Dental students' knowledge and compliance in cross infection control procedures at a UK dental hospital

OBJECTIVES: To assess the knowledge and clinical practice of dental students in infection control procedures at a UK dental hospital.
DESIGN: A questionnaire concerning various aspects of infection control was completed by all clinical dental students under examination conditions. Their actual clinical practice was later observed and certain aspects recorded.
SETTING: A UK dental hospital.
SUBJECTS: One hundred and eleven dental students from three clinical years completed the questionnaire. Clinical practice for all 3 years was observed in a total of 280 treatment events.
METHODS: The questionnaire was marked by two of the authors and observations recorded by another author. MAIN OUTCOME MEASURES: Degree of compliance with recognised policy for infection control.
RESULTS: Knowledge of infection control procedures was variable particularly concerning duties usually undertaken by the dental nurse. The suggested high compliance with masks and eye protection was not always apparent in clinical practice, although virtually all students washed their hands prior to donning gloves, which were worn by all students.
CONCLUSION: There can be marked differences between what students say they would do and what they actually do in clinical practice. The topic of infection control requires a pro-active approach throughout the course, since results for the final year were not significantly different from the other clinical yearS. Ways of improving compliance are discussed.     

The effect of different bonding techniques on ceramic/ resin shear bond strength

PURPOSE: To investigate the effect of different adhesives on the shear bond strength between a feldspathic machinable ceramic and a luting resin. MATERIALS AND METHODS: Seven groups of 20 ceramic specimens each were machined from Vita Mark II blocs. Their surfaces were uniformly treated with 1000-grit paper. Group 1 (control) was hydrofluoric-acid etched for 60 s, group 2 abraded with CoJet, and group 3 PyrosilPen-treated and silanized. Groups 4 and 5 were hydrofluoric-acid etched for 60 s and silanized with two experimental silanes. Variolink II was used as the luting resin for groups 1 to 5. Group 6 and 7 were phosphoric-acid etched for 15 s. Then group 6 was treated with Nexus and group 7 with the Panavia F 2.0 system. All specimens were stored dry for 24 h at 37 degrees C. Shear bond strength was measured prior to and after 5000 thermocycles (TC) between 5 degrees C and 55 degrees C in water. ANOVA was performed with p < or = 0.05. RESULTS: Shear bond strength values 24 h / TC in MPa (SD) were as follows: group 1: 11 (3.0)/ 12 (5.3), group 2: 22 (3.9) / 25 (7.3), group 3: 26 (9.0) / 30 (8.0), group 4: 12 (5.9) / 8 (2.0), group 5: 8 (2.4) / 7 (3.4), group 6: 16 (6.1) / 3 (1.6) and group 7: 16 (8.6) / 16 (4.3). Cojet (24 h, p < or = 0.0007 / TC, p < or = 0.0001) and PyrosilPen (24 h, p < or = 0.0001/ TC, p < or = 0.0001) showed significantly higher bond strength than the control but did not differ significantly from each other. No significant differences between the control and groups 4, 5, 6, and 7 were found. PyrosilPen (p < or = 0.0001) significantly performed best prior to and after TC. Bond strength of experimental silane A (p < or = 0.0499) and Nexus (p < or = 0.0002) significantly decreased after TC. CONCLUSION: Silicoating technology and tribochemistry are fast, trouble-free, and effective surface treatment methods for achieving very good bond strength between feldspathic ceramics and luting resins. Etching with H2F2 can thus be avoided.     

Is there an association between anxiety/depression and temporomandibular disorders in college students?

Objective

Considering the high incidence of Temporomandibular Disorders (TMD) in the population aged 15-30 years and the fact that students are exposed to stressful psychosocial factors, the purposes of this study were: to verify clinical symptoms and jaw functionality in college students with TMD according to the anxiety/depression (A/D) level and to evaluate the correlation between A/D and functionality, maximum mouth opening (MMO) and pain and muscle activity.

