Biomedical subjects

P J Lamey

Publications and source records attributed to P J Lamey.

At least 19 recordsLinked to original sources

PubMed2006

Shear bond strength and residual adhesive after orthodontic bracket debonding.

OBJECTIVE: To compare the shear bond strength and determine the area of residual adhesive on teeth after the debonding of brackets bonded with two types of orthodontic adhesives. These were a resin-modified glass ionomer cement (RMGIC; Fuji ORTHO LC, GC Corporation, Tokyo, Japan) and a resin applied as a precoated bracket (APC bracket, 3M Unitek GmbH, Seefeld, Germany). MATERIALS AND METHODS: A total of 60 premolar teeth were randomly divided into two groups, and brackets were bonded according to the manufacturers' instructions. In group 1, the teeth were conditioned using 10% polyacrylic acid, and the brackets were bonded using Fuji Ortho LC in wet condition. In group 2, the teeth were etched using 37% phosphoric acid, and the APC brackets were bonded. Bond strength was measured using a testing instrument (2000S, Lloyds Instruments, Fareham, England) at a crosshead speed of 1 mm/min, and the residual adhesive was quantified using a three-dimensional laser scanning instrument. RESULTS: The Mann-Whitney test showed that the median bond strength of group 1 was significantly lower than that of group 2 (P < .001). A Pearson chi-square test of the Adhesive Remnant Index (ARI) revealed a significant difference among the groups tested. All the adhesives in group 1 failed at the enamel/adhesive interface (100%), whereas group 2 exhibited cohesive failure of the adhesive (90%). CONCLUSIONS: The bond strength values obtained with the RMGIC were above the minimum values suggested in the literature to achieve a clinically effective adhesion in orthodontics.

Acid Etching, Dental↗

PubMed2006

Relationship between personality and satisfaction with the dentition in tooth wear patients.

This study was undertaken to identify whether personality traits had any relationship with patients' satisfaction with their dentition in tooth wear cases. One hundred tooth wear patients and one hundred controls were recruited into the study. A Dental Impact on Daily Living questionnaire was used to assess impact of tooth wear on day to day life and satisfaction with the dentition. An ordinal scale was used to assess tooth wear severity in tooth wear patients. The NEO Five Factor inventory was used to assess personal profiles. Tooth wear patients were less satisfied with their dentition, had higher Neuroticism, lower Extraversion, and higher Openness than the controls.

Activities of Daily Living↗

PubMed2003

Potentially malignant oral lesions in Northern Ireland: size (extent) matters.

OBJECTIVES: We examined clinical parameters of patients from Northern Ireland with potentially malignant lesions (PML) to determine association with development of intraoral squamous cell carcinoma (SCC). DESIGN: retrospective, cross-sectional, population-based, clinically validated, laboratory-verified. SUBJECTS AND METHODS: All patients who had more than one incisional oral mucosal biopsy diagnosed from 1975-1991 were abstracted from a database of all PML and SCC and their clinical records and biopsies reviewed. Patients were excluded if there was priorlsynchronous SCC or radiotherapy, frictional keratosis or lichen planus, missing clinical records/biopsy material or follow-up of <24 months. From the 50 suitable patients, gender, age, smoking status, site, clinical appearance and extent of lesion(s), treatment and year of diagnosis were recorded. Patients who developed SCC from PML were compared with those who did not. RESULTS: Squamous cell carcinoma occurred significantly more often in patients with single rather than multiple PML, those with 'non-homogenous' PML and in patients diagnosed prior to 1980. In Cox's survival analysis, only the clinical extent was predictive of SCC. CONCLUSIONS: Of all the features considered in our series, size (extent) was the most important clinical factor in determining the risk of future SCC in PML, particularly when several adjacent anatomical sites were affected.

Adolescent↗

PubMed2002

Quantitative analysis of substance P, neurokinin A and calcitonin gene-related peptide in pulp tissue from painful and healthy human teeth.

