Colour and chemical stability of bismuth oxide in dental materials with solutions used in routine clinical practice.

Bismuth(III) oxide is included as a radio-opacifier in dental materials, including hydraulic silicate cements, the material of choice for several endodontic procedures. It has been implicated in tooth discoloration after contact with endodontic irrigants, in particular NaOCl solution, To date, there has been no work on the chemistry: all reports have been of clinical findings only. The purpose now was to report the reactions leading to colour change from Bi2O3 in contact with solutions used in routine endodontic practice.

An in vitro investigation of pre-treatment effects before fissure sealing.

Background: Fissure sealants prevent occlusal caries in permanent molars. Enamel preparation methods are used before fissure sealing.

Aims: To investigate effects of bioglass air-abrasion pre-treatment with and without an adhesive, on fissure enamel of permanent teeth, with respect to etchability, microleakage and microtensile bond strength.

Origins of bone repair in the armour of fossil fish: response to a deep wound by cells depositing dentine instead of dermal bone.

The outer armour of fossil jawless fishes (Heterostraci) is, predominantly, a bone with a superficial ornament of dentine tubercles surrounded by pores leading to flask-shaped crypts (ampullae). However, despite the extensive bone present in these early dermal skeletons, damage was repaired almost exclusively with dentine. Consolidation of bone, by dentine invading and filling the vascular spaces, was previously recognized in Psammolepis and other heterostracans but was associated with ageing and dermal shield wear (reparative).

Effect of loading on the microtensile bond strength and microleakage of a self-etching and etch-and-rinse adhesive in direct Class II MOD composite restorations in vitro.

The effect of loading on microleakage and microtensile bond strength of MOD composite restorations bonded with either self-etching or etch-and-rinse adhesive was investigated. MOD cavities were prepared in 28 extracted molar teeth. 14 teeth were bonded with a one-step self-etching adhesive (G-Bond) and 14 with an etch-and-rinse adhesive (Optibond Solo Plus) then restored with resin composite.

An in situ study investigating dentine tubule occlusion of dentifrices following acid challenge.

Objectives: To investigate the dentine occlusion and acid resistance of dentifrices developed to treat dentine hypersensitivity.

Methods: This was a single centre, single blind, randomised, split mouth, four treatments, two period crossover, in situ study in healthy subjects. Subjects wore buccal intra-oral appliances each fitted with four dentine samples over four consecutive days with one study product applied per appliance; 8% strontium acetate in silica base, 1040 ppm sodium fluoride (Sensodyne(®) Rapid Relief), 8% arginine, calcium carbonate, 1450 ppm sodium monofluorophosphate (Colgate Sensitive Pro-Relief(®)), 1450 ppm sodium fluoride (control paste) and water.