RESUMO
PURPOSE: To explore the effect of thick and thin sputum on the restoration of oral anterior teeth and the index of gingival crevicular fluid. METHODS: A study was conducted on 80 patients (130 teeth) who underwent full-ceramic crown treatment for anterior tooth restoration in Jiangnan University Affiliated Hospital 's oral clinic. The patients were divided into thick gingival type (42 cases, 67 teeth) and thin gingival type (38 cases, 63 teeth) according to their gingival biotype. The two groups were compared before and after the restoration with improved plaque index (mPI), modified bleeding index (mBI), probing depth (PD), clinical evaluation score of oral prosthesis, tumor necrosis factor-alpha (TNF-alpha) and IL-1 ß(interleukin-1ß) in gingival crevicular fluid. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: Before treament, there were no significant differences in mPI, mBI and PD between the two groups (Pï¼0.05); 12 months after treament, mPI, mBI and PD of the thin gingiva group were significantly lower than those of the thick gingiva group(Pï¼0.05). Before treament, there were no significant differences in TNF-α and IL-1ß levels in gingival crevicular fluid between the two groups(Pï¼0.05); 12 months after treament, TNF-α and IL-1ß levels of the thin gingiva group were significantly lower than those of the thick gingiva group(Pï¼0.05). Six months after treament, there were no significant differences in prosthesis integrity, marginal adaptation, color matching, periodontal health status and secondary caries scores between the two groups (Pï¼0.05); 12 months after treament, the marginal adaptation, periodontal health status and secondary caries scores of the thick gingiva group were significantly higher than those of the thin gingiva group(Pï¼0.05); the marginal discoloration score of the thick gingiva group was significantly lower than that of the thin gingiva group at 6 months and 12 months after treament(Pï¼0.05). CONVLUSIONS: The thin sputum type is more conducive to repairing the oral cavity after treatment, and is beneficial to the maintenance of oral health condition after repair. The gingival index of the thick sputum type patient will be significantly increased after repair, and the risk of gingival inflammation is increased. The aesthetic effect is better than the thin sputum type.
Assuntos
Gengiva , Líquido do Sulco Gengival , Humanos , Fator de Necrose Tumoral alfa , Índice Periodontal , CoroasRESUMO
Fourier transform infrared (FTIR) spectroscopy was used to study the chemical changes of masson pine (pinus massoniana lamb.) decayed by the brown-rot fungus Wolfiporia cocos (Schwein.) Ryvarden & Gilbn. for different durations up to 23 weeks. The ratios of height of the lignin/holocellulose and holocellulose/lignin IR peaks were measured, and the klason lignin content and holocellulose content of the sound wood and brown-rotted wood with different level of decay were analyzed by wet chemical methods. The relationship between the two chemical components and the ratios of IR peak height was also established. FTIR spectra showed that, during the first 15 weeks of decay, the intensity of absorption bands at 1 736 and 1 372 cm(-1) ascribed to holocellulose decreased gradually, accompanied by a successive increase in the intensity of band at 1 510 and 1 225 cm(-1) ascribed to lignin. However, the intensities of holocellulose bands at 1736 and 1372 cm(-1) had a little increase, and the intensities of lignin bands at 1 510 and 1 225 cm(-1) had a very slight decrease after 15 weeks of decay. There was a very good correlation between the ratios of height of the lignin/holocellulose (I1510/1736, I1510/I1372, I1225/I736 and I1225/I1372) and the klason lignin content or holocellulose content. The coefficients of determination for the klason lignin content and the holocellulose content were 0.97-0.99 and 0.96-0.97, respectively. High coeffieients of determination were also obtained between the holocellulose/ lignin peak height ratios and the holocellulose content (R2 = 0.96). The above results suggest that, in the system studied, the klason lignin content and holocellulose content of wood decayed to differnent levels could be determined with reasonable accuracy by the FTIR technology.
