Comparative Clinical Study of Two Tooth Whitening Protocols.

This study aimed to clinically evaluate the effectiveness of two different at-home whitening protocols and to determine which is more effective: applying the whitening gel (16% carbamide peroxide) every 24 hours (Group A) or every 48 hours (Group B) for 2 weeks. Group C received a placebo gel (glycerin) without peroxide, which was applied every 24 hours for 2 weeks. The differences in terms of tooth sensitivity were also analyzed. A sample of 60 patients was divided into three groups of 20 patients. To compare the groups, color measurements were made using a spectrophotometer, and Student t test was used for independent samples. The confidence level was set at 95% (P ≤ .05). No statistically significant differences were found between Groups A and B (P > .05). The study concluded that 16% carbamide peroxide was equally effective when applied with either protocol and obtained the same results, but the 48-hour application protocol produced less sensitivity than the 24-hour application protocol.

Simulation of Liquids with the Tight-Binding Density-Functional Approach and Improved Atomic Charges.

Theoretical description of liquids, especially liquid water, is an ongoing subject with important implications in various domains such as homogeneous catalysis; solvation of molecular, ionic, and biomolecular species; and reactivity. Various formalisms exist to describe liquids, each one displaying its own balance between accuracy and computational cost that defines its range of applications. The present article revisits the ability of the density-functional-based tight-binding (SCC-DFTB) approach to model liquids by focusing on liquid water and liquid benzene under ambient conditions. To do so, we benchmark a recent correction for the SCC-DFTB atomic charges that allows for a drastic improvement of the pair radial distribution functions of liquid water as compared to both experimental data and density-functional theory results performed in the generalized-gradient approximation. We also report the coupling of the deMonNano and i-PI codes to perform path-integral molecular dynamics. This allows us to rationalize the impact of nuclear quantum effects on the SCC-DFTB description of liquid water. This study evidences the rather good ability of SCC-DFTB to describe liquid water and liquid benzene. As the first example of application, we also present results for a benzene molecule solvated in water with the perspectives of further studies devoted to solvent/water interfaces.

Changes in plaque and gingivitis levels after tooth bleaching: A systematic review.

OBJECTIVES: The primary aim of this systematic review was to evaluate the effect of external tooth-bleaching products on plaque indices and to compare it to a placebo or a negative control. METHODS: A protocol was developed aimed to answer the next focused question: What is the effect of tooth bleaching compared to no treatment or a placebo, in subjects without periodontitis aged ≥18 years in the levels of plaque and gingivitis? Two electronic databases were used as sources in the search for studies satisfying the inclusion criteria: (a) The National Library of Medicine (MEDLINE via PubMed); (b) Cochrane Central Register of Controlled Trials. RESULTS: Only randomized controlled trials were included. The initial search found 382 potential publications. Seven of them were finally included, and six were used in the meta-analyses. The use of bleaching products showed higher reductions in plaque (n = 6; standardized mean difference [SMD] = 0.47; 95% confidence interval [CI] = 0.06, 0.88; P < 0.001) and gingivitis indices (n = 4; SMD = 0.47; 95% CI = 0.22, 0.73; P < 0.001), when compared to a control group (no treatment or placebo). CONCLUSIONS: External tooth bleaching is associated with statistically significant short-term reductions in plaque and gingivitis indices. However, no data were available to evaluate long-term effects.

Impression technique for a complete-arch prosthesis with multiple implants using additive manufacturing technologies.

This article describes an impression technique for a complete-arch prosthesis supported by multiple implants where additive manufacturing technologies were used to fabricate a splinting framework and a custom tray. The technique presented uses a shim method to control the homogenous splinting acrylic resin and impression material during the procedure, thereby reducing laboratory and chairside time and the number of impression copings and laboratory analogs needed.

Clinical efficacy of a bleaching system based on hydrogen peroxide with or without light activation.

