Fracture resistance of endodontically treated premolars restored with CAD-CAM onlays.

PURPOSE: To evaluate the fracture resistance of endodontically treated premolars restored with CAD-CAM onlay restorations. METHODS: 60 extracted mandibular first premolars were selected and at first divided into three groups regarding treatment options: MOD onlay with buccal cusp coverage, MOD onlay with buccal cusp coverage + endodontic treatment, MOD onlay with buccal cusp coverage + endodontic treatment + fiber post. Then, all groups were divided into subgroups (n=10) according to the restorative material used: IPS e.max CAD and Lava Ultimate. Each group was submitted to 5,000 thermal cycles, embedded in acrylic resin and secured in a universal testing machine respectively. A compressive load was applied until fracture, at a crosshead speed of 0.5 mm/minute. Statistical significance among each group was analyzed using one-way ANOVA and Bonferroni tests. RESULTS: Statistically, endodontically treated IPS e.max onlays had numerically the lowest average fracture resistance [753.1 (± 224.9) N/mm² ] among all treatment options. IPS e.max onlays treated with fiber posts had significantly higher resistance than that of endodontically treated IPS e.max CAD group (P= 0.013). Endodontically treated teeth restored with Lava Ultimate onlays [1,381.0 (± 471.7) N/mm²] showed significantly higher averages of fracture resistance than IPS e.max CAD onlays. CLINICAL SIGNIFICANCE: CAD-CAM composite (resin nanoceramic) onlays resist greater forces compared to ceramic restorations. Fiber posts could improve the fracture resistance of endodontically treated mandibular premolars following the ceramic CAD-CAM onlays.

Comparative evaluation of a fissure sealant and a flowable composite: A 36-month split-mouth, randomized clinical study.

OBJECTIVES: The purpose of the present clinical evaluation was to investigate the effect of a fissure sealant and a flowable composite at fissures of permanent molars in terms of retention and caries-incidence rates over a 36-month period. METHODS: Thirty-four patients, ages varied from 16 to 22 years, diagnosed with at least 2 non-cavitated pit-and-fissure caries in the first and second molars were involved in the study. A total of 220 sealants, were placed in 117 upper molars and 103 lower molars. Teeth were sealed with either a flowable resin composite (Tetric Evo Flow) or a sealant material (Helioseal F)(n = 110). Each restoration was evaluated in terms of retention and caries incidence at 6, 12, 24 and 36 months according to their location as well. Data were analyzed using Mann-Whitney U, Friedman and 1-way ANOVA tests at p < 0.05. RESULTS: Tetric Evo Flow showed total retention with 95.5%, 93.8%, 88.5% and 80.2% at 6, 12, 24 and 36-month follow-ups respectively, while Helioseal F had retention rates of 95.5%, 94.8%, 85.4% and 80.2% respectively. After 36-months, there were 6 subjects totally lost in Helioseal F group, whereas 7 of the Tetric Evo Flow sunjects were totally lost. Caries development was firstly detected at 12-month evaluation for both of the materials however, no significant differences were observed among materials in retention rates or caries incidence after 36-month follow-ups (p > 0.05). SIGNIFICANCE: Using the flowable composite found as effective as the fissure sealant after 36-months regarding retention and caries incidence rates.

Comparison of restorative materials and surface alterations after prebiotic and probiotic beverages: A nanoindentation and SEM study.

The purpose was to investigate the surface characteristics of various resin-based materials by immersing in probiotic beverages. A total of 420 disc-shaped samples (5 mm × 2 mm) were prepared from resin-based composites. Samples were divided into four groups and immersed for 10 min/day for 1 month in either a probiotic sachet, kefir, kombucha, or artificial saliva (control). Surface roughness was measured at baseline and 1 month. One sample of each of the tested materials was examined under nanoindentation to evaluate the reduced elasticity modulus and nanohardness scores. Scanning electron microscopy (SEM) was used to compare surface differences. Data were analyzed statistically using one-way ANOVA test and the significance was set at p < .05. The lowest roughness scores were observed in Z250, Estelite Bulk Fill, and HRi ENA in most of the test groups. Among conventional composites, Z250 group had the highest nanohardness and elasticity modulus scores. Among bulk-fill composites, Estelite Bulk Fill Flow had the lowest surface roughness after immersion in probiotic beverages and the highest nanohardness values. Reveal HD, as a bulk-fill group showed higher surface roughness and considerably lower nanohardness and elasticity modulus scores. Maximum height levels of samples were recorded. SEM images revealed voids and microcracks on the surfaces of test materials. Dentists may prefer Z250 as microhybrid and Estelite Bulk Fill Flow as bulk-fill composites for the restorations of patients who consume gut-friendly drinks regularly. When there are various types of materials, nanoindentation is a useful method for evaluating surface alterations and sensible comparisons.

