Thesis (M.S.)--University of Michigan, 1976.

Thesis (M.S.)--The University of Michigan, 1976.

Orientador: Osvaldo Magro Filho / Banca: Élio Hitoshi Shinohara / Banca: Celso Koogi Sonoda / Resumo: A hemorragia após extração dental constitui-se em uma das complicações mais freqüentes na prática da cirurgia oral. Devido à dificuldade para se exercer manobras como pinçamentos e ligaduras de vasos neste tipo de hemorragias, existe a possibilidade do preenchimento do alvéolo com materiais hemostáticos de ação tópica. O propósito deste estudo foi analisar a influência de três hemostáticos tópicos (Hemostop®, Pro Tape® e ViscoStat®) na cronologia do processo de reparo em feridas de extração dental por meio de uma análise histológica e histométrica. Para tanto foram utilizados 60 ratos (Wistar) machos divididos em quatro grupos de 15 animais cada. Todos os animais foram submetidos à extração do incisivo central superior direito, seguido ou não da colocação de agente hemostático entre o terço médio e apical do alvéolo dental, e posterior sutura com fio reabsorvível. Em grupos de cinco, os animais foram sacrificados aos 7, 14 e 28 dias pós-operatórios por inalação excessiva de éter sulfúrico. Suas maxilas foram separadas, fixadas em formalina, descalcificadas em EDTA e incluídas em parafina. Foram realizados cortes de 6 æm de espessura e corados com Hematoxilina e Eosina, e Tricrômio de Masson. Após a análise histológica, em microscópio óptico; e histometria óssea, com o software ImageLab, os resultados foram submetidos ao teste não-paramétrico de Kruskal-Wallis. Pela metodologia aplicada foi possível concluir que: 1) houve atraso na cronologia do processo de reparo alveolar em todos os grupos tratados; 2) os materiais analisados provocaram intensa reação inflamatória no tecido adjacente; 3) em todos os períodos estudados (7, 14 e 28 dias), a análise histométrica revelou maior neoformação óssea nos animais do grupo 1 (controle). No entanto, a análise estatística constatou diferença significante (p<0,05) somente no 70 dia,...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The hemorrhage after dental extraction is one of the most frequent complications in practice of the oral surgery. Due to the difficulty to exercise maneuvers as arrestty and ligature of blood vessel in this type of hemorrhages, exists the possibility of the filling of the alveolus with hemostatics materials of topical action. The purpose of this study was to analyze the influence of three topical hemostatics (Hemostop®, Pro Tape® and ViscoStat®) in the chronology of the repair process in wounds of dental extraction through a histologic and histometric analysis. For such, 60 male's rats (Wistar) were used divided in four groups of 15 animals each. All the animals were submitted to the extraction of the right superior central incisor, followed or not of the placement of hemostatics agent among the medium and apical third of the dental alveolus, and subsequent suture with reabsorble filament. In groups of five, the animals were sacrificed to the 7, 14 and 28 postoperative days by excessive inhalation of sulfuric ether. Your maxillaries were separate, fixed in formalin solution, decalcified in EDTA and included in paraffin. Cuts of 6 æm of thickness were accomplished and stained with hematoxylin and eosin, and Masson's trichromic. After the histologic analysis, in optical microscope; and histometric bony, with the software ImageLab, the results were submitted to the no-parametric test of Kruskal-Wallis. For the applied methodology it was possible conclude that: 1) there was delay in the chronology of the alveolar repair process in all the treated groups; 2) the analyzed materials instigated a intense inflammatory reaction in the adjacent tissue; 3) in all the studied periods (7, 14 and 28 days), the histometric analysis revealed larger bony neoformation in the animals of the group 1 (control group)...(Complete abstract click electronic access below) / Mestre

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Thesis (M.S.)--University of Michigan, 1962.

Thesis (M.S.)--University of Michigan, 1962.

Resumo: Objetivos: Avaliar a interferência da ovariectomia (OVX) e seu tratamento com estrógeno (E2) ou com raloxifeno (RLX) no balanço entre RANKL/OPG na cronologia do processo de reparo alveolar em diferentes períodos (7, 14, 21 e 42 dias) através da imunofluorescência por co-localização e análise histomorfométrica. Materiais e Métodos: Os grupos estudados foram: sham, OVX, OVX+E2, OVX+RLX. Após obtenção dos cortes histológicos corados em hematoxilina e eosina e as reações de co-localização por imunofluorescência de RANKL/OPG, os resultados foram avaliados quantitativamente. Resultados:Aos 7 dias: menor neoformação de trabéculas ósseas,o grupo OVX+RLX apresentou menor valor médio. O grupo OVX apresentou o maior turnover ósseo representado pelas co-localizações de OPG e RANKL. Aos 14 dias o grupo OVX+RLX apresentou menor formação óssea. O grupo sham apresentou intensa atividade celular representada pela alta imunorreatividade à OPG e RANKL observada nas células. Aos 21 dias os grupos experimentais apresentaram maiores níveis de ossificação; não apresentaram diferença estatística. O grupo OVX apresentou o menor turnover ósseo. Aos 42 dias houve diferença estatística na quantidade de formação óssea entre o grupo sham comparado aos demais grupos (p<0,05) e o grupo OVX apresentou o maior turnover ósseo. Conclusão: A ovariectomia atrasou o processo de reparo alveolar e alterou o turnover ósseo. A reposição do estrógeno e o tratamento com raloxifeno melhoraram as respostas, mas não restabeleceram completamente os valores da histometria e da colocalização do grupo sham. / Abstract: Objectives: To evaluate the influence of the ovariectomy (OVX), and its treatments with estrogen (E2) or with raloxifene (RLX) on the RANKL/OPG balance during the periods in the chronology of the alveolar wound healing process (7, 14, 21 end 42 pos operative days) in female rats by means of immunocolocalization and histomorphometric analysis. Methods: The studied groups were: sham, OVX, OVX with E2 replacement, OVX with (RLX) treatment. After obtaining the histological tissue pieces colored in hematoxilin and eosin and the immunocolocalization reaction for RANKL and OPG, the results were quantitatively evaluated. Results: At 7 days, was observed lesser neoformed trabeculae bone, the smaller medium value was observed to the OVX+RLX group. The OPG and RANKL immunocolocalization showed larger bone tunover to OVX group. At 14 days there was a larger quantity of neoformed trabeculae bone, the smaller medium value was observed to the OVX+RLX group, the sham group presented an intense cellular activity. At 21 days the experimental groups had a greater ossification levels; no statistical significance was observed. The OVX group had the lowest bone turnover. At 42 days there were statistically differences on the quantity of ossification within sham group compared to the other groups (p<0.05). The OVX group showed the largest bone turnover. Conclusions: Ovariectomy delays the alveolar wound healing process and interferes with the bone turnover. The E2 replacement and the RLX treatment improved the healing but not enough to reach histomorphometric and immunocolocalization valours of the sham group. / Orientador: Roberta Okamoto / Coorientador: Rita Cássia Menegati Dornelles / Banca: Wilson roberto Poi / Banca: Teresa Lucia Lamano Carvalho / Mestre