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Biomedical subjects

Helen V Worthington

Publications and source records attributed to Helen V Worthington.

At least 19 recordsLinked to original sources
PubMed2006

Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review.

OBJECTIVE: To review systematically the evidence for an effect of long chain and shorter chain omega 3 fatty acids on total mortality, cardiovascular events, and cancer. DATA SOURCES: Electronic databases searched to February 2002; authors contacted and bibliographies of randomised controlled trials (RCTs) checked to locate studies. REVIEW METHODS: Review of RCTs of omega 3 intake for (3) 6 months in adults (with or without risk factors for cardiovascular disease) with data on a relevant outcome. Cohort studies that estimated omega 3 intake and related this to clinical outcome during at least 6 months were also included. Application of inclusion criteria, data extraction, and quality assessments were performed independently in duplicate. RESULTS: Of 15,159 titles and abstracts assessed, 48 RCTs (36,913 participants) and 41 cohort studies were analysed. The trial results were inconsistent. The pooled estimate showed no strong evidence of reduced risk of total mortality (relative risk 0.87, 95% confidence interval 0.73 to 1.03) or combined cardiovascular events (0.95, 0.82 to 1.12) in participants taking additional omega 3 fats. The few studies at low risk of bias were more consistent, but they showed no effect of omega 3 on total mortality (0.98, 0.70 to 1.36) or cardiovascular events (1.09, 0.87 to 1.37). When data from the subgroup of studies of long chain omega 3 fats were analysed separately, total mortality (0.86, 0.70 to 1.04; 138 events) and cardiovascular events (0.93, 0.79 to 1.11) were not clearly reduced. Neither RCTs nor cohort studies suggested increased risk of cancer with a higher intake of omega 3 (trials: 1.07, 0.88 to 1.30; cohort studies: 1.02, 0.87 to 1.19), but clinically important harm could not be excluded. CONCLUSION: Long chain and shorter chain omega 3 fats do not have a clear effect on total mortality, combined cardiovascular events, or cancer.

Cardiovascular Diseases↗
PubMed2006

Outcome of implant therapy in patients with previous tooth loss due to periodontitis.

BACKGROUND: It is frequently debated whether implant treatment in individuals with previous tooth loss due to periodontitis is characterized by an increased incidence of implant loss and peri-implantitis. OBJECTIVE: The objective of the present systematic review was to assess whether individuals with previous tooth loss due to periodontitis have an increased risk of loss of suprastructures, loss of implants, peri-implantitis, and peri-implant marginal bone loss as compared with individuals with previous tooth loss due to reasons other than periodontitis. SEARCH STRATEGY: Studies considered for inclusion were searched in MEDLINE (PubMed) and relevant journals were hand searched. Moreover, reference lists of articles selected for full-text screening as well as previously published reviews relevant for the present systematic review were searched. The search was performed by one reviewer and was restricted to human studies published from January 1, 1980 to January 1, 2006. No language restrictions were applied. SELECTION CRITERIA: Prospective and retrospective cohort studies with at least a 5-year follow-up comparing the outcome of implant treatment in individuals with periodontitis-associated and non-periodontitis-associated tooth loss, respectively, were included. The outcome measures were survival of suprastructures, survival of implants, occurrence of peri-implantitis, and peri-implant marginal bone loss. The 5- and 10-year time points were evaluated. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, methodological quality assessment, and data extraction were conducted in duplicate and independently by two of the authors. The authors were contacted for missing information. Results were expressed as random effect models using weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes with 95% confidence intervals (CIs). MAIN RESULTS: Two studies with a 5- and 10-year follow-up, respectively, were identified including a total of 33 patients with tooth loss due to periodontitis and 70 patients with non-periodontitis-associated tooth loss. There was no significant difference in the survival of the suprastructures after 5 years. Furthermore, there were no significant differences in the survival of the implants after 5 and 10 years. However, there were significantly more patients affected by peri-implantitis in the group with periodontitis-associated tooth loss during the 10-year follow-up period, risk ratio (RR) 9 (95% CI 3.94-20.57). Moreover, significantly increased peri-implant marginal bone loss was observed in patients with periodontitis-associated tooth loss after 5 years, mean difference 0.5 mm (95% CI 0.06-0.94). CONCLUSIONS: The survival of the suprastructures and the implants was not significantly different in individuals with periodontitis-associated and non-periodontitis-associated tooth loss. However, significantly increased incidence of peri-implantitis and significantly increased peri-implant marginal bone loss were revealed in individuals with periodontitis-associated tooth loss. The small sample size and the methodological quality assessment of the two studies suggest that the results should be interpreted with caution. Consequently, further long-term studies focusing particularly on the outcome of implant treatment in young adults with aggressive periodontitis are needed before final conclusions can be drawn about the outcome of implant treatment in patients with a history of periodontitis.

