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Biomedical subjects

R M Palmer

Publications and source records attributed to R M Palmer.

At least 19 recordsLinked to original sources
PubMed2001

Development and validation of a prognostic index for 1-year mortality in older adults after hospitalization.

CONTEXT: For many elderly patients, an acute medical illness requiring hospitalization is followed by a progressive decline, resulting in high rates of mortality in this population during the year following discharge. However, few prognostic indices have focused on predicting posthospital mortality in older adults. OBJECTIVE: To develop and validate a prognostic index for 1 year mortality of older adults after hospital discharge using information readily available at discharge. DESIGN: Data analyses derived from 2 prospective studies with 1-year of follow-up, conducted in 1993 through 1997. SETTING AND PATIENTS: We developed the prognostic index in 1495 patients aged at least 70 years who were discharged from a general medical service at a tertiary care hospital (mean age, 81 years; 67% female) and validated it in 1427 patients discharged from a separate community teaching hospital (mean age, 79 years; 61% female). MAIN OUTCOME MEASURE: Prediction of 1-year mortality using risk factors such as demographic characteristics, activities of daily living (ADL) dependency, comorbid conditions, length of hospital stay, and laboratory measurements. RESULTS: In the derivation cohort, 6 independent risk factors for mortality were identified and weighted using logistic regression: male sex (1 point); number of dependent ADLs at discharge (1-4 ADLs, 2 points; all 5 ADLs, 5 points); congestive heart failure (2 points); cancer (solitary, 3 points; metastatic, 8 points); creatinine level higher than 3.0 mg/dL (265 micromol/L) (2 points); and low albumin level (3.0-3.4 g/dL, 1 point; <3.0 g/dL, 2 points). Several variables associated with 1-year mortality in bivariable analyses, such as age and dementia, were not independently associated with mortality after adjustment for functional status. We calculated risk scores for patients by adding the points of each independent risk factor present. In the derivation cohort, 1-year mortality was 13% in the lowest-risk group (0-1 point), 20% in the group with 2 or 3 points, 37% in the group with 4 to 6 points, and 68% in the highest-risk group (>6 points). In the validation cohort, 1-year mortality was 4% in the lowest-risk group, 19% in the group with 2 or 3 points, 34% in the group with 4 to 6 points, and 64% in the highest-risk group. The area under the receiver operating characteristic curve for the point system was 0.75 in the derivation cohort and 0.79 in the validation cohort. CONCLUSIONS: Our prognostic index, which used 6 risk factors known at discharge and a simple additive point system to stratify medical patients 70 years or older according to 1-year mortality after hospitalization, had good discrimination and calibration and generalized well in an independent sample of patients at a different site. These characteristics suggest that our index may be useful for clinical care and risk adjustment.

Aged↗
PubMed2001

The relationship of sedation to deliberate self-extubation.

STUDY OBJECTIVES: To evaluate the relationship between sedative therapy and self-extubation in a large medical-surgical intensive care unit (ICU). DESIGN: Retrospective, case-controlled study. SETTING: Large teaching hospital. PATIENTS: All adult patients who underwent unplanned self-extubation during a 12-month period (n = 50). Each patient was matched to two control patients who did not self-extubate based on age, gender, dates in hospital and diagnosis. INTERVENTIONS: none. MEASUREMENTS: Data collected included time to self extubation, dosages and types of benzodiazepines, opioid analgesics, antipsychotics, and hypnotics. Data on the degree of agitation as assessed by nursing staff also were obtained. MAIN RESULTS: When compared to controls, patients in the self-extubation group were more likely to have received benzodiazepines (59% vs. 35%; p < 0.05), but equally likely to have received opioids and/or paralytic drugs. Patients who self-extubated were twice as likely as controls to be agitated (54% vs. 22%; p < 0.05). Use of benzodiazepines was more common in agitated patients than in nonagitated patients (62% vs. 35%; p < 0.02). Among nonagitated patients who self-extubated, increased use of benzodiazepines (57% vs. 29%; p < 0.05) was noted when compared to nonagitated controls. CONCLUSIONS: In intubated ICU patients, benzodiazepines may not consistently treat agitation effectively or prevent self-extubation. Such an effect may be due to paradoxical excitation, disorientation during long-term administration, or differences in drug administration between ICU and operating room (OR) environments.

Aged↗
PubMed2001

Outcomes following physical restraint reduction programs in two acute care hospitals.

