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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

An attempt to mirror the painterly and stillness in autobiographical visual practice

Haikala, Eeva-Mari January 2016 (has links)
An Attempt to Mirror the Painterly and Stillness in Autobiographical Visual Practice is a practice-as-research project consisting of a portfolio of videos, photographs, and the documentation of live performances, and a written thesis. The written part is intended to work as a supportive body of material for the portfolio – or ‘brackets’, as it will be referred in the text – revealing the creative process behind those artworks, and the central thinkers, writers and artists that are relevant to this study, as well as offering contextualisation through an exploration of the lineage of other artists and discussions within which my practice-as-research project resides. The writing is built around the idea of ‘attempts’, in a written interpretation of a method I have applied to many of the artworks. Another key word of the study, the aforementioned brackets, is inspired by Virginia Woolf’s use of brackets in her novel To The Lighthouse. In this thesis I will explain the way in which these brackets have inspired me in the creation of many of the artworks. This will also offer an insight into how I relate to the text from within a visual artistic practice generally, and how using the brackets as a concept has also become a tool for identifying relationships between the art pieces presented in the portfolio and the written thesis itself. The text also reveals the multifaceted role of the painterly within this study project. The painterly will be discussed as a poetic-atmospheric visual frame for the artworks, and will also be explored in terms of how it emerges if the movement or the moving image is slowed down, which in turn brings this painterly quality of the artwork into close parallel with the still life painting genre. Finally, I will demonstrate, through the exploration of three artists from the past – Gwen John, Helene Schjerfbeck, and Virginia Woolf – the complexity of the writings of art history, biographies, and autobiographies.
32

Some quantum mechanical applications of the theory of Lie algebras

Wollenberg, L. S. January 1967 (has links)
No description available.
33

A comparison of negative-dimensional integration techniques

January 2021 (has links)
archives@tulane.edu / In this work, five algorithms of negative dimensional integration (NDIM) are compared in several examples of Feynman diagram calculations, and the resulting solutions are compared. The methods used are the Ricotta method without parametrization, the Ricotta method with Schwinger parametrization, the Suzuki method, the Anastasiou method, and the method of brackets. It is found that for one-loop diagrams, the method of brackets gives the same solution as the other methods, but without requiring analytic continuation of the gamma factors in the solution. For multi-loop diagrams, the method of brackets gives solutions in a simpler form than the other methods, and often gives fewer possible solutions as well. In addition to its use in the evaluation of Feynman diagrams, the method of brackets is also useful when extended to the evaluation of definite integrals over the positive real numbers. This extended method of brackets is applied to several examples of definite integrals, and the five NDIM methods are also used to evaluate these examples when possible. In particular, it is shown that the method of brackets is the only method of NDIM which may be extended to the evaluation of a large class of definite integrals over the positive real numbers. / 1 / Kristina E. VanDusen
34

Evaluation der Haftfestigkeit und des Debondingverhaltens einer neu entwickelten Bracketbasis im Basis- und Methodenvergleich / Evaluation of the bond strength and debonding behavior of a newly developed bracket base in a method and base comparison

