Effects of different debridement methods on titanium surfaces in vitro / 口腔疾病防治

Objective @#To investigate the effect of different decontamination methods, including photodynamic therapy, sandblasting and titanium curette, on titanium surface morphology and bacterial adhesion for the treatment of peri-implant disease. @*Methods@#Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) were inoculated on the surface of polished titanium specimens, and titanium specimen surfaces were treated with different decontamination methods after incubation. The titanium specimens were divided into a no-treatment control group, photodynamic group, sandblasting group and titanium curette group according to different decontamination methods. The changes in titanium surface roughness were observed by atomic force microscopy (AFM), and the remaining bacteria on the titanium surface were observed by scanning electron microscopy (SEM) and live/dead bacteria staining tests. After reinoculation of Pg and Fn, bacterial readhesion was observed on the surface of decontaminated titanium specimens. @*Results @#The AFM results showed that the surface roughness of the titanium curette group was significantly higher than that of the no-treatment control group, photodynamic group and sandblasting group (P<0.05), and there was no statistically significant difference between the no-treatment control group, photodynamic group and sandblasting group (P>0.05). The results of contact angle measurement showed that the surface contact angle of each treatment group was smaller than that of the no-treatment control group (P<0.05). The SEM results obtained after the titanium specimen surface was decontaminated showed that the number of bacteria on the no-treatment control group surface was higher and the bacteria were relatively concentrated. The bacteria on the surface of the photodynamic group, sandblasting group and titanium curette group were scattered and distributed in small numbers, and most bacteria on the surface of the photodynamic group were ruptured. The results of the live/dead bacteria staining experiment showed that the percentage of dead bacteria on the surface of the photodynamic group was significantly higher than that of the no-treatment control group, sandblasting group and titanium curette group (P<0.05). The remaining bacteria on the surface of the sandblasting group and titanium curette groups were mainly live bacteria. The remaining bacterial adhesion on the surface was significantly reduced for the sandblasting group compared to the no-treatment control group and the photodynamic and titanium curette groups (P<0.05). SEM and live/dead bacteria staining results of bacterial readhesion on the surface of titanium specimens showed that there was an aggregation of Pg on the surface of the titanium curette group, and its surface bacterial adhesion was significantly higher than that of the no-treatment control group, photodynamic group and sandblasting group. @*Conclusion @#In mechanical decontamination, sandblasting machines are a better option than photodynamic therapy and titanium curettes; however, sandblasting does not remove all bacterial contamination. For sterilization, photodynamic therapy is more effective than sandblasting and titanium curettes. A combination of sandblasting and photodynamic therapy methods for the treatment of peri-implant disease may be considered in clinical practice.

Survival rate and stability of surface-treated and non-surface-treated orthodontic mini-implants: a randomized clinical trial

ABSTRACT Objectives: This clinical trial was conducted to evaluate the stability and failure rate of surface-treated orthodontic mini-implants and determine whether they differ from those of non-surface-treated orthodontic mini-implants. Trial Design: Randomized clinical trial with a split-mouth study design. Setting: Department of Orthodontics, SRM Dental College, Chennai. Participants: Patients who required orthodontic mini-implants for anterior retraction in both arches. Methods: Self-drilling, tapered, titanium orthodontic mini-implants with and without surface treatment were placed in each patient following a split-mouth design. The maximum insertion and removal torques were measured for each implant using a digital torque driver. The failure rates were calculated for each type of mini-implant. Results: The mean maximum insertion torque was 17.9 ± 5.6 Ncm for surface-treated mini-implants and 16.4 ± 9.0 Ncm for non-surface-treated mini-implants. The mean maximum removal torque was 8.1 ± 2.9 Ncm for surface-treated mini-implants and 3.3 ± 1.9 Ncm for non-surface-treated mini-implants. Among the failed implants, 71.4% were non-surface-treated mini-implants and 28.6% were surface-treated mini-implants. Conclusion: The insertion torque and failure rate did not differ significantly between the groups, whereas the removal torque was significantly higher in the surface-treated group. Thus, surface treatment using sandblasting and acid etching may improve the secondary stability of self-drilling orthodontic mini-implants. Trial registration: The trial was registered in the Clinical Trials Registry, India (ICMR NIMS). Registration number: CTRI/2019/10/021718

