Comparison of clinician agreement during visualization of conventional and digitized bitewing radiographs.

Digital technology is becoming more common in dental practices. Indirect digitization of radiographs can be an alternative to direct digital systems. This study was designed to evaluate intra-observer, inter-observer, and inter-technique agreement of proximal caries diagnosis on bitewing radiographs before and after indirect digitization. Four bitewing radiographs were obtained from 50 dental students. Conventional films were digitized with a flatbed scanner at 150 and 300 dpi. Three observers recorded the presence and depth of caries on 1,642 proximal surfaces for the conventional and digitized radiographs. Radiographs were evaluated twice (one week apart), using each viewing technique. Intra-observer, inter-observer, and inter-technique agreement (Kw) were determined. The intra-observer, inter-observer, and inter-technique agreements of proximal caries diagnosis on bitewing radiographs before and after indirect digitization were moderate to good.

Etiology of xerostomia and dental caries among methamphetamine abusers.

This study reviews the peripheral effects of methamphetamine on the salivary acini, the pathogenesis of methamphetamine-induced xerostomia, and its anecdotal relationship to dental caries. Methamphetamine is a sympathomimetic central stimulant which is abused for its euphoric effects. Its pharmacological action is exerted indirectly by sustaining high levels of catecholamines in the synaptic cleft and directly by binding to the postsynaptic adrenergic receptors. Methamphetamine abusers report subjective perception of xerostomia, which cannot be explained by the direct peripheral action of methamphetamine on the secretory acini. The drug may cause a decrease in salivary flow rate by centrally inhibiting salivatory nuclei via stimulation of alpha-2 receptors in the brain. Drug mediated dehydration state may influence the perception of dry mouth in abusers. The decreased salivary flow rate, either due to a central inhibitory action of methamphetamine or generalised dehydration, likely contributes to the increased occurrence of dental caries. Five cases of methamphetamine abuse are presented, three of whom experienced rampant dental caries. A direct association between methamphetamine abuse and the occurrence of rampant caries was not clear.

Microtensile bond strength of total-etch and self-etch adhesives to the enamel walls of Class V cavities.

PURPOSE: To determine the difference in microtensile bond strengths (MTBS) of resin-based composite bonded to the enamel of cavity preparations using a conventional or a self-etching adhesive. METHODS: Buccal and lingual Class V cavities were prepared in each of 12 caries-free human molars. Six teeth were randomly selected to be restored with Spectrum TPH resin-based composite and Prime & Bond NT adhesive. The remaining six teeth were restored with the same composite and Prompt L-Pop self-etching adhesive. Enamel/composite sticks were cut from each specimen and subjected to microtensile bond testing. Each debonded specimen was evaluated by SEM to determine the mode of failure. RESULTS: The mean MTBS for Prime & Bond NT specimens was 15.2+/-13.1 MPa. The mean MTBS for Prompt L-Pop self-etching adhesive samples was 18.2+/-14.3 MPa. ANOVA demonstrated no statistically significant difference between the mean MTBS associated with the two adhesives (P> 0.05). The results of SEM analysis revealed that the bonding failures occurred primarily at the interface between the adhesive and the enamel, suggesting a primarily adhesive failure.