BACKGROUND: Physical restraint rates can be reduced safely in long term care settings, but the strategies used to prevent wandering, falls, and patient aggression have not been tested for their effectiveness in preventing therapy disruption. A restraint reduction program (RRP) consisting of four core components (administrative, educational, consultative, and feedback) was implemented in 1998-1999 in 14 units at two acute care hospitals in geographically distant cities. METHODS: The RRP was targeted at units with prevalence rates of > or = 4% for non-intensive care units (non-ICUs) and > or = 25% for ICUs, as well as two additional units. The RRP was implemented by an interdisciplinary team consisting of geriatricians and nurse specialists. RESULTS: Of the 16,605 admissions to the RRP units, 2,772 cases received RRP consultations. Only six units (four of seven general units and two of six ICUs) demonstrated a relative reduction of > or = 20% in the physical restraint use rate. No increase in secondary outcomes of patient falls and therapy disruptions (patient-initiated discontinuation or dislodgment of therapeutic devices) occurred, injury rates were low, and no deaths occurred as a direct result of either a fall or therapy disruption event. DISCUSSION: Given the minimal success in the ICU settings, further studies are needed to determine effective nonrestraint strategies for critical care patients. ICU clinicians need to be persuaded of the favorable risk-to-benefit ratio of alternatives to physical restraint before they will change their practice patterns. SUMMARY: Efforts to identify more effective interventions that match patient needs and to identify non-clinician factors that affect physical restraint use are needed.

Academic Medical Centers↗
PubMed2001

Validation of smoking status in clinical research into inflammatory periodontal disease.

BACKGROUND: Tobacco smoking is an accepted risk factor for periodontal disease. Most studies in the periodontal literature rely on reported smoking habits which can be unreliable. This review specifically addresses this problem. METHODS: Methods of assessing tobacco smoke exposure, variation in individual smoking habits, classification of former/ex-smokers, and validation of abstinence in smoking cessation studies receive attention. DISCUSSION: Additionally, clinical studies that have examined periodontal health in subjects with validated smoking status are discussed.

Bias↗
PubMed2001

Comparison of the validity of periodontal probing measurements in smokers and non-smokers.

AIM: To determine whether the reduced inflammation and bleeding and increased fibrosis reported in tobacco smokers affect the validity of clinical probing measurements by altering probe tip penetration. METHOD: A constant force probe was used to measure probing depths and sound bone levels at six sites on 64 molar teeth (384 sites) in 20 smoking and 20 non-smoking patients from grooves made with a bur at the gingival margin prior to extraction. Connective tissue attachment levels were measured from the grooves with a dissecting microscope following extraction. Data were analysed using robust regression with sites clustered within subjects. RESULTS: Sites in smokers showed more calculus but less bleeding than sites in non-smokers (p<0.05). The mean clinical probing depth was not significantly different (smokers: 5.54 mm, confidence intervals=4.81 to 6.28; non-smokers: 6.05 mm, ci=5.38 to 6.72). The corresponding post-extraction pocket depth measurements (smokers: 4.95 mm, ci=4.30 to 5.61; non-smokers: 5.23 mm, ci=4.49 to 5.96) were less than clinical probing depth in sites from both smokers and non-smokers (p<0.01). However, the proportional difference was less in smokers (p<0.05), particularly in deeper pockets, indicating that clinical probe tip penetration of tissue was greater in non-smokers. Regression analysis indicated that the presence of calculus and bleeding also influenced the difference in clinical probe penetration (p<0.05). CONCLUSION: Clinical probing depth at molar sites exaggerates pocket depth, but the probe tip may be closer to the actual attachment level in smokers due to less penetration of tissue. This may be partly explained by the reduced inflammation and width of supra-bony connective tissue in smokers. These findings have clinical relevance to the successful management of periodontal patients who smoke.

Adult↗
PubMed2001

Dose-years as an improved index of cumulative tobacco smoke exposure.

In assessing the link between tobacco smoking and disease, it is important to determine longterm, cumulative exposure to tobacco smoke as accurately as possible. Conventional methods of assessing exposure to tobacco smoke each have intrinsic limitations. Self-reporting of tobacco use, and the conversion of this data to pack-years, can be prone to error due to individuals wishing to conceal smoking habits, inaccurate reporting of daily cigarette consumptions or years of smoking, and failure to take into account the variation that exists in inter-individual smoking experiences. Measurement of cotinine, a major metabolite of nicotine in humans, is a reliable method of monitoring recent doses of tobacco smoke exposure. Cotinine concentrations, however, may remain stable in smokers over the longer term. Therefore, dose-years, and more specifically cotinine-years, may represent an improved index of cumulative tobacco smoke exposure.