Effect of dental education on knowledge and clinical behavior of turkish dentists' regarding oral-systemic health of geriatric patientsOral-systemic health of geriatric patients (Running title) / Efeito da educação odontológica no conhecimento e comportamento clínico de dentistas turcos em relação à saúde oral e sistêmica de pacientes geriátricos

Objective: The aim is to evaluate the perspectives of dentists' clinical approaches in terms of their knowledge and education regarding oral-systemic health relation of geriatric patients with a digital survey. Materials and Methods: The demographics, oral-systemic health-related lectures in participants' dentistry education, the level of awareness of the oral-systemic health relationship, and behaviors related to clinical applications were investigated on a digital platform with 49 multiple-choice questions. The results were analyzed with the SPSS 24.0 program. Results: Of a total of 410 dentists (206 women and 204 men), 23% have doctoral and/or specialty titles. While 93.1% of dentists had taken systemic health-related lectures, 21.3% of them rated these courses as "adequate" and 49.3% as weak. 72% of the participants received medical history only at the initial appointment, while 17.9% of them received it at each appointment. Dentists more often associate diabetes and cardiovascular diseases with periodontitis, compared to the development of dental caries. Dentists who think that they should work with physicians in the treatments of geriatric patients with systemic diseases refer more patients to physicians per year (p < 0.001). Conclusions: Dentists have found the lectures on the relationship between oral-systemic health of geriatric patients in dentistry education inadequate. Besides, there is a lack of information on the effects of systemic diseases on caries development, intra-oral findings, and knowledge on treatment approaches. Dentists believe that defining a curriculum that emphasizes interdisciplinary work and organizing scientific activities in partnership with medical associations will play an important role in establishing awareness of oral-systemic health. (AU)

Objetivo: O objetivo é avaliar as perspectivas das abordagens clínicas dos dentistas em relação ao seu conhecimento e educação sobre a relação da saúde oral e sistêmica de pacientes geriátricos através de um questionário digital. Material e Métodos: Os dados demográficos, as aulas relacionadas à saúde oral-sistêmica na educação odontológica dos participantes, o nível de conhecimento da relação saúde oral e sistêmica e os comportamentos relacionados às aplicações clínicas foram investigados em uma plataforma digital com 49 questões de múltipla escolha. Os resultados foram analisados com o programa SPSS 24.0. Resultados: De um total de 410 dentistas (206 mulheres e 204 homens), 23% possuem título de doutor e / ou especialidade. Enquanto 93,1% dos dentistas tiveram aulas sobre saúde sistêmica, 21,3% avaliaram esses cursos como "adequados" e 49,3% como fracos. 72% dos participantes recebem histórico médico apenas na consulta inicial, enquanto 17,9% deles recebem em cada consulta. Os dentistas associam mais frequentemente diabetes e doenças cardiovasculares à periodontite, em comparação ao desenvolvimento de cárie dentária. Os dentistas que acham que devem trabalhar em conjunto com médicos no tratamento de pacientes geriátricos com doenças sistêmicas encaminham mais pacientes ao médico por ano (p <0,001). Conclusões: Os cirurgiões-dentistas consideram inadequadas as palestras sobre a relação entre saúde oral e sistêmica de pacientes geriátricos no ensino de odontologia. Além disso, faltam informações sobre os efeitos das doenças sistêmicas no desenvolvimento de cárie, achados intraorais e conhecimento sobre as abordagens de tratamento. Os dentistas acreditam que a definição de um currículo que enfatize o trabalho interdisciplinar e a organização das atividades científicas em parceria com as associações médicas terá um papel importante no estabelecimento da consciência sobre a saúde oral e sistêmica (AU)

Effect of Light Curing Modes on the Color Stability of a Nanohybrid Composite Immersed in Different Beverages / Efecto de diferentes modos de fotopolimerización en la estabilidad del color de una resina compuesta nanohíbrida inmersa en diferentes bebidas

