Association of the HALP Score with Dyslipidemia: A Large, Nationwide Retrospective Study

Background and Objectives: Dyslipidemia is a major risk factor for cardiovascular disease (CVD). The identification of new biomarkers that may enhance the risk assessment of lipid abnormalities is a promising approach in improving risk prediction of CVD. There is no information on the association of the hemoglobin, albumin, lymphocyte, and platelet (HALP) score with dyslipidemia. The aim of this study was to investigate the clinical utility of the HALP score in light of dyslipidemia. Materials and Methods: A retrospective analysis of 7192 subjects was initiated to assess the association between the HALP score and disturbed lipid markers. Medians were compared by Mann-Whitney U or Kruskal-Wallis tests and the diagnostic performance and risk assessment were calculated. Results: Median HALP score among all subjects was 53.3, with varying values between males and females. Notably, median HALP was significantly elevated in all forms of dyslipidemia and among males and females irrespective of age. The odds of having elevated HALP score values were significantly higher in all lipid abnormalities. Moreover, HALP score was significantly yet weakly correlated with lipid markers, while the highest diagnostic accuracy of the HALP score was observed with an elevated ratio of total cholesterol to high-density lipoprotein (TC/HDL) (area under the curve, AUC = 0.6411, p < 0.0001). The decision curve analysis (DCA) showed that the HALP score can reliably predict the presence of dyslipidemia. Conclusions: This study demonstrates that the HALP score is a novel, cost-effective index that is associated with a disturbed lipid profile. Further investigation of the nature of this association is needed.

Comprehensive Retrospective Analysis of Colorectal Cancer Incidence Patterns in Saudi Arabia

Colorectal cancer (CRC) is the commonest cancer in Saudi males and the third most common in Saudi females. Although CRC represents a major public health challenge, the resources to evaluate its burden are inadequate. This study aims to elucidate the magnitude of CRC incidence trends in the Saudi population by age, gender, and administrative region. Data for multiple incidence measures were analyzed from the Saudi Cancer Registry (SCR) retrospectively from 2001 to 2018. Temporal trends were further analyzed by age group, gender, administrative region, and globally using joinpoint regression analysis. The number of CRC cases climbed by 335.6% and the disease increased by 56.4% to comprise 12.2% of all cancers cases. The age-standardized incidence rate (ASR) increased by 152% overall, and the median age at diagnosis peaked at 60 and 58 years for males and females, respectively. Riyadh and the Eastern Region had the highest ASR for both genders, peaking at 21.8 and 19.2 for males and 17.4 and 16.5 for females per 100 K population. Our prediction model identified growing trends with annual percentage changes (APCs) of 4.59% in males (CI: 3.1-6.1) and 3.91% among females (CI: 2.4-5.5). Males above 75 years had the highest APC (7.9%, CI: 5.3-10.7), whereas the highest APC among females was found in the age group 70-74 (5.4%, CI: 2.8-8). Globally, APC was the highest for both genders compared to selected countries. CRC incidence is increasing alarmingly in Saudi Arabia and is projected to continue. There is a need for better screening strategies, preventative measures, and awareness-building.

The Role of Immune Checkpoint Inhibitors in Cancer Therapy

Over the years, immune checkpoint inhibitors (CPIs) have become a powerful treatment strategy in the field of cancer immunotherapy. In the last decade, the number of FDA-approved CPIs has been increasing prominently, opening new horizons for the treatment of a wide range of tumor types. Pointedly, three immune checkpoint molecules have been under extensive research, which include cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein-1 (PD-1) and its ligand-1 (PD-L1). Despite remarkable success, not all patients respond positively to therapy, which highlights the complexity of the tumor microenvironment (TME) and immune system. This has led to the identification of molecular biomarkers to predict response and toxicity. In addition, there has been an emerging focus on developing new delivery and targeting approaches for better drug efficacy and potency. In this review, we highlight the mechanism of action of major CPIs, their clinical impact, variation in effectiveness, response prediction, updated clinical indications, current challenges and limitations, promising novel approaches, and future directions.

