Instructions for the use of L-PRF in different clinical indications.

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

[Innovative methods and developments in oral care. L-PRF: from evidence to clinical use]. / Serie: Innovatieve technieken en ontwikkelingen in de mondzorg. L-PRF: van evidence naar toepassingen in de praktijk.

Leukocyte- and platelet-rich fibrin (L-PRF) is a fully autologous biomaterial made from venous blood drawn from the patient. Due to its regenerative potency, antibacterial capacity, and analgesic activity, L-PRF can be used during surgical procedures as a sole biomaterial or as a bioactive additive along with other natural and synthetic biomaterials. There is sufficient scientific evidence available for applying L-PRF for various indications. The preparation protocol of L-PRF is simple, inexpensive and not time-consuming, making it possible to implement it in the daily practice. The type of centrifuge and blood collection tubes used, the settings of the centrifuge (rotation time and force) as well as the time between the different steps in the protocol have an influence on the biological and mechanical properties of L-PRF.

Impact of local and systemic antimicrobials on leukocyte- and platelet rich fibrin: an in vitro study.

The aim of this study was to evaluate the effect of local and systemic administration of antimicrobials to leukocyte- and platelet-rich fibrin (L-PRF). For part A, 16 tubes of venous blood were collected from each of eight systemically healthy subjects. Prior to blood centrifugation, 12 of the 16 tubes were injected with 0.125 ml, 0.25 ml or 0.50 ml metronidazole solution. One set of L-PRF membranes was used to assess the release of vascular endothelial growth factor AB, platelet-derived growth factor, transforming growth factor beta 1, and bone morphogenetic protein 2 at indicated time points. The metronidazole release over time by L-PRF membranes was also evaluated. The remaining L-PRF membranes were placed on the surface of agar plates inoculated with three different periodontal pathogens to determine their antibacterial activity. For part B, another six subjects were enrolled with three subjects taking 2 g amoxicillin and three subjects 500 mg metronidazole as prophylaxis prior to a periodontal treatment. Before and 2 h after consuming one of the prescribed antimicrobials, three tubes of blood were collected for preparing L-PRF membranes. These membranes were used to measure the antibacterial activity against periodontal pathogens. No statistically significant difference could be found in the release of growth factors between L-PRF membranes with and without incorporation of metronidazole solution. The release of metronidazole could be detected up to day 3, however with the highest concentration during the first 4 h. This concentration was dose dependent. The antibacterial capacity of L-PRF membranes increased significantly for both the systemic intake, and after the addition of metronidazole solution to the blood tubes before centrifugation, the latter again dose dependent. The antibacterial capacity of L-PRF against the periodontal pathogens tested can significantly be enhanced by the addition of antimicrobials, without disadvantage for the release of growth factors.

A Prospective, Controlled, Multicenter Study to Evaluate the Clinical Outcome of Implant Treatment in Women with Osteoporosis/Osteopenia: 5-Year Results.

The impact of osteoporosis on implant treatment is still a matter of debate in the scientific community, as it may possibly lead to higher failure rates. As long-term controlled trials are missing, the aim of this study was to verify the long-term outcome of implants placed in patients with systemic osteoporosis. Postmenopausal women in need of implants underwent bone mineral density measurements in hip and spine, using dual X-ray absorptiometry scans. Based on T-scores, they were divided into 2 groups: group O (osteoporosis group) with a T-score ≤-2 or group C (control group) with a T-score of ≥-1. Implants were placed in a 2-stage manner and loaded 4 to 8 wk after abutment surgery. Six months after loading and thereafter yearly, clinical and radiographical parameters were assessed. In total, 148 implants were placed in 48 patients (mean age: 67 y [range, 59-83]). Sixty-three implants were placed in 20 patients (group O) and 85 implants in 28 patients (group C). After 5 y, 117 implants (38 in group O and 79 in the group C) in 37 patients were assessed. Cumulative survival rate on an implant level was 96.5% (group O: 91.5%; group C: 100.0% [ P < 0.05]) and 95.7% (group O: 89.2%; group C: 100.0% [ P > 0.05]) on a patient level. The overall marginal bone-level alterations, after 5 y of loading, were -0.09 ± 0.78 mm (group O: -0.15 ± 0.50 mm; group C: -0.06 ± 0.89 mm) on an implant level and -0.09 ± 0.54 mm (group O: -0.18 ± 0.43 mm; group C: 0.06 ± 0.58 mm) on a patient level ( P > 0.05). Oral implant therapy in osteoporotic patients is a reliable treatment option with comparable osseointegration rates, implant survival, and marginal bone-level alterations after 5 y of functional loading (ClinicalTrials.gov NCT00745121).

