Avaliação da eficiência da técnica de obturação pela compressão hidrùlica vertical após instrumentação automatizada

The purpose of this study was to evaluate through radiographic and microscopic analysis the efficiency of the filling techniques by vertical hidraulic compression after the root canal mechanical instrumentation in vitro as well to evaluate the marginal apical leakage through macroscopic and microscopic analysis. Thirty human mandibular molars were used , they were divided on three groups, these were subdivided on six subgroups with five specimens each, come down to 106 root canals filled. Initially, the teeth were instrumented with Profile system series 29 and filled with two ways: single accessory cone or single cone associated with gutta-percha secundary cone, with Fill Canal sealer or Sealer 26. Completed the filling, the teeth were coated with araldit and finger -nail polish except for the apical 2 mm and dried for 3 hours, thep radiographs were taken of the teeth in orto and disto-radiai directions. Next, the coronal seal was carried out with composite resin photopolymerized and with their process of making impermeable. Teeth of positive controls were used without araldit and finger-nail polish whereas the negative controls were used with total coat of araldit and finger-nail polish. The specimens were placed in 2% Methylene Blue dye for 24 hours and thermocycled for 7 days. Afterwards, sections were made of each tooth at mesial and distal roat, after this the teeth were radiographed at buccolíngual direction for a macroscopic analysis and at buccolingual and mesiodistal directions for assessment of the marginal apical leakage. Cross sections were made 3 mm to 3mm since the tooth apice. The sections obtained for each group were observed with a stereomicroscope to evaluate the quality of the root canal filling and the marginal apical leakage. The results showed that: In the four techniques the marginal dye leakage was present in the apical third; in all groups the quality of the root canal filling in the radiography was better at mesial root canal and the single cone technique showed inefficient when only a single distal root canal was present. In the radiographic evaluation the best quality of the root canal filling was observed in the 1A group (single accessory cone + FiIl Canal), as in the mesial root as in the distal root wich Shcwed twe root canals: when the distaI root had only one canal. the best result was showed by 28 group (single accessory cone associated with secundary cone + Fill Canal) In the macroscopic analysis of longitudinal !eaKage (outside surface). less leakage was showed as In the mesial root as in the distal root in the negative control group (3) followed 2A group (single accessory cone + Sealer 26). When the microscopic analysis of tranversal leakage of both roots (inside surface) was carried out. the groups that showed less dye leakage were the negative control (38) followed the 28 group (single acessory cone associated with secundary cone + Sealer 26). The homogeneity o filling was best noted in the 1 A group (.single accessoty cone + Fill Canal). The groups that showed less dye penetration in the tranversal leakage (total area) were negative control (3B) and 2B

Análises clínicas, radiográfica e microscópica de molares permanentes sem ou com lesão de cárie na superfície oclusal

O presente trabalho, objetivou avaliar comparativamente o diagnóstico clínico, radiógráfico e histológico de molares permanentes humanos sem ou com lesão de cárie na superfície oclusa!. Vinte e quatro dentes que estavam armazenados em formalina a 10% foram selecionados e em seguida submetidos a um exame clínico, através da inspeção visual, onde foram separados em 3 grupos: grupo 1 (G1), formado por dentes hígidos; grupo 2(G2), por dentes com pigmento na superfície oclusal e grupo 3(G3), aqueles com lesão de cárie na oclusal. Este exame foi realizado com auxílio de luz artificial proveniente de um refletor odontológico, sem qualquer manipulação da superfície. Para cada dente foram realizados duas tomadas radiográficas com e sem tela milimetrada, no sentido vestibulo lingual por um dos avaliadores, simulando uma radiografia interproximal, onde o feixe incidiu perpendicular ao longo eixo do dente. Em seguida os dentes foram preparados histomorfologicamente para coloração com hematoxilina e eosina e análise microscópica. Pela avaliação dos resultados a partir da amostra de 100%, foi possível concluir: 1) Os dentes clinicamente considerados hígidos (G1) apresentaram radiograficamente 74,99% de ausência de imagem radiolúcida e em 25% presença desta imagem na Junção Amelo¬dentinária e microscopicamente ausência de cárie em 100%; 2) os dentes que clinicamente apresentaram fissura pigmentada' (G2) notou-se em 33,33%, ausência da imagem radiolúcida e em 66,66% presente esta imagem na junção amelodentinária, 100% de ausência de cárie através da análise microscópica; 3) clinicamente, os dentes que apresentaram lesão de cárie (G3), radiograficamente foram comprovados 100% de imagem radiolúcida sugestiva de cárie e microscopicamente dos 100% destas, foram considerados cáries rasa (16,66%), média (61,10%) e profunda (22,22%) respectivamente