Alveolar Bone Loss↗
PubMed2006

Orthodontic retention: a systematic review.

OBJECTIVE: To evaluate the effectiveness of different retention strategies used to maintain tooth position after treatment by orthodontic appliances. DATA SOURCES: The search strategy was carried out according to the standard Cochrane systematic review methodology. The following databases were searched for randomized clinical trials (RCT) or controlled clinical trials (CCT): Cochrane Oral Health Group Trials Register, Cochrane Clinical Trials Register, MEDLINE and EMBASE. No language restrictions were applied. Authors of trials were contacted to identify unpublished trials. Inclusion and exclusion criteria were applied when considering the studies to be included and a quality assessment made for each paper. DATA SELECTION: The primary outcome was the amount of relapse. Secondary outcomes were survival of retainers, adverse effects on oral health and patient satisfaction. DATA EXTRACTION: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two reviewers. Five studies (2 RCTs and 3 CCTs) fulfilled the inclusion criteria. DATA SYNTHESIS: There was evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (P<0.001) and maxillary anterior segments (P<0.001) when the CSF (circumferential supracrestal fiberotomy) was used in conjunction with a Hawley retainer, compared with a Hawley retainer alone. However, this evidence may be unreliable due to flaws in the study design. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. CONCLUSIONS: There is currently insufficient evidence on which to base the clinical practice of orthodontic retention.

Humans↗
PubMed2006

Comparison of interdental cleaning methods: a randomized controlled trial.

BACKGROUND: Although interdental cleaning is an integral component of home plaque control for periodontally involved patients, limited data exist on the periodontal benefits of commonly used interdental cleaning methods before definitive root surface debridement is undertaken. Therefore, the aim of this study was to compare the effects of a customized interdental brushing technique and a customized flossing technique on clinical periodontal outcomes prior to root surface debridement in chronic periodontitis cases. METHODS: This was a single-blind, randomized controlled clinical trial. Seventy-seven patients with chronic periodontitis were measured for plaque, relative interdental papillae level, Eastman interdental bleeding index, probing depths, and bleeding on probing at interdental sites and underwent a 10-minute hand scaling to remove easily accessible calculus deposits. Before group allocation, patients were advised on toothbrushing and instructed in two customized methods of interdental cleaning involving dental floss and precurved interdental brushes. Materials were supplied after random allocation. Participants were recalled at 6 and 12 weeks for clinical measurements, reinforcement of instructions, and fresh materials. RESULTS: There were significant reductions from baseline for all indices in both groups (P <0.01). At 6 weeks, the interdental brush group improved more than the floss group in every parameter (P <0.05). By 12 weeks, the changes in plaque, papillae level, and probing depths were significantly greater in the interdental brush group than the floss group (P <0.01). CONCLUSION: This trial demonstrated that patients were able to improve clinical periodontal outcomes by interdental cleaning, particularly with interdental brushes, even before thorough root surface debridement was undertaken.

Adult↗
PubMed2005

The role of implant surface modifications, shape and material on the success of osseointegrated dental implants. A Cochrane systematic review.

