Biomedical subjects

G Verbeke

Publications and source records attributed to G Verbeke.

At least 19 recordsLinked to original sources

PubMed1999

Assessing the goodness-of-fit of the Laird and Ware model--an example: the Jimma Infant Survival Differential Longitudinal Study.

The Jimma Infant Survival Differential Longitudinal Study is an Ethiopian study, set up to establish risk factors affecting infant survival and to investigate socio-economic, maternal and infant-rearing factors that contribute most to the child's early survival. Here, a subgroup of about 1500 children born in Jimma town is examined for their first year's weight gain. Of special interest is the impact of certain cultural practices like uvulectomy, milk teeth extraction and butter swallowing, on child's weight gain; these have never been thoroughly investigated in any study. In this context, the linear mixed model (Laird and Ware) is employed. The purpose of this paper is to illustrate the practical issues when constructing the longitudinal model. Recently developed diagnostics will be used herefor. Finally, special attention will be paid to the two-stage interpretation of the linear mixed model.

Adult↗

PubMed1999

Variceal pressure is a strong predictor of variceal haemorrhage in patients with cirrhosis as well as in patients with non-cirrhotic portal hypertension.

BACKGROUND: Variceal pressure is a strong predictor for a first variceal bleed in patients with cirrhosis. AIMS: To evaluate whether variceal pressure is also a determinant of the risk of a first variceal bleed in patients with non-cirrhotic portal hypertension. METHODS: Variceal pressure was measured non-invasively in 25 patients with non-cirrhotic portal hypertension and large varices while receiving a stable therapeutic regimen. Factors predictive of bleeding were compared with those observed in 87 cirrhotics. RESULTS: The one year incidence of variceal bleeding was 32% (n=28) for the cirrhotic and 20% (n=5) for the non-cirrhotic patients. There was no difference in factors predicting the risk of bleeding between the groups, except for variceal pressure. For the same level of variceal pressure, the risk of variceal bleeding was lower in patients with non-cirrhotic portal hypertension. Multiple logistic regression analysis revealed the following variables as having a significant predictive power: variceal pressure (p=0.0001), red spots (p=0.004), and the time interval between the first observation of the varices and the moment of variceal pressure measurement (p=0. 0046). For the non-cirrhotics the risk of bleeding increased with higher Child-Pugh score (p=0.0024); this was not the case for the cirrhotic patients (p=0.9521). CONCLUSION: Variceal pressure is a major predictor of variceal bleeding in patients with cirrhosis as well as in patients with non-cirrhotic portal hypertension. The risk of bleeding in non-cirrhotics is less than in cirrhotics for the same level of variceal pressure. In patients with non-cirrhotic portal hypertension the risk of variceal bleeding increases more with advancing disease.

Adult↗

PubMed1999

Down-regulation of the serum stimulatory components of the insulin-like growth factor (IGF) system (IGF-I, IGF-II, IGF binding protein [BP]-3, and IGFBP-5) in age-related (type II) femoral neck osteoporosis.

Both a decrease in bone formation and an increase in bone resorption have been implicated in the pathogenesis of age-related (type II) femoral neck osteoporosis. While the increase in the bone resorption rate has been shown to be partially related to secondary hyperparathyroidism, the mechanisms underlying the decline in bone formation have not yet been identified. The aim of the present study was to test the hypothesis that the bone formation deficit associated with type II osteoporosis might be due to secondary hyperparathyroidism and/or to a deficiency of the insulin-like growth factor (IGF) system. Circulating concentrations of IGF-I, IGF-II, IGF binding protein (IGFBP)-3, IGFBP-4, IGFBP-5, 25-hydroxycholecalciferol (25(OH)D3), and intact parathyroid hormone (PTH) were measured in 50 elderly women after sustaining a hip fracture and in 50 healthy age-matched controls. In addition, serum levels of osteocalcin (OC), skeletal alkaline phosphatase, and N-terminal procollagen peptide and urinary pyridinium cross-links were determined as markers of bone remodeling, and bone mineral density (BMD) was assessed at the proximal femur. In the patient group, serum was drawn within 18 h of the fracture and prior to surgery. Circulating protein concentrations did not change over this time frame. No difference was found between mean IGFBP-4 serum levels in the two groups studied, while mean levels of IGF-I, IGF-II, IGFBP-3, IGFBP-5, 25(OH)D3, and markers of bone formation were significantly lower (p < 0.006) in patients as compared with healthy subjects. Serum PTH and urinary pyridinium cross-links, however, were markedly increased (p < 0.001) in the osteoporotic group. In pooled data from the normal and osteoporotic populations, age-adjusted multiple regression models based on IGF-I, IGF-II, IGFBP-3, and IGFBP-5 were found to be highly predictive of serum OC (R2 = 19%, p < 0.001) and BMD of femoral neck (R2 = 49%, p < 0.0001), consistent with an effect of the anabolic IGF components on overall bone formation rate. Similar models based on 25(OH)D3 and PTH, however, were statistically unrelated to OC. To address further the potential impact of trauma on circulating IGF system components, we measured IGF system component levels in 10 male patients within 18 h following tibial fracture and in 10 age-matched normal male subjects. There was no significant difference in serum level of any of the IGF system components between the two groups. Although limited by its cross-sectional design, the present study suggests that, in addition to bone resorption resulting from secondary hyperparathyroidism, impaired bone formation associated with deficiency of the IGF system might predispose elderly women to fragility fracture of the proximal femur.