RESUMO Objetivos: Este ensaio clínico foi conduzido para avaliar a estabilidade e a taxa de falha de mini-implantes ortodônticos com superfície tratada, e determinar se elas diferem das dos mini-implantes ortodônticos sem superfície tratada. Desenho do estudo: Ensaio clínico randomizado com desenho de boca dividida. Instituição: Department of Orthodontics, SRM Dental College, Chennai/India. Participantes: Pacientes que necessitavam de mini-implantes ortodônticos para retração anterior em ambas as arcadas. Métodos: Mini-implantes ortodônticos autoperfurantes, cônicos, de titânio com ou sem tratamento de superfície, foram colocados em cada paciente, seguindo um desenho de boca dividida. Os torques máximos de inserção e de remoção foram medidos para cada mini-implante, usando um torquímetro digital. As taxas de falha foram calculadas para cada tipo de mini-implante. Resultados: O valor médio do torque máximo de inserção foi de 17,9 ± 5,6 Ncm para mini-implantes com superfície tratada e 16,4 ± 9,0 Ncm para mini-implantes sem superfície tratada. O valor médio do torque máximo de remoção foi de 8,1 ± 2,9 Ncm para mini-implantes com superfície tratada e 3,3 ± 1,9 Ncm para mini-implantes sem superfície tratada. Entre os implantes que falharam, 71,4% eram mini-implantes sem superfície tratada e 28,6% eram mini-implantes com superfície tratada. Conclusão: O torque de inserção e a taxa de falha não diferiram significativamente entre os grupos; porém, o torque de remoção foi significativamente maior no grupo com superfície tratada. Assim, o tratamento de superfície com jateamento e condicionamento ácido pode melhorar a estabilidade secundária dos mini-implantes ortodônticos autoperfurantes. Registro do estudo: Esse estudo foi registrado no Clinical Trials Registry, Índia (ICMR NIMS). Número de registro: CTRI/2019/10/021718

Evaluation of short- and long-term bond strength of zirconia after different surface treatments / Avaliação da resistência de adesão de curto e longo prazo de zircônia após diferentes tratamentos de superfície

Objective: The aim of the study was to evaluate the short and long-term effects of different surface treatments on the bond strengths of zirconia. Material and Methods: 225 blocks of sintered zirconia samples (4 x 4 x 3 mm) were divided into five groups and subjected to different surface treatments: control group (without surface treatment), alumina group (sandblasting [25-µm-aluminum-oxide]), alumina+Ambar Universal-APS (AU) group, CoJet group (silica-coated [30-µm silica-modified aluminum particles]), and CoJet+AU group. Subsequently, zirconia samples were cemented against resin samples (total dimensions: 8x8x6mm) and assigned to three storage conditions: dry, humid (artificial saliva at 37°C for 30-days) or thermocycling [100.000-cycles] (n=15 per group). The microtensile bond strength (µTBS) was determined using a universal testing machine. The failure modes were observed and analyzed using a stereomicroscope. Normality tests, descriptive statistics, and two-way ANOVA, followed by post-hoc comparisons, were performed to evaluate the effect of surface treatments and storage conditions on µTBS (α=0.05). Results: µTBS was influenced by surface treatment in the short and long-term (P<0.0001). The highest values were found in CoJet+AU in dry (33.51 ±2.48 MPa), humid (32.87 ±2.68 MPa) and thermocycling (21.37 ±1.68 MPa) storage conditions compared with others. Interestingly, no significant differences in µTBS were found among alum +AU and CoJet alone under any of the three storage conditions. Adhesive failure increased in all groups after thermocycling, but CoJet+AU had the lowest values of adhesive failure compared with others. Conclusion: The combination of CoJet and Ambar universal as a surface treatment for zirconia specimens provides significantly higher short and long-term bond strengths of adhesive cementation (AU)

Objetivo: O objetivo do estudo foi avaliar os efeitos de curto e longo prazo de diferentes tratamentos de superfície na resistência de adesão da zircônia. Material e Métodos: 225 blocos de amostras de zircônia sinterizada (4 x 4 x 3 mm) foram divididos em cinco grupos e submetidos a diferentes tratamentos de superfície: grupo controle (sem tratamento de superfície), grupo de alumina (jateamento de 25 µm de óxido de alumínio), grupo alumina+Ambar Universal-APS (AU), grupo CoJet (partículas de alumínio modificadas por sílica de 30 µm), e grupo CoJet+AU. Posteriormente, as amostras de zircônia foram cimentadas em amostras de resina (dimensões totais: 8x8x6mm) e designadas para três condições de armazenamento: seco, úmido (saliva artificial a 37°C por 30 dias) ou ciclagem térmica (100.000 ciclos) (n=15 por grupo). A resistência de adesão de microtensão (µTBS) foi determinada usando uma máquina de teste universal. Os modos de falha foram observados e analisados usando um estereomicroscópio. Testes de normalidade, estatísticas descritivas e ANOVA de duas vias, seguidas de comparações pos-hoc, foram realizados para avaliar o efeito dos tratamentos de superfície e das condições de armazenamento na µTBS (α=0.05). Resultados: A µTBS foi influenciada pelo tratamento de superfície a curto e longo prazo (P<0.0001). Os valores mais altos foram encontrados em CoJet+AU nas condições de armazenamento a seco (33.51 ±2.48 MPa), úmido (32.87 ±2.68 MPa) e ciclagem térmica (21.37 ±1.68 MPa) em comparação com os outros. Curiosamente, não foram encontradas diferenças significativas na µTBS entre alum +AU e CoJet sozinho em nenhuma das três condições de armazenamento. A falha adesiva aumentou em todos os grupos após a ciclagem térmica, mas CoJet+AU teve os valores mais baixos de falha adesiva em comparação com os outros. Conclusão: A combinação de CoJet e Ambar Universal como tratamento de superfície para espécimes de zircônia proporciona resistências de adesão significativamente mais altas a curto e longo prazo para cimentação adesiva. (AU)