AIM: The purpose of this study was to investigate the levels of substance P (SP), neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) in painful and healthy human dental pulps. METHODOLOGY: Forty-six samples of pulp tissue were collected from extracted or endodontically treated painful teeth and 20 from clinically healthy teeth extracted for orthodontic reasons. All pulp samples were boiled in 0.5 m acetic acid for 10 min, centrifuged and the supernatant collected. SP, NKA and CGRP levels were measured using radioimmunoassay. RESULTS: Substance P and CGRP were present in all samples and NKA was detected in 96% of the pulps. CGRP was present in much higher concentrations than SP and NKA in both painful and non-painful teeth. The painful teeth had significantly higher concentrations of SP (P = 0.02), NKA (P < 0.001) and CGRP (P = 0.03) than non-painful teeth. The concentration of CGRP was significantly higher in the pulps of smokers compared with non-smokers (P = 0.02). CONCLUSIONS: Elevated levels of these neuropeptides in pulps from painful teeth indicate that they may play an important role in the process of pulpal inflammation and pain. Further investigation of the association between these neuropeptides and pulpal status may help to improve our understanding of pulpal inflammation and dental pain.

Adolescent↗

PubMed2002

Suprabasal p53 immunoexpression is strongly associated with high grade dysplasia and risk for malignant transformation in potentially malignant oral lesions from Northern Ireland.

AIMS: No good predictive marker for the malignant transformation of potentially malignant oral lesions (PMOLs) is currently available. This study re-evaluated the value of p53 immunoexpression to predict malignant transformation of PMOLs after discounting possible confounding factors. METHODS: PMOLs from 18 patients who showed progression to carcinoma, 16 of the respective carcinomas, and PMOLs from 18 matched controls were evaluated by immunohistochemistry (IHC) for p53 expression. A mouse monoclonal antibody that detects wild-type and mutant forms of human p53 was used. The p53 immunostaining pattern was also correlated with the degree of dysplasia. RESULTS: Suprabasal p53 staining was significantly associated with high grades of dysplasia (p < 0.01). The specificity and positive predictive value (PPV) for malignant transformation of suprabasal p53 staining were superior to the assessment of dysplasia, but sensitivity was inferior. All carcinomas derived from PMOLs with suprabasal p53 showed strong p53 immunostaining. However, the absence of suprabasal p53 staining and/or dysplastic changes did not preclude malignant transformation in a considerable proportion of PMOLs. CONCLUSIONS: This study confirms and extends previous findings that suprabasal p53 immunoexpression has a high PPV for malignant transformation of PMOLs and can be used as a specific marker for lesions that are at high risk for malignant transformation. The absence of suprabasal p53 staining (that is, absence of, or basal, p53 staining) is non-informative for prognostic purposes. Because of its limited sensitivity, p53 IHC is not a substitute for the assessment of dysplasia in the evaluation of PMOLs. Instead, p53 IHC emerges as a clinically useful supplement of histopathological assessment in the prognosis of PMOLs.

Adult↗

PubMed2001

Patients' pain experience following oral mucosal biopsy under local anaesthesia.

OBJECTIVE: To examine the incidence and severity of post-operative pain and use of analgesics following biopsy of oral mucosal lesions. DESIGN: A patient survey using a self-completed pain diary. SUBJECTS AND METHODS: Seventy-six patients attending an oral medicine clinic for investigation of oral mucosal disease recorded overall and worst pain experiences and analgesic usage over 7 post-operative days following biopsy using visual analogue scales in patient completed diaries. RESULTS: One third of patients reported no post-operative pain on any day. Most patients recorded no pain or mild pain. The percentage experiencing pain dropped from the first day (61%) to the seventh day (21%). Most patients did not use any analgesics. Analgesic use was not related to the presence of pain. Only a small minority of patients recorded severe pain. CONCLUSION: Biopsy of oral mucosal lesions does not cause undue pain in most patients.

