Repositório RCAAP

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Background: Clinical problems are commonly reported by users of mandibular dentures, such as inability to comminute foods, decreasing on self-confidence, quality of life, social contact and personal satisfaction. Purpose: the aim of this study was to measure the impact of the use of mandibular implant fixed denture with reduced number of implants on chewing performance, nutritional status and quality of life. Materials and Methods: a clinical retrospective study involving edentulous patients that received installation of mandibular implant-supported prosthesis and new upper denture. The masticatory performance, quality of life and nutritional status before and after installation of the new prostheses (CD = before treatment, ISP30 = 30 days, and ISP150, five months after the installation of new prostheses) were measured. Masticatory performance was assessed by the colorimetric method; the quality of life was recorded using the Test Impact Profile-14 Brazil (OHIP-14Br) and the nutritional status determined by nutritional markers through hematology exams. Data were analyzed using of one-way Anova, Pearson correlation between masticatory performance and quality of life and Pearson correlation between masticatory performance and nutritional indexes. Results: significant improvement of quality of life index (p<0,05) was observed for masticatory performance (p< 0,05) after PTIS150. No significant difference was found between the evaluation times for nutritional markers (p< 0,05). Low correlation was found between masticatory performance and quality of life (CD: p = 0,187, ISP150: p = 0,732). Conclusions: positive impact of quality of life and masticatory performance was found, however no significant improvement was found for nutritional indexes.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Objective: To access and evaluate the outcomes of a treatment concept for rehabilitation of atrophic mandible associating immediate loading to tilted implants and angled abutments Materials and Methods: Records of six women and four men, mean age 61.5, were included. Radiographic data performed in 2 stages (T1 and T2) and data of patient satisfaction with the mandibular prosthesis, performed in 3 stages (T0, T1 and T2) by a satisfaction evaluation survey including questions on general satisfaction, retention, aesthetics and chewing up to 6 months, were accessed on records of patients previously submitted to rehabilitation with conventional dentures in the maxilla and immediate protocol on 3 implants in mandible. Radiographs were digitized and evaluated using the UTHSCSA Image Tool® software. Results: The survival rate of implants and prostheses were, respectively, 93.3% and 90.0%. After delivering the mandibular protocol, no significant differences on marginal bone loss over time (T1 and T2), for both tilted implants (Mesial - p=0.8890/Distal p=0.3740) as straight (Right/Left side - p=0.680). Regarding satisfaction with the prosthesis, significant differences were found between T0-T1 and T0-T2. No significant differences were observed when the comparison was made between T1-T2. Conclusion: The combination of angled abutments and tilted implants in the immediate rehabilitation of edentulous atrophic mandible seems to be a promising treatment.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Airway dimensions are determined by anatomical structures such as soft tissues, musculature and craniofacial bones related to the pharynx. Anatomical alterations of those structures can make the superior airway space narrower thus interfering in its functional pattern and turns out to be an important etiological factor in a disorder known as Obstructive Sleep Apnea Syndrome (OSAS), often seen in Class II facial pattern patients. Orthognathic surgery (OS), used to correct dental-skeletal deformities, has turned out to be efficient in the treatment of serious OSAS cases when compared to other procedures such as uvulopalatopharyngoplasty, suspension of the hyoid and advancement of the genioglossus. However, it can have a positive or negative effect on patients\' sleep quality. Patients with Class III dental skeletal deformities show a decrease in the superior airway space (SAS) after undergoing OS for mandibles setback, although it is not often dealt with in the literature. Many studies measuring posterior airway changes use lateral cephalometries to analyze such alterations, but those have limitations as they use a bidimensional method (2D) to measure tridimensional structures (3D). Computer tomographies make it possible to reconstruct 3D structures and enable a more accurate measurement to be done. The combination of both assessment techniques, 2D and 3D, contribute to standardization, surgical planning, and to the obtainment of more precise results. The aim of this retrospective study was to evaluate SAS alterations in Class II patients undergoing OS with counterclockwise rotation of Maxillo Mandibular Complex (MMC) using Cone-beam computer tomography (CBCT). The computer tomographies images obtained from a DICOM file (Digital Imaging and Comunications in Medicine) were exported into the sofware program Dolphin Imaging 11.5 (Dolphin Imaging and Management Solutions, Chatsworth,CA,USA) to do 3D measurement of surface area (SA), minimal axial area (MAA) and posterior air space volume (VOL). Twenty-three patients with a history of respiratory disorders were assessed, 15 female and 8 male, with average age of 34,04 years (16 to 64 years), subjected to computer tomographies at two intervals: T1 (pre-operative) and T2 (six month minimum post-operative). The data obtained were tabulated and statistically analyzed. A t-Student and Wilcoxon paired test was used and the result obtained was statistically significant (p<0.05) regarding an increase in SAS in patients undergoing OS with counterclockwise rotation of the MMC in this study.

