Oxygen Saturation in the Dental Pulp of Maxillary and Mandibular Molars - Part 2

Abstract This study determined the oxygen saturation (SaO2) in dental pulp of healthy maxillary and mandibular molars. Mean of SaO2 was evaluated in 112 maxillary and mandibular molars using pulse oximetry. Quantitative variables were described by mean and standard deviation. Variables with symmetric distribution were compared by Student t test and Mann-Whitney test. Pearson's correlation coefficient was used to correlate quantitative variables. Analysis of variance was used to assess differences in SaO2 levels between the molar groups, followed by post-hoc Tukey. The significance level established at p<0.05. Mean of oxygen saturation for the 112 molar dental pulps was 85.09%. There was no significant correlation (r=-0.007; p=0.977) between the mean of SaO2 of molar pulps with patient´s indicator finger (92.89%). There was a significant difference (p=0.037) between the mean of SaO2 of the first (85.76%) and second maxillary molars (81.87%), and it was not significant (p=0.1775) between the first and second mandibular molars. Maxillary molars had lower pulpal SaO2 (83.59%) than mandibular molars (86.89%) (p=0.018). The mean of the patient's response time to the cold stimulus was 1.12 s (maxillary molars 1.25 s and mandibular molars 0.99 s)(p=0.052). There was no significant correlation between the time response of the patient to the cold stimulus and the SaO2 for molars. The mean oxygen saturation level was 85.09%. The mandibular molars presented higher SaO2 level than maxillary molars.

Resumo Este estudo determinou o nível de saturação de oxigênio (SaO2) em polpas dentais hígidas de molares. O nível de SaO2 foi avaliado em 112 molares superiores e inferiores usando oxímetro de pulso. As variáveis quantitativas foram descritas pela média e desvio padrão. As variáveis com distribuição simétrica foram comparadas pelo teste t de Student e teste de Mann-Whitney. O coeficiente de correlação de Pearson foi utilizado para correlacionar variáveis quantitativas. A análise de variância foi utilizada para avaliar as diferenças nos níveis de SaO2 entre os grupos de molares, seguido de Tukey pós-hoc. A significância foi estabelecida em 0,05. O nível médio de SaO2 para as polpas de 112 molares foi de 85,09%, não havendo correlação com a média de SaO2 do dedo indicador do paciente (92,89%). Houve diferença significativa entre o nível médio de SaO2 dos primeiros molares superiores (85,76%) e os segundos molares superiores (81,87%) e não foi significativo entre os primeiros e os segundos molares inferiores. Os molares superiores apresentaram menor nível de SaO2 (83,59%) do que os molares inferiores (86,89%). A média do tempo de resposta do paciente ao estímulo com frio foi de 1,12 s (molares superiores 1,25 segundos e molares inferiores 0,99 segundos). Não houve correlação significativa entre o tempo de resposta do paciente ao estímulo com frio e o nível de saturação de oxigênio para os molares. Em resumo, o nível médio de saturação de oxigênio foi de 85,09%. Os molares inferiores apresentaram maior nível de SaO2 do que os molares superiors

Bone healing of mandibular critical-size defects in spontaneously hypertensive rats

Few articles have shown changes in bone metabolism caused by hypertension. The objective of this study was to investigate the relationship between hypertension and bone healing. Circular critical-size defects 5 mm and 2 mm in diameter were created, respectively, on the left and right side of the mandible in 40 spontaneously hypertensive and 40 control Wistar-Kyoto rats. Five animals from each strain were killed 2, 3, 5, 10, 15, 30, 60 and 90 days after surgery. The macroscopic evaluation showed great mandibular angle deformation on the left side and non-healed defects on both sides and groups. Histological evaluation revealed similar bone healing on both sides, with initial necrosis in the central area, and fibrosis and angiogenesis within the first 5 days. From the 10th postoperative day on, the newly formed bone displayed progressive thickening until the 90th postoperative day, when the defect margins presented a compact bone structure. Furthermore, the statistical analysis of the histometric data did not reveal any significant hypertension effect on bone healing in the defect area. These results suggest that bone healing was not different between spontaneously hypertensive rats and control rats.