Wetzel [verh. Theumer], Verena Marie January 2022 (has links) (PDF)
Ziel der Arbeit war die Bestimmung der Haftfestigkeit und des Debondingverhaltens verschiedener Bracket- und Adhäsivsysteme unter Berücksichtigung eines neu entwickelten Basisdesigns. Hierbei wurden zwei unterschiedliche Testmethoden sowie differierende Untergrundmaterialien verwendet. Zur Prüfung des Verbundes zwischen Bracket, Adhäsiv und Untergrund wurden gemäß der DIN 13990-2 die Brackets Bio Quick (Forestadent), Micro Sprint (Forestadent), Micro Sprint mit neu entwickelter Stotzenbasis (Forestadent), Equilibrium mini (Dentaurum) und In-Ovation mini (Dentsply) im Abscher- und Abzugversuch getestet. Sie wurden mit den Adhäsiven Transbond XT, Kurasper F und GC Ortho Connect auf bovine Zähne sowie auf PMMA-Ringe geklebt und anschließend hinsichtlich ihrer Haftfestigkeit untersucht. Vergleiche konnten außerdem zwischen den Testmethoden der Abscher- und Abzugtests wie auch der Untergrundmaterialien Zahn und Ring angestellt werden. Die Menge des Restadhäsivs auf der Bracketbasis wurde anschließend mikroskopisch bestimmt und anhand des Adhesive Remnant Index (ARI) dargestellt. Im Vergleich der Abscher- und Abzugprüfungen sowie der Untergründe Zahn und Ring konnten beim Abscheren der Brackets und der Anbringung auf Zähnen signifikant höhere Haftwerte erzielt werden. Unabhängig der Brackets ist auf den Zähnen kein signifikanter Unterschied zwischen den Adhäsiven zu erkennen, auf den Ringen hingegen erreicht GC Ortho Connect signifikant geringere Haftfestigkeiten. Die höchsten Haftfestigkeitswerte (in MPa) erreichten beim Abscheren vom Zahn und bei beiden Debondingmethoden vom Ring das Equilibrium mini in Kombination mit den Adhäsiven Kurasper auf dem Ring (Abscher 23,4 MPa/Abzug 8,1 MPa) und GC Ortho Connect auf dem Zahn (23,55 MPa). Beim Abzug vom Zahn erreichte das Micro Sprint mit Stotzenbasis in Kombination mit Transbond XT die höchste Haftfestigkeit (8,02 MPa). In der Untersuchung des ARI verblieb größtenteils mehr als 50% Restadhäsiv auf der Bracketbasis. / The objective of the work was to determine the bond strength and debonding behavior of different bracket and adhesive systems. Hereby, a newly developed basic design was taken into account. Two different test methods and different substrate materials were used. For testing the bond between bracket, adhesive, and substrate, the brackets Bio Quick (Forestadent), Micro Sprint (Forestadent), Micro Sprint with newly developed stotzen base (Forestadent), Equilibrium mini (Dentaurum), and In-Ovation mini (Dentsply) were tested by using shear and tensile tests in accordance with DIN 13990-2. The brackets were bonded to bovine teeth and PMMA rings using the adhesives Transbond XT, Kurasper F and GC Ortho Connect, and subsequently, their bond strength was analyzed. Comparisons could also be made between the test methods of the shear and tensile tests as well as the substrate materials tooth and ring. The residual adhesive on the bracket base was then determined microscopically and presented using the Adhesive Remnant Index (ARI). Comparing the shear and tensile tests and the tooth and ring bases, significantly higher adhesive values were obtained when the brackets were sheared off and attached to teeth. Regardless of the brackets, no significant difference between the adhesives can be seen on the teeth, but GC Ortho Connect achieved significantly lower bond strengths while using rings. In the conducted experiments, the highest bond strength (in MPa) were achieved when shearing from the tooth, and for both debonding methods from the ring by Equilibrium mini in combination with the adhesives Kurasper on the ring (shear bond strength 23.4 MPa/tensile bond strength 8.1 MPa) and GC Ortho Connect on the tooth (23.55 MPa). When pulled off the tooth, the Micro Sprint with stotzen base combined with Transbond XT achieved the highest bond strength (8.02 MPa). Mostly, more than 50% residual adhesive remained on the bracket base in the ARI examination.
35

The Effect of Wire Fixation Methods on the Measured Force Systems of a T-Loop Orthodontic Spring

