Percorrer por autor "Pereira, Pedro Mariano"
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- Associação da má oclusão de Classe II Divisão 2 com anomalias do desenvolvimento dentárioPublication . Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina
- Avaliação da perceção estética da posição labial sagital em diferentes painéis de observadoresPublication . Viegas, Marta; Pereira, Pedro Mariano
- Avaliação da perceção estética do perfil facial em diferentes painéis de observadoresPublication . Viegas, Marta M.; Pereira, Pedro Mariano; Proença, LuísObjetivo: Avaliar se a perceção estética da convexidade do perfil facial é semelhante entre os diferentes painéis de avaliadores. Métodos: Foram utilizadas silhuetas de perfil construídas no programa Adobe Photoshop Cs5®. A partir de um perfil de referência com 12° de convexidade facial foram criadas 4 silhuetas com convexidade de 0°, 6°, 18° e 24°. Foram avaliadas por especialistas em ortodontia, estudantes de medicina dentária e por um grupo de controlo que representa a população em geral, mediante um questionário online. Resultados: Verificaram‐se diferenças estatisticamente significativas entre grupos quanto à perceção estética da convexidade do perfil facial. Os especialistas em ortodontia e os estudantes de medicina dentária consideram mais estético o perfil de convexidade 12°. A população em geral prefere o perfil de 18°. Conclusões: A perceção estética da convexidade do perfil facial não é idêntica para os especialistas em ortodontia, estudantes de medicina dentária e para o grupo de controlo que representa a população geral.
- Avaliação de perceção estética do perfil facial em diferentes painéis de observadoresPublication . Viegas, Marta; Pereira, Pedro Mariano
- Comparison of shear bond strength of metallic brackets bonded to ceramic surfaces utilizing different adhesive systems : an in vitro studyPublication . Pulido, María Belén Paz; Pereira, Pedro Mariano; Pitschielller, Ricardo; Proença, Luís; Bugaighis, ImanOBJECTIVE: To compare the shear bond strength (SBS) of orthodontic brackets bonded to three different types of ceramic surfaces (feldspathic, lithium disilicate, and zirconium) using Assure® Plus All and Transbond™ XT adhesives. MATERIALS AND METHODS: The sample comprised 72 monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic samples that were randomly divided into six groups of 12 specimens each. Three groups (G1, feldspathic ceramic; G3, lithium disilicate ceramic; G5, zirconium surfaces) were bonded to metal brackets using Assure® Plus All adhesive, whereas the remaining three groups (G2, G4, G6; with the ceramic type in the same order as that in the previous groups) were bonded to metal brackets using Transbond™ XT. The samples were then subjected to 10,000 thermocycles. The SBS was calculated using the shear tests. The site of bonding failure was classified using the adhesive remnant index (ARI) score. One-way analysis of variance (ANOVA) and Kruskal–Wallis tests were used for statistical analyses at a 5% significance level. RESULTS: Statistically significant differences were observed in the mean SBS values of the groups (P < 0.001). The mean SBS for G6 (zirconium plus Transbond™ XT) (2.52 MPa) was significantly lower than that for all other groups. Furthermore, statistically significant differences were found in the ARI score distribution among the groups (P < 0.001). Differences were identified between G6 and G3 (lithium disilicate Plus All Assure® Plus All) and G5 (zirconium plus Assure® Plus All). CONCLUSIONS: The mean bonding strength of brackets with Assure® Plus All was higher than that with Transbond™ XT for all three types of ceramics. However, all groups, except the zirconium plus Transbond™ XT group, showed acceptable bonding strength for orthodontic purposes. The application of hydrofluoric acid followed by silane and finally the Assure® Plus All adhesive system is adequate for bonding brackets to any of the ceramic tested surfaces.
- Criteria for early diagnosis of third molar agenesis : a retrospective radiographic studyPublication . Dumas, Margaux; Pereira, Pedro Mariano; Bugaighis, Iman; Retto, Paulo Fernandes; Proença, LuísObjective: To explore the association between chronological, dental and skeletal ages and early diagnosis of third molars agenesis. Material and methods: This retrospective radiographic study comprised a sample of 282 Portuguese patients (122 males and 160 females) who sought orthodontic treatment between 2007 and 2018. Each participant had panoramic and lateral cephalometric radiographs performed before and after the age of 14 years. The chronological age was categorized into three intervals between 11.0 and 13.11 years of age. The full eruption of the four-second molars was used as a criterion in determining dental age. Skeletal age was verified by the vertebral maturation method. The diagnosis of agenesis of third molars was initially performed by observation of the initial panoramic radiography undertaken before the age of 14 years. Subsequently, the diagnosis of agenesis of third molars was confirmed by visualizing the second panoramic radiography, obtained after the age of 14 years. The association between the accuracy of the diagnosis and the chronological, dental and skeletal ages was evaluated using the chi-square test, at a 5% significance level. Results: No significant association between chronological age and alterations in the diagnosis of third molar agenesis was identified. However, there was a significant association between third molar agenesis and both dental age (p<0.001) and skeletal age (p=0.006). Conclusion: The eruption of the four-second molars and the peak of growth could be considered as criteria for early diagnosis of third molar agenesis, whereas chronological age is not a reliable diagnostic indicator.