Use of the plasma CTX for assessing the bone activity of the mandible among osteopenic and osteoporotic patients

The aim of this study was to determine whether the plasma CTX bone remodeling marker is useful for indicating the bone metabolic activity level of the mandible. Thirty-six patients were selected; all were postmenopausal and aged 50 years or over. In accordance with the WHO criteria for osteoporosis, a control group was set up (n = 10) in which the T-score was greater than -1 and a diseased group with T-score less than -1. Using MDP-99mTc samples, the radioisotope uptake in the femoral neck (R2) and mandibular body (R1) was analyzed. A third examination was performed using the plasma CTX biochemical bone-modeling marker. The inferential results for the diseased group showed that Ln(R1) presented a statistically significant linear relationship with Ln(CTx) (p = 0.067) and with the T-score (p = 0.018). The plasma CTX bone remodeling marker is useful for monitoring the bone metabolic activity of the mandible.

Single photon emission computerized tomography in the evaluation of the osteoblastic activities of a new bone regeneration technique: analysis of 12 mandibular sites in six experimental pigs / La tomografía computarizada por emisión de fotón único en la evaluación de las actividades osteoblásticas de una nueva técnica de regeneración ósea: análisis de 12 sitios mandibulares en seis cerdos experimentales

OBJECTIVES: To utilize single photon emission computerized tomography performed in sequence to determine the osseo-integrating capabilities and osteoblastic activities of a new bone regeneration technique called the membrane - sandwich technique (Ogunsalu sandwich bone regenerating technique) and to compare the quality and quantity of bone formed by this bone regeneration unit to bone regeneration obtained by using the same particulate bone grafting material covered with interceed® (another type of bio-resorbable membrane). DESIGN AND METHOD: Single photon emission computerized tomography bone imaging was performed in sequence on the mandible of a total of 6 pigs on both the right and left side (total of 12 sites) at two and a half hours following the injection of technetium 99m methylene diphosphate. Imaging was performed using a Siemen Orbitar II gamma camera. The projection data was acquired in a 128 x 128 matrix over 180 arc and SPECT reconstruction was performed using a filtered back projector method with a Shepp-Logan Hanning filter and a cut-off frequency of 0.4. The surgical defect on one side of the jaw was treated with the sandwich unit with Bio-oss particulate bone within it, while the other side contained the same quantity of Bio-oss as in the left side but just covered with interceed® membrane. The osteoblastic uptake on the side with the classical sandwich was compared to the side with the particulate bone covered with interceed® membrane for dynamic physiological activities. The average activity for both sides was calculated and compared. RESULT: For all the 12 sites, osteoblastic activities were recorded and indicated that vascularized bone was formed at all the experimental sites. Autogenous bone graft was confirmed to be superior to xenograft using this sandwich technique. Furthermore, the osteoblastic activities on the sandwich side were seen to be more when compared with the control side (Interceed® side). CONCLUSION: The Ogunsalu sandwich bone regeneration technique has been successfully evaluated with SPECT which shows osteoblastic activity with formation of vascularized bone which integrates with the surrounding bone.