Age Factors↗

PubMed1998

The detection of residual serial correlation in linear mixed models.

Diggle (1988) described how the empirical semi-variogram of ordinary least squares residuals can be used to suggest an appropriate serial correlation structure in stationary linear mixed models. In this paper, this approach is extended to non-stationary models which include random effects other than intercepts, and will be applied to prostate cancer data, taken from the Baltimore Longitudinal Study of Aging. A simulation study demonstrates the effectiveness of this extended variogram for improving the covariance structure of the linear mixed model used to describe the prostate data.

Analysis of Variance↗

PubMed1998

Comparative effects of neonatal and prepubertal castration on craniofacial growth in rats.

The role of endogenous testosterone in the craniofacial growth of the young male rat was investigated. First, the effect of neonatal surgical castration was examined in a randomized, cross-sectional study in which male Wistar rats were allocated to be either castrated or sham-operated 4 h after birth. Then, the effect of prepubertal chemical castration was analysed in a second, randomized longitudinal study in which male Wistar rats were randomly allocated either to a control group or to two experimental groups, one injected with triptorelin at day 25 and the other injected on day 25 and on day 45. Every tenth day between 20 and 70 days of age for the first study, and between 30 and 110 days of age for the second, body length and weight were measured, cephalometric X-rays taken, and blood samples obtained. Neonatal and prepubertal castration resulted in decreased plasma concentrations of testosterone and in delayed growth of somatic and craniofacial components. The initiation, duration and magnitude of the effect was dependent on individual bones (cranial base, skull roof) and on the lower incisor, and related to the testosterone concentrations. These results suggest that testosterone effects participate in the process of normal craniofacial growth, particularly during puberty.

Aging↗

PubMed1998

Relationship between age-associated endocrine deficiencies and muscle function in elderly women: a cross-sectional study.

OBJECTIVE: Muscle receptors and selected anabolic effects have been identified for both insulin-like growth factor I (IGF-I) and 1,25-dihydroxyvitamin D (1,25(OH)2D3). The aim of the present study was to test the hypothesis that the decreasing concentrations of these endocrine factors might be involved in the decline in muscle function that characterizes normal human ageing. DESIGN: Cross-sectional study. STUDY PARTICIPANTS: A community-based sample of 245 healthy elderly women aged 70-90 years. Exclusion criteria were diseases or medications known to affect muscle function or the somatotrophic axis. MEASUREMENTS: Knee extension strength was evaluated using an isokinetic dynamometer. A standardized questionnaire was used to assess habitual physical activity. IGF-I and 1,25(OH)2D3 were measured by radioimmunoassay. Vitamin D binding protein (DBP) was measured by single radial immunodiffusion and the free 1,25(OH)2D3 concentration calculated as the molar ratio of total 1,25(OH)2D3 to DBP. RESULTS: The differences in isometric and isokinetic strength over the age range were equivalent to losses of 0.9-2.4% per year. However, no relationship was found between the somatotrophic axis or vitamin D status and knee extension strength, despite markedly decreasing concentrations of circulating IGF-I and free 1,25(OH)2D3 with age. CONCLUSION: Levels of circulating IGF-I and free 1,25(OH)2D3 appear not to be involved in the loss of muscle function that characterizes normal human ageing.