Breast Cancer Incidence Patterns in the Saudi Female Population: A 17-Year Retrospective Analysis

Background and Objectives: Breast cancer is considered the most commonly diagnosed type of cancer among women globally and in Saudi Arabia. This study aimed to assess breast cancer incidence patterns and trends among the Saudi female population. Materials and Methods: Breast cancer incidence parameters were obtained from the Saudi Cancer Registry (SCR). The data were retrospectively analyzed for the period from 2001 to 2017 to investigate changes in incidence rates. Temporal trends were also analyzed through joinpoint regression analysis and were dissected by age groups and administrative regions. Results: During the specified period, breast cancer jumped by 55% to constitute 30.9% of all cancer cases among Saudi females. The median age at diagnosis increased to reach 51 years at the end of that period, with an overall increase of 6.3%. The overall Age-Standardized Incidence Rate (ASR) escalated by 151.7% from 11.8/100,000 to 29.7/100,000 population for that period. The Eastern region noticeably had the highest ASR and peaked at 52.2/100,000 population. The joinpoint analysis of the ASR showed increased trends, with an annual percent change (APC) of 5.13% (p < 0.05, [95% CI 4−6.3]). An age-specific analysis was also performed and showed that the age group 70−74 years had the highest trend (APC 10.2%, [95% CI 7.2−13.4], p < 0.05). Region-specific analysis revealed that the Jouf region had the highest trend among the regions (APC 8.8%, [95% CI 3.7−14.2], p < 0.05). Conclusions: Our analysis indicates increased breast cancer incidence in Saudi Arabia with an alarming pace. With the existing trend, it is expected that Saudi Arabia will continue to display an increase in breast cancer incidence. Long-term preventive measures and more effective screening strategies are warranted to alleviate the burden of the disease.

Patterns of Dyslipidemia in the Anemic and Nonanemic Hypertensive Saudi Population: A Cross-Sectional Study

Background

Risk factors of cardiovascular disease include dyslipidemia, hypertension (HTN), and anemia. Our objective is to assess the patterns of dyslipidemia in the anemic and non-anemic hypertensive Saudi population.

Methods

A retrospective, cross-sectional study of the gender, blood pressure, lipid markers, and CBC parameters of 3111 subjects, which were retrieved from the database of Al-Borg Medical Laboratories over a six-year period (2014-2019), was carried out. Means were compared among study groups and the prevalence, association, and diagnostic accuracy of lipid markers for HTN were evaluated.

Results

TG, LDL/HDL, and TG/HDL were significantly higher (P < 0.0001) in hypertensives. Anemia reduces TC and LDL (P < 0.0001) in both genders, and reduces all markers and increases HDL (P < 0.01) in male hypertensives. HTN was more prevalent in anemics with high TC than normal TC (38.23% vs 11.17%, P < 0.001) and in non-anemics with high TG than normal TG (56.31% vs 21.22%, P < 0.001). Furthermore, non-anemics with high TG/HDL had the highest risk for HTN (RR = 1.20, 95% CI = 1.1551-1.2473, P < 0.0001). Elevated TC (P = 0.0142), TG (P < 0.0001), TC/HDL (P < 0.0001), LDL/HDL (P < 0.0001), and TG/HDL (P < 0.0001), and low HDL (P < 0.0001) were risk factors for HTN as shown by ORs. In anemics, high TC/HDL, LDL/HDL, and TG/HDL were not. Importantly, only TG and TG/HDL had a discriminating capacity for HTN.

Conclusion

The anemic state of hypertensive Saudi patients influences dyslipidemia which warrants further investigation.

Effectiveness of 0.12% chlorhexidine and a Salvadora persica-based mouthwash in reducing periodontal inflammation and whole salivary IL-1β levels after non-surgical periodontal therapy in young light cigarette-smokers

OBJECTIVE

The aim was to assess the effectiveness of 0.12% chlorhexidine (CHX) and a Salvadora persica (SP)-based mouthwash in reducing periodontal inflammation and whole salivary interleukin (IL)-1β levels after non-surgical periodontal therapy in young light cigarette-smokers.

PATIENTS AND METHODS

Self-reported current cigarette-smokers and never-smokers with periodontal inflammation were included. All patients underwent non-surgical periodontal therapy. Patients were divided into 2 subgroups. In the test- and control-group, patients were advised to rinse with a Salvadora persica-based mouthwash and a non-alcoholic 0.12% CHX twice daily for 2-weeks, respectively. Full-mouth plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment loss (AL) and whole salivary IL-1β were measured at baseline and at 3-months' follow-up. Significance was set at p<0.01.

