Thesis--University of Rochester, 1965.

Indiana University-Purdue University Indianapolis (IUPUI) / Objective: The objective was to assess a multiple emission peak light-emitting-diode (LED) light-curing unit (LCU) by measuring the polymerization efficiency through the degree of conversion (DC) and Knoop microhardness (KHN) of a resin-based pit and fissure sealant at various light curing times and two distances compared to a single emission peak LED LCU. Method: Sixty disks of resin-based pit and fissure sealant (Delton, DENTSPLY, York, PA) samples (6x1mm) were fabricated (n=5/LCU/group). Prepared samples were polymerized using 10, 20 and 40 second curing time at 2 or 4 mm curing distances. The irradiance and radiant exposure received on the top/bottom surfaces of the samples were measured using the Managing Accurate Resin Curing-Resin Calibrator (MARC-RC) system. The samples were stored at 37°C for one hour. Then, the DC (n=3/surface) and KHN (n=5/surface) measurements were collected on the top and bottom surfaces using Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and a microhardness tester (Instron) utilizing 25-gm at 10 seconds dwell time, respectively. Multiple-way ANOVA was performed followed by Tukey test (α=0.05). Result: The irradiance from the multiple emission peak LED LCU was significantly higher than the single emission peak LED LCU (1312.6 and 768.3 mW/cm2) respectively. Moreover, the multiple emission peak LED LCU displayed significantly higher DC (82.5%) and microhardness (26.2 KHN) compared to the single emission peak LED LCU (75.5% DC and 21.2 KHN) when curing samples at 2 and 4 mm curing distances assessed using 10, 20 and 40-second curing times. The 10 second cure at 4 mm showed significantly lower DC and KHN values compared to the other groups. Conclusion: The multiple emission peak LED LCU demonstrated significantly higher irradiance, DC and KHN compared to the single emission peak LED LCU on a resin-based pit and fissure sealant at 2 and 4 mm curing distances and 10, 20 and 40 second curing times. Therefore, the multiple emission peak LED LCU performed higher than the single emission peak LED LCU.

Indiana University-Purdue University Indianapolis (IUPUI) / The concepts of using a pit and fissure sealant material to prevent dental caries have been well established in dental research. Effectiveness of a pit and fissure sealant material is limited to its ability to remain bonded to the occlusal surfaces. Adding a dentin-bonding agent between the etched enamel and the sealant material has been demonstrated as a way of optimizing bond strength in the face of moisture and salivary contamination. The purpose of this study was to examine if there was a difference in fissure penetration or microleakage between a conventional pit and fissure sealant or a flowable composite when used as a pit and fissure sealant, while using three different adhesive systems. Delton Direct Delivery System (Dentsply), an opaque, light cured pit and fissure sealant and the commercially available flowable composite, Revolution Formula 2 (Kerr) was selected for this study. Three clinically used adhesive systems selected for this study were: conventional phosphoric acid etching; Opti-bond Solo Plus(Kerr), a single bottle system; and Prompt L-Pop (3M ESPE), an all-in-one primer adhesive. One hundred fifty extracted caries-free third molars, selected for well-defined occlusal pits, were randomly divided into six treatment groups. Fissure penetration and microleakage was examined after immersion of the treated teeth in 5.0-percent methylene blue solution for 18 hours; the teeth were removed and thoroughly cleaned. Mesial and distal flat-ground sections were obtained and examined at X20; microleakage was recorded as either present or absent, and penetration was recorded as either complete or incomplete. The interaction between the material and the adhesive system was non-significant based on the logistic regression model for the penetration and the microleakage, so that only the main effects of material and adhesive system were included in the final model. Enamel conditioning with the total-etch and single-bottle adhesive system provided consistently microleakage resistance when compared with the use of the all-in-one bonding system. The all-in-one adhesive system demonstrated the most microleakage regardless of the material used for the pit and fissure sealant. The hypothesis of this thesis was that there would be no significant difference in fissure penetration or microleakage between the conventional pit and fissure sealant or the flowable composite, regardless of the adhesive system used. The results of this study support the hypothesis that there was no significant difference in fissure penetration between the materials. The result did demonstrate that there was significant difference in microleakage between the three different adhesive systems used.

