Oral cleansing effect of sugar-free chewing gum with sodium hexametaphosphate and xylitol.

The aim of the study was to find out the effect of sugar-free chewing gums (xylitol and sorbitol) on plaque and gingivitis among 14-15-year-old school children. A single center, double-blind, randomized controlled trial was conducted on 14-15-year-old children. Sample size was determined to be 48. Participants were randomly allocated to test group (xylitol [n = 12], sorbitol [n = 12]) and control group (no gum, n = 24). Duration of the study was 14 days. Baseline assessment of plaque, gingival, and bleeding score, followed by oral prophylaxis. Selected children received daily two chewing gum (1.1 g each) to chew for 20 min postbreakfast and postlunch. Follow-up was done on 15th day. Analysis was done using independent t-test, ANOVA, and post hoc test. Significance level was kept at P < 0.05. There was a significant reduction in plaque, gingival, and bleeding score in test group (P < 0.05) compared to control group. Sugar-free gum (xylitol and sorbitol) significantly reduced the plaque, gingival, and bleeding score.

Aim The purpose of the study was to compare the changes in salivary pH and salivary flow rate after chewing xylitol-containing chewing gum in children at high risk and low risk for dental caries.Method Forty school children aged 9 to 12 years were selected for the study according to the inclusion criteria and were divided into two groups - Group A 20 children at high caries risk for dental caries and Group B 20 children at low risk for dental caries. Initially baseline saliva samples were collected for both the groups and subjected to salivary pH and flow rate assessment. Following this the children were instructed to chew xylitol-containing sugar-free chewing gum for 10 minutes. Salivary pH assessment was done at different time intervals like 0 15 30 45 and 60 minutes. The salivary flow rates were measured once the froth settled.Results Data was analyzed statistically using repeated-measures ANOVA. After chewing sugar-free gum salivary flow rate showed no significant difference pgt0.05 between Group A and Group B whereas salivary pH showed a statistically significant difference plt0.001 between the two groups at different time intervals.Conclusion Xylitol-containing sugar-free chewing gum showed an elevated salivary pH in children at high risk for dental caries when compared to the low-risk group while it showed an equal effect on salivary flow rate in both the groups. Xylitol-containing chewing gums were more effective in children at high risk for dental caries than the low-risk group.

To study the results of implantation of preformed hydroxyapatite (HA) disks and HA cement in onlay augmentation. In this prospective study involving 16 adult New Zealand rabbits, HA disk and HA cement samples were implanted separately and together along the bony and cartilaginous nasal dorsum as well as over the supraorbital bone. Gross and histologic examinations of the implants were performed at intervals ranging from 3 to 24 months. There was no evidence of infection, adverse reaction, or implant extrusion in the 15 rabbits surviving the planned period. Grossly, all rabbits had prominent noses and supraorbital regions that were immobile on digital palpation. No measurable change in HA disk height and width was noted but there was a 15% decrease in height and width in the HA cement implant. Microscopically, preformed HA disks were found to be enclosed in a vascularized fibrous capsule. When disks were combined with HA cement, a vascular fibrous capsule was still noted around the implant but there was osteoconversion in the underlying cement layer. Used alone, HA cement underwent both osteoconversion and osteointegration. Neither the preformed HA disk with and without HA cement nor the HA cement alone elicited giant cell reaction or inflammatory changes. The HA cement alone was found to have microscopic fissures at the edges. This animal study suggests that preformed HA implants and HA cement, alone or in combination, can be used to augment the non-stress-bearing craniofacial skeleton.

