Philip-John Lamey

The relationship between colonisation, secretor status and in-vitro adhesion of Candida albicans to buccal epithelial cells from diabetics

This study investigated whether oral candida infection in diabetics and adhesion of Candida albicans to buccal epithelial cells in vitro were related. Buccal cells from 50 patients with diabetes mellitus showed a significant increase in adhesion of C. albicans strain CDS 88 compared with those collected from 50 non-diabetic controls matched for age, sex and denture status. Oral candida carriage, candida infection and secretor status were also investigated in both groups. The frequency of carriage was increased, but not significantly, and there was a significantly higher incidence of candida infection in diabetic patients compared with controls. Diabetic patients who were non-secretors had a significantly increased frequency of oral candida carriage.

Oral candidal carriage and infection in insulin‐treated diabetic patients

Aim To evaluate candidal load and carriage of candidal species in 414 insulin‐treated diabetes mellitus patients with and without clinical signs of infection. Host factors that could influence candidal load in diabetic patients with oral candidosis were also investigated.

Thermographic measurement of temperature change during resin composite polymerization in vivo

OBJECTIVES To use the technique of infrared thermography for non-invasive monitoring of temperature changes during polymerization of resin composite by measuring the infra-red emission from the surfaces of resin composite restorations during photocuring. METHODS In this study 10 patient volunteers had resin composite restorations placed in upper incisor teeth and during photocuring the temperature rise within the composite was measured using the Thermovision 900 infra-red scanning system. RESULTS The results demonstrate that the exotherm is almost instantaneous, occurring as soon as the light source is activated and rising to a peak at approximately 30 s before levelling off. The measurements suggest that a maximum temperature increase of 12 degrees C could occur, although this may only be for a short period (< 15 s). CONCLUSION The range of temperature rise measured in this study (mean 5.4 degree C +/- 2.5 degree C) would suggest that the pulp may be endangered by the temperature rise which occurs during resin composite polymerization in vivo.

Oral Disorders Associated with Diabetes Mellitus

The protean manifestations of diabetes include various associated oral disorders such as sialosis, xerostomia, impairment of taste, and localized infections of which oral candidosis is the most commonly observed. The association of specific oral diseases and diabetes is of importance both in the detection of undiagnosed diabetes and in the elucidation of the pathogenesis of various oro‐facial diseases. The clinical features and possible causes of oral disorders recognized to be associated with diabetes are reviewed with emphasis on good oral hygiene in the diabetic patient.

Identification and overexpression of human neutrophil α-defensins (human neutrophil peptides 1, 2 and 3) in squamous cell carcinomas of the human tongue

To date, little attention has been paid to the possible role of alpha-defensins (human neutrophil peptides 1-3), HNP-1, HNP-2 and HNP-3 in innate host defence against tumour invasion. In the current study, using a single-dimensional high pressure liquid chromatography (HPLC) method for peptide separation, followed by mass spectrometry and amino acid sequencing for identification and quantitation, we report the overexpression of HNP-1, HNP-2 and HNP-3 in squamous cell carcinomas of the human tongue compared with autogenous non-tumour tissue. Using a specific antibody we show that the defensins are abundant in neutrophils infiltrating human oral squamous cell carcinoma tissue. In the context of their previously reported oncolytic activity, our results may imply a role for alpha-defensins in host defence against oral squamous cell carcinoma.

Management of potentially malignant oral mucosal lesions by consultant UK oral and maxillofacial surgeons

This paper describes the results of a recent survey carried out under the auspices of the Professional Education and Evaluation Subgroup of the UK Working Group on Screening for Oral Cancer and Precancer. The aim of this survey was to assimilate information regarding currently used management options of potentially malignant oral lesions as a basis from which to rationalise our future approach to their management. The survey has confirmed that variation exists among oral and maxillofacial consultants in their approaches and a more formal approach to management may therefore be indicated.

Unusual leiomyomatous hamartoma of the hard palate

Harmartomas of the head and neck are common lesions, often taking the form of melanocytic nevi or vascular malformations such as hemangiomas and lymphangiomas. Hamartomas composed of other tissue types are much rarer and within the oral cavity are usually located on the tongue near the foramen cecum or on the anterior hard palate near the incisive papilla. Although most occur as isolated phenomena, a small number may be associated with other local developmental defects or with a syndrome complex. A normal 5-year-old girl had a 1 cm soft sessile swelling in the vault of the hard palate on the left side. Histopathologic examination showed bundles of smooth muscle embedded in fibrovascular stroma and accompanied by abundant mature fat and a small amount of salivary tissue. The features were regarded as those of a leiomyomatous hamartoma and could be distinguished from a smooth-muscle tumor, teratoma, and benign mesenchymoma by virtue of the clinical and histopathologic features. No recurrence has been seen after excision.

