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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.
11

Developing strategies for the control of Ichthyophthirius multifiliis Fouquet, 1876 (Ciliophora)

Picon Camacho, Sara M. January 2010 (has links)
The intensification of freshwater aquaculture worldwide has facilitated the propagation of the parasitic ciliate protozoan Ichthyophthirius multifiliis Fouquet, 1876 commonly known as “fish white spot” or “Ich”. Ichthyophthirius multifiliis infections lead to high mortalities, generating significant economic losses in most cultured freshwater fish species worldwide. Until recently, malachite green was the chemical treatment traditionally used to control I. multifiliis infections. Its reclassification as carcinogenic to humans and its subsequent ban for use in food fish has left the industry without any suitable treatments. Currently, in-bath formaldehyde and sodium chloride treatments are the most common option used in farm systems to control I. multifliis infections. Given their low efficacy, however, they are not considered as sustainable long–term options. There is, therefore, an urgent necessity to find efficacious alternatives for controlling I. multifliis infections. The general aim of this research project was to improve the management of I. multifiliis infections in order to develop more comprehensive, environmentally friendly and sustainable therapeutic strategies for use in freshwater food fish aquaculture. The present PhD-thesis present first a literature review chapter providing an overview and critical assessment of chemotherapeutants and physical interventions tested within the last 30 years against I. multifiliis infections. The experimental worked consisted of a number of in vitro and in vivo trials were conducted using experimental scale flow-through, static tank systems and commercial scale raceways within a rainbow trout hatchery, in addition to molecular work on different isolates of the parasite. The results of this research are organised into three experimental chapters which describe the testing of chemical and non-chemical treatments against I. multifiliis infections and work undertaken to determine the most suitable molecular markers to identify I. multifiliis isolates. In the first experimental chapters, the possibility of efficiently controlling I. multifliis infections through the administration of novel environmentally-friendly chemical treatments (e.g. bronopol and peracetic acid-based products) was investigated. The results clearly showed that bronopol and peractic acid-based products have a strong biocidal/cytotoxic effect against all free-living stages of I. multifiliis (e.g. tomonts, cysts and theronts). The administration of high concentrations of bronopol (e.g. 20, 50 and 100 mg L-1) over short periods of exposure (e.g. 30 min) significantly reduced the survival of tomonts, cysts and theronts and delayed the development of I. multifiliis tomonts and cysts. Prolonged low concentrations of bronopol (e.g. 1 mg L-1) greatly reduced the survival of infective theronts, although such treatment did not affect the ability of surviving theronts to subsequently infect a host. When tested in vivo, the continuous prolonged exposure (e.g. 27 days) of low concentrations of bronopol (e.g. 2 and 5 mg L-1) had an impact on the population dynamics of I. multifiliis, this being demonstrated by a significant reduction in the number of trophonts developing within the fish. Low concentrations of bronopol (e.g. 2 mg L-1) administrated as a preventive treatment prior to infection also proved to be very successful at reducing the colonisation success of I. multifiliis. Peracetic acid administrated at low concentrations (e.g. 8, 12 and 15 mg L-1) over a short window of exposure (e.g. 1 h) displayed a strong biocidal effect against all the free-living stages of I. multifiliis (e.g. tomonts, cysts and theronts). The bronopol and peracetic acid-based products tested here both appear to be capable of disrupting the development of the cyst stage of I. multifiliis which is seldom reported for chemotherapeutants currently used against this parasite. These results suggest that bronopol and peracetic acid-based products have a place in the arsenal of treatment options for controlling I. multifiliis infections in commercial aquaculture systems. The use of a mechanical device or a biological control agent to remove the cyst stage of I. multifiliis and the impact of such control on the population dynamics and the levels of infection of fish were also investigated. The results revealed that tomonts preferentially settle and encyst on the base of culture systems and on biofilm–covered substrates. The survival of the tomont stage is greatly affected by the composition of the substrate upon which it settles and is significantly lower on polypropylene-based plastic. The lining of raceways in a commercial rainbow trout hatchery with a low-adhesion polymer created a smooth surface facilitating the dislodgement and elimination of the cyst stage of I. multifilis by natural flushing or brushing. The physical removal of the cyst stage alone, through the use of a mechanical device or substrate detrivorous/algae feeder as a biological control agent, significantly reduced the propagation of I. multifiliis to a low level of infection without the need to deploy an additional chemical treatment. These studies demonstrate that the cyst is a key stage in the dynamics of I. multifiliis infection and its removal from the fish culture systems could constitute an effective and simple mean of managing I. multifiliis infections. The third experimental chapter explores the utilisation of molecular marker to characterise different isolates of I. multifiliis. The results highlight the unsuitability of the rDNA region (ITS-1 and ITS-2) and the strong potential of the mtDNA (COI) as molecular markers to discriminate isolates of I. multifiliis from distant geographical locations. It is suggested that genetic “barcoding” using mtDNA is the most effective method to identify I. multifiliis isolates. Importantly, genetic “barcoding” could allow associating I. multifiliis strains or geographical isolates with particular properties as regards their ecophysiology, pathogenicity and sensitivity to treatment, in order to improve the management of I. multifiliis infections according to the specific genetic isolate encountered. This research project demonstrates the efficacy of a range of new approaches against the propagation of I. multifiliis. Together, our findings contribute towards the development of a more effective and integrated system for managing I. multifliis infections in farm systems. The utilisation of physical methods and of environmentally friendly chemotherapeutants holds great potential for the control of I. multifiliis infections in organic fish production and in a broader context to any freshwater food fish farms affected by I. multifiliis.
12