We tested the hypothesis of no difference in implant failures between various dental implant types. We searched for all randomised clinical trials comparing different implant types/systems with a follow up of at least one year on four databases. Screening of eligible trials, quality assessment and data extraction were conducted in duplicate. Thirty-one trials were identified. Twelve trials, reporting results of 512 patients, were included. No significant differences were observed for implant failures. There were minor statistically significant differences for peri-implant bone level changes. Turned surfaces had a 20% reduction in risk of being affected by perimplantitis over a 3-year period.

Dental Implantation, Endosseous↗
PubMed2005

'Occlusal sketch'; a reliable technique for technicians to check that the occlusion of models is correct?

The aim of this study was to determine whether the occlusal sketch technique can be used as a reliable means of verifying the occlusal contacts on articulated casts. Occlusal markings were made on 30 sets of upper and lower dentate casts and these were recorded using the 'occlusal sketch' technique. Fifteen out of the total 30 pairs of casts were deliberately corrupted by the clinician so that they no longer matched the record on the 'occlusal sketch'. Three dental technicians were asked to judge in which of the 30 casts the occlusal contacts differed from those represented by the occlusal sketch. The results showed almost perfect agreement between the technicians in correctly identifying which casts had marked occlusal contacts which differed from those recorded on the occlusal sketch. The occlusal sketch provides a reliable way of communicating occlusal contacts that occur in a case, between clinician and technician.

Communication↗
PubMed2004

Dietary antioxidant lack, impaired hepatic glutathione reserve, and cholesterol gallstones.

BACKGROUND: Theoretical considerations and experimental studies suggest a causal connection between micronutrient antioxidant insufficiency and the development of human gallstones. METHODS: Fasting plasma/serum samples from 24 patients with cholesterol gallstones-on unchanged lifestyles-were analysed for the four main micronutrient antioxidants, glutathione and factors that impact or report upon glutathione homeostasis. The results were assessed by comparison with laboratory referent ranges. RESULTS: The vitamin E:cholesterol ratio was lower in patients than controls (P=0.021) as also concentrations of beta-carotene (P=0.001) and vitamin C (P=0.001) but not selenium (P=0.280). A fall in plasma glutathione (P=0.001) was also accompanied by lower values of pyridoxyl-5-phosphate (the coenzyme that participates in vitamin B6-dependent enzyme reactions) which is involved in glutathione biosynthesis (P<0.001), and of folate (P=0.012) but not vitamin B12 (P=0.377) that participate in its regeneration via the methionine-homocysteine pathway. Despite these defects, values for plasma homocysteine were not significantly different from controls (P=0.092)-an anomaly rationalised by poor levels of precursor methionine (P=0.003) and cysteine (P=0.046). CONCLUSIONS: Micronutrient antioxidant-including sulphur amino acid-lack, with disturbed glutathione homeostasis, are features of cholesterol gallstone disease.

Adult↗
PubMed2004

Enamel matrix derivative for periodontal tissue regeneration in treatment of intrabony defects: a Cochrane systematic review.

We reviewed the literature on the efficacy of enamel matrix derivative (EMD) in comparison with open flap debridement, guided tissue regeneration (GTR), and bone grafting for the treatment of intrabony defects. We searched four major electronic databases for randomized controlled trials (RCTs) with at least one year of follow-up. Several journals were handsearched with no language restrictions. Outcome measures were: tooth loss, changes in probing attachment levels (PAL), pocket depths (PPD), gingival recessions (REC), marginal bone levels on intraoral radiographs, and postoperative infections. Screening of eligible RCTs, assessment of the methodological quality, and data extraction were conducted in duplicate. No difference in tooth loss was observed. A meta-analysis (eight trials) showed that EMD-treated sites displayed statistically significant PAL improvements (mean difference 1.3 mm) and PPD reduction (1 mm) when compared to flap surgery. When EMD was compared to GTR (six trials), GTR showed a statistically significant reduction of PPD (0.6 mm) and increase of REC (0.5 mm). No difference in postoperative infections was observed. No trials compared EMD with bone grafts alone. EMD is able to significantly improve PAL levels and PPD reduction when compared to flap surgery; however, there is no evidence that more teeth could be saved. There was no evidence of important differences between EMD and GTR.