Adolescent↗

PubMed2001

Quantitative analysis of MRP-8 in gingival crevicular fluid in periodontal health and disease using microbore HPLC.

BACKGROUND: The protein components of GCF can be separated by reverse-phase microbore HPLC on a C18 column with detection on the basis of 214 nm absorbance. A single major symmetrical protein peak eluting with a retention time of 26 min (50% acetonitrile) was evident in gingival crevicular fluid (GCF) from periodontitis patients but not in healthy GCF. This protein was identified as human MRP-8 by N-terminal amino acid sequencing and liquid chromatography quadropole mass spectrometry. AIMS: To quantify the amount of MRP-8 detectable in GCF from individual healthy, gingivitis and periodontitis affected sites and to study the relationship, if any, between the levels of this responsive protein and periodontal health and disease. METHODS: GCF was sampled (30 s) from healthy, gingivitis, and periodontitis sites in peridontitis subjects (n=15) and from controls (n=5) with clinically healthy gingiva and no periodontitis. Purified MRP-8 was sequenced by Edmann degradation and the phenylthiohydantoin (PTH) amino acid yield determined (by comparison of peak area with external PTH amino acid standards). This value was subsequently used to calculate the relative amount of protein in the peak eluting with a retention time of 26.0 min (MRP-8) in individual GCF chromatograms. RESULTS: Higher levels of MRP-8 were detected in inflammatory sites: periodontitis 457.0 (281.0) ng; gingivitis 413.5 (394.5) ng compared with periodontally healthy sites in diseased subjects 14.6 (14.3) ng and in controls 18.6 (18.5) ng, p=0.003. There was at least 20-fold more MRP-8 in the inflammatory compared with the healthy sites studied. CONCLUSIONS: The preliminary data indicate that MRP-8 is present in GCF, with significantly greater amounts present at diseased than healthy sites. A systematic study of the relationship of this protein to periodontal disease could prove useful in further clarifying whether MRP-8 could be a reliable GCF biomarker of gingivitis and periodontitis.

Adult↗

PubMed2001

The secretion of parotid saliva as stimulated by 10% citric acid is not related to precipitating factors in burning mouth syndrome.

Burning mouth syndrome (BMS) is known to have multiple precipitating factors and exists in various clinical subtypes. If salivary gland function was compromised in BMS it could help explain the link with diverse precipitating factors. This study quantified stimulated right and left parotid flow rates (SPFR) in 114 patients with BMS. It also attempted to correlate SPFR with haematinic parameters, oral candidal carriage, concurrent drug therapy and BMS subtype. No relationship was found between haematinic parameters and SPFR nor between SPFR and oral candidal carriage. Patients with Type 2 BMS had a significant reduction in SPFR. Antidepressant medication was associated with reduced SPFR but there was no such association with either tranquillisers or hypnotics. These results provide evidence of reduced parotid gland function in Type 2 BMS and a role for antidepressant medication in reducing SPFR.

Antidepressive Agents↗

PubMed2001

Migraine and masticatory muscle volume, bite force, and craniofacial morphology.

The purpose of this investigation was to compare the masticatory muscle volume, bite force, and craniofacial morphology of migrainous subjects with age- and sex-matched controls. Ten adult dentate migraineurs were matched with 10 dentate age- and sex-matched controls. The groups consisted of nine women and one man (mean age, 43 years; range, 29 to 51 years). Volumetric analysis of the masseter and medial pterygoid muscles was performed using magnetic resonance imaging. Craniofacial morphology was analyzed from standard cephalometric radiographs using 30 angular and linear variables. Recordings of bite force were made using a strain gauge transducer. There was a significant difference in the volume of both masseter and medial pterygoid muscles between the two subject groups (P<.0001), with the muscles of the migraineurs nearly 70% larger. The migraineurs recorded significantly higher maximal bite forces (P<.0001) than did the controls. No significant differences for any craniofacial morphological measurement were demonstrated between the two groups. It was concluded that the migraineurs had larger masseter and medial pterygoid muscle volumes, and greater bite forces than the controls, which could not be explained by any change in craniofacial morphology.