Desenvolvimento e caracterização de adesivo ortodôntico contendo triazina e vidro bioativo nióbio-fosfato

Altmann, Aline Segatto Pires January 2015 (has links)
Pacientes ortodônticos apresentam grande prevalência de lesões de mancha branca devido ao maior acúmulo de biofilme em torno dos brackets. O objetivo deste estudo foi desenvolver um adesivo ortodôntico que apresentasse atividade antibacteriana e que estimulasse a deposição mineral para evitar o aparecimento e/ou a evolução destas lesões. Adesivos experimentais foram formulados contendo 75% de BisGMA e 25% de TEGDMA por peso; sistema fotoiniciador a base de canforoquinona e 5% de sílica coloidal. Os compostos 1,3,5-triacriloilhexahidro-1,3,5-triazina (TAT) e vidro fosfato invertido contendo pentóxido de nióbio (PIG-Nb) foram adicionados ao adesivo base, como agente antibacteriano e remineralizante, respectivamente. Foram analisados grupos contendo somente TAT nas concentrações de 10, 15 e 20% por peso; grupos contendo somente PIG-Nb nas concentrações de 1, 2,5 e 5% por peso e um grupo contendo 20% TAT e 5% PIG-Nb, por peso. Utilizou-se um grupo sem a adição de TAT e PIG-Nb como Grupo Controle, dentre os experimentais. O adesivo ortodôntico comercial Transbond XT foi utilizado para comparação. Avaliou-se a atividade antibacteriana, capacidade de deposição mineral, variação de pH, grau de conversão, amolecimento em solvente e resistência de união dos adesivos ortodônticos. Os adesivos desenvolvidos apresentaram atividade antibacteriana e capacidade de estimular deposição mineral sem prejudicar as propriedades dos adesivos. Os resultados obtidos a partir dos ensaios realizados neste trabalho permitem concluir que se trata de material com propriedades favoráveis e potencialidade de, após ajustes necessários, tornar-se viável para uso na prática odontológica. / White spot lesions are a concern for orthodontic patients due to biofilm accumulation around brackets. The aim of this study was to develop an antibacterial and remineralizing orthodontic adhesive to overcome these lesions. Experimental orthodontic adhesives were formulated containing 75wt% BisGMA and 25wt% TEGDMA; camphorquinone-based photoinitiator system and 5wt%fummed silica. The compounds 1,3,5-tryacryloylhexahydro-1,3,5-triazine (TAT) and phosphate invert glass containing niobium pentoxide (PIG-Nb) were added to the adhesive as antibacterial and remineralizing agents, respectively. Experimental groups obtained containing only TAT at 10, 15 and 20wt% concentration; groups containing only PIG-Nb at 1, 2.5 and 5wt%, and one group containing 20wt% TAT and 5wt% PIG-Nb. A groups without TAT and PIG-Nb was used as Control and Transbond XT was used as a commercial control. Antibacterial activity, mineral deposition, changes in pH, degree of conversion, softening in solvent and shear bond strength of orthodontic adhesives was assessed. The experimental adhesives presented antibacterial activity and were capable to induce mineral deposition with no negative effect on adhesive's properties. The results of this study allow the conclusion that this material has favorable properties and potential, after necessary adjustments become viable for use in dental practice.
13