Indiana University-Purdue University Indianapolis (IUPUI) / The concepts of using a pit and fissure sealant material to prevent dental caries have been well established in dental research. Effectiveness of a pit and fissure sealant material is limited to its ability to remain bonded to the occlusal surfaces . Adding a dentin-bonding agent between the etched enamel and the sealant material has been demonstrated as a way of optimizing bond strength in the face of moisture and salivary contamination. The purpose of this study was to examine if there was a difference in fissure penetration or microleakage between a conventional pit and fissure sealant or a flowable composite when used as a pit and fissure sealant, while using three different adhesive systems. Delton Direct Delivery System (Dentsply), an opaque, light cured pit and fissure sealant and the commercially available flowable composite, Revolution Formula 2 (Kerr) was selected for this study. Three clinically used adhesive systems selected for this study were: conventional phosphoric acid etching; Opti-bond Solo Plus(Kerr), a single bottle system; and Prompt L-Pop (3M ESPE), an all-in-one primer adhesive. One hundred fifty extracted caries-free third molars, selected for well-defined occlusal pits, were randomly divided into six treatment groups. Fissure penetration and microleakage was examined after immersion of the treated teeth in 5.0-percent methylene blue solution for 18 hours; the teeth were removed and thoroughly cleaned. Mesial and distal flat-ground sections were obtained and examined at X20; micro leakage was recorded as either present or absent, and penetration was recorded as either complete or incomplete. The interaction between the material and the adhesive system was non-significant based on the logistic regression model for the penetration and the microleakage, so that only the main effects of material and adhesive system were included in the final model. Enamel conditioning with the total-etch and single-bottle adhesive system provided consistently microleakage resistance when compared with the use of the all-in-one bonding system. The all-in-one adhesive system demonstrated the most microleakage regardless of the material used for the pit and fissure sealant. The hypothesis of this thesis was that there would be no significant difference in fissure penetration or microleakage between the conventional pit and fissure sealant or the flowable composite, regardless of the adhesive system used. The results of this study support the hypothesis that there was no significant difference in fissure penetration between the materials. The result did demonstrate that there was significant difference in microleakage between the three different adhesive systems used.

Thesis (M.S.D.)--Indiana University School of Dentistry, 2009. / Title from PDF t.p. (viewed Feb. 5, 2010) Advisor(s): Michael A. Cochran, Chair of the Research Committee, Armando E. Soto Rojas, Margherita R. Fontana, Timothy Carlson, Tien-Min Gabriel Chu. Curriculum vitae. Includes abstract. Includes bibliographical references (leaves 56-61).

Thesis (M.S.)--School of Dentistry. University of Missouri--Kansas City, 2008. / "A thesis in oral biology." Advisor: Mary P. Walker. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Aug. 07, 2009. Includes bibliographical references (leaves 39-45). Online version of the print edition.

Made available in DSpace on 2014-06-11T19:33:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-06Bitstream added on 2014-06-13T20:24:31Z : No. of bitstreams: 1 vieira_aem_dr_araca.pdf: 862313 bytes, checksum: 73131cab7febe9ed9ca73177596b76b0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Bisco Inc., Il, Usa / Bosworth Company, Il, Usa / O presente trabalho avaliou a capacidade da microtomografia de raios-X (XMT) laboratorial e síncrotron para mensurar coeficientes de absorção linear em escala micrométrica em estudos in vitro utilizando dentes bovinos e ciclagem de pH. Sendo assim, este estudo foi desenvolvido em cinco manuscritos, com os seguintes objetivos: traçar parâmetros e determinar um protocolo para a quantificação do conteúdo mineral de esmalte bovino utilizando XMT laboratorial e síncrotron; analisar a estrutura da junção amelo-dentinária em incisivos bovinos utilizando XMT síncrotron; determinar o potencial anti-cárie do fosfato de cálcio amorfo (ACP) presente em selantes de fóssulas e fissuras, utilizando dentes bovinos, ciclagem de pH, microdureza de superfície e XMT síncrotron; e avaliar, através de análise de microdureza de superfície e XMT síncrotron, a capacidade de uma pasta contendo CPP-ACP para ativar a remineralização do esmalte dental. Os resultados obtidos mostram que: a XMT propiciou a determinação da quantidade mineral com uma precisão mais adequada, sendo a melhor resolução espacial obtida através da luz síncrotron; a junção amelo-dentinária apresentou-se menos mineralizada que a dentina ou esmalte; o fosfato de cálcio amorfo presente nos materiais testados não foi capaz de inibir a desmineralização ou ativar a remineralização do esmalte bovino, em ciclagem de pH, tanto quanto os íons flúor. Conclui-se que a XMT é capaz de determinar pequenas alterações na mineralização do dente bovino após ciclagem de pH. / This study evaluated the ability of laboratory and synchrotron X-ray microtomography (XMT) for measuring linear attenuation coefficient at micrometer scale of in vitro studies using bovine teeth and pH-cycling. For that, this study included five papers, with the following aims: to define parameters and a protocol for quantification of mineral content of bovine enamel using laboratory and synchrotron XMT; to analyze the dentinoenamel junction (DEJ) structure in bovine incisors using synchrotron XMT; to determine the anti-caries potential of amorphous calcium phosphate (ACP) in pit and fissure sealants, using bovine teeth, pH-cycling, surface hardness and synchrotron XMT; and to evaluate, through surface hardness analysis and synchrotron XMT, the ability of a CPP-ACP paste to enhance enamel remineralization. The results showed that: XMT provided mineral quantification with an adequate precision; synchrotron microtomography provided the best spatial resolution; DEJ was less mineralized on the average than dentin or enamel; addition of ACP to the materials did not inhibit demineralization or enhance remineralization of bovine enamel in a pH-cycling as fluoride ions. It was possible to conclude that XMT can determine small alterations in the mineralization of bovine tooth after pH-cycling.

