respectivamente 0,17 (±0,11) e 0,52 (±0,10). Após o envelhecimento, o grupo AA teve as menores médias e o grupo PQ os maiores valores de Ra, sendo 0,38 (±0,20) e 1,33 (±0,32), respectivamente. Os resultados evidenciaram diferença estatística significante quando as amostras foram submetidas ao acabamento com brocas. Conclusão: A RAQA necessita de polimento após acabamento com brocas, uma vez que a ausência de polimento comprometerá a lisura de superfície do material.(AU)

Objective: to evaluate in vitro polishing on chemically activated acrylic resin (RAQA), using surface roughness (Ra). Materials and Method: 40 RAQA samples were made, measuring 10 to 10 x 2 mm, and divided into four groups (n=10): absence of finishing (AA); Lack of polishing (AP); Chemical polishing (PQ); Polishing with silicone rubbers + Brushes (PM). The specimens were evaluated for their average roughness (Ra) before and after aging in distilled water in an oven for 60 days. Three horizontal Ra (µm) measurements were taken and an average was calculated for each specimen. Data were analyzed descriptively and inferentially, using repeated measures ANOVA and Tukey test with a significance level of 5%. Results: Initially, the AA group had the lowest Ra values and the AP group the highest roughness values, with mean and standard deviation respectively 0.17 (±0.11) and 0.52 (±0.10). After aging, the AA group had the lowest averages and the PQ group the highest Ra values, being 0.38 (±0.20) and 1.33 (±0.32), respectively. The results showed a statistically significant difference when the samples were finished with drills. Conclusion: RAQA requires polishing after finishing with drills, as the lack of polishing will compromise the surface smoothness of the material.(AU)

Root filling quality and bond strength of endodontic sealers to human and bovine dentin / Qualidade da obturação e resistência de união de cimentos endodônticos à dentina humana e bovina

Objetivo: Este estudo teve como objetivo comparar a qualidade da obturação e a resistência de união de dois cimentos endodônticos, AH Plus e Bio-C Sealer, em dentes humanos e bovinos. Métodos: Os canais radiculares de 60 dentes unirradiculares [30 humanos (H) e 30 bovinos (B)] foram preparados e obturados por condensação lateral da guta-percha e AH Plus (grupos AP-H e AP-B) ou Bio-C Sealer (grupos BC-H e BC-B). Seis fatias de 1,5 mm de espessura foram obtidas de cada raiz. Os espécimes foram observados em estereomicroscópio para avaliar a qualidade da obturação, considerando possíveis espaços vazios no material obturador. Posteriormente, as fatias radiculares foram avaliadas em termos de resistência de união por push-out e modo de falha. Os dados foram analisados pelos testes de Mann-Whitney e coeficientes de correlação de Spearman (α=5%). Resultados: A qualidade de obturação fornecida por AP e BC foi semelhante em ambos os substratos de dentina. No entanto, ao comparar dentes humanos e bovinos, os escores de espaços vazios foram maiores nas amostras bovinas, para ambos os cimentos. AP teve maior resistência de união à dentina humana e bovina do que BC. No entanto, não houve diferença significativa na resistência de união entre os substratos dentinários, para ambos os cimentos testados. Além disso, houve uma correlação positiva e moderada entre os valores de resistência de união de dentes humanos e bovinos. O modo de falha misto foi o mais prevalente. Conclusão: AP e BC fornecem qualidade de obturação semelhante, mas o primeiro apresenta maiores valores de resistência de união à dentina humana e bovina. A utilização de dentes bovinos como substitutos de amostras humanas parece ser adequada em estudos relacionados à resistência de união, mas não naqueles que testam a qualidade da obturação endodôntica.(AU)

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.(AU)