L-PRF for increasing the width of keratinized mucosa around implants: A split-mouth, randomized, controlled pilot clinical trial.

BACKGROUND: This study aims to evaluate the use of the leukocyte- and platelet-rich fibrin (L-PRF) membranes in increasing the width of the keratinized mucosa (KM) around implants. MATERIAL AND METHODS: Eight patients in need for bilateral widening of the KM around implants in the lower jaw were recruited for a spit-mouth randomized controlled trial. At the control site, a free gingival graft (FGG) was used, whereas at the other side (test), L-PRF membranes were applied. The primary outcome was the increase in width of KM around the implants. As secondary outcomes, the postoperative pain and surgical time were assessed. The follow-up period was 6 weeks. RESULTS: A significant increase in the total bucco-lingual width of KM in both groups was observed, with 1.3 mm ± 0.9 extra gain (P < .05) for the FGG sites. Shrinkage of the widened areas in this period was 32.1% at the test site and 23.6% at the control site. All values of the postoperative pain scores at the control site were higher than at the test site. The mean surgery time in the test and control group was 29.1 ± 4.8 and 48.1 ± 7.7 minutes, respectively. CONCLUSION: Within the limitations of this randomized controlled trial with split mouth design, it can be concluded that L-PRF can increase the width of KM around implants. Furthermore, the use of L-PRF results in a lower surgical time with less postoperative discomfort and pain for the patients in comparison to the FGG.

Inhibitory control in euthymic bipolar disorder: Event related potentials during a Go/NoGo task.

OBJECTIVES: Patients with bipolar disorder (BD) are reported to have difficulties with inhibition, even in a euthymic state. However, the literature on cortical activity associated with response inhibition in BD remains ambiguous. This study investigates inhibition in euthymic BD using electrophysiological measures, while controlling for effects of specific medications. METHODS: Twenty patients with BD were compared with eighteen healthy controls on a Go/NoGo task while electroencephalogram was recorded. Behavioral and event-related potential (ERP) measurements were analyzed for the two groups. Medication effects were controlled for in the analysis. RESULTS: Patients with BD had marginally reduced NoGo N2 amplitudes and increased NoGo P3 amplitudes compared with healthy controls when patients using benzodiazepines were excluded from the study. No behavioral differences between the groups were found. CONCLUSIONS: Reduced NoGo N2 amplitudes in BD reflect aberrant conflict detection, an early stage of the inhibition process. In addition, increased NoGo P3 amplitudes in BD despite normal task performance reflect an overactive cortical system during a simple inhibition task. SIGNIFICANCE: Difficulties in early stages of inhibition in BD appear to have been compensated by increased cortical activation. This study extends current knowledge regarding cortical activations relating to inhibition in BD.

Oral implant placement and restoration by undergraduate students: clinical outcomes and student perceptions.

INTRODUCTION: Universities are developing and implementing implant dentistry training to prepare dental professionals for the growing treatment needs. This study describes how implant dentistry is taught at the KU Leuven and focuses on implant-related clinical outcomes. Perspectives of participating undergraduate students are analysed with a view to improve oral implant dentistry training. MATERIALS AND METHODS: Implant dentistry training at the KU Leuven consists of theoretical lectures, pre-clinical hands-on workshops and clinical (surgical/prosthetic) experience. Questionnaires were used to investigate the perceptions of students on the educational programme. Radiographs were taken at implant insertion, at healing abutment connection, at restoration/prosthesis insertion and after 1 and 2 years of functional loading. The marginal bone level was measured from the implant-abutment connection to the first visible bone-to-implant contact. RESULTS: One hundred and twelve implants were placed by 56 undergraduate students (61.5% of the total students) in 56 patients. After a follow-up time of 3 years, the cumulative implant survival rate, at implant level, was 97.1%. The mean marginal bone loss after 1 and 2 years in function was 0.35 mm and 0.39 mm, respectively. Eighty percentage of students were satisfied with the training, and they considered this sufficient preparation to perform implant placement under close supervision. CONCLUSIONS: The clinical outcome of implant treatment performed by undergraduate students under close supervision is similar to that reported by experienced clinicians/research teams. Clinical, surgical as well as restorative experience in addition to theoretical and pre-clinical training seems beneficial when implementing implant dentistry in the undergraduate programmes.

