Papers by Maria João Calheiros Lobo
European Journal of Dentistry, Dec 28, 2023
Objectives Maxillary lateral incisor agenesis (MLIA), treated orthodontically by space opening, r... more Objectives Maxillary lateral incisor agenesis (MLIA), treated orthodontically by space opening, requires complimentary aesthetic rehabilitation. Resin-bonded bridges (RBBs) can be equated as interim rehabilitation until skeletal maturity is achieved to place an implant-supported crown or as definitive rehabilitation in case of financial restrictions or implant contraindications. Scientific evidence of the best material must be confirmed in specific clinical situations. Computer-aided design and computer-aided manufacturing (CAD/CAM) materials are promising versatile restorative options. This study aimed to identify a straightforward material to deliver interim or definitive RBBs for nonprepared tooth replacement in MLIA. Materials and Methods Single-retainer RBB made from CAD/CAM ceramic blocks (Vita Enamic [ENA], Suprinity [SUP], and zirconia [Y-ZPT]) and a three-dimensional (3D) printed material (acrylonitrile butadiene styrene [ABS]) were evaluated by shear bond strength (SBS) and mode of failure, after adherence to an artificial tooth with RelyX Ultimate used in a three-step adhesive strategy. Statistical Analysis The load to fracture (N) was recorded, and the mean shear stress (MPa) was calculated with standard deviations (SD) for each group and compared between materials using boxplot graphics. One-way analysis of variance (ANOVA) followed by the Tukey-Kramer post hoc test was used to compare the differences All authors contributed equally to this work.
Coatings
Traditional load-to-failure tests fail to recreate clinical failures of all-ceramic restorations.... more Traditional load-to-failure tests fail to recreate clinical failures of all-ceramic restorations. Experimental fabrication, similar to prosthetic laboratory and clinical procedures, best predicts future clinical performance. A hybrid ceramic adherend, mechanically similar to a human tooth, was tested by comparing the shear bond strength (SBS) and fracture mode of four restorative materials adhered with a dual-cure adhesive cement. Surface energy, shear bond strength (SBS), and fracture mode were assessed. Vita Enamic (ENA), Vita Suprinity (SUP), Vita Y-TPZ (Y-ZT), and a nanohybrid composite (RES) (control group) cylinders, adhered with RelyX Ultimate to ENA blocks were assembled in experimental specimens simulating a 3-unit resin-bonded dental bridge. The ENA adherend was ground or treated with 5% hydrofluoric acid for 60 s. Monobond Plus was used as the coupling agent. Mean shear stress (MPa) was calculated for each group. Forest plots by material elaborated after calculating the d...
Materials
Self-adhesive resin cements (SARCs) are used because of their mechanical properties, ease of ceme... more Self-adhesive resin cements (SARCs) are used because of their mechanical properties, ease of cementation protocols, and lack of requirements for acid conditioning or adhesive systems. SARCs are generally dual-cured, photoactivated, and self-cured, with a slight increase in acidic pH, allowing self-adhesiveness and increasing resistance to hydrolysis. This systematic review assessed the adhesive strength of SARC systems luted to different substrates and computer-aided design and manufacturing (CAD/CAM) ceramic blocks. The PubMed/MedLine and Science Direct databases were searched using the Boolean formula [((dental or tooth) AND (self-adhesive) AND (luting or cement) AND CAD-CAM) NOT (endodontics or implants)]. Of the 199 articles obtained, 31 were selected for the quality assessment. Lava Ultimate (resin matrix filled with nanoceramic) and Vita Enamic (polymer-infiltrated ceramic) blocks were the most tested. Rely X Unicem 2 was the most tested resin cement, followed by Rely X Unicem...
Dental and Medical Problems
Background. Mandibular second premolar (M2P) agenesis results in the second primary molar (2pm) r... more Background. Mandibular second premolar (M2P) agenesis results in the second primary molar (2pm) retention, infraocclusion, a reduced alveolar height and width, the supraeruption of antagonists, or the movement of the adjacent teeth. Infraocclusion affects the survival of the retained 2pm to a greater extent than root resorption. Objectives. The aim of the study was to evaluate the lifespan of the primary molar as a substitute, with root quality and occlusal adaptation, in cases of M2P agenesis in a low-income population to determine if the attitude of just vigilance could be the best clinical option whenever other clinical problems are absent. Material and methods. A total of 12,949 orthopantomograms were analyzed. Sixty-one patients (25 males and 36 females aged 7-36 years) were divided into group 1 (the first permanent molar in occlusion) and group 2 (the second permanent molar also in occlusion). Vertical positioning to the occlusal plane, root condition and the movement of the adjacent teeth were evaluated. Results. Despite the study having a cross-sectional design, root resorption, infraocclusion, the distance between the first permanent molar and the first primary molar or the first permanent premolar, and the width of the 2pm were correlated with age. The 2pm root resorption increased with age, which was more pronounced when the second permanent molar was also in occlusion. The mesial movement of the adjacent teeth was absent in all groups. The 2pm was often occluded, but infraocclusion increased with age. Age periods of 11-15 years and 21-25 years were critical for the primary tooth loss. Conclusions. The second primary molar remains functional in the mandibular arch for up to 25 years. A well-documented no-intervention attitude based on clinical and radiographic data must be weighed in cases without orthodontic issues or with financial constraints.