Various surface treatment methods and resin cement type on the influence of bonding strength of zirconia ceramics / 中国组织工程研究

BACKGROUND: Due to the stability of the physical and chemical properties of zirconia ceramics, its poor adhesiveness has seriously affected the clinical application of zirconia ceramic prosthesis. OBJECTIVE: To analyze the effect of different surface treatment methods and resin cement on the bonding strength of zirconia ceramics. METHODS: Totally 240 zirconia blocks were randomly divided into 16 groups, with 15 in each group. In group A, the treatment method was sandblasting+hydrofluoric acid+Monobond-s+Panavia F 2.0. In group B, the treatment method was sandblasting+hydrofluoric acid+Monobond-s+Perma CemDual. In group C, the treatment method was sandblasting+hydrofluoric acid+new silane coupling agent+Panavia F 2.0. In group D, the treatment method was sandblasting+hydrofluoric acid+new silane coupling agent+Perma Cem-Dual. In group E, the treatment method was sandblasting+Monobond-s+Panavia F 2.0. In group F, the treatment method was sandblasting+Monobond-s+Perma Cem-Dual. In group G, the treatment method was sandblasting+Monobond-s+Panavia F 2.0 resin cement binder. In group H, the treatment method was sandblasting+new silane coupling agent+Perma Cem-Dual. In group I, the treatment method was hydrofluoric acid+Monobond-s+Panavia F 2.0. In group J, the treatment method was hydrofluoric acid+Monobond-s+Perma Cem-Dual. In group K, the treatment method was hydrofluoric acid+new silane coupling agent+Panavia F 2.0. In group L, the treatment method was hydrofluoric acid+new silane coupling agent+Perma Cem-Dual. In group M, the treatment method was Monobond-s+Panavia F 2.0. In group N, the treatment method was Monobond-s+Perma CemDual. In group O, the treatment method was new silane coupling agent+Panavia F 2.0. In group P, the treatment method was new silane coupling agent+Perma Cem-Dual. Panavia F 2.0 and Perma Cem-Dual were resin cement binders. Monobond-s was commercial silane coupling agent. The bonding strength of each group was tested. RESULTS AND CONCLUSION: (1) The bonding strength of groups C, G and H was higher than that of the remaining 13 groups (P < 0.05). The bonding strength of groups A, B, C, D, E, F, G and H was higher than that of groups I, J, K, L, M, N, and P (P < 0.05). (2) The results show that the combined use of zirconia sandblasting and new silane coupling agent can significantly improve the bonding strength of ceramic-cement. Hydrofluoric acid pretreatment is ineffective. The different types of cement will have a certain effect on the bonding strength.

Effect of different treatments of highly translucent zirconia on the bonding strength between zirconia and veneering porcelain / 口腔疾病防治

Objective @# To evaluate the effect of different surface treatments on the bonding strength between highly translucent zirconia and veneering porcelain and to provide a research basis for improving the zirconium porcelain bond strength between zirconium and ceramic material.@*Methods @# Thirty cylindrical zirconia blocks with 10-mm diameter and 10-mm height were prepared and divided into four groups (n=7), labeled as control group (C), sandblasting group (S), bonding group (B), and sandblasting and bonding group (SB). The surface morphology of zirconia before and after sandblasting was observed in the remaining two specimens. Group C was veneered (2 mm in height and 5 mm in diameter) with porcelain powder by layering after grinding. Group S was sandblasted after grinding. Group B was veneered with a thin layer of porcelain powder as bond coating. Group SB was sandblasted and veneered with a thin layer of porcelain powder. After sintering, the shear specimens were embedded, and a shear bond strength test was conducted. Statistical analysis was conducted to analyze the data. Fracture surface analysis was also performed to determine the failure modes by stereomicroscopy.@*Results @# The bonding strength of group C was 21.86 ± 3.18 MPa. For group S, it was 22.12 ± 3.06 MPa. For group B, it was 19.19 ± 1.46 MPa. Finally, for group SB, it was 27.76 ± 1.95 MPa. There was no significant difference in shear strength between group C, group S and group B. There was a significant difference in shear strength between each group and group SB (P < 0.05). Under a stereomicroscope, the observed fracture modes of each group were mainly mixed failure.@*Conclusion@#Sandblasting cannot significantly increase the bonding strength between zirconia and veneering porcelain. Veneering with a thin layer of porcelain powder as the bond coating has no obvious effect on the bonding strength. Sandblasting and veneering with a thin layer of porcelain powder as a bond coating can significantly improve the bonding strength between zirconia and veneering porcelain.