Adult↗

PubMed2001

The influence of antifungal drugs on virulence properties of Candida albicans in patients with diabetes mellitus.

OBJECTIVE: This study investigated the influence of nystatin and fluconazole on virulence properties of Candida albicans. STUDY DESIGN: A total of 108 diabetic patients participated in the study. Eighty-eight patients had clinical oral candidosis. Drug therapy was given at 6 hourly intervals for nystatin or daily with fluconazole for a maximum of 2 weeks. Adhesion of C albicans to buccal epithelial cells was determined by using an autologous adhesion assay prospectively over 6 months. Phospholipase production was estimated by using an agar plate method. The data analysis included a paired Student t test and calculation of correlation coefficients. RESULTS: Unlike nystatin, treatment with fluconazole reduced the ability of C albicans to colonize the buccal mucosa for up to 8 weeks after the treatment. Patients without clinical signs of oral candidosis had significantly fewer C albicans isolates producing phospholipase than did patients with oral candidosis. Treatment with fluconazole, but not nystatin, reduced the production of phospholipase from C albicans oral isolates in patients with diabetes mellitus. CONCLUSIONS: In addition to being antifungal, fluconazole alters phospholipase production, modifies buccal epithelial cells, and reduces adhesion of C albicans to human buccal epithelial cells for up to 8 weeks posttreatment in diabetic patients with oral candidosis.

Analysis of Variance↗

PubMed2001

Influence of psychological factors on the acceptance of complete dentures.

OBJECTIVES: To assess the influence of psychological factors on the acceptance of complete dentures in a population wearing dentures judged to be clinically satisfactory. DESIGN: Subjects were asked to complete personality profiles and also to rate their dentures using a denture satisfaction questionnaire. SETTING: The survey was conducted in the prosthetics clinic of a teaching hospital. SUBJECTS: Patients were selected from those who had new complete dentures constructed in the department within the previous two years. INTERVENTION AND MAIN OUTCOME MEASURES: The personality inventory was a self-administered questionnaire comprising 240 items covering the five domains of personality. Denture satisfaction was scored on a nine item scale with four Likert type responses to each. RESULTS: A group of 16% consistently complained about their dentures. Statistical analysis showed that personality factors especially Neuroticism had a significant relationship with denture satisfaction. CONCLUSION: Psychological factors significantly influence denture satisfaction and profiles may provide useful in predicting potential difficult denture wearers.

Aged↗

PubMed2000

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.

Adult↗

PubMed2000

Response to replacement iron therapy in sideropenic individuals with recrudescent herpes labialis.

This study investigated the effects of iron replacement on the incidence of recurrent herpes labialis and serum ferritin levels in patients with sideropenia. Ten patients with diagnosed sideropenia and a history of recrudescent herpes labialis were prescribed ferrous sulphate for a period of 3 months. Patients were questioned on the number of episodes of recrudescent herpes labialis that developed per month before treatment and the number of episodes of recrudescent herpes labialis that developed per month after the commencement of replacement iron therapy and during the follow-up period. All blood samples were collected by venipuncture for assay of ferritin levels. Serum ferritin levels were significantly increased compared to pretreatment levels (P<0.05). The number of monthly episodes of recrudescent herpes labialis was reduced from 0.78 to 0.2 episodes per month following treatment (P<0.05). The findings of this study suggest that iron replacement therapy should be further studied as a treatment option in sideropenic individuals with frequent recurrences of recrudescent herpes labialis.

Adolescent↗

PubMed2000

Carboxypeptidase-mediated metabolism of calcitonin gene-related peptide in human gingival crevicular fluid--a rôle in periodontal inflammation?