Orientador: Alberto Carlos Botazzo Delbem / Banca: Robson Frederico Cunha / Banca: Cássia Cilene Dezan Garbelini / Banca: Cínthia Pereira Machado Tabchoury / Banca: Célio Percinoto / Resumo: O presente trabalho avaliou a capacidade da microtomografia de raios-X (XMT) laboratorial e síncrotron para mensurar coeficientes de absorção linear em escala micrométrica em estudos in vitro utilizando dentes bovinos e ciclagem de pH. Sendo assim, este estudo foi desenvolvido em cinco manuscritos, com os seguintes objetivos: traçar parâmetros e determinar um protocolo para a quantificação do conteúdo mineral de esmalte bovino utilizando XMT laboratorial e síncrotron; analisar a estrutura da junção amelo-dentinária em incisivos bovinos utilizando XMT síncrotron; determinar o potencial anti-cárie do fosfato de cálcio amorfo (ACP) presente em selantes de fóssulas e fissuras, utilizando dentes bovinos, ciclagem de pH, microdureza de superfície e XMT síncrotron; e avaliar, através de análise de microdureza de superfície e XMT síncrotron, a capacidade de uma pasta contendo CPP-ACP para ativar a remineralização do esmalte dental. Os resultados obtidos mostram que: a XMT propiciou a determinação da quantidade mineral com uma precisão mais adequada, sendo a melhor resolução espacial obtida através da luz síncrotron; a junção amelo-dentinária apresentou-se menos mineralizada que a dentina ou esmalte; o fosfato de cálcio amorfo presente nos materiais testados não foi capaz de inibir a desmineralização ou ativar a remineralização do esmalte bovino, em ciclagem de pH, tanto quanto os íons flúor. Conclui-se que a XMT é capaz de determinar pequenas alterações na mineralização do dente bovino após ciclagem de pH. / Abstract: This study evaluated the ability of laboratory and synchrotron X-ray microtomography (XMT) for measuring linear attenuation coefficient at micrometer scale of in vitro studies using bovine teeth and pH-cycling. For that, this study included five papers, with the following aims: to define parameters and a protocol for quantification of mineral content of bovine enamel using laboratory and synchrotron XMT; to analyze the dentinoenamel junction (DEJ) structure in bovine incisors using synchrotron XMT; to determine the anti-caries potential of amorphous calcium phosphate (ACP) in pit and fissure sealants, using bovine teeth, pH-cycling, surface hardness and synchrotron XMT; and to evaluate, through surface hardness analysis and synchrotron XMT, the ability of a CPP-ACP paste to enhance enamel remineralization. The results showed that: XMT provided mineral quantification with an adequate precision; synchrotron microtomography provided the best spatial resolution; DEJ was less mineralized on the average than dentin or enamel; addition of ACP to the materials did not inhibit demineralization or enhance remineralization of bovine enamel in a pH-cycling as fluoride ions. It was possible to conclude that XMT can determine small alterations in the mineralization of bovine tooth after pH-cycling. / Doutor