Biomarkers↗
PubMed2001

Elevated systemic concentrations of soluble ICAM-1 (sICAM) are not reflected in the gingival crevicular fluid of smokers with periodontitis.

Raised serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in smokers could have immunomodulatory effects in periodontitis. The aim of this study was to compare serum and gingival crevicular fluid (GCF) concentrations of sICAM-1 in smokers and non-smokers with periodontal disease. sICAM-1 in serum and GCF collected from age- and gender-matched smokers (n = 14) and non-smokers (n = 14) with periodontitis were measured by ELISA. Mean serum sICAM-1 concentrations were significantly elevated in smokers (331 ng mL(-1)), compared with non-smokers (238 ng mL(-1), p = 0.008). However, the concentration of sICAM-1 in the GCF was significantly lower in the smokers (83 ng mL(-1)), compared with non-smokers (212 ng mL(-1), p = 0.013). The difference between concentrations of sICAM-1 in GCF and serum was significant only in smokers (p < 0.001). Since GCF is a serum-derived tissue exudate, these results suggest that, in smokers, circulating sICAM-1 molecules are affected either in their passage from the periodontal microvasculature or within the periodontal tissues.

Adult↗
PubMed2000

Dramatic decline in circulating intercellular adhesion molecule-1 concentration on quitting tobacco smoking.

The concentration of soluble ICAM-1 (sICAM-1) is significantly elevated in smokers, but it is unclear if smoking is the direct cause of elevated sICAM-1 levels, if the relationship between smoking and sICAM-1 level is dose-dependent, and if smoking cessation may lead to a decline in sICAM-1. We sought to clarify the relationship between smoking and sICAM-1 in a group of smokers who quit smoking for 1 year (n = 30) and a control group who continued to smoke (n = 30). A dose-dependent relationship between plasma sICAM-1 concentration and daily cigarette consumption (P = 0.02), plasma cotinine level (P = 0.02), and expired CO level (P = 0.007) was observed at baseline (n = 60). The mean change in sICAM-1 concentration after 52 weeks was greater for quitters than for continuing smokers (mean difference = -71.1 ng/ml, P < 0.001). The influence of smoking on sICAM-1 needs to be carefully considered in clinical trials. Soluble ICAM-1 remains bioactive and may contribute to pathogenic processes; therefore, reduction in the concentration of circulating ICAM-1 molecules may directly contribute to the health benefits associated with smoking cessation.

Adult↗
PubMed2000

RNA turnover and protein synthesis in fish cells.

Protein synthesis in fish has been previously correlated with RNA content. The present study investigates whether protein and RNA synthesis rates are similarly related. Protein and RNA synthesis rates were determined from 3H-phenylalanine and 3H-uridine incorporation, respectively, and expressed as % x day(-1) and half-lives, respectively. Three fibroblast cell lines were used: BF-2, RTP, CHSE 214, which are derived from the bluegill, rainbow trout and Chinook salmon, respectively. These cells contained similar RNA concentrations (approximately 175 microg RNA x mg(-1) cell protein). Therefore differences in protein synthesis rates, BF-2 (31.3 +/- 1.8)>RTP (25.1 +/- 1.7)>CHSE 214 (17.6 +/-1.1), were attributable to RNA translational efficiency. The most translationally efficient RNA (BF-2 cells), 1.8 mg protein synthesised x microg(-1) RNA x day(-1), corresponded to the lowest RNA half-life, 75.4 +/- 6.4 h. Translationally efficient RNA was also energetically efficient with BF-2 cells exploiting the least costly route of nucleotide supply (i.e. exogenous salvage) 3.5-6.0 times more than the least translationally efficient RNA (CHSE 214 cells). These data suggest that differential nucleotide supply, between intracellular synthesis and exogenous salvage, constitutes the area of pre-translational flexibility exploited to maintain RNA synthesis as a fixed energetic cost component of protein synthesis.

Animals↗
PubMed2000

Laser Doppler flowmeter measurement of relative gingival and forehead skin blood flow in light and heavy smokers during and after smoking.

