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- EditorialPublication . Fernandes, Gustavo
- Tensile strength assay comparing the resistance between two different autologous platelet concentrates (leucocyte-platelet rich fibrin versus advanced-platelet rich fibrin): a pilot studyPublication . Pascoal, Martim de Almeida Nóbrega Correia; Santos, Nuno Bernardo Malta dos; Completo, António Manuel Godinho; Fernandes, Gustavo Vicentis de OliveiraBackground: Since the leucocyte-platelet rich fibrin (L-PRF) was published in 2001, many studies have been developed, analyzing its properties, and also verifying new possibilities to improve it. Thereby, it emerges the advanced-platelet rich fibrin (A-PRF) with a protocol that optimizes the properties obtained by the L-PRF. Nonetheless, there is a gap in the literature to landmark the evolutive process concerning the mechanical properties in specific the resistance to tensile strength which consequently may influence the time for membrane degradation. Thus, this study had the goal to compare the resistance to the traction of membranes produced with the original L-PRF and A-PRF protocols, being the first to this direct comparison. Findings: The harvest of blood from a healthy single person, with no history of anticoagulant usage. We performed the protocols described in the literature, within a total of 13 membranes produced for each protocol (n = 26). Afterward, the membranes were prepared and submitted to a traction test assessing the maximal and the average traction achieved for each membrane. The data were analyzed statistically using the unpaired t test. Regarding average traction, A-PRF obtained a value of 0.0288 N mm−2 and L-PRF 0.0192 N mm−2 (p < 0.05 using unpaired t test). For maximal traction, A-PRF obtained 0.0752 N mm−2 and L-PRF 0.0425 N mm−2 (p < 0.05 using unpaired t test). Conclusion: With this study, it was possible to conclude that indeed A-PRF has a significative higher maximal traction score and higher average traction compared to L-PRF, indicating that it had a higher resistance when two opposing forces are applied.
- A new design of a multifunctional abutment to morse taper implant connection: experimental mechanical analysisPublication . Gehrke, Sergio Alexandre; Dedavid, Berenice Anina; Fernandes, Gustavo Vicentis de OliveiraThe objective of this study was to evaluate a new design of multifunctional abutment for Morse taper implant connections, relative to the retentive stability after the application of cyclic loads in cemented and screwed crowns. Multifunctional abutments with two different angulations in the seating portion of the crown were tested, forming 2 groups (n = 30 samples per group): Group Abut11, where Smart abutments with an angle of 11.42° were used; Group Abut5, where Ideale abutments with an angle of 5° were used. Fifteen samples from each group received cemented crowns (CC) and another fifteen screwed crowns (SC). All crown samples were subjected to the mechanical cycling test at 360,000 cycles at a frequency of 4 Hz and 150 N of the load. The samples with CC were subjected to the tensile test to remove the crowns, while in the samples with SC, the detorque value of the fastening crown screws was measured. The mean tensile strength value of CC in the Abut11 group was 131.9 ± 13.5 N and, in the Abut5 group was 230.9 ± 11.3 N; while the detorque mean value in samples with SC 5.8 ± 1.8 N for the Abut11 group and, 7.6 ± 1.1 N for Abut5 group. Significant statistical differences were found between the two groups in both situations tested (p < 0.05). The multifunctional abutments, presenting a lesser angulation of the crown-seating portion, showed higher values of retention of the CC and a lesser screw loosening of torque of the fixing screws in the SC after the application of cyclic loads when compared to the abutments with more angulation in the crown-seating portion.
- Presence of gingival recession or noncarious cervical lesions on teeth under occlusal trauma: a systematic reviewPublication . Tróia, Pedro Maria Bastião Peliz Senos; Spuldaro, Tobias Rauber; Fonseca, Patrícia Alexandra Barroso da; Fernandes, Gustavo Vicentis de OliveiraThe goal of this research was to carry out a systematic review to verify the possible influence of occlusal factors on the occurrence of gingival recession and noncarious cervical lesions. To answer the specific research question—whether gingival recession or noncarious cervical lesions on teeth are present under occlusal trauma—a bibliographic search was conducted at MEDLINE/PubMed, Web of Science, and Gray Literature databases focusing on articles published, following strict inclusion cri- teria based on randomized clinical trials, controlled clinical studies, and case series, with restricted language (English) and publication date between March 2010 and March 2020, considering patients with occlusal trauma and gingival recession/non-carious cervical injuries. Questionnaires, animal or laboratory studies, case reports, and interviews were excluded. First, the title and/or abstract of the articles obtained were analyzed and, finally, a full-text reading was performed. Given the amount and diversity of the final studies, a qualitative analysis was made. Based on the established criteria, it was possible to obtain an initial 757 articles. After screening, five articles were included, and then qualitative analysis was performed. The results described in the articles were different, given the heterogeneity of the articles subjected to analysis. A few studies were published in the past 10 years, suggesting that the traumatic occlusion seems to be associated with the occurrence of the noncarious cervical lesion while it is not possible to arrive at a conclusion with regard to the association of gingival recession and occlusaltrauma.
- De‐epithelialized connective tissue graft and the reminiscent epithelial content after harvested by the Harris’ technique: a histological and morphometrical case seriesPublication . Maia, Vinícius Tadeu Gonçalves; Kahn, Sérgio; Souza, Alex Balduino de; Fernandes, GustavoIntroduction: The remaining epithelial layer existent in connective tissue graft (CTG) harvested from the hard palate, which underwent de‐epithelization outside the oral cavity, can be histologically detected unless it is completely removed. Its presence may cause adverse esthetics results, affecting thus the color and texture of the receptor site, and an increased risk of presence of scar tissues after surgical procedures. The proposal of this study was to evaluate the CTG (histological and morphometrically) collected from the hard palate using the Harris’ technique, removing the epithelial layer outside the mouth, assessing the remaining presence of epithelial tissue. Case Series: Fourteen patients (14CTGs) were included in the present case series study, therefore there was two dropouts. A small part of the tip of the graft was harvested and fixed in formalin solution for histological processing, staining, and then to be morphometrically analyzed. The epithelial tissue and CTGs were assessed by three calibrated and double‐blinded professionals. All information was compiled and performed the statistical analysis. CTGs obtained had a width average of 1224.26μm. There was no presence of any residual of the epithelium in three samples, whereas only one had the epithelium tissue covering the entire connective layer. Furthermore, seven samples (approximately 50%) had the presence of epithelium. Conclusion: Within the limitation of this study, there was incomplete removal of the epithelial layer after harvesting the CTG using the Harris’ technique (44.32%), most likely due to its histological persistency, suggesting to be inaccurate the clinical removal.