Advances in surface treatment of dental implants: a literature review

Amplamente utilizados para substituir dentes perdidos, os implantes dentários nos últimos anos vêm apresentando tecnologias como superfícies com micro e nanotopografia e ajustes nas composições químicas, dentre outros, para melhorar a osseointegração e reduzir o prazo de tratamento, permitindo, assim, carga funcional imediata ou precoce em pacientes com densidade óssea reduzida. Vários métodos são aplicados com intuito de modificar a superfície do implante, como jateamento com areia, corrosão ácida, oxidação anódica, tratamento com flúor, usinagem, pulverização de plasma de titânio e revestimento de fosfato de cálcio; esses métodos podem aumentar notavelmente a área de superfície quando operada a técnica adequadada de modificação, quer por procedimento de adição ou subtração. Tais modificações promovem superfícies rugosas, as quais aumentam a porcentagem de contato osso-implante (BIC) durante o processo de cicatrização óssea inicial. Os principais benefícios da modificação da superfície são melhorar a molhabilidade (hidrofilicidade), adesão e fixação de células a implantes e proliferação celular. Dentre os tratamentos de superfície de implantes dentários destaca-se o jateamento de areia com granulação grossa e ataque-ácido com HCL/H2SO4 (SLA) em altas temperaturas, o revestimento de superfície do implante com hidroxiapatita, oxidação anódica e o duplo ataque ácido. O objetivo deste trabalho é realizar uma revisão de literatura discutindo a importância e eficácia desses métodos para a osseointegração e, por conseguinte, para a redução do período de tratamento.

Widely used to replace lost teeth, dental implants have been presenting technologies such as surfaces with micro and nano topography and adjustments in chemical compositions, among others, to improve osseointegration and reduce treatment time, thus allowing immediate or early functional load in patients with reduced bone density. Several methods are applied to modify the implant surface, such as sandblasting, acid corrosion, anodic oxidation, fluoride treatment, machining, titanium plasma spraying, and calcium phosphate coating; these methods can notably increase the surface area when the appropriate modification technique is operated, either by the addition or subtraction procedure. Such modifications promote rough surfaces, which increase the percentage of bone-implant contact (BIC) during the initial bone healing process. The main benefits of surface modification are to improve wettability (hydrophilicity), adhesion and attachment of cells to implants, and cell proliferation. Among the surface treatments for dental implants, sandblasting with large grit and acid-etching with HCL/H2SO4 (SLA) stands out at high temperatures. The surface coating of the implant with hydroxyapatite, anodic oxidation, and double acid-etching. This work aims to conduct a literature review discussing the importance and effectiveness of these methods for osseointegration and, therefore, for reducing the treatment period.

Research on friction and wear behaviors of silicon-lithium spray coating on zirconia ceramics / 北京大学学报(医学版)

