Smoking produces an adverse effect on clinical periodontal variables and alveolar bone height and density, acting as a potential risk factor for alveolar bone loss, even at an early age with low tobacco consumption. It is very important to inform young smokers about the risk of this habit in relation to periodontal health.

The influence of emotional stress on the onset and control of bleeding episodes is a well-known fact. Oral surgical procedures are a common cause of severe states of anxiety in hemophiliacs. Anxiety has been shown to trigger and/or complicate an existing hemorrhagic episode in hemophiliacs. This is true in adults as well as children. Hypnosis, when applicable, has been found to be an excellent adjunct for the control of anxiety. It has been observed that in a relaxed and tranquil hemophiliac, his hemorrhagic tendency during and after surgery is considerably decreased. Induction to a hypnotic state depends on each individual's susceptibility, and therefore different approaches are used depending on the patient's knowledge of hypnosis. In addition to the control of fear, salivary secretions, pain, and capillary bleeding can well be brought under control during surgery and postoperatively by means of posthypnotic suggestions. Good oral hygiene habits such as daily brushing and flossing, so important as preventive measures for the prevention of caries and periodontal disease, can be reinforced through hypnotic suggestions. Preventive dentistry in hemophiliacs is of paramount importance.

The mechanisms by which endothelium attenuates vasodilation caused by isoflurane are not well understood. We examined the role of endothelium-derived substances, nitric oxide (NO), endothelium-derived hyperpolarizing factors (EDHF), prostanoids and endothelins in the response to isoflurane in rat thoracic aorta. Increasing cumulative concentrations of isoflurane were administered to aortic rings suspended in Hepes solution and preconstricted with either phenylephrine 10(-6) mol litre-1 or KCl 40 mmol litre-1 (which inhibit EDHF). Rings were intact, denuded or incubated with an inhibitor of nitric oxide synthesis (N omega-nitro-L-arginine (LNNA 5 x 10(-5) mol litre-1), an inhibitor of prostanoid synthesis (indomethacin 10(-5) mol litre-1) or a blocker of the vascular receptors to endothelins (cyclo (-D-trp-D-Asp-Pro-D-Val-Leu (BQ 123 10(-5) mol litre-1)- Endothelium attenuated isoflurane-induced vasodilation in KCl-constricted rings at concentrations of 4% (mean 95 (SEM 4)% vs 72 (4)%; P = 0.0005) and 5% (100 (4)% vs 80 (4)%; P = 0.0008) and in phenylephrine constricted rings at concentrations of 4% (54 (8)% vs 35 (3)%; P = 0.04) and 5% (78 (10)% vs 49 (5)%; P = 0.03). Relaxation was significantly greater in rings treated with LNNA than in intact rings at concentrations of 4% (85 (4)% vs 72 (4)%; P = 0.0005) and 5% (90 (4)% vs 80 (4)%; P = 0.0008). Indomethacin and BQ 123 did not alter isoflurane-induced vasodilation. We conclude that endothelium attenuated the vasodilator effect of isoflurane by a mechanism which was abolished by inhibition of nitric oxide. We hypothesize that isoflurane inhibits the release of nitric oxide, leading to a relative vasoconstriction counter-balancing its vasodilator effect. In contrast, EDHF, prostanoids and endothelins were not involved in the attenuation of isoflurane-induced vasodilatation.

Plasminogen activator in gingival tissue was histochemically identified using a fibrin filmslide technique. Microscopic examination clearly revealed the lytic areas induced in the fibrin background; therefore, they were topographically related to the overlaying gingival section, thus facilitating the localization of plasminogen activator in the gingival tissue. Fibrinolysis was observed only on the plasminogen‐rich fibrin clot; there was no activity in the plasminogen‐free fibrin clot. This is a clear indication that the lytic areas observed were due to activation of plasminogen by tissue activator and not due to other proteolytic enzymes. Lytic activity was always associated with blood vessels and the crevice area. The degree of activity was related to the time of incubation of the tissue section with the fibrin clot.