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.

A neotropical perspective on the uniqueness of the Holocene among interglacials

Understanding how tropical systems have responded to large-scale climate change, such as glacial-interglacial oscillations, and how human impacts have altered those responses is key to current and future ecology. A sedimentary record recovered from Lake Junín, in the Peruvian Andes (4085 m elevation) spans the last 670,000 years and represents the longest continuous and empirically-dated record of tropical vegetation change to date. Spanning seven glacial-interglacial oscillations, fossil pollen and charcoal recovered from the core showed the general dominance of grasslands, although during the warmest times some Andean forest trees grew above their modern limits near the lake. Fire was very rare until the last 12,000 years, when humans were in the landscape. Here we show that, due to human activity, our present interglacial, the Holocene, has a distinctive vegetation composition and ecological trajectory compared with six previous interglacials. Our data reinforce the view that modern vegetation assemblages of high Andean grasslands and the presence of a defined tree line are aspects of a human-modified landscape.

Did the UK's public health shielding policy protect the clinically extremely vulnerable during the COVID-19 pandemic in Wales? Results of EVITE Immunity, a linked data retrospective study

INTRODUCTION

The UK shielding policy intended to protect people at the highest risk of harm from COVID-19 infection. We aimed to describe intervention effects in Wales at 1 year.

METHODS

Retrospective comparison of linked demographic and clinical data for cohorts comprising people identified for shielding from 23 March to 21 May 2020; and the rest of the population. Health records were extracted with event dates between 23 March 2020 and 22 March 2021 for the comparator cohort and from the date of inclusion until 1 year later for the shielded cohort.

RESULTS

The shielded cohort included 117,415 people, with 3,086,385 in the comparator cohort. The largest clinical categories in the shielded cohort were severe respiratory condition (35.5%), immunosuppressive therapy (25.9%) and cancer (18.6%). People in the shielded cohort were more likely to be female, aged ≥50 years, living in relatively deprived areas, care home residents and frail. The proportion of people tested for COVID-19 was higher in the shielded cohort (odds ratio [OR] 1.616; 95% confidence interval [CI] 1.597-1.637), with lower positivity rate incident rate ratios 0.716 (95% CI 0.697-0.736). The known infection rate was higher in the shielded cohort (5.9% vs 5.7%). People in the shielded cohort were more likely to die (OR 3.683; 95% CI: 3.583-3.786), have a critical care admission (OR 3.339; 95% CI: 3.111-3.583), hospital emergency admission (OR 2.883; 95% CI: 2.837-2.930), emergency department attendance (OR 1.893; 95% CI: 1.867-1.919) and common mental disorder (OR 1.762; 95% CI: 1.735-1.789).

CONCLUSION

Deaths and healthcare utilisation were higher amongst shielded people than the general population, as would be expected in the sicker population. Differences in testing rates, deprivation and pre-existing health are potential confounders; however, lack of clear impact on infection rates raises questions about the success of shielding and indicates that further research is required to fully evaluate this national policy intervention.

UK national guidelines on the management of syphilis 2015

These guidelines are an update for 2015 of the 2008 UK guidelines for the management of syphilis. The writing group have piloted the new BASHH guideline methodology, notably using the GRADE system for assessing evidence and making recommendations. We have made significant changes to the recommendations for screening infants born to mothers with positive syphilis serology and to facilitate accurate and timely communication between the teams caring for mother and baby we have developed a birth plan. Procaine penicillin is now an alternative, not preferred treatment, for all stages of syphilis except neurosyphilis, but the length of treatment for this is shortened. Other changes are summarised at the start of the guideline.

The pattern of plasma sodium abnormalities in an acute elderly care ward: A cross-sectional study

INTRODUCTION

The combination of ageing, illness, and medications can lead to hyponatraemia or hypernatraemia.

AIMS

To describe the distribution of plasma sodium levels in older patients admitted to hospital.

METHODS

We carried out a hospital based cross-sectional study examining 1,511 serum sodium concentrations ([Na+]) among 336 elderly patients and attempted to elucidate the cause(s) of the abnormal serum [Na+].

RESULTS

The study population had a mean age of 81.4. Ninety-two (27.4%) patients had hyponatraemia and seven patients (2.1%) had hypernatraemia during their hospitalisation. The distribution of [Na+] results was towards the lower end of the normal range. The mortality rate of patients with hyponatraemia was 14.1% and that of patients with normal serum [Na+] was 8.9%. Six patients with hypernatraemia died in hospital. Lower respiratory tract infection and medication accounted for the majority of cases.

