A randomized split mouth clinical trial of the application of the desensitizer agents for tooth sensitivity

Background: Dentin hypersensitivity (DH) affects 3%-75% of the people and is one of the morbid tooth conditions. Hence in the present study we aim to examine the clinical effectiveness of 3 different desensitizing agents in decreasing pain of DH in time of 1 month.Methods: Fifty subjects with cervical DH in at least one tooth in any three of the 4 quadrants were selected. VAS was used to note the pain. Each quadrant in an individual was randomly assigned. Profluorid varnish, Admira protect, and PRG‑Barrier coat was used. VAS scores for the tactile and air stimuli were noted immediately after application, 1 week, and after 1 month. The data was analyzed keeping p<0.05 as significant.Results: VAS significantly reduced for all three groups from the base line (p<0.001). Admira protect showed significant reduction of hypersensitivity scores at 1 month compared to other groups (p<0.001).Conclusions: Admira protect was better at lowering the pain due to DH than PRG‑barrier coat and Profluorid varnish after 1 month of application.

Sensitivity treatments for teeth with Molar-Incisor Hypomineralization (MIH): Protocol for a Randomized Controlled Trial (Preprint)

BACKGROUND The sensitivity of teeth with MIH (Molar Incisor Hypomineralization) can affect children’s quality of life and is a challenging problem for dentists. Remineralizing agents such as sodium fluoride varnish seem to reduce sensitivity of teeth with MIH, but long-term clinical trials with large samples are still needed for more consistent results about its effectiveness as a desensitizing agent before its clinical recommendation. OBJECTIVE This randomized clinical trial aims to compare three treatment interventions for teeth with MIH and hypersensitivity. METHODS : 60 children aged 6-10 years presenting with at least one first permanent molar with sensitivity and no loss of enamel will be randomly assigned to three groups: Control group - sodium fluoride varnish (Duraphat®, Colgate); Experimental group I - 4% titanium tetrafluoride varnish (TiF4); and Experimental group II - coating resin containing S-PRG filler (Surface Pre-Reacted Glass ionomer) (SPRG Barrier Coat®, Shofu). The sodium fluoride varnish and 4% titanium tetrafluoride varnish will be applied once a week for 4 consecutive weeks and the S-PRG-Barrier Coat resin will be applied in the first session and the application will be simulated in the following 3 weeks to guarantee the blinding of the study. The primary outcome will be sensitivity level measured in different moments: before each material application, immediately after application or simulation, and 1, 2, 4, and 6 months after the last application/simulation by one examiner using Wong-Baker Facial Scale (WBFS), Schiff's Cold Air Sensitivity Scale (SCASS), and FLACC Pain Scale (Face, Legs, Activity, Cry, Consolability pain scale). As secondary outcomes, the parental satisfaction and child self-reported discomfort after the treatment will be measured with a questionnaire prepared by the researcher. The data will undergo statistical analysis and the significance level will be set at 5%. RESULTS The project was funded in 2018, and enrollment was completed in November 2019. The recruitment of participants is currently under way and the first results are expected to be submitted for publication in 2022. CONCLUSIONS If found effective in reducing the patient’s sensitivity with long-term effects, these agents can be considered a treatment choice, and the findings will contribute with the development of a treatment protocol for teeth with sensitivity due to MIH. CLINICALTRIAL Brazilian Registry of Clinical Trials Universal Trial Number: U1111-1237-6720; http://www.ensaiosclinicos.gov.br/rg/?q=RBR-4BHXPB

Protective Effects of GIC and S-PRG Filler Restoratives on Demineralization of Bovine Enamel in Lactic Acid Solution

