Chlorhexidine and preservation of sound tooth structure in older adults. A placebo-controlled trial.

The Trial to Enhance Elderly Teeth Health (TEETH) was designed to test the impact of regular rinsing with a 0.12% chlorhexidine (CHX) solution on tooth loss, and the causes of tooth loss (caries, periodontal disease and trauma) were also investigated. This paper reports on the effectiveness of a 0.12% CHX solution for controlling caries using a tooth surface (coronal and root) survival analysis. A total of 1,101 low income elders in Seattle (United States) and Vancouver (Canada), aged 60-75 years, were recruited for a double-blind clinical trial and assigned to either a CHX (n = 550) or a placebo (n = 551) mouth rinse. Subjects alternated between daily rinsing for 1 month, followed by weekly rinsing for 5 months. All sound coronal and root surfaces at baseline were followed annually for up to 5 years. At each follow-up examination, those tooth surfaces with caries, restored, or extracted were scored as 'carious'. The hazard ratio associated with CHX for a sound surface to become filled, decayed, or extracted was 0.87 for coronal surfaces (95% confidence interval: 0.71-1.14, p = 0.20) and 0.91 for root surfaces (95% confidence interval: 0.73-1.14, p = 0.41). These findings suggest that regular rinsing with CHX does not have a substantial effect on the preservation of sound tooth structure in older adults.

Periodontitis and perceived risk for periodontitis in elders with evidence of depression.

BACKGROUND: Depression and periodontitis are common conditions in older adults. There is some evidence that these two conditions may be related. AIMS: To study a population of dentate elders and assess the prevalence of depression, self-assessment of risk for periodontitis and tooth loss, in relation to periodontal disease status. MATERIAL AND METHODS: Data were obtained from 701 older subjects (mean age 67.2 years (SD+/-4.6), of whom 59.5% were women. Self-reports of a diagnosis of depression, scores of the Geriatric Depression Scale (GDS), and self-assessment of risk for future tooth loss and periodontitis were compared with a diagnosis of periodontitis based on probing depth, and bone loss assessed from panoramic radiographs. Other systemic diseases and smoking habits were also determined and studied in relation to depression. RESULTS: A history of depression was reported by 20% of the subjects. GDS scores >/=8 were reported by 9.8% of the elders. Periodontitis was identified in 48.5% of the subjects. Depression was associated with heart attack (p<0.05), stroke (p<0.01), high blood pressure (p<0.02), all combined cardiovascular diseases (p<0.001), chronic pain (p<0.01), osteoarthritis (p<0.001), and osteoporosis (p< 0.001) but not with periodontitis (p=0.73). Subjects with depression had a higher self-reported risk score for future tooth loss (p<0.02). No group difference emerged for self-perceived risk for periodontitis. Logistic regression analysis demonstrated that a past history of tooth loss (p<0.001), self-perceived risk for periodontitis (p<0.02), the number of years with a smoking habit (p<0.02), and male gender (p<0.02) were associated with a diagnosis of periodontitis but neither measure of depression could be included in an explanatory model for periodontitis. CONCLUSIONS: Evidence of depression (self-report or by GDS) is not associated with risk for periodontitis in older subjects but is associated with tooth loss and chronic conditions associated with pain.

Assessment of periodontal conditions and systemic disease in older subjects.

BACKGROUND: An increased risk for periodontitis has been associated both with type-1 or insulin dependent diabetes (IDDM) and with type-2 or non-insulin dependent diabetes (NIDDM). AIMS: 1) To describe and analyze periodontal conditions in older low-income ethnic diverse subjects with or without a diagnosis of diabetes. 2) To assess to what extent diabetes mellitus is associated with periodontal status, and 3) how periodontitis ranks as a coexisting disease among other diseases in subjects with diabetes mellitus. MATERIAL AND METHODS: Radiographic signs of alveolar bone loss were studied in 1101 older subjects 60-75 years old (mean age 67.6, SD+/-4.7). The number of periodontal sites and the proportions of teeth with probing depth (PD) > or =5 mm, clinical attachment levels (CAL) > or =4 mm were studied in a subset of 701 of the subjects. RESULTS: IDDM was reported by 2.9% and NIDDM by 9.2% of the subjects. The number of remaining teeth did not differ by diabetic status. The number of sites with PD > or =5 mm and the proportion of PD with > or =5 mm was significantly smaller in the non-diabetic group (chi2=46.8, p<0.01, and chi2=171.1, p<0.001, respectively). Statistical analysis failed to demonstrate group differences for the number and proportions of sites with CAL > or =4 mm and for radiographic findings of alveolar bone loss. Combining all periodontal parameters revealed that the Mantel-Haenszel common odds of having IDDM/NIDDM and periodontitis was 1.8 : 1 (95% CI: 1.1-3.1, p<0.03). The common odds ratio estimate of an association between heart disease and diabetes was 3.6 : 1 (95% CI: 2.1-2.6, p<0.001). CONCLUSIONS: Probing depth differences between IDDM/NIDDM vs. non-diabetic subjects may reflect the presences of pseudo-pockets and not progressive periodontitis in many subjects with diabetes mellitus. Periodontitis is not a predominant coexisting disease in older subjects with diabetes mellitus.