Assuntos
Fungos , Lignina/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Madeira/análise , PinusRESUMO
The FTIR, UV-Visible, 1H NMR and GPC were used to study structural changes of brown-rotted lignin after sodium borohydride reduction. FTIR spectra showed that, after reduction, the band at 1,677 cm(-1) attributed to the conjugated carbonyl groups disappeared, and the band intensity at 1,715 cm(-1) attributed to the nonconjugated carbonyl groups decreased. On the other hand, the band at 1,509 and 1,603 cm(-1) attributed to aromatic skeletal vibration remained almost unchanged. UV spectra showed the decreased absorptions at 288 nm and 300-400 nm after reduction. 1H NMR spectra showed that, after reduction, the number of aromatic methoxyl and aromatic hydroxyls decreased, the number of aliphatic hydroxyls and the proton number attributed to many linkage structures connecting the phenylpropane units increased. GPC results showed that the molecular weight of reduced brown-rotted lignin increased and the molecular distribution got wider, as a consequence of the large molecular weight molecules generated during the reduction reaction. Our results suggest that the conjugated carbonyl groups can be totally reduced to the hydroxyl groups, but only some nonconjugated carbonyl groups can be reduced to the hydroxyl groups. The chemical structure of the brown-rotted lignin changed, but the benzyl ring kept stable. The condensation reaction took place during the sodium borohydride reduction process.
Assuntos
Boroidretos/química , Lignina/química , Radical Hidroxila , Espectroscopia de Ressonância Magnética , Peso Molecular , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The contents of holocellulose and lignin of wood are important determinants of the pulping quality of wood. The determination of holocellulose and lignin contents using traditional chemical methods is a costly and time-consuming process. Near infrared reflectance (NIR) analysis offers a fast, nondestructive testing and low cost alternative for prediction of wood quality. In the present article, the total amounts of holocellulose and lignin contents of 48 samples were analyzed according to standard wet-chemical method. All samples were milled using a Standard Wiley knife mill with a 2 mm screen. The 2 mm material was sieved with a 40-60 mesh sieve. Then, near infrared (NIR) spectra were collected in diffuse reflectance from samples of meal contained in a spinning cup by an analytical spectral devices (ASD) Lab Spec at wavelengths between 350 nm and 2 500 nm. The raw spectra were pretreated by the second derivative and smoothing, then the NIR model was built using partial least-squares statistical analysis and full cross validation. The coefficients of correlation (r) of calibration and validation for holocellulose were 0. 96 and 0.93, respectively; the standard error of calibration (SEC) and the standard error of prediction (SEP) were 0.39 and 0.50, respectively. For lignin, the values for r of calibration and validation were 0.99 and 0.90, while the SEC and SEP were 0.10 and 0.28, respectively. It was concluded that NIR analysis is a reliable, fast and nondestructive testing predictor of holocellulose and lignin content of wood in Chinese fir.
Assuntos
Celulose/análise , Cunninghamia/química , Lignina/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Calibragem , Celulose/metabolismo , Lignina/metabolismo , Controle de Qualidade , Reprodutibilidade dos Testes , Madeira/análise , Madeira/químicaRESUMO
Lignin is one of the main components of lignocellulosic materials. The main purpose of wood cooking and bleaching is to remove lignin by chemical agent in paper industry. Whereas the lignin content shows wide variations depending on its tree specie, site condition, part and so on, it is essential to analyze the lignin content of different raw material. The aim of this paper is to develop a rapid near infrared (NIR) reflectance spectroscopic method to characterize the Klason lignin content of bamboo. Fifty four samples from three growth years, two positions along the longitudinal directions and three positions along the radial directions within a bamboo pole were prepared. The Klason lignin contents of 54 samples were analyzed according to traditional chemical method, the spectra of these samples were collected by NIR in the range of 350 to 2500 nm, and the relationship between the lignin content and the spectra of these samples was established by multivariate statistical technique. After second derivative pretreatment of raw spectra, the Klason lignin contents of the bamboo samples were quantified using partial least-squares statistical analysis (PLS1) and full cross validation in the range of 1011-1675 nm and 1930-2488 nm. High coefficients of correlation (r) were obtained between the predicted NIR results and those obtained from traditional chemical method. The correlation coefficient of calibration model and prediction model was 0.99 and 0.97, respectively. The standard error of calibration (SEC) and standard error of prediction (SEP) was 0.36% and 0.59%, respectively. It was found that the lignin content in bamboo could be determined rapidly with reasonable accuracy by the NIR method.