Alveolar Bone Loss↗
PubMed2003

Comparing different methods to detect and correct nonresponse bias in postal questionnaire studies.

OBJECTIVES: This study compares methods for detecting and correcting the bias associated with nonresponse to postal questionnaires. METHODS: Questionnaires were sent out in three sequential stages to parents of all 5-year-old children examined in a clinical survey. Each stage progressively targeted nonresponders. Data on dmft and area measures of socioeconomic status were available for all children. Estimates for whole population dmft were produced by different methodologies comparing the relationship between dmft and stage of response and three area measures of socioeconomic status. RESULTS: A total of 1,776 children were examined and 1,437 questionnaires were obtained, a response rate of 80.9 percent. The mean dmft of the total population (1.49) was 17.3 percent more than responders (1.27). The dmft of the nonresponders was 2.41, 89.7 percent more than responders. There were significant linear trends in dmft and socioeconomic status across the mailing stages. The methodology using mailing stage regressed against dmft produced the most accurate adjusted dmft value (1.42). The methods using area measures of socioeconomic status produced nearly identical adjusted dmft values ranging from 1.31 to 1.32. CONCLUSIONS: Even with an "acceptable" response rate, nonresponse bias can still be present. Researchers should report the outcomes of analyses to detect nonresponse bias when publishing questionnaire studies.

Bias↗
PubMed2003

Therapeutic use of hyperbaric oxygen for irradiated dental implant patients: a systematic review.

The aim of this systematic review was to investigate the effectiveness of hyperbaric oxygen (HBO) therapy for irradiated patients who require dental implants using data from randomized controlled clinical trials (RCTs). The review was prepared according to Cochrane Collaboration guidelines. The Cochrane Oral Health Group Specialist Register and the Cochrane Controlled Trials Register were searched (Cochrane Library 2002, Issue 2), together with Medline from 1966 or Embase from 1974. Several journals were hand-searched, and fifty-five implant manufacturers were contacted in an attempt to identify ongoing or unpublished studies. The results were that no RCTs comparing HBO with no HBO for implant treatment in irradiated patients were identified. Our principal conclusions are that clinicians ought to be aware and make patients aware of the lack of reliable clinical evidence for or against the clinical effectiveness of HBO therapy in irradiated patients requiring dental implants. There is a need for RCTs to determine the effectiveness of HBO.

Cranial Irradiation↗
PubMed2002

Orofacial pain: just another chronic pain? Results from a population-based survey.

Features of somatisation have been shown to predict the onset of widespread body pain. This study aims to determine to what extent persons with orofacial pain syndromes share these features and to what extent they are uniquely related to oral mechanical factors. We have conducted a population-based cross-sectional survey in the South-East Cheshire area of the United Kingdom involving 2504 individuals aged 18-65 years. All participants completed a postal questionnaire which enquired about the occurrence of both orofacial pain and widespread body pain. It also enquired about potential risk factors for one or both conditions. In total, 473 subjects (23%) reported orofacial pain only, 123 (6%) widespread pain only, while 85 (4%) reported both. The number reporting both was significantly higher than would be expected if the symptoms were independent (P<0.001). Several oral mechanical factors were significantly associated with both orofacial pain and widespread body pain (grinding teeth, clicking jaw, missing teeth), while two (facial trauma, locking jaw) were specifically related to orofacial pain. Both pain syndromes were associated equally with high levels of psychological distress, indicators of somatisation and maladaptive response to illness. These results suggest that orofacial pain syndromes may commonly be a manifestation of the process of somatisation and the excess reporting of some local mechanical factors amongst persons with these symptoms, may not be uniquely associated with pain in the orofacial region.

Adult↗
PubMed2002

The association between psychological factors and oro-facial pain: a community-based study.