BACKGROUND: Metabolism by peptidases plays an important rôle in modulating the levels of biologically-active neuropeptides. The metabolism of the anti-inflammatory neuropeptide calcitonin gene-related peptide (GCRP), but not the pro-inflammatory neuropeptides substance P (SP) and neurokinin A (NKA) by components of the gingival crevicular fluid (GCF), could potentiate the inflammatory process in periodontitis. AIMS: To characterise the extracellular hydrolysis of CGRP as a mechanism for the selective inactivation of this neuropeptide in GCF from periodontitis sites. METHODS: Samples of GCF from periodontitis patients and periodontally-healthy subjects were incubated with synthetic human SP, NKA or CGRP. Reaction between the GCF constituents and synthetic peptides was allowed to progress from 0-180 min. Results of neuropeptide metabolism at each time were analysed by matrix-assisted laser desorption/ionisation mass spectrometry. RESULTS: There was no evidence of metabolism of SP, NKA or CGRP by constituents of healthy GCF. Metabolism of synthetic SP and NKA was minimal even after extensive incubation with periodontitis GCF. However, loss of carboxy-terminal amino acids was evident after only 1 min incubation with periodontitis GCF. The pattern of CGRP metabolism, which proceeded from the C-terminus, indicated that the neuropeptide was degraded by a carboxypeptidase. After 180 min, there was extensive carboxypeptidase degradation of CGRP to an 11 amino acid peptide. CONCLUSIONS: It is concluded that carboxypeptidase activity in GCF from periodontitis patients is responsible for rapid breakdown of CGRP but not SP or NKA. The rapid action of this carboxypeptidase on the anti-inflammatory neuropeptide CGRP is suggestive of a pathophysiological rôle for the enzyme in selectively degrading CGRP, thereby potentiating periodontal inflammation.

Adult↗

PubMed2000

Changes in substance P and neurokinin A in gingival crevicular fluid in response to periodontal treatment.

BACKGROUND: The study of periodontitis provides a unique model for assessing the involvement of neuropeptides in inflammatory disease. AIM: To investigate the effects of periodontal treatment, resulting in a return to periodontal health, on the levels of substance P (SP) and neurokinin A (NKA) in gingival crevicular fluid (GCF). METHOD: We completed a cause of non-surgical treatment for 8 subjects with periodontitis (6 females 2 males, mean age 45.1, range 38-67 years) started a course of non-surgical periodontal treatment. Clinical indices were measured at 2 periodontitis sites at the initial visit and at 8 weeks after the completion of treatment in each subject. A 30-s sample of GCF was collected from each test site using perio paper strips. Each strip was placed into 500 microl of ice cold 0.1 M PBS, pH 7.4, vortex mixed for 30 s, and then stored at -70 degrees C until analysed by radioimmunoassay. RESULTS: The clinical condition of all test sites improved as a result of the periodontal treatment. The levels (pg/30 s sample) of SP fell from 56.3 (SD 66.0) at the initial visit to 4.2 (3.1) after treatment, p=0.017. The concentration (pg/microl) of SP in GCF fell from 140.6 (175.6) to 24.2 (11.1), p=0.036. The levels of NKA fell from 30.5 (17.1) to 10.6 (4.9), p=0.012 whereas the concentration changed little from 85.4 (43.5) to 61.6 (15.1), p=0.41. CONCLUSION: The reduction in inflammation resulting from effective periodontal treatment is associated with a reduction in the levels of tachykinins in gingival crevicular fluid.

Adult↗

PubMed2000

Isolation of C. dubliniensis from insulin-using diabetes mellitus patients.