OBJECTIVE@#To study microstructure, friction and wear behaviors of silicon-lithium spray coating on the surface of zirconia ceramics and to preliminarily evaluate its esthetic so as to provide support and guidance for the clinical application.@*METHODS@#Zirconia ceramic specimens were randomly divided into three groups: coating group (two subgroups), polishing group (two subgroups), and glazing group (four subgroups), with 10 samples in each subgroup. The two subgroups of coating group were the zirconia ceramics with the untreated and preliminary polishing surfaces sprayed with silicon-lithium coating, respectively. The two subgroups of polishing group were preliminary polishing and fine polishing of zirconia ceramics, respectively. The four subgroups of glazing group were preliminarily polished zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively; and untreated zirconia ceramics glazed with Biomic and Stain/Glaze products, respectively. The above 8 subgroups of zirconia ceramic specimens were used as friction pairs with 80 steatite ceramics for 50 000 chewing cycles under 50 N vertical load and artificial saliva lubrication using chewing simulation. Scanning electron microscope was used to observe the microstructure of the surface and section of the coating group, and the thickness of the coating and glazing were measured. The linear roughness of the coating and polishing groups was mea-sured using a laser confocal scanning microscope. Vickers hardness was measured using a microhardness tester and the esthetic of zirconia ceramic full crown sprayed with silicon-lithium coating was preliminarily evaluated. White light interferometer was used to measure the width, the maximum depth and the volume of the wear scars of each group, and the wear depth of steatite ceramics and wear rate of zirconia ceramic specimens were calculated. Kruskal-Wallis nonparametric test and Dunn's multiple comparisons test were used to analyze the wear depth of each group (α=0.05).@*RESULTS@#The microstructures of the silica-lithium spray coatings on the untreated and preliminarily polished zirconia ceramic surfaces showed the protruding defects, and the line roughness of coating group was larger than that of the polishing group. The median thickness of the silica-lithium spray coating on the preliminarily polished zirconia ceramic was 13.0 μm (interquartile range, IQR: 11.6, 17.9), while that of the silica-lithium spray coating on the untreated zirconia ceramic was 4.4 μm (IQR: 4.1, 4.7). The Vickers hardness and wear rate of the coating group were between the polishing group and the glazing group. The wear depths of the wear scars of steatite ceramics were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference between glazing and polishing groups (P < 0.05). With the increase of polishing procedure, the wear depth of steatite ceramics decreased in each subgroups. The orders of maximum depth and volume of wear scars of zirconia ceramic were the glazing group, coating group, and polishing group in descending order, and there was statistically significant difference in the maximum depth of wear scars between glazing and polishing groups (P < 0.05).@*CONCLUSION@#The silica-lithium spray coating on the zirconia ceramic, can be used as a new method for zirconia ceramic surface treatment, because it can increase the esthetic of zirconia ceramics compared with polishing and reduce the wear of steatite ceramics compared with glazing.

Craniofacial therapy: advanced local therapies from nano-engineered titanium implants to treat craniofacial conditions / 国际口腔科学杂志·英文版

Nano-engineering-based tissue regeneration and local therapeutic delivery strategies show significant potential to reduce the health and economic burden associated with craniofacial defects, including traumas and tumours. Critical to the success of such nano-engineered non-resorbable craniofacial implants include load-bearing functioning and survival in complex local trauma conditions. Further, race to invade between multiple cells and pathogens is an important criterion that dictates the fate of the implant. In this pioneering review, we compare the therapeutic efficacy of nano-engineered titanium-based craniofacial implants towards maximised local therapy addressing bone formation/resorption, soft-tissue integration, bacterial infection and cancers/tumours. We present the various strategies to engineer titanium-based craniofacial implants in the macro-, micro- and nano-scales, using topographical, chemical, electrochemical, biological and therapeutic modifications. A particular focus is electrochemically anodised titanium implants with controlled nanotopographies that enable tailored and enhanced bioactivity and local therapeutic release. Next, we review the clinical translation challenges associated with such implants. This review will inform the readers of the latest developments and challenges related to therapeutic nano-engineered craniofacial implants.

Influence of antimicrobial peptide biofunctionalized TiO2 nanotubes on the biological behavior of human keratinocytes and its antibacterial effect / 中华口腔医学杂志

