To explore the vitamin D levels of periodontitis patients in comparison with periodontally healthy ones, and to assess the influence of vitamin D supplementation as an adjunctive during nonsurgical periodontal treatment (NSPT). Five databases (Pubmed, Embase, Scholar, Web of Sciences, and Cochrane Library) were searched until May 2020. Mean difference (MD) meta-analysis with corresponding 95% confidence interval (95% CI) and sensitivity tests via meta-regression were used. We followed Strength of Recommendation Taxonomy (SORT) to appraise the strength and quality of the evidence. Sixteen articles were included, fourteen case-control and two intervention studies, all reporting 25-hydroxyvitamin D (25(OH)D) levels. Compared with the healthy controls, the circulating 25(OH)D levels were significantly lower in chronic periodontitis patients (pooled MD = −6.80, 95% CI: −10.59 to −3.02). Subgroup analysis revealed differences among 25(OH)D measurements, with liquid chromatography-mass spectrometry being the most homogeneous method (pooled MD = −2.05, 95% CI: −3.40 to −0.71). Salivary levels of 25(OH)D showed no differences between groups. Due to the low number of studies, conclusions on aggressive periodontitis and in the effect of vitamin D supplementation after NSPT were not possible to ascribe. Compared with healthy controls, 25(OH)D serum levels are significantly lower in chronic periodontitis patients, with an overall SORT A recommendation. Future studies are needed to clarify the effect of vitamin D supplementation and the biological mechanisms linking vitamin D to the periodontium.

Prediction of accurate dielectric property data from fundamental principles for systems as complex as foods has not been possible. Simple prediction models based on easily measurable composition data can serve many useful purposes. Literature dielectric data on foods and their composition were statistically correlated. Dielectric data on salt solutions were measured to explain some of the results. When composition data were not available, standard handbook compositions were used. Inclusion of all types of foods (meats, fruits, and vegetables) inhibited any useful correlation with composition. Based on a smaller data set of meats, both dielectric constant and loss increased with water and salt content. Dielectric constant generally decreased with temperature whereas dielectric loss decreased with temperature at lower salt concentrations and increased with temperature at higher salt concentrations.

The aim was to evaluate the effect of different antioxidant agents on the improvement of bond strength to enamel subjected to a whitening procedure. Samples were divided into six groups (n = 10): control; whitening immediately followed by restorative treatment (WHT); whitening and restoration after a 7-day period (WHT_7D); whitening and application of 10% sodium ascorbate (WHT_SA); application of 5% grape seed extract (WHT_GS); and application of 5% green tea (WHT_GT). All groups except for control fwere whitened (Opalescence PF Regular 16%) for 7 days (4 h/day). All samples were restored (Optibond™ FL, Kerr and Filtek™ Z250 composite, 3M ESPE). In antioxidant groups these were applied for 15 min and immediately restored. Specimens were sectioned in microspecimens (1.0 ± 0.2 mm2 area) for microtensile bond strength (μTBS) testing (0.5 mm/min) on a universal testing machine. ANOVA test with Brown-Forsythe correction and Games-Howell post-hoc test was used (significance level of 5%). Antioxidant groups presented significant higher mean μTBS values than group WHT (p < 0.001). The non-whitened control group was not significantly different to antioxidant experimental groups. Group WHT_7D exhibited a significantly higher mean μTBS value when compared to group WHT (p = 0.022). The different antioxidants significantly influenced microtensile bond strength of restored teeth after whitening.

Direct bonding energy relates to the well-known “strength” or “toughness” of wafer direct bonding interface. It is the energy needed to separate two bonded surfaces. In contrast, adhesion energy is the energy available to bring the two surfaces together. Due to hysteretic effects, the two energies may be different and, while the first energy has been largely measured, the second one is the subject of very few papers. In this study, a new phenomenon will be shown in adhesion energy behavior using two silicon wafers. Several partial debondings and rebondings of the same silicon direct bonding structure result in an increase of the bonding wave speed and consequently of the adhesion energy. Using an electrostatic field, it will be shown that this behavior is linked to the electrical states of the bonding interface. This phenomena is not well understood, although it sheds new light on the adhesion mechanism.

A recent restoration of the Basilica Cathedral in Casco Viejo, Panamá, revealed that prior to 1871-1876 female orchid bees (Eufriesea surinamensis) built large nesting aggregations high above the main altar, based on physical evidence dating to a nineteenth-century restoration. Bees constructed cells in approximately 120 clusters in six different aggregations on the reredos ("altarpiece"). Palynological analyses of cell contents showed that bees visited 48 species of plants, representing 43 genera and 23 families. Contents of bee cells reflect elements of floristic diversity surrounding Panama City that are seen in historical contemporaneous photographs of the nesting site and environs. 66Resumen Una restauración reciente de la Catedral Basílica en el Casco Viejo de la ciudad de Panamá reveló que las hembras de abejas solitarias (Eufriesea surinamensis) nidificaron en lo alto de su retablo mayor previo a 1871-1876, basada en evidencia física de una restauración del siglo XIX. Las abejas construyeron celdas en aproximadamente 120 grupos de seis agregaciones diferentes en este retablo. Un análisis de los granos de polen dentro de estos nidos demostró que las abejas visitaron 48 especies de plantas que representan 43 géneros y 23 familias. Los elementos de la diversidad florística en la ciudad de Panamá se pueden observar en fotografías históricas de esta época del sitio de anidación y sus alrededores.