RESULTS

34 cigarette-smokers and 34 never-smokers were included. At 3-months of follow-up, PI, PD, and clinical AL were comparable with their respective baseline values among cigarette-smokers. In never-smokers, there was a significant reduction in scores of PI (p<0.01), GI (p<0.01) and PD (p<0.01) at 3-months of follow-up compared with baseline. At 3-months of follow-up, there was no significant difference in PI, GI, PD, and clinical AL among never-smokers in the test- and control-groups. Among never-smokers, there was a significant reduction in whole salivary IL-1β levels at 3-months' follow-up (p<0.01).

CONCLUSIONS

Usage of 0.12% CHX or a S. persica-based mouthwash following NSPT is ineffective in controlling periodontal inflammation and reducing whole salivary IL-1β in young light cigarette-smokers compared with never-smokers.

Induction of hemolysis and eryptosis by occupational pollutant nickel chloride is mediated through calcium influx and p38 MAP kinase signaling

OBJECTIVES

Nickel (Ni) is an abundant environmental hazard and an occupational pollutant. Exposure to Ni compounds is prevalent in electroplating workers and in the printing industry, among others. The toxicity of Ni manifests as dermatological, gastrointestinal, respiratory, allergic, and cardiovascular symptoms. In particular, hyperbilirubinemia and reticulocytosis have been detected in intoxicated subjects; an observation possibly implicating selective red blood cell (RBC) toxicity. Herein, the interaction of nickel chloride (NiCl2) with human RBCs and associated molecular mechanisms are described.

MATERIAL AND METHODS

Cells from healthy donors were incubated for 24 h at 37°C in the presence or absence of 0.5‒10 mM of NiCl2, and cytotoxicity was determined through hemoglobin leakage by colorimetry under different experimental conditions. Eryptotic markers were also identified by flow cytofluorometry using Annexin-V-FITC tagging for phosphatidylserine (PS) exposure, light scatter properties for cellular dimensions, Fluo4/AM labeling for intracellular calcium, and H2DCFDA staining for reactive oxygen species (ROS). Additionally, small molecule inhibitors were used to probe the signaling pathways involved.

RESULTS

It was found that NiCl2 at 10 mM caused profound intracellular calcium overload and significant calcium-dependent hemolysis. Also, NiCl2 reduced forward scatter and increased side scatter, Annexin- positive cells, and ROS levels. Importantly, NiCl2-induced hemolysis was significantly attenuated by the exclusion of extracellular calcium, and in the presence of p38 MAP kinase (MAPK) inhibitor SB203580.

CONCLUSIONS

It is concluded that NiCl2 induces p38 MAPK-dependent hemolysis, and stimulates the canonical features of premature eryptosis. This report presents the first description of the molecular mechanisms underlying the hemolytic and eryptotic potential of NiCl2 and, thus, may explain changes in hematological parameters observed in poisoning victims. Int J Occup Med Environ Health. 2022;35(1):1-11.

Geraniin inhibits whole blood IFN-γ and IL-6 and promotes IL-1β and IL-8, and stimulates calcium-dependent and sucrose-sensitive erythrocyte death

Correlations between circulating cytokine levels and disease states are well established, and pharmacological modulation of the immune response is thus an important aspect of the assessment of investigational new drugs. Moreover, chemotherapy-related anemia is a major obstacle in cancer treatment. Geraniin (GRN), a tannin extracted from Geranium and other plants, possesses promising antitumor potential. However, the effect of GRN on whole blood (WB) cytokine response and RBC physiology remains unexplored. Heparinized blood from consented, healthy adults was challenged with 100 ng/mL of lipopolysaccharide (LPS) with and without pretreatment with 10 μM of GRN for 24 h at 37 °C, and tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-8, and IL-10 were assayed by ELISA. Moreover, single-cell RBC suspensions were treated with 5-100 μM of GRN for 24 or 48 h at 37 °C and cytotoxicity and canonical eryptotic markers were examined by flow cytometry. It was revealed that GRN significantly attenuated LPS-induced IFN-γ levels, increased IL-1β, decreased IL-6 only in absence of LPS, and aggravated LPS-induced IL-8 while together with LPS significantly diminished IL-10. Furthermore, GRN induced dose-responsive, Ca²⁺-dependent, and sucrose-sensitive hemolysis, along with phosphatidylserine exposure and Ca²⁺ accumulation with no appreciable cell shrinkage or oxidative damage. GRN was also selectively toxic to platelets, significantly delayed reticulocyte maturation, and significantly disrupted leukocyte proportions. In conclusion, GRN regulates the WB cytokine response and promotes premature hemolysis and eryptosis. This study provides insights into the therapeutic utility of GRN in a highly relevant cellular model system.

