Influence of needle bevel design on injection pain and needle deformation in dental local infiltration anaesthesia - randomized clinical trial.

The aims of this in vivo study were to evaluate the impact of needle bevel design on patients' pain perception and the mechanical deformation of the needle tip after the injection. In a prospective single-blinded trial, 150 patients received conventional infiltration anaesthesia for dental treatment by one examiner. Patients were randomized for one out of three different needle bevel types (scalpel-designed bevel needle (SB), n=50; triple bevel needle (TB), n=50; regular bevel needle (RB), n=50). Subjects' self-reported injection pain perception was evaluated using a numeric rating scale (NRS). For each needle tip, deformations after single use were measured using SEM. A significant lower injection pain level was found in SB (mean 2.1±1.2) than in TB (mean 3.5±1.6;) and RB (mean 3.4±1.0; all P<0.001). A needle deformation was detected in about 97.3% of all needles (SB 50/50, TB 50/50, and RB: 46/50). A higher number of barbs were found in SB (29/50) versus TB (17/50) and RB (19/50). For dental local infiltration anaesthesia, injection needles with a scalpel-designed bevel demonstrated significantly less injection pain. Needle tip deflections after anaesthetic agent infiltration, especially barbed hooks on the non-cutting edge may result in greater soft tissue trauma.

Effects of exercise on swallowing and tongue strength in patients with oral and oropharyngeal cancer treated with primary radiotherapy with or without chemotherapy.

Tongue strength is reduced in patients treated with chemoradiotherapy for oral/oropharyngeal cancer. Tongue strengthening protocols have resulted in improved lingual strength and swallowing in healthy individuals, as well as in patients following a neurological event. However, no studies have examined the efficacy of tongue strengthening exercises on tongue strength, swallowing, and quality of life (QOL; Head and Neck Cancer Inventory) in patients treated with chemoradiotherapy. A randomized clinical trial examined the effects of a tongue strengthening programme paired with traditional exercises vs. traditional exercises alone. Dependent variables included tongue strength, swallowing, and QOL in a group of patients with oral and oropharyngeal cancer treated with primary radiotherapy with or without chemotherapy. Differences with regard to tongue strength and oropharyngeal swallow efficiency (OPSE) were not observed within or between groups. QOL in the eating and speech domains improved following treatment in both groups. However, the experimental group demonstrated greater impairment in QOL in the social disruption domain following treatment, whereas the control group demonstrated a slight improvement in functioning. Tongue strengthening did not yield a statistically significant improvement in either tongue strength or swallowing measures in this patient cohort. Patient compliance and treatment timing may be factors underlying these outcomes.

Advanced clinical technology--clinical tool or expensive toy?

There should no longer be any doubt in dentists' minds when it comes to the importance of technology in the day-to-day activities of the dental office. But there is, and this doubt must be addressed if the profession is to grow and prosper to its full potential. Denying the importance of technology--or putting on blinders--only leads to complacency, and clearly does not support our professions goal of providing the finest dental care possible. This article addresses the use of technology in a clinically-related manner, and attempts to provide the practitioner with valuable practice management tools to allow for a prosperous and efficient dental practice.

Spark erosion: a sophisticated technique to solve a difficult problem.

Even with the most careful planning, situations arise that require sophisticated treatment alternatives. The Milled Bar, of which the spark erosion bar is one type, is described in detail. A two-degree tapered meso (primary) bar with anterior friction pins attached to osseointegrated implants provides frictional retention when supporting a secondary bar with swivel lock attachments. The two components of the prosthesis are accurately associated with each other using spark erosion and plasma arc welding technology.

Evaluation of the safety of the carbon dioxide laser used in conjunction with root form implants: a pilot study.

This in vitro study was designed to test the safety of the CO2 laser when used around two different types of implant surfaces, hydroxyapatite-coated and commercially pure titanium, in a pig mandible. The implants were subjected to specific amounts of laser energy and then evaluated for temperature change at five different sites. The CO2 laser, when used at clinically applicable power densities of 2 and 4 watts in a continuous mode for up to 4 seconds, did not cause a temperature change in excess of 7 degrees F.

A simple gas chromatographic method for the analysis of trace organics in ambient air.

A simple method using adsorption, heat desorption, and F.I.D. gas chromatography to determine ppb quantities of various organic vapors in air is described. Laboratory results with chemicals such as bischloromethyl ether, vinyl chloride monomer and volatile ketones are discussed.