To Evaluate the Shear Bond Strength of Bondable Molar Tubes by Two Enamel Conditioning Techniques

Shear Bond Strength (SBS) is considered to be the main factor in the evolution of bonding. The bracket bond strength should withstand the forces during the orthodontic tooth movement. The commonly used technique by Orthodontists is to attach the brackets to the enamel surface is the acid-etch bonding technique along with 37 % phosphoric acid as etchant. With time, a new technique emerged in orthodontics which is used before bonding for the primary preparation of teeth as well as for the purpose of increasing bond strength known as Sandblasting. This study was done to compare the shear bond strength of acid etching and air abrasion technique used in orthodontic practice. MethodsA total of 100 extracted human first molar teeth were selected and segregated into 4 groups of 25 teeth. Group I: bonding without enamel preparation, Group II: using acid etching with 37 % phosphoric acid, Group III - sandblasting with 50 μ aluminium oxide, Group IV - sandblasting with 100 μ aluminium oxide. These 100 samples were then subjected to the measurement of the shear bond strength with an Instron machine and was measured in Newtons. ResultsGroup 1 showed a mean shear bond strength of 7.21 ± 0.29; for group II it was 7.77 ± 0.53; for group III it was 8.3 ± 0.3 and for group IV it was 10.04 ± 0.45. Groups 2 and 3 and groups 2 and 4 showed statistically significant difference. Shear bond strengths of both the groups 3 and 4 showed highly statistically significant difference. Conclusions100 µ aluminium oxide group showed the highest Shear Bond Strength. On inter group comparison, sandblasting with aluminium oxide was found to have better shear bond strength compared to conventional acid etching techniques.

Effect of glass-infiltration treatments on the shear bond strength between zirconia and ultra low-fusing porcelain veneer / 대한치과보철학회지

PURPOSE: This study examined the effects of glass infiltration treatments on the shear bond strength (SBS) between zirconia core and ultra low-fusing porcelain veneer. MATERIALS AND METHODS: The zirconia specimens were classified into 4 groups (n = 12): Untreated zirconia (group Z), zirconia coated ZirLiner (group ZL), glass-infiltrated zirconia (group ZG), glass-infiltrated and sandblasted zirconia (group ZGS). A cylinder of ultra low-fusing veneer porcelain was build up on each disk (6 mm × 3 mm). SBS was measured using a universal testing machine. Scanning electron microscope and Energy Dispersive X-ray spectroscopy were used to evaluate the surface of zirconia and failure pattern after SBS. RESULTS: SBS value of group ZGS was significantly lower than that of other groups (P < .05). No significant differences were detected among group ZL, group Z and group ZG. CONCLUSION: Glass infiltration is not effective to the bond strength between zirconia and ultra low-fusing porcelain veneer. Sandblasting also dramatically decreased the bonding strength.

Effect of several repair techniques on the bond strength between composite resin and degraded Y-TZP ceramic / Efeito de várias técnicas de reparo na resistência de união entre resina composta e zircônia degradada

Objective: To evaluate the bond strength of different repair treatments for composite resin to aged Y-TZP ceramics. Material and Methods: Zirconia blocks were cut into smaller specimens, sintered according to manufacturer's recommendations (final dimensions of 4×4×3 mm), and randomly allocated into nine groups (n=15) according to the surface treatment and presence/ absence of aging of the substrate (subjected to lowtemperature degradation - LTD), as follows: without LTD (Control: without treatment; TBS: tribochemical silica coating + silane + adhesive); with LTD (Control-LTD: without treatment; TBS-LTD: TBS with hydrothermal degradation; MoS-LTD: Monobond S + adhesive; MoPLTD: Monobond Plus + adhesive; MZP-LTD: Metal/ Zirconia Primer + adhesive; USB-LTD: Single Bond Universal; AP-LTD: Alloy primer + adhesive). LTD was simulated in an autoclave (134 °C, 2 bar, 5 h). The ceramic blocks were embedded in PVC cylinders with a self-curing acrylic resin; each surface treatment protocol was performed; a composite resin cylinder ( : 3.25 mm and height: 3 mm) was then build-up using split metallic matrices. All the specimens were aged (thermocycling + storage in water for 90 days) and subjected to the shear bond strength test using a universal testing machine (1 mm/min). The failure mode was classified into four types: adhesive, composite resin cohesive fracture, ceramic cohesive fracture, and mixed. The bond strength values were subjected to Mann­Whitney test. Results: Only air-abraded samples (TBS and TBS­LTD) survived thermocycling. More than 80% of the samples of the other groups presented pre-test failures. TBS groups presented higher values of bond strength (3.94) compared to TBSLTD (0.96). The predominant type of failure for the surviving samples were adhesive. Conclusion: Air particle abrasion is mandatory to improve the bond strength of the Y-TZP substrate; an aged substrate presents an even more unfavorable scenario for adhesion. (AU)