Desenvolvimento e caracterização de adesivo ortodôntico contendo triazina e vidro bioativo nióbio-fosfato

Altmann, Aline Segatto Pires January 2015 (has links)
Pacientes ortodônticos apresentam grande prevalência de lesões de mancha branca devido ao maior acúmulo de biofilme em torno dos brackets. O objetivo deste estudo foi desenvolver um adesivo ortodôntico que apresentasse atividade antibacteriana e que estimulasse a deposição mineral para evitar o aparecimento e/ou a evolução destas lesões. Adesivos experimentais foram formulados contendo 75% de BisGMA e 25% de TEGDMA por peso; sistema fotoiniciador a base de canforoquinona e 5% de sílica coloidal. Os compostos 1,3,5-triacriloilhexahidro-1,3,5-triazina (TAT) e vidro fosfato invertido contendo pentóxido de nióbio (PIG-Nb) foram adicionados ao adesivo base, como agente antibacteriano e remineralizante, respectivamente. Foram analisados grupos contendo somente TAT nas concentrações de 10, 15 e 20% por peso; grupos contendo somente PIG-Nb nas concentrações de 1, 2,5 e 5% por peso e um grupo contendo 20% TAT e 5% PIG-Nb, por peso. Utilizou-se um grupo sem a adição de TAT e PIG-Nb como Grupo Controle, dentre os experimentais. O adesivo ortodôntico comercial Transbond XT foi utilizado para comparação. Avaliou-se a atividade antibacteriana, capacidade de deposição mineral, variação de pH, grau de conversão, amolecimento em solvente e resistência de união dos adesivos ortodônticos. Os adesivos desenvolvidos apresentaram atividade antibacteriana e capacidade de estimular deposição mineral sem prejudicar as propriedades dos adesivos. Os resultados obtidos a partir dos ensaios realizados neste trabalho permitem concluir que se trata de material com propriedades favoráveis e potencialidade de, após ajustes necessários, tornar-se viável para uso na prática odontológica. / White spot lesions are a concern for orthodontic patients due to biofilm accumulation around brackets. The aim of this study was to develop an antibacterial and remineralizing orthodontic adhesive to overcome these lesions. Experimental orthodontic adhesives were formulated containing 75wt% BisGMA and 25wt% TEGDMA; camphorquinone-based photoinitiator system and 5wt%fummed silica. The compounds 1,3,5-tryacryloylhexahydro-1,3,5-triazine (TAT) and phosphate invert glass containing niobium pentoxide (PIG-Nb) were added to the adhesive as antibacterial and remineralizing agents, respectively. Experimental groups obtained containing only TAT at 10, 15 and 20wt% concentration; groups containing only PIG-Nb at 1, 2.5 and 5wt%, and one group containing 20wt% TAT and 5wt% PIG-Nb. A groups without TAT and PIG-Nb was used as Control and Transbond XT was used as a commercial control. Antibacterial activity, mineral deposition, changes in pH, degree of conversion, softening in solvent and shear bond strength of orthodontic adhesives was assessed. The experimental adhesives presented antibacterial activity and were capable to induce mineral deposition with no negative effect on adhesive's properties. The results of this study allow the conclusion that this material has favorable properties and potential, after necessary adjustments become viable for use in dental practice.
14

Desenvolvimento e caracterização de adesivo ortodôntico contendo triazina e vidro bioativo nióbio-fosfato

