Maternal mental health and offspring's IQ: Evidence from two Brazilian birth cohorts.

Maternal mental health during different stages of life can have a significant impact on a child's cognitive development. This study aimed to investigate the association between maternal CMD at two distinct stages of the offspring's life (at 3 months and 11 years) and their IQ scores at 6 and 18 years across two birth cohorts. The study utilized data from two Brazilian birth cohorts: the 1993 cohort (full sample: N = 3719, subsample: N = 436), and the 2004 Pelotas Birth Cohort (N = 3440). IQ assessments were conducted at ages 18 and 6, employing the Wechsler Adult Intelligence Scale, third version (WAIS-III), and Wechsler Intelligence Scale for Children, third version (WISC-III), respectively. The presence of maternal CMD at 3 months and 11 years of age was evaluated using the Brazilian version of the Self-Reporting Questionnaire (SRQ-20). After adjustment, participants whose mothers experienced CMD at 3 months had average IQ scores 1.74 (95 % CI: -2.83 to -0.67) and 2.79 (95 % CI: -5.54 to -0.04) points lower at ages 6 (2004 cohort) and 18 (1993 cohort subsample), respectively. Furthermore, in the 1993 cohort (both full and subsample), maternal CMD at 11 years was associated with lower IQ scores at age 18. Understanding the mechanisms underlying this association, emphasized by these findings, is crucial for promoting children's cognitive development, educational achievement, and overall well-being.

Ultra-processed food consumption and dental caries in adolescents from the 2004 Pelotas Birth Cohort study.

OBJECTIVE: To investigate the relationship between ultra-processed food (UPF) consumption and dental caries in adolescents. METHODS: Data from 996 adolescents aged 12-13 years who participated in an oral health sub-study of the 2004 Pelotas Birth Cohort in southern Brazil were analysed. The main exposure was daily UPF consumption at age 10-11 years, measured by a food frequency questionnaire containing 24 UPF items defined based on the NOVA system. UPF consumption was calculated in frequency, grams and calories, in general and for six types of food (biscuits, savoury snacks and sugar-sweetened cereals; ultra-processed meats and fats; sweets; fast food and instant noodles; soft drinks and artificially flavoured drinks; and sweetened milk and powdered chocolate). The outcome was dental caries, measured according to the decayed, missing and filled indexes (DMFS and dmfs) at age 12-13 years. Poisson regression models were used to analyse the association between UPF consumption and dental caries, adjusting for socioeconomic and demographic variables, dental visits and oral hygiene. RESULTS: Overall, the daily UPF consumption in frequency, grams and calories was associated with caries. The findings were consistent for UPF consumption for all six food groups. The higher the UPF consumption, the higher the probability of having caries in adolescence. The associations between ultra-processed meats and fats, and fast food and instant noodles intake with dental caries alert to the cariogenic potential of such UPF foods. CONCLUSION: Ultra-processed food consumption was associated with greater caries burdens in young adolescents. The findings reinforce the need for interventions and public policies to reduce UPF consumption in adolescence.

Validity of partial protocols to evaluate the prevalence of developmental defects of enamel in permanent dentition: a birth cohort study in Southern Brazil.

OBJECTIVES: To evaluate the validity of partial protocols (PP) to assess the prevalence of developmental defects of enamel (DDE) in permanent teeth and identify the strength of the association between DDE and some risk factors, using PP compared to the full-mouth (FM) exam. MATERIALS AND METHODS: This study was conducted in a population-based birth cohort of children born in 2004 in Pelotas, Southern Brazil. Socioeconomic, demographic, pre-, per-, and post-birth variables were collected. A subsample of 994 children was clinically examined for DDE in 2017, using the modified DDE index, using the "full- mouth" (FM) protocol. After FM had been performed, a dataset was created. Two different partial protocols (PP) were simulated from FM data: "only buccal surfaces (BS)" and "incisive and molars only (IM)." Sensitivity, absolute and relative bias, and inflation factors were calculated. RESULTS: For any DDE, FM had prevalence of 40.8%. The prevalence of DDE was 38.8% and 36.0%, for BS and IM protocols, respectively. When tested for any DDE, PP "BS" and "IM" showed high sensitivity. The underestimation of the true prevalence did not exceed 6.9% for PP "BS" and 16.1% for PP "IM." All protocols showed similar magnitude of association with the selected risk factors. CONCLUSION: Both PP "BS" and "IM" can be used to estimate the prevalence of DDE in epidemiological studies. CLINICAL RELEVANCE: Oral health surveys now have the option of using PP to collect DDE prevalence and investigate their association with risk factors, being less time-consuming, expensive, and labor intensive.