This study was aimed at investigating the protective effects of glass ionomer cement (GIC) and surface pre-reacted glass ionomer (S-PRG) fillers used as dental restorative materials on demineralization of bovine enamel. GlasIonomer FX ULTRA (FXU), Fuji IX GP Extra (FIXE), CAREDYNE RESTORE (CDR) were used as GICs. PRG Barrier Coat (BC) was used as the S-PRG filler. They were incubated in a lactic acid solution (pH = 4.0) for six days at a temperature of 37 °C. The mineral was etched from the enamel surface, and a large number of Ca and P ions were detected in solution. The Al, F, Na, Sr, and Sr ions were released in GICs and S-RPG fillers. The Zn ion was released only in CDR and the B ion was released only in BC. The presence of apparent enamel prism peripheries was observed after six days of treatment for the group containing only enamel blocks. pH values for the FXU, FIXE, CDR, BC, and enamel block groups after six days were 6.5, 6.6, 6.7, 5.9, and 5.1, respectively. Therefore, the observed pH neutralization effect suppressed progression of caries due to the release of several ions from the restoratives.

Thermal Fatigue Life Prediction of Thermal Barrier Coat on Nozzle Guide Vane via Master–Slave Model

The aim of this paper was to develop a master–slave model with fluid-thermo-structure (FTS) interaction for the thermal fatigue life prediction of a thermal barrier coat (TBC) in a nozzle guide vane (NGV). The master–slave model integrates the phenomenological life model, multilinear kinematic hardening model, fully coupling thermal-elastic element model, and volume element intersection mapping algorithm to improve the prediction precision and efficiency of thermal fatigue life. The simulation results based on the developed model were validated by temperature-sensitive paint (TSP) technology. It was demonstrated that the predicted temperature well catered for the TSP tests with a maximum error of less than 6%, and the maximum thermal life of TBC was 1558 cycles around the trailing edge, which is consistent with the spallation life cycle of the ceramic top coat at 1323 K. With the increase of pre-oxidation time, the life of TBC declined from 1892 cycles to 895 cycles for the leading edge, and 1558 cycles to 536 cycles for the trailing edge. The predicted life of the key points at the leading edge was longer by 17.7–40.1% than the trailing edge. The developed master–slave model was validated to be feasible and accurate in the thermal fatigue life prediction of TBC on NGV. The efforts of this study provide a framework for the thermal fatigue life prediction of NGV with TBC.

A reinforced thermal barrier coat of a Na–tannic acid complex from the view of thermal kinetics

A reinforced thermal barrier coat of a Na–tannic acid complex controls the high flammability of cotton.

Formulation and Evaluation of Novel Enteric Coated Extended Release Multiparticulates of Model NSAID Ketoprofen

The aim of this study was to develop a pH responsive enteric coated extended release multiparticulate dosage form containing a model drug ketoprofen, a nonsteroidal anti-inflammatory drug used for rheumatoid arthritis. The drug loaded pellets in matrix form were prepared by using extrusion/spheronization method. The optimized pelletization method revealed that extrusion using 1 mm sieve plate and spheronization friction disc of 2mm carried out at 700 rpm for 5-10 minutes resulted in good spherical pellets and uniformity in size. Evaluated core pellets were coated with polymer Eudragit® RS 30D on Fluid bed coater to achieve a sustainable release for 12 hours. Ketoprofen as like other NSAID have been reported for gastric mucosal irritation so a pH responsive barrier coat of Eudragit L®100-55 was employed on a pan coater for abstaining release in acidic media. The formulated pellets were characterized for shape and size uniformity, friability, surface morphology studies. The particle size of core and polymer coated pellets were found to be in the range of 0.95-1.2 mm and 1.32-1.51 mm respectively. The pellets were spherical in shape with smooth texture and uniformity in size. In-vitro dissolution tests were carried out for pellets in a USP type II dissolution apparatus in media-simulating pH conditions of the gastrointestinal tract. The release of the ketoprofen from formulated pellets was established in pH 1.2 for a period of 2 h, followed by pH 7.5 for rest of the study. The study concluded that the formulated multiparticulate dosage form of ketoprofen was able to relieve symptoms of rheumatoid arthritis.