Assessment of periodontal conditions and systemic disease in older subjects. I. Focus on osteoporosis.

BACKGROUND: Osteoporosis (OPOR) is a common chronic disease, especially in older women. Patients are often unaware of the condition until they experience bone fractures. Studies have suggested that OPOR and periodontitis are associated diseases and exaggerated by cytokine activity. Panoramic radiography (PMX) allows studies of mandibular cortical index (MCI), which is potentially diagnostic for OPOR. AIMS: i). To study the prevalence of self-reported history of OPOR in an older, ethnically diverse population, ii). to assess the agreement between PMX/MCI findings and self-reported OPOR, and iii). to assess the likelihood of having both a self-reported history of OPOR and a diagnosis of periodontitis. MATERIALS AND METHODS: PMX and medical history were obtained from 1084 subjects aged 60-75 (mean age 67.6, SD +/- 4.7). Of the films, 90.3% were useful for analysis. PMXs were studied using MCI. The PMXs were used to grade subjects as not having periodontitis or with one of three grades of periodontitis severity. RESULTS: A positive MCI was found in 38.9% of the subjects, in contrast to 8.2% self-reported OPOR. The intraclass correlation between MCI and self-reported OPOR was 0.20 (P < 0.01). The likelihood of an association between OPOR and MCI was 2.6 (95%CI: 1.6, 4.1, P < 0.001). Subjects with self-reported OPOR and a positive MCI had worse periodontal conditions (P < 0.01). The Mantel-Haentzel odds ratio for OPOR and periodontitis was 1.8 (95%CI: 1.2, 2.5, P < 0.001). CONCLUSIONS: The prevalence of positive MCI was high and consistent with epidemiological studies, but only partly consistent with a self-reported history of osteoporosis with a higher prevalence of positive MCI in Chinese women. Horizontal alveolar bone loss is associated with both positive self-reported OPOR and MCI.

Assessment of periodontal conditions and systemic disease in older subjects. II. Focus on cardiovascular diseases.

BACKGROUND: Panoramic radiographs (PMX)s may provide information about systemic health conditions. AIMS: i). To study clinical periodontal conditions and collect self-reported health status in a cohort of 1084 older subjects; ii). to study signs of alveolar bone loss and carotid calcification from panoramic radiographs obtained from these subjects; and iii). to study associations between study parameters. MATERIAL AND METHODS: PMXs from 1064 adults aged 60-75 (mean age 67.6, SD +/- 4.7) were studied. Signs of alveolar bone loss, vertical defects, and molar furcation radiolucencies defined periodontal status. Medical health histories were obtained via self-reports. Signs of carotid calcification were identified from panoramic radiographs. RESULTS: The PMX allowed assessment of 53% of the films (Seattle 64.5% and Vancouver 48.4%). A self-reported history of a stroke was reported by 8.1% of men in Seattle and 2.9% of men in Vancouver (P < 0.01). Heart attacks were reported by 12% of men in Seattle and 7.2% in Vancouver (N.S.). PMX evidence of periodontitis was found in 48.5% of the subjects, with carotid calcification in 18.6%. The intraclass correlation score for PMX findings of carotid calcification and stroke was 0.24 (95% CI: 0.10-0.35, P < 0.001). The odds ratio for PMX carotid calcification and periodontitis was 2.1 (95% CI: 1.3-3.2, P < 0.001), and for PMX carotid calcification and stroke 4.2 (95% CI: 1.9-9.1, P < 0.001). The associations disappeared when smoking was accounted for. A history of a heart attack was associated with stroke, gender, age, and PMX scores of alveolar bone loss. CONCLUSIONS: PMXs may provide valuable information about both oral conditions and signs of carotid calcification, data that are consistent with self-reported health conditions. Alveolar bone loss as assessed from PMXs is associated with cardiovascular diseases.

