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Biomedical subjects

H N Newman

Publications and source records attributed to H N Newman.

At least 37 records · Page 2Linked to original sources
PubMed2000

Comparison of clinical outcomes following treatment of chronic adult periodontitis with subgingival scaling or subgingival scaling plus metronidazole gel.

BACKGROUND, AIMS: Conventional treatment of chronic periodontitis involves mechanical debridement of periodontal pockets. Recently, subgingival antimicrobials have been used adjunctively following such debridement. This 2-centre study compared the clinical effects of subgingival scaling (SRP) with SRP plus subgingival application of 25% metronidazole gel, Elyzol (SRP+gel), in patients with chronic adult periodontitis. METHOD: Voluntary informed written consent was obtained from 45 subjects at the Eastman (mean age 46, range 34-63) and 43 subjects at RAF Halton (mean age 47, range 34-71) who participated in this blind, randomised split-mouth design study. All had at least 2 sites in each quadrant with probing pocket depth (PPD) > or = 5 mm. PPD, bleeding on probing (BOP), and clinical probing attachment levels (CAL) measured using a stent, were recorded at baseline and at 1, 3, 6 and 9 months post-therapy. After subgingival scaling of all quadrants, 2 quadrants were randomly selected to be treated with metronidazole gel. RESULTS: A paired t-test on baseline values showed no bias between groups. Both treatments effectively reduced the signs of periodontitis. At each follow-up visit, reduction in PPD, CAL and BOP after the combined treatment was greater than for SRP alone. Paired t-tests showed that the improvement in the SRP+gel group was statistically significantly better (p<0.001) than for SRP alone (mean 0.5 +/- 0.6 mm. 95% CI 0.4-0.6 mm.) Similarly, the % of sites which improved to a final pocket depth of < or = 3 mm and the % of sites which improved over the 9 months of the study by as much as > or = 2 mm were greater for SRP+gel than for SRP alone. CONCLUSIONS: At the end of the study, the mean reductions for PPD were 1.0 mm (SRP) compared to 1.5 mm (SRP+gel), and for CAL they were 0.4 mm (SRP) compared to 0.8 mm (SRP+gel), with mean difference for CAL between treatments of 0.4 +/- 0.6 mm (95% confidence intervals of 0.3-0.6 mm). The combination therapy of SRP+gel was superior to the conventional treatment of SRP alone, and these differences were maintained for 9 months.

Adult↗
PubMed2000

Oral health status and access to care in a rural area of India.

A study was carried out in two villages in a rural area of Andhra Pradesh, India, 150 kilometres south of the state capital, Hyderabad. Ninety-eight women and sixty-two men, age range 15-70 years, were interviewed and examined. Information gathered included socio-economic data, distance travelled outside the village and previous access to health care. Data were recorded on periodontal status using CPITN and full periodontal charting. Comparisons were made between male and female subjects for travel outwith the village, attendance at medical and dental health facilities, tooth cleaning methods and materials and prevalence of periodontal disease. There was a high prevalence of chronic inflammatory periodontal disease in this population, and most of this was untreated. In view of the difficulties in access to health care, it would be prudent to offer good preventive oral health care within the rural community.

Adolescent↗
PubMed1999

Appraisal of a standardised periodontal referral proforma.

AIM: The primary objective was to assess the standard of new-patient referral communications to the Periodontology Department of a teaching hospital and evaluate any differences in referral quality between referrals that used a standardised proforma and conventional letters. Secondary objectives were to evaluate the potential influence on referral performance of age, postgraduate qualifications and country of qualification of the referring practitioners. DESIGN: A retrospective analysis of a randomised sample of all referral letters and proformae received during a nine-month period. SETTING: Letters and referral proformae received by the Periodontal Department of the teaching hospital between 1 January and 30 September 1995 were surveyed. METHODS: An objective Categorisation System for Periodontal Referral Quality (CSPRQ) was devised and tested for inter- and intra-examiner reproducibility. The referral communications in the random sample were then categorised for quality. The year, country of qualification (UK or non-UK) and possession or otherwise of postgraduate qualifications for each of the referring dentists was ascertained from the Dentists' Register. A Standard Normal Deviants (SND), or Z-test was applied to the resulting data. OUTCOME MEASURES: Acceptability or unacceptability of referral letters and proformae, related to the age (assessed by year of qualification), country of qualification and possession or otherwise of postgraduate qualifications. RESULTS: A random sample of 378 referral communications (from a total of 2663) was analysed. Sixty-three of the random sample were referral proformae. The use of the referral proforma was associated with a highly significantly better (P < 0.01) referral performance, than the use of referral letters. There was a trend for referrals from the small numbers of practitioners who were Fellows in Dental Surgery or Masters of Science to be better than those from other practitioners. There was also a trend for use of the referral proforma to enhance the referral performance of practitioners who had been qualified for more than 20 years. Use of the referral proforma highly significantly (P < 0.01) improved the quality of referrals from non-UK qualified practitioners. CONCLUSIONS: In this study, the quality of periodontal referrals was associated for the better with the use of a referral proforma.