OBJETIVOS: Utilizar la tomografía computarizada por emisión de fotón único (TCEFU) realizada en secuencia, a fin de determinar la capacidad óseo-integradora y las actividades osteoblásticas de una nueva técnica de regeneración del hueso, denominada técnica de membrana-sándwich, y comparar la calidad y cantidad de hueso formado por esta unidad de regeneración ósea con la regeneración ósea obtenida mediante el mismo material de injerto de hueso particulado cubierto con interceed® (otro tipo de membrana bioreabsorbible). DISEÑO Y MÉTODO: Mediante TCEFU, se realizó un estudio de imágenes óseas en secuencia, de la mandíbula de un total de 6 cerdos, a los lados izquierdo y derecho (un total de 12 sitios) a las dos horas y media, luego de una inyección de difosfato de metileno marcado con tecnecio 99 m. El examen de imágenes fue realizado usando una cámara gamma Siemens Orbiter tipo II. Los datos de la proyección fueron adquiridos en una matriz de 128 x 128 sobre un arco de 180 y la reconstrucción con TCEFU se realizó usando un método de retroproyección filtrada, con un filtro Shepp-Logan-Hanning y una frecuencia de corte de 0.4. El defecto quirúrgico en un lado de la mandíbula fue tratado con la unidad de sándwich con hueso particulado bio-oss dentro, mientras que el otro lado contenía la misma cantidad de Bio-oss del lado izquierdo, pero cubierto con una membrana de interceed®. La respuesta osteoblástica en el lado con el sándwich clásico fue comparada con el lado del hueso particulado cubierto con la membrana de interceed® en cuanto a actividades fisiológicas dinámicas. La actividad promedio de ambos lados fue calculada y comparada. RESULTADO: En los 12 sitios, las actividades osteoblásticas fueron registradas de forma indicando que se formó hueso vascularizado en todos los sitios experimentales. Se confirmó que el injerto óseo autógeno es superior al xenoinjerto que usa esta técnica de sándwich. Además, se observó que las actividades osteoblásticas en el lado del sándwich eran más en comparación con el lado control (lado del interceed®). CONCLUSIÓN: La técnica de Ogunsalu para la regeneración ósea por "sándwich" o membrana inter-posicional, ha sido exitosamente evaluada mediante TCEFU, concluyéndose que la misma consiste en la actividad osteoblástica con formación de hueso vascularizado que se integra al hueso circundante.

Mineralizaçäo da mandíbula de ratos em funçäo da administraçäo de flúor / Mineralization of rat mandibles under fluoride administration

A quantidade de cálcio, fósforo, magnésio e flúor foi avaliada na mandíbula de ratos com 30 e 60 dias de idade, que receberam, via bucal, doses diárias de 0,25 mg F, contidos em produto comercial tipo comprimido (Fluornatrium), a partir do nascimento. Os resultados obtidos evidenciaram que nos aniamis tratados o conteúdo de flúor foi maior aos 30 que aos 60 dias, ocorrendo o inverso com relaçäo ao cálcio, näo sendo observada nenhuma alteraçäo nos teores de fósforo e magnésio

Análise morfológica do arco maxilar superior em portadores de fissura transforame incisivo unilateral, operados: estudo longitudinal (3 a 9 anos de idade) / Morphologic analysis of the maxillary arch in operated unilateral cleft palate patients: a longitudinal study (from 3 to 9 years of age)

A análise morfológica do arco maxilar superior em fissurados transforame incisivo unilateral, operados, foi feita neste estudo, através do exame de 225 modelos de gesso do arco dentário superior de 40 pacientes do sexo masculino e 35 do sexo feminino, com idade variando de 3 a 9 anos, regularmente matriculados no Hospital de Pesquisa e Reabilitaçäo de Lesöes Lábio-Palatais da Universidade de Säo Paulo, em Bauru. Os pacientes foram divididos em dois grupos, o primeiro composto de pacientes submetidos a tratamento ortodôntico preventivo e o segundo de pacientes näo submetidos a tratamento ortodôntico preventivo. Todos os pacientes selecionados foram submetidos à cirurgia do lábio e do palato nos dois primeiros anos de vida. As cirurgias foram todas executadas por um único cirurgiäo e pela mesma técnica. Os modelos dos pacientes utilizados foram divididos de acordo com três fases representativas da evoluçäo do crescimento, considerando os grupos com e sem tratamento ortodôntico preventivo. Utilizando o método proposto por STOCKLI 1971 (70), foram demarcados nos modelos pontos de referência, utilizados para as dimensöes estudadas. Dos mesmos, obtivemos as cópias xerográficas e, através dos pontos demarcados, obtivemos os valores das distâncias utilizando um cursor de uma mesa digitalizadora acoplados e um microcomputador. Os resultados obtidos foram analisados estatisticamente e pudemos chegar às seguintes conclusöes...