Magister Scientiae - MSc / The purpose of this in vitro study is to compare the relative retentive strength of conventional amalgam restorations and bonded amalgam restorations using resin adhesive, glass ionomer cements and resin cements.

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Thesis (doctoral)--Radbound University Nijmegen, Netherlands, 2007. / Includes bibliographical references.

Today it is possible to create veneers that are aesthetically and functionally satisfying, but there are some factors that may compromise the aesthetic results.  The aim of this study was to investigate influence of cement shades and ceramic thickness on the colour of ceramic veneers, but also to study how well try-in pastes match with their corresponding cements. PubMed was used to search for papers using MeSH-terms and keywords. 144 titles and abstracts were read, 29 full texts were read and 24 papers were used in the analysis. All of the studies were in vitro. In 20 studies, it was found that the cement shade influences the colour of the ceramic veneer. Two studies reported that the cement shade had no influence on the colour of ceramic veneers, and two did not draw any conclusions regarding the influence of cement shade. Twelve studies compared different thicknesses of the veneers; all of them found that the thicknesses had an influence on the colour of the veneers. Two out of four studies found no compatibility between try-in pastes and their corresponding cements, while two studies found compatibility for some try-in pastes. The shades of cement and thicknesses of ceramic veneers can influence the colour of the ceramics. The colour of try-in pastes does not always show a similarity with their corresponding cement.

Orientador: Jose Flavio Affonso de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T12:52:16Z (GMT). No. of bitstreams: 1 Pantoja_CarlosAugustodeMoraisSouto_M.pdf: 2858833 bytes, checksum: 4b87be3f5537ab9d2fa29c4224c00b74 (MD5) Previous issue date: 2010 / Resumo: O presente estudo avaliou a influência de 04 técnicas obturadoras e 03 marcas de cones de guta-percha no preenchimento e selamento de canais laterais artificiais, e a porcentagem do polímero guta-percha nos diferentes cones. Foram confeccionados canais laterais nos terços médio e apical de 120 dentes humanos anteriores superiores, que tiveram suas coroas removidas. Os canais radiculares foram instrumentados e as raízes distribuídas aleatoriamente em 12 grupos (n=10): GI - Condensação Lateral (CL)/Konne (K), GII - CL/Autofit (A), GIII - CL/Dentsply (D), GIV - Híbrida de Tagger (HT)/K, GV - HT/A, GVI - HT/D, GVII - Onda Contínua de Condensação (OCC)/ K, GVIII - OCC/A, GIX - OCC/D, GX - Schilder (S)/K, GXI - S/A e GXII - S/D. As amostras foram obturadas, radiografadas para mensuração do preenchimento nos canais laterais, infiltradas e diafanizadas. Após a captura das imagens, foram avaliados o preenchimento (cimento/cone de guta-percha), a infiltração e a penetração da guta-percha no interior ramificações artificiais. Foi realizada a análise da composição química dos cones de guta-percha e diante da concentração encontrada verificou-se maior porcentagem do polímero guta-percha nos cones Konne, seguidos dos Autofit e Dentsply. Os valores de preenchimento (cimento/cone de guta-percha) e de infiltração não demonstraram diferença significativa, entre os grupos experimentais. Maior penetração da guta-percha nos canais laterais pôde ser observada com o emprego dos cones da marca Konne em relação aos Dentsply, para todas as técnicas obturadoras, exceto a Condensação Lateral. Os cones Autofit e Dentsply apresentaram bons resultados, quando associados à Técnica Híbrida de Tagger. As imagens radiográficas e da diafanização mostraram correlação fraca positiva no preenchimento dos canais laterais para o terço médio e ausência de correlação para o terço apical. Embora as técnicas termoplastificadoras tenham demonstrado bons resultados para a penetração da guta-percha no interior dos canais laterais, o preenchimento com cimento/cone de guta-percha e a infiltração ocorrida nos canais laterais artificiais não apresentaram diferenças significativas entre as técnicas e cones utilizados / Abstract: This study evaluated the influence of 04 filling techniques and 03 brands of guttapercha cone for filling and sealing of artificial lateral canals, and the percentage of guttapercha in the different brands. Lateral canals were prepared in the middle and apical thirds of 120 human maxillary anterior teeth, which had their crowns removed. The root canals were instrumented and the roots randomly into 12 groups (n = 10): GI - lateral condensation (LC) / Konne (K), GII - CL / Autofit (A), GIII - CL / Dentsply (D), GIV - Tagger's hybrid (HT) / K, GV - HT / A, GVI - HT / D, GVII - Continuous Wave Condensation (OCC) / K, GVII - OCC / A, GIX - OCC / D, GX - Schilder (S) / K, GXI - S / A and GXII - S / D. Once filled and radiographed in order to measure the filling (cement / gutta-percha cone) the lateral canals, the roots were infiltrated and cleared and after the capture of images was assessed filling (cement / cone of gutta-percha) the infiltration and penetration of gutta-percha within the side channels. It was used to analyze the chemical composition of gutta-percha cone and after the concentration found there was a higher percentage of gutta-percha cones Konne, followed by and Autofit Dentsply. The values of filling (cement / cone of gutta-percha) and infiltration showed no significant difference between the experimental groups. Increased penetration of gutta-percha in lateral canals could be observed with the use of cones Konne for all root canal filling techniques, except the lateral condensation. The cones and Autofit Dentsply had good results, when combined with the Tagger's hybrid technique. The radiographic images and cleared roots showed a weak positive to fill the side channels for the middle third, and no correlation to the apical third. Although thermoplasticized technique have shown good results for the penetration of gutta-percha within the lateral canals, filling with cement / cone of gutta-percha and infiltration occurred in the lateral canals were not significantly different between the techniques used and cones / Mestrado / Endodontia / Mestre em Clínica Odontológica