Influence of maternal excess weight before pregnancy on breast-feeding and weaning: pooled analyses of four population-based cohorts born between 1982 and 2015.

To investigate the associations of maternal excess weight before pregnancy with (1) weaning at 3 months of age, (2) duration of exclusive breast-feeding at 6 months of age, (3) duration of any breast-feeding at 12 months of age and (4) to compare the magnitude of these associations over four decades. Data were from participants in the Pelotas (Brazil) Birth Cohorts born in 1982 (n 5334), 1993 (n 1442), 2004 (n 4092) and 2015 (n 4102). Maternal pre-pregnancy weight was collected after the delivery and breast-feeding status was assessed when children were 3 and 12 months old. Only in the most recent cohort (2015), women with excess weight (BMI ≥ 25 kg/m2) before pregnancy had higher risk of discontinuing exclusive breast-feeding within the first 6 months postpartum than women with normal weight (hazard ratio = 1·22 (95 % CI 1·15, 1·30)). Duration of any type of breast-feeding until 12 months of age was not affected by pre-pregnancy weight. Excess weight before pregnancy is associated with exclusive breast-feeding only in the most recent birth cohort coinciding with increases in excess weight and breast-feeding over time.

Corrigendum: Trends and Inequalities in Unplanned Pregnancy in Three Population-Based Birth Cohorts in Pelotas, Brazil.

[This corrects the article DOI: 10.1007/s00038-020-01505-0.].

Trends and inequalities in unplanned pregnancy in three population-based birth cohorts in Pelotas, Brazil.

OBJECTIVES: To assess time trends in unplanned pregnancy, stratified by sociodemographic status, reproductive history, and inequalities in family income and women's skin color, in Pelotas, Brazil. METHODS: Data from mothers of participants of the 1993 (N = 5264), 2004 (N = 4243), and 2015 (N = 4268) Pelotas birth cohorts were analyzed. Unplanned pregnancy was investigated in the perinatal period, with tests to assess changes over time among different sociodemographic and reproductive history subgroups and inequalities as a function of family income and skin color. RESULTS: The prevalence of unplanned pregnancy was 62.7% (3299/ 5264), 65.9% (2794/ 4243), and 52.2% (2226/ 4268) in the 1993, 2004, and 2015 cohorts, respectively. Black or brown women and women of lower socioeconomic status had a higher prevalence of unplanned pregnancy in all cohorts. The overall rate of unplanned pregnancy decreased over time in most subgroups. Inequality as a function of family income and skin color increased during the time frame of assessment. CONCLUSIONS: The prevalence of unplanned pregnancies decreased in the period analyzed, but it is still unjustifiably high. Efforts aimed at reducing unplanned pregnancy are vital and will require special attention to the most vulnerable groups.

Maternal and child-health outcomes in pregnancies following Assisted Reproductive Technology (ART): a prospective cohort study.

BACKGROUND: Studies comparing the outcome of spontaneous versus assisted reproductive technologies (ART) pregnancies report heterogeneous results. Despite the success of ART to overcome infertility, concern is growing regarding both its safety and its effect on maternal and child health. The objective of this study was to compare maternal and child-health outcomes after ART relative to natural conception. METHODS: A population-based birth cohort study was carried out among pregnant women expected to deliver in 2015 in Pelotas, southern Brazil. Maternal outcomes included pregnancy complications and gestational weight gain. Gestational age, weight, intrauterine growth restriction, length and head circumference, and 1-min and 5-min Apgar, as well as health problems at birth and breastfeeding were defined as offspring outcomes. Statistical analyses were performed using linear and logistic regression. G-formula was used to perform mediation analysis. RESULTS: The study included 4252 babies born by spontaneously pregnancies and 23 babies born after ART. Adjusted analyses showed that children conceived from ART presented lower means of gestational age (p = 0.001), birth weight (p = 0.002), length (p < 0.001), and head circumference at birth (p = 0.02). However, more than 90% of the effect of ART over these outcomes was mediated by multiple pregnancy. CONCLUSION: Our findings suggest that the possible negative effect on the child-health outcomes is due mainly to the higher incidence of multiple pregnancies and not because of ART. The reasons for the increase in adverse pregnancy outcomes associated with ART singleton pregnancies are still uncertain and warrants further research. Further large-population studies are needed to confirm these results.