Objetivo: Avaliar a resistência de união ao cisalhamento gerada por diferentes técnicas de reparo em resina composta aderida em zircônia envelhecida (sujeita a degradação a baixa temperatura - LTD). Material e Métodos: blocos de zircônia foram seccionados em espécimes, sinterizados de acordo com o fabricante (dimensões finais de 4x4x3 mm), e aleatorizados em nove grupos (n=15) de acordo com o tratamento de superfície e presença/ausência de envelhecimento do substrato (LTD), conforme: sem LTD (Control: sem tratamento; TBS: tribosilicatização + silano + adesivo); com LTD (Control-LTD: Monobond S + adesivo; MoP-LTD: Monobond plus + adesivo; MZPLTD: Meta/Zirconia primer + adesivo). LTD foi simulada em autoclave (134 °C, 2 bar, 5 h). Os blocos de cerâmica foram embutidos em cilindros de PVC com resina acrílica autopolimerizável; cada tratamento de superfície foi realizado; um cilindro de resina composta ( : 3,25 mm 3 mm de altura) foi confeccionado usando matrizes metálicas bipartidas. Todos os espécimes foram envelhecidos (termociclagem + armazenagem em água por 90 dias) e sujeitos ao teste de cisalhamento usando um equipamento de teste universal (1 mm/ min). O modo de falha foi classificado em quatro grupos: adesivo, fratura coesiva em resina composta, fratura coesiva da cerâmica, e mista. Os valores de adesão foram sujeitos ao teste de Mann-Whitney. Resultados: somente as amostras jateadas (TBS e TBSLTD) sobreviveram a termociclagem. Mais que 80% dos espécimes dos outros grupos apresentaram falhas préteste. Os grupos TBS apresentaram os maiores valores de resistência ao cisalhamento (3,94) comparado com TBS-LTD (0,96). Os tipos predominantes de falha para os espécimes sobreviventes foi adesiva. Conclusão: o jateamento é recomendável para aumentar a resistência adesiva à zircônia; um substrato envelhecido apresenta um cenário mais desfavorável de adesão. (AU)

Effect of different sandblasting conditions on the metal-ceramic bonding strength of Co-Cr alloy fabricated by selective laser melting technology / 华西口腔医学杂志

OBJECTIVE@#To investigate the effect of different sandblasting conditions on the metal-ceramic bonding strength of Co-Cr alloy fabricated by selective laser melting (SLM) technology.@*METHODS@#A total of 63 specimens of Co-Cr alloy fabricated by SLM were prepared and randomly divided into nine groups (n=7). Each group was treated with different powder particles (A1=50 µm, A2=100 µm, and A3=150 µm) and pressures (B1=0.2 MPa, B2=0.4 MPa, and B3=0.6 MPa) in sandblasting. One sample was randomly selected from each group for microstructure observation by scanning electron microscope (SEM). Ceramic was fired at the center of the specimens. Metal-ceramic bonding strength was measured with universal testing machine. Results were statistically analyzed with SPSS 17.0 software.@*RESULTS@#The mean bond strengths were as follows: Group A1B1: 27.22 MPa±0.95 MPa, Group A1B2: 27.58 MPa±0.47 MPa, Group A1B3: 26.80 MPa±0.71 MPa, Group A2B1: 27.54 MPa±0.78 MPa, Group A2B2: 30.75 MPa±0.43 MPa, Group A2B3: 26.93 MPa±0.88 MPa, Group A3B1: 28.18 MPa±0.93 MPa, Group A3B2: 29.55 MPa±0.57 MPa, and Group A3B3: 28.11 MPa±0.91 MPa. The particle factor of Al₂O₃ and the pressure factor of blasting showed statistical significance (P<0.05). An interaction was observed between the factors of particle and pressure (P<0.05). Mixed fracture mode of all specimens was observed after the shear strength test.@*CONCLUSIONS@#In conclusion, metal-ceramic bonding strength reaches the maximum when specimens are sandblasted with 100 µm alumina oxide at 0.4 MPa pressure.

The effect of glazing and aging on the surface properties of CAD/CAM resin blocks

PURPOSE: To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. MATERIALS AND METHODS: Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad Säckingen, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness (Ra and Rz) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post-hoc test (P .05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher Ra values than Group 2 (P .05). CONCLUSION: Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

Comparison of bond strengths of three kinds of metal bottom plate brackets before and after sandblasting and its significance / 吉林大学学报(医学版)

Objective: To discuss the bond strengths of three kinds of metal bottom plate brackets commonly used in clinic and after sandblasting treatment under the condition of artificial saliva, and to evaluate their bonding properties. Methods: A total of 60 premolar teeth extracted because of orthodontic treatment were collected and divided into domestic Xinya bracket group (Xinya group), imported ultra thin MBT bracket group (MBT group), and Japan TOMY lock bracket group (TOMY group) (n= 20). The teeth were randomly divided into six groups after the three types of brackets fall off. The three types of new and sandblasting brackets were respectively bonded to the teeth randomly with 10 brackets in each group. The shear strength was detected by universal electronic mechanical testing machine, and the adhesive remnant index (ARI) of enamel surface in each group was obsereved, and the morphological features of three different base brackets and three shedding of brackets conducted by sandblasting were obsereved by scanning electron microscope. Results: Under the condition of artificial saliva, for the first bonding and bonding again, the shear strengths of the new brackets in TOMY goup were higher than those in Xinya group and MBT group (P0. 05). For the brackets treated with sandblasting after shedding in three groups, the shear strength in TOMY group was greater than those in Xinya group and MBT group (P0. 05). The shear strengths of brackets that were conducted by sandblasting after falling off in TOMY group and MBT group were increased compared with the original brackets (P0. 05). The scanning electron microscope results showed that three kinds of brackets were crisscroped with the mesh, and they were more dense in TOMY group. After sandblasting, the sand grains were embedded in the grid, and the sand grains were more embedded in the inverted pits in TOMY group and MBT group. After sandblasting again, the sand particle embedding scope was increased, and the grid structure of the network bottom in Xinya group was destroyed, but there were no obvious abnormities in MBT group and TOMY group. Conclusion: The bond strengths of the three types of bottom plate brackets can meet the clinical needs, and the bond strength in TOMY group is superior to those in Xinya group and MBT group. The use of sandblasting to deal with the shedding of TOMY and MBT brackets can improve the bond strengths of the brackets.