CONCLUSIONS

Deranged [Na+] is common among elderly patients admitted to hospital.

Challenges in implementing the new BASHH guidelines for the management of gonorrhoea

Neisseria gonorrhoeae has progressively developed reduced sensitivity to different classes of antibiotics. The British Association for Sexual Health and HIV (BASHH) updated guidelines for the diagnosis and management of gonorrhoea in 2011. New recommendations include an increased dose of ceftriaxone with adjuvant use of azithromycin, as well as test of cure (TOC) in all cases. We present an audit of adherence to new antibiotic prescribing guidelines as well as TOC uptake in an inner city genitourinary medicine clinic. Among the 271 (242 male, 29 female) patients included, 96% ( n = 260) received the new first-line treatment. Test of cure uptake was found to be suboptimal at 55% ( n = 149) with the majority (67%) of these taking place within 20 days of treatment. The new first-line treatment for gonorrhoea is feasible and generally accepted by patients. However the TOC uptake is low, emphasising the need for robust follow-up and recall policies. Further study is required into the optimal timing for TOC.

Are we forgetting the children? Testing the children of HIV-positive parents

Undiagnosed HIV infection in children carries significant risks and national guidelines recommend that children of HIV-positive parents be tested. We reviewed the testing of HIV-positive patients' children in those new to our service from April 2008 to December 2009. Of the 86 women, 95% were asked about children. Of the 243 men, 53 were heterosexual or bisexual, and 190 identified themselves as men who have sex with men (MSM). Parental status was determined in 37 (70%) of heterosexual and bisexual men and in 14 (17%) of 84 MSM with a history of previous female partners. All untested children apart from one lived in their country of origin. In MSM, recording of parental status was uncommon. Following this audit, clinic proformas were changed to document the parental status of men of all sexual orientations, and the HIV status of all children.

British Association for Sexual Health and HIV: framework for guideline development and assessment

This article has been prepared by the Clinical Effectiveness Group (CEG) of the British Association for Sexual Health and HIV (BASHH) to specify the methodology BASHH requires for guideline development and the process of guideline evaluation by the CEG. This replaces the specifications for the development of UK guidelines on the management of sexually transmitted infections and closely related conditions previously published in this journal in 2004 and updated in 2005.

Management of pyrexia of unknown origin in HIV-positive patients

Recently, we managed the case of a young HIV-positive man with a pyrexial illness and severe constitutional symptoms, the cause of which was elusive for several weeks. Here we review the causes of pyrexia of unknown origin in HIV-positive individuals, review appropriate investigations and discuss possible empirical treatment when this is required.

Documentation of advice regarding safer sexual practices and partner notification within an HIV clinic

Guidelines for the sexual health care of our HIV patients and provision of post-exposure prophylaxis following sexual exposure have been produced by both British Association of Sexual Health & HIV and British HIV Association (BHIVA). In the light of recent criminal prosecutions, BHIVA produced guidance for HIV clinical teams regarding discussions with patients about HIV transmission and reducing the risk to sexual partners. This audit examined the advice given to HIV patients with regard to safer sexual practices, sexually transmitted infection screening and partner notification and found that, on the whole, the standards set by national guidelines were adhered to, although areas for improvement were identified. We hope that the introduction of proformas with specific prompts for these subjects for HIV clinic visits will improve clinical standards in this area.

Determining the professional attributes of a hospitalist: experience in one Australian metropolitan hospital

Data were prospectively recorded on 1294 consecutive patients admitted to a General Medical Unit at the Gold Coast Hospital to review the caseload and pre-requisite professional skills of a general physician working as a full-time hospitalist. Based on this review, the general physician hospitalist must possess expertise in the management of common medical conditions and comorbidities, uncommon medical conditions, elderly patients, the seriously ill, the terminally ill, psychiatric patients, surgical patients and patients with dermatologic, ophthalmic and gynaecological problems. The hospitalist must also be proficient in medical education and organization governance. The demonstration of such skills ensures the 'hospitalist' model is efficient and effective for hospital-based care.