OBJECTIVE: To examine the hypothesis that psychological factors of psychological distress, maladaptive response to illness and perception of happiness in childhood, are associated with self-reported oro-facial pain (OFP). METHOD: A cross-sectional population-based study was conducted in South-East Cheshire, UK. The adjusted participation rate was 74%, and 2504 adults aged 18-65 years participated in the study. RESULTS: A report of not having had a happy childhood was associated with risk of 1.6 (95% CI 1.4-2.0) of reporting OFP. An increased propensity to report symptoms associated with OFP was seen for those individuals with higher levels of psychological distress measured using the general health questionnaire (GHQ) with the risk of 2.7 (95% CI 2.3-3.2) in the highest category. All components of the illness behaviour questionnaire (IBQ) were associated with presence of OFP. There was a linear increase in risk (test for trend, P<0.01) associated with the report of OFP for general hypochondriasis, disease conviction, affective inhibition, affective disturbance, and irritability. However there was a significant decrease in risk with a high score for perception of illness (0.6; 95% CI 0.6-0.7) and denial (0.6; 95% CI 0.5-0.7). None of the factors showed significant change in estimates when adjusted for age and gender. CONCLUSIONS: This large cross-sectional community-based study showed significant association for all of the factors considered. The obtained data raise interesting questions of cause and effect for which further, longitudinal studies are required to establish temporal relationship between these factors and the onset, cause, and treatment of OFP.

Adolescent↗
PubMed2002

The effects of an immediately pre-surgical chlorhexidine oral rinse on the bacterial contaminants of bone debris collected during dental implant surgery.

Dental implant surgery produces bone debris that can be used in the "simultaneous augmentation" technique. Although this debris is contaminated with oral bacteria, a stringent aspiration protocol has been shown to reduce the levels of contamination. Chlorhexidine mouthrinse is a well-proven antibacterial rinse that has been shown to reduce infectious complications associated with dental implants. This study examined the effect of pre-operative rinsing with a 0.1% chlorhexidine digluconate mouthrinse on the bacterial contaminants present in collected bone debris bone (CBD). Twenty partially edentate patients were randomly allocated into equal groups and underwent bone collection using the Frios Bone Collector (FBC) during the insertion of two dental implants. In group T a pre-operative chlorhexidine rinse was used, whilst in group C sterile water was used. For both groups, a stringent bone collection protocol was used. Bone samples were immediately transported for microbial analysis. Colonial and microscopic morphology, gaseous requirements and identification kits were utilised for identification of the isolated microbes. Thirty-nine species were identified including a number associated with disease, in particular Actinomyces odontolyticus, Clostridium bifermentans, Prevotella intermedia, and Propionibacterium propionicum. Samples from group T (chlorhexidine mouthrinse) yielded significantly fewer organisms (P < 0.001) than in group C (sterile water mouthrinse). Gram-positive cocci dominated the isolates from both groups. It is concluded that if bone debris is to be used for the purpose of immediate simultaneous augmentation, a preoperative chlorhexidine mouthrinse should be utilised in conjunction with a stringent aspiration protocol to reduce further the bacterial contamination of CBD.

Actinomyces↗
PubMed2002

Oro-facial pain in the community: prevalence and associated impact.

STUDY OBJECTIVE: To determine the prevalence of oro-facial pain (OFP) in the population and within-population subgroups and to describe the associated disability. DESIGN: Cross-sectional population study. SETTING: General medical practice in South East Cheshire, United Kingdom. PARTICIPANTS: A random sample of 4000 adults aged 18-65 years of whom 2504 responded (adjusted participation rate 74%). MAIN RESULTS: The overall prevalence of OFP was 26% (95% Confidence Interval (CI) 24%, 28%). The prevalence of symptoms was higher in women (30%) than in men (21%) and in both sexes the highest (30%) prevalence was found in the 18-25 year age group and the lowest (22%) in the 56-65 age group. Of all the participants, 12% had pain in or around the eyes, 10% reported pain in and around the temples, 6% pain in front of the ears and 6% pain in the jaw joints. Only 46% of the participants with OFP had sought professional advice from a dentist or general medical practitioner and 17% had to take time off work or were unable to carry out normal activities because of pain. CONCLUSIONS: OFP is a common symptom experienced by a quarter of the adult population, of whom only 46% seek treatment. The prevalence is higher in women and younger age groups.