Identification of MRP-8 (calgranulin A) as a major responsive protein in chronic periodontitis

The purpose of the study was to analyse how the protein composition of the inflammatory exudate associated with chronic periodontitis differed from the exudate in periodontal health. Gingival crevicular fluid (GCF) was collected from sites with chronic periodontal inflammation and from non‐diseased sites in healthy control subjects. Microbore HPLC analysis revealed one major difference in GCF protein profiles between healthy controls and periodontitis patients. The protein enhanced in periodontitis patients was identified as migration inhibitory factor‐related protein‐8 (MRP‐8) by a combination of N‐terminal amino acid sequencing, mass spectrometry, and SDS‐PAGE. Together, these data demonstrate, for the first time, the presence of monomeric MRP‐8 in an inflammatory exudate. Whether monomeric MRP‐8 is a unique feature of chronic periodontal inflammation is not yet clear, but the chemotactic properties of this peptide support a functional role for MRP‐8 in periodontal inflammation. Copyright

Quantification of tooth wear: Conventional vs new method using toolmakers microscope and a three-dimensional measuring technique

OBJECTIVES This study aimed to evaluate the reliability of a new CAD-CAM Laser scanning machine in detection of incisal tooth wear through a 6-month period and to compare the accuracy of using this new machine against measuring tooth wear using tool maker microscope and conventional tooth wear index. METHODS Twenty participants (11 males and 9 females, mean age=22.7 years, SD=2.0) were assessed for incisal tooth wear of lower anterior teeth using Smith and Knight clinical tooth wear index (TWI) on two occasions, the study baseline and 6 months later. Stone dies for each tooth were prepared and scanned using the CAD-CAM Laser Cercon System (Cercon Smart Ceramics, DeguDent, Germany). Scanned images were printed and examined under a toolmaker microscope (Stedall-Dowding Machine Tool Company, Optique et Mecanique de Precision, Marcel Aubert SA, Switzerland) to quantify tooth wear and then the dies were directly assessed under the microscope to measure tooth wear. The Wilcoxon Signed Ranks Test was used to analyse the data. RESULTS TWI scores for incisal edges were 0, 1, and 2 and were similar at both occasions. Scores 3 and 4 were not detected. Wear values measured by directly assessing the dies under the tool maker microscope (range=517-656microm, mean=582microm, and SD=50) were significantly more than those measured from the Cercon digital machine images (range=132-193microm, mean =165microm, and SD=27) and both showed significant differences between the two occasions. CONCLUSIONS Measuring images obtained with Cercon digital machine under tool maker microscope allowed detection of wear progression over the 6-month period. However, measuring the dies of worn dentition directly under the tool maker microscope enabled detection of wear progression more accurately. Conventional method was the least sensitive for tooth wear quantification and was unable to identify wear progression in most cases.

Neuropeptide Y Y1 receptor in human dental pulp cells of noncarious and carious teeth.

AIM To determine the distribution of the NPY Y1 receptor in carious and noncarious human dental pulp tissue using immunohistochemistry. A subsidiary aim was to confirm the presence of the NPY Y1 protein product in membrane fractions of dental pulp tissue from carious and noncarious teeth using western blotting. METHODOLOGY Twenty two dental pulp samples were collected from carious and noncarious extracted teeth. Ten samples were processed for immunohistochemistry using a specific antibody to the NPY Y1 receptor. Twelve samples were used to obtain membrane extracts which were electrophoresed, blotted onto nitrocellulose and probed with NPY Y1 receptor antibody. Kruskal-Wallis one-way analysis of variance was employed to test for overall statistical differences between NPY Y1 levels in noncarious, moderately carious and grossly carious teeth. RESULTS Neuropeptide Y Y1 receptor immunoreactivity was detected on the walls of blood vessels in pulp tissue from noncarious teeth. In carious teeth NPY Y1 immunoreactivity was observed on nerve fibres, blood vessels and inflammatory cells. Western blotting indicated the presence and confirmed the variability of NPY Y1 receptor protein expression in solubilised membrane preparations of human dental pulp tissue from carious and noncarious teeth. CONCLUSIONS Neuropeptide Y Y1 is expressed in human dental pulp tissue with evidence of increased expression in carious compared with noncarious teeth, suggesting a role for NPY Y1 in modulation of caries induced pulpal inflammation.