Genotoxicity of corrosion eluates obtained from orthodontic brackets in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hypertrophy and neuron loss: structural changes in sheep SCG induced by unilateral sympathectomy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Celecoxib treatment does not alter recruitment and activation of osteoclasts in the initial phase of experimental tooth movement

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Periodontal tissue response to coverage of root cavities restored with resin materials: A histomorphometric study in dogs

Background: the purpose of this study was to histomorphometrically evaluate the response of periodontal tissues covering Class V resin restorations in dogs.Methods: After raising a mucoperiosteal flap, bony defects measuring 5 x 5 mm were created on the buccal aspect of the canines of five dogs followed by cavity preparations on the root surface measuring 3 x 3 x 1 mm. Before repositioning the flap to cover the bone defect, the cavities were restored with composite resin (CR) or resin-modified glass ionomer cement (RMGIC) or were left unrestored as control (C). The dogs were euthanized 90 days after surgery. Specimens comprising the tooth and periodontal tissues were removed, processed routinely, cut into longitudinal serial sections in the bucco-lingual direction, and stained with hematoxylin and eosin (H&E) or Masson's trichrome. The most central sections were selected for histomorphometric analysis.Results: Histomorphometric analysis revealed apical migration of epithelial tissue onto the restorative materials (RMGIC and CR). The C group presented significantly longer connective tissue attachment (P < 0.05) than the RMGIC and CR groups and significantly higher bone regeneration (P < 0.05) compared to the RMGIC group. Histologically, the cervical third (CT) of all groups had the most marked chronic inflammatory infiltrate.Conclusions: Within the limits of this study, it can be concluded that the restorative materials used exhibit biocompatibility; however, both materials interfered with the development of new bone and the connective tissue attachment process.

Effect of calcium hydroxide-based materials on periapical tissue healing and orthodontic root resorption of endodontically treated teeth in dogs

This study evaluated periapical tissue healing and orthodontic root resorption of endodontically treated teeth sealed with calcium hydroxide in dogs. The sample consisted of three contralateral pairs of maxillary incisors and two contralateral pairs of mandibular incisors in each of two dogs using a split mouth design. After biomechanical preparation of the teeth in the first group (n = 10), a Ca(OH)(2) dressing was placed for 14 days before root canal filling with Ca(OH)(2)-based sealer (Sealapex) and gutta-percha points. In the second group (n = 10), root canals were obturated immediately after the mechanical preparation with gutta-percha points and zinc oxide and eugenol (ZOE)-based sealer (Endofill). After completion of endodontic treatment, the teeth were moved with an orthodontic appliance with a calibrated force of 200 g, reactivated every 21 days. After 105 days, the animals were killed and the teeth were removed upon completion of active treatment, without a period of recovery, and prepared for histomorphological analysis. All sections of each tooth were graded subjectively on a scale from one to four to obtain the average of the 16 histomorphological parameters analysed. Evaluation of the differences between the two treatment protocols was made with Mann-Whitney U-test. It was observed that the teeth treated with Ca(OH)(2)-based materials provided better outcomes (P = 5%), with complete repair of all root resorption areas, high rate of biological closure of the main canal and apical accessory canals by newly formed cementum, less intense and extensive chronic inflammatory infiltrate, and better organization of the periodontal ligament. Under the tested conditions, Ca(OH)(2)-based materials had a favourable action on periapical tissue healing and repair of orthodontic root resorption in endodontically treated dogs' teeth.

