Influence of Mechanical Cycling on Torque Values of Tapped-In and Screw-In Implant-Supported Crowns.

This study investigated the influence of mechanical cycling on screwed-in and tappedin implants restored with screw-retained metallic crowns. Three implant-abutmentcrown systems were evaluated: T1 (multi abutment) and T2 (standard abutment) received tapped-in abutments and S received a screwed-in abutment. The specimens were subjected to two million cycles of 0-150 N load, at 2 Hz, 30° inclination in a dry medium, and torque evaluation. Survival and removal torque were analyzed using chisquare, ANOVA, followed by Tukey's test. Differences between installation and removal torque were determined using a T-test for dependent samples. Analyses were performed in SPSS, considering α = 0.05. All specimens survived mechanical cycling in S, 40% in T1, 80% in T2 (p=0.008). Failures occurred due to loosening of the crown screw. A significant decrease in torque (p=0.000) was found. Group T1 had the lowest removal torque (1.6 ± 0.84 N.Cm²), followed by T2 (3 ± 1.49 N.Cm²) and S (6.3 ± 1.16 N. Cm²), and a statistical difference was found between Groups T1 and S. Both types of implantabutment connections were stable and can be considered for rehabilitative treatment, but failure and removal torque were influenced by the design of prosthetic abutment. Crowns were more susceptible to becoming loose in tapped-in systems.

Food allergy and infantile autism.

The etiopathogenesis of infantile autism is still unknown. Recently some authors have suggested that food peptides might be able to determine toxic effects at the level of the central nervous system by interacting with neurotransmitters. In fact a worsening of neurological symptoms has been reported in autistic patients after the consumption of milk and wheat. The aim of the present study has been to verify the efficacy of a cow's milk free diet (or other foods which gave a positive result after a skin test) in 36 autistic patients. We also looked for immunological signs of food allergy in autistic patients on a free choice diet. We noticed a marked improvement in the behavioural symptoms of patients after a period of 8 weeks on an elimination diet and we found high levels of IgA antigen specific antibodies for casein, lactalbumin and beta-lactoglobulin and IgG and IgM for casein. The levels of these antibodies were significantly higher than those of a control group which consisted of 20 healthy children. Our results lead us to hypothesise a relationship between food allergy and infantile autism as has already been suggested for other disturbances of the central nervous system.