Dental Clinics↗
PubMed1999

Retroviral transduction of human periodontal cells with a temperature-sensitive SV40 large T antigen.

The periodontal ligament (PDL) is considered to contain subpopulations of cells responsible for the development, repair and regeneration of the periodontium. Cell cultures have been used as model systems in order to understand the complex cellular and biochemical events underlying these processes. In order to obtain long-term cultures of these cells that can be cloned and characterized, primary cultures of PDL and gingival cells were infected with an amphotropic retroviral construct encoding a temperature-sensitive SV40 large T antigen (tsT). After selection for drug resistance, the cells expressed the T antigen and proliferated at 34 degrees C for more than 40 passages. However, when the T antigen was inactivated by incubation at 39 degrees C, the cultures became growth-arrested and the granularity of the cells increased, possibly as a result of differentiation. Reverse transcribed-polymerase chain reaction and flow cytometry showed that the tsT-transduced cells expressed a number of soft and hard connective-tissue antigens, including osteocalcin, osteonectin, osteopontin, collagen type I and alkaline phosphatase. Moreover, incubation of the transduced PDL cells at 39 degrees C was found to upregulate the expression of osteocalcin, osteopontin and collagen type I, but downregulate osteonectin. At this temperature, the presence of the dexamethasone downregulated type I collagen, while vitamin D3 had no effect on the expression of any of the antigens examined. Under all culture conditions, antigen expression was far higher in the transduced PDL cells than the gingival cells. The findings thus show that growth of the tsT-transduced PDL and gingival cells is temperature-dependent and that the presence of the T antigen increases their lifespan but does not ablate the expression of certain of their characteristic phenotypic and functional features.

Alkaline Phosphatase↗
PubMed1999

Perceptions of dentine hypersensitivity in a general practice population.

Recent studies have attempted to determine the prevalence of dentine hypersensitivity (DH) in both hospital and general practice. Results indicate that DH prevalence is higher in patients referred for specialist treatment than in general practice. The aim of this study was to determine perception and prevalence of DH in general practice. Completed questionnaires from 277 patients (115 males, 162 females, mean age 41.7 years [SD 14.36]) were collected. Self-reported DH prevalence (52%) was observed between the third and fourth decades, peaking in the third and in good agreement with that previously published (45.2%), and significantly more females complained of DH than males (SND=2.24, 95% CI 0.01734-0.2661). Cold was perceived as the most common cause of DH, in agreement with other studies. Only 12.6% of patients reported periodontal surgery compared to 15.5% previously. Of those who received hygiene therapy (67.9%) only 15.5% reported DH following treatment which mainly did not last >/=5 days. Most patients with DH did not perceive the condition as severe and did not seek treatment (75.1%). Only 23.3% used a desensitizing dentifrice. The results indicated that self-reporting of DH is lower than reported in a dental hospital population and was not perceived as a major dental problem by most patients in a general dental practice population.

Adult↗
PubMed1999

Localized adhesion molecule expression and circulating LFA-3 levels in adult and early onset forms of periodontitis.

Because of their importance in mediating cellular interactions in chronic inflammatory diseases, this study has examined the expression of a number of adhesion molecules in adult (n=11), generalized early onset (n=5) and localized early onset (n=2) forms of periodontitis. In comparison with immunostaining profiles of cryostat sections of healthy gingival tissue (n=7), the beta 1 integrins VLA-1, VLA-2 and VLA-4 were found to be up-regulated in periodontitis, with VLA-6 being markedly elevated. Although only small differences were observed in ICAM-1 and LFA-3 expression in the gingival epithelium, there was particularly notable up-regulation of these adhesion molecules within the inflammatory infiltrates of the diseased tissues. However, there were no statistically significant differences between the serum levels of a soluble form of LFA-3 in periodontitis patients (n=47) compared with healthy control subjects (n=40), although the generalized early onset and adult periodontitis groups exhibited wider ranges of circulating LFA-3. These findings show that there is localized modulation of adhesion molecule expression in the chronic inflammatory periodontal diseases studied, but that the levels of LFA-3 in the circulation nevertheless remain unaffected.