Effects of a computerized treatment simulation on patient expectations for orthognathic surgery.

One hundred forty-six patients, ranging in age from 15 to 50 and presenting with a moderate to severe dentofacial disharmony requiring orthodontics and orthognathic surgery, were randomly assigned to 2 preparation strategy groups: standard presurgical consultation with or without a computerized treatment simulation presentation. The demographic profiles of the 2 groups were similar. Viewing a treatment simulation did not have a significant effect on the anticipation of social/interpersonal or general health problems in the first month after surgery. These 2 areas of concern were significantly related to psychological well-being. Psychologically distressed patients, whether or not they saw a simulation, expected significantly more problems in social/interpersonal relations and in general health during the first month after surgery. A treatment simulation presentation did affect patients' overall expectations of problems in the first month after surgery and their concerns about symptom recovery. However, the impact of the presentation was related to the patient's psychological well-being. In the standard presurgical consultation group, the average anticipated level of overall problems and discomfort during recovery was significantly higher for patients who reported elevated psychological distress than for those who did not. In the treatment simulation group, the average level of concern was similar for those patients who reported distress and those who did not. Preparation strategy was not significantly related to the long-term expectation of improvement after treatment. Long-term expectation of treatment improvement was related to psychological distress and gender. Men tended to report similar expectations regardless of psychological well-being, while women who were distressed anticipated significantly more improvement overall, in self-image, and in general health after treatment than women who were not distressed.

Socioeconomic factors that affect international caries levels.

UNLABELLED: Health policy makers have examined the impact of economic policies and a nation's social development on the health of its population. OBJECTIVES: The purpose of this research was to investigate the association between health care expenditures, socioeconomic factors, and caries levels in 109 countries representing an array of social and economic conditions, and to determine how such factors are related to caries experience at different levels of economic development. METHODS: Countries were divided into established market economies and three groups of developing nations, based on their GNP (high, medium, low income). Total health expenditures as percent GDP and as US dollars per capita, public expenditures and aid flow as percent of total health expenditures, dentists per 100,000 population, per capita sugar consumption, and urbanization of the population were compared among these countries. Correlations between these variables, and decayed, missing and filled teeth (DMFT) of 12-year-olds in these countries were assessed. RESULTS: The highest correlations were found between DMFT and public expenditures, sugar consumption, and urbanization. Highly significant differences emerged across nation groups by stages of development on several variables. CONCLUSIONS: The findings suggest that it is important to consider the stage of development of a given country when planning caries prevention policies and programs. Such a contextual approach is more likely to be successful in reducing caries levels.

Successful aging: implications for oral health.

The past few years have seen a growing emphasis in gerontology on the concept of "successful" or "robust" aging. This represents a major paradigm shift in the field from a focus on declines in physical and social functioning, assumptions of the aging process as a downward spiral, and studies on how to manage these declines. Leading the way toward this new perspective on aging, the MacArthur Studies of Successful Aging asked the fundamental question: "What genetic, biomedical, behavioral, and social factors are crucial to maintaining health and functional capacities in the later years?" These studies examined longitudinally a large cohort of independent elders on several physical, cognitive, emotional, and social parameters. Other researchers have focused on the theme of robust aging; however, common predictors have emerged, such as remaining active physically and cognitively, maintaining social contacts, and avoiding disease. This research is timely, given the expanding population of the oldest old, and with successive cohorts demonstrating the "compression of morbidity" phenomenon. Such a paradigm shift is critical in geriatric dentistry as well, where successful aging is evident in the growing number of older adults who have retained their natural dentition into advanced old age. This presentation draws parallels between successful aging at the systemic and oral health levels, with illustrations from epidemiologic studies that demonstrate trends in improved health and quality of life among newer cohorts of older adults.

Caries prevention in a community-dwelling older population.

