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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.
1

Development of methodologies for the assessment of oral prostheses

D'Arcy, Susan January 1998 (has links)
No description available.
2

Evaluation of endodontic treatment of teeth with apical periodontitis

Byström, Anders January 1986 (has links)
Apical periodontitis, an acute or chronic inflamination around the apex of the tooth, is caused by bacteria in the root canal. In Sweden the dentists devote around 10X of their total time to treating this disease. The treatment usually requires 3 to 5 sessions. The treatment may fail in up to 25X of the cases. In the present study various treatment regimens were evaluated. One hundred and forty singlerooted teeth with apical periodontitis were treated. The importance of mechanical instrumentation, irrigating solutions and antibacterial dressings in eliminating bacteria from the infected root canals was studied using bacteriological techniques. The healing of the apical periodontitis after treatment was followed for 2 to 5 years on recall radiographs. Bacteria were found in all 140 root canals at the beginning of the treatment. Most of these bacteria were anaerobes and they represented a restricted group of bacteria compared to the bacteria present at other sites in the oral cavity. Mechanical instrumentation with files and reamers in combination with saline irrigation reduced the number of bacterial cells in the root canal 100- to 1000-fold during one treatment session. Bacteria could be eliminated from about half the number of root canals if this treatment was performed at 4 sessions. Mechanical instrumentation and irrigation with 0.5X or 5X sodium hypochlorite solutions or with the 5X solution in combination with 15X EDTA solution wa3 more efficient and the bacteria were eliminated from about half the treated canals after one treatment session. The bacteria which persisted in the root canal after this treatment usually increased in number during the interval up to the next session and reached levels which were often as high as in the initial sample at the previous session. All bacteria persistent in the root canals after the previous treatment regimens were with 2 exceptions eliminated by dressing the root canals for 1 to 2 months with calcium hydroxide paste. Thirty-four out of 35 root canals treated at the first session with mechanical instrumentation, irrigation with sodium hypochlorite solution and dressed with calcium hydroxide paste were free of bacteria at the second session. Calcium hydroxide paste was superior to camphorated phenol and camphorated paramonochlorophenol as dressing. Healing of 79 out of the 140 treated teeth was followed for 2 to 5 years. The majority of the lesions healed completely or decreased in size in such a way that they could be expected to heal. There was no or only an insignificant decrease in the size of the lesions in 5 cases. In 2 of these cases bacteria were demonstrated in the periapical tissues and in a third case dentin chips. Periapical lesions may thus fail to heal in a few cases due to an establishment of bacteria outside the root canal, and in that site the bacteria are inaccessible to conventional endodontic treatment. The present study showed that treatment of the majority of infected non-vital teeth can be completed in only 2 sessions, if mechanical instrumentation, sodium hypochlorite irrigation and calcium hydroxide dressing are combined. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1986, härtill 5 uppsatser.</p> / digitalisering@umu
3

Softening Efficacy of Various Solvents on Gutta-percha and Root Canal Sealer

Boman, Andreas, Selvin, Jakob January 2016 (has links)
Solvents have been used in endodontic retreatment for a long time and the dissolving effect is well proven. Latterly chloroform has come in a bad light due to its possible carcinogenicity. Despite the negative health effect it is still used in dental environment. Other more biocompatible solvents have now reached the market and tests should be performed to evaluate the softening efficacy. The purpose of this in-vitro study was to evaluate the softening efficacy of four different solvents used in endodontics; chloroform, eucalyptol, tetrachloroethylene, orange-oil and a control group. 100 simulated canals filled with gutta-percha, epoxy amine resin based sealer, zinc oxide eugenol based sealer and non eugenolcalcium hydroxide based sealer were tested with hardness measurement before and after two minutes exposure time of medicament. Non-eugenol calcium hydroxide failed to set and was excluded from the test. A Shore A durometer was used to evaluate the hardness of the materials and all data was first analyzed with Kruskal-Wallis test and then Mann-Whitney test to compare with control group. With a digital camera connected to a microscope we also took pictures to compare the impressions with the different medicaments. The result showed that chloroform and tetrachloroethylene is significant better to soften gutta-percha than control group (p &lt; 0.05) but only chloroform significant better than control group to soften epoxy amine resin based sealer and zinc oxide eugenol based sealer (p &lt; 0.05). Even if the result was significant, we cannot draw any conclusions due to small sample size.
4