Adolescent↗
PubMed1999

Attrition, eruption, and the periodontium.

Features of natural masticatory function, of physiological attrition, both occlusal and approximal, and of continuing tooth eruption in adult life need to be borne in mind in considering how the chronic inflammatory periodontal diseases and dental caries have become so widespread. Evidence is reviewed showing that teeth continue to erupt in adulthood, that natural masticatory function prevented plaque accumulation at the approximal risk site of onset of both CIPDs and caries, that epithelial attachment to cementum may be physiological, and that periodontal attachment studies must be age-related.

Adult↗
PubMed1999

A 15-month evaluation of the effects of repeated subgingival minocycline in chronic adult periodontitis.

BACKGROUND: A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control. METHODS: One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15. RESULTS: Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated. CONCLUSIONS: Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.

Adult↗
PubMed1999

Effect of calcitonin on bone healing following titanium implant insertion.

The purpose of this study was to evaluate the effects of calcitonin administration on bone healing, following titanium implant insertion. Thirty adult New Zealand rabbits received one implant in each femur. Fifteen animals were randomized to provide test (calcitonin) and control (saline solution) groups. The animals were sacrificed 7, 14, 21, 28 and 42 days after the surgical procedure. The analyzed parameters were new endosteal/periosteal bone length, new endosteal/periosteal bone area and total cortical length. Considering treatment, histometric measurements showed significant differences (p < 0.05) favoring the control group considering periosteal bone length and periosteal bone area, the other parameters were statistically similar between control and test groups.

Analysis of Variance↗
PubMed1998

Psychosocial factors, dental plaque levels and smoking in periodontitis patients.

Psychological disturbances may lead patients to neglect oral hygiene. This study investigated whether a number of psychosocial factors (depression, state and trait anxiety, total and average perceived stress, and loneliness) could predict dental plaque levels in patients with adult onset rapidly progressive periodontitis (RPP) and routine chronic adult periodontitis (RCAP), before periodontal treatment. It was also examined whether RPP and RCAP patients differed on plaque and smoking. Plaque was scored in a sample of 6 teeth in each of 80 subjects, 40 with RPP, 40 with RCAP, before psychosocial questionnaire completion. Multiple regression was performed between plaque as the dependent and psychosocial factors, gender, education, form of periodontitis and smoking as independent variables. Only gender contributed significantly to prediction of plaque, t=-2.70, p=0.01, partial regression coefficient -0.37, 95% CI: -0.64 to -0.10, indicating that plaque was on average 0.37 lower for females than males, after adjusting for the other predictor variables. It was confirmed that RPP and RCAP patients did not differ significantly on plaque, univariate t-test(69.99)= 0.65, p=0.13. However, RPP patients smoked significantly more than RCAP patients t(69.72)=2.36, p=0.02. There was also a marginally significant correlation between depression and smoking, r=0.16, p=0.07. One possible reason advanced for the lack of an association between psychosocial factors and plaque, and the absence of a difference in plaque between RPP and RCAP patients is the fact that the patients involved in the present study were seen as secondary referrals. The gender difference in plaque levels and the greater incidence of smoking in RPP patients may be of significance in planning interventions with patients with periodontitis.

Adult↗
PubMed1998

Periodontal therapeutics--a viable option?

Research in recent years in periodontology has seen a shift from surgery towards medicine. While surgery, particularly regenerative, and including implants, continues to form an important element of periodontal treatment, the volume of treatment required and the results of recent and ongoing non-surgical studies clearly show that most future periodontics will be based on a physician-type approach. Improved diagnostics based on more precise periodontal disease classification, simplification of mechanical oral hygiene equipment and procedures, and the development of conventional and non-conventional chemical and physical adjuncts may be expected to reduce the rate of common periodontal disease advance, resulting in less complex treatments, and more of the latter coming to lie within the competence of the generalist and the hygienist working together. The rationale for non-surgical adjunctive therapy is extensive, far beyond the usual antimicrobial logic. It will also be important to control the oral microflora for systemic reasons, since increasingly strong links are being established between focal infection of oral origin, much of it periodontal, and a range of systemic diseases, including coronary heart disease, stroke, gastrointestinal disorders, and low birth weight, apart from severe, overt systemic infections. All these developments derive from a greatly improved understanding of the fundamentally ecological nature of the natural microbial biofilm that is dental plaque, and of its interactions with its human host.

