Anterior Upper Teeth Golden Proportion Analysis with Millimetric Templates: An Invention Developed at Londrina State University.

In order to achieve aesthetic and harmonious smile results, the use of anterior upper teeth golden proportion concepts represents reliable and scientific based guidelines. However, measuring, recording and analysing teeth and smiles biometric values proves to be a clinical and laboratory routine chalenge, once it is time consuming and demands additional especific math calculus or formulas. The aim of this paper is present an invention, "anterior upper teeth golden proportion millimetric templates," a set of instruments fabricated in order to achieve precise and fast millimetric measures, once they present predefined geometrical drawings and diagrams. Currently, when planning aesthetic tooth size modifications treatments, tools are used as pachymeters, dry edge compass, or some softwares. Most of times this strategy relies on professional expertise and intuiton, which shows to be limitating factors with the need of trial-and-error training and an accurate critical and artistic sense. Unfortunately, this is not inherent to all professionals, especially undergraduate dental school students. Thus, the templates bring differentials and advantages, being versatile and convenient, allowing countless clinical and laboratory uses, even over a cellphone or a computer screen. An excellent diagnostic aid providing ideal teeth proportions and positioning, increasing the chances of success in dental treatment planning.

Prótese adesiva em resina composta reforçada por fibras para dentes posteriores / Fiber-reinforced composite fixed partial denture in posterior teeth

Próteses parciais fixas de resina reforçadas por fibras (PPFRF) têm sido aperfeiçoadas ao longo dos anos para a substituição de dentes ausentes como uma alternativa às próteses convencionais com infra-estrutura metálica. Este relato de caso descreve os procedimentos clínicos e laboratoriais para a fabricação de uma PPFRF para a reposição de um dente posterior ausente com fibras de vidro pré-impregnadas (Vectris, Ivoclar Vivadent Inc., Schaan, Liechtenstein) em meio a uma matriz resinosa (SR Adoro, Ivoclar Vivadent Inc., Schaan, Liechtenstein). Após 48 meses de observação, não houve sinais de descoloração, perda de textura superficial ou micro-infiltração, mesmo considerando que a paciente era fumante.

Fiber-reinforced composite fixed partial dentures (FRCFPDj have been improved to be used a single tooth replacement being an alternative to the conventional metal based fixed partial dentures. This case report describes clinical and laboratorial FRCFPD confection procedures using a pre-impregnated 9 lass fibers (Vectris, Ivoclar Vivadent Inc., Schaan, Liechtenstein) embebed in a resin matrix (SR Adoro, Ivoclar Vivadent Inc., Schaan, Liechtenstein) to replace a missing posterior teeth. After 48 months of observation no signs of discoloration, lost of surface texture or microleakage, even considering that the patient was smoker, were observed.

In vitro assessment of solvent evaporation from commercial adhesive systems compared to experimental systems.

Solvents should be properly evaporated after application to dental substrates. The aim of this study was to assess the evaporation of commercial, experimental and neat solvents. The tested null hypotheses were that there are no differences in solvent evaporation regardless of its formulation and over time. Evaporation from commercial adhesive systems (Scotchbond Multipurpose Primer, Scotchbond Multipurpose Adhesive, Prime & Bond NT, Multi Bond, Excite, Single Bond 2, Adhese Primer, Adhese Bond, Xeno III A and Xeno III B) and experimental primers (35% HEMA plus 65% acetone or ethanol or water v/v) were compared to neat solvents (acetone, ethanol and water). Samples (10 microL) of these products were dripped into glass containers placed on a digital precision balance. Evaporation was assessed at 0, 5, 10, 15, 30, 60, 120, 300 and 600 s times to calculate mass loss. Data were analyzed statistically by ANOVA and Bonferroni's correction (a=0.05). Acetone-based products exhibited a remarkable capacity to evaporate spontaneously over time. Neat acetone evaporated significantly more than the HEMA-mixtures and the commercial formulations (p<0.05). The incorporation of monomers and other ingredients in the commercial formulations seem to reduce the evaporation capacity. Solvent evaporation was time and material-dependent.