Objective: To fabricate TiO2 nanotube material functionalized by antimicrobial peptide LL-37, and to explore its effects on biological behaviors such as adhesion and migration of human keratinocytes (HaCaT) and its antibacterial properties. Methods: The TiO2 nanotube array (NT) was constructed on the surface of polished titanium (PT) by anodization, and the antimicrobial peptide LL-37 was loaded on the surface of TiO2 nanotube (LL-37/NT) by physical adsorption. Three samples were selected by simple random sampling in each group. Surface morphology, roughness, hydrophilicity and release characteristics of LL-37 of the samples were analyzed with a field emission scanning electron microscope, an atomic force microscope, a contact angle measuring device and a microplate absorbance reader. HaCaT cells were respectively cultured on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of cell was observed by field emission scanning electron microscope. The number of cell adhesion was observed by cellular immunofluorescence staining. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Wound scratch assay was used to observe the migration of HaCaT. The above experiments were used to evaluate the effect of each group on the biological behavior of HaCaT cells. To evaluate their antibacterial effects, Porphyromonas gingivalis (Pg) was respectively inoculated on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of bacteria was observed by field emission scanning electron microscope. Bacterial viability was determined by live/dead bacterial staining. Results: A uniform array of nanotubes could be seen on the surface of titanium samples in LL-37/NT group, and the top of the tube was covered with granular LL-37. Compared with PT group [the roughness was (2.30±0.18) nm, the contact angle was 71.8°±1.7°], the roughness [(20.40±3.10) and (19.10±4.11) nm] and hydrophilicity (the contact angles were 22.4°±3.1° and 25.3°±2.2°, respectively) of titanium samples increased in NT and LL-37/NT group (P<0.001). The results of in vitro release test showed that the release of antimicrobial peptide LL-37 was characterized by early sudden release (1-4 h) and long-term (1-7 d) slow release. With the immunofluorescence, more cell attachment was found on NT and LL-37/NT than that on PT at the first 0.5 and 2.0 h of culture (P<0.05). The results of CCK-8 showed that there was no significant difference in the proliferation of cells among groups at 1, 3 and 5 days after culture. Wound scratch assay showed that compared with PT and NT group, the cell moved fastest on the surface of titanium samples in LL-37/NT group at 24 h of culture [(96.4±4.9)%] (F=35.55, P<0.001). A monolayer cells could be formed and filled with the scratch in 24 h at LL-37/NT group. The results of bacterial test in vitro showed that compared with the PT group, the bacterial morphology in the NT and LL-37/NT groups was significantly wrinkled, and obvious bacterial rupture could be seen on the surface of titanium samples in LL-37/NT group. The results of bacteria staining showed that the green fluorescence intensity of titanium samples in LL-37/NT group was the lowest in all groups (F=66.54,P<0.001). Conclusions: LL-37/NT is beneficial to the adhesion and migration of HaCaT cells and has excellent antibacterial properties, this provides a new strategy for the optimal design of implant neck materials.

Effect of graphene-oxide-modified osteon-like concentric microgrooved surface on the osteoclastic differentiation of macrophages / 华西口腔医学杂志

OBJECTIVES@#This study aimed to investigate the effect of new biomimetic micro/nano surfaces on the osteoclastic differentiation of RAW264.7 macrophages by simulating natural osteons for the design of concentric circular structures and modifying graphene oxide (GO).@*METHODS@#The groups were divided into smooth titanium surface group (SS), concentric microgrooved titanium surface group (CMS), and microgroove modified with GO group (GO-CMS). The physicochemical properties of the material surfaces were studied using scanning electron microscopy (SEM), contact-angle measurement, atomic force microscopy, X-ray photoelectron spectroscopy analysis, and Raman spectroscopy. The effect of the modified material surface on the cell biological behavior of RAW264.7 was investigated by cell-activity assay, SEM, and laser confocal microscopy. The effect on the osteoclastic differentiation of macrophages was investiga-ted by tartrate-resistant acid phosphatase (TRAP) immunofluorescence staining and quantitative real-time polymerase chain reaction (qRT-PCR) experiments.@*RESULTS@#Macrophages were arranged in concentric circles along the microgrooves, and after modification with GO, the oxygen-containing groups on the surface of the material increased and hydrophilicity increased. Osteoclasts in the GO-CMS group were small in size and number and had the lowest TRAP expression. Although it promoted the proliferation of macrophages in the GO-CMS group, the expression of osteoclastic differentiation-related genes was lower than that in the SS group, and the difference was statistically significant (P<0.05).@*CONCLUSIONS@#Concentric circular microgrooves restricted the fusion of osteoclasts and the formation of sealing zones. Osteomimetic concentric microgrooves modified with GO inhibited the osteoclastic differentiation of RAW 264.7 macrophages.