AIM: To determine the effect of the smoking experience on relative blood flow in gingiva and to compare this to skin. METHOD: A laser Doppler flowmeter was used to record relative blood flow to healthy gingiva and to forehead skin in smokers and non-smoking controls. Smoking status was verified by quantitative analysis of serum cotinine. Continuous measurements were made over sequential periods with the subject at rest, during a sham smoking exercise, during smoking of a standard research cigarette (2R1, University of Kentucky) for 5 min and throughout a subsequent recovery period. Non-smoking controls sham smoked during the equivalent 5 minute smoking period. RESULTS: No significant differences with respect to the proportional changes of relative gingival blood flow between time points were observed between the groups. However, between-group comparisons of relative blood flow revealed a significant increase in the relative blood flow to the forehead skin of light smokers (serum cotinine < or =60 ng/ml; n=6), when compared to heavy smokers (serum cotinine > or = 100 ng/ml; n=9) or to non-smokers (serum cotinine < or = 10 ng/ml; n=6), 2 min following the smoking experience (p = 0.007). CONCLUSION: The results do not seem to support the theory that tobacco smoking causes localised vasoconstriction in the periodontal tissues in humans. These data show that smoking causes an acute increase in relative blood flow in forehead skin in light smokers compared to heavy smokers, suggesting a potential induction of tolerance in regular users of tobacco.

Adult↗
PubMed2000

Circulating concentrations of C-reactive protein and total sialic acid in tobacco smokers remain unchanged following one year of validated smoking cessation.

BACKGROUND: Elevated plasma concentrations of C-reactive protein (CRP) and total sialic acid (TSA) have been associated with increased cardiovascular risk. Additionally, levels of both CRP and TSA have been reported to be significantly elevated in smokers. However, it is not clear if the raised TSA and CRP levels noted in smokers are directly attributable to the smoking experience, or if they may be elevated due to a secondary mechanism(s), such as smoking-induced tissue inflammation. SUBJECTS AND METHODS: We measured the plasma concentration of CRP and TSA in a group of smokers at baseline and following one year of validated smoking cessation (n = 30) and in a control group of tobacco users who continued to smoke over the year (n = 30). RESULTS: The baseline concentration of TSA and CRP was 67.2 mg dL(-1) and 1.91 mg L(-1), respectively (n = 60). No significant dose-dependent relationship was noted between baseline CRP or TSA concentration and either plasma cotinine, expired-air CO or daily cigarette consumption. There was no difference in the mean change in CRP level in the quitters over one year (- 0.2 mg L(-1)) compared to the continuing smokers (+ 0.5 mg L(-1)), P = 0.80, or in the change in concentration of TSA in the quitters (- 2.7 mg dL(-1)) compared to the continuing smokers (+ 0.4 mg dL(-1)), P = 0.26. CONCLUSIONS: As the circulating concentrations of both CRP and TSA remain unchanged following one year of smoking cessation, these results would suggest that the elevated levels noted in smokers are not directly attributable to tobacco use and are more likely to be elevated due to a secondary process that is yet to be established.

Adult↗
PubMed2000

Relationship between nutritionally-mediated placental growth restriction and fetal growth, body composition and endocrine status during late gestation in adolescent sheep.

The aim was to investigate the consequences of nutritionally-mediated placental growth restriction on fetal organ growth, conformation, body composition and endocrine status during late gestation. Embryos recovered from superovulated adult ewes inseminated by a single sire were transferred in singleton to the uterus of peripubertal adolescent recipients. Post-transfer, adolescent dams were offered a high (H) or moderate (M) level of a complete diet to promote rapid or moderate maternal growth rates, respectively (n=7 per group). After day 100 of gestation the feed intake of the M dams was adjusted weekly to maintain body condition score. Liveweight gain during the first 100 days of gestation was 301+/-24 and 90+/-4.6 g/day for the H and M groups, respectively. Maternal plasma concentrations of insulin, IGF-I and urea were significantly higher and non-esterified fatty acid concentrations significantly lower in H compared with M dams prior to slaughter on day 128 of gestation. At this stage of gestation, total placentome weight was 50 per cent lower in H compared with M groups (P< 0.001) and was associated with a 37 per cent reduction in fetal weight (P< 0.01). All variables of fetal conformation and absolute fetal organ weights, with the exception of the adrenal glands, were lower (P< 0. 05) in the fetuses from H intake dams. However, relative fetal organ weights expressed as g/kg fetal body weight, with the exception of the gut, were not influenced by maternal dietary intake. Furthermore, fetal weight but not maternal nutritional group were predictive of individual organ weight for all organs dissected. Together these results imply that growth restriction in the fetuses derived from H intake dams was largely symmetrical. Fetal plasma concentrations of insulin, IGF-I and glucose were attenuated (P< 0.05) in fetuses from H compared with M groups. The lower fetal body weight in the former group was associated with a reduction in absolute but not relative crude protein (P< 0.01) and fat content (P< 0.05). Total fetal liver glycogen content but not concentration was (P< 0.05) reduced in H versus M groups. The lower mass of both the placenta and fetal liver was due to a reduction in cell number rather than an alteration in cell size. Thus, over-nourishing adolescent sheep is associated with a major restriction in placental growth which mediates a gradual slowing of fetal growth during the final third of pregnancy.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Maternal protein deficiency causes hypermethylation of DNA in the livers of rat fetuses.