The objective of the present study was to assess the clinical efficacy of a dental bleaching system based on hydrogen peroxide with or without light activation. This randomized controlled trial evaluated the effect of the light when applied to the hydrogen peroxide by using a split-mouth design with 21 patients, with light activation in one hemi-arch but not in the other. The bleaching agent was QuickWhite 35% hydrogen peroxide and activation was conducted with a diode lamp (Luma Cool). The Classic Vita Guide was used to score tooth shades. Two consecutive applications of hydrogen peroxide were made to one hemi-arch, each light-activated for 10 min. The other hemi-arch was then identically treated but without light activation. After removal of the bleaching agent, the shade was re-scored and the Wilcoxon signed ranks test was used to compare differences in tooth shade values. The bleaching treatment produced significant shade changes (P < 0.01) in both hemi-arches. After treatment, there were no statistically significant differences between light-treated and non-light-treated tooth types (central incisors, lateral incisors, and canines). However, taking central incisor, lateral incisor, and canine as a group, comparison between each hemi-arch showed a significant effect in the hemi-arch with light activation (P < 0.05). The use of diode light with a 35% hydrogen peroxide gel slightly improved the dental bleaching.

Comparative clinical study of two tooth bleaching protocols with 6% hydrogen peroxide.

Objective. The objective was to compare the clinical efficacy of two different tooth bleaching protocols after 1 and 2 weeks of treatment with an over-the-counter paint-on gel containing 6% hydrogen peroxide. Material and methods. Sixteen volunteer patients (minimum shade A2 or darker on maxillary teeth) were selected to participate in this randomized, single-blind (examiner-blinded), single-center, 2-group clinical trial using a divided mouth model. The product was applied in our clinic to one hemi-arch (Group I) in each patient at two sessions one week apart, making five applications at each session (separated by 10 min intervals). The patients themselves applied the product once a day for 10 days in the other hemiarch (Group II). Efficacy was measured according to the Vita Classical shade guide at baseline and at one and two weeks. Differences between groups (office-treated vs. home-treated hemiarches) were tested by repeated-measures analysis of variance. Results. Significant (P < .05) differences in shade values were detected between pre- and post-bleaching in both groups. The two groups did not significantly differ in tooth shade at the end of the treatment. Conclusions. Treatment with 6% hydrogen peroxide gel using the paint-on system shows significant clinical efficacy whether applied by clinicians or by the patients themselves.

La espiral de Gibson y el aprendizaje psicomotriz en odontología / No disponible

El Test de la Espiral de Gibson mide habilidades psicomotrices. Se usa en medicina y cirugía, en diferentes especialidades y en empresas (AU)

The Gibson Spiral Maze Test measure psychomotor skills. The test use in Medicine and surgery, in different medical specialities and industries (AU)

Aprendizaje y adquisición de habilidades en materiales odontológicos: manejo de escayola piedra mejorada / No disponible

La escayola tipo IV, es un material muy usado por los estudiantes de odontología en la realización de las prácticas preclínicas. En el presente estudio evaluamos el aprendizaje de las habilidades psicomotrices de los estudiantes, cuando realizan una figura geométrica con escayola dental (AU)

Dental Stone type IV, is a dental material used very often by dental students in preclinic practices. In the present study we evaluate the students learning skills, when making geometrical form made of dental Stone (AU)

Estudio y comparación de discos para terminación y pulido de superficies / No disponible

Es muy necesario para tener una buena terminación, pulir los materiales odontológicos. El pulido se puede realizar con discos. Nosotros estudiamos y comparamos tres marcas de discos (AU)

Is very necessary for obtain a good completion to polish the dental materials. The polish we can make with disk. We study and comparison tree disk mark (AU)

Aprovechamiento de raíces en pacientes ancianos con postes de fi bra de vidrio. Una solución de baja agresividad. A propósito de algunas experiencias clínicas / No disponible

Se realiza una revisión de las posibilidades de aprovechamiento de restos radiculares en pacientes ancianos, y basados en experiencias clínicas, se propone la utilización de postes de fibra de vidrio reforzados con composites (FRC) como una alternativa de primera elección (AU)

Revision of the possibilities of making good use of root rest in elderly patients based in clinical experiences, we suggest the usefulness of glass fibre post strengthened with dental composite as an alternative of first choice (AU)