Absenteeism↗
PubMed2002

Meta-analyses involving cross-over trials: methodological issues.

BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials. METHODS: The characteristics of these trials are outlined, with detailed examples of methods for analysis for both continuous and binary data. These case studies are then extended into the context of a meta-analysis. The Cochrane Library was surveyed to assess current practice for synthesis. RESULTS: Methods are described for continuous and binary data for use both when the necessary paired data are given and also when they need to be calculated or imputed, and some suggestions are provided to help people wishing to synthesize data from cross-over trials into meta-analyses. The survey suggested that about 8% of the trials in the Cochrane library were cross-over trials and 18% of the reviews referred to such trials, although there was no consistent approach to their inclusion into the reviews. CONCLUSIONS: Methods do exist for including valuable information from two-period, two-treatment cross-over trials into quantitative reviews. However, poor reporting of cross-over trials will often impede attempts to perform a meta-analysis using the available methods.

Cross-Over Studies↗
PubMed2002

Urinary fluoride excretion of young children exposed to different fluoride regimes.

AIMS: To compare 24-hour urinary fluoride excretion in young children exposed to different fluoride regimes. DESIGN: Twenty-four-hour urine samples were collected from children aged between 1.8 and 5.2 years. Samples were collected from Cork, Ireland (n=19) where the water is fluoridated to a concentration between 0.8 and 1.0 mg/l; Knowsley, UK, where the water fluoride concentration is <0.1 mg/l (n=22); and from children in Knowsley drinking milk containing 0.5 mg fluoride in nursery school each day (n=16). The volume of the samples was measured, they were analysed for fluoride concentration and the 24-hour urinary fluoride excretion was calculated. RESULTS: It was found that the mean fluoride excretion in response to usual conditions of fluoride intake in these children was 0.21 mg (SD=0.14) in non-fluoridated Knowsley; 0.36 mg (SD=0.11) in fluoridated Cork and 0.30 mg (SD=0.10) in the children drinking fluoridated school milk. CONCLUSIONS: The daily fluoride excretion in these children, corrected for age and fluoride ingested from toothpaste, appeared to indicate that the fluoride intake in the children drinking fluoridated school milk was somewhere between those living in an optimally fluoridated area and those in a low fluoride area.

Animals↗
PubMedDate not supplied

The reporting of randomized controlled trials in prosthodontics.

PURPOSE: This article evaluates the reporting of randomized controlled trials (RCT) in prosthodontics, excluding endosseous implant-based prosthetics. MATERIALS AND METHODS: Reports of RCTs published to the end of 2000 in any language were identified using a multilayered search strategy. The Cochrane Oral Health Group specialized register, Medline, and personal libraries were searched. Three researchers appraised the articles independently using guidelines following Jadad and CONSORT, complemented with an evaluation of the appropriateness of the reported statistics. RESULTS: Ninety-two reports of RCTs were evaluated, covering a wide spectrum of study hypotheses, topics, and issues within various prosthodontic domains. The interrater agreements on appraisal criteria were relatively high, with median kappa values ranging between 0.65 and 0.79. The reports were in general of poor methodologic quality. Randomization and procedures for concealment allocation were not described in 70% of the articles. The methods used to generate the random allocation sequence were not mentioned in 82%. The methods used to implement the random allocation sequence, clarifying whether it was concealed until all interventions were assigned, was not mentioned in 94%. Reporting who generated allocation sequence, who enrolled patients, and who assigned participants to groups was not reported in 7%. Reasons for withdrawals were not given in 23% of the reports. No attempt at blinding was reported in 72%. Statistical analysis was not described in 6% of the papers, while these analyses were assessed as appropriate for 75%, unclear in 12%, and inappropriate in 7%. CONCLUSION: Few RCTs in prosthodontics are reported in accordance with contemporary guidelines for adequate reporting of trials.

Adhesives↗