This study compared the ultrastructure, chemical composition, and proteases activity (PA) of sound (SD) and caries-affected dentin (CAD) in the dentin hybrid layer after using an experimental bonding system containing pyromellitic dianhydride glycerol methacrylate and biomimetic analogs. The bonding system used a three step and a total-etch procedure. Polyacrylic acid (5%) and sodium trimetaphosphate (5%) were added to the primer and monocalcium phosphate monohydrate (9%), beta-tricalcium phosphate (10.5%), and calcium hydroxide (0.5%) were added to the adhesive. Transmission electron microscopy (TEM) was used to evaluate the resultant structure, particularly the adhesive-dentin and the demineralized-SD interfaces. The chemical composition was evaluated through energy-dispersive X-ray spectroscopy (EDS) and selected area electron diffraction (SAED). The PA was measured with the Coomassie Blue-G250 coloring test, and the PA data were analyzed by ANOVA. EDS identified the presence of isolated calcium phosphate nanoparticles in the demineralized region; however, the SAED analysis did not show any evidences of hydroxyapatite (HA) neoformation in SD and CAD. The biomimetic analog-based adhesive system inhibited the activities of dentin proteases immediately after treatment. Additionally, the proteolytic activity on the affected dentin resembled that of the SD. In conclusion, no HA formed in the demineralized SD and CAD although there were calcium and phosphate deposits. The experimental adhesive system inhibited dentin proteases. • The present study uses a new approach to investigate the hybrid layer behavior in dentin. • The experimental adhesive system was synthesized and used on sound and affected-caries dentin as the substrate to reproduce real clinical conditions.

O objetivo desta pesquisa foi sintetizar e caracterizar compósitos restauradores experimentais (CRE) com partículas de ionômero de vidro-cálcio pré-reagidas (PRG-Ca). As PRG-Ca foram obtidas a partir da síntese de um vidro de cálcio fluoraluminosilicato e sua reação com ácido poliacrílico. As PRG-Ca foram silanizadas e CRE foram produzidos: E0, E1, E2, E3, E4, E5 e E6. A matriz orgânica (40% p/p) foi composta de Bis-GMA / TEGDMA e canforoquinona / etil N,N-dimetil-4aminobenzoato. O compósito base (E0) continha 60% p/p de partículas de bário-boro-silicato (BaBSi), sendo o controle. Em E1, E2, E3, E4, E5 e E6, o BaBSi foi parcialmente substituído por 10, 20, 30, 40, 50 e 60% p/p de PRG-Ca, respectivamente. O Empress Direct (ED) foi a referência comercial utilizada. Foram avaliadas as seguintes propriedades: grau de conversão (GC), rugosidade (Ra), dureza Knoop (DK), resistência à flexão (RF), módulo de flexão (MF), absorção (Ab), solubilidade (Sl), brilho (GU), translucidez (PT), cor (OE) e o potencial remineralizante (PR) através de microtomografia. Os dados foram submetidos à análise de variância e teste de Tukey HSD (a 0,05). Quanto à Ra, DK e GU, não houve diferença entre os CRE. O aumento de PRG-Ca diminuiu GC, RF, MF e PT e aumentou Ab, Sl, OE e PR. Na maioria das propriedades avaliadas, ED apresentou comportamento intermediário aos CRE. E0 e ED não apresentaram PR. Os CRE com PRG-Ca demonstraram ser materiais bioativos promissores, apresentando bom desempenho nas propriedades avaliadas e um potencial remineralizante que aumenta com uma maior concentração de PRG-Ca.Palavras-chave: Resinas Compostas. Remineralização Dentária. Propriedades Físicas e Químicas.

Foramen of Huschke (FH) is a normal anatomical structure performed until the total maturation of the cranium skeleton, which obliterates by a natural process about the 5-yearold. However, it may persist in adult life and can be rarely associated with complications in the temporomandibular joint (TMJ) and external auditory canal apparatus as well as a higher risk of tympanic injury during surgical procedures such as TMJ arthroscopy. The aim of this study was to report the prevalence and morphometric features of persistent FH in a Brazilian adult temporal bones sample. The methods included an anatomic and morphometric analysis of 146 dried temporal bones obtained from adult cadavers.Twenty-two (15.0%) of the temporal bones presented persistent FH. Unilateral FH accounted for 4 (30.8%) and bilateral foramens for 18 (69.2%) of the 13 affected craniums.Forms varied, including 2 (7.8%) circular, 12 (46.1%) oval and 12 (46.1%) irregular FH.Ten (45.4%) of the temporal bones presenting FH were observed in the right side and 12 (54.6%) in the left. Mean size of FH was 3,00 mm in the transversal and 2,52 mm in the longitudinal axis. Additionally, the mean anterior and posterior distances from two adjacent anatomical structures, petrotympanic fissure, and styloid process were 4,23 mm and 9,9 mm respectively. In conclusion, there seemed to be a considerable morphological heterogeneity when comparing the persistent FH specimens. We, additionally, highlight the importance of clinicians and oral and maxillofacial surgeons know this condition and its anatomical implications.