Anti-Bacterial Agents↗
PubMed1998

The rationale for chemical adjuncts in plaque control.

The rationale for the adjunctive use of chemical anti-plaque agents depends on many factors in addition to the inherent antimicrobial properties of those agents. What is indicated generally is a basic oral hygiene regimen, as simple as it can be, bearing in mind the practical difficulties of getting people to clean their teeth optimally. Chemical adjuncts in many cases have the potential to simplify plaque control regimens. The mode of delivery may be critical to the success or otherwise of an adjunct. Adjuncts may simplify and accelerate the work of hygienists as well as patients. They may also serve to control plaque in severe forms of infectious inflammatory periodontal disease, as well as providing practical means of plaque control in the handicapped, or in those unable to practice optimal conventional home care oral hygiene. Chemical anti-plaque adjuncts offer a prospect of re-establishing the homeostasis of oral microbial biofilms fully consonant with the aims of modern periodontal medicine.

Anti-Bacterial Agents↗
PubMed1998

Influence of growth mode and sucrose on susceptibility of Streptococcus sanguis to amine fluorides and amine fluoride-inorganic fluoride combinations.

This study evaluated the susceptibility to amine fluorides (AmFs) of planktonic and biofilm cultures of Streptococcus sanguis grown with and without sucrose. Cultures were incubated with AmFs (250 mg of fluoride liter-1) for 1 min. The susceptibility of biofilms was less than that of the planktonic form and was further decreased by growth in the presence of sucrose.

Amines↗
PubMed1998

Ecological study of Streptococcus mutans, Streptococcus sobrinus and Lactobacillus spp. at sub-sites from approximal dental plaque from children.

Previous immunofluorescence (IF) studies have indicated that Streptococcus mutans may preferentially colonise specific sub-sites within approximal plaque. The present study aimed to extend these observations to other mutans streptococci and lactobacilli in such gingival margin plaque. Two hundred and seventy approximal plaque samples were taken from 90 teeth (3 from each tooth) in 64 children; three gingival margin sub-sites in relation to the contact area: away from (A), to the side of(S) and below (B) the contact area. Samples were processed by indirect IF using high-titred polyclonal anti-S. mutans 'c', anti-S. sobrinus 'd', anti-L. casei and anti-L. acidophilus antisera. An overall positive association was found between S. mutans 'c' and S. sobrinus 'd' (p < 0.001). Significant differences (p < 0.1) were found between the proportional counts at each sub-site for S. mutans 'c': A = 39%, S = 51% and B = 70%, and for S. sobrinus 'd' 21, 33 and 49%. Mutans streptococci (MS) appeared to preferentially colonise the sub-site below the contact area (B = 81%), compared with sub-sites A and S (48 and 62%, respectively). S. mutans 'c' and S. sobrinus 'd' were detected together at subsites A = 12%, S = 22%, and B = 38%, with proportional counts at B sites being higher than those at A (B > A, p < 0.01, and B > S, p < 0.05). Lactobacillus spp. were isolated rarely, and were usually found together with MS. There was a positive relationship between the presence of lactobacilli or MS and caries (white spot lesions only), although these species could frequently be isolated from noncarious sites. The presence of both S. mutans 'c' and S. sobrinus 'd' were strongly correlated with early caries lesions. In addition, this study confirmed the variation in the microflora at different sub-sites within approximal dental plaque.

Antibodies, Bacterial↗
PubMed1998

Flow cytometry analysis of gingival and periodontal ligament cells.

Gingival and periodontal ligament (PDL) fibroblasts are the major cellular components of periodontal soft connective tissues, but the precise differences between these cells are not yet known. In the present study, we have therefore examined the phenotypic and functional features of the cells obtained from gingival and PDL biopsy samples. Spindle-shaped cells characteristic of fibroblasts were the main cell type observed in vitro, although epithelial cells were also present in primary gingival cell cultures. Flow cytometry was used to measure the size and granularity of the cultured cells, and showed that the gingival fibroblasts were smaller and less granular compared with the PDL cells. The expression of certain key extracellular matrix (ECM) proteins, fibronectin, collagen type I, and tenascin was measured by flow cytometry. Analysis of the fluorescence profiles of these cultures showed that the majority of cells expressed fibronectin and that the average fluorescence intensity of this antigen in the PDL cells was higher than that in the gingival fibroblasts. Moreover, the fibronectin-positive PDL cells apparently comprised two subpopulations which expressed fibronectin at different levels, suggesting that the cells in the PDL cultures were functionally heterogeneous. The level of collagen type I was also found to be up-regulated in the PDL compared with the gingival cells and, as with fibronectin, was expressed at two different levels by subsets of the PDL cells. In contrast, tenascin was expressed at very similar levels by both the gingival fibroblasts and PDL cells. In addition, measurement of alkaline phosphatase, a marker enzyme for mineralized tissue-forming cells, showed that the PDL cells had higher activity than the gingival fibroblasts and that the alkaline phosphatase activity in the PDL cells was far more markedly up-regulated by dexamethasone. Our findings demonstrate that, despite their similar spindle-shaped appearance, fibroblasts derived from gingival and PDL tissues appear to display distinct functional activities which are likely to play a vital part in the maintenance of tissue integrity and regenerative processes.

