Orientador: Rafael Leonardo Xediek Consani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-19T18:58:43Z (GMT). No. of bitstreams: 1 Pereira_IzabellaPatta_M.pdf: 232201720 bytes, checksum: 0b2b26f92aef735008aedcbf80bf148a (MD5) Previous issue date: 2012 / Resumo: O objetivo neste estudo experimental in vitro foi avaliar o comportamento das tensões induzidas nas estruturas de suporte de prótese total, por meio da análise fotoelástica nas seguintes condições: Grupo 1- prótese total convencional, Grupo 2- prótese total convencional reembasada com material rígido permanente à base de resina acrílica e Grupo 3- prótese total convencional reembasada com material resiliente permanente à base de silicone. Para este experimento foram confeccionadas três próteses totais inferiores e uma prótese total superior, possibilitando que os testes fotoelásticos fossem conduzidos com as próteses em posição de máxima intercuspidação habitual. Foram feitos carregamentos axiais no modelo fotoelástico mandibular com cargas de 10, 20 e 30 kgf /cm! em cada corpo-deprova. O Grupo 1 apresentou tensões em toda extensão do rebordo, com maior ênfase na região anterior e lateral esquerda e menor tensão na lateral direita. Na região lateral esquerda, o Grupo 2 apresentou tensões similares ao Grupo 1 nas regiões de pré-molares e trígono retromolar. O Grupo 3 exibiu diminuição das ordens de franja e distribuição homogênea de tensões induzidas. Concluiu-se que prótese total convencional e a prótese total convencional reembasada com material à base de resina acrílica geraram tensões pontuais, podendo acarretar maior reabsorção do tecido ósseo. Já o material reembasador à base de silicone proporcionou distribuição mais homogênea das tensões induzidas pela prótese / Abstract: The aim of this experimental in vitro study was to evaluate the behavior of the stresses induced in the supporting structures of denture through the photoelastic method in the following conditions: Group 1- conventional denture, Group 2- conventional denture relined with hard chairside reline resin and Group 3- conventional denture relined with resilient material silicone-based. For this experiment were made three lower dentures and a maxillary one. The photoelastic tests were conducted with the prosthesis in position of maximum intercuspation. Loads were made in axial position. The mandibular photoelastic model was loaded with 10, 20 and 30 kgf/cm! in each specimen. The Group 1 showed stresses all along the model, with greater emphasis on the anterior and left lateral and less strain on the right side. In the left lateral surface, Group 2 showed similar as Group 1, with stresses in the region of premolar and retromolar trigone. The Group 3 exhibited decreased of fringe orders and homogeneous distribution of induced stresses. It was concluded that the first and the second groups generated punctual tensions, which may cause increased bone resorption. The relining material based on silicone provided more homogeneous distribution of the stresses induced by the prosthesis / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Il a été récemment montré que la vasorine (Vasn), d’abord décrite comme une protéine membranaire de type I qui neutralise TGFb, était exprimée par les ostéocytes et les ostéoblastes et impliquée dans le métabolisme du phosphate et du calcium. L’analyse MicroCT a montré que des souris Vasn -/- présentaient des signes de rachitisme avec des volumes osseux trabéculaires et corticaux fortement réduits. Ici, nous explorons pour la première fois l’expression et les fonctions de Vasn dans le territoire craniofacial. Nous démontrons que 1) Vasn est exprimée au sein de la dent en formation par les odontoblastes et les cémentoblastes et dans l’os alvéolaire par les ostéoblastes et les ostéocytes, 2) des souris Vasn -/- présentent un phénotype dentaire mixte associant des signes de rachitisme tels qu’une croissance réduite du squelette, une dentine minéralisée moins épaisse, des chambres pulpaires élargies et des signes supplémentaires évoquant une hypophosphatasie , principalement une formation perturbée de la racine avec des canaux dentaires élargis. Toutes ces données suggèrent un rôle important de Vasn dans la minéralisation de l’os et de la dent, probablement en régulant le dépôt de matrice et son organisation, plutôt que le processus de minéralisation lui-même. / Vasorin (Vasn), first described as a type I membrane protein which neutralizes TGFβ, has been recently shown to be expressed by osteocytes and osteoblasts and involved in the phosphate and calcium metabolism. MicroCT analysis have indicated that Vasn -/- mice displayed signs of rickets with dramatically reduced trabecular and cortical bone volumes. Here, we explored for the first time Vasn expression and function in the craniofacial area. We demonstrated that 1) Vasn is expressed in the forming tooth by odontoblasts and cementoblasts and in the alveolar bone by osteoblasts and osteocytes, 2) Vasn-/- mice present a mix cranial and dental phenotype associating signs of rickets such as, reduced skull growth, reduced thickness of mineralized dentin, and enlarged pulp chambers, and additional signs evokating hypophosphatasia, namely disturbed root formation with enlarged root canals. All these data suggest an important role of Vasn in bone and tooth mineralization, probably by regulating matrix deposition and organization rather than the mineralisation process itself.