Antiproliferative Wnt inhibitor wogonin prevents eryptosis following ionophoric challenge, hyperosmotic shock, oxidative stress, and metabolic deprivation

Anemia is a common complication of chemotherapy and may arise due to premature or suicidal death of red blood cells (RBCs). Prevention of RBC death thus lends itself as a promising strategy to counteract anemia. Wogonin (WGN; 5,7-dihydroxy-8-methoxyflavone) is a Wnt inhibitor derived from Scutellaria baicalensis plant with potent cytotoxic and antitumor potential. However, the nature of interaction of WGN with human RBCs is unknown. RBCs from healthy participants were exposed to different hemolytic and eryptotic stimuli for 24 or 48 hr at 37°C in the presence and absence of 100 μM WGN. Calcium overload was induced by 2 μM ionomycin, hyperosmotic shock with excessive sucrose, oxidative stress by 2-phenethyl isothiocyanate (PEITC), and metabolic deprivation by exclusion of glucose. Hemolysis was estimated from extracellular hemoglobin, phosphatidylserine (PS) exposure by Annexin V-FITC, intracellular calcium by Fluo4/AM, and oxidative stress by 2',7'-dichlorodihydrofluorescein diacetate (H₂ DCFDA). While WGN did not rescue the cells from the hemolytic activity of ionomycin, it reduced PS externalization by interfering with calcium influx under both ionomycin treatment and metabolic exhaustion. WGN also significantly inhibited PS exposure upon hyperosmotic shock, but the effect was independent of calcium entry. Moreover, WGN exhibited antihemolytic and anti-eryptotic activities against PEITC without appreciable reduction in ROS levels. Altogether, WGN prevents PEITC-induced hemolysis and suppresses eryptosis due to calcium accumulation, hyperosmotic shock, oxidative stress, and metabolic exhaustion. These novel insights may open new avenues into the therapeutic application of WGN for conditions in which anemia is commonly encountered, most notably cancer. PRACTICAL APPLICATIONS: The herbal supplement Sho-Saiko-To (Xiaochaihu-tang) is commonly prescribed to relieve symptoms of liver disease. Flavonoids from the herbal constituents of Sho-Saiko-To have demonstrated considerable anti-inflammatory, antioxidant, antimicrobial, antitumor, and immunomodulatory properties. In this work, we identify WGN, a major flavonoid in Sho-Saiko-To, as a novel inhibitor of hemolysis and eryptosis of human erythrocytes. Since inordinate erythrocyte death is a major obstacle in therapeutic drug development, our findings argue for the use of WGN as a natural alternative, either as a primary or an adjuvant drug, for a wide assortment of pathological conditions including cancer.

Bioymifi, a novel mimetic of TNF-related apoptosis-induced ligand (TRAIL), stimulates eryptosis

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is a cytokine that initiates apoptosis upon binding to death receptor 5 (DR5) on cancer cells. Small molecule TRAIL mimetics have therefore been investigated as promising chemotherapeutic agents. Since anemia of chemotherapy is common, our goal is to investigate the hemolytic and eryptotic properties of novel DR5 agonist bioymifi (BMF) and identify the underlying molecular mechanisms. Whole blood (WB) was stimulated with 100 μM of BMF, whereas red blood cells (RBCs) were treated with 10-100 μM of BMF for 24 h at 37 °C. WB was analyzed for RBC, leukocyte, and platelet indices, while RBCs were examined for hemolysis by light absorbance of free hemoglobin, membrane scrambling by Annexin V-FITC, calcium by Fluo4/AM, cellular morphology by light scatter, and oxidative stress by 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA) using flow cytometry. Caspase inhibitor Z-VAD-FMK, p38 inhibitor SB203580, casein kinase 1α inhibitor D4476, receptor-interacting protein 1 inhibitor necrostatin-2, reduced glutathione, or cyclooxygenase (COX) inhibitor aspirin were added accordingly. BMF exerted dose-responsive, calcium-independent hemolysis, reduced RBC hemoglobin, significantly increased Annexin V-, Fluo4-, and DCF-positive cells, along with a dual effect on forward and side light scatter. Notably, the cytotoxic potential of BMF was significantly mitigated upon pharmacological inhibition of p38. Furthermore, BMF exhibited selective toxicity to eosinophils and significantly diminished reticulocyte hemoglobin content. Altogether, these novel findings highlight the adverse outcomes of BMF exposure on RBC physiology and provide the first toxicological assessment of BMF as an antitumor agent.