Aged↗

PubMed1998

Local influence in linear mixed models.

The linear mixed model has become an important tool in modelling, partially due to the introduction of the SAS procedure MIXED, which made the method widely available to practising statisticians. Its growing popularity calls for data-analytic methods to check the underlying assumptions and robustness. Here, the problem of detecting influential subjects in the context of longitudinal data is considered, following the approach of local influence proposed by Cook.

Age Factors↗

PubMed1997

Factors associated with cortical and trabecular bone loss as quantified by peripheral computed tomography (pQCT) at the ultradistal radius in aging women.

Peripheral quantitative computed tomography (pQCT) allows the separate determination of cortical and trabecular bone mineral density in the peripheral skeleton. This cross-sectional study was designed to examine the effects of healthy aging on pQCT measurements at the ultradistal radius. In a well-defined sample of 129 community-based women, aged 70-87 years, the differences in cortical and trabecular density over the age range were equivalent to losses of -0.41% and -0.65% per year, respectively. To investigate the mechanism of this age-related decline, we assessed relationships between both parameters and height, weight, body mass index, dietary calcium intake, grip strength, and serum concentrations of insulin-like growth factor-I (IGF-I), calcidiol (25(OH)D3), calcitriol (1,25(OH)2D3), parathyroid hormone (PTH), and sex hormone binding globulin (SHBG). Multiple regression was used to adjust for potential confounders. Age was not significant after controlling for other covariables. Body mass index, grip strength, serum IGF-I, 25(OH)D3, and PTH (1-84) were found to be independent predictors of total bone density. Including (total or free) 1,25(OH)2D3 did not improve the model precision. These findings provide evidence that, among other factors, the activity of the growth hormone-IGF-I-axis is of importance for skeletal integrity. Grip strength, serum IGF-I, and PTH (1-84) were discovered to be significantly related to cortical but not to trabecular density, suggesting that different mechanisms may be involved in compact and cancellous bone loss.

Aged↗

PubMed1997

Age-associated decline in human femoral neck cortical and trabecular content of insulin-like growth factor I: potential implications for age-related (type II) osteoporotic fracture occurrence.

Recent evidence suggests that regulatory peptides such as insulin-like growth factor-I (IGF-I) are released locally from bone during resorption, and may then act in a sequential manner to regulate the cellular events required for the coupling of bone formation to resorption. Among other factors, a decrease in bone-associated IGF-I levels could therefore result in remodeling imbalance and contribute to the gradual loss of bone that occurs with age. As the femoral neck region is of primary concern for the clinical manifestations of osteoporosis, the current study was intended to assess the IGF-I contents in femoral neck cortical and trabecular bone from aging individuals. Bone samples from the neck region were obtained at postmortem from 39 females and 35 males, aged 23-92 years. Concentrations of IGF-I and osteocalcin were measured by radioimmunoassay in the supernatants obtained after EDTA and guanidine hydrochloride extraction. The total amount of protein present in the extracts was determined by spectrophotometry. IGF-I levels were significantly lower in trabecular compared with cortical bone. Though femoral neck total protein did not vary with donor age, both IGF-I and osteocalcin were found to decline markedly. Between the ages of 23 and 92 years, average yearly rates of loss of 0.30 and 0.21 ng IGF-I/mg protein were observed in cortical and trabecular bone, respectively, corresponding with net losses of nearly 35% of the cortical skeletal content of IGF-I and 41% of the trabecular skeletal content of IGF-I. These changes in bone-associated IGF-I paralleled those of osteocalcin, consistent with an overall decrease in osteoblast function with aging. In women, the rate of decline was significantly faster for trabecular than for cortical IGF-I, however in men, age-dependent changes in cortical and trabecular IGF-I were similar. These findings support the hypothesis that changes in the local IGF regulatory system over time could be a pathophysiologic component of the age-related (type II) femoral neck osteoporotic syndrome.

Adult↗

PubMed1997

Clustering of increased small intestinal permeability in families with Crohn's disease.

