Ana Portela

Background: This systematic review aimed to evaluate the effect of dentin pretreatment strategies on bond strength to natural caries-affected dentin (NCAD) in permanent human teeth. Methods: A systematic search was conducted in PubMed, Web of Science, and Scopus databases up to April 2026, following PRISMA guidelines. Experimental and quasi-experimental in vitro studies evaluating the bond strength of resin restorations to NCAD after the application of dentin pretreatment strategies prior to adhesive procedures were included. Studies involving modified adhesive systems, artificial caries-affected dentin, or primary teeth were excluded. Risk of bias was assessed using the QUIN tool. Due to methodological heterogeneity, a qualitative synthesis was performed. Results: A total of 1071 studies were identified, of which 9 met the inclusion criteria. Pretreatment strategies were categorized into cross-linking/biomodulation, remineralization, and fluoride-based approaches. Cross-linking strategies, particularly flavonoid-based agents, consistently improved bond strength. Remineralization approaches, including CPP-ACP, demonstrated condition-dependent effects, particularly under aging conditions. Fluoride-based strategies showed more variable outcomes. Most included studies presented moderate risk of bias. Conclusions: Cross-linking/biomodulation strategies demonstrated the most favourable bond strength outcomes to NCAD, while remineralization approaches showed potential benefits under aging conditions. However, the available evidence remains limited and methodologically heterogeneous, indicating the need for further standardized studies.

Azevedo MJ, et al. J Adv Prosthodont. 2019 Jun;11(3):155-161. https://doi.org/10.4047/jap.2019.11.3.155

Objetivos: Pretendeu- se detetar e quantificar a concentração dos metais pesados presentes no osso de choco, antes e depois de ser submetido a um processame...

Tiago Escobar, DDS, MS/Jo?o Almeida e Sousa, DDS, MS/Ana Portela, DDS, PhD/ M?rio Vasconcelos, DDS, PhD/Ricardo Faria de Almeida, DDS, MS, PhD: Purpose: The primary objective of this pilot study was to evaluate the effectiveness of biphasic calcium phosphate (BCP) covered with a polyethylene glycol (PEG) membrane in the regeneration of 5-mm-diameter defects created in the calvaria of Wistar rats and compare this with the regeneration of defects covered only with the PEG membrane. Materials and Methods: Two 5-mm-diameter parietal defects were created in seven Wistar rats. The control defect in the left parietal bone was covered with an experimental PEG membrane (Straumann MembraGel); the test defect in the right parietal bone was filled with BCP (Straumann BoneCeramic) and covered with the same membrane. After a healing period of 2 months, the animals were sacrificed, and the samples were processed for histologic and histomorphometric analysis. Results: The test defects regenerated with BCP and covered with the PEG membrane had a percentage of new bone formation area of 61.7% ? 14.6%, and the control defects obtained mean new bone area of 57.3% ? 21.8%. The difference between groups was not statistically significant. The BCP did not reveal osteoconductive properties, and few particles were fully incorporated into the newly formed bone. The BCP maintained the space, and there was extremely low particle resorption during the healing period. The PEG membrane remained intact. Conclusion: There were no statistically significant differences between the test and control groups. BCP did not exhibit osteoconductive properties.

Purpose: Evaluation of the effectiveness of highly focalised thermotherapy (HFT) in a melanoma mouse model, using a ferrimagnetic cement (FC) and repeated low hyperthermia treatments. Materials and methods: A melanoma mouse model was induced with B16F10 cells in C57BL6 mice. The FC, injected into the tumour, was used as the magnetic vehicle for HFT. FC location within the tumour was assessed by radiography and its capability to generate heat, when exposed to an external high frequency magnetic field (HFMF), monitored by thermal camera. The HFT treatment consisted of three HFMF exposures, with 48-h intervals, each one lasting 30 min, with a 5–6°C tumour temperature increase. At the end of the experiment, FC samples were characterised by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). The presence of iron contents was analysed in the tumour, lungs, liver and spleen. Histological evaluation and immunohistochemical staining for caspase-3 were performed. Tumour growth was monitored during the experiment. Results: Surface analysis showed FC stabilisation within the tumour, and iron was absent. The thermal camera confirmed the localised temperature increase in the tumour. HFT treatments inhibited the tumour growth by ∼70% compared to controls. This was due to cell destruction by necrosis and apoptosis. Conclusions: The HFT, using the FC, proved to be a minimally invasive technique that statistically inhibited tumour growth. Results suggested that this methodology seems to be a promising technique for the treatment of solid tumours, allowing repeated low hyperthermia treatments, which can be easier and less traumatic than other hyperthermia techniques.