Effects of polyphosphates and fluoride on hydroxyapatite dissolution: A pH-stat investigation

48 - Calcium Phosphate Nanoparticles Tested on Hydroxyapatite Discs as Remineralising Agent

The present study aims to establish a standardized model that makes it possible to evaluate the dynamic dissolution of biofilm, killing of biofilm microbes and inhibition of growth of biofilm by disinfecting solutions. Biofilm was grown from dental plaque bacteria on collagen-coated hydroxyapatite (HA) disks for 3 days or 3 weeks under anaerobic conditions. Biofilms were stained with the LIVE/DEAD viability stain and subjected to sterile water, 2% sodium hypochlorite (NaOCl), 6% NaOCl, or 2% chlorhexidine (CHX) for 32 min. Dynamic change in fluorescence on bacterial cells and extracellular polymeric substance (EPS) during the exposure was analyzed using Alexa Fluor 647-labeled dextran conjugate and a live-cell imaging confocal laser scanning microscopy (LC-CLSM). The biofilm structures after treatments were visualized by scanning electron microscopy (SEM). The treated biofilms on HA disks were collected and subjected to colony forming unit (CFU) counting. Another set of sterile HA disks were coated with CHX prior to the monitoring of plaque biofilm growth for 12 h. The LC-CLSM results showed that NaOCl dissolved biofilm effectively, more so at a higher concentration and longer exposure time. Six percent NaOCl was the most effective at dissolving and killing bacteria (e.g., 99% bacterial reduction in 3-day-old biofilm and 95% bacterial reduction in 3-week-old biofilm in 32 min) followed by 2% NaOCl and CHX. Sodium hypochlorite dissolved over 99.9% of the EPS whereas CHX only slightly reduced the EPS biovolume in 32 min. CFU results indicated that the dispersed biofilm bacteria are more resistant than planktonic bacteria to disinfectants. SEM showed the disruption of biofilm after exposures to CHX and NaOCl. The use of 2% CHX and sterile water did not result in biofilm dissolution. However, prior exposure of the HA disks to 2 and 0.2% CHX for 3 min prevented biofilm from growing on the HA disk surfaces for at least 12 h. This new platform has the potential to aid in a better understanding of the antibiofilm properties of oral disinfectants.

Depending on the frequency and type of intake, milk can affect caries formation by virtue of its demineralisation- remineralisation properties. The effect of A2 milk on human dentition is still unexplored. Hence,the aim of the present study was to evaluate and compare the remineralising and adsorption properties of regular cow milk and A2 milk using Human Enamel discs and Hydroxyapatite(HA) discs in an in-vitro model. Materials and methods: To evaluate the remineralising properties of milk, 24 human enamel discs and 24 Hydroxyapatite(HA) discs were divided equally into two different milk groups. Subsurface carious lesions were created and they were subjected to remineralisation-demineralisation cycles using twenty-one-day pH-cycling model. Baseline, post-demineralisation and post-remineralisation differences between the groups were studied by microhardness test (Vicker’s Indenter) and surface roughness test (profilometer). Ca:P ratio of the subtrates was analysed using Scanned Electron Microscopy Energy Dispersive X-Ray (SEM-DEX) analysis of five HA discs, out of which two were treated with the different milk types and the remaining three with different controls. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) based analysis, followed by densitometric evaluation was performed to examine the adsorption of caseins from the two milk types on HA discs.

Antibiofilm peptides against biofilms on titanium and hydroxyapatite surfaces

The present study evaluated the antioxidant effect of green and black tea (Camellia sinensis L.) extracts in uncured pork sausages. The total polyphenol content in the green tea extract (GTE) was significantly higher (p < 0.05) than the black tea extract (BTE). DPPH assay showed significantly higher (p < 0.05) antioxidant activity in GTE compared to BTE. However, TBARS values of uncured pork sausages significantly reduced (p < 0.05) for all levels of concentrations of BTE (0.05%, 0.10%, 020%, and 0.30%) and GTE (0.05%, 0.10, 0.20%, and 0.30%) during the 5 days storage period. The reduction of TBARS values for the BTE 0.05% treated sausage sample was not, however, significantly different (p > 0.05) to the BHT 0.10% treated sausage sample on fifth day of the storage period. The sensory evaluation of pork sausages incorporated with a BTE of 0.05% and 0.30%, GTE of 0.05% and the control were not significantly differences (p < 0.05) in color, odor, texture, juiciness, taste, or overall acceptability. Practical applications In the present study, we evaluated the antioxidant effect of green and black tea (Camellia sinensis L.) extracts in uncured pork sausages. Adding of black tea extract 0.05%, 0.30%, and green tea extract 0.05% can reduce the TBARS value in uncured pork sausages without altering color, odor, texture, juiciness, or overall acceptability. Therefore, 0.05%, 0.30% black tea extract and 0.05% green tea extracts can be considered as potential antioxidants in uncured pork sausages.