Ensaio sobre o uso da termografia infravermelha na avaliação da vitalidade pulpar in vivo / The use of infrared thermographic imaging for pulp vitality evaluation in vivo

Elias, Isabelle 08 October 2008 (has links)
Atualmente, sabe-se que determinar a vitalidade pulpar testando apenas a sua resposta sensorial nervosa, através de testes térmicos ou elétricos, é discutível, pois tais procedimentos não são suficientemente sensíveis para determinar, em definitivo, o real grau de envolvimento pulpar. Além disso, a vitalidade da polpa não depende apenas de seu suprimento nervoso, mas de seu suprimento sanguíneo. Outro fator a considerar com relação ao diagnóstico pulpar, deve-se à possibilidade da ocorrência de respostas pouco confiáveis em pacientes excessivamente ansiosos ao tratamento odontológico, independente do estímulo empregado e da intensidade do teste. O diagnóstico da vitalidade pulpar através de meios de mensuração da temperatura da coroa do dente, como a termografia infravermelha, que avalia a distribuição de temperatura num corpo através da radiação emitida pela sua superfície, surge como possibilidade para superar as desvantagens dos testes de sensibilidade, como a necessidade da estimulação, as variáveis decorrentes da espessura de dentinaesmalte dos dentes, a idade dos pacientes, a condição da estrutura dentária, entre outras. Esta pesquisa verificou a aplicabilidade da imagem infravermelha na análise da queda de temperatura produzida pelo teste térmico com gás refrigerante e a viabilidade como recurso semiotécnico para diagnóstico endodôntico. Para tal, foram analisados quatro dentes portadores de polpa vital e dois dentes tratados endodonticamente. A metodologia utilizada avaliou, através da imagem térmica, a temperatura da superfície coronária submetidos à queda de temperatura, com e sem a utilização do isolamento absoluto. Os resultados não mostraram diferença significante entre os dentes estudados, no que diz respeito à temperatura da superfície coronária e que a utilização do isolamento absoluto também não alterou os resultados. A metodologia proposta neste estudo mostrou-se altamente eficaz para a análise de mudanças térmicas na superfície dentária. No entanto, novos estudos devem ser realizados para que a termografia infravermelha possa se tornar um recurso viável para utilização em Endodontia. / Nowadays, it is known that the determination of the pulp vitality testing only its nerve sensorial response through thermal or electrical tests is discussable because those procedures are not sufficiently sensitive to determine the degree of pulp involvement. Besides the vitality of the pulp does not only depend on its nerve condition, but on its blood supply too. Another factor to consider during the pulp diagnostic, independently of the nature of stimulus or their intensity, is the possibility to occur non reliable responses in excessively anxious patients face to the dentistry treatment. The diagnosis of the pulp vitality by the measurement of the dental crown temperature such as the infrared thermography (which evaluates the temperature distribution in a body through the radiation emitted by its surface) arises as a possibility to overcome the sensitivity tests disadvantages, for example: the stimulation necessity, the variants due to the thickness of the dentin and enamel, the age, the condition of the dental structure and etc. This study evaluated the applicability of the infrared thermography test in the analysis of temperatures decline produced by thermal test using cold spray, and its viability as an aid for the endodontic diagnostic. Using thermal imaging, this methodology analyzed the temperature of the crowns surface of four teeth with vitality and two endodontically treated teeth when submitted to the cold test with and without the use of rubber dam. The results did not show a significant difference between teeth conditions with regard to the crowns surface temperature and the use of rubber dam did not affect these results. The proposed methodology used in this study showed to be highly efficient to analyzing the thermal changes on the dental surface; however new studies must be performed to turn infrared thermography a practicable aid into the endodontic practice.
5