The identification of the novel candidal species, C. dubliniensis, from oral swab studies of HIV-seropositive and -seronegative individuals has led to speculation that such a species may also reside in the oral cavity of other patient groups. In this study involvement of the newly described species, C. dubliniensis, was investigated in oral carriage and disease in 414 insulin-using diabetes mellitus patients. Seventy-seven percent of the diabetic patients carried candidal species in the oral cavity. C. albicans was the most commonly identified candidal species. This was followed by C. dubliniensis, which was isolated on 64 occasions. Colonisation with multiple candidal species was common, and C. dubliniensis was present in both carriage and disease states. Seven patients without signs of oral disease had C. dubliniensis isolated as the sole candidal species, while the same species was associated with various forms of oral candidosis in six patients.

Candida↗

PubMed2000

Computerized infrared thermographic imaging and pulpal blood flow: Part 2. Rewarming of healthy human teeth following a controlled cold stimulus.

AIM: To investigate the rewarming pattern and rewarming rate of clinically healthy teeth following a controlled cold stimulus using TI techniques. METHODOLOGY: A controlled cold stimulus was developed using an air stream at 20 degrees C. Gingival and incisal sites on 12 healthy maxillary lateral incisors in six patients were imaged under rubber dam following 20 s cooling. Images were captured at 10 s intervals during a 3-min rewarming period and the data used to construct graphs of the rewarming rate. Log transformation of the data was used to produce 'best fit' straight line graphs. Linear regression analysis was used to examine three variables, viz. the side of the mouth (right or left), the site of measurement (gingival or incisal) and the phase of rewarming (early 0-90 s, late 91-180 s). RESULTS: The mean temperature change (delta t degree C) during rewarming was 8.5 degrees C (SD 1.0 degree C) for gingival sites and 7.2 degrees C (SD 1.1 degrees C) for incisal sites. The slope of the 'best fit' straight line data enabled a rewarming index to be calculated for each site on each tooth. Linear regression analysis showed that the phase of rewarming was highly significant but the other variables were not. A one-way ANOVA showed no significant differences between or within groups. CONCLUSIONS: Three min is an appropriate time to record rewarming of teeth cooled for 20 s with an airstream at 20 degrees C. The side or site used to record surface temperatures using this technique is not significant. Rewarming is exponential and log transformation of the data produces a well-fitting straight line graph. The slope of this line provides a rewarming index which should enable comparison of TI and laser Doppler flowmetry in determining pulpal blood flow as a measure of tooth vitality.

Adult↗

PubMed2000

Computerized infrared thermographic imaging and pulpal blood flow: Part 1. A protocol for thermal imaging of human teeth.

AIM: To observe the thermographic appearance of teeth and to develop a suitable protocol for imaging teeth in human subjects using modern thermographic imaging (TI) equipment in a thermologically controlled environment. METHODOLOGY: The emissivity of enamel was investigated using an extracted incisor tooth. A total of 12 unrestored maxillary lateral incisors in six healthy patients were then imaged under rubber dam after a 20-min equilibration period and the thermographic data analysed using a dedicated software package. Recordings were made from standardized gingival and incisal sites on each tooth and the temperature gradient established for each tooth. Subsequently, a sequence of images of both maxillary central incisors in one patient was stored every 30 s during a 20-min equilibration period with and without an air-conditioning unit in operation. RESULTS: For the lateral incisors there was a consistent temperature gradient (mean 1.28 degrees C) from gingival area to incisal area and there were no statistically significant differences between right and left sides for the gingival site (t = 0.34, NS) or the incisal site (t = 0.62, NS). The air-conditioning unit had a rapid and profound cooling effect. With the air-conditioning disabled there was a mean tooth surface temperature increase of 1.1 degrees C from 0 to 5 min of the equilibration period and 0.3 degree C from 15 to 20 min. CONCLUSIONS: There was no significant difference in gingival or incisal temperatures between pairs of contralateral maxillary lateral incisors and a consistent temperature gradient existed from gingival to incisal areas of healthy maxillary lateral incisor teeth. The protocol described is suitable for TI of vital teeth. However, TI measured tooth surface temperature only which was extremely sensitive to air currents. A 15-min acclimatization period under rubber dam was adequate to allow stable tooth surface temperature measurement.

Adolescent↗