L' étude réalisée s'est portée sur la détermination de l’âge à partir d’investigations sur l’alvéolyse humaine.Le manque de fiabilité de l’attache épithéliale comme indicateur d’âge et l’absence de corrélation de la translucidité dentinaire sur dents entières ou coupées ont démontré l'intérêt d'un nouveau modèle odontologique d'estimation de l'âge. Nous avons, pour cela, , recruté une série importante de scanners (500)à visée implantaire assortis d’un questionnaire médico-administratif administré en face à face. Une base équilibrée en terme de sex-ratio et de classes d’âge a été constituée avec comme critère d’inclusion des secteurs dentés et observables. La deuxième phase a consisté à pratiquer des mesures biométriques de la hauteur de perte d’os alvéolaire par rapport au référent classique que constitue la jonction émail Cément. A partir des données relevées, et ajustées sur les variables individuelles et comportementales recueillies dans le questionnaire, nous avons établi une corrélation avec la variable continue, l’âge. Nous avons pu proposer un modèle d’estimation de l’âge alternatif à celui de la méthode odontologique de Lamendin avec une fiabilité identique mais applicable sur des classes d’âges de 25 à 60 ans.Cette méthode a été validée par une étude comparative de trois indicateurs d'erreurs et la formule optimisée par la méthode Bootstrap. Les modèles ont été, ensuite, appliqués sur une série de crânes anciens complets (32) et sur une population contemporaine (50). Enfin, nous avons ouvert la perspective ,à partir du même protocole, d'estimation de l'alvéolyse à partir de l'âge ajusté ou non sur les différentes variables retenues dans l'étude principale. / The study carried out concerned to the determination of the age from investigations on the human alveolar bone loss. The lack of reliability of the tie epithelial as indicator of age and the absence of correlation of the transparency of the dentin on whole or cut teeth demonstrated the interest of a new odontological model of estimation of the age. We have, for it, recruited an important series of scanners (500) for implantological treatment matched by a medical administrative questionnaire administered opposite to face. A base balanced in term of sex-ratio and age groups was established with as criterion of inclusion of the toothed and observable sectors. The second phase consisted in practicing biometric measures of the height of loss of alveolar bone with regard to the classic referent that the junction enamel Cement establishes .From the data, and adjusted on the individual and behavioral variables collected in the questionnaire, we established a correlation with the continuous variable, the age. We were able to propose a model of estimation of the age in that of the odontological method of Lamendin with an identical but applicable reliability on age groups from 25 to 60 years. This method was validated by a comparative study of three indicators of errors and the formula optimized by the Bootstrap method. The models were, then, applied to a series of ancient complete skulls (32) and to a contemporary population (50). Finally, we opened the prospect, from the same protocol, from the estimation of the alveolar bone loss from the adjusted age or not on the various variables held) in the main study.

Magister Scientiae Dentium - MSc(Dent) / Autologous bone grafting in conjunction with dental implant therapy is a well-accepted procedure in oral and maxillofacial rehabilitation. A variety of intraoral donor sites, such as the mandibular symphysis, the mandibular ramus and the maxillary tuberosity have been used in oral and maxillofacial reconstruction. However these sites are associated with complications. In order to reduce these complications, the anterior palate has been proposed as a potential donor site. However, the scientific literature in this regard is sparse, and larger studies are required to investigate the clinical potential of this proposed site. Aim: To determine the volume and density of available bone in the anterior palate that may be used for bone harvesting using cone-beam computed tomography (CBCT) in a select South African population. Materials and methods: One hundred previously acquired CBCT scans taken at the Diagnostic and Radiology Department of Tygerberg Oral Health Centre were analyzed for the required data. These were all acquired from a single CBCT machine (Newtom VGI®, Verona, Italy). The study sample included 52 females and 48 males ranging from ages 20 years to 80 years. The CBCT scans were divided into 3 different age groups. The first age group was between the ages of 20 and 39 years, the second age group was from 40 to 59 years and the third age group was ≥ 60 years. The volume and density of the anterior palate of the different age groups were analyzed using specific criterion. CBCT specific software (Simplant Pro Crystal®) Dentsply implants, Mannheim, Germany was used to standardize the data collection. All data was stored in a Microsoft Excel spreadsheet (Microsoft Corporation, Washington, USA). Results: The mean volume of the anterior palate in this study was 2.11 ± 0.55 cm3, with a minimum volume of 1.04 cm3 and a maximum volume of 3.82 cm3. There was no significant difference in the volume and density of the anterior palate between different age groups and no significant difference in the volume between males and females (p value = 0.227). Conclusions: The anterior palate affords a considerable amount of bone volume which is similar or even more than other intraoral donor sites. The anterior palate is a potential donor site for bone harvesting and CBCT may be regarded as an ideal tool to analyze the amount of bone available for harvesting.