Efecto de un tratamiento experimental de una superficie sobre la resistencia flexural en una zirconia Y-TZP / Effect of an experimental surface treatment on Y-TZP zirconia flexural strength

RESUMEN Objetivo: Analizar el efecto del microgranallado superficial como tratamiento experimental de regeneración, en la resistencia flexural y esfuerzos residuales de una Zirconia Y-TZP, una vez ha sido alterada con otros tratamientos mecánicos como microarenado y fresado. Métodos: Un total de 75 probetas de Zirconia Y-TZP fueron divididas en cinco grupos n=15 y sometidas a tratamientos de superficie así: fresado y microarenado (Grupos 2 y 4) microarenado + microgranallado y fresado + microgranallado (Grupos 3 y 5), y comparadas con un grupo control (Grupo 1), mediante Difracción de Rayos X (DRX), Microscopía electrónica de barrido (SEM), Microscopía confocal (CLSM) y sometida a falla en máquina universal de ensayos. Resultados: Los grupos de microgranallado y microarenado presentaron un aumento significativo de la resistencia flexural p=0.0082 con relación al grupo de fresado. Las mediciones mediante DRX no mostraron relación estadística con los cambios en la resistencia flexural. Significancia: Es posible que el microgranallado se considere un tratamiento para regenerar las propiedades mecánicas reducidas por fresado o arenado en la Zirconia Y-TZP.

ABSTRACT Objective: To analyze the effect of surface micro shot peening as an experimental regeneration treatment on the flexural strength and residual stresses of a Y-TZP Zirconia, once it has been altered with other mechanical treatments such as micro sandblasting and milling. Methods: A total of 75 Zirconia Y-TZP specimens were divided into five n = 15 groups and subjected to surface treatments such as: milling and micro sandblasting (Groups 2 and 4) micro sandblasting + micro shot peening; and milling + micro shot peening (Groups 3 and 5), compared to a control group (Group 1), by X-ray diffraction (XRD), scanning electron microscopy (SEM), confocal microscopy (CLSM) and subjected to failure in a universal testing machine. All the results were compared to find a statistical relationship between them using a mixed linear model and Tuckey. Results: The groups of micro shot peening and micro sandblasting presented a significant increase of the flexural strength p = 0.0082 vs the milling group. The XRD technique is not related to flexural strength measurements. Significance: It is possible that the micro shot peening be considered a treatment to regenerate the mechanical properties reduced by milling or sandblasting in Zirconia Y-TZP.

Effect of sandblasting on bending strength and subcritical crack growth of the dental zirconia ceramics / 中华口腔医学杂志

Objective@#To evaluate the effect of sandblasting on bending strength and subcritical crack growth (SCG) under cyclic loading of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics.@*Methods@#After being polished, sixty bar-shaped specimens of Y-TZP (Wieland zirconia ceramics) were assigned to two groups (n=30) according to the random number table, the sandblasting group (SG) which was treated with sandblasting and the control group (CG) which remained untouched. In each group, half of the specimens (n=15) were subjected to bending strength test, and the results were examined by Weibull statistics and analyzed with ANOVA. The other 15 specimens in each group were subjected to fatigue tests. The results were examined by Weibull statistics and subcritical crack propagation rates were calculated.@*Results@#The bending strengths of SG and CG were (1 291±133) and (1 140±124) MPa (F=10.117, P=0.004), and the Weibull modules of the two groups were 11.06 and 10.64 respectively. The crack growth rate of SCG of SG was lower than that of CG under the same cyclic loading.@*Conclusions@#Proper sandblasting on Y-TZP ceramic can increase its bending strength and resistance to SCG.

Influence of different surface treatment on the shear bond strength of zirconia-veneering ceramic systems / 实用口腔医学杂志

Objective:To assess the influence of different surface treatment on the adhesion of the zirconia-veneering ceramic systems.Methods:28 zirconia specimens were divided into 4 groups(n =7) and treated by non-treatment(group A,the control),sandblaste(group B),hot-etching(group C) and sandblaste + hot-etching(group D).2 specimens randomly selected from each group were examined under SEM and XRD for the observation of surface structure.The veneering porcelain was layered on the remaining specimens of the 4 groups (n =5),then the shear strength of the interface was tested by a universal testing machine.Data were statistically analyzed by SPSS 13.0 software.Results:Different degrees of micro pore structure was observed on the zircomia surface of the 4 groups by SEM observation.The XRD analysis showed that all specimens emerged monoclinic phase.The shear bond strength of group A,B,C and D was (15.96 ± 3.44) MPa,(20.58 ± 2.21) MPa,(26.28 4-2.86) MPa and (22.51 ± 1.94) MPa respectively.group A vs group B,C and D,P ＜ 0.05;group C vs group A,B and D,P ＜ 0.05.Conclusion:The surface treatment of sandblaste,hot-etching and sandblasted + hot-etching can improve the shear bond strength of the zirconia-veneering ceramic systems,and the hotetching method is the most effective.