Histometric analysis of ligature-induced periodontitis in rats: a comparison of histological section planes

The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats at different histological section depths. Sixteen male adult Wistar rats were randomly assigned to two groups: ligature and control. In the ligature group, rats received a sterile 4/0 silk ligature around the maxillary right 2nd molar. Thirty serial sections containing the 1st and 2nd molars, in which the coronal and root pulp, cementoenamel junction (CEJ) in the mesial side of the 2nd molar, interproximal alveolar bone and connective fiber attachment were clearly visible, were selected for histometric analysis. The histological sections were clustered in groups of 10 sections corresponding the buccal (B), central (C) and lingual (L) regions of the of periodontal tissue samples. The distance between the CEJ in the mesial side of the 2nd molar and the attached periodontal ligament fibers (CEJ-PL) as well as the distance between the CEJ and the alveolar bone crest (CEJ-BC) were determined. From CEJ-PL and CEJ-BC distances measured for each specimen, the measurements obtained in the B, L and C regions were recorded individually and together. Data were submitted to statistical analysis. Significant differences (p<0.001) were observed between the control and ligature groups regarding CEJ-PL (0.05 mm and 0.26 mm, respectively) and CEJ-BC (0.47 mm and 0.77 mm, respectively) measurements. Regarding the depth of the buccal, central and lingual planes, the means of CEJ-PL and CEJ-BC of both groups showed no statistically significant differences (p>0.05). In conclusion, the selection of 10 serial sections of the central region of periodontal tissue samples at any depth can be considered as representative for the evaluation of periodontal ligament fiber attachment and bone loss in ligature-induced periodontitis in rats.

Mechanics of the maxillary central incisor. Influence of the periodontal ligament represented by beam elements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Crown Ferrule Heights and Dowel Material Selection on the Mechanical Behavior of Root-Filled Teeth: A Finite Element Analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prevalence of removable partial dentures users treated at the Aracatuba Dental School - UNESP

Objectives: The aim of this study was to evaluate the frequency of removable partial dentures (RPD) at the Aracatuba Dental School.Methods: The study was conducted by analysing 412 clinical history of patients attended at the RPD clinics in the period from 2000 to 2007.Results: 412 charts were analysed: 148 (35.9%) men and 264 (64.1%) women. The mean age was 53.8 years (men) and 52.4 years (women). A total of 556 dentures were made; of these, 233 (41.90%) were maxillary and 323 (58.09%) were mandibular dentures. The most frequent Kennedy classification found was Class III (maxilla) and Class I (mandible). In the maxilla, 55% (126) of the major connectors were of the anterior-posterior palatal bar, while in the mandible, 64% (202) were the lingual bar. As regards the claps, 401 were circumferential and 318 were bar claps.Conclusion: The mean age of the patients was 52.9 years with higher prevalence of female patients; the most frequent Kennedy's classification was Class I in mandible and Class III in maxilla; the most common major connector was anterior-posterior palatal bar for maxilla and lingual bar for mandible; the circumferential clasps were the most common retainer used in both jaws.

Mechanical behavior of ceramic veneer in zirconia-based restorations: a 3-dimensional finite element analysis using microcomputed tomography data

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of customized composite resin fibreglass posts on the mechanics of restored treated teeth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biomechanical evaluation of internal and external hexagon platform switched implant-abutment connections: An in vitro laboratory and three-dimensional finite element analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cortical Bone Stress Distribution in Mandibles with Different Configurations Restored with Prefabricated Bar-Prosthesis Protocol: A Three-Dimensional Finite-Element Analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)