Gregg, Joseph R. January 1997 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Ideal orthodontic springs are able to provide a controlled moment-to-force (M/F) ratio and a low load deflection rate. A great deal of research has gone into describing force systems generated by orthodontic springs. Most studies investigating the force system generated by T-loops have used rigid fixation for the spring ends. This is practical for laboratory studies, but it does not truly represent clinical situations in which orthodontic brackets are used to anchor spring ends. Results from laboratory studies have been applied to clinical situations without regard to what effect, if any, the method of end fixation may have. It is the goal of this study to determine the effects of spring fixation on generated force systems. The springs were held by rigid fixation and bracket ligation with either elastomeric or steel ligature ties. Comparison of these fixation methods was made by testing T-loops of different dimensions, with and without heat treatment at various activation distances. In theory, the wire is ligated rigidly against the bracket, so that the combination acts as a single unit by rigid fixation. Thus, there should be no difference between the generated force systems when spring ends are held by rigid fixation, or when they are held in place with orthodontic brackets and ligated by either elastomeric or steel ligature ties. However, the results indicate that are significant differences among the methods of fixation for each spring variation and heat treatment. The rigid fixation method consistently produced smaller moments and M/F ratios for all springs with every activation and heat treatment combination.
36

Evaluation of Tensile Bond Strength, Fluoride Release, Hardness, and Solubility of a Fluoride Containing Adhesive Resin

Brandt, Marybeth January 1994 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Direct bonding of orthodontic brackets often results in decalcification of tooth structure surrounding bracket sites. Glass ionomer cements, while typically leaching fluoride over time, often exhibit a significantly lower bond strength. Fluoride-containing resins generally release high concentrations of fluoride for a short time, then cease to release any significant amount. The purpose of this study was to evaluate the tensile bond strength, fluoride release, hardness, solubility, and sorption of a newly formulated fluoride containing resin. The experimental resins were prepared with 5% and 7.5% fluoride (F-) monomer, and were compared to a fluoride-free control adhesive (Rely-a-Bond Phase II™, Reliance Orthodontics Inc ., Itasca, Ill .). To evaluate tensile bond strength, orthodontic brackets were bonded to bovine teeth and debonded using an lnstron machine. Fluoride release was tested using resin disks stored in deionized water. The fluoride content of the water was determined with an ion-specific electrode. Hardness, solubility, and sorption were tested using disks made of each material. Comparison of experimental and control resins by ANOVA followed by General Linear Models multiple comparisons revealed the control to show a statistically significant difference (p<.0001) for tensile bond strength. Experimental Control 5%F- 7.5%F- Peak Stress (MPa) 4.48±0.65 3.83±0.76 5.31±0.97. Fluoride continued to be released from the experimental resins (5% and 7.5% F-) at 18 days. The control was significantly harder than either of the experimental resins at 1 hour, 24 hours, 1 week, and 1 month (p<.0001). The 5% F- resin exhibited slight solubility (0.10 percent), while the 7.5%F- resin and the control exhibited very little solubility (0.01 percent). Phase II™ exhibited significantly lower sorption at 21 days (0.60 percent, p<.001) than either the 5%F- resin (1.69 percent) or the 7.5%F- resin (1.63 percent). These results indicate that while the experimental resin had lower bond strength, lower hardness, and higher sorption than the control, measurable fluoride was released from the experimental resins for up to 18 days. Further testing is indicated to determine the clinical acceptability of this adhesive.
37

Effect of Adherent Contour on Orthodontic Tensile Bond Strength

Alvarez, Edwin January 2001 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Many factors may affect orthodontic bond strength study results. An important variant to consider is the bonding surface contour. Contour alters the proximity of adherent surfaces, the surface area available for adhesion, and the stress distribution. It was the purpose of this study to determine if bracket base or enamel contour affect in vitro bond strengths. Orthos Mini-Diamond (ORMCO Corp.) .0 018" slot central incisor brackets with flattened or unaltered curved bases were bonded (System 1 + self cure resin cement by ORMCO, Corp.) to unaltered and flattened bovine central incisors. Bond strengths were determined by debonding on a Bionix 858 (MTS System Corp.) testing machine. The results showed that unaltered bracket bases bonded on unaltered enamel surfaces (the closest approximation to a clinical situation) had the significantly (p< 0.0002) lowest tensile bond strength among the three combinations. The adhesive remnant index evaluation demonstrated that unaltered bracket base/ unaltered enamel surface (Group II) had significantly higher ARI (less adhesive remaining on enamel) than any of the other groups. A negative correlation between ARI scores and mean bond strength was found. There was not a significant difference between flattened bracket base / flattened enamel surface (Group I) and unaltered bracket base/ flattened enamel surface. The results suggest that the surface convexity and texture of enamel are important variables that can affect bond strength tests results. Standardization of testing protocols and control of the different variables that can affect bond strength are important factors in the testing of orthodontic brackets.
38

Alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon / Arch width and incisor torque changes produced by the Damon System

Valeria Matos Bezerra 19 December 2012 (has links)
PROPOSIÇÃO: O objetivo deste trabalho foi descrever as alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon, durante a fase de alinhamento e nivelamento. Outro objetivo foi verificar a correlação destas alterações com o padrão de crescimento dos indivíduos. MATERIAL E MÉTODOS: modelos de estudo, telerradiografias convencionais e telerradiografias reconstruídas a partir de tomografias computadorizadas cone-beam de 22 casos tratados com o bráquetes Damon 3MXTM foram avaliados durante a fase de alinhamento e nivelamento. Os modelos de estudo foram obtidos ao início do tratamento (T0), após a primeira troca de fio (T1) e na inserção do fio de aço 0,019 x 0,025 (T2). Foram verificados os comprimentos de arco e as dimensões transversais nas regiões de caninos, primeiros e segundos pré-molares e primeiros molares mensuradas a partir das pontas de cúspides e margens gengivais linguais dos dentes, a cada etapa. Nas telerradiografias foram verificadas as alterações das inclinações dos incisivos inferiores e superiores, bem como o padrão de crescimento dos indivíduos. RESULTADOS: os comprimentos dos arcos e todas as distâncias transversais apresentaram aumentos significantes, com exceção da distância intercervical dos caninos superiores; houve aumento significante das inclinações vestibulares dos incisivos superiores e inferiores; o padrão de crescimento dos pacientes apresentou correlação significante com os aumentos transversais na região de pré-molares inferiores. CONCLUSÕES: o alinhamento e nivelamento de casos tratados sem extrações com o uso do Sistema Damon resultou no aumento significante das dimensões dos arcos dentários e das inclinações dos incisivos para vestibular. / OBJECTIVE: This study aimed to evaluate the dental arch widths and incisor torque changes produced by the Damon System during leveling and alignment. Other objective was to verify the correlation between these changes and the growth pattern. MATHERIAL AND METHODS: study casts and lateral radiographs derived from cone-beam computed tomographies of 22 subjects treated with Damon 3MXTM brackets were evaluated. The study casts were obtained at the start of treatment (T0), the first archwire change (T1), and the placement of the final 0,019 x 0,025-in archwire (T2). Arch depth and widths (intercanine, interpremolar and intermolar) were assessed at each stage. The incisor torques changes and the growth pattern were measured on the cephalometric records at T0 and T2. RESULTS: There was significant increase of the arch depths and lateral expansion of the arches for all measures, except for the intercervical of maxillary canines. The maxillary and mandibular incisors were significantly tipped labially; the growth pattern showed significant correlation with the lateral increases in lower premolars region. CONCLUSIONS: nonextraction cases treated with Damon System show significant increases in arch dimensions and incisors proclination.
39

Alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon / Arch width and incisor torque changes produced by the Damon System