Calcium-oxidative stress signaling axis and casein kinase 1α mediate eryptosis and hemolysis elicited by novel p53 agonist inauhzin

Inauhzin (INZ) is a novel p53 agonist with antitumor activity. Anemia is a common side effect of chemotherapy and may arise from red blood cell (RBC) hemolysis or eryptosis. In this study, we investigate the mechanisms of INZ toxicity in human RBCs. RBCs were isolated from healthy donors and treated with antitumor concentrations of INZ (5-500 μM) for 24 h at 37 °C. Hemoglobin was photometrically measured, and cells were stained with Annexin-V-FITC for phosphatidylserine (PS), Fluo4/AM for calcium, and 2',7'-dichlorodihydrofluorescein diacetate (H₂DCFDA) for oxidative stress. INZ caused significant dose-responsive, calcium-dependent hemolysis starting at 40 μM. Furthermore, INZ significantly increased Annexin-positive cells and Fluo4 and DCF fluorescence. The cytotoxicity of INZ was also significantly mitigated in presence of D4476. INZ possesses hemolytic and eryptotic potential characterized by cell membrane scrambling, intracellular calcium overload, cell shrinkage, and oxidative stress secondary to calcium influx from the extracellular space.

Reprogramming of erythrocyte lifespan by NFκB-TNFα naphthoquinone antagonist β-lapachone is regulated by calcium overload and CK1α

The pathophysiology of chemotherapy-associated anemia, prevalent in at least 75% of patients, remains difficult to establish. Chemotherapy-related anemia is attributed in part to eryptosis, and it is therefore of considerable interest to interrogate the toxicity of investigative anticancer compounds to red blood cells (RBCs). Beta-lapachone (LAP), an anthraquinone extracted from the bark of Lapacho tree (Tabebuia avellanedae), is effective against a myriad of cancer cells. However, the toxicity of LAP to RBCs remains unexplored. Hemoglobin leakage as a surrogate for hemolysis was photometrically measured, while flow cytometry was employed to capture phosphatidylserine (PS) exposure with Annexin-V-FITC, calcium levels with Fluo4/AM, cell size by forward scatter (FSC), and oxidative stress by H2DCFDA. Our results show that LAP, at antitumor levels (10-30 µM), induces dose-dependent hemolysis secondary to calcium influx from the extracellular space. Moreover, LAP stimulates eryptosis, as evident from PS exposure, which is associated with reduced cell volume and intracellular calcium overload. Importantly, it is also revealed that the cytotoxicity of LAP is mediated through casein kinase 1α. Altogether, this report shows, for the first time, that LAP possesses both hemolytic and eryptotic potential against RBCs that necessitates careful application in chemotherapy. PRACTICAL APPLICATIONS: Lapacho is a widely consumed herbal tea with origins in the Tabebuia avellanedae tree endogenous to South America. LAP is one of the active ingredients in lapacho with promising antitumor potential. We show that LAP is cytotoxic to human RBCs by virtue of eryptosis and hemolysis, and we identify associated molecular mechanisms. Given that these two manifestations are known to contribute to chemotherapy-induced anemia, our study provides invaluable insights into the suitability of LAP in cancer management and sheds some light on possible strategies to limit its undesirable side effects.

Stimulation of calcium influx and CK1α by NF-κB antagonist [6]-Gingerol reprograms red blood cell longevity