Effects of thermal cycling on bonding properties of novel low-shrinkage resin adhesive / 华西口腔医学杂志

OBJECTIVES@#The current study aimed to investigate the bonding properties of a novel low-shrinkage resin adhesive containing expanding monomer and epoxy resin monomer after thermal cycling aging treatment.@*METHODS@#Expanding monomer of 3,9-diethyl-3,9-dimethylol-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU) as an anti-shrinkage additive and unsaturated epoxy monomer of diallyl bisphenol A diglycidyl ether (DBDE) as a coupling agent were synthesized. A blend of DDTU and DBDE at a mass ratio of 1∶1, referred to as "UE", was added into the resin matrix at the mass fraction of 20% to prepare a novel low-shrinkage resin adhesive.Then, the methacrylate resin adhesive without UE was used as the blank control group, and a commercial resin adhesive system was selected as the commercial control group. Moreover, the resin-dentin bonding and micro-leakage testing specimens were prepared for the thermal cycling aging treatment. The bonding strength was tested, the fracture modes were calculated, the bonding fracture surface was observed by scanning electron microscope (SEM), and the dye penetration was used to evaluate the tooth-restoration marginal interface micro-leakage. All the data were analyzed statistically.@*RESULTS@#After aging, the dentin bonding strength of the experimental group was (19.20±1.03) MPa without a significant decrease (P>0.05), that of the blank control group was (11.22±1.48) MPa with a significant decrease (P<0.05) and that of the commercial control group was (19.16±1.68) MPa without a significant decrease (P>0.05). The interface fracture was observed as the main fracture mode in each group after thermal cycling by SEM. The fractured bonding surfaces of the experimental group often occurred on the top of the hybrid layer, whereas those of the blank and commercial control groups mostly occurred on the bottom of the hybrid layer. Micro-leakage rating counts of specimens before and after thermal cycling were as follows: the experimental group was primarily 0 grade, thereby indicating that a relatively ideal marginal sealing effect could be achieved (P>0.05); meanwhile, the blank control group was primarily 1 grade, and the penetration depth of dye significantly increased after thermal cycling (P<0.05); the commercial control group was primarily 0 grade without statistical difference before and after thermal cycling (P>0.05), while a significant difference was observed between the commercial control group and experimental group after thermal cycling (P<0.05).@*CONCLUSIONS@#The novel low-shrinkage resin adhesive containing 20%UE exhibited excellent bonding properties even after thermal cycling aging treatment, thereby showing a promising prospect for dental application.

In vitro research of oral microscope-assisted implant surface decontamination / 华西口腔医学杂志

OBJECTIVES@#To investigate the effect of oral microscope-assisted surface decontamination on implants in vitro.@*METHODS@#Twelve implants that fell off because of severe peri-implantitis were collected, and decontamination was carried out on the surfaces of implants through curetting, ultrasound, titanium brushing, and sandblasting at 1×, 8×, or 12.8× magnifications. The number and sizes of residues on the implants' surfaces after decontamination were determined, and the decontamination effect was analyzed according to the thread spacing in the different parts of the thread.@*RESULTS@#1) The 8× and 12.8× groups scored lower for implant surface residues than the 1× group (P<0.000 1), and the 12.8× group scored lower than the 8× group (P<0.001); 2) no difference in residue score was found between the wide and narrow thread pitch (P>0.05), and the 8× and 12.8× groups had lower scores than the 1× group (P<0.001); 3) the lowest number of contaminants was observed at the tip of the thread, whereas the highest was observed below the thread, and the difference was significant (P<0.001). However, the thread pitch had no effect on the number of contaminants in different areas (P>0.05); 4) the residue scores of the 8× and 12.8× groups were lower than those of the 1× group at the thread tip and above, sag, and below the thread of the implants (P<0.05).@*CONCLUSIONS@#Residues on the surfaces of contaminated implants can be effectively removed by using an oral microscope. After decontamination, the residues of pollutants were mainly concentrated below the thread of the implants, and the thread pitch of the implants had no significant effect on the residues.