The orthognathic surgery is indicated for correction of severe skeletal disharmonies. Changes in condylar morphology after this surgery are more frequent in class II deformities associated with condylar hypoplasia. The aim of this study was to evaluate linear, angular, and volumetric changes in condylar morphology after orthognathic surgery with counterclockwise rotation of the maxillomandibular complex, from cone -beam CT scans pre and post-surgical, obtained with patients positioned with the Frankfurt plane parallel to floor. The CT images of 23 Class II patients operated on between the years 2011 and 2012 were converted into DICOM file (Digital Imagining and Communications in Medicine) and exported to the Dolphin Imaging® software for analysis two and three-dimensional in the coronal and sagittal planes. Statistical analysis of Shapiro-Wilk normality test, which defined the Student t test for normally distributed variables (P > .05) and the Wilcoxon test for variables not normally distributed (P < .05). The study showed statistically significant differences between preoperative and postoperative time to the variables: height to the articular fossa of the right condyle (right X2), posterior distance from the right condyle to articular fossa in the sagittal plane (right PS), upper distance from the right condyle to articular fossa (right SS) and anterior distance from the left condyle to the articular fossa in the sagittal plane (left AS). The variables for the analysis of 2D surface area and 3D volume showed no statistically significant differences between pre -and postoperatively. Some patients in this study had healthy temporomandibular joints (TMJ), others had disc displacement and good function. It was concluded this surgical technique is safe and clinically stable and that the results observed in this study suggest a trend for condylar remodeling, physiological and adaptive, with apposition bone in some regions and bone resorption in others, changing the morphology of the condyle and in their spatial position in the articular fossa for this surgical technique with counterclockwise rotation of the maxillomandibular complex and mandibular advancement. There is need for further studies to clarify this hypothesis scientifically.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Investigations about nanotechnology and the development of new materials for various applications is the fact evidenced by literature. There is, today, the lack of consensus among researchers about what the ideal material to be used as endodontic filling. Thus, the present study evaluated the synthesis, characterization and histological evaluation of zinc oxide nanocrystals through biological tests, according to criteria established by the International Dental Federation. The chemical composition and purity of the material were verified by Micro-Raman spectroscopy (Raman) and their spatial structure, phase and average of the particle size by X-ray diffraction (XRD). Ten guinea pigs (\"Guinea Pig\"), divided into experimental periods of 30 and 90 days, were used. Two intra-osseous implants were performed in each animal in the region between the mandibular symphysis, and incisors. To pack the materials tested, Teflon cups were used with their side as a control. After the experimental periods, animals were sacrificed and specimens were prepared for the routine histological examination. The nanocrystals of zinc oxide presented with a size of 21nm, hexagonal structure, not observed the presence of impurities. Tissue reaction to zinc oxide nanocrystals showed predominantly absent/mild intensity, characterized the material as biocompatible in the model test, according to the protocols of the FDI and ANSI/ADA.