- Different manifestations of Class II Division 2 incisor retroclination – Morphologic studyPublication . Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina"Introduction: The aim of the present study was to investigate whether there is a different transverse morphologic pattern of dental arches among the different manifestations of Class II Division 2 incisor retroclination and evaluate to what extent the pattern of smaller-than-average teeth in Class II Division 2 malocclusion is common to all groups studied. This information may clarify whether different Class II Division 2 phenotypes represent a single etiology or multiple etiologies. Methods: The sample comprised 108 Class II Division 2 malocclusions which were divided into two groups according to the type of incisor retroclination: Group I composed of 43 Class II Division 2 with retroclination exclusively of the maxillary central incisors; Group II composed of 65 Class II Division 2 with retroclination of the four maxillary incisors. Maxillary and mandibular intercanine and intermolar widths as well as the mesiodistal crown dimension of the four maxillary and mandibular incisors were determined using the initial study models of patients. Mean values of all variables were compared between the two groups by gender using ANOVA. Results: From the comparison between the two groups analyzed, no statistically significant differences were found for all transverse measurements (p>0.05). For all mesiodistal measurements analyzed, statistically significant differences between the groups were only found for the mean value of both maxillary lateral incisors mesiodistal dimension in both sexes (p<0.05). Conclusions: It is not possible to attribute a characteristic pattern of dental arch width and of incisor mesiodistal dimension to the different manifestations of incisor retroclination in Class II Division 2 malocclusion."
- Different manifestations of class II division 2 incisor retroclination and their association with dental anomaliesPublication . Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina"Objective: To investigate whether there is an association between dental development anomalies (DDAs) and the different manifestations of Class II Division 2 (CII/2) malocclusion incisor retroclination. This information may clarify whether the different CII/2 phenotypes, with regard to maxillary incisor retroclination, are a single clinical entity or etiologically different entities. Design: Retrospective comparative study. Setting: Private orthodontic practice in the regions of Lisbon and Porto, Portugal Subjects and Methods: The sample comprised 115 CII/2 malocclusions distributed into 2 groups on the basis of incisor retroclination: Group I composed of 48 CII/2 with retroclination exclusively of both maxillary central incisors; Group II composed of 67 CII/2 with retroclination of all four maxillary incisors. Using the initial orthodontic records, it was determined for each patient the presence of the following DDAs: tooth impaction, tooth agenesis, maxillary lateral incisor microdontia, tooth transpositions and supernumerary teeth. Results: 55.0% of patients were diagnosed with at least one of the DDAs studied. In the total sample the prevalence rates were determined as follows: 20.0% of palatal maxillary canine impaction, 27.4% of third molar agenesis, and 15.7% of maxillary lateral incisor microdontia. No patient exhibited any transpositions or supernumerary teeth. The distribution of the DDAs studied by groups revealed a strong association of palatal canine impaction, tooth agenesis and maxillary lateral incisor microdontia with Groups II but not with Group I. Conclusion: The association of DDAs with CII/2 malocclusion is not common to all types of maxillary incisor retroclination, suggesting different etiologic bases among the different manifestations of CII/2 malocclusion incisor retroclination."
- The effect of ceramic surface conditioning on bond strength of metallic brackets : an in vitro studyPublication . Ferreira, Rita; Pereira, Pedro Mariano; Pitschieller, Ricardo; Proença, Luís; Bugaighis, ImanObjective: To compare the shear bond strength (SBS) of brackets bonded to three different types of ceramic surfaces (feldspathic ceramic, lithium disilicate ceramic, and zirconia), conditioned with either hydrofluoric acid or sandblasting, using Assure® Plus All bonding agent. Materials and methods: A total of 72 monolithic CAD/CAM ceramic specimens were divided into six groups of 12 samples. Three groups (G1: feldspathic ceramic, G3: lithium disilicate ceramic, G5: zirconia surfaces) were conditioned with 9.6% hydrofluoric acid, while the remaining three (G2, G4, G6; with ceramic type in the same order as the previous three groups) were prepared with 50 μm aluminum oxide sandblasting. Premolar brackets were bonded using light-cured Assure® Plus All. The SBS and adhesive remnant index (ARI) were recorded and submitted to inferential analysis using one-way analysis of variance and Kruskal–Wallis tests, respectively. The significance level was set at 5% (P ≤ 0.05). Results: The mean SBS values for the three different ceramic groups conditioned with hydrofluoric acid (G1: 7.2 ± 1.5 MPa, G3: 9.3 ± 2.3 MPa, G5: 8.5 ± 2.0 MPa) were significantly higher than those obtained for the groups prepared by sandblasting before bonding (G2: 7.5 ± 1.8 MPa, G4: 4.4 ± 2.0 MPa, G6: 4.3 ± 2.8 MPa). Conclusions: The hydrofluoric acid treatment produced a favorable SBS for all three examined ceramic types before bracket bonding with Assure® Plus All. In comparison, sandblasting yielded a satisfactory SBS only with feldspathic surfaces. Furthermore, the ARI indicated a higher frequency of mixed-adhesive failures except for lithium disilicate conditioned with sandblasting. Therefore, using hydrofluoric acid is likely to be especially recommended when the clinician is not aware of the brand of ceramic restorative material.