Altmann, Aline Segatto Pires January 2015 (has links)
Pacientes ortodônticos apresentam grande prevalência de lesões de mancha branca devido ao maior acúmulo de biofilme em torno dos brackets. O objetivo deste estudo foi desenvolver um adesivo ortodôntico que apresentasse atividade antibacteriana e que estimulasse a deposição mineral para evitar o aparecimento e/ou a evolução destas lesões. Adesivos experimentais foram formulados contendo 75% de BisGMA e 25% de TEGDMA por peso; sistema fotoiniciador a base de canforoquinona e 5% de sílica coloidal. Os compostos 1,3,5-triacriloilhexahidro-1,3,5-triazina (TAT) e vidro fosfato invertido contendo pentóxido de nióbio (PIG-Nb) foram adicionados ao adesivo base, como agente antibacteriano e remineralizante, respectivamente. Foram analisados grupos contendo somente TAT nas concentrações de 10, 15 e 20% por peso; grupos contendo somente PIG-Nb nas concentrações de 1, 2,5 e 5% por peso e um grupo contendo 20% TAT e 5% PIG-Nb, por peso. Utilizou-se um grupo sem a adição de TAT e PIG-Nb como Grupo Controle, dentre os experimentais. O adesivo ortodôntico comercial Transbond XT foi utilizado para comparação. Avaliou-se a atividade antibacteriana, capacidade de deposição mineral, variação de pH, grau de conversão, amolecimento em solvente e resistência de união dos adesivos ortodônticos. Os adesivos desenvolvidos apresentaram atividade antibacteriana e capacidade de estimular deposição mineral sem prejudicar as propriedades dos adesivos. Os resultados obtidos a partir dos ensaios realizados neste trabalho permitem concluir que se trata de material com propriedades favoráveis e potencialidade de, após ajustes necessários, tornar-se viável para uso na prática odontológica. / White spot lesions are a concern for orthodontic patients due to biofilm accumulation around brackets. The aim of this study was to develop an antibacterial and remineralizing orthodontic adhesive to overcome these lesions. Experimental orthodontic adhesives were formulated containing 75wt% BisGMA and 25wt% TEGDMA; camphorquinone-based photoinitiator system and 5wt%fummed silica. The compounds 1,3,5-tryacryloylhexahydro-1,3,5-triazine (TAT) and phosphate invert glass containing niobium pentoxide (PIG-Nb) were added to the adhesive as antibacterial and remineralizing agents, respectively. Experimental groups obtained containing only TAT at 10, 15 and 20wt% concentration; groups containing only PIG-Nb at 1, 2.5 and 5wt%, and one group containing 20wt% TAT and 5wt% PIG-Nb. A groups without TAT and PIG-Nb was used as Control and Transbond XT was used as a commercial control. Antibacterial activity, mineral deposition, changes in pH, degree of conversion, softening in solvent and shear bond strength of orthodontic adhesives was assessed. The experimental adhesives presented antibacterial activity and were capable to induce mineral deposition with no negative effect on adhesive's properties. The results of this study allow the conclusion that this material has favorable properties and potential, after necessary adjustments become viable for use in dental practice.
15

Characterizations of the Major Coral Diseases of the Philippines: Ulcerative White Spot Disease and Novel Growth Anomalies of Porites

Kaczmarsky, Longin T 09 November 2009 (has links)
Coral reefs are in decline worldwide and coral disease is a significant contributing factor. However, etiologies of coral diseases are still not well understood. In contrast with the Caribbean, extremely little is known about coral diseases in the Philippines. In 2005, off Southeast Negros Island, Philippines, I investigated relationships between environmental parameters and prevalence of the two most common coral diseases, ulcerative white spot (UWS) and massive Porites growth anomalies (MPGAs). Samples were collected along a disease prevalence gradient 40.5 km long. Principal component analyses showed prevalence of MPGAs was positively correlated with water column nitrogen, organic carbon of surface sediments, and colony density. UWS was positively correlated with water column phosphorus. This is the first quantitative evidence linking anthropogenically-impacted water and sediment to a higher prevalence of these diseases. Histological and cytological alterations were investigated by comparing tissues from two distinct types of MPGA lesions (types 1 and 2) and healthy coral using light and electron microscopy. Skeletal abnormalities and sloughing, swelling, thinning, and loss of tissues in MPGAs resembled tissues exposed to bacterial or fungal toxins. Both lesion types had decreases in symbiotic zooxanthellae, which supply nutrients to corals. Notable alterations included migrations of chromophore cells (amoebocytes) (1) nocturnally to outer epithelia to perform wound-healing, including plugging gaps and secreting melanin in degraded tissues, and (2) diurnally to the interior of the tissue possibly to prevent shading zooxanthellae in order to maximize photosynthate production. Depletion of melanin (active in wound healing) in type 2 lesions suggested type 2 tissues were overtaxed and less stable. MPGAs contained an abundance of endolithic fungi and virus-like particles, which may result from higher nutrient levels and play roles in disease development. Swollen cells and mucus frequently blocked gastrovascular canals (GVCs) in MPGAs. Type 1 lesions appeared to compensate for impeded flow of wastes and nutrients through these canals with proliferation of new GVCs, which were responsible for the observed thickened tissues. In contrast, type 2 tissues were thin and more degraded. Dysplasia and putative neoplasia were also observed in MPGAs which may result from the tissue regeneration capacity being overwhelmed.
16