Transplantation of hepatocytes cultured on hydroxyapatite into Nagase analbuminemia rats

Rat hepatocytes were seeded in porous hydroxyapatite (HA) disks for hepatocyte transplantation to Nagase analbuminemic rat (NAR). To increase the cell density in the HA, cell suspension in the tube containing the disks were centrifuged down. The centrifugation increased the viable cell number in HA disk approximately 4-fold over the static method. The HA disks were intraperitoneally transplanted into NARs and harvested three weeks after the transplantation. Angiogenesis with no obvious inflammatory reaction was found inside the pore areas of HA. The ectopic transplantation well supported the viability of hepatocytes seeded in HA disks evidenced by significant increases in the host rats' serum albumin level as time passed after the transplantation.

Interactions of perfluoroalkyl surfactants to teeth in vitro and in vivo

Selenium (Se) is one of the essential trace elements for human, but the Se deficiency of most areas resulting in low a Se content in fruits. To increase the Se uptake in fruit trees, the effects of foliar spraying four types of tea (black, green, white, and dark) infusions on the growth and Se uptake of Cyphomandra betacea were studied using a pot experiment. The white and dark tea infusions increased the biomass, superoxide dismutase activity, and catalase activity of C. betacea, while the black and green tea infusions had no significant effects. The green, white, and dark tea infusions increased the contents of photosynthetic pigments in C. betacea, the while the black tea infusions had no significant effects. The black, white, and dark tea infusions increased the peroxidase activity of C. betacea, while the green tea infusion decreased. All tea infusions increased the potassium (K) content in aboveground part of C. betacea and phosphorus (P) content in leaves to some extent. The different tea infusions decreased the Se contents in roots and shoots of C. betacea. Compared to the control, the black, green, white, and dark tea infusions decreased the Se contents in shoots by 16.67%, 27.30%, 33.33%, and 40.07%, respectively. Correlation analysis showed that the contents of P and K were negatively correlated with the Se content. Therefore, foliar spraying tea infusion can decrease the Se uptake in C. betacea, and the white and dark tea infusions can promote C. betacea growth.

Availability of bone marrow stromal cells in three-dimensional coculture with hepatocytes and transplantation into liver-damaged mice

The aim of this study was to investigate the atomic composition and the proteome of the salivary proteins adsorbed on the surface of orthodontic metallic bracket. For this, the atomic composition of orthodontic metallic brackets was analyzed with X-ray Photoelectron Spectroscopy (XPS). The acquired bracket pellicle was characterized after brackets were immersed in human whole saliva supernatant for 2 hours at 37°C. Hydroxyapatite (HA) discs were used as a control. Acquired pellicle was harvested from the HA discs (n = 12) and from the metallic brackets (n = 12). Proteomics based on mass spectrometry technology was used for salivary protein identification and characterization. Results showed that most of the proteins adsorbed on the surface of orthodontic metallic brackets and on the HA discs were identified specifically to each group, indicating a small overlapping between the salivary proteins on each study group. A total of 311 proteins present on the HA discs were unique to this group while 253 proteins were unique to metallic brackets, and only 45 proteins were common to the two groups. Even though most proteins were unique to each study group, proteins related to antimicrobial activity, lubrication, and remineralization were present in both groups. These findings demonstrate that the salivary proteins adsorbed on the bracket surface are dependent on the material molecular composition.