Progress in Application of Heparin Coating in Blood Contact Medical Devices / 中国医疗器械杂志

Blood compatibility is the main restriction of blood-contacting medical devices in clinical application, especially long-term blood-contacting medical devices will stimulate the immune defense mechanism of the host, resulting in thrombosis. Heparin anticoagulant coating links heparin molecules to the surface of medical device product materials, improves the compatibility between the material surface interface and the body, and reduces the host immune defense reactions. This study reviews the structure and biological properties of heparin, the market application status of heparin-coated medical products, the insufficiency and improvement of heparin coating, which can provide a reference for the application research of blood contact medical devices.

Micromechanical interlocking structure at the filler/resin interface for dental composites: a review / 国际口腔科学杂志·英文版

Dental resin composites (DRCs) are popular materials for repairing caries or dental defect, requiring excellent properties to cope with the complex oral environment. Filler/resin interface interaction has a significant impact on the physicochemical/biological properties and service life of DRCs. Various chemical and physical modification methods on filler/resin interface have been introduced and studied, and the physical micromechanical interlocking caused by the modification of fillers morphology and structure is a promising method. This paper firstly introduces the composition and development of DRCs, then reviews the chemical and physical modification methods of the filler/resin interface, mainly discusses the interface micromechanical interlocking structures and their enhancement mechanism for DRCs, finally give a summary on the existing problems and development potential.

Progress in antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants / 中国修复重建外科杂志

OBJECTIVE@#To review antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants, so as to provide reference for subsequent research.@*METHODS@#The related research literature on antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants in recent years was reviewed, and the research progress was summarized based on different kinds of antibacterial substances and osteogenic active substances.@*RESULTS@#At present, the antibacterial/osteogenesis dual-functional surface modification strategy of titanium-based implants includes: ① Combined coating strategy of antibiotics and osteogenic active substances. It is characterized in that antibiotics can be directly released around titanium-based implants, which can improve the bioavailability of drugs and reduce systemic toxicity. ② Combined coating strategy of antimicrobial peptides and osteogenic active substances. The antibacterial peptides have a wide antibacterial spectrum, and bacteria are not easy to produce drug resistance to them. ③ Combined coating strategy of inorganic antibacterial agent and osteogenic active substances. Metal ions or metal nanoparticles antibacterial agents have broad-spectrum antibacterial properties and various antibacterial mechanisms, but their high-dose application usually has cytotoxicity, so they are often combined with substances that osteogenic activity to reduce or eliminate cytotoxicity. In addition, inorganic coatings such as silicon nitride, calcium silicate, and graphene also have good antibacterial and osteogenic properties. ④ Combined coating strategy of metal organic frameworks/osteogenic active substances. The high specific surface area and porosity of metal organic frameworks can effectively package and transport antibacterial substances and bioactive molecules. ⑤ Combined coating strategy of organic substances/osteogenic active substancecs. Quaternary ammonium compounds, polyethylene glycol, N-haloamine, and other organic compounds have good antibacterial properties, and are often combined with hydroxyapatite and other substances that osteogenic activity.@*CONCLUSION@#The factors that affect the antibacterial and osteogenesis properties of titanium-based implants mainly include the structure and types of antibacterial substances, the structure and types of osteogenesis substances, and the coating process. At present, there is a lack of clinical verification of various strategies for antibacterial/osteogenesis dual-functional surface modification of titanium-based implants. The optimal combination, ratio, dose-effect mechanism, and corresponding coating preparation process of antibacterial substances and bone-active substances are needed to be constantly studied and improved.