[Social cognition in bipolar disorder]. / Sociale cognitie bij bipolaire stoornis.

BACKGROUND: Bipolar disorder is characterised by disturbed mood regulation. Recently, research has focused on cognitive deficits, including social-cognitive deficits, which have a major impact on daily functioning. AIM: To review the recent literature on social cognition in both the symptomatic and the remission phases in bipolar disorder and to discuss the link between social cognition and psychosocial functioning. METHOD: We reviewed the literature systematically using the most important literature databases and cross-references. RESULTS: Deficits in social-cognitive domains such as emotion recognition and Theory of Mind become apparent during both the symptomatic and remission phases. These deficits are influenced by moderating variables such as medication use, clinical symptoms and neurocognitive deficits. Furthermore, in some recent studies these social-cognitive deficits have been linked to poorer functioning. CONCLUSION: In bipolar disorder, social-cognitive deficits are present in different areas and are to a large extent independent of the mood phase. There is an urgent need for more research into the various cognitive domains and into the effect that these have on daily functioning in all phases of bipolar disorder.

CEPHEUS SA: a South African survey on the undertreatment of hypercholesterolaemia.

AIM: The aim of the CEntralised Pan-South African survey on tHE Under-treatment of hypercholeSterolaemia (CEPHEUS SA) was to evaluate the current use and efficacy of lipidlowering drugs (LLDs), and to identify possible patient and physician characteristics associated with failure, if any, to achieve low-density lipoprotein cholesterol (LDL-C) targets. METHODS: The survey was conducted in 69 study centres in South Africa and recruited consecutive consenting patients who had been prescribed LLDs for at least three months. One visit was scheduled for data collection, including fasting plasma lipid and glucose levels. Physicians and patients completed questionnaires regarding their knowledge, awareness and perceptions of hypercholesterolaemia and the treatment thereof. RESULTS: Of the 3 001 patients recruited, 2 996 were included in the final analyses. The mean age was 59.4 years, and 47.5% were female. Only 60.5 and 52.3% of patients on LLDs for at least three months achieved the LDL-C target recommended by the NCEP ATP III/2004 updated NCEP ATP III and the Fourth JETF/South African guidelines, respectively. Being male, older than 40 years, falling into the lower-risk categories, compliance with the medication regimen, and patient knowledge that the LDL-C goal had been reached, were associated with the highest probability of attaining LDL-C goals. CONCLUSION: The results of this survey highlight the sub-optimal lipid control achieved in many South African patients taking lipid-lowering therapy.

[Electric toothbrushes]. / Les brosses à dents électriques.

In the 19th century, the first electric toothbrush was introduced. As years gone by, the design and brushhead movements have been constantly changing. Companies claim that electric toothbrushes are more efficient than manual toothbrushes. In this literature review, the importance of the different brushhead movements, brushing time and brushing force and their impact on microbiology and gingival recession is pointed out. Furthermore, the efficiency of electric toothbrushes is evaluated through the available scientific evidence.

[Dentifrices:an evaluation based on the current literature]. / Dentifrices: évaluation sur base de la littérature actuelle.

Toothpastes remain a frequently used auxilary in oral hygiene. Although some new components have been introduced, the base composition does not differ much between toothpaste types. Concerning toothpastes there is a thin border between cosmetics and drugs and it becomes more and more difficult for oral health care workers to prescribe the right toothpaste for the right patient. Production companies are frequently using commercial advertisements to promote their product. In this way, it's getting more and more difficult for the dentist (and patient) to find the suitable product. This literature review aims to search for scientific evidence for toothpaste components and their clinical use. In this way the review can be used as a compendium for health care workers to make the right choice in prescribing toothpastes. Furthermore all available toothpastes on the Belgian market are listed, following their composition.

[Does good oral hygiene guarantee the maintenance of a health periodontium?]. / Une hygiène bucco-dentaire correcte peut-elle garantir le maintien d'un parodonte sain?

On the last European Workshop for Periodontology, it was accepted that the prevalence of periodontitis in certain regions of Europe and USA has decreased. It remains difficult to phrase a decision concerning the prevalence of periodontitis in general. This article wants to highlight the need of a good oral hygiene and different forms of prevention (primary, secondary & tertiary) in the maintenance of a healthy periodontium. The relationship between gingivitis and tooth loss is pointed out. The prevention is described in the complexity of the periodontitis proces and it's modifying factors. When dealing with different forms of periodontitis (refractory, necrotising gingivitis and periodontitis, agressive periodontitis) prevention needs to be adjusted to the etiology and specific situation. This is also the case in peri-implantitis. This article tends to find a scientific background for oral hygiene and prevention in periodontal disease.