BACKGROUND & AIMS: Small intestinal permeability is increased in a proportion of patients with Crohn's disease (CD) and a subset of their healthy relatives. A primary permeability defect was postulated in the pathogenesis of the disease. The aim of this study was to identify a possible genetic pattern in the distribution of CD and/or abnormal permeability. METHODS: Differential urinary excretion of lactulose and mannitol (L/ M) in complete CD families was determined. Controls included healthy families and families with ulcerative colitis. Pedigrees were used to compare the distribution of CD and/or increased permeability. RESULTS: The L/M was significantly increased in patients with CD. Seventeen of 67 first-degree relatives (25%) had a ratio greater than the upper limit (P95 = 0.0170). Permeability results of CD families showed a highly significant familial aggregation. The lack of a genetic pattern in relation with CD and occurrence of disturbed permeability especially within generation, points toward a shared environmental factor. Five of 14 healthy spouses (36%) of patients with CD had also an increased permeability, and prevalence of increased permeability was not higher in families with known familial occurrence (P = 0.85). CONCLUSIONS: This large family study confirms an increased permeability in a subset of healthy relatives of patients with CD. However, the absence of a typical family pattern and the high prevalence in spouses is in favor of a common nongenetic factor or a subclinical disease manifestation.

Adolescent↗

PubMed1997

The accuracy of peripheral skeletal assessment at the radius in estimating femoral bone density as measured by dual-energy X-ray absorptiometry: a comparative study of single-photon absorptiometry and computed tomography.

OBJECTIVES: One of the latest developments in bone densitometry is peripheral quantitative computed tomography (pQCT), a method which allows the separate determination of cortical and trabecular bone mineral density (BMD) in the peripheral skeleton. This study was designed to compare the relative abilities of single-photon absorptiometry (SPA) and pQCT to reflect BMD of the proximal femur as measured by dual-energy X-ray absorptiometry (DXA), an established predictor of osteoporotic hip fracture risk. DESIGN: Cross-sectional study. SUBJECTS: A well-defined community-based sample of 129 skeletally healthy women aged 70-87 years. MEASUREMENTS: Radial BMD by SPA and pQCT and femoral BMD by DXA. Univariate and multivariate regression analyses were performed relating the DXA measurements at the femoral neck and the trochanteric region with the values of SPA and pQCT. RESULTS: Approximately 38% of the variance in femoral neck BMD could be explained by BMD of the midradius assessed by SPA, in contrast to only 18-27% by pQCT. At the trochanter, 32% of BMD could be predicted by SPA as compared to 19-26% by pQCT. Moreover, according to multiple regression, prediction of femoral BMD by SPA was not enhanced by performing pQCT. CONCLUSIONS: Radial pQCT has little value as a screening tool to identify elderly women with low femoral BMD. Additional research is needed to determine whether or not pQCT will enhance fracture prediction beyond that obtainable from a density measurement by SPA.

Absorptiometry, Photon↗

PubMed1997

Determinants of age-associated changes in os calcis ultrasonic indices in elderly women: potential involvement of geriatric hyposomatotropism in bone fragility.

OBJECTIVE: ultrasound measures a clinically relevant property of bone strength in addition to and distinct from bone mass. The aim of the present study was to examine the effects of healthy ageing on ultrasound measurements of the calcaneus. DESIGN: cross-sectional study. STUDY PARTICIPANTS: a sample of 177 community-dwelling healthy women aged 70-87 years. Exclusion criteria were diseases or medications known to affect the musculoskeletal system or the somatotrophic axis. MEASUREMENTS: serum levels of 1,25-dihydroxyvitamin D3 and insulin-like growth factor-I (IGF-I) were measured by radioimmunoassay, serum 25-hydroxyvitamin D3 (25(OH)D3) was determined by competitive binding assay and serum parathyroid hormone was assessed immunochemically. Isometric and isokinetic quadriceps strength were evaluated using a Cybex II system. Calcaneal ultrasound indices--broadband ultrasound attenuation (BUA) and speed of sound (SOS)--were measured with an Achilles system. RESULTS: we found a significant decrease with ageing in BUA and SOS (-0.5 and -1.3% per year, respectively), suggesting a continuing loss of bone quality. Quadriceps strength, serum IGF-I and 25(OH)D3 constituted the best predictors of BUA, while IGF-I was the only parameter found to be independently associated with SOS. CONCLUSION: these findings suggest that, among other factors, the activity of the growth hormone-IGF-I axis is of importance for skeletal integrity. Age-related bone fragility may, in part, be related to geriatric hyposomatotropism.

Aged↗

PubMed1997

Calciotropic hormones and markers of bone remodeling in age-related (type II) femoral neck osteoporosis: alterations consistent with secondary hyperparathyroidism-induced bone resorption.