Effects of different surface modifications on micro-structure and adhesion of zirconia ceramic: an in vitro study / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study evaluated the effect of different mechanical-chemical surface treatments on the characteristics, microstructure, and composition of zirconia ceramics and on the zirconia-dentin adhesion.</p><p><b>METHODS</b>The sintered commercial zirconia blocks (IPS e.max ZirCAD) were sectioned into 126 beams (6 mm×6 mm×5 mm) and randomly assigned to seven experimental groups (n=18). The zirconia block specimens were further treated as follows: (A) untreated, as control; (B) sandblasted with 50 μm Al2O3; (C) sandblasted with 50 μm Al2O3+30 μm silica powder; (D) sandblasted with 50 μm Al2O3+30% silica-sol coating; (E) sandblasted with 110 μm Al2O3; (F) sandblasted with 110 μm Al2O3+30 μm silica powder; and (G) sandblasted with 110 μm Al2O3+30% silica-sol coating. The surface roughness (Ra) of zirconia ceramics using X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) after seven surface treatments was analyzed. Seventy specimens of dentin surfaces were prepared. A dual-cure resin cement was applied into zirconia surfaces with its corresponding adhesive components to dentin. Shear bond strength (SBS) of each sample was measured using a universal testing machine. The data were analyzed by ANOVA using SPSS 17.0 software.</p><p><b>RESULTS</b>Ra of zirconia were significantly different compared with the control group (P<0.05). The crystalline transformation from tetragonal phase to monoclinic phase was observed after surface modification. Monoclinic volume content of the heat-treated group was highest than that in other groups. The content of element Si in the heat-treated group was higher than that in other treatment groups accompanied by a decrease in elements Zr, Y, and Hf after being treated by two silica-coating methods. Air abrasion significantly increased the micro-cracks in the ceramic surface and caused the grain boundaries to disappear. A serious shrinkage of the thin silica film can be observed after sintering procedure. This process induced cracks and the film to strip away slightly from the surfaces of Y-TZP substrate. The SBS values from large to small were F and G groups, C and D groups, B and E groups (P<0.05), and control group (P<0.05).</p><p><b>CONCLUSIONS</b>Alumina sandblasting, silica powder abrasion, and silica-sol coating affect the surface morphology, structure, and composition of the tooth. This effect can also achieve the improved micro-mechanical interlocking or chemical bonding and finally increase the bond strength between zirconia and tooth. Alumina sandblasting followed by silica coating is an effective technique to increase the bonding strength between the zirconia ceramic and dentin.
.</p>

The effects of sanding acid etch treatment of Ti-6Al-7Nb surface on rat osteoblasts / 天津医药

Objective To investigate the biocompatibility of pure titanium (Ti) and Ti-6Al-7Nb surface treated by sanding acid etch (SLA) on rat osteoblasts. Methods Experiments were divided into four groups, Ti mechanical grinding group (S1 group), Ti sand-blasting acid group (SLA1 group), Ti-6Al-7Nb mechanical grinding group (S2 group) and Ti-6Al-7Nb sand-blasting acid group (SLA2 group). The surface topography of samples was examined by microscope. The contact angle measurement instrument was used to analyse surface hydrophily of SLA1 and SLA2 groups. The surface sediment mor?phology and phase were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) in two groups after be?ing soaked into simulated body fluid (SBF) for 7 d,14 d and 21 d. Osteoblasts extracted from rats were seeded on titanium sheets, and the osteoblast cells on different titanium surfaces were observed by inverted microscope. MTT colorimetric meth?od was used to measure the proliferation of osteoblasts. Results Compared with S1 and S2 groups, there were more holes on sample surface of SLA1 and SLA2 groups. The sample surface was hydrophilic structure in SLA1 and SLA2 groups. The con?tact angle was smaller in SLA2 group than that of SLA1 group. The hydroxyapatite coating was firstly observed in SLA2 group at 14 d. The hydroxyapatite coating was found in samples of two groups after 21 d. The proliferative ability of osteo?blasts was stronger in SLA1 and SLA2 groups than that of S1 and S2 groups. And the proliferative ability of osteoblasts was stronger in sample surface of SLA2 group than that of SLA1 group (P<0.05). Conclusion Ti-6Al-7Nb by SLA has good biological compatibility, which is helpful to promote the combination of implant and bone tissue.

Effect of Using Nano and Micro Airborne Abrasive Particles on Bond Strength of Implant Abutment to Prosthesis

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.