Outcome of endodontic therapy in young permanent teeth

Bufersen, Saitah 20 July 2018 (has links)
The prevalence of pulpal involvement in young permanent teeth ranges between 0.3-36%. The outcome of Endodontic Therapy (ET) has not been widely studied in children and adolescents. Published studies that evaluated Endodontically Treated Teeth (ETT) in children and adolescents had results that varied tremendously. This variation could be due to the wide age range spanning from 6-18 years. Evaluating the predictors of survival, failure, and tooth retention between smaller subgroups within this age range may be relevant. AIM: To identify and assess variables associated with the outcome of ETT in 6-18 year old subjects stratified by age and to compare the results to the general population. METHODS: Retrospective chart review along with clinical follow up of subjects that received ET at BUGSDM between 2007-2015 at age 6-18 years. RESULTS: ET of the young permanent tooth resulted in 85% tooth survival and 91% retention. Patient age and tooth type were significantly related to survival and retention of ETT. CONCLUSIONS: Survival and retention of ETT observed among children and adolescents were similar to observations in adults. ET is more likely to survive when it is performed at an older age (15-18 years), or on an anterior tooth. This suggests that the longer ET is prevented through proper oral hygiene measures and preventive dental care, the better the likelihood of survival and retention of ETT in young patients.
6

Associação de hidrocloreto de polihexametileno guanidina e hidróxido de cálcio para uso como medicação intracanal

Paulus, Marília January 2017 (has links)
Objetivo: O objetivo do presente estudo foi desenvolver uma medicação intracanal contendo hidrocloreto de polihexametileno guanidina (PHMG) e hidróxido de cálcio Ca(OH)2, avaliando as suas propriedades e eficácia antimicrobiana. Métodos: O material foi formulado a partir da associação de 2% de PHMG ao pó de hidróxido de cálcio associado ao veículo propilenoglicol. O material foi avaliado pelos testes de análise antimicrobiana, escoamento, espessura de película, análise de pH e liberação de cálcio. Resultados: Os resultados foram analisados através do teste ANOVA de uma via, ANOVA de duas vias e teste tukey, com nível de significância de 5%. A atividade antimicrobiana com a associação de hidrocloreto de polihexametileno guanidina (PHMG) mostrou-se eficaz para Enterococcus faecalis. No teste de escoamento, o hidróxido de cálcio associado com o propilenoglicol mostrou um escoamento maior do que quando associado com o hidrocloreto de polihexametileno guanidina (PHMG) (p˂ 0,05). No teste de espessura de película os grupos não apresentaram diferença. Na análise de pH, os grupos variaram a alcalinidade nos tempos avaliados, durante o período de 28 dias (pH entre 7,5 – 11,5). Na liberação de cálcio, o uso do antimicrobiano hidrocloreto de polihexametileno guanidina (PHMG) não interferiu na liberação de cálcio do material. Conclusão: A adição de (PHMG) ao pó de hidróxido cálcio e ao veículo propilenoglicol não interferiu na liberação de cálcio, além de possuir efeito antimicrobiano, manteve o pH alcalino, não alterando a espessura de película, entretanto apresentou um menor escoamento do material. / Objective: The objective of the present study was to develop an intracanal medication containing polyhexamethylene guanidine hydrochloride (PHMG) and calcium hydroxide Ca (OH)2, evaluating its properties and antimicrobial efficacy. Methods: The material was formulated from the association of 2% PHMG with the calcium hydroxide powder associated with the propylene glycol vehicle. The material was evaluated by antimicrobial analysis, flow, film thickness, pH analysis and calcium release. Results: The results were analyzed through the one-way ANOVA, two-way ANOVA and tukey test, with a significance level of 5%. The antimicrobial activity with the combination of polyhexamethylene guanidine hydrochloride (PHMG) was shown to be effective for Enterococcus faecalis. In the flow test, the calcium hydroxide associated with propylene glycol showed a greater flow than when associated with polyhexamethylene guanidine hydrochloride (PHMG) (p<0.05). In the film thickness test, the groups showed no difference. In the pH analysis, the groups varied the alkalinity at the evaluated times, during the period of 28 days (pH between 7.5 - 11.5). In the release of calcium, the use of the antimicrobial polyhexamethylene guanidine hydrochloride (PHMG) did not interfere with the release of calcium from the material. Conclusion: The addition of (PHMG) to the calcium hydroxide powder and to the propylene glycol vehicle did not interfere with the release of calcium, besides having an antimicrobial effect, it maintained the alkaline pH, without altering the film thickness, however presented a lower material flow.
7

