[Control of cross-contamination in dental prostheses laboratories in Galicia]. / Control de la infección cruzada en los laboratorios de prótesis dental de Galicia.

BACKGROUND: Dental laboratories are a potential source of cross-contamination. This study aims to assess its control in Galicia. METHODS: Voluntary random telephone interviews resulted in 149 completed questionnaires. The variables are described by percentages or means and standard deviations. A bivariate analysis was undertaken using the Chi square test. RESULTS: Participants were mostly middle-age (mean=45.7, SD=9.8) males (68.5%) with 20.8 (SD=10.5) years of professional experience in middle-size urban (58.4%) laboratories, who identified a higher risk when receiving items from the clinic (80.6%). Most technicians (57.7%) have a written protocol. Many (55.0%), significantly older males, do not check for item disinfection. Most technicians use gloves (62.4%) particularly younger staff at larger laboratories. Fifty-five point seven percent had been vaccinated against hepatitis B. Only 22.0% of technicians reported receiving training in cross-contamination control. CONCLUSIONS: Identified cross-infection control practices are below standards, and lack of training and protocols are a matter for concern.

Changes in EMG activity during clenching in chronic pain patients with unilateral temporomandibular disorders.

The study assessed the differences in electromyographic (EMG) activity recorded during clenching in women with chronic unilateral temporomandibular disorders (TMDs) as compared to control subjects. Seventy-five full dentate, normo-occlusion, right-handed, similarly aged female subjects were recruited. Twenty five subjects presented with right side TMD, 25 presented with left side TMD and 25 pain-free control subjects participated. Using integrated surface EMG over a 1 s contraction, the anterior temporalis and masseter muscles were evaluated bilaterally while subjects performed maximum voluntary clenching. Lower EMG activation was observed in patients with TMD as compared to control subjects (temporalis: 195.74+/-18.57 vs. 275.74+/-22.11, P=0.011; masseters: 151.09+/-17.37 vs. 283.29+/-31.87, P<0.001). An asymmetry index (SAI) was calculated to determine ratios of right to left sided activation. Patients with right-sided TMD demonstrated preferential use of their left-sided muscles (SAI -5.35+/-4.02) whereas patients with left-sided TMD demonstrated preferential use of their right-sided muscles (SAI 6.95+/-2.82), (P=0.016). This unilateral reduction in temporalis and masseter activity could be considered as a specific protective functional adaptation of the neuromuscular system due to nociceptive input. The asymmetry index (SAI) may be a useful measure in discriminating patients with right vs. left-sided TMD.

Masseteric silent period in healthy young adults.

The length of the silent period (SP) has been subject of extensive researches and its use has been established for the diagnosis of dysfunctional individuals. Because of its great variability we should be cautious about its assessment. This study is aimed to find the normal values taken in symptomless subjects using a commercial/medical recording system, designed for clinical use. Thirty-six readings of the SP have been taken causing a chin tap. The assessment of the motor dysfunction and the subsequent depressed activity gave the result of 32.37 ms (SD = 19.47, ranged from 15 to 110). This is slightly more extended than the results described by the majority of the Authors.

A secure method for making removable dies.

Removable dies greatly facilitate fixed prosthesis fabrication and accurate marginal fit. The major difficulty when using removable dies is the correct positioning of the dowel pin in the stone base. This article describes a method for preparing removable dies that ensures accurate positioning of the dowel pin and provides external landmarks for precise location of the cuts to be made with the die saw. The method described is accurate, simple, inexpensive and can be performed in the dental laboratory.

[Anomalies of the inclination of the occlusal plane: early treatment using indirect guide-planes--electromyographic response]. / Anomalies d'inclinaison du plan occlusal: traitement précoce par les pistes indirectes--réponse électromyographique.

We discuss five cases of ANGLE's malocclusion Classes I, II or III that were rehabilitated basically by: restoration of masticatory function (previously pathological); the use of removable orthopaedic plates with indirect guideplanes. The patients (aged 6-15 years when treatment began) now have symmetrical balanced occlusion. Surface electromyography was used to study the function of the anterior temporal, surface masseter, deep masseter and anterior digastric muscles of 12 patients during rehabilitation of severe malocclusion. Electromyograms were obtained both with and without orthopaedic guideplanes installed. There were no significant differences as regards mean resting myoelectric activity. During maximum voluntary clenching in centric occlusion, the anterior temporal muscles were the most active, followed by the surface masseters. The activity of the anterior temporal muscles during clenching was significantly less (P < 0.01) with guideplanes than without. During lateral displacements, the non-working side anterior temporal muscle exhibited a significantly higher potential than the other muscles monitored, especially with guideplanes installed. The activity was lees with guideplanes during swallowing.