A clinical trial was conducted to compare the effect of different caries-preventive strategies on caries progression in lower-income, ethnically diverse persons 60 years of age and older. Two hundred and ninety-seven subjects were randomized into one of five experimental groups. Group 1 received usual care from a public health department or a private practitioner. Group 2 received an educational program of 2 h duration implemented twice a year. Group 3 received the educational program plus a 0.12% chlorhexidine rinse weekly. Group 4 received the education and chlorhexidine interventions and a fluoride varnish application twice a year. Group 5 received all the above interventions as well as scaling and root planing every 6 months throughout the 3-year study. A carious event was defined as the onset of a carious lesion, a filling, or an extraction on a surface which was sound at baseline. Two hundred and one subjects remained in the study for the 3-year period. Groups that received usual intraoral procedures (groups 3, 4, and 5) had a 27% reduction for coronal caries events (p = 0.09) and 23% for root caries events (p = 0.15), when compared to the groups that received no intraoral procedures (groups 1 and 2). Routine preventive treatments may have had only a small-to-moderate effect upon caries development.

Comparing the perception of dentists and lay people to altered dental esthetics.

PURPOSE: This study was designed to determine the perceptions of lay people and dental professionals with respect to minor variations in anterior tooth size and alignment and their relation to the surrounding soft tissues. MATERIALS AND METHODS: Smiling photographs were intentionally altered with one of eight common anterior esthetic discrepancies in varying degrees of deviation, including variations in crown length, crown width, incisor crown angulation, midline, open gingival embrasure, gingival margin, incisal plane, and gingiva-to-lip distance. Forty images were randomized in a questionnaire and rated according to attractiveness by three groups: orthodontists, general dentists, and lay people; 300 questionnaires were distributed. RESULTS: The response rate was 88.2% for orthodontists, 51.8% for general dentists, and 60.6% for lay people. The results demonstrated threshold levels of noticeable difference between the varying levels of discrepancy. A maxillary midline deviation of 4 mm was necessary before orthodontists rated it significantly less esthetic than the others. However, general dentists and lay people were unable to detect even a 4-mm midline deviation. All three groups were able to distinguish a 2-mm discrepancy in incisor crown angulation. An incisal plane cant of 1 mm as well as a 3-mm narrowing in maxillary lateral incisor crown width were required by orthodontists and general dentists to be rated significantly less esthetic. Lay people were unable to detect an incisal plane asymmetry until it was 3 mm, or a lateral incisor narrowing until it reached 4 mm. Threshold levels for open gingival embrasure and gingiva-to-lip distance were both at 2 mm for the orthodontic group. Open gingival embrasure became detectable by the general dentists and lay people at 3 mm, whereas gingiva-to-lip distance was classified by these groups as noticeably unattractive at 4 mm. CLINICAL SIGNIFICANCE: The results of this study show that orthodontists, general dentists, and lay people detect specific dental esthetic discrepancies at varying levels of deviation, which may aid the dental professional in making specific treatment recommendations.

Neurosensory changes following orthognathic surgery.

Much variability exists among studies of neurosensory disturbance following facial surgery. This diversity of findings may be a function of the different surgical procedures and measurement methods used. The present study compared 3 methods of assessing neurosensory loss following surgical orthodontics. Two objective tests and 1 subjective test were administered to 24 patients preoperatively and 4 weeks postoperatively. These included measures of 2-point discrimination, pressure-pain thresholds, and perceived sensation changes in specific facial regions. Postoperatively, all patients needed greater separation on the 2-point discrimination test in the lower facial regions, but not in the upper regions. Bilateral sagittal split osteotomy patients, especially males, required greater separation on these lower sites. Pressure-pain thresholds were not significantly impaired in most patients. Those who underwent combined maxillary and mandibular procedures experienced lower thresholds on the lower lip, while bilateral sagittal split osteotomy patients reported lower thresholds on the upper lip. The 2-point discrimination test was consistent with patients' self-ratings of neurosensory problems using facial maps, but the pressure-pain test was not. The majority of patients reported changed sensation in the lower facial regions postoperatively, regardless of surgery type. Examiners were less likely to rate these same facial regions as different in sensory acuity. Male patients were more likely to report sensory loss or pain postoperatively. These findings suggest that self-reports of neurosensory change following orthognathic surgery are consistent with tests of 2-point discrimination and somewhat higher than examiner ratings, but the objective test of pressure-pain thresholds in this study was least sensitive to neurosensory changes.