Observations of Trends and Successes of Revascularization Therapy at Virginia Commonwealth University: A Retrospective Study

Sedwick, Richard W 01 January 2018 (has links)
The aim of this study was to determine the trends in protocol, success rates, and consistency in follow up of revascularization procedures in a controlled environment. Patients of the Virginia Commonwealth University School of Dentistry were identified who were offered revascularization therapy as a treatment option on immature permanent teeth from January 1, 2010 to May 31, 2017. A total of 77 patients and 78 teeth were evaluated for revascularization therapy. For patients accepting treatment, records were reviewed for outcome assessment and consistency of follow up. A total of 30 patients (31 teeth) were treated following revascularization protocols, with only 20 patients (21 teeth) returning for follow up. Six of the 21 teeth needed some form of additional therapy due to patients remaining symptomatic, however 15/21 exhibited varying levels of success. Recall rate was 67.7%. With a success rate of 71.4%, revascularization therapy should continue to be considered for all patients with teeth having necrotic pulps and immature root apices. However, changes to recall protocols need to be improved in order to better monitor the status of teeth that undergo revascularization therapy.
8

Comparative efficacy of endodontic medicaments against Enterococcus faecalis biofilms.

Plutzer, Barbara January 2009 (has links)
It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009
9

Comparative efficacy of endodontic medicaments against Enterococcus faecalis biofilms.

Plutzer, Barbara January 2009 (has links)
It is well established that bacteria cause pulpal and periradicular disease (Kakehashi et al. 1965). Of the bacteria recovered from failing root canals, Enterococcus faecalis is one of the most prevalent species (Molander et al. 1998; Sundqvist et al. 1998). Many laboratory studies have investigated the effectiveness of root canal irrigants and medicaments against E. faecalis. Most used planktonic cultures, which are not representative of the in vivo growth conditions of an infected root canal system, where bacteria grow as a biofilm adhering to the dentinal wall (Nair 1987). Organisation of bacteria within biofilms confers a range of phenotypic properties that are not evident in their planktonic counterparts, including a markedly reduced susceptibility to antimicrobial killing (Wilson 1996). Objectives: The aims of this study were: 1) To compare the efficacy of commonly used endodontic medicaments against E. faecalis cultured as a biofilm. The medicaments tested were Ledermix paste, calcium hydroxide, Odontopaste, 0.2% chlorhexidine gel and 50:50 combinations of Ledermix/calcium hydroxide and Odontopaste/calcium hydroxide. 2) To compare the antimicrobial effect achieved through exposure to endodontic medicaments with that achieved by exposure to a constant concentration of sodium hypochlorite for varying times. Methods: A biofilm was established using a continuous flow cell. E. faecalis inoculum was introduced into the flow cell and allowed to establish on human dentine slices over 4 weeks. Each test medicament was introduced into the flow cell for a period of 24 or 48 hours, while sodium hypochlorite was evaluated after 1, 10, 30 and 60 minutes. Biofilms were harvested by sonication in sterile PBS. Cellular protein levels were measured to quantitate the amount of biofilm harvested. Cellular viability was determined using serial plating. The number of colony forming units was then adjusted for cellular protein levels to allow treatment protocols to be compared. Qualitative SEM analyses of the biofilm was performed following exposure to each test agent. Results: Sodium hypochlorite was the only agent that achieved total bacterial elimination. Ledermix and Odontopaste had no significant effect on the E. faecalis biofilm, while calcium hydroxide and 50:50 combinations of calcium hydroxide with either Ledermix or Odontopaste were able to reduce viability by > 99%. Conclusion: When used in isolation, antibiotic containing medicaments had no appreciable effect on the viability of Enterococcus faecalis. Sodium hypochlorite remains the gold standard for bacterial elimination in root canal therapy. / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 2009
10