Effectiveness of Mi PasteTM, Mi Paste PlusTM, and Topex RenewTM in remineralization and visible reduction of white spot lesions after orthodontic treatment - a clinical study

Shell, Eric Radcliff 01 May 2012 (has links)
Introduction: Orthodontic treatment is meant to provide patients with stable occlusion and an esthetic smile, and often improves a patient's self-esteem. Unfortunately, and too often, an ideal orthodontic finish in terms of alignment and occlusion is tarnished by the appearance of white spot lesions on the facial surface of teeth after removing the fixed appliances. These white spots detract from the esthetics of a patient's smile. Purpose: The objective of this study was to evaluate the effectiveness of MI PasteTM (GC America, Alsip, Illinois), MI Paste PlusTM (GC America, Alsip, Illinois), and Topex RenewTM (Sultan Healthcare, Hackensack, NJ) in increasing remineralization and improving the esthetic appearance of white spot lesions in patients after treatment with fixed orthodontic appliances. In addition, at-home only versus in-office and at-home treatment protocols were evaluated. Methods and Materials: Thirty patients were enrolled in four treatment groups and a control group, with six patients in each group. The study lasted three months and results were analyzed with normal and QLF photographs. Results, Discussion, and Conclusion: Upon completion of this clinical study, the following conclusions can be drawn. First, the visible area and the fluorescence decrease of white spot lesions will both significantly lessen after orthodontic treatment regardless of products used, or even with a non-prescription fluoride toothpaste control. Second, there is some evidence that an at-home treatment protocol using Topex Renew, or a combination in-office and at-home treatment protocol with MI Paste Plus, may be more beneficial in reducing the appearance of white spot lesions after orthodontic treatment than other treatment protocols.
17

Comparison between Opal®Seal and L.E.D. Pro Seal® in resistance to wear and effectiveness against enamel demineralization : an in vitro study

Woolfson, Hayley 01 January 2013 (has links)
A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objective: This study was conducted to determine the resistance to wear and effectiveness of Opal®Seal (Opal Orthodontics by Ultradent, South Jordan, UT, USA) against enamel demineralization in comparison to L.E.D. Pro Seal® (Reliance Orthodontic Products, Itasca, IL, USA). Background: Development of white spot lesions (WSL) is a primary concern during fixed orthodontic treatment. With poor oral hygiene during orthodontic therapy, it is almost inevitable that enamel demineralization will occur and WSLs will be seen clinically. Numerous materials have demonstrated successful prevention of WSLs, including topical varnishes and sealants, gels, pastes and bonding agents. The newly developed sealant Opal Seal is claimed by the manufacturer to prevent demineralization and subsequent WSLs from forming during orthodontic treatment. To evaluate the effectiveness of Opal Seal, we tested and compared it to Pro Seal, which has proven to be successful at WSL prevention and is, like Opal Seal, a fluoride-releasing, light-cured, low viscosity filled resin sealant. Methods: A total of 48 non-carious extracted human premolar teeth were divided into 3 groups representing one of the following topical treatments: no treatment (C), Opal Seal (OS) or L.E.D. Pro Seal (PS). Each group was subdivided into either T1 or T2 time interval groups (C1, C2, OS1, OS2, PS1 and PS2) and teeth were subjected to 10,000 or 20,000 simulated brush strokes, respectively, followed by exposure to an acidic solution for 96 hours. Teeth were examined macroscopically for product wear and assessment of WSL development and then sectioned for quantitative examination with polarized light microscopy. Results: Visual assessment revealed wear of L.E.D. Pro Seal in 62.5% of the PS2 teeth following exposure to toothbrush abrasion and acidic challenge. No L.E.D. Pro Seal or Opal Seal wear was found in any PS1 or OS teeth, respectively. WSLs involving 50-100% of the exposed enamel surface developed in all control teeth and 37.5% of PS teeth had WSLs involving less than 50% of their enamel surface. These WSLs were visible as small, white, isolated points. No visible WSLs were found in any teeth in the OS group. A Fisher's Exact test was used to evaluate any differences in demineralization within groups over time. The results indicate a significant difference in the number of lesions found at T1 compared to T2 in the PS group (p = 0.003). A non-parametric Kruskal-Wallis test using a Wilcoxon test for all multiple comparisons was conducted to evaluate any differences among the treatment groups for change in depth of demineralization (µm) at two different time points. PS and OS groups were found to have significant differences in average lesion depth compared to the control groups at T1 and T2 (pConclusions: Our results showed that both Opal Seal and L.E.D. Pro Seal reduce enamel demineralization when teeth are subjected to simulated toothbrush abrasion and an acidic environment over time. Opal Seal provided superior protection of the enamel surface and demonstrated complete wear resistance and prevention of demineralized lesion development in our experimental groups.
18