Antibiotic prescribing policy and Clostridium difficile diarrhoea

BACKGROUND

Broad-spectrum antibiotics, particularly intravenous cephalosporins, are associated with Clostridium difficile diarrhoea. Diarrhoea due to C. difficile is a growing problem in hospitals, especially among elderly patients.

AIM

To establish whether changing an antibiotic policy with the aim of reducing the use of injectable cephalosporins leads to a reduction in the incidence of C. difficile diarrhoea in elderly patients.

DESIGN

Retrospective analysis.

METHODS

A group of patients who were subject to the new antibiotic policy from the period following July 2000, were compared with patients who were admitted prior to July 2000 and were not subject to the new policy. Infections, antibiotic prescriptions and mortality rates were determined from case notes, and C. difficle diarrhoea rates from microbiological data.

RESULTS

Intravenous cephalosporin use fell from 210 to 28 defined daily doses (p < 0.001) following the change in antibiotic policy, with a corresponding increase in piperacillin-tazobactam (p < 0.001) and moxifloxacin (p < 0.001) use. The new policy led to a significant reduction in C. difficile diarrhoea cases. The relative risk of developing C. difficile infection with the old policy compared to the new policy was 3.24 (95%CI 1.07-9.84, p = 0.03).

DISCUSSION

The antibiotic policy was successfully introduced into an elderly care service. It reduced both intravenous cephalosporin use and C. difficile diarrhoea.

Temporal sensitivity of bovine embryos to culture environment after fertilization and the implications for blastocyst quality

The aim of this study was to examine the temporal sensitivity of bovine embryos to culture environment after fertilization to determine which period, if any, is most critical in determining blastocyst quality. Bovine zygotes produced in vitro were divided into six groups and cultured either in vitro (in synthetic oviductal fluid, SOF), in vivo (in the ewe oviduct) or in a combination of both systems. Development to the blastocyst stage, the ability of the blastocysts to withstand cryopreservation and the relative abundance of several gene transcripts were examined. Culture in SOF for either 2 or 4 days, followed by subsequent culture in the ewe oviduct, resulted in a significantly lower yield of blastocysts than did all other methods, the effect being most marked in embryos that were cultured in SOF for 4 days. In contrast, culture in vivo for the first 2 or 4 days after fertilization followed by culture in vitro did not have such a marked effect on blastocyst development. Blastocysts produced after culture in the oviduct for 6 days had the highest rates of survival over 72 h after warming (100% survival at 24 h; >95% survival at 72 h). The embryos that spent the last 4 days of culture in vivo also had relatively high rates of survival (100% at 24 h, 73.7% at 72 h). Blastocysts produced entirely in SOF had very low rates of survival after vitrification, with <40% viable at 24 h and <20% survival at 72 h. Blastocysts derived from embryos that spent the first 2 days in vivo and the last 4 days in vitro had the lowest rates of survival (6.7%), whereas those that spent the last 2 days only in SOF had intermediate rates of survival (40.6%). These differences were reflected in the relative abundance of transcripts for the Bax gene.

Temporal sensitivity of bovine embryos to culture environment after fertilization and the implications for blastocyst quality

The aim of this study was to examine the temporal sensitivity of bovine embryos to culture environment after fertilization to determine which period, if any, is most critical in determining blastocyst quality. Bovine zygotes produced in vitro were divided into six groups and cultured either in vitro (in synthetic oviductal fluid, SOF), in vivo (in the ewe oviduct) or in a combination of both systems. Development to the blastocyst stage, the ability of the blastocysts to withstand cryopreservation and the relative abundance of several gene transcripts were examined. Culture in SOF for either 2 or 4 days, followed by subsequent culture in the ewe oviduct, resulted in a significantly lower yield of blastocysts than did all other methods, the effect being most marked in embryos that were cultured in SOF for 4 days. In contrast, culture in vivo for the first 2 or 4 days after fertilization followed by culture in vitro did not have such a marked effect on blastocyst development. Blastocysts produced after culture in the oviduct for 6 days had the highest rates of survival over 72 h after warming (100% survival at 24 h; >95% survival at 72 h). The embryos that spent the last 4 days of culture in vivo also had relatively high rates of survival (100% at 24 h, 73.7% at 72 h). Blastocysts produced entirely in SOF had very low rates of survival after vitrification, with <40% viable at 24 h and <20% survival at 72 h. Blastocysts derived from embryos that spent the first 2 days in vivo and the last 4 days in vitro had the lowest rates of survival (6.7%), whereas those that spent the last 2 days only in SOF had intermediate rates of survival (40.6%). These differences were reflected in the relative abundance of transcripts for the Bax gene.