Material and Methods

Nineteen students with TMD diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders underwent two assessments during an academic semester. The evaluations were based on questionnaires (MFIQ - Mandibular Function Impairment Questionnaire; HADS - Hospital Anxiety and Depression Scale), clinical measurements (MMO without pain, MMO and assisted MMO; palpation of joint and masticatory muscles), and electromyography. The HADS scores obtained in the two assessments were used to classify all data as either "high" or "low" A/D. Data normality, differences and correlations were tested with the Shapiro-Wilk test, Student''s t-test (or the Wilcoxon test), and Spearman test, respectively. The alpha level was set at 0.05.

Results

None of the clinical variables were significantly different when comparing low and high A/D data. In low A/D there was a significant correlation between HADS score and: MFIQ (P=0.005, r=0.61), and MMO without pain (P=0.01, r=-0.55).

Conclusions

Variation in A/D level did not change clinical symptoms or jaw functionality in college students with TMD. Apparently, there is a correlation between TMJ functionality and A/D level, which should be further investigated, taking into account the source of the TMD and including subjects with greater functional limitation.     

Anaphylaxis: an update for dental practitioners

Anaphylaxis is an acutely presenting life‐threatening medical emergency. Surveys indicate that dentists feel inadequately able to recognize and treat anaphylaxis. This paper reviews the terminology and pathophysiology of anaphylaxis, and describes the recognition and initial management of anaphylaxis for dentists. Dentists should be able to administer intramuscular adrenaline during anaphylaxis at the appropriate dose. The role of further medical care is also explained. Six cases of anaphylaxis arising from dental oral maxillofacial surgery practice are discussed.     

Reducing the duration of 100% oxygen ventilation in the early reperfusion period after cardiopulmonary resuscitation decreases striatal brain damage

Purpose

Previous data indicate that 100% O₂ ventilation during early reperfusion after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) increases neuronal death. However, current guidelines encourage the use of 100% O₂ during resuscitation and for an undefined period thereafter. We retrospectively analyzed data from a porcine CA model and hypothesized that prolonged hyperoxic reperfusion would be associated with increased neurohistopathological damage and impaired neurological recovery.

Methods

Fifteen male pigs underwent 8 min of CA and 5 min of CPR. After resuscitation animals were ventilated with either 100% oxygen for 60 min (hyperoxia; n = 8) or 10 min (normoxia; n = 7). Physiological variables were obtained at baseline and 10, 60 and 240 min after resuscitation. Daily functional performance was assessed using an established neurocognitive test in parallel to a neurological deficit score (NDS). On day 5, brains of the re-anaesthetized pigs were harvested for neurohistopathological analyses.

Results

At baseline there were no differences in hemodynamics and neurological status between groups. Post-arrest only PaO₂, as a result of the different inspired oxygen fractions, was significantly higher in the hyperoxia group.There was a numerical trend towards improved clinical recovery in both the NDS and the neurocognitive testing for animals exposed to 10 min of 100% oxygen. However, hyperoxic animals showed a significantly greater degree of necrotic neurons and perivascular inflammation in the striatum in comparison to normoxic animals.

Conclusion

In this retrospective analysis prolonged hyperoxia after CA aggravated necrotic brain damage and perivascular inflammation in the striatum of pigs.     

Elevated Plasma S100B,Psychotic Symptoms,and Cognition in Schizophrenia

S100B is a calcium binding protein mainly produced by glial cells. Previous studies have shown elevated levels of S100B in patients with schizophrenia. We measured S100B levels in fasting plasma of 39 patients with schizophrenia and 19 adult healthy controls. We used linear regression to compare S100B between patients and controls. In patients only, we also investigated the relationship between S100B levels and psychotic symptoms (assessed by the Positive and Negative Syndrome Scale), and cognitive function (assessed by the NIH Toolbox Cognition Battery), respectively by calculating Pearson’s correlation coefficients. Mean plasma S100B was significantly higher in the patient group than in the control group. There were no significant correlations between plasma S100B and psychotic symptoms or cognition.