Evaluation of the effect of enamel deproteinization on shear bond strength of orthodontic adhesives and resulting white spot lesion formation

Chioffe, Kelly 01 January 2014 (has links)
A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objective: The objectives of this study were 1) to evaluate the effect of enamel deproteinization on the shear bond strength(SBS) of orthodontic brackets bonded with a resin modified glass-ionomer (RMGI) adhesive and a composite resin, 2) to determine the mode of bond failure according to the adhesive remnant index (ARI) and 3) to evaluate the effect of these adhesives in the prevention of white spot lesions (WSLs). Background: WSLs are a concern for orthodontic patients. RMGI orthodontic adhesives are capable of absorbing fluoride from the oral environment and releasing it continuously over time, however, they are not frequently used as they exhibit low SBS. Techniques such as non-invasive enamel deproteinization with 5.25% sodium hypochlorite prior to acid etching rid the surface of organic components and have the potential to enhance the etching pattern. Methods: Eighty-eight extracted bovine incisors were randomly divided into two groups. 48 incisors in group (A) underwent SBS testing, through debonding of brackets with the Universal Testing Machine and subsequent measurement of the ARI. 40 incisors in group (B) underwent demineralization testing by measuring the depth of WSLs formed after exposure to an acidic challenge for 96 hours. In groups A and B, the teeth were divided to have brackets bonded with GC Fuji ORTHO™ LC adhesive or Transbond™ XT adhesive and a self-etching primer. Each adhesive group had an experimental group receiving the intervention of enamel deproteinization prior to etching and bonding and a control group. Results: The highest mean SBS was observed in the Transbond™ XT control group (12.48 ± 6.23 MPa) and the lowest mean SBS was observed in the Fuji ORTHO™ experimental group (5.49 ± 2.97 MPa). ANOVA and Post-Hoc Tukey tests revealed statistically significant differences (p<0.05) in the SBS of both Fuji ORTHO™ groups compared to the Transbond™ XT control group. A significantly greater percentage of Transbond™ XT control teeth had an ARI score of 0 and a greater percentage of Fuji ORTHO™ experimental teeth had an ARI score of 3. The Transbond™ XT experimental group had the largest average demineralization lesions (62.97 ± 10.95 micrometers). The smallest lesion depths were found in the Fuji ORTHO™ groups, with an average of 7.74 micrometers in the experimental group and 6.57 micrometers in the control group. ANOVA and Post-Hoc Tukey tests revealed significant differences (p<0.001) in the depth of white spot lesions when comparing both composite resin groups to each other, and when each glass ionomer group was compared to each composite resin group. Conclusions: Enamel deproteinization did not increase the SBS of orthodontic brackets bonded with either Fuji ORTHO™ adhesive or Transbond™ XT adhesive. However, according to the ARI, more bond failures occurred at the bracket-adhesive interface in the Fuji ORTHO™ experimental group. Also, both Fuji ORTHO™ adhesive groups showed greater protection against enamel demineralization, when compared to the Transbond™ XT adhesive groups.
19

Prevalence of white spot lesions in maxilla and mandible in orthodontic patients with fixed appliance treated with a high fluoride varnish or a placebo varnish : -A randomized controlled trial on adolescents