Adolescent↗
PubMed1998

The microflora associated with human oral carcinomas.

Both local and systemic infections may complicate the morbidity of patients with oral malignant neoplasms, particularly those presenting intraorally. This study investigated the microbial contents of the biofilms present on the surfaces of oral squamous cell carcinomas. Biofilm samples were obtained from the central surface of the lesions in 21 patients (20 male, 1 female) aged 52.8 (+/- 8.2) years, and from contiguous healthy mucosa, before any antibiotic therapy or any tumour treatment. All lesions were keratinising squamous cell carcinomas with surface ulceration. Samples were transported in reduced brain heart infusion (BHI) broth and cultured within 1 h of removal, using aerobic and anaerobic complete and selective media. The median number of anaerobic colony forming units (CFU/ml) at the tumour sites (1.6 x 10(8)) was significantly higher than for the healthy (control) mucosa (3.0 x 10(7); P = 0.0001, Wilcoxon); the same was true for aerobes at the tumour sites (1.51 x 10(8)) relative to the controls (2.8 x 10(7); P = 0.0008, Wilcoxon). The species isolated in increased numbers at tumour sites were Veillonella, Fusobacterium, Prevotella, Porphyromonas, Actinomyces and Clostridium (anaerobes), and Haemophilus, Enterobacteriaceae and Streptococcus spp. (aerobes). Candida albicans was found at eight of the 21 tumour sites, but never at control sites. It was concluded that human oral carcinoma surface biofilms harbour significantly increased numbers of aerobes and anaerobes as compared with the healthy mucosal surface of the same patient. Candida albicans can also be present in these biofilms. These findings must be considered in relation to the known predisposition of such patients to systemic infections, and to the unpleasant complications of oral morbidity due to infected lesions.

Adult↗
PubMed1997

Variations in the predominant cultivable microflora of dental plaque at defined subsites on approximal tooth surfaces in children.

The distribution and composition of the resident microflora were determined in approximal gingival margin plaque from 21 premolars extracted from schoolchildren (mean age 12.0 +/- 1.8 yr). Indigo carmine (5% w v) was used to visualize plaque to facilitate sampling. About 1 mm2 of plaque was removed from sites away from (A), to the side of (S), and below (B) the contact area. Plaque samples were dispersed, serially diluted, and cultured on selective and non-selective agar media. An average of seven to nine species was found at each subsite. Streptococcus and Actinomyces were subdivided on the basis of a range of biochemical tests. The predominant Actinomyces and streptococcal species at most subsites were A. naeslundii and Strep. mitis biovar I. A. naeslundii and A. odontolyticus were isolated more often at subsite B (90.5 and 57.1%, respectively), and A. israelii at subsite S (66.7%) Strep. mitis 1 and Strep. sanguis were found more frequently at subsite S (76.2 and 66.7% respectively), whereas Strep mutans, Strep. sobrinus, Strep. gordonii and Veillonella spp. were recovered most commonly from subsite B (85.7, 33.3, 38.1 and 76.2%, respectively). The isolation frequencies of Strep. mutans and Strep. sobrinus were significantly higher at subsite B (A B p < 0.01 and p < 0.05, respectively). Veillonella spp. were significantly higher at subsites B and S (A < B, p > 0.01; B > S, p < 0.05), while Neisseria spp. were most common at subsite A (A > B. p > 0.03). IgAl protease-producing species were found at each subsite, but they formed only a small proportion of the total Streptococcus population. This study has shown that local variations were evident at different subsites, both with respect to species prevalence and to proportions of each species within each subsite. The population shifts in gingival margin plaque appear to relate to the location of plaque in relation to the most caries-prone site below the contact area B.

Analysis of Variance↗