Reasons for direct restoration failure from childhood to adolescence: A birth cohort study.

OBJECTIVES: The aim of this study was to assess the prevalence of direct restorations in posterior teeth in children aged 12, from a birth cohort, and to test the association between the quality of the restorations and individual variables experienced in the life cycle. METHODS: All live-born children in Pelotas, in 2004, were prospectively investigated and a representative sample was assessed for oral conditions at ages 5 and 12. The outcome was the quality of the restoration (satisfactory/unsatisfactory). Independent variables included socioeconomic, behavioral and oral health characteristics at the individual level and the size of cavity and material at the tooth level. Associations were tested using multilevel logistic regression models. RESULTS: A total of 1,000 participants and 249 restorations in the permanent dentition were examined. Most of the restorations were composites (73.5%), while only 6.8% were amalgam. After adjusted analyses, children whose parents received information on how to prevent their child from developing caries before reaching 5 years of age had 91.0% less chance of having an unsatisfactory restoration compared to children whose parents never received information (OR = 0.09; 95% CI 0.01-0.59). Also, the chances of presenting unsatisfactory restorations were 5.3 higher in children at high-risk for untreated dental caries in the permanent dentition, in comparison with children at low risk (OR = 5.32; 95% CI 1.07-26.6). CONCLUSIONS: Low-risk for untreated dental caries and having received information on preventing dental caries, reduced the chance of presenting failed restorations, showing that factors related to individuals play an important role in the quality of restorations. CLINICAL SIGNIFICANCE: Our findings highlight the role that individual-related factors play in restoration longevity in children, reinforcing the need for a patient-centered approach in restorative dentistry.

Maternal depression symptoms and use of child health-care services at The Pelotas 2004 Birth Cohort.

OBJECTIVE: To investigate the influence of maternal depression on child health-care services utilization. METHODOLOGY: Data from The Pelotas 2004 Birth Cohort collected at birth and at 12- and 24-month follow-ups were used. Four outcomes occurring in the second year of life were investigated: number of well-baby visits, number of medical appointments, number of visits to emergency rooms, and number of hospitalizations. The main exposure was maternal depression symptoms at 12-month post-partum as assessed by the Edinburgh Postpartum Depression Scale (EPDS). Adjusted prevalence ratios (PR) with 95% confidence intervals (95% CI) were calculated by Poisson regression. RESULTS: The prevalence of mothers with depressive symptoms was 27.6% (95% CI: 26.2-29.0%). These mothers showed a 10% lower probability of taking their children to well-baby visits (0.90; 0.85-0.95; p = 0.001); 16% higher probability to seek medical consultations (1.16; 1.09-1.25, p = 0.001); and they sought emergency services for their children more often (1.30; 1.17-1.45, p < 0.001) as compared to mothers who did not present depressive symptoms. Although the PR for hospitalizations was 26% higher for children from mothers with depressive symptoms, the association did not achieve statistical significance (1.26; 0.98-1.63; p = 0.072). CONCLUSION: Children from mothers with depressive symptoms attend fewer number of preventive consultations. In contrast, they are taken to medical and emergency care more often, suggesting that these children are given healthcare when they are at more advanced stages of their illnesses.

Maternal depression is associated with injuries in children aged 2-4 years: the Pelotas 2004 Birth Cohort.

INTRODUCTION: Injuries during childhood, which mostly consist of falls, burns, drowning, poisonings and car crashes, are among the main causes of death among children and young adults in several countries. OBJECTIVES: To investigate the association between maternal depression and the incidence of injuries during childhood. METHODS: In 2004, children who were born in the municipality of Pelotas, Brazil, were enrolled in a population-based birth cohort, with evaluations at birth and at 3, 12, 24 and 48 months of age. Maternal depression during pregnancy was evaluated at the time of delivery. At 12 and 24 months post partum, the Edinburgh Postnatal Depression Scale (EPDS) was used. The injuries incidence rates at ages of 24-48 months and the crude and adjusted IRRs were calculated with 95% CI through Poisson's regression. RESULTS: A total of 3533 children were analysed. The incidence of injuries was higher among children whose mothers presented depressive symptoms during pregnancy and at 12 and 24 months compared with those whose mothers did not present any symptoms. In the adjusted analysis, the IRR among girls whose mothers presented depressive symptoms during pregnancy and EPDS ≥13 at 12 and 24 months was 1.31 (1.15-1.50); and, among boys, 1.18 (1.03-1.36). INTERPRETATION: Maternal depression is associated with higher incidence of injuries between 24 and 48 months of age, in both sexes.