Associação de hidrocloreto de polihexametileno guanidina e hidróxido de cálcio para uso como medicação intracanal

Paulus, Marília January 2017 (has links)
Objetivo: O objetivo do presente estudo foi desenvolver uma medicação intracanal contendo hidrocloreto de polihexametileno guanidina (PHMG) e hidróxido de cálcio Ca(OH)2, avaliando as suas propriedades e eficácia antimicrobiana. Métodos: O material foi formulado a partir da associação de 2% de PHMG ao pó de hidróxido de cálcio associado ao veículo propilenoglicol. O material foi avaliado pelos testes de análise antimicrobiana, escoamento, espessura de película, análise de pH e liberação de cálcio. Resultados: Os resultados foram analisados através do teste ANOVA de uma via, ANOVA de duas vias e teste tukey, com nível de significância de 5%. A atividade antimicrobiana com a associação de hidrocloreto de polihexametileno guanidina (PHMG) mostrou-se eficaz para Enterococcus faecalis. No teste de escoamento, o hidróxido de cálcio associado com o propilenoglicol mostrou um escoamento maior do que quando associado com o hidrocloreto de polihexametileno guanidina (PHMG) (p˂ 0,05). No teste de espessura de película os grupos não apresentaram diferença. Na análise de pH, os grupos variaram a alcalinidade nos tempos avaliados, durante o período de 28 dias (pH entre 7,5 – 11,5). Na liberação de cálcio, o uso do antimicrobiano hidrocloreto de polihexametileno guanidina (PHMG) não interferiu na liberação de cálcio do material. Conclusão: A adição de (PHMG) ao pó de hidróxido cálcio e ao veículo propilenoglicol não interferiu na liberação de cálcio, além de possuir efeito antimicrobiano, manteve o pH alcalino, não alterando a espessura de película, entretanto apresentou um menor escoamento do material. / Objective: The objective of the present study was to develop an intracanal medication containing polyhexamethylene guanidine hydrochloride (PHMG) and calcium hydroxide Ca (OH)2, evaluating its properties and antimicrobial efficacy. Methods: The material was formulated from the association of 2% PHMG with the calcium hydroxide powder associated with the propylene glycol vehicle. The material was evaluated by antimicrobial analysis, flow, film thickness, pH analysis and calcium release. Results: The results were analyzed through the one-way ANOVA, two-way ANOVA and tukey test, with a significance level of 5%. The antimicrobial activity with the combination of polyhexamethylene guanidine hydrochloride (PHMG) was shown to be effective for Enterococcus faecalis. In the flow test, the calcium hydroxide associated with propylene glycol showed a greater flow than when associated with polyhexamethylene guanidine hydrochloride (PHMG) (p<0.05). In the film thickness test, the groups showed no difference. In the pH analysis, the groups varied the alkalinity at the evaluated times, during the period of 28 days (pH between 7.5 - 11.5). In the release of calcium, the use of the antimicrobial polyhexamethylene guanidine hydrochloride (PHMG) did not interfere with the release of calcium from the material. Conclusion: The addition of (PHMG) to the calcium hydroxide powder and to the propylene glycol vehicle did not interfere with the release of calcium, besides having an antimicrobial effect, it maintained the alkaline pH, without altering the film thickness, however presented a lower material flow.

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