OBJECTIVE: This study aims to compare the flexural strength and color stability of conventional, machined, and printed dental polymers. Secondarily, the effects of aging, fatigue, coffee, distilled water, and UV light on the color stability and flexural strength of the different dental polymers will be evaluated. MATERIALS AND METHODS: Sixty disks 14mm in diameter and 2mm in thickness were fabricated from each of the following polymers: Jet Tooth Shade (Lang Dental), ProTemp (3M-ESPE), Telio CAD Temp (Ivoclar Vivadent), Vita CAD Temp (Vita), Temporary CB (FormLab), Dentca (Dentca), and Bego VarseoSmile Crown Plus (Bego). The sixty disks from each polymer were then divided into the six following groups: no treatment, thermocycling, fatigue, thermocycling and coffee, distilled water and finally UV Light. Prior to any treatment, the color coordinates CIE L*a*b*, were registered first. The non-treated groups were fractured using the Instron Universal Testing Machine to obtain flexural strength values. Thermocycling consisted of placing the specimens in 30 seconds 5°C water and then 30 seconds in 55°C water for 5,000 cycles. Fatigue testing consisted of cyclic loading the disk specimens by calculating 60% of the mean load to failure from the non-treated group and subjecting them to 50,000 cycles. The third group was placed under thermocycling for 1,500 cycles and then placed in coffee for 15 days. Another group was placed in distilled water for 15 days. Finally, the UV light treatment consisted of exposing the disk specimens to UV light for ten hours over the course of five days. After treatment, the color coordinates were recorded again and fractured using the Instron Universal Testing Machine. The data was analyzed for any statistically significant differences using ANOVA with a<0.05. RESULTS: The flexural strength values were highest for Telio CAD Temp, that was affected only by UV light via a statistical analysis. ProTemp was second highest followed by Bego VarseoSmile Crown Plus, Dentca, Temporary CB, Vita CAD Temp and finally Jet Tooth Shade. Color differences were highest for Dentca followed by Jet Tooth Shade, ProTemp, Telio CAD Temp, Temporary CB and finally Vita CAD Temp. UV light and thermocycling/ coffee had the highest impact. CONCLUSION: Telio CAD Temp had the highest overall flexural strength and was resistant to all post fabrication treatments except for UV light. ProTemp had the second highest overall flexural strength but was susceptible to multiple post fabrication treatments like distilled water, fatigue, and aging. The printed specimens had flexural strength values lower in the middle range of all tested materials. In terms of treatment, UV light and coffee/thermocycling had the biggest impact on the overall color stability values. Powder and Liquid based PMMA had the lowest overall flexural strengths.