Bezerra, Valeria Matos 19 December 2012 (has links)
PROPOSIÇÃO: O objetivo deste trabalho foi descrever as alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon, durante a fase de alinhamento e nivelamento. Outro objetivo foi verificar a correlação destas alterações com o padrão de crescimento dos indivíduos. MATERIAL E MÉTODOS: modelos de estudo, telerradiografias convencionais e telerradiografias reconstruídas a partir de tomografias computadorizadas cone-beam de 22 casos tratados com o bráquetes Damon 3MXTM foram avaliados durante a fase de alinhamento e nivelamento. Os modelos de estudo foram obtidos ao início do tratamento (T0), após a primeira troca de fio (T1) e na inserção do fio de aço 0,019 x 0,025 (T2). Foram verificados os comprimentos de arco e as dimensões transversais nas regiões de caninos, primeiros e segundos pré-molares e primeiros molares mensuradas a partir das pontas de cúspides e margens gengivais linguais dos dentes, a cada etapa. Nas telerradiografias foram verificadas as alterações das inclinações dos incisivos inferiores e superiores, bem como o padrão de crescimento dos indivíduos. RESULTADOS: os comprimentos dos arcos e todas as distâncias transversais apresentaram aumentos significantes, com exceção da distância intercervical dos caninos superiores; houve aumento significante das inclinações vestibulares dos incisivos superiores e inferiores; o padrão de crescimento dos pacientes apresentou correlação significante com os aumentos transversais na região de pré-molares inferiores. CONCLUSÕES: o alinhamento e nivelamento de casos tratados sem extrações com o uso do Sistema Damon resultou no aumento significante das dimensões dos arcos dentários e das inclinações dos incisivos para vestibular. / OBJECTIVE: This study aimed to evaluate the dental arch widths and incisor torque changes produced by the Damon System during leveling and alignment. Other objective was to verify the correlation between these changes and the growth pattern. MATHERIAL AND METHODS: study casts and lateral radiographs derived from cone-beam computed tomographies of 22 subjects treated with Damon 3MXTM brackets were evaluated. The study casts were obtained at the start of treatment (T0), the first archwire change (T1), and the placement of the final 0,019 x 0,025-in archwire (T2). Arch depth and widths (intercanine, interpremolar and intermolar) were assessed at each stage. The incisor torques changes and the growth pattern were measured on the cephalometric records at T0 and T2. RESULTS: There was significant increase of the arch depths and lateral expansion of the arches for all measures, except for the intercervical of maxillary canines. The maxillary and mandibular incisors were significantly tipped labially; the growth pattern showed significant correlation with the lateral increases in lower premolars region. CONCLUSIONS: nonextraction cases treated with Damon System show significant increases in arch dimensions and incisors proclination.
40

