Effect of magnification loupes on dental hygiene student posture.

The chair-side work posture of dental hygienists has long been a concern because of health-related problems potentially caused or exacerbated by poor posture. The purpose of this study was to investigate if using magnification loupes improved dental hygiene students' posture during provision of treatment. The treatment chosen was hand-scaling, and the effect of the timing of introduction of the loupes to students was also examined.

Existence of an electrically insulating layer in amalgam-containing galvanic couples.

Objective: Avoiding the placement of amalgam and noble metal restorations in interproximal contact is recommended due to anticipated galvanic corrosion of the amalgam. There is a similar concern for amalgam/amalgam galvanic couples. It was the objective of this study to determine if an electrically insulating layer forms in the contact area of these galvanic couples.

Corrosion potential recovery of dental amalgam restorations following prophylaxis.

Objective: Dental amalgam restorations are subjected to abrasion during selective prophylaxis that can damage or remove the protective oxide and result in increased rates of corrosion and chemical dissolution of mercury. It was the objective of this research to study the corrosion potential change of dental amalgam restorations to obtain an indication of the time required for in vivo repassivation following prophylaxis.

Methods: The corrosion potentials of 27 Class I and Class II amalgam restorations were measured pre- and post-prophylaxis using a high impedance voltmeter and a Ag/AgCl micro-reference electrode.

Time-dependent corrosion potential of newly-placed admixed dental amalgam restorations.

Objective: It was the objective of this study to measure the corrosion potential over time of newly-placed admixed dental amalgam restorations as a possible indicator of corrosion activity.

Methods: The corrosion potentials of 271 amalgam restorations, 4-min to 24-month old were measured in a convenience sample of 81 subjects. The selected restorations had no occlusal or interproximal contact with other metallic restorations.

Corrosion potential variation of aged dental amalgam restorations over time.

Objective: The corrosion potential of a dental amalgam restoration is generally determined using a single measurement, even though environmental factors and abrasion can continuously alter the surface state and reactivity of this alloy. It was, therefore, the purpose of this study to determine the maximum variability of the corrosion potential of aged dental amalgam restorations, for 28 days.

Methods: The corrosion potentials of 148 aged dental amalgam restorations in 12 human subjects were measured at t = 0 and 4 h, and 4, 7, 14, 21 and 28 days.

In vivo galvanic currents of intermittently contacting dental amalgam and other metallic restorations.

Objective: It was the objective of this study to determine the magnitude of in vivo galvanic currents produced by simulating electrical contact between occluding metallic restorations, and to examine the influence of restoration age, difference in pre-contact corrosion potentials, and surface area.

Methods: A convenience sample of 106 human subjects was studied. A Ag/AgCl micro-reference electrode and a high impedance voltmeter were used to measure the pre-contact corrosion potentials.