Microcirculation changes in gingival tissue after ultrasonic tooth preparation in beagle dogs

Abstract Ultrasonic wave technology is widely used during dental treatments. We previously demonstrated that this method protects the gingival tissue. However, the physiological change on the gingival microvasculature caused by this method remains unclear. Objective The aim of this study was to investigate the relationship between the morphological and physiological effects on gingival microcirculation when preparing teeth, using the conventional dental turbine or ultrasonic method. Methodology The lower premolar teeth of beagle dogs were prepared along the gingival margin by using a dental turbine or ultrasonic wave instrument. Gingival vasculature changes were investigated using scanning electron microscopy for corrosion resin casts. Gingival blood flow at the preparation site was determined simultaneously by laser Doppler flowmetry. These assessments were performed immediately (Day 0), at 7 days and 30 days after tooth preparation. Results At day 0, in the turbine group, blood vessels were destroyed and some resin leaked. Furthermore, gingival blood flow at the site was significantly increased. In contrast, the ultrasonic group demonstrated nearly normal vasculature and gingival blood flow similar to the non-prepared group for 30 days after preparation. No significant alterations occurred in gingival circulation 30 days after either preparation; however, the turbine group revealed obvious morphological changes. Conclusions Based on multiple approach analyses, this study demonstrated that ultrasonic waves are useful for microvascular protection in tooth preparation. Compared with a dental turbine, ultrasonic wave instruments caused minimal damage to gingival microcirculation. Tooth preparation using ultrasonic wave instruments could be valuable for protecting periodontal tissue.

A limited and useful approach to determine proximal periodontal health / Un enfoque limitado y útil para determinar la salud proximal periodontal

Previous researchers have shown that there exists an interaction between gingival blood flow and gingival health. The purpose of this study was to compare the papillary blood flow at sites treated by a bridge with the blood flow at untreated sites. Twenty persons with resin-bonded fixed partial dentures were included in the study. The contralateral natural teeth of the site symmetrical to that of the restorations were used as controls. Blood flow was measured from the middle point of the papillae from both test and control sites by Laser Doppler Flowmetry (LDF). The plaque index, papillary bleeding index and probing depth measurements were recorded. There was a statistically significant difference between the test and control sites in papillary blood flow measurements and clinical indices (p < 0.05). Moreover, there was statistical significance between gingival blood flow measurements and papillary bleeding index in the experimental group (p < 0.05). In short, there exists an important relationship between resin-bonded fixed partial dentures and papillary blood flow. Although there were no correlations between LDF values and clinical parameters, it can be emphasized, within the limits of the study, that LDF readings have limited diagnostic value, at least when it comes to clinical performance of fixed prosthesis.

Investigadores anteriores han mostrado que existe una interacción entre el flujo de sangre gingival y la salud gingival. El propósito de este estudio fue comparar el flujo de sangre papilar en los sitios tratado por un puente, con el flujo de la sangre en los sitios no tratados. Veinte personas con prótesis dental parcial fija adherida con resina fueron incluidas en el estudio. Los dientes naturales contralaterales del sitio simétrico al de las restauraciones, se usaron como controles. El flujo de sangre se midió a partir del punto medio de las papilas de los sitios de prueba y de control, usando un medidor de flujo mediante Láser Doppler (LDF). Se registraron el índice de la placa, el índice de sangramiento papilar, y las mediciones para el examen de la profundidad. Hubo una diferencia estadísticamente significativa entre los sitios de la prueba y los de control en las mediciones del flujo de sangre papilar y los índices clínicos (p <0.05). Más aún: hubo una diferencia estadísticamente significativa entre las mediciones del flujo de sangre gingival y el índice de sangramiento papilar en el grupo del experimento (p <0.05). En resumen, existe una relación importante entre la prótesis dental parcial fija adherida con resina y el flujo de sangre papilar. Aunque no había ninguna correlación entre los valores de LDF y los parámetros clínicos, puede subrayarse - dentro de los límites del estudio - que las lecturas de LDF tienen un valor diagnóstico limitado, al menos cuando se trata del funcionamiento clínico de la prótesis fija.

Evaluation of the marginal gingival health using laser doppler flowmetry

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

Os objetivos deste estudo foram comparar o fluxo sangüíneo gengival (FSG) em sítios teste (dentes retentores de próteses parciais fixas) e sítios controle (dentes naturais contralaterais) e investigar se há alguma relação entre os índices clínicos (IC) e os valores de FSG. Doze indivíduos saudáveis (6 mulheres e 6 homens) com idades entre 20 a 54 anos participaram deste estudo. O FSG foi medido no ponto médio da gengina marginal em ambos os sítios teste e controle utilizando dopplerfluxometria a laser (DFL). Além disso, as medidas referentes ao índice de placa, índice gengival e profundidade de sondagem foram registradas. Foi observada diferença estatisticamente significante (p<0.05) entre os grupos teste e controle para os valores de FSG. Por outro lado, não houve diferença estatisticamente significante (p>0.05) entre os sítios teste e controle com relação aos índices clínicos, exceto para o índice de placa. Os achados deste estudo sugerem que existe uma relação significante entre próteses parciais fixas retidas por resina com margens localizadas subgengivalmente e o FSG marginal. Embora os índices clínicos sejam úteis para coletar informações sobre as condições clínicas dos tecidos gengivais, o FSG é uma ferramenta importante para medir o fluxo sanguíneo tissular gengival e avaliar a saúde periodontal. Em conclusão, a dopplerfluxometria a laser pode ser usada juntamente com índices clínicos para avaliar a saúde gengival marginal.