The oxidative metabolism of metoprolol in human liver microsomes: inhibition by the selective serotonin reuptake inhibitors.

OBJECTIVE: Biotransformation of metoprolol to alpha-hydroxymetoprolol (HM) and O-demethylmetoprolol (ODM) is mediated by CYP2D6. The selective serotonin reuptake inhibitors (SSRIs) are known to inhibit CYP2D6. The aim was to study in vitro the potential inhibitory effect of SSRIs on metoprolol biotransformation. METHODS: Using microsomes from two human livers, biotransformation of metoprolol to alpha-hydroxymetoprolol (HM) and O-demethylmetoprolol (ODM) as a function of the concentrations of the SSRIs and of some of their metabolites was studied. RESULTS: The kinetics of the formation of both metabolites are best described by a biphasic enzyme model. The estimated values of Vmax and kM for the high affinity site are for the alpha-hydroxylation in human liver HL-1 32 pmol mg(-1) min(-1) and 75 micromol x l(-1) respectively, and in human liver HL-9 39 pmol mg(-1) x min(-1) and 70 micromol x l(-1) respectively; for the O-demethylation in HL-1 131 pmol mg(-1) min(-1) and 95 micromol x l(-1) respectively, and in HL-9 145 pmol mg(-1) min(-1) and 94 micromol x l(-1) respectively. Quinidine is for both pathways a potent inhibitor of the high-affinity site, with K(i) values ranging from 0.03 to 0.18 micromol x l(-1). Fluoxetine, norfluoxetine and paroxetine are likewise potent inhibitors, with Ki values ranging from 0.30 to 2.1 micromol x l(-1) fluvoxamine, sertraline, desmethylsertraline, citalopram and desmethylcitalopram are less potent inhibitors, with K(i) values above 10 micromol x l(-1). CONCLUSION: The rank order of the SSRIs for inhibition of metoprolol metabolism is comparable to that reported in the literature for other CYP2D6 substrates, with fluoxetine, norfluoxetine and paroxetine being the most potent. These findings need further investigation to determine their clinical relevance.

Effects of dietary corn and olive oil versus coconut fat on biliary cholesterol secretion in rats.

We have studied the effects of dietary corn and olive oil versus coconut fat on bile formation and fluidity of hepatic plasma membranes in rats. After 4 weeks of feeding the purified diets containing 9% (w/w) of the test fats, there was no difference in plasma cholesterol concentration between the dietary groups. The amount of free and esterified cholesterol in the liver was significantly higher in rats fed either corn oil or olive oil as compared with coconut fat. In the rats fed olive oil, but not in those fed corn oil this was associated with lower rates of biliary phospholipid excretion. Bile flow was not differently influenced by the three dietary fats. Hepatic plasma membranes of the rats fed corn or olive oil contained more cholesterol and less phospholipids than those on coconut fat, which was, however, not accompanied by changes in fluidity of the membranes. These results indicate that in rats the type of dietary fat can induce considerable changes in hepatic cholesterol metabolism without affecting plasma cholesterol concentrations, and without consistent effects on biliary cholesterol secretion.

Effects of dietary cholesterol on bile formation and hepatic processing of chylomicron remnant cholesterol in the rat.

We have studied the coupling between hepatic uptake of chylomicron remnant cholesteryl ester and biliary excretion of cholesterol and bile acids in rats, after feeding them a cholesterol-free (control) or a high-cholesterol diet (1% wt/wt) for 2 wk. We equipped rats with permanent catheters in the bile duct, duodenum and heart to allow experiments in unanesthetized, unrestrained animals. Cholesterol feeding induced a 20% increase in plasma cholesterol concentration, a threefold increase in hepatic bile acid synthesis and a 27% increase in bile acid pool size, whereas biliary excretion of cholesterol was decreased by 50%. The enlarged bile acid pool contained relatively less cholic acid and more chenodeoxycholic acid and muricholic acids. [3H]cholesteryl ester-labeled chylomicron remnants (150 micrograms protein per rat) were injected intracardially, and blood and bile were collected for a period of 22 hr. Plasma disappearance of remnants was significantly delayed by cholesterol feeding, probably caused by competition with diet-induced beta-very low density lipoproteins for hepatic uptake. In control rats biliary excretion of chylomicron remnant-derived radioactivity (50% in free cholesterol and 50% in bile acