The Effect of Water Coolant and Bur Type on Pulp Temperature When Removing Tooth Structure and Restorative Dental Materials.

OBJECTIVE: The aim was to compare intrapulp temperature (IPT) changes when flat-fissure diamond burs and pear-shaped tungsten carbide burs were used to cut tooth structure, amalgam, and composite resin with and without water coolant. METHODS: Thermocouples were inserted into the pulp chamber of extracted intact mandibular molars. The thermocouples were connected to an electronic thermometer that detects temperature every second to an accuracy of 0.1°C. IPT changes were recorded while using a high-speed handpiece during MOD cavity preparations (n=40), composite resin removal (n=40), and amalgam removal (n=40). A two-way ANOVA was used for each procedure to test for the effect of bur (pear-shaped tungsten carbide vs flat-fissured diamond) and water coolant (on vs off), with significant main effects (α=0.05) further analyzed using Tukey's multiple comparison test. RESULTS: During MOD cavity preparation, water coolant reduced changes in IPT (0.03±0.27°C) compared to no water coolant (1.27±0.29°C) when tungsten carbide burs were used (p<0.05) but not when diamond burs were used. During composite resin removal, tungsten carbide burs had less changes in IPT (0.55±0.18°C) compared to diamond burs (1.66±0.50°C) with no water coolant (p<0.05). Water coolant also reduced changes in IPT (0.09±0.14°C) compared to no water coolant (1.66±0.50°C) when diamond burs were used (p<0.01). Water coolant did not significantly affect IPT when tungsten carbide burs were used. During amalgam removal, tungsten carbide burs had lower changes in IPT (0.56±0.15°C) compared to diamond burs (1.88±0.43°C) with no water coolant (p<0.05). Water coolant also significantly reduced changes in IPT (0.71±0.2°C) compared to no water coolant (1.88±0.43°C) when diamond burs were used (p<0.05) but not when tungsten carbide burs were used. CONCLUSIONS: Water coolant reduced IPT changes when drilling tooth structure with tungsten carbide burs, but not when removing amalgam or composite. Conversely, water coolant reduced IPT changes when drilling with flat fissure diamond burs to remove amalgam and composite, but not when removing tooth structure. When amalgam and composite were removed without water coolant, the tungsten carbide burs resulted in lower IPT changes than when flat fissure diamond burs were used in the same way.

Improvements in health-related quality of life with sumatriptan treatment for migraine.

BACKGROUND: The debilitating effects of migraine might be reduced in patients using an effective migraine medication. The serotonin (5HT1) receptor agonist sumatriptan has been shown in clinical trials to alleviate headache and associated symptoms in the majority of patients treated. METHODS: Three hundred forty-four (344) patients with migraine were allowed to treat an unlimited number of migraine attacks for up to 24 months with subcutaneous sumatriptan (6 mg). Open-label oral sumatriptan (100 mg) could be used between 1 hour and 24 hours after the initial injection for treatment of recurrent or persistent headache. On four occasions during the treatment period, patients completed the Medical Outcomes Study Short Form-36 Health Survey, a general health status instrument; the Migraine-Specific Quality of Life Questionnaire, a disease-specific instrument; and a series of questions designed to measure the impact of migraine on productivity and disability. RESULTS: Treatment with sumatriptan was associated with significant (P < .05) improvements relative to baseline in three of the Short Form-36 Health Survey quality-of-life dimensions (Bodily Pain, General Health Perceptions, and Social Functioning) and three of the Migraine-Specific Quality of Life Questionnaire dimensions (Role Function-Restrictive, Role Function-Preventive, and Emotional Function). Significant (P < .05) improvements in patient-rated productivity and reductions in patient-rated disability also occurred during the trial. CONCLUSIONS: Patients using sumatriptan to treat migraines for up to 24 months experienced improvements in disability and productivity as well as in health-related quality of life as measured either by a general health status instrument or a disease-specific instrument.

In vitro embryonation of Syphacia obvelata eggs.

Mouse infections with the pinworm, Syphacia obvelata, were evaluated as a potential model of human enterobiasis. Eggs of S. obvelata were found to be much less resistant to adverse environmental factors than those of Enterobius vermicularis, perishing rapidly when exposed to desiccation or to water. The average number of eggs produced by a female worm was 317 +/- 29 S.D. (range: 266-347), which is about 2-3% of the fecundity of E. vermicularis. Eggs expressed from gravid S. obvelata were incubated under various conditions, but the only reliable method of supporting complete embryonation was culture on a floating cellophane membrane. At 30 degrees C on this substrate, eggs were found to be infective between 6 and 42 h, inclusive. The pre-patent period in mice fed these eggs was 11-15 days. The more fastidious developmental and survival requirements of Syphacia eggs indicate that transmission of this species depends on much more intimate contact between hosts than is required by E. vermicularis.