A conexão das próteses nos pilares dos implantes dentários é um fator de preocupação e a obtenção de uma retenção satisfatória tem sido objeto de estudos recentes em próteses com retenção cementária. O jateamento é um método de obter uma superfície áspera para aumentar a retenção. O objetivo do presente estudo foi comparar os efeitos de jateamento com nano- e micropartículas abrasivas para tornar áspera a superfície dos pilares de implantes e a consequente aumentar a retenção dos copings cimentados. Trinta pilares Xive com seus análogos (4.5 D GH1) foram montados na posição vertical em blocos de acrílico auto-polimerizados. Copings metálicos de Ni-Cr com uma alça no topo foram feitos com adaptação marginal apropriada para cada pilar. Todas as amostras foram divididas em três grupos: o 1° grupo (MPS) foi jateado com micropartículas de Al2O3 com 50 µm de tamanho médio; o 2° grupo (NPS) foi jateado com nanopartículas de Al2O3 com 80 nm de tamanho médio; e o 3° grupo (C) foi considerado controle. As amostras foram cimentadas com cimento provisório (Temp Bond) e a resistência à tração dos copings cimentados foi avaliada em máquina universal de ensaios após processo de termociclagem. O teste t para amostras independentes foi usado para fins de análise estatística empregando-se o software SPSS v. 15, com nível de significância de 0,05. Os resultados demonstraram diferença significante entre todos os grupos (p<0,001) e o grupo MPS mostrou o maior valor médio de resistência de união (207,88±45,61 N) com diferenças significantes em relação aos outros grupos (p<0,001). Conforme previsto, o grupo controle obteve o menor valor de resistência (48,95±10,44 N). O jateamento com micro ou nano partículas mostrou-se um modo eficaz de aumentar significativamente a resistência de união, mas aparentemente as micropartículas são mais eficazes.

The effect of various sandblasting conditions on surface changes of dental zirconia and shear bond strength between zirconia core and indirect composite resin

PURPOSE: To measure the surface loss of dental restorative zirconia and the short-term bond strength between an indirect composite resin (ICR) and zirconia ceramic after various sandblasting processes. MATERIALS AND METHODS: Three hundred zirconia bars were randomly divided into 25 groups according to the type of sandblasting performed with pressures of 0.1, 0.2, 0.4 and 0.6 MPa, sandblasting times of 7, 14 and 21 seconds, and alumina powder sizes of 50 and 110 microm. The control group did not receive sandblasting. The volume loss and height loss on zirconia surface after sandblasting and the shear bond strength (SBS) between the sandblasted zirconia and ICR after 24-h immersion were measured for each group using multivariate analysis of variance (ANOVA) and Least Significance Difference (LSD) test (alpha=.05). After sandblasting, the failure modes of the ICR/zirconia surfaces were observed using scanning electron microscopy. RESULTS: The volume loss and height loss were increased with higher sandblasting pressure and longer sandblasting treatment, but they decreased with larger powder size. SBS was significantly increased by increasing the sandblasting time from 7 seconds to 14 seconds and from 14 seconds to 21 seconds, as well as increasing the size of alumina powder from 50 microm to 110 microm. SBS was significantly increased from 0.1 MPa to 0.2 MPa according to the size of alumina powder. However, the SBSs were not significantly different with the sandblasting pressure of 0.2, 0.4 and 0.6 MPa. The possibilities of the combination of both adhesive failure and cohesive failure within the ICR were higher with the increases in bonding strength. CONCLUSION: Based on the findings of this study, sandblasting with alumina particles at 0.2 MPa, 21 seconds and the powder size of 110 microm is recommended for dental applications to improve the bonding between zirconia core and ICR.

All Ceramic Cementation: A Key to Successful Restoration.

All-ceramic restorations are considered no more as future but established and scientifically documented reality of our daily activities as dental practitioner. To ensure successful and long-term durability of all ceramic restorations, one of the key requirements is adequate cementation. In spite of using all ceramic restorations so frequently in our routine practice, very few are aware of exact bonding mechanism for it. This review enlightens us about all the aspects of all ceramic cementation.

Effects of different surface treatments on shear bond strength of diatomite-based dental ceramic / 国际生物医学工程杂志

Objective To investigate the effects of different surface treatments on shear bond strength between diatomite-based dental ceramic and IPS e.max veneering ceramic.Methods Diatomite-based dental ceramic was randomly divided into acid-etched group,sandblasting group and untreated group,and then sintered with IPS e.max veneering ceramic,respectively.Shear bond strength were detected,and the interface microstructures and elemental distribution were observed by scanning electron microscope-energy dispersive spectrometer (SEM-EDS).Results Shear bond strength of acid-etched group was significantly higher than that of untreated group (P＜0.01).SEM observation results showed that the interface of acid-etched group bonded closely.There was no statistical difference of the shear bond strength between the sandblasting group and untreated group (P＞0.05).Conclusions Acid-etched treatment can significantly enhance the bond strength of diatomite-based dental ceramic and IPS e.max veneering ceramic.