The cancer treatment by local hyperthermia, using a high frequency electromagnetic field is an extensively studied subject. For this propose it was developed a ferrimagnetic cement (FC) to be injected directly into the tumor. In this study it was determined the FC injectability, its capability to generate heat when placed within a magnetic field and its interaction with a modified simulated body fluid using SEM/EDS and XRD. The FC biological response was assessed by the intramuscular implantation in rats and histological analysis of the surrounding tissues. The results suggest that FC can be injected directly into the tumor, its temperature can be increased when exposed to a magnetic field and the surface of the immersed samples quickly becomes coated with precipitate denoting its ionic change with the surrounding medium. The histological analysis revealed a transient local inflammatory reaction, similar to the control material, only slightly more abundant during the first weeks, with a gradual decrease over the implantation time. Based on these results, we concluded that FC might be useful for highly focalized thermotherapy, with a good potential for clinical use.

ObjectivesEvaluation of the polymerization shrinkage and depth of cure of two composite resins, with different organic matrix.MethodsTwo composite resins were used in this study, the Filtek™Silorane with a silorane resin matrix and the Filtek™P60 with a methacrylate resin matrix. The polymerization shrinkage was determined through the measurement of the density in accordance with the Archimedes principle and the statistical evaluation with the “t student” parametric test to the difference of the expected values (p>0,05). The depth of cure was calculated through the micrometric measurement of the samples, according to the standard ISO4049:2000 (E). In both studies there were used the light curing units LED (Light Emitting Diodes) and QTH (Quartz Tungsten Halogen).ResultsIt was verified a statistical evidence of which the resin composite Filtek™Silorane reaches values of polymerization shrinkage inferiors [1,14% (QTH) and 1,18% (LED)] being also the values of depth of cure inferior [(1,74mm (QTH) and 1,99mm (LED)], comparatively with the composite resin FiltekTMP60 [2,33% (QTH) and 2,42% (LED)] and [2,45mm (QTH) and 2,85mm (LED)].ConclusionsThe properties of polymerization shrinkage and depth of cure are dependent variables of factors like the type of resin matrix, the content and type of filler and the light curing unit used. The composite resin Filtek™Silorane reported lower polymerization shrinkage and depth of cure compared with the composite resin Filtek™P60.ResumoObjectivosAvaliação da contracção e profundidade de polimerização de duas resinas compostas, com diferente matriz orgânica.MétodosNeste estudo foram utilizadas duas resinas compostas, uma com matriz de resina silorane (Filtek™Silorane) e a outra com matriz de resina metacrilato (Filtek™P60). A contracção de polimerização avaliou-se pela medição da densidade, de acordo com o princípio de Arquimedes e a avaliação estatística pelo teste paramétrico “t student” à diferença dos valores esperados (p>0,05). Para a profundidade de polimerização procedeu-se à medição micrométrica das amostras, segundo a norma ISO4049:2000(E). Em ambos os estudos foram utilizadas as fontes de luz LED (Diodo Emissor de Luz) e QTH (Quartzo Tungsténio Halogéneo).ResultadosVerificou-se uma evidência estatística de que a resina composta Filtek™Silorane atinge valores de contracção de polimerização inferiores [1,14% (QTH) e 1,18% (LED)] sendo também os valores de profundidade de polimerização inferiores [(1,74mm (QTH) e 1,99mm (LED)], comparativamente com a resina composta Filtek™P60 [2,33% (QTH) e 2,42% (LED)] e [2,45mm (QTH) e 2,85mm (LED)].ConclusõesAs propriedades de contracção e profundidade de polimerização são variáveis dependentes de factores como o tipo de matriz de resina, o conteúdo e tipo de carga e a fonte de luz utilizada. A resina composta Filtek™Silorane apresentou valores de contracção e de profundidade de polimerização inferiores comparativamente com a resina composta Filtek™P60