The Impact of Tooth Brushing on Teeth affected by Molar Incisor Hypomineralisation (MIH)

Background: Molar Incisor Hypomineralisation (MIH) can affect one or more first permanent molars (FPM), with or without the permanent incisors, prevalence ranges from 3-40%. Severity varies, and can be associated with hypersensitivity, post-eruptive breakdown (PEB) and aesthetic concerns. Different toothpastes have been suggested to enhance remineralization and reduce sensitivity, including fluoride or Novamin containing toothpastes. Aim: To compare tooth surface loss (TSL) from toothbrushing using different toothpastes in MIH affected and sound FPMs using Optical Coherence Tomography (OCT). Methods: Extracted human FPMs (N=27) Sound or with MIH were collected under ethical approval. Samples were classified using EAPD index 2014, in which type 21 indicates a white/cream opacity and type 22 yellow/brown opacity. Erosion using 1% citric acid was applied, followed by abrasion with an electric toothbrush and (i) saliva, (ii) Sensodyne® complete protection (inc Novamin), & (iii) Sensodyne® children pronamel (inc fluoride) for 100 cycles. A small needle was attached as a reference for calculation of TSL. OCT images were taken every 20 cycles, and the amount of TSL was calculated. Results: TSL was higher in children pronamel group than complete protection and saliva for MIH (type 22) and control samples, with the highest TSL 100µm and a mean of 85µm. The lowest TSL was 7µm in control group brushed with saliva. In MIH sample (type 21), the highest TSL was with Complete protection (85µm). However, the average mean of TSL for type 21 lesions with both complete protection and children pronamel groups was 45µm. Conclusion: Children Pronamel toothpaste resulted in more TSL, whereas complete protection resulted in less TSL in MIH type 22. This suggests Novamin may be beneficial in severely affected MIH teeth, but larger sample sizes are needed before a conclusion can be reached

Effect of Size and Concentration of PLGA-PEG Nanoparticles on Activation and Aggregation of Washed Human Platelets

Nanotechnology is being increasingly utilised in medicine as diagnostics and for drug delivery and targeting. The small size and high surface area of nanoparticles (NPs), desirable properties that allow them to cross biological barriers, also offer potential for interaction with other cells and blood constituents, presenting possible safety risks. While NPs investigated are predominantly based on the biodegradable, biocompatible, and FDA approved poly-lactide-co-glycolide (PLGA) polymers, pro-aggregatory and antiplatelet effects have been reported for certain NPs. The potential for toxicity of PLGA based NPs remains to be examined. The aims of this study were to determine the impact of size-selected PLGA-PEG (PLGA-polyethylene glycol) NPs on platelet activation and aggregation. PLGA-PEG NPs of three average sizes of 112, 348, and 576 nm were formulated and their effect at concentrations of 0.0–2.2 mg/mL on the activation and aggregation of washed human platelets (WP) was examined. The results of this study show, for the first time, NPs of all sizes associated with the surface of platelets, with >50% binding, leading to possible internalisation. The NP-platelet interaction, however, did not lead to platelet aggregation nor inhibited aggregation of platelets induced by thrombin. The outcome of this study is promising, suggesting that these NPs could be potential carriers for targeted drug delivery to platelets

Effect of size and concentration of PLGA-PEG nanoparticles on activation and aggregation of washed human platelets

Nanotechnology is being increasingly utilised in medicine as diagnostics and for drug delivery and targeting. The small size and high surface area of nanoparticles (NPs), desirable properties that allow them to cross biological barriers, also offer potential for interaction with other cells and blood constituents, presenting possible safety risks. While NPs investigated are predominantly based on the biodegradable, biocompatible, and FDA approved poly-lactide-co-glycolide (PLGA) polymers, pro-aggregatory and antiplatelet effects have been reported for certain NPs. The potential for toxicity of PLGA based NPs remains to be examined. The aims of this study were to determine the impact of size-selected PLGA-PEG (PLGA-polyethylene glycol) NPs on platelet activation and aggregation. PLGA-PEG NPs of three average sizes of 112, 348, and 576 nm were formulated and their effect at concentrations of 0.0-2.2 mg/mL on the activation and aggregation of washed human platelets (WP) was examined. The results of this study show, for the first time, NPs of all sizes associated with the surface of platelets, with >50% binding, leading to possible internalisation. The NP-platelet interaction, however, did not lead to platelet aggregation nor inhibited aggregation of platelets induced by thrombin. The outcome of this study is promising, suggesting that these NPs could be potential carriers for targeted drug delivery to platelets