The aim of this study were characterize acellular collagen matrices derived from porcine pericardium (PP) and to evaluate their properties after sterilization by ethylene oxide and gamma ray. PP matrices were subjected to alkaline hydrolysis (AH), and samples were characterized for biological stability, membrane thickness measurements, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Subsequently, the matrices were frozen, lyophilized and sterilized by ethylene oxide or gamma radiation. For in vitro assays, CHO-K1 cell culture was used and evaluated for cytotoxicity, clonogenic survival assay, genotoxicity and mutagenicity. Analysis of variance (ANOVA) was used, followed by Dunnett’s post-test, with a significance level of 5%. After AH, there was no significant change in matrix thickness. The relative biodegradability of the material after implantation was observed. Morphology and dimensions had small changes after AH. As for cell viability, none of the tested matrices showed a statistically significant difference (p > 0.05; Dunnett) regardless of the sterilization method. Furthermore, it was found that PP matrices did not interfere with the proliferation capacity of CHO-K1 cells (p > 0.05; Dunnett). As for genotoxicity, when sterilized with ethylene oxide (NP, P12 and P24), it showed genotoxic potential, but it was not genotoxic when sterilized by gamma radiation. No mutagenic effects were observed in either group. PP-derived collagen matrices hydrolyzed at different times were not cytotoxic. It is concluded that the best method of sterilization is through gamma radiation, since no significant changes were observed in the properties of the PP matrices.

Objectives: The reconstruction of endodontically treated teeth with significant coronal destruction often requires the use of posts. This study evaluated the bond strength of four intraradicular post systems in different root regions using a push-out test: conventional fiberglass, CAD/CAM fiberglass, Splendor SAP, and anatomical posts. Materials and Methods: Nineteen single-rooted premolars were treated endodontically and divided into four groups. The posts were cemented with dual self-adhesive resin cement and then sectioned into 1 mm slices for push-out testing. Results: The cervical region had a higher bond strength than middle and apical thirds. Conventional fiberglass posts presented higher resistance than anatomical posts (p=0.048). Conclusions: These results confirm that cervical thirds present the best bonding conditions and that conventional fiberglass posts outperform the anatomical ones.

Despite the numerous books on dental anatomy, there are few scientific articles that cover a detailed study of the external morphology of teeth. The development of studies aimed at the morphological evaluation of upper premolars, mainly for differentiation between them, is quite relevant for the Discipline of Dental Anatomy, and, consequently, for Dentistry. The objective of this study was to analyze the morphology of upper premolars, highlighting the differences between them. Measurements were performed using a digital caliper, along with the visual analysis of some anatomical structures 100 first premolars (UFPM) and 100 second premolars (USPM) from a teaching collection. Since the data presented normal distribution, t-test and Chi-square test were performed. The results of this study demonstrate that UFPM and USPM exhibit measurements and features that facilitate their identification and differentiation. Some anatomical aspects are more frequent and uniform, while others show greater variability. It was concluded that the root is not a significant characteristic for distinguishing between them, as the majority of UFPM and USPM in our sample presented one root. The larger buccal cusp and the presence of a cervical depression on the mesial surface of UFPM, a short central groove and more frequent supplemental grooves in USPM, are important features for differentiating between upper premolars. For assisting in the identification of the side of extracted teeth, the lingual cusp mesially deviated is a frequent characteristic for both upper premolars. Understanding these characteristics favors the identification of teeth in Dental Anatomy classes.