Oral health and medical status in dentate low-income older persons.

Oral and medical conditions of 295 low-income dentate older persons (17% African-Americans, 14.5% Asians, 11.5% Hispanics, and 57% Caucasians) were studied. The mean age was 72 (SD +/- 6.8; range, 60-91). Oral examinations were performed, stimulated saliva was collected, and interviews were conducted regarding oral health attitudes, knowledge, and behaviors. Past history of restorative care, defined by filled coronal surfaces, differed by ethnicity, with Caucasian elders having most filled surfaces (p < 0.001). Ethnic minority elders had significantly poorer periodontal health (p < 0.001), with the worst conditions in Asians. Low salivary flow (< 0.01 mL/min) was found in 31% using medications known to cause hyposalivation. Frequent diseases were arthritis (46%), hypertension (39%), heart disease (25.2%), and diabetes (8.5%). Hypothyroidism was associated with low flow rate (F = 13.2, p < 0.0003). Seventy percent reported that they had never smoked. Smokers had deeper probing depths (chi 2 = 11.98, p < 0.05) and more gingival recession (F = 8.08, p < 0.001). Women on hormone replacement therapy (HRT) had less calculus (F = 11.33, p < 0.01) and fewer sites with probing depths > 5 mm (F = 8.99, p < 0.003). The present study found few associations between physical and oral health and ethnicity. The benefits of HRT for women's periodontal health and the effects of hypothyroidism on stimulated salivary flow are noteworthy.

Factors associated with caries incidence in an elderly population.

The purpose of this paper was to identify baseline factors associated with future caries development in older adults (age 60+) during a 3-year study period. Poisson regression analysis was used to determine the association between potential risk factors and disease incidence. The significant factors associated with high coronal caries incidence rates were high baseline root DMFS (P<0.001), high counts of mutans streptococci and lactobacilli (P=0.036), male gender (P=0.007), and Asian ethnicity (P=0.002). These factors had small to moderate effects on incidence rates, with relative risk values of approximately 1.2 to 2. The significant factors associated with higher disease incidence on root surfaces were baseline coronal DMFS (marginally significant, P=0.078), high bacterial counts (P=0.002), and Asian ethnicity (P=0.009). The predictive value of the models was low for both coronal and root caries. This result may be because this population had a higher than usual caries incidence rate, making discrimination among these caries-active individuals difficult. The current study affirmed the value of baseline DMFS and salivary variables to modeling caries incidence and introduced ethnicity as a variable useful for the study of dental caries in older adults.

Periodontal effects of a biobehavioral prevention program.

The present study tested preventive regimens in older subjects using dental services sporadically. 297 persons aged 60-90 (mean age 72.8; 43% ethnic minorities), were randomly assigned to either a control group or four interventions with incrementally more complex preventive strategies; behavioral training (group 2), added weekly chlorhexidine rinse (group 3), added semi-annual fluoride varnish (group 4), and added semi-annual prophylaxis (group 5). The control group received dental care as they preferred, primarily emergency care. All subjects were re-examined annually for 3 years. At baseline, 190 (64%) of the subjects were considered at risk for future periodontal disease progression. At baseline there were no group differences for any clinical parameter studied. Gingival bleeding varied between 19% and 23% over time and with no group differences. After 1 year, the greater decrease in probing depth for group 5 approached significance compared to the control group (p<0.06). Clinical attachment levels (CAL) improved in group 5 compared to the control group (p<0.01 for mesio-buccal, p<0.05 for mid-buccal tooth surfaces). The group differences did not persist at year 3. At year 3 in group 1, 9.2% and in group 5, 4.9% subjects lost > or =2.0 mm CAL. 310 teeth (6.5%) were extracted during the study period. A 21% increased risk for tooth loss was found in group 2, a 15% reduced risk in group 3, a 28% reduced risk in group 4, and a 44% reduced risk in group 5 compared to the control group (Wald-statistics robust p-value 0.12). At year 3, the tooth mortality rate in groups 3, 4 and 5 combined was reduced to 59% and significantly lower than groups 1 and 2 together (p<0.04). Self-efficacy was the best predictor of periodontal disease progression (F=7.02, p<0.01). Thus older persons benefited from a preventive oral health care program.