BACKGROUND: Both a decrease in bone formation and the skeletal consequences of secondary hyperparathyroidism have been implied in the pathogenesis of age-related femoral neck osteoporosis. However, studies using biochemical indices of bone remodeling in hip fracture patients have yielded conflicting results. Similarly, secondary hyperparathyroidism has not been a consistent finding in this population. Some of these inconsistencies might reflect differences in the assays used as well as in the timing of the sampling. Moreover, measurements were mostly performed in a limited number of patients. In this regard, the aim of the present study was to analyze potential alterations in bone metabolism in a large population of elderly hip fracture patients. METHODS: Circulating concentrations of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)2D3], intact parathyroid hormone (PTH), and calcitonin were measured in 117 elderly women (within a few hours after sustaining a fracture of the proximal femur) and in 117 healthy age-matched controls. In addition, serum osteocalcin and urinary excretion of (deoxy)pyridinoline were determined as markers of bone formation and resorption, respectively. RESULTS: Serum levels of 25(OH)D and 1,25(OH)2D3 were decreased in hip fracture patients. When correcting for differences in serum vitamin D binding protein, serum 25(OH)D was still significantly lower in patients than in controls, whereas serum 1,25(OH)2D3 was not. Moreover, 25(OH)D deficiency in hip fracture patients was associated with an increase in circulating PTH and urinary excretion of (deoxy)pyridinoline. Serum osteocalcin, on the other hand, was significantly decreased in fracture patients. There was no statistically significant difference in calcitonin. CONCLUSION: These data suggest that there is reduced bone formation and increased bone resorption in patients with hip fracture. Although limited by its cross-sectional design, the present study emphasizes the role of secondary hyperparathyroidism-induced bone resorption in the pathogenesis of age-related osteoporosis, mainly due to a lack of 25(OH)D.

Aged↗

PubMed1997

Craniofacial growth in short children born small for gestational age: effect of growth hormone treatment.

The effects of growth hormone (GH) therapy in children have yet to be completely catalogued. In the present study, the effect of high-dose GH treatment on craniofacial growth was evaluated once yearly in 21 pre-pubertal, non-GH-deficient children born small for gestational age. These children were randomly allocated to be either untreated or treated with GH at a daily subcutaneous dose of 0.2 or 0.3 IU/kg for 2 yrs. The group consisted of 12 girls and 9 boys with a mean age of 5.1 yr (range, 2 to 8 yr), bone age of 3.4 yr, and height SDS of -3.6. At the start of the study, all children showed an overall delay of craniofacial growth. This cohort of short children born small for gestational age showed a small SNB angle and a large ANB angle; all other angular measurements were within normal range. GH treatment accelerated growth in several craniofacial components, especially the posterior total facial height, the cranial base length, and the overall mandibular length. The increase of the mandibular length increased the SNB angle; no other angular measurements were affected. Age at start of treatment differently influenced the increase in posterior and total cranial base length, the increase in mandibular corpus length, and the position of the mandible in relation to the cranial base. Although GH treatment for 2 yrs led to a craniofacial growth acceleration, the position of the mandible in relation to the cranial base and the craniofacial size in lateral aspect were not normalized in the majority of the GH-treated children. No signs of disproportional growth were evidenced after 2 yrs of high-dose GH treatment. In conclusion, short pre-pubertal SGA children display an overall delay of linear craniofacial growth and a retrognathic mandible. High-dose GH treatment over 2 yrs leads to craniofacial catch-up growth, which is pronounced in regions where interstitial cartilage is involved and results in a less convex face in profile.

Age Determination by Skeleton↗

PubMed1997

Age-related (type II) femoral neck osteoporosis in men: biochemical evidence for both hypovitaminosis D- and androgen deficiency-induced bone resorption.

The problem of osteoporosis in men has recently been recognized as an important public health issue. To test the hypothesis that endocrine deficiency-mediated alterations in bone metabolism might contribute to osteoporotic fracture risk in elderly men, serum levels of 25-hydroxycholecalciferol (25(OH)D), 1,25-dihydroxycholecalciferol (1,25(OH)2D), intact parathyroid hormone (PTH), testosterone, and estradiol were measured in 40 males (mean age 73 years) who were consecutively recruited within 18 h following a fracture of the proximal femur, and in an equal number of community-living older men (mean age 72 years) who served as controls. In addition, circulating osteocalcin and urinary excretion of (deoxy)pyridinoline were determined as markers of bone formation and resorption, respectively. No differences were observed between the mean serum concentrations of osteocalcin and estradiol. Serum levels of 25(OH)D, 1,25(OH)2D, and testosterone, however, were decreased in hip fracture patients. When correcting for differences in vitamin D binding protein, differences in 1,25(OH)2D did not persist, whereas serum 25(OH)D was still significantly lower in patients than in controls (6.1 +/- 4.3 vs. 7.6 +/- 2.8, p = 0.01). Similarly, a highly significant deficit was observed in the free testosterone index, calculated from total testosterone and the level of sex hormone binding globulin (2.6 +/- 1.3 vs. 8.2 +/- 2.9, p < 0.001). Serum PTH and urinary pyridinium cross-links, however, were markedly increased in the fracture group. Moreover, in fracture patients, free 25(OH)D and free testosterone were both significant and mutually independent negative predictors of (deoxy)pyridinoline excretion. Although limited by its cross-sectional design, the present study suggests that both hypovitaminosis D and androgen deficiency may predispose to bone resorption in elderly men and in turn to remodeling imbalance and fracture risk.

Aged↗

PubMed1997

A patient with unique bilateral ovarian metastases 11 years after the treatment of breast cancer.

We report a patient in whom 11 years after the treatment of a breast tumour, bilateral ovarian metastases were disclosed. Surgical exploration confirmed unique ovarian metastases within a 'clean' abdomen and pelvis. The particularities of this case compared with the literature are the rather long interval of 11 years and the fact that no other metastases were present. The literature indeed reveals that most of the patient with ovarian metastases are premenopausal, have bilateral involvement; the ovarian metastases occur within a few years and are frequently accompanied by other metastases.

Breast Neoplasms↗

PubMed1995

Measurement of femoral geometry in type I and type II osteoporosis: differences in hip axis length consistent with heterogeneity in the pathogenesis of osteoporotic fractures.

The epidemiologic patterns of vertebral and femoral fractures are sufficiently different to suggest that they represent distinct disorders (type I versus type II osteoporosis) although osteopenia is common in both. To determine whether differences in femoral geometry, one of the main determinants of bone quality, might contribute to the heterogeneity in osteoporotic fractures, we obtained dual energy X-ray absorptiometry scans on 210 women age 60 or older, including 105 type I fracture cases, 30 type II patients, and 75 controls. Hip axis length, measured on the scan printout, was significantly increased (p < 0.01) in hip fracture patients compared with women with postmenopausal osteoporosis, whereas femoral neck density (BMD) was equal in both groups. The best discrimination between both fracture types was obtained by a logistic regression model based on age and axis length. Adding BMD to the model did not improve the discriminative power (p = 0.67). These data provide further evidence that geometric characteristics may be implicated in hip fracture risk. Furthermore, these findings suggest that an increase in hip axis length may predispose osteopenic subjects to a femoral localization of fragility fractures, consistent with the postulated heterogeneity in the pathogenesis of osteoporotic fractures.

Absorptiometry, Photon↗

PubMedDate not supplied

In vitro peel/shear bond strength evaluation of orthodontic bracket base design.

OBJECTIVES: The adhesive capacity of 17 different bracket types was evaluated in an in vitro peel/shear test. METHODS: Silane-treated metal bars were used as substrates with all bonding being performed using the orthodontic adhesive Concise. The effect of aluminium oxide air abrasion on the bonding performance of recycled metal bracket bases was evaluated. Morphological examination of the bracket bases was carried out under scanning electron microscopy. Statistics analysis included one-way ANOVA with Tukey's Studentized Range Test, two-way ANOVA and Weibull analysis. RESULTS: Mean peel/shear bond strength values range from 13.9 MPa for Allure Accu Arch, a ceramic bracket type, to 1.6 MPa for the plastic bracket CeramaFlex Advant Edge. Allure Accu Arch performed the best of all the ceramic brackets. However, bracket wing fracture was observed. The metal brackets Mini masters and Omni Arch showed no significant difference in bond strength compared with the ceramic bracket Allure Accu Arch (P < 0.01). CONCLUSION: The type of the bracket base determines its adhesive capacity. Sandblasting the base of recycled metal brackets had no uniform effect.

Adhesiveness↗