Effects of Calcium and Phosphate on Dissolution of Enamel, Dentin and Hydroxyapatite in Citric Acid.

The aim was to evaluate the effect of dissolved calcium and phosphate on dissolution rate of enamel, dentin and compressed hydroxyapatite (HA) in citric acid solution as a function of pH. At pH 2.5, dissolution rate of enamel increased significantly by 6% in 20 mmol/L added calcium but, otherwise, dissolution rates of neither enamel, dentin nor HA were significantly affected by 10 or 20 mmol/L calcium.

Randomised controlled trial of a microneedle patch with a topical anaesthetic for relieving the pain of dental injections.

Objectives: To determine whether a microneedle patch combined with 5% topical lidocaine reduces dental injection pain more than a patch without microneedles combined with 5% topical lidocaine.

Methods: This proof of principle randomised, two-treatment, double-blind, crossover split-unit design study in 16 healthy participants investigated levels of perceived pain from 3 increasing pain provoking challenges, when topical 5% lidocaine dental gel was applied to the oral mucosa with a microneedle patch and a patch with no microneedles, prior to infiltration with local anaesthesia on 2 visits. Pain was assessed by visual analogue scale (VAS) and 4-point verbal rating scale (VRS).

The interactions between attrition, abrasion and erosion in tooth wear.

Tooth wear is the result of three processes: abrasion (wear produced by interaction between teeth and other materials), attrition (wear through tooth-tooth contact) and erosion (dissolution of hard tissue by acidic substances). A further process (abfraction) might potentiate wear by abrasion and/or erosion. Knowledge of these tooth wear processes and their interactions is reviewed.

A randomised crossover trial to compare the potential of stannous fluoride and essential oil mouth rinses to induce tooth and tongue staining.

This study compared the staining potential of two experimental amine fluoride/stannous fluoride mouth rinses (A and B), a phenolic/essential oil rinse (C) and a negative control, water, rinse (D). The study was a single centre, randomized, single-blind, four treatment crossover study design among healthy participants. Prior to each study period, participants received a dental prophylaxis.

Inhibition of hydroxyapatite dissolution by whole casein: the effects of pH, protein concentration, calcium, and ionic strength.

Formulating drinks with reduced erosive potential is one approach for reducing dental erosion. In this study, whole casein was added to citric acid solutions representative of soft drinks, and the hydroxyapatite dissolution rate was assessed. Adding 0.

Meta-analyses of studies of 0.2% delmopinol mouth rinse as an adjunct to gingival health and plaque control measures.

Background: Delmopinol is a third-generation anti-plaque agent used as a mouthwash to reduce plaque and alleviate gingivitis.

Objective: To create an overview of the anti-plaque efficacy of 0.2% delmopinol as an adjunct to normal oral hygiene measures by meta-analysis of completed clinical trials.

Tooth brushing, tooth wear and dentine hypersensitivity--are they associated?

Evidence suggests that patients suffer the painful symptoms of dentine hypersensitivity when dentine is exposed and the dentinal tubule system is opened to the oral cavity to allow stimuli to trigger a neural response in the pulp via a hydrodynamic mechanism. The processes needed to localise lesions of dentine hypersensitivity include loss of enamel and/or gingival recession. Whilst tooth brushing with or without toothpaste appears to cause minimal wear to enamel (in the absence of acids), circumstantial evidence implicates tooth brushing with gingival recession and exposure of dentine.

Tooth bleaching by different concentrations of carbamide peroxide and hydrogen peroxide whitening strips: an in vitro study.

Objective: To investigate the tooth whitening effects of various concentrations of carbamide peroxide (CP) gels and 6% hydrogen peroxide (HP) whitening strips used on an intrinsic, in vitro stain model in a simulated home-applied bleaching protocol.

Method: Extracted third molars were sectioned and stained to Vita shade C4 using a standardized tea solution. Stained specimens were then bleached with 10, 15, 20, 22, and 30% CP gels applied in custom-made trays for 8-hour sessions for 14 days.

An investigation of some food-approved polymers as agents to inhibit hydroxyapatite dissolution.

Dental erosion involves dissolution of the hydroxyapatite fraction of enamel and dentine, so agents that reduce the dissolution rate of hydroxyapatite could find application in food products aimed at reducing erosion. This study was performed to test some common food ingredients and additives for their effect on the dissolution rate of hydroxyapatite in a citric acid solution representative of soft drinks. Pyrophosphate, tripolyphosphate and a linear chain polyphosphate (average 25 phosphate units) significantly reduced the hydroxyapatite dissolution rate by 35, 46 and 64%, respectively.

Tooth brushing, tooth wear and dentine hypersensitivity--are they associated?

Evidence suggests that patients suffer the painful symptoms of dentine hypersensitivity when dentine is exposed and the dentinal tubule system is opened to the oral cavity to allow stimuli to trigger a neural response in the pulp via a hydrodynamic mechanism. The processes needed to localise lesions of dentine hypersensitivity include loss of enamel and/or gingival recession. Whilst tooth brushing with or without toothpaste appears to cause minimal wear to enamel (in the absence of acids), circumstantial evidence implicates tooth brushing with gingival recession and exposure of dentine.

Comparison of three in-office bleaching systems based on 35% hydrogen peroxide with different light activators.

Purpose: To compare in vitro the bleaching effects obtained with and without the use of the various lights on power bleaching systems.

Methods: 19 groups of five tooth specimens were prepared and allocated randomly to treatments. Only specimens with shade C4 were accepted for the study.

The effect of unstimulated and stimulated whole saliva on extrinsic staining in vitro--a developmental method.

Objectives: To detect any differences in the propensity of unstimulated and stimulated, individual whole saliva to cause in vitro staining by chlorhexidine and tea.

Methods: Unstimulated and stimulated human saliva was collected on a daily basis and used to coat optically clear acrylic specimens. Specimens were subjected to an established chlorhexidine/tea staining model in vitro shown to correlate well with in vivo staining, and cycles repeated until an optical density of <2 was reached.

Correlation and examiner agreement between a new method of plaque scoring and a popular established plaque index, modelled in vitro.

Background, Aims: Scoring of supragingival plaque is common to epidemiological studies, oral hygiene assessments and clinical trials of oral hygiene products. These clinical practices utilize indices such as the Turesky et al. (1970, Journal of Periodontology 41, pp.

Radiological examination of dental castings -- a review of the method and comparisons of the equipment.

The mechanical stability of crowns or bridges as well as frameworks for removable partial dentures depends on factors like thickness and metal structure. The biological compatibility can be influenced by porosities and soldered joints. Radiological testing is a non-destructive method to check defects in dental castings.