Psychological influences on the timing of orthodontic treatment.

Debates about the "ideal" timing of orthodontic treatment have focused on issues of biologic development and readiness. In this article we examine psychologic issues that should be considered in the decision to initiate orthodontics in the younger child or to wait until adolescence or later. Psychologic development during the preadolescent and adolescent stages may influence the child's motive for, understanding of, and adherence to treatment regimens. Results of a study of some personality characteristics, motives, and aesthetic values of young phase I patients are presented. Questionnaires were completed by 75 children (mean age 10.85 years, 52.1% female, 84% white) and their parents. Children's perceived reasons for treatment were consistent with their parents' reports (chi 2 = 76.08, p < .001); most were referred for crowded teeth (56%) and overbite (17.3%). Although body image and self-concept scores were within the normal range, both children and their parents expected the most improvement in self-image and oral function, with greater expectations by parents on self-image (p < .0001), oral function (p < .0001), and social life (p < .03) than children themselves. Although white and minority children were similar in their self-ratings and expectations from orthodontics, the former were more critical in their aesthetic judgments. They rated faces with crowded teeth (p < .02), overbite (p < .02), and diastema (p < .01) more negatively than did ethnic minorities. These results suggest that younger children are good candidates for Phase I orthodontics, have high self-esteem and body-image, and expect orthodontics to improve their lives. White children who have been referred for Phase I orthodontics appear to have a narrower range of aesthetic acceptability than minority children.

Orthodontic treatment timing: a survey of orthodontists.

There has been much debate with respect to the ideal time to initiate orthodontic treatment. Recent clinical trials have tested the effects of early orthodontic treatment. The purpose of this study was to understand orthodontists' perspectives on the best time to initiate treatment, factors that preclude early treatment, and experiences with compliance or adherence problems among their younger patients. Questionnaires were distributed to 335 practicing orthodontists throughout the United States. Respondents were first asked to indicate the best stage to initiate orthodontic treatment for 41 different types of occlusal deviations. They were then asked what conditions might preclude early orthodontic treatment. After one reminder, 137 questionnaires (41%) were returned. The sample consisted of practitioners with 3 to 52 years of experience and represented 46 different orthodontic training programs; 19% were female. The majority (92%) were in private practice. Among the 41 conditions listed, orthodontists would most likely treat 21 in the early mixed dentition, especially anterior crossbites (> 76%); 13 in the late mixed dentition, especially deepbite (> 60%) and mandibular inadequacy (> 59%); and 4 in either stage. Only two conditions would be treated in later stages (maxillary midline diastema, 43%; and congenitally missing teeth,39%). One third would postpone treating mandibular prognathism until adulthood. Patient variables that precluded treatment were behavior (98%) and compliance (96%) problems. Finances (76%) and family disruptions (57%) were less important deterrents to treatment. Orthodontists' experience with Phase I treatment influenced their decisions (p < 0.01). Orthodontists who have been in practice longer were more likely to treat temporomandibular joint sounds (p < 0.003) and deviations in opening (p < 0.002) than less experienced orthodontists; the latter were more likely to refer such patients to temporomandibular disorder specialists. These findings suggest that early orthodontic intervention is the norm, but practice characteristics affect treatment timing.

Evaluating the validity of probing attachment loss as a surrogate for tooth mortality in a clinical trial on the elderly.