Advances in Experimental Medicine and Biology, 2019
The preanalytical phase of saliva proteomics/peptidomics, which includes sample collection, handl... more The preanalytical phase of saliva proteomics/peptidomics, which includes sample collection, handling, and storage, represents a major challenge for any researcher that envisions sensitive and high-throughput analyses, coupled to well-controlled study design. The methodology used to collect saliva determines the contribution of each salivary gland to saliva composition with impact on data retrieved from proteomics/peptidomics. The awareness of the importance of this step in the analysis of saliva has prompted the proposal of several collection strategies. Moreover, numerous commercial devices are available in an attempt to routine the procedures. However, whatever the chosen method, procedures should be kept simple, standardized to get better reproducibility and repeatability on saliva proteomics analysis. Sample preservation is also a key step in saliva proteomics/peptidomics, and the implemented lab procedures should avoid posttranslational modifications such as proteolysis, as well as protein precipitation.In this chapter, we provide recommendations for saliva sampling and preservation, envisaging to standardize procedures that facilitate the use of saliva in clinical applications and the translation of proteomics data to diagnosis and/or definition of therapeutic targets.
PROTEOMICS - Clinical Applications, 2011
Proline-rich proteins (PRPs) are the most complex family of salivary peptides with distinct isofo... more Proline-rich proteins (PRPs) are the most complex family of salivary peptides with distinct isoforms and PTMs. Up to date, only the serine phosphorylation at positions 8, 17, and 22 have been experimentally observed on acidic PRP (aPRPs), and at position 8 on basic PRP1 and 2. The presence of a glucoronyl group at Ser17 was also noticed on aPRP. The main goal of this study was to identify new PTMs and distinct isoforms of salivary PRPs using LC-MALDI-TOF/TOF. Through the salivary peptidome characterization of 20 different subjects from Control, Diabetic, and Head and Neck Cancer groups, it was possible to identify the following species: (i) N-glycosylation sites: two in basic proline-rich protein 2 (bPRP2), one in bPRP3 and one in bPRP4; (ii) O-glycosylation sites: two in bPRP2 and one in aPRP; (iii) other terminal monosaccharide sites: six in bPRP1, two in bPRP2 and two in bPRP3; (iv) other modifications such as N-terminal pyro-Glu (two in bPRP1, six in bPRP2, eight in bPRP3 and nine in bPRP4); (v) phosphorylation in serine, three in bPRP1, one in bPRP2, one in bPRP3 and one in aPRP1; (vi) bPRP1 (allele S, allele M and variant CP5) and bPRP4 (allele M). In summary, salivary peptidome data analysis allowed the identification of 45 new PRPmodified residues, mainly due to glycosylation, phosphorylation and conversion of Gln to pyro-Glu. Moreover, comparing all subject groups, it was noticed a predominance of N-acetyl hexosamine modification on bPRPs in the Head and Neck Cancer patients.