Objetivos: Avaliar o efeito da inibição de triptase, com o uso da droga nafamostate mesilate (NM), sobre o desenvolvimento de doença periodontal induzida em ratos. Metodologia: Oitenta ratos Wistar machos foram divididos aleatoriamente em quatro grupos. Um grupo controle com injeção diária de NaCl 0,9%, grupo NM (injeção diária de 0.1mg/kg de NM, ip), grupo ligadura (colocada ao redor do primeiro molar inferior direito), e grupo NM + Ligadura. A quantidade de perda óssea alveolar (POA) na porção mesial da face lingual da raiz mésio-lingual do primeiro molar inferior foi determinada após o sacrifício aos sete e 14 dias com o auxílio de um estereomicroscópio, e a atividade de mieloperoxidase (MPO) foi analisada nos tecidos gengivais. Resultados: A inibição da triptase levou à diminuição significativa (p <0,05) de POA em animais submetidos à ligadura e periodontite induzida. A inibição da triptase pelo NM não apenas preveniu o início da POA aos sete dias de experimento (0,44mm 0,16 e 0,60mm 0,22, p<0,05, NM + Ligadura versus Controle), como também diminuiu significativamente a POA aos 14 dias (0,97mm 0,17 versus 1,82mm 0,26, p <0,001, NM + Ligadura versus Ligadura). Além disso, a inibição da triptase diminuiu significativamente a atividade de MPO aos 14 dias (p<0.05). Conclusão: Os dados do presente estudo sugerem que a inibição da triptase modificou a progressão da periodontite induzida experimentalmente em ratos. / Aim: To evaluate the effect of inhibition of tryptase, with the drug nafamostate mesylate (NM) on the development of periodontal disease induced in rats. Methodology: Eighty (80) male Wistar rats were randomly separated into four study groups as follows: saline Control group, NM group (daily injection of 0.1mg/kg body weight of NM, i.p.), Ligature group (ligature placed at the gingival margin level of lower right first molars), and NM + Ligature group. The amount of alveolar bone loss (ABL) around the mesial root surface of the first mandibulary molar was determined at sacrifice at seven and 14 days with the aid of a stereomicroscope, and the myeloperoxidase activity (MPO) was analyzed at the gingival tissues. Results: NM led to significantly (p<0.05) decreased ABL in animals subjected to ligature induced periodontitis. Tryptase inhibition not only prevented the onset of significant ABL at seven days of the experiment (0.440.16 and 0.600.22, p>0.05, NM+Ligature and Control, respectively) but also significantly decreased the ABL when compared with the Ligature group at 14 days (0.970.17 versus 1.820.26, p<0.001). In addition, NM significantly decreased MPO activity at 14 days (p<0.05). Conclusion: These data provide evidence that tryptase inhibition may modify the progression of experimentally induced periodontitis in rats.

No description available.

No description available.

No description available.

No description available.

AIM: To evaluate marginal bone loss around dental implants at the 2nd stage abutment surgery and retrospectively evaluate the association of pre-surgical variables. MATERIAL AND METHODS: Eighty-seven subjects (41 Males and 46 females) were enrolled in this cohort. The subjects' ages ranged from 23 to 80 years. Two endosseous implant brands were utilized: Nobel Biocare and Straumann Bone Level . Clinical measurements (mesial, distal, buccal, and lingual) were recorded from the coronal margin of the implant platform to the bone margin with a periodontal probe (Williams periodontal probe, Hu-Friedy) at the time of implant placement and at the 2nd stage abutment surgery. The pre-surgical variables (medication intake, implant site, bone graft volume, membrane type, and smoking) were evaluated using Chi-square test. RESULTS: The marginal bone loss (MBL) difference was calculated. The Mean clinical MBL: Mesial = 0.71 mm, Distal = 0.56mm, Buccal/Labial = 0.65 mm, and Lingual/Palatal = 0.56 mm. The test showed no statistically significant difference between test and control subjects in each of the variables, with the exception of thyroid medication. A statistically significant (P value = 0.011) association was found between levothyroxine and MBL at the mesial measurement. CONCLUSION: This limited cohort study suggests that medication-controlled hypothyroidism patients may experience an increased risk of marginal alveolar bone loss around dental implants at the 2nd stage abutment surgery. The final determination will be recalculated when the study population reaches the estimated requirement of 200 subjects.