Most periodontal trials are based on the assumption that the superior treatment, as judged by short-term intangible changes in probing attachment levels (the surrogate), is also the treatment most likely to affect tooth mortality. This assumption is valid if: (1) the surrogate is informative about tooth mortality, and (2) the surrogate captures a substantial proportion of the treatment effect on tooth mortality (e.g., > 50% or 75%). The goal of this study was to evaluate whether both conditions were satisfied in a randomized controlled trial (RCT) of elders at high risk for dental diseases. The results suggested that the first condition for a valid surrogate was satisfied: Both one- and two-year changes in probing attachment level were informative about tooth mortality risk. A 1-mm loss measured over a one-year period was associated with a 56% increased tooth mortality risk (relative risk = 1.56; 95% confidence interval, 1.08 to 2.26; p = 0.017); a 1-mm loss measured over a two-year period was associated with a 102% increased risk for tooth mortality (relative risk = 2.02; 95% confidence interval, 1.26 to 3.25; p = 0.004). The second condition necessary for a valid surrogate could not be confirmed in the present trial. With 95% confidence, it was concluded that one-year changes in probing attachment level measurements did not capture a significant proportion of the treatment effect (point estimate, 6%; 95% confidence interval;-38% to 53%). No useful statements could be made regarding the proportion of treatment effect captured by two-year changes, due to the width of the confidence interval (point estimate, 18%; 95% confidence interval;-151% to 140%). It is concluded that (1) the evidence surrounding the one-year change in probing attachment level indicates that it can be ruled out as being anything more than a weak surrogate marker for tooth mortality, and (2) further research is required to study the validity of two-year change in probing attachment level as a surrogate marker. Due to characteristics of the population and the treatments investigated, the generalizability of these findings to other RCTs is questionable.

The effects of simple interventions on tooth mortality: findings in one trial and implications for future studies.

The purpose of this report was to use a particular clinical trial, the Preventive Geriatric Trial (PGT), as a starting point to discuss whether treatment efficacy can be evaluated by means of tooth mortality. In the PGT, 296 subjects were recruited and randomly assigned to five treatment groups: (1) usual procedures (UP); (2) UP + a cognitive-behavioral intervention (CB); (3) UP + CB + weekly chlorhexidine rinse (CHX); (4) UP + CB + CHX + semi-annual fluoride varnish (F); and (5) UP + CB + CHX + F + semi-annual prophylaxis, including scaling (P). Exploratory analyses revealed that tooth mortality after the 1st year was lower in treatment groups 3, 4, and 5 than in groups 1 and 2. A one-year exposure resulted in a 45% reduction in tooth mortality (p < 0.05); a two-year exposure resulted in a 59% reduction (p-value < 0.04). The PGT findings suggested that it is possible to design trials based on clinically relevant endpoints, such as tooth mortality. For the detection of moderate treatment effects, such trials could take the form of Large, Simple Trials (LST), where many subjects are recruited with minimally restrictive entry criteria, and data are collected only on essential baseline characteristics and tooth mortality. LSTs have provided "reliable answers to important clinical questions" for other chronic diseases, and several arguments suggest that they could play a similar critical role in dental research: (1) Periodontitis and caries are among the most common and costly chronic diseases affecting humans, and the identification of even moderately effective treatments by LSTs can have a large socio-economic impact; (2) the identification of low-cost widely practicable treatments that lend themselves to be investigated in LSTs is likely to benefit more people than the identification of high-cost complex treatments; and (3) tooth mortality is simple to assess and more relevant than the unvalidated surrogate endpoints that have largely failed for more than 20 years to provide reliable answers to certain controversial issues regarding treatment efficacy. The cost of not reliably establishing the safety and the efficacy of treatments may be far greater than the cost of conducting LSTs.

Longitudinal evaluation of a bone resorption marker in elderly subjects.

The variability over time in the excretion of a bone resorption metabolite (collagen type I N-telopeptide crosslink, NTx) was evaluated in a cohort of community-dwelling elderly men and women (mean age 73 years). Three annual 24-h urine samples were collected. NTx concentration was measured using an established ELISA. Total (24-h) NTx excretion as well as Ntx/creatinine concentration were compared. Men had a significantly lower excretion of NTx/creatinine than women who were not on hormone replacement therapy. Overall, the within-subject long-term coefficient of variability for Ntx/creatinine was 26%. The correlation coefficient between the samples taken a year apart was higher for the 24-h NTx excretion (r = 0.66) than for the 24-h creatinine excretion (r = 0.51). The consistency of NTx excretion over time was also evaluated in all 93 subjects with three yearly samples using Kendall's rank correlation method; the resulting coefficient of concordance was 0.78 (significant at the 0.01 level). These results indicate that while NTx excretion varies in subject samples collected over a period of 2 years, this variability is not much greater than the daily variation reported for NTx and other bone metabolism markers. The relative reproducibility of NTx excretion over time in this age group was also evident in the coefficient of concordance. The results provide support for stratifying subjects according to level of bone resorption and identifying those subjects with high turnover who may be at greater risk of osteoporotic fracture.