Chemotherapy-induced anemia (CIA) is a major obstacle in cancer management. Although the mechanisms governing CIA are poorly understood, recent efforts have identified suicidal erythrocyte (red blood cell, RBC) death as a possible cause of CIA. [6]-Gingerol (GNG), a polyphenol extracted from Zingiber officinale plant, exhibits a wide array of biological activities including antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, and anticancer activities, in vitro and in vivo. However, the potential toxicity of GNG to human RBCs remains unexplored. RBCs from heparinized blood were isolated by centrifugation and exposed to antitumor concentrations (10-100 µM) of GNG for 24 hr at 37°C. Hemolysis was calculated from hemoglobin leakage in the supernatant (λ_max  = 405 nm), while cytofluorometric analysis of eryptosis employed Annexin-V-FITC to detect phosphatidylserine (PS) exposure, forward scatter (FSC) to estimate cell volume, Fluo4/AM to measure calcium activity, and H₂ DCFDA to assess oxidative stress. Moreover, zVAD(OMe)-FMK, SB203580, necrostatin-2, staurosporin, and D4476 were used to identify signaling pathways responsive to GNG. GNG induced significant hemolysis at 100 µM, independently of extracellular calcium, and increased Annexin-V-FITC fluorescence that was thoroughly abrogated without extracellular calcium. GNG also enhanced Fluo4 fluorescence and reduced FSC, but had no significant effect on DCF fluorescence. Importantly, the presence of D4476 significantly attenuated GNG-induced hemolysis. In conclusion, GNG stimulates premature RBC death characterized by loss of membrane asymmetry, elevated cytosolic calcium, cell shrinkage, and casein kinase 1α activation. Blocking the activity of calcium channels or CK1α may, therefore, ameliorate the toxic effects of GNG on RBCs. PRACTICAL APPLICATIONS: This report presents a safety assessment of GNG as a chemotherapeutic agent and highlights the novel toxicity of GNG to human RBCs. Our findings provide novel insights that may lead to more efficient utilization of GNG in chemotherapy. Specifically, our data revealed the involvement of calcium channels and casein kinase 1α in mediating GNG-induced premature RBC death, and, therefore, inverse agonists or inhibitors of either pathway may be used as pharmaceutical adjuvants to attenuate the toxic effects of GNG.

Novel nuclear localization of fatty acid synthase correlates with prostate cancer aggressiveness

Fatty acid synthase is up-regulated in a variety of cancers, including prostate cancer. Up-regulation of fatty acid synthase not only increases production of fatty acids in tumors but also contributes to the transformed phenotype by conferring growth and survival advantages. In addition, increased fatty acid synthase expression in prostate cancer correlates with poor prognosis, although the mechanism(s) by which this occurs are not completely understood. Because fatty acid synthase is expressed at low levels in normal cells, it is currently a major target for anticancer drug design. Fatty acid synthase is normally found in the cytosol; however, we have discovered that it also localizes to the nucleus in a subset of prostate cancer cells. Analysis of the fatty acid synthase protein sequence indicated the presence of a nuclear localization signal, and subcellular fractionation of LNCaP prostate cancer cells, as well as immunofluorescent confocal microscopy of patient prostate tumor tissue and LNCaPs confirmed nuclear localization of this protein. Finally, immunohistochemical analysis of prostate cancer tissue indicated that nuclear localization of fatty acid synthase correlates with Gleason grade, implicating a potentially novel role in prostate cancer progression. Possible clinical implications include improving the accuracy of prostate biopsies in the diagnosis of low- versus intermediate-risk prostate cancer and the uncovering of novel metabolic pathways for the therapeutic targeting of androgen-independent prostate cancer.

The effects of in-office reconditioning on the morphology of slots and bases of stainless steel brackets and on the shear/peel bond strength

OBJECTIVES

To compare the effect of five in-office bracket reconditioning methods on: (i) bracket slot width and interwing gap measurements; (ii) the appearance of the bracket bases under scanning electron microscope (SEM), and; (iii) shear/peel bond strength (SPBS).

SETTING

Ex vivo study.

METHOD

One hundred and twenty-five brackets were initially bonded and were divided into five experimental groups and reconditioning by the following methods: (i) adhesive grinding using green stone (Gp II); (ii) sandblasting (Gp III); (iii) direct flaming (Gp IV); (iv) using the BigJane machine (Gp V), and; (v) application of Buchman method (Gp VI).

OUTCOMES

Distortion of the brackets. Scanning electron microscopy of three representative specimens from each group. The remaining brackets were rebonded, then shear/peel forces to failure were measured (SPBS).

RESULTS

The ANOVA and multiple comparison test exhibited a statistical, but not clinical, significant increase in the bracket measurements of Group VI. There was a significant reduction (28%) in the SPBS of Group II. Under the SEM, the wire mesh structure was maintained; however, the amount of adhesive remnants greatly varied among the groups.

CONCLUSIONS

Although none of the in-office reconditioning methods employed adversely affected the bracket base and/or the bracket measurements, reconditioning with a green stone was not effective. Sandblasting method and direct flaming are recommended because of simplicity and time-saving advantages.