The present study had the purpose of analising microscopically the pulp tissue of human traumatized teeth with clinical diagnosis of pulp necrosis, evaluating the presence of microorganisms in the root canal and correlating clinical and radiographic criteria with microscopic and microbiologic findings. Twenty teeth were selected with intact crown that had injury in the periodontal tissues and that during the follow-up of the pulp condition, by clinic and radiographic evaluations, the pulp necrosis was clinically diagnosed. Microbiologic collect was performed in the root canal and the pulp tissue extirpated was stained with hematoxylin and eosin for microscopical evaluation and the adjacent slide stained to the Brown and Brenn method. The statistic and descriptive analyses (Analyse of diagnosis, Wilcoxon`s Test and Linear Regression Test) enabled the following observations: from 20 traumatized teeth 3 did not present enough pulp tissue to have a microscopic evaluation performed and 17 showed pulp necrosis; in 12 out of 17 pulps the presence of microorganisms could be conformed by Brown and Brenn method; the microbiological evaluation presented microbial development in 17 root canals (85,0%), with predominance of facultative anaerobics; none of clinical criteria used were pathognomonic (100,0%) to the diagnosis of the pulp necrosis in the traumatized teeth. Testings that showed more sensibility were termic pulp testing relative to hot (90,0%), relative to cold (85,0%) and the vertical percussion testing (75,0%); this last one also showed high sensibility (80,0%) in observating present microorganisms in the root canal; either the apical periodontal space condition (normal or increased) or the period of time the injury until the endodontic intervention did not show statistically significant correlation to the number of present microorganisms in the root canal, except the buccal streptococcus, which number showed bigger as the time increased. It was conclude that among the 20 traumatized teeth with clinical diagnosis of pulp necrosis, 3 did not show pulp to allow a microscopic exam and 17 showed necrotic pulps in the microscopic exam; 85,0% showed microorganisms in the root canal and a positive correlation was observed between the clinic and radiographic criteria used to the pulp necrosis diagnosis with microscopic and microbiologic findings.

According to Morin apud Coelho (2002), there is increasingly broad, deep and serious inadequacy between the separated, fragmented, and compartmentalized knowledge among disciplines one the one hand, and the increasingly multidisciplinary, cross-sectional, multidimensional, transnational, global and planetary realities and problems on the other. (...) Hyperspecialization prevents what is global (which it dilutes) from being seen. (...) The breakdown of disciplines (in teaching) makes it impossible to learn what tissue is together , that is, the complex, in accordance with the original sense of the term. As contradictory as it may seem, since as far as is known, all if not almost all the Graduation Courses in Dentistry propose to educate a General Clinic Dental Surgeon. However, the great challenge at present, is to educate this General Dental Surgeon based on a model centered on principles of integrality, inter-disciplinary, transdisciplinary and multi-professionalism, preparing him/her to promote health, prevent and care for people, without disqualifying him/her for being a General Clinician; on the contrary, educating him/her to be capable of acting with quality and resolution in 80 to 85% of the prevalent nosology. Thus, the aim of this work was to analyze structural and contemporary Conjunctural paradigms, and from this, construct a curricular model which, in accordance with the various forms of academic structures, could confer a greater or lesser degree of freedom on the organization of contents, as well as various possibilities of using practical scenarios, and thereby contribute, as a reference, to implanting and implementing the National Curricular Guidelines on Graduation Courses in Dentistry, foreseen in the CNE/CES Resolution 3 of 19/02/02. The work consisted of a study of the retrospective and prospective type, by means of a bibliographic survey and life experiences, with regard to the contemporary paradigms, whether they be Structural or Conjunctural, which at present guide the construction of a curricular model for the Graduation Course in Dentistry. The Structural paradigms (developmental and legal bases) were understood as being those that constitute the foundations of the legal aspects that involve the educational process, and are determined by Decrees, Resolutions and other legal diplomas. The Conjunctural paradigms (circumstantial bases) were the contributory, indicative, signalizing, propositional or inductive factors for improving and suiting the educational process to be in consonance with our reality. In the light of the guidance, difficulties and challenges, the paradigms were analyzed and discussed, and at the end of the work, the essential stages in constructing a curricular model, the form or organization and development of the contents, as well as the other characteristics necessary for educating a dental surgeon, capable of being inserted in a natural and productive manner in the various systems that provide health services, particularly the Single Health System (SÚS) were presented.

The research approached the selective process used by the Brazilian Colleges in the admission of candidates to the higher education. The raising demand for vacancies in the public universities contributed to the exceeding competition in the college entrance exams, what rebounded in the way of high school conduction, that has acquired propaedeutic characteristics. The negative reflection about the objectives of this level of the teaching trigged off searches for the alternatives selective process, that could rescue and encourage the realization of the purposes originally offered to the high school. New proposals acquired impulse with the promulgation of the Lei de Diretrizes e Bases da Educação Nacional (LDB) nº 9394, in 12/20/1996, that extinguished the traditional college entrance exams exclusiveness as the selection s way. The Universidade Federal de Uberlândia implanted the Alternative Process to College Entrance PAIES, a process of evaluation in series, with exams aplicated in the end of the three series of high school. The candidates that reach the best general results in the three evaluations, since 1997, are selected to occupy 25% of the offered vacancies, yearly, by the higher courses of UFU; entering always in the first semester. While the traditional college entrance exams selects for the others 75% of the offered vacancies; that enter in both semesters. The aim of this work was to know the factor of predictive validate of these two selective processes, through the comparison of the academic performance of the student s groups of the Faculdade de Odontologia da Universidade Federal de Uberlândia (FOUFU) admitted by traditional college entrance exams and by Alternative Process to College Entrance (PAIES). The subjects of the research were the students of the 51º to 56º groups of the Odontology Course, examined in pre established periods of the course, by analysis of the official registers of notes and subjective evaluation of the students and the teachers, by the application of the questionnaire. The data, collected between 2002/2 and 2003/2, were treated statistically and analyzed qualitatively and quantitatively. The results allowed to conclude that the admitted students by Alternative Process to College Entrance (PAIES) presented best academic performance and best competence of learning during the graduation, and suggested that this selective process present level of factor of predictive validate higher then the traditional college entrance exams.