Maternal protein deficiency during pregnancy is associated with changes in glucose tolerance and hypertension in the offspring of rats. In this study the growth of rat fetuses was examined when the dams were fed diets containing 18% casein, 9% casein or 8% casein supplemented with threonine. The extra threonine was added to reverse the decrease in circulating threonine concentrations that occurs when pregnant rats are fed protein-deficient diets. The fetuses of the group fed the low protein diet supplemented with threonine were significantly smaller than those of the control group and not significantly different from those fed low protein. Homogenates prepared from the livers of dams fed the diet containing 9% casein oxidized threonine at approximately twice the rate of homogenates prepared from dams fed the diet containing 18% casein. We conclude that circulating levels of threonine fall as a consequence of an increase in the activity of the pathway that metabolizes homocysteine produced by the transulfuration of methionine. Serum homocysteine was unaffected in the dams fed low protein diets compared with controls, but was significantly greater in dams fed the low protein diet supplemented with threonine. Elevated levels of homocysteine are associated with changes in the methylation of DNA. The endogenous methylation of DNA was greater than that of controls in the livers of fetuses from dams fed the 9% protein diets and increased further when the diet was supplemented with threonine. Our results suggest that changes in methionine metabolism increase homocysteine production, which leads to changes in DNA methylation in the fetus. An increase in maternal homocysteine may compromise fetal development, leading to the onset of glucose intolerance and hypertension in adult life.

Animals↗
PubMed2000

Effects of a multicomponent intervention on functional outcomes and process of care in hospitalized older patients: a randomized controlled trial of Acute Care for Elders (ACE) in a community hospital.

BACKGROUND: Older persons frequently experience a decline in function following an acute medical illness and hospitalization. OBJECTIVE: To test the hypothesis that a multicomponent intervention, called Acute Care for Elders (ACE), will improve functional outcomes and the process of care in hospitalized older patients. DESIGN: Randomized controlled trial. SETTING: Community teaching hospital. PATIENTS: A total of 1,531 community-dwelling patients, aged 70 or older, admitted for an acute medical illness between November 1994 and May 1997. INTERVENTION: ACE includes a specially designed environment (with, for example, carpeting and uncluttered hallways); patient-centered care, including nursing care plans for prevention of disability and rehabilitation; planning for patient discharge to home; and review of medical care to prevent iatrogenic illness. MEASUREMENTS: The main outcome was change in the number of independent activities of daily living (ADL) from 2 weeks before admission (baseline) to discharge. Secondary outcomes included resource use, implementation of orders to promote function, and patient and provider satisfaction. RESULTS: Self-reported measures of function did not differ at discharge between the intervention and usual care groups by intention-to-treat analysis. The composite outcome of ADL decline from baseline or nursing home placement was less frequent in the intervention group at discharge (34% vs 40%; P = .027) and during the year following hospitalization (P = .022). There were no significant group differences in hospital length of stay and costs, home healthcare visits, or readmissions. Nursing care plans to promote independent function were more often implemented in the intervention group (79% vs 50%; P = .001), physical therapy consults were obtained more frequently (42% vs 36%; P = .027), and restraints were applied to fewer patients (2% vs 6%; P = .001). Satisfaction with care was higher for the intervention group than the usual care group among patients, caregivers, physicians, and nurses (P < .05). CONCLUSIONS: ACE in a community hospital improved the process of care and patient and provider satisfaction without increasing hospital length of stay or costs. A lower frequency of the composite outcome ADL decline or nursing home placement may indicate potentially beneficial effects on patient outcomes.