Bond strength of metal orthodontic brackets to all ceramic crowns

Ismail, Moosa January 2016 (has links)
Magister Scientiae Dentium - MSc(Dent) / Aim: The aim of this study was to evaluate, in-vitro, the shear bond strength (SBS) and the resultant failure pattern after debonding of metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement and RelyXTM Unicem 2 self-adhesive resin cement to pre-treated (35% ortho-phosphoric acid and silane coupling agent application) IPS eMax and porcelain veneered zirconia crowns. Material and methodology: A Typhodont maxillary lateral incisor was used and prepared in a conventional manner to receive a full ceramic crown. A CAD (computer aided design)/ CAM (computer aided manufacturing) machine was used to scan the prepared tooth and manufacture 40 IPS eMax crowns and 40 porcelain veneered zirconia crowns. Half the number of IPS eMax crown specimens (ie. 20) and half the number of porcelain veneered zirconia crown specimens (ie. 20) were thermocycled (ie. to mimic thermal changes which occur in the mouth), from 5 to 55o for 500 cycles as recommended by the International Organization for Standardization (ISO 6872, 2008). The remaining 20 IPS eMax crown specimens and 20 porcelain veneered zirconia crown specimens remained new and unexposed to thermal changes. The facial surfaces of all the thermocycled and non-thermocycled crown specimens were then etched. Etching of all the ceramic bonding surfaces was performed by the application of 35 per cent ortho-phosphoric acid liquid for 2 minutes, followed by a thin layer of a ceramic primer. A lateral incisor metal bracket with a bracket base area of 9mm2 (as confirmed by the manufacturer) was bonded to each of the etched and silane treated ceramic crown specimens and separated in the following manner: Group 1: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 2: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin was used to bond the bracket to the ceramic crown specimens, Group 3: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 4: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin cement was used to bond the bracket to the ceramic crown specimens. After bonding all samples were stored in distilled water for 24 hours before being submitted to the shear bond strength test. Debonding forces in Newtons (N) was determined by using a shear testing machine and converted into Mega Pascals (MPa). Results: The results after debonding were compared. The mean shear bond strength for RelyXTM Unicem 2 self-adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 3) ranged from a low of 5.1 MPa (45.5 Newtons) when brackets were bonded to the IPS eMax crowns to a high of 5.8 MPa (51.9 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns. The mean shear bond strength for Transbond XT adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 4) ranged from a low of 6.4 MPa (57.3 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns to a high of 8.1 MPa (72.7 Newtons) when brackets were bonded to the IPS eMax crowns. The side by side Box-and-Whisker plots of the shear bond strengths show wide and overlapping dispersions of the crown/adhesive resin combinations which consequently lessen the probability of significant differences between the crown/adhesive resin combinations in all 4 groups. According to the Kruskal-Wallis test (p < 0.05), and the Bonferroni Test the non-thermocycled crown/adhesive resin combinations do not differ significantly. Study of the mean ARI (Adhesive Remnant Index) values for the non-thermocycled crown/adhesive combinations shows that brackets bonded with Rely-XTM Unicem 2 to non-thermocycled porcelain veneered zirconia crowns failed entirely at the ceramic/adhesive interface and for all the other non-thermocycled ceramic/adhesive combinations most of the failures of the bond (70%) occurred at the bracket/adhesive interface, ie. cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted. The results of the thermocycled groups (Group 1 and Group 2) show the TransbondTM XT/non-thermocycled IPS eMax crown combination yielded the highest overall mean shear bond strength of 8.1 MPa (72.7 Newtons) but dropped to a mean shear bond strength of 5.1 MPa (46.1 Newtons) (36.4% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The TransbondTM XT/non-thermocycled porcelain veneerd zirconia crown combination yielded the second highest overall mean shear bond strength of 6.4 MPa (57.3 Newtons) and dropped to a mean shear bond strength of 5.1 MPa (45.8 Newtons) (19.3% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The RelyXTM Unicem 2/non-thermocycled porcelain veneered zirconia crown combination yielded the third highest overall mean shear bond strength of 5.8 MPa (51.9 Newtons) but dropped significantly to a mean shear bond strength of 3.2 MPa (29.1 Newtons) (a significant 43.8% drop in shear bond strength) when the crowns were thermocycled prior to bonding. Lastly, the RelyXTM Unicem 2/non-thermocycled IPS eMax crown combination yielded the fourth highest mean shear bond strength of 5.1MPa (45.5 Newtons) but dropped to a mean shear bond strength of 4.9 MPa (44.5 Newtons) (a drop in shear bond strength of only 3%) when the crowns were thermocyled prior to bonding. Relaxing the significance level (p-value) somewhat demonstrates the negative influence of thermocycling on the shear bond strength of the crown/adhesive combinations. The non-thermocycled all ceramic crown/adhesive combinations showed mean ARI values of between 1.3 and 2.1 indicating cohesive fractures within the composite resin and efficient bonding of the adhesive material to the porcelain surface. However, all the thermocycled all ceramic crown/adhesive treatment combinations showed mean ARI values of between 0 and 0.8 indicating a bond failure between adhesive and porcelain and highlighting the negative influence of thermocycling on bond strength of both adhesive resin cements. Conclusion: Within the limitations of this study, it can be concluded that: 1.There was no significant difference in the shear bond strengths of metal orthodontic brackets bonded with RelyXTM Unicem 2 self-adhesive resin cement and metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement to IPS eMax and porcelain-veneered zirconia crowns which were conditioned with 35 % phosphoric acid and a silane coupling agent. 2. Conditioning the porcelain surface with 35% phosphoric acid and a silane coupling agent (which is safer to use than Hydrofluoric acid) is sufficient for bonding metal orthodontic brackets to all ceramic crowns, and should make it simpler for clinicians to remove the remaining adhesive from the porcelain surface after debonding. 3. The negative influence of thermocycling prior to bonding can be seen on shear bond strength values. 4. Most of the failures of the bond occurred at the ceramic/adhesive interface and cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted.

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