Influence of pH-cycling and abrasion wear on the mechanical properties of conventional and bulk fill resin composites

The objective of this study was to evaluate the effect of abrasion wear on surface roughness and microhardness of different commercially available resin composites simulating pH-challenges of the oral cavity. Methods: Three resin composites (RC) were used in this study: one conventional: Z250; and two bulk fill resin composites (BRC): Tetric N-Ceram (TNC) and Sonic Fill (SF). The RC was inserted in a prefabricated mold (15mm wide x 4mm thickness) in two layers, or in a single layer for BRC. Thirty samples were prepared and surface roughness (Ra) and Knoop microhardness (KHN) test were performed at three different time-points of evaluation: baseline (24h after sample preparation); partial (after pH cycling); and final (after simulated toothbrushing procedure). Two samples of each group were selected after different treatments and analyzed descriptively on a scanning electron microscopy (SEM). Data from Ra and KHN were analyzed by two-way repeated-measures ANOVA and Bonferroni's post-hoc test with a significance level set at 5%. Results: Ra increased for all groups (p<0.001), at the final time-point, Z250 and TNC groups present the highest values. Oppositely, KHN decreased for all groups (p<0.001), Z250 group showed the highest KHN values for all time-points (p<0.001). The SEM imagens showed a regular surface for samples cycled and irregular with inorganic particles exposed for samples toothbrushed. Conclusion: pH-cycling and simulated toothbrushing affected the superficial properties (roughness and Knoop microhardness), as observed at SEM imagens, with irregular surface with inorganic particles exposure

Effect of laboratory and chairside polishing methods on the surface topography of occlusal splint materials manufactured using conventional, subtractive and additive digital technologies / Efeito de métodos de polimento em laboratório e em consultório na topografia de superfície de materiais de splint oclusal fabricados usando tecnologias digitais convencionais, subtrativas e aditivas

Objetivo: Este estudo avaliou as propriedades de polimento dos materiais de splint oclusal obtidos usando métodos de fabricação subtrativos e aditivos com os procedimentos de polimento laboratorial (LP) e polimento em consultório (CP). Material e Métodos: As amostras (N=180, n=60 para cada grupo) foram fabricadas usando um dos seguintes métodos: método de fabricação subtrativo (SMM) (M-PM Disc, Merz Dental GmbH), método de fabricação aditivo (AMM) (Freeprint Splint 2.0, DETAX GmbH & Co. KG) e o método de fabricação convencional (CMM) (Promolux HC, Merz Dental GmbH). Seguindo os procedimentos de LP e CP, a rugosidade da superfície dos espécimes foi medida usando um perfilômetro de superfície digital. Um espécime representativo foi selecionado de cada grupo, e uma imagem de microscópio eletrônico de varredura (SEM) foi obtida. Resultados: Tanto o método de fabricação quanto os procedimentos de polimento afetaram significativamente os resultados (P<0,01). Os termos de interação também foram significativos (P<0,001). Conclusão: Com ambos os métodos de polimento, a rugosidade superficial do grupo AMM foi a maior e a do grupo CMM a menor. Embora o procedimento CP tenha sido mais eficaz do que LP com ambos os métodos, a rugosidade da superfície ficou abaixo do limite de 0,2 µm após ambos os procedimentos de polimento testados (AU)

Objective: This study evaluated the polishing properties of the occlusal splint materials obtained using subtractive and additive manufacturing methods with the laboratory-type polishing (LP) and chairside-type polishing (CP) procedures. Material and Methods: Specimens (N=180, n=60 each group) were manufactured using one of the following methods: subtractive manufacturing method (SMM) (M-PM Disc, Merz Dental GmbH), additive manufacturing method (AMM) (Freeprint Splint 2.0, DETAX GmbH & Co. KG), and the conventional manufacturing method (CMM) (Promolux HC, Merz Dental GmbH). Following LP and CP procedures, surface roughness of the specimens was measured using a digital surface profilometer. One representative specimen was selected from each group, and a scanning electron microscope (SEM) image was made. Results: Both the manufacturing method and the polishing procedures significantly affected the results (P<0.01). Interaction terms were also significant (P<0.001). Conclusion: With both polishing methods, surface roughness of the AMM group was the highest and the CMM group the least. Although the CP procedure was more effective than LP with both methods, surface roughness was below the 0.2 µm threshold after both polishing procedures tested. (AU)