Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

Objective: The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H2O2) on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods: Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results: There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p<0.05), whereas there were no significant differences found between the control and the other groups (p>0.05). Conclusions: Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.

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.