In vitro assessment of solvent evaporation from commercial adhesive systems compared to experimental systems

Solvents should be properly evaporated after application to dental substrates. The aim of this study was to assess the evaporation of commercial, experimental and neat solvents. The tested null hypotheses were that there are no differences in solvent evaporation regardless of its formulation and over time. Evaporation from commercial adhesive systems (Scotchbond Multipurpose Primer, Scotchbond Multipurpose Adhesive, Prime & Bond NT, Multi Bond, Excite, Single Bond 2, Adhese Primer, Adhese Bond, Xeno III A and Xeno III B) and experimental primers (35 percent HEMA plus 65 percent acetone or ethanol or water v/v) were compared to neat solvents (acetone, ethanol and water). Samples (10 µL) of these products were dripped into glass containers placed on a digital precision balance. Evaporation was assessed at 0, 5, 10, 15, 30, 60, 120, 300 and 600 s times to calculate mass loss. Data were analyzed statistically by ANOVA and Bonferroni's correction (a=0.05). Acetone-based products exhibited a remarkable capacity to evaporate spontaneously over time. Neat acetone evaporated significantly more than the HEMA-mixtures and the commercial formulations (p<0.05). The incorporation of monomers and other ingredients in the commercial formulations seem to reduce the evaporation capacity. Solvent evaporation was time and material-dependent.

O solvente deve ser adequadamente evaporado após aplicação ao substratos dentários. O objetivo deste estudo foi avaliar a evaporação de formulações comerciais, primers experimentais e solventes puros. As hipóteses nulas testadas foram de que não há diferenças da quantidade evaporada independentemente do material e tempo. Evaporação dos sistemas adesivos comerciais (Scotchbond multipurpose primer, Scotchbond multipurpose adhesive, Prime & Bond NT, Multi Bond, Excite, Single Bond 2, Adhese Primer, Adhese Bond, Xeno III A e Xeno III B) e primers experimentais (35 por cento HEMA associado com 65 por cento acetona, etanol ou água v/v) foram comparadas a solventes puros (acetona, etanol e água). Amostras (10 µL) de cada produto foram dispensadas em balança de precisão digital. As massas nos tempos 0, 5, 10, 15, 30, 60, 120, 300 e 600 s foram registradas. Os dados foram analisados estatisticamente por ANOVA e Bonferroni (a=0,05). Produtos a base de acetona exibiram maior capacidade de evaporação espontânea ao longo do tempo. Acetona pura evaporou significantemente mais que as misturas de HEMA e formulações comerciais (p<0,05). A incorporação de monômeros e outros ingredientes nas formulações comerciais reduzem a capacidade de evaporação. A evaporação é dependente do produto e do tempo.

Water sorption and solubility of dentin bonding agents light-cured with different light sources.

OBJECTIVE: The aim of this study was to compare water sorption (WS) and solubility (WSB) of different dentin bonding agents (DBA) as regards classification and light-activation system. The null hypotheses were: (1) there is no difference among DBA with respect to water sorption and solubility; (2) there is no effect of light-curing source on water sorption and solubility of DBA. METHODS: The tested materials were: three-step etch-and-rinse (ScotchBond multi-purpose and Heliobond-control groups), two-step etch-and-rinse (Excite, Adper Single Bond, Adper Single Bond 2), self-etching (Adhse) and all-in-one (Xeno III) systems. For each material, six specimens were prepared (0.8mmx5.5mm) for each light-activation device: halogen lamp (control) or light-emitting diodes (LED). They were transferred to desiccators until a constant mass was obtained (m(1)), subsequently immersed in deionized water until no alteration was obtained (m(2)). Following, the specimens were reconditioned to constant mass in desiccators (m(3)). The volume (V) of each specimen was calculated (mm(3)). WS and WSB were determined using the equations (m(2)-m(3)/V) and (m(3)-m(1)/V), respectively. Data were subjected to one-way analysis of variance and Tukey test (p<0.05). The influence of photo-activation units was analyzed by t-test. RESULTS: Higher values of WS and WSB were observed for the two-step etch-and-rinse and all-in-one systems. The employed light-activation unit also affected the tested characteristics. Thus, the anticipated null hypotheses were rejected. CONCLUSIONS: Simplified systems were more susceptible to water adverse and they may become more prone to degradation over time regardless of the type of light-activation source.