Activities of Daily Living↗
PubMed2000

Functional status before hospitalization in acutely ill older adults: validity and clinical importance of retrospective reports.

OBJECTIVES: Retrospective reports of patients' functional status before hospital admission are often used in longitudinal studies and by clinicians caring for hospitalized patients. However, the validity of these reports has not been established. Our aim was to examine the validity of retrospective reports by testing hypotheses about the relationships these measures would have with other clinical measures if they were valid. DESIGN: A prospective cohort study. PARTICIPANTS AND SETTING: A total of 2877 older patients (mean age 81, 36% women) hospitalized on the general medical service at two hospitals. For 1953 of the subjects, the patient was the primary respondent, whereas for 924 subjects, a surrogate was the primary respondent. MEASUREMENTS: Shortly after hospital admission, patients or surrogates reported whether the patient was independent in each of five activities of daily living (ADLs) on admission and at baseline 2 weeks before admission. Outcome measures included reported independence in each ADL 3 months after the hospitalization and survival to 1 year. RESULTS: Patients' retrospective reports of their ADL function 2 weeks before admission had a clinically plausible relationship with ADL function at the time of admission, in that patients independent in an ADL on admission rarely reported they were dependent in that ADL 2 weeks before admission (range 2-6%). Surrogates were somewhat more likely than patients to report that patients independent on admission were dependent 2 weeks before admission (range 5-14%). Retrospective reports of prehospitalization ADL function demonstrated strong evidence of predictive validity for both patients' and surrogates' reports. For example, among patients dependent in bathing on admission, patients who were reported as independent 2 weeks before admission were much more likely than those reported as dependent 2 weeks before admission to be independent 3 months after hospitalization (68% vs 20%, P < .001 for patient respondents; 30% vs 5%, P < .001 for surrogate respondents). Similarly, among patients dependent in bathing on hospital admission, survival 1 year after hospitalization was much higher in patients who were independent in bathing 2 weeks before admission than patients who were dependent 2 weeks before admission (76% vs 59%, P < .001 for patient respondents; 60% vs 45%, P < .001 for surrogate respondents). Results were similar for each of the other four ADLs. In a logistic regression model controlling for the number of ADLs reported as dependent on admission, the number of ADLs reported as dependent 2 weeks before admission was significantly associated with 1-year mortality among both patient (odds ratio (OR) = 1.39 per dependent ADL, 95% confidence interval (CI) - 1.26-1.54) and surrogate (OR = 1.14, 95% CI = 1.06-1.24) respondents. CONCLUSIONS: Hospitalized patients' assessments of their ability to perform ADLs before their hospitalization have evidence of face and predictive validity. These measures are strong predictors of important health outcomes such as functioning and survival. In particular, among patients dependent in ADL function on hospital admission, these results highlight the prognostic importance of inquiring about the patient's functional status before the onset of the acute illness.

Activities of Daily Living↗
PubMed2000

A 5-year prospective study of Astra single tooth implants.

AIM: To evaluate the AstraTech Implant ST (Molndal, Sweden) for single tooth replacement clinically and radiographically after 5 years in function. SUBJECTS AND METHOD: Fifteen patients (age range 16 to 48) with missing maxillary anterior teeth (6 central incisors, 8 laterals, 1 bicuspid) had four 13 mm and eleven 15 mm single tooth implants provided. All patients were seen at 4- to 6-monthly intervals for oral hygiene maintenance. Periapical radiographs using Rinn holders and a long cone technique were taken at the crown insertion and after 1 year, 3 and 5 years. RESULTS: No implant losses were observed in 14 of the 15 patients available for evaluation. No abutment screw loosening or soft tissue problems were observed. At crown insertion the mean bone level was 0.46 +/- 0.55 to 0.48 +/- 0.56 mm apical to the top of the implant neck and there were no statistically significant changes in the radiographic bone level over the 5 years of the study (0.36 +/- 0.37 to 0.43 +/- 0.46 mm at year 5). One crown was recemented after 18 months in function and 1 crown was replaced because of a fracture to the porcelain incisal edge. CONCLUSION: The Astra Tech Implants ST were highly successful in single tooth replacement and bone levels during 5 years of function were stable.

Adolescent↗