The use of clinical measures in the Lidcombe Programme for children who stutter

This paper aims to demonstrate how the speech measures which are collected to inform the therapy process also have the potential to evaluate clinical change and effectiveness. Certain methodological issues pertinent to evaluating therapy for early stuttering are raised and the clinical measures that are a part of the Lidcombe Programme (Onslow 1993) are discussed in relation to these. Reference to a single case study is made to demonstrate how the measures contribute to clinical decision-making. Some initial results of the authors' use of the Lidocombe Programme in the UK is outlined.

The antidiabetic activity of aloes: preliminary clinical and experimental observations

The dried sap of the aloe plant (aloes) is one of several traditional remedies used for diabetes in the Arabian peninsula. Its ability to lower the blood glucose was studied in 5 patients with non-insulin-dependent diabetes and in Swiss albino mice made diabetic using alloxan. During the ingestion of aloes, half a teaspoonful daily for 4-14 weeks, the fasting serum glucose level fell in every patient from a mean of 273 +/- 25 (SE) to 151 +/- 23 mg/dl (p less than 0.05) with no change in body weight. In normal mice, both glibenclamide (10 mg/kg twice daily) and aloes (500 mg/kg twice daily) induced hypoglycaemia after 5 days, 71 +/- 6.2 and 91 +/- 7.6 mg/dl, respectively, versus 130 +/- 7 mg/dl in control animals (p less than 0.01); only glibenclamide was effective after 3 days. In the diabetic mice, fasting plasma glucose was significantly reduced by glibenclamide and aloes after 3 days. Thereafter only aloes was effective and by day 7 the plasma glucose was 394 +/- 22.0 versus 646 +/- 35.9 mg/dl, in the controls and 726 +/- 30.9 mg/dl in the glibenclamide treated group (p less than 0.01). We conclude that aloes contains a hypoglycaemic agent which lowers the blood glucose by as yet unknown mechanisms.

Hepatic tumors in Saudi Arabia. A practical approach to diagnosis

All cases of liver tumor referred to the King Faisal Specialist Hospital and Research Centre in Saudi Arabia during 2.5 years were reviewed. Hepatocellular carcinoma, 104 cases, was considerably more common than metastatic carcinoma with unknown primary, 15 cases. Lymphoma presenting as liver tumor occurred in three cases and there were no cases of cholangiocarcinoma. There were only two cases of benign tumor, both hemangioma. Hepatocellular carcinoma was characterized by a male predominance of 6:1, positive hepatitis B surface antigen in 60%, presentation with an enlarged, hard liver in over 90%, a systolic-diastolic bruit over the mass in 45%, a single highly echogenic lesion in the right lobe on ultrasound in 80%, and rapid progression. The serum AST (aspartate aminotransferase, serumglutamic oxalacetic transaminase [SGOT]) was abnormal in 97% and was higher than the alanine aminotransferase (ALT) in 93% of cases compared with 17% in 100 consecutive cases of chronic active hepatitis. Sixty-six percent of patients with hepatocellular carcinoma had serum AFP greater than 200 ng/ml. Excluding five cases of germ cell tumor (none involving the liver), and pregnant patients, serum AFP was less than 200 ng/ml in all other patients in whom it was measured between 1979 and 1981. A practical approach to the diagnosis of hepatocellular carcinoma is outlined. Biopsy does not appear to be indicated in many cases of advanced hepatocellular carcinoma.

Treatment of severe hypophosphatemia

A 4-h infusion of 310 to 465 mg (10 to 15 mMol) phosphorus given to 28 of 31 consecutive seriously ill hypophosphatemic patients increased the serum phosphorus level above 1.2 mg/dl in all but one patient. There was no significant change in the mean serum calcium, potassium or blood pressure, no patient deteriorated, and six patients were stronger and more alert after the infusion. In seriously ill patients we recommend a 4-h infusion of 15 mg/kg (0.5 mMol/kg) phosphorus if the serum phosphorus is less than 0.5 mg/dl, or a 7.7-mg/kg (0.25 mMol/kg) infusion if the serum phosphorus is between 0.5 and 1.0 mg/dl.

Aneurysm after arterial puncture in Behçet's disease

Images