The delay in pouring of elastomers impressions can be the cause of possible dimensional alterations of the working casts, mainly when they are under influence of other factors that interfere on its dimensional stability. The purpose of this research was to test the hypothesis that the delay in pouring of the casts after the attainment of impressions of polysulfide and polyether has influence in dimensions of the model obtained, using a method that simulates the conditions of the practical clinic. It had been used a polysulfide (Permlastic - Kerr) and a polyether (Impregum 3M ESPE) to mold a master model with two pillars: 1 first human premolar and 1 first human molar prepared for fixed partial denture with three elements. Six reference points had been established in each tooth, resulting in seven measurements: (mesiodistal, buccopalatine and cervico-occlusal for both, and the interpillars distance). Molds were obtained with acrylic resin custom-trays, stored for the times of 30min, 2h and 12h (n = 10) and poured with dental stone type IV (Vel-Mix - Kerr). Three examiners measured the master model and the samples in an optical microscope (Mitutoyo). The measurements of each sample had been compared with the master model by means of Student s t test, and between groups by means of two-way ANOVA, and Tukey s test (P<.05). The average distances for polysulfide varied from 0 to 23&#956;m for the time of 30min, 4 to 30&#956;m for 2h and 1 to 22&#956;m for 12h of storage. For the polyether, it was from 1 to 43&#956;m for 30min, 2 to 44&#956;m for 2h, and 0 to 23&#956;m for 12h. The polysulfide and the polyether generated models with alterations in at least one of the distances, but only one of them was influenced by the storage time. Almost all the alterations were clinically acceptable.

The study aimed to evaluate the abrasive microdesgaste bovine enamel submitted to bleaching. Methods: Samples were submitted to dental bleaching, and their resistance to microdesgaste evaluated by testing microabrasion (Calowear Tester). Bovine incisors in which ninety applied bleaching products in gel form, in enamel, in office bleaching techniques were used. Bleaching products used were: two of domestic origin - Lase Peroxide Sensy (LPS 35) and Lase Peroxide Sensy II (LPS 25); and two foreign origin - Opalescence Xtra Boost (OXB 38) and Opalescence Quick (Q 35) and the following protocols were followed for all bleaching products: 1 - no application (control); 2 - application following the manufacturer\'s guidelines (Application Normal- N); 3 - Applying for a longer time (Exaggerated Application-E). The application of the whitening gel by increasing the number of applications of the products, thus increasing the contact time of the product on the samples. Excessive application aimed to evaluate the effect of secondary bleaching, resistance to abrasive microdesgaste. The wear coefficient (Ks) is inversely proportional to the resistance microdesgaste. Results: Analysis of variance showed that the wear coefficients (Ks) groups showed normal distribution, which allowed the application of the Tukey test, which ranked groups with similar performance as the microdesgaste. The difference between groups was significant * (p = 0.021). The lowest Ks presented by the groups was for the control group (1.21 E-11). The Q 35 E, 25 E LPS, LPS 35 E, 35 N LPS, LPS 25 N, 38 E OXB, groups are equivalent to each other, and when compared to control. Groups OXB 38 N and 35 N OQ, showed no significant differences, but are not equivalent to the control. * (P <0.05). Conclusion: From these results, the technique of tooth whitening in office when performed according to the manufacturer\'s instructions, does not harm the bovine enamel in terms of resistance to abrasive microdesgaste.