ABSTRACT Objectives: To evaluate morphological changes at gingival tissue of periodontitis patien... more ABSTRACT Objectives: To evaluate morphological changes at gingival tissue of periodontitis patients with or without diabetes. Quantify total collagen and analyze the thickness and arrangement of collagen fibers, and the frequency of immune cells. Determine the IL-;, IL-6, TNF-α;, MMP-2, MMP-9 and VEGF levels in gingival crevicular fluid (GCF). Methods: The study population included six controls, six patients with periodontitis and six diabetic type 1 patients with periodontitis followed at the endocrinology service of So Joo Hospital(Oporto, Portugal). Gingival biopsies were harvested before tooth extraction, treated as histological samples and stained with hematoxilin-eosin and sirius red. Several tissue sections were analyzed by light microscopy. GCF was collected from selected sites with an absorbent paper strip, during 30 seconds. Strips were immediately placed in a microtube containing 100 l of buffer solution (50mM Tris-HCl pH 7.4, 200mM NaCl, 10mM CaCl2, 0.02% Triton X-100). Blood or saliva contaminated strips were excluded. After 10 minutes centrifugation at 13000g, supernatant was stored at -70 C. IL-β;, IL-6, TNF-α;, MMP-2, MMP-9 and VEGF quantities were determined using a multi-plex fluorescent bead-based immunoassay (BIO-RAD). Results: The results showed that periodontal disease is characterized by marked inflammation, increase in inflammatory cells number, destruction of reticulin fibers and accumulation of thick collagen fibers. Diabetic patients present even deeper alterations of the collagen fibers arrangement. The levels of MMP-2 and MMP-9 were increased in periodontitis patients, especially in diabetics. Conclusion: Diabetes promotes periodontitis evolution apparently by exacerbation of the inflammatory response and by affecting tissue repair, namely by activation of metalloproteinase's resulting in an imbalance on collagen metabolism. FCT grant: PTDC/QUI/72683/2006" and PhD fellowship SFRH/BD/30124/2006.
Proteomics of Human Body Fluids, 2007
Page 1. 347 From: Proteomics of Human Body Fluids: Principles, Methods, and Applications Edited b... more Page 1. 347 From: Proteomics of Human Body Fluids: Principles, Methods, and Applications Edited by: V. Thongboonkerd © Humana Press Inc., Totowa, NJ 16 Proteomics of Human Saliva Francisco ML Amado, Rui MP Vitorino, Maria JC Lobo, and Pedro MDN Domingues ...
Bulletin du Groupèment international pour la recherche scientifique en stomatologie & odontologie, 2006
Caries onset and progression is influenced by diverse bacterial, dietary, environmental, socioeco... more Caries onset and progression is influenced by diverse bacterial, dietary, environmental, socioeconomic and physiological risk factors. The most significant markers include caries experience, the concentrations of mutans-group streptococci and lactobacilli, as well as protective factors, such as the buffering capacity of saliva. The aim of this study was to evaluate and compare caries risk factors. The salivary parameters determined include: buffer capacity, cariogenic bacteria counts, pH, flow rate and total protein content. Individual aspects including hygiene and diet habits were also considered. Results showed that the value corresponding to the difference of stimulated saliva pH and resting saliva pH is positively correlated with DMFT index. Lactobacilli were positively correlated with mutans streptococci, as previously described for caries diagnostics. However, the results of this study were inconclusive, showing that salivary tests parameters either as single test or even in c...
ABSTRACT Descrevem-se três tratamentos intercetivos em adolescentes com tendência para a impactaç... more ABSTRACT Descrevem-se três tratamentos intercetivos em adolescentes com tendência para a impactação de caninos maxilares. Nestes casos clínicos podese observar o quanto a detecção precoce dos caninos maxilares impactados e consequente tratamento intercetivo reduz a duração do tratamento, a complexidade e os custos. No primeiro caso, uma Classe I, o tratamento por extração programada dos caninos decíduos foi suficiente para evitar a impactação dos caninos definitivos. No segundo caso, após a extração do canino decíduo anquilosado, também foi necessário corrigir a posição palatinizada do incisivo lateral , que foi conseguida após o desgaste oclusal seletivo do canino inferior decíduo. No terceiro caso, devido a uma impactação alta e horizontal do canino com germens dos pré-molares mal posicionados, o tratamento intercetivo não foi suficiente para melhorar a erupção do canino. Neste último caso, realizou-se a extração programada dos molares decíduos sem extração dos caninos decíduos, numa primeira fase, seguida de uma segunda fase de tratamento com aparelho ortodôntico fixo para corrigir a posição da raiz do primeiro pré-molar. Após este procedimento efectuou- se a tração do canino permanente.
International Orthodontics, 2011
L'AILM peut influer sur la longueur du maxillaire et sur... more L'AILM peut influer sur la longueur du maxillaire et sur la hauteur antérosupérieure de la face, ce qui peut avoir un impact négatif sur sa croissance potentielle. Il n'ya aucune corrélation entre l'AILM et les modifications de l'inclinaison du plan palatin, la hauteur du maxillaire, l' ...