Wallman, Lisa, Sörebö, Christoffer January 2022 (has links)
Aim: The aim of this study was to investigate if there is a beneficial effect on the prevalence of white spot lesions (WSL) in the mandibular and maxillary teeth when the teeth in the maxilla are treated with fluoride varnish compared to a placebo group. The null hypothesis was that there is no difference between the test and placebo group in development of WSL. Material and Method: 182 patients from three clinics in Scania county (Sweden) undergoing treatment with fixed orthodontic appliances were selected to participate, in the end 149 patients were included in the study. The patients were divided into two groups, one receiving a varnish of 7700 ppm fluoride (Fluor Protector S, Ivoclar Vivadent AG, Schaan, Liechtenstein) and one a placebo varnish. Pre- and post-treatment photos were taken and WSL was graded according to Gorelick index by two independent observers.  Results: No significant difference could be seen between the test and placebo group, neither on surface nor individual level. The results were based on both t-test and percentual calculations.  Conclusion: The null hypothesis could be accepted since no significant difference could be seen between the test or placebo group. Due to the loss of a number of patients, mainly because of loss in the original study and new exclusion criteria set by the authors, the results may have been conflicted. More research is therefore needed to draw any conclusions. / Syfte: Syftet med studien var att undersöka om det finns en effekt på förekomsten av white spot lesions (WSL) hos under- och överkäkens tänder när tänderna i överkäken behandlas med fluoridvarnish. Nollhypotesen sattes till att det inte finns någon skillnad mellan test- och placebogruppen i prevalens av WSL. Material och metod: Patienter från tre olika kliniker i Skåne deltog i studien, 149 av 182 deltagare fullföljde studien. Patienterna delades in i två grupper, en som fick ett fluoridvarnish med 7700 ppm fluorid (Fluor Protector S, Ivoclar Vivadent AG, Schaan, Liechtenstein) och en med placebovarnish. Kliniska foton togs innan samt efter behandling med fast apparatur som graderades och bedömdes enligt Gorelick-skalan för WSL av två oberoende observatörer. Resultat: Det fanns ingen signifikant skillnad mellan testgruppen och placebogruppen varken på individ- eller ytnivå. Resultatet baserades på både t-test och procentberäkningar. Slutsats: Nollhypotesen accepterades då ingen signifikant skillnad fanns mellan test- och placebogrupp. På grund av bortfall av patienter, både i originalstudien men även med anledning av exklusionskriterier satta för denna studie, kan resultatet ha påverkats. Mer forskning behövs därför för att dra några slutsatser.
20

Current Technology and Techniques in Re-mineralization of White Spot Lesions: A Systematic Review

Podray, Susan January 2012 (has links)
White Spot lesions are a common iatrogenic occurrence on patients who are treated with fixed orthodontic appliances. There is a dynamic chemical interaction between enamel and saliva at the tooth surface that allow a lesion to have phase changes involving demineralization of enamel and remineralization. This is due to calcium and phosphate dissolved in saliva that is deposited onto the tooth surface or removed depending on the surrounding pH. Caseinphosphopeptide-amorphous calcium phosphate (CPP-ACP) is gaining popularity in dentistry as a way to increase the available level of calcium and phosphate in plaque and saliva to improve the chemical gradient so that if favors remineralization. The aim of our investigation is to search the available current literature and formulate a recommendation for use of CPP-ACP in orthodontics. Publications from the following electronic databases were searched: PubMed, Web of Science, Cochrane Library and Science Direct. Searches from August 2010 to April 1st 2012 were performed under the terms "MI Paste OR Recaldent OR caseinphosphopeptide-amorphous calcium phosphate OR CPP-ACP or tooth mousse". The searches yielded 155 articles, These were reviewed for relevance based on inclusion and exclusion criteria. Articles with inappropriate study design or no outcome measures at both baseline and end point were also excluded. 13 articles were deemed of relevance with a high quality study design and were included in this study for evaluation. The current literature suggests a preventative treatment regimen in which MI Paste Plus is used. It should be delivered once daily prior to bed after oral hygiene for 3 minutes in a fluoride tray, throughout orthodontic treatment. It should be recommended for high risk patients determined by poor oral hygiene, as seen by the inability to remove plaque from teeth and appliances. This protocol may prevent or assist in the remineralization of enamel white spot lesions during and after orthodontic treatment. / Oral Biology

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