The aim of this study was to evaluate the integrity of the external hexagon of Internal Torque implants (IT Neodent Implante Osteointegrável), that despite of the external hexagon it uses internal hexagon to receive torque during surgical placement, comparing with external hexagon implants: conventional (External Hexagon, EH - Neodent Implante Osteointegrável) and Brånemark System MK III (Nobel Biocare, NO). Moreover, it was validated an analytical model of rotational freedom with experimental measurements. A device was made to measure rotational freedom angles between hexagons of implant and abutment for 10 intact samples of each group and after simulating surgical placement under torques of 45, 60 and 80 Ncm. The distance between the sides of the abutments internal hexagon had been measured for, together with the values of experimental rotational freedom, using the analytical model, with the aid of the program MATLAB. By means of this model it was possible to get the distances between the sides of the external hexagon of implants and thus to guide the measures in mono ocular optical microscope. Also, the distance between vertexes of the external hexagon were obtained for all intact samples. Again, the analytical model was used to get theoretical rotational freedom, in order to validate it. This sequence was repeated after each torque applied. Rotational freedom data were subjected to analysis of variance test (P<.05) showing no significant difference for the angles of intact EH and IT implants: EH 3.31±0.41° and IT 3.30±0.17°; and after 45 Ncm torque: EH 3.27±0.38° and IT 3.31±0.22°. Both were different from intact NO implants: 2.58±0.35°; and after 45 Ncm torque: 2.62±0.35°, that presented the lesser values. However, after 60 Ncm torque there were significant difference between the three types of implants: NO 2.67±0.34°, IT 3.40±0.20° and EH 4.03±0.54°. After 80 Ncm torque, there were significant difference between NO and IT implants, and the averages were 2.63±0.34° and 3.39±0.38°, respectively. The EH implants did not support this torque, deforming the external hexagon. The data of the distances between vertexes of the external hexagon were subjected to Mann-Whitney U test (P<.05) showing no significant difference for intact EH and IT implants, but both were different from NO implants, that presented the lesser values. After the torque of 60 Ncm, EH, IT and NO implants had presented equal statistical results. After the torque of 80 Ncm, IT and NO implants had not presented significant difference, but when comparing to EH implants both had presented difference, with EH implants presenting the lesser values. It could be concluded that IT and NO implants reacted better than EH implant after 60 and 80 Ncm torques in relation to the rotational freedom values. And still, the analytical model used in program MATLAB is valid to determine the theoretical rotational freedom angle of each sample after different levels of torque applied, without the need to realize measurements of rotational freedom in experimental device, being enough to get the distances between the sides of the hexagons of abutment and implants.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

The aim of this study was to test the hypothesis that the endodontic cement composition and the period taken between root obturation and glass fiber post cementation may interfere with bond strength on root dentin. Sixty roots of bovine incisors were instrumented and randomly assigned to 5 groups (N=12): 1, (CI), without obturation, control; 2, (SI) obturation calcium hydroxide based cement (Sealer 26) and immediate post fixation; 3, (S7) obturation with calcium hydroxide based cement and post fixation after 7 days; 4, (EI) obturation zinc oxide-eugenol based cement (Endofill) and immediate post fixation, and 5, obturation with zinc oxide-eugenol based cement and post fixation after 7 days. Glass fiber posts were cemented with a three step adhesive system (Scotchbond Multi-Purpose) and dual resinous cement (Rely- X ARC). In each group, ten roots were transversally sectioned resulting in two 1mm-thick discs on each dental third, cervical (TC), medium (TM) and apical (TA), which were submitted to the micropush-out test with a crosshead speed of 0.5mm/minute. The remaining two roots were prepared for scanning electron microscope observation. Adhesive bond strength data in MPa were submitted to analysis of variance (ANOVA) following Tukey and Dunnett tests (p<0.05): CITC: 6.8±1.5; TM: 5.4±1.9; TA: 4.4± 1.8; SI- TC: 5.2±1.6; TM: 5.0±2.0; TA: 4.1±2.2; S7- TC: 6.9±2.0; TM: 5.4±1.8; TA: 4.5±1.6; EI-TC: 3.5±0.8; TM: 2.2± 0.5; TA: 1.4±0.7; E7- TC: 6.6±1.7; TM: 4.4±1.4; TA: 2.4±0.6. Obturation with a zinc oxide-eugenol cement negatively influenced adhesion to root dentin in all its extension when post was immediately cemented, and just in the apical third was post when cemented after 7 days. The adhesive bond strength was increasingly lower in the direction crow-root for all groups.