PROTEOMICS, 2004
The determination of salivary biomarkers as a means of monitoring general health and for the earl... more The determination of salivary biomarkers as a means of monitoring general health and for the early diagnosis of disease is of increasing interest in clinical research. Based on the linkage between salivary proteins and systemic diseases, the aim of this work was the identification of saliva proteins using proteomics. Salivary proteins were separated using two-dimensional (2-D) gel electrophoresis over a pH range between 3-10, digested, and then analyzed by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF)-TOF mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Proteins were identified using automated MS and MS/MS data acquisition. The resulting data were searched against a protein database using an internal Mascot search routine. Ninety spots give identifications with high statistical reliability. Of the identified proteins, 11 were separated and identified in saliva for the first time using proteomics tools. Moreover, three proteins that have not been previously identified in saliva, PLUNC, cystatin A, and cystatin B were identified.
Journal of Separation Science, 2008
The present study proposes a strategy for human in vivo acquired enamel pellicle (AEP) peptidome ... more The present study proposes a strategy for human in vivo acquired enamel pellicle (AEP) peptidome characterisation based on sequential extraction with guanidine and TFA followed by MALDI-TOF/TOF identification. Three different nanoscale analytical approaches were used: samples were subjected to tryptic digestion followed by nano-HPLC and mass spectrometry (MS and MS/MS) analysis. Undigested samples were analysed by LC-MS (both linear and reflector modes) and LC-MS/MS analysis, and samples were subjected to nano-HPLC followed by on-plate digestion and mass spectrometry (MS and MS/MS) analysis. The majority of the identifications corresponded to peptide/protein fragments of salivary protein, belonging to the classes: acidic PRPs, basic PRPs, statherin, cystatins S and SN and histatin 1 (all also identified in intact form). Overall, more than 90 peptides/proteins were identified. Results clearly show that peptides with acidic groups are enriched in the TFA fraction while peptides with no acidic or phosphate groups are prevalent on the guanidine extract. Also, phosphorylated peptides were observed mainly on the TFA fraction. Fragments present in the AEP show a predominance of cleavage points located at Arg, Tyr and Lys residues. Obtained data suggest that proteolytic activity could influence AEP formation and composition.
Expert Review of Proteomics, 2005
Interest in the characterization of the salivary proteome has increased in the last few years. Th... more Interest in the characterization of the salivary proteome has increased in the last few years. This review discusses the different techniques and methodologies applied to the separation and identification of salivary proteins. Nowadays, proteomic techniques are the state of the art for the analysis of biologic materials and saliva is no exception. 2D electrophoresis and tryptic digest analysis by mass spectrometry are the typical methodology, but new approaches using 2D liquid chromatography/mass spectrometry methods have already been introduced for saliva analysis. Due to their important physiologic role in the oral cavity, low-molecular-weight proteins and peptides are also included in this article and the methodologies discussed.
Expert Review of Proteomics, 2010
In recent years, there has been an increased interest in the study of saliva. This bodily fluid c... more In recent years, there has been an increased interest in the study of saliva. This bodily fluid contains a vast number of protein species, the salivary peptidome, of low molecular weight, comprising approximately 40-50% of the total secreted proteins, in addition to peptides generated by proteolysis of proteins of different sources. Owing to the presence of other components, in particular of mucins and enzymes, some distinctive requirements and precautions related to sample collection, time of analysis, sample preservation and treatment are necessary for the successful analysis of salivary peptides. More than 2000 peptides compose the salivary peptidome, from which only 400-600 are directly derived from salivary glands, suggesting an important qualitative peptide contribution of other sources, namely of epithelial cells. Proteolysis events are the main supply for the peptidome and considerable efforts have been made to identify the resulting fragments, the cleavage sites and the involved proteases. The salivary proteins more prone to proteolysis are proline-rich proteins (PRPs; acidic PRPs and basic PRPs), statherin, histatins and P-B peptide. Gln-Gly cleavages are largely associated with PRP classes, while Tyr-Gly cleavages are related to histatin 1 and to the P-B peptide. The interest in saliva has been growing for clinical purposes, as it is an alternative sample to other traditionally bodily fluids, such as blood or urine, since it involves an easy and noninvasive collection. In fact, apart its usefulness as a source of information for prognosis, diagnosis and treatment of oral diseases, such as Sjogren's syndrome, gum disease, tooth decay or oral cancer, saliva might also be seen as a potential tool to the diagnosis of systemic diseases. Owing to the enormous amount of previously discovered salivary peptide species, in this article, we present an attempt to harmonize the nomenclature, following International Union of Pure and Applied Chemistry recommendations.
European Journal of Oral Sciences, 2006
Uploads
Papers by Maria João Calheiros Lobo