Abstract: Aim: Sufficient polymerization remains as crucial for composites to prevent discoloration. Both LEDs and halogen units are used for polymerization and different curing modes are improved to overcome inadequate polymerization. This in vitro study investigated staining susceptibility of a nano-hybrid resin composite light-cured in different modes and immersed in different staining media. Methods: Disc-shaped specimens were prepared from nano-hybrid resin composite (Filtek Z550) and light- cured according to following modes: Halojen (GI), LED standard (GII), LED pulse (GIII) or LED ramp (GIV). Half of the specimens of each group (n=7) were stored in one of the staining media (red wine or coffee) for 10 min/day during experimental period. Measurements were performed using spectrophotometer according to CIEL*a*b system at baseline and on 7, 28 and 56 days. Colour differences (∆E) between groups were submitted to statistical analysis. Results: Regarding 7-day evaluation, colour change values of specimens immersed in coffee revealed no remarkable difference among curing modes (p>0.05); whereas specimens in GIV were significantly less stained compared to specimens in GII and GIII when immersed in red wine. Regarding 56- days of evaluation, specimens of GIV showed statistically significant colour change in red wine compared to other groups. However specimens in GI revealed the least staining after 56-days of coffee immersion, and this result was statistically different from LED groups. Conclusion: This study suggest that light-curing mode influences the staining susceptibility of the tested composite. Composites polymerized with halogen unit showed lower staining than all LED modes. Despite novel light sources, halogen units may still used reliably at clinics.

Resumen: Objetivo: La polimerización suficiente sigue siendo crucial para que los compuestos eviten la decoloración. Tanto los LED como las unidades halógenas se utilizan para la polimerización y se mejoran los diferentes modos de curado para superar la polimerización inadecuada. Este estudio in vitro investigó la susceptibilidad a la tinción de un compuesto de resina nano-híbrida curado a la luz en diferentes modos y se sumergió en diferentes medios de tinción. Métodos: Las muestras en forma de disco se prepararon a partir de un compuesto de resina nano-híbrida (Filtek Z550) y se curaron con luz de acuerdo con los siguientes modos: Halojen (GI), estándar de LED (GII), pulso de LED (GIII) o rampa de LED (GIV). La mitad de las muestras de cada grupo (n = 7) se almacenaron en uno de los medios de tinción (vino tinto o café) durante 10 minutos / día durante el período experimental. Las mediciones se realizaron utilizando un espectrofotómetro de acuerdo con el sistema CIEL * a * b en la línea de base y en 7, 28 y 56 días. Las diferencias de color (∆E) entre los grupos se sometieron a análisis estadístico. Resultados: Con respecto a la evaluación de 7 días, los valores de cambio de color de las muestras sumergidas en café no revelaron diferencias notables entre los modos de curado (p> 0.05); mientras que las muestras en GIV se tiñeron significativamente menos en comparación con las muestras en GII y GIII cuando se sumergieron en vino tinto. Con respecto a los 56 días de evaluación, las muestras de GIV mostraron un cambio de color estadísticamente significativo en el vino tinto en comparación con otros grupos. Sin embargo, las muestras en GI revelaron la menor tinción después de 56 días de inmersión en el café, y este resultado fue estadísticamente diferente de los grupos LED. Conclusión: este estudio sugiere que el modo de fotopolimerización influye en la susceptibilidad de tinción del material compuesto probado. Los compuestos polimerizados con una unidad halógena mostraron una tinción más baja que todos los modos LED. A pesar de las nuevas fuentes de luz, las unidades halógenas todavía pueden usarse de manera confiable en las clínicas.

Effect of black tea and matrix metalloproteinase inhibitors on eroded dentin in situ.

Purpose of this in situ study was to evaluate the surface properties of eroded dentin specimens activated with three different matrix metalloproteinase (MMP) inhibitors (chlorhexidine [CHX], fluoride, green tea), black tea, and water. One hundred eighty dentin samples were prepared from extracted third molars and then samples divided into six groups. Ten volunteers were carried three specimens of each group, on acrylic palatal appliances, which were fabricated exactly for them (n = 3). Erosive cycles were done by immersing appliances in cup containing Cola and was followed by rinsing with test solutions. Microhardness values were measured. Surface properties were investigated by atomic force microscopy (AFM). Lowest change in microhardness was shown in fluoride group whereas negative control group (water) had the highest change. There were no statistically significant differences among surface roughness changes (p > .05). The least change in microhardness was seen in the fluoride group (13.05 ± 8.07), while the control group showed the highest change (33.80 ± 12.42) and was statistically significant when compared to other groups (p < .05). Besides lowest depth, values were shown in fluoride group as well. AFM evaluations showed macromolecular deposits on surfaces of fluoride, CHX, and black tea groups. No superior results were detected in CHX + fluoride group and black tea showed similar surface characteristics as green tea. Mouthrinses containing not only green tea but also black tea could be beneficial for patients with exposed dentin surfaces. Catechines and theaflavins in teas could be useful for improving surface quality.