Abstract Introduction: Patients with numerous crowns and bridges are at risk of developing secondary caries on cervical margins of the crowns. This recurrent decay accounts for 60% of the reasons for the replacement of restorations. Detection and treatment of subclinical lesions is important to prevent cavitation. An alginate impression material has been used to locate cariogenic bacteria in established carious lesions. Aims: An alginate impression technique was used to assess the level of Streptococcus mutans and Lactobacilli on the crown margins of the teeth of the restored group and control subjects. Conventional caries activity tests were also used to compare these two groups. Methods: Twenty control group subjects with no crowns and a mean DMFS of 16 and 20 the restored group patients with at least 10 crowns and a mean DMFS of 129 were included in the study. Impressions were taken with a hydrocolloid material mixed with culture broth, incubated and examined for the presence of S. mutans and Lactobacilli on the cervical margins. The results were compared using the two-sample t-test, chi-squared test and a generalized logistic regression analysis. Results: More S. mutans and Lactobacilli were cultured on impressions of the restored group than the control patients (p=0.01 and 0.002). A higher proportion of patients in the restored group had high concentrations of S. mutans and Lactobacilli on their teeth than subjects in the control group (p < 0.001). In the restored group, sixty six per cent of teeth in the posterior and 48% in the anterior segment were crowns. S. mutans and Lactobacilli were found in higher concentrations on the posterior than the anterior teeth of the restored group patients than the control patients (p = 0.016 and 0.047). Furthermore, more Lactobacilli were cultured from the saliva of the restored group than control subjects while the buffering capacity of plaque and the ability of saliva to neutralize acids were lower in the restored group than control group subjects. Conclusion: The impression technique showed that S. mutans and Lactobacilli accumulated in the posterior of the mouth and were associated with crowns indicating these particular sites are at risk.

To determine the effects of thermal accelerated aging on flexural strength and flexural modulus of conventional and CAD/CAM provisional crown and bridge restorative materials. Six provisional crown and bridge materials were selected for this study. Three conventional resins: Jet Set 4 (Lang), Luxatemp (DMG), and Protemp Plus (3M ESPE); and three CAD/CAM materials: ArtBloc Temp (Merz), Telio CAD-Temp (Ivoclar Vivadent), and Vita CAD-Temp (Vita). Specimens of conventional materials were fabricated using a custom-made aluminum mold 25 2 2 mm. CAD/CAM blocks were sectioned to the same dimensions. A total of 180 bar-shaped specimens were obtained (30 of each material) and were divided into three groups per treatment. Groups 1 and 2 were immersed in 37°C water for 24 hours, and 6 days, respectively. Group 3 was subjected to 5,000 thermal cycles between 5°C and 55°C in water with 35 seconds dwelling time. All specimens where tested for flexural properties using three-point bending protocol on an Instron 5566A at a crosshead speed of 0.5mm/min. The results were analyzed by one-way ANOVA and post hoc Tukey test with material type and aging conditions as the main variables. Significance level was set at (p<0.05).  Overall CAD/CAM materials demonstrated significantly higher flexural strength and flexural modulus over conventional resins. No significant difference in flexural strength and flexural modulus was found among three treatments except for: Luxatemp, which showed significant increased flexural strength and flexural modulus after thermal cycling, and Protemp Plus which showed increased flexural strength after 6 days of water storage.

Cracked teeth may be difficult to diagnose. Craze lines rarely become symptomatic or require treatment. Cracks in the enamel and dentin alone may or may not become symptomatic and require restorative treatment. However, cracks extending into the enamel, dentin, and pulp chamber provide an avenue for bacteria to establish infection and this commonly results in symptoms and the need for endodontic and restorative treatment. The published endodontic literature has limited information regarding the prevalence or predictive factors for cracks extending into the pulp chamber of teeth. The purpose of this study was to determine the prevalence and classification of intrapulpal cracks in maxillary premolars and to identify factors that may aid in diagnosing the existence and extent of a crack. The cracks were classified according to the Intrapulpal Crack Classification System proposed by Detar in 2014. All maxillary premolar teeth treatment planned for non-surgical root canal therapy (NSRCT) or retreatment (RETX) at Virginia Commonwealth University (VCU) Graduate Endodontic Practice from January 2014 through February 2015 were included in the study after obtaining patient consent. Teeth were examined visually, stained, and examined microscopically for the presence of an intrapulpal crack. Demographic information, subjective data associated with the chief complaint, objective results of diagnostic testing (percussion, palpation, bite stick test, transillumination, probing depths), existing restorations, pulpal diagnosis, and periapical diagnosis were analyzed using chi-square and multiple logistic regression (P