Indiana University-Purdue University Indianapolis (IUPUI) / This clinical study investigated the efficacy of the new LED LCU technology when compared to that of the QTH LCU by evaluating retention and wear of Clinpro (3M ESPE) sealant material over six months of function. This study was designed as a split mouth, randomized clinical study. Sealants were placed and polymerized on contralateral teeth of 35 patients, 33 of which successfully completed the study. The sealants were evaluated for clinical retention at baseline, three months, and six months by two evaluators. For the wear analysis, the area of the sealant wear at six months is reported. Nine pairs of molars and 22 pairs of premolar teeth were used. This sample size is smaller than the original sample used for clinical evaluation, because a number of the baseline impressions had to be discarded due to poor impression quality. Subsequent impressions were taken at three months, and six months. Epoxy replicas were made from the impressions and the occlusal surface of each replica was digitized using SigmaScan software. A cummulative legit model was applied to the clinical data, and a linear model was applied to the wear analysis. The results for clinical retention over the six months of function were as follows. At Baseline, for the QTH, 97.3 percent of the teeth received an Alpha score; 2.7 percent received a score of B. For the LED, 87.7 percent received a score of A; 12.3 percent received a score of B. At three months follow-up, for the QTH, 93.1 percent received a score of A; 6.9 percent received a score of B. For the LED, 86.1 percent received a score of A; 12.5 percent received a score of B, and 1.14 percent received a score of C. At six months follow-up, for QTH; 91.7 percent received a score of A; 8.3 percent received a score of B. For the LED, 83.3 percent received a score of A; 15.3 percent received a score of B, and 1.14 percent received a score of C. The hypothesis was that there would be no significant difference in clinical retention and wear of Clinpro's sealant polymerized with the QTH or the LED light sources over six months of function. Based on the results of this clinical study, the following conclusions can be made: 1) At baseline, Clinpro's sealant polymerized with QTH light source showed marginally significant better retention than LED light source (p-value 0.05001). 2) There was no significant difference between light sources for sealant clinical retention at three-month and six-month follow up visits. 3) Wear analysis resulted in marginally significant more wear for molar sealants polymerized with LED LCU (p-value 0.0755). 4) Wear analysis showed no significant difference for premolar sealants polymerized with either light source.

Magister Scientiae Dentium - MSc(Dent) / BACKGROUND: The application of dental sealants is a recommended procedure to prevent and control dental caries. However, despite strong evidence for the safety and effectiveness of dental sealants, their use still remains low, especially among children from lower socioeconomic communities. The World Health Organization (WHO), Centres for Disease Control and Prevention (CDC) and the Association of State and Territorial Dental Directors (ASTDD) strongly endorse the implementation of school based dental sealant programmes as a community-based preventive strategy to increase sealant use and reduce dental caries. However, in the WHO African Region, oral health is seen as a very low priority and this is compounded by limited technical and managerial resources. The availability of human resources and equipment are crucial for the successful placement of dental sealants. A gap in the research literature was identified for determining the effectiveness of fissure sealants placed under field conditions. AIM: To evaluate the caries preventive effect as well as retention status of a resin-based fissure sealant that was placed under field conditions as part of a school based sealant programme. METHODOLOGY: A cross-sectional comparative study was conducted at two primary schools in close proximity of each other in the same low socio-economic area in Beaufort West, South Africa. The study population consisted of grade two children between the ages of 7-9 years who had fully erupted first permanent molar teeth. The case group consisted of 100 learners who received dental sealants on caries-free first permanent molar teeth 12 months earlier. The control group consisted of a random selection of the same number of learners from the adjacent school. Dental caries on the occlusal surfaces of the first permanent molar teeth was detected by making use of the decayed (D) portion of the decayed, missing and filled tooth (DMFT) score, while a separate diagnosis distinguished between cavitated and non-cavitated lesions. Sealant retention was determined by a calibrated examiner who was not involved in the placement of the sealants. RESULTS: The response rate of the study was 80.0% (n=100) and 78.9% (n=356) of the fissure sealants that were originally placed were evaluated. When the sealants were placed in 2013, 52.0% of the children were female and at the 12 month follow-up, 51.3% were female. The average age of the female children at follow-up was 8 years and 4 months (99.9 months) and 8 years and 5 months (101.8 months) for the males. The standard deviation of the gender profiles differed by 1 month only and implies an equal distribution of age between female and male children throughout the study. Just less than ten per cent (7.8%) of the sealants were fully intact at the 12 month follow-up examination and 91% were totally lost, which is a higher sealant loss rate than what is generally reported on in the literature. Of the 7.8% fully retained sealants, a statistically significant proportion (p=0.044) were found on the mandibular molar teeth. The caries incidence rate in the sealed group was 7.1% versus 9.1% in the control group. Relative risk (RR) calculations was slightly lower for the sealed (RR=0.79) than the unsealed (RR=1.02) teeth. CONCLUSION: The study showed a 2% lower caries prevalence rate on the occlusal surfaces of the sealed versus the unsealed teeth. However, this does not represent a statistically significant finding (P=0.39). The study also showed a low retention rate for the resin-based sealants placed under field conditions (12 month retention rate of 7.8%). The results from this study has therefore shown that resin-based fissure sealants placed on grade 1 learners under field conditions appear to be not ideal in preventing the onset of dental caries on the occlusal surfaces of the first permanent molar teeth.