Epidemiology of Acne Vulgaris in 18-Year-Old Male Army Conscripts in a South Brazilian City.

BACKGROUND: Prevalence of acne varies worldwide. Several factors (age, skin color, body fat, diet, and smoking) have been investigated as risk factors. OBJECTIVE: A total of 2,201 18-year-old males living in Pelotas, South Brazil, were evaluated in order to examine the prevalence of acne and associated factors. METHODS: A cross-sectional population-based study was conducted. A dermatologist performed the clinical examination of the face and trunk for identification of acne lesions. Acne was evaluated as clinically noninflammatory, inflammatory, and acne with both types of lesions. Skin color, schooling, height, smoking, skinfolds, waist circumference, BMI, and dietary dairy intake were the independent variables used. RESULTS: A response rate of 97.2% was obtained. Individuals without any acne lesion were 241 (10.9%); 161 (7.3%) only had noninflammatory lesions, 404 (18.4%) only inflammatory lesions; and 1,395 (63.4%) presented both types of lesions. In multivariate analysis, the type of lesions was different in light and dark skin phototype adolescents, with more common inflammatory lesions in the light phototype and noninflammatory ones in the dark phototype patients. Height was directly associated with the occurrence of all types of acne, whereas lower fat mass was associated with the occurrence of noninflammatory acne. While daily consumption of whole milk or yogurt was found to be associated with inflammatory acne in crude analysis, the association with milk was not detected and that with yogurt was low in multivariate analysis. CONCLUSION: Our results suggest that future studies should explore determinants of noninflammatory and inflammatory acne separately, especially if mixed populations are studied.

Intellectual Disability in a Birth Cohort: Prevalence, Etiology, and Determinants at the Age of 4 Years.

BACKGROUND: Intellectual disability (ID), characterized by impairments in intellectual function and adaptive behavior, affects 1-3% of the population. Many studies investigated its etiology, but few are cohort studies in middle-income countries. AIMS: To estimate prevalence, etiology, and factors related to ID among children prospectively followed since birth in a Southern Brazilian city (Pelotas). METHODS: In 2004, maternity hospitals were visited daily and births were identified. Live-born infants (n = 4,231) whose family lived in the urban area have been followed for several years. At the age of 2 and 4 years, performances in development and intelligence tests were evaluated using the Battelle Developmental Inventory and Wechsler Intelligence Scale, respectively. Children considered as having developmental delay were invited to attend a genetic evaluation. RESULTS: At 4 years of age, the prevalence of ID was 4.5%, and the etiology was classified into 5 groups: environmental (44.4%), genetic (20.5%), idiopathic (12.6%), neonatal sequelae (13.2%), other diseases (9.3%). Most children presented impairment in two or more areas of adaptive behavior. There was no difference in prenatal care attendance or maternal schooling among the groups. CONCLUSION: For about 40% of children, ID was attributed to nonbiological factors, suggesting that the rate may be reduced with appropriate interventions early in life.

[Diet quality of preschool children aged 2 to 5 years living in the urban area of Pelotas, Brazil]. / Qualidade da dieta de pré-escolares de 2 a 5 anos residentes na área urbana da cidade de Pelotas, RS.

OBJECTIVE: To assess the dietary quality of preschool children in the urban area of Pelotas, Rio Grande do Sul, southern Brazil. METHODS: Dietary quality was measured according to the Healthy Eating Index (HEI), adapted to Brazil. Food consumption was obtained using the Food Frequency Questionnaire (FFQ). The index score was obtained by a score, ranging from 0 to 100, distributed in 13 food groups that characterize different components of a healthy diet. The better the quality of the diet, the closer the score is to 100. RESULTS: Dietary was evaluated in 556 preschoolers. The mean HEI score value was 74.4 points, indicating that diets need improvement. The mean scores were significantly higher among girls and in children from families with income between one and less than three minimum wages. CONCLUSIONS: The children showed vegetable consumption below the recommended level, while the food group of oils and fats, as well as the group of sugars, candies, chocolates and snacks were consumed in excess. It is important to reinforce guidelines to promote healthier eating habits, which may persist later in life.

Oral mucosal lesions' impact on oral health-related quality of life in preschool children.

OBJECTIVES: The aim of this study was to assess the prevalence of oral mucosal lesions and their impact on oral health-related quality of life (OHRQoL) in children aged 5 years. METHODS: A sample of 1118 children from Pelotas' birth cohort, born in 2004 (response rate of 85.8%), were selected to participate in the study. Data were collected using a questionnaire applied to mothers and from the oral examinations of the children. OML were identified by type, site, and size. Early Childhood Oral Health Impact Scale (ECOHIS) was used to assess caregivers' perception on children's OHRQoL. Descriptive, bivariate, and multivariate Poisson regression analyses were carried out, considering the impact on OHRQoL (total ECOHIS score) as the outcome. RESULTS: The prevalence of the OML was 30.1% (95% CI 27.5-32.9). Ulcers were the more prevalent type of lesion (29.4%), and the most affected site was the gums (31.0%). In bivariate analysis, there was a positive association between the presence of OML and OHRQoL impact measured by the following: mean overall score of ECOHIS (P < 0.001); extent (P < 0.001); prevalence (P = 0.030); and intensity (P = 0.010). After adjustments for sociodemographic and oral health variables, children with OML presented higher impact on OHRQoL [rate ratio (RR) 1.38 95% CI 1.11; 1.72] comparing with their counterparts. Analyzing specific domains, children with OML also presented higher impact on children symptoms (RR 1.46 95% CI 1.20; 1.66) and family functional (RR 3.14 95% CI 1.59; 6.22) domains. CONCLUSION: Almost one-third of children presented with oral mucosal lesions, and these lesions impaired children's oral health-related quality of life.

Knowledge and beliefs concerning early childhood caries from mothers of children ages zero to 12 months.

PURPOSE: This study's purpose was to assess mothers' knowledge and beliefs about early childhood caries (ECC) etiology and prevention. METHODS: This cross-sectional study targeted mothers (N=277) of zero- to 12-month-olds visiting 12 public health care centers in Pelotas, Rio Grande do Sul, Brazil. Information on causes of and recommendations to prevent ECC, as well as socioeconomic and demographic variables, was collected. Chi-square, univariate, and multiple logistic regression analyses were performed (P<.05). RESULTS: Sugar intake and lack of oral hygiene were the most frequently mentioned causes of caries. Ninety percent of the mothers were aware of the need to begin tooth-brushing during their children's first year. Mothers who had more children and were in lower socioeconomic positions were more likely to not know the correct age for the first dental visit. CONCLUSIONS: Our findings showed that mothers do not know all the factors that can influence caries in their children. None reported the role of micro-organisms and lack of fluoride in the caries etiology. These findings highlight the importance of providing preventive orientation to the mothers regarding early childhood caries. Information on age of first dental visit should be emphasized, especially among mothers with more than one child and low-income families.

Accuracy and adequacy of waist circumference cut-off points currently recommended in Brazilian adults.

OBJECTIVE: To evaluate the adequacy and accuracy of cut-off values currently recommended by the WHO for assessment of cardiovascular risk in southern Brazil. DESIGN: Population-based study aimed at determining the predictive ability of waist circumference for cardiovascular risk based on the use of previous medical diagnosis for hypertension, diabetes mellitus and/or dyslipidaemia. Descriptive analysis was used for the adequacy of current cut-off values of waist circumference, receiver operating characteristic curves were constructed and the most accurate criteria according to the Youden index and points of optimal sensitivity and specificity were identified. SETTING: Pelotas, southern Brazil. SUBJECTS: Individuals (n 2112) aged ≥20 years living in the city were selected by multistage sampling, since these individuals did not report the presence of previous myocardial infarction, angina pectoris or stroke. RESULTS: The cut-off values currently recommended by WHO were more appropriate in men than women, with overestimation of cardiovascular risk in women. The area under the receiver operating characteristic curve showed moderate predictive ability of waist circumference in men (0.74, 95% CI 0.71, 0.76) and women (0.75, 95% CI 0.73, 0.77). The method of optimal sensitivity and specificity showed better performance in assessing the accuracy, identifying the values of 95 cm in men and 87 cm in women as the best cut-off values of waist circumference to assess cardiovascular risk. CONCLUSIONS: The cut-off values currently recommended for waist circumference are not suitable for women. Longitudinal studies should be conducted to evaluate the consistency of the findings.

Knowledge and Beliefs Concerning Early Childhood Caries From Mothers of Children Ages Zero to 12 Months.

PURPOSE: This study's purpose was to assess mothers' knowledge and beliefs about early childhood caries (ECC) etiology and prevention. METHODS: This cross-sectional study targeted mothers (N=277) of zero- to 12-month-olds visiting 12 public health care centers in Pelotas, Rio Grande do Sul, Brazil. Information on causes of and recommendations to prevent ECC, as well as socioeconomic and demographic variables, was collected. Chi-square, univariate, and multiple logistic regression analyses were performed (P<.05). RESULTS: Sugar intake and lack of oral hygiene were the most frequently mentioned causes of caries. Ninety percent of the mothers were aware of the need to begin tooth-brushing during their children's first year. Mothers who had more children and were in lower socioeconomic positions were more likely to not know the correct age for the first dental visit. CONCLUSIONS: Our findings showed that mothers do not know all the factors that can influence caries in their children. None reported the role of micro-organisms and lack of fluoride in the caries etiology. These findings highlight the importance of providing preventive orientation to the mothers regarding early childhood caries. Information on age of first dental visit should be emphasized, especially among mothers with more than one child and low-income families.

Gestational age at birth and morbidity, mortality, and growth in the first 4 years of life: findings from three birth cohorts in Southern Brazil.

BACKGROUND: We assessed anthropometric status, breastfeeding duration, morbidity, and mortality outcomes during the first four years of life according to gestational age, in three population-based birth cohorts in the city of Pelotas, Southern Brazil. METHODS: Total breastfeeding duration, neonatal mortality, infant morbidity and mortality, and anthropometric measures taken at 12 and 48 months were evaluated in children of different gestational ages born in 1982, 1993 and 2004 in Southern Brazil. RESULTS: Babies born <34 weeks of gestation and those born between 34-36 weeks presented increased morbidity and mortality, were breastfed for shorter periods, and were more likely to be undernourished at 12 months of life, in comparison with the 39-41 weeks group. Children born with 37 weeks were more than twice as likely to die in the first year of life, and were also at increased risk of hospitalization and underweight at 12 months of life. Post-term infants presented an increased risk of neonatal mortality. CONCLUSION: The increased risks of morbidity and mortality among preterm (<37 weeks of gestation) and post-term (>41 weeks) are well known. In our population babies born at 37 also present increased risk. As the proportion of preterm and early term babies has increased markedly in recent years, this is a cause for great concern.

Non classical risk factors for gestational diabetes mellitus: a systematic review of the literature.

Age, obesity and family history of diabetes are well known risk factors for gestational diabetes mellitus. Others are more controversial. The objective of this review is to find evidence in the literature that justifies the inclusion of these other conditions among risk factors. The MEDLINE, Cochrane, LILACS and Pan American Health Organization databases were searched, covering articles dating from between 1992 and 2006. Keywords were used in combination (AND) with gestational diabetes mellitus separately and with each one of the risk factors studied. The methodological quality of the studies included was assessed, resulting in the selection of 41 papers. Most studies investigating maternal history of low birth weight, low stature, and low level of physical activity have found positive associations with gestational diabetes mellitus. Low socioeconomic levels, smoking during pregnancy, high parity, belonging to minority groups, and excessive weight gain during pregnancy presented conflicting results. Publication bias cannot be ruled out. Standardization of techniques, cutoff points for screening and diagnosis, as well as studies involving larger sample sizes would allow future meta-analyses.

A double-blind randomized controlled clinical trial of 10 percent versus 16 percent carbamide peroxide tooth-bleaching agents: one-year follow-up.

BACKGROUND: The use of high-concentration tooth-bleaching agents has been associated with increased longevity of the whitening effect. The authors conducted a randomized controlled clinical trial to evaluate the longevity of the whitening effect at one year of two at-home tooth-bleaching agents. METHODS: The authors randomly assigned 92 participants with a mean shade of C1 or darker for six maxillary anterior teeth into two equal-sized groups according to carbamide peroxide concentration: 10 percent (CP10) or 16 percent (CP16). Treatment involved the use of a whitening agent in a tray for two hours daily for three weeks. The authors evaluated tooth shade with a shade guide and a spectrophotometer at baseline and one week, six months and one year after bleaching. Participants in both groups answered questions about their dietary and oral hygiene behaviors. RESULTS: At the one-year recall appointment, the teeth in both groups remained significantly lighter than at baseline. At this time, participants from the CP10 and CP16 groups consumed staining beverages and foods at a level as high as at the six-month recall appointment, and this consumption level was not statistically significant between groups (P > .5). CONCLUSIONS: One year after bleaching, both treatment groups had the same median tooth shade, which remained lighter than at baseline. CLINICAL IMPLICATIONS: Higher carbamide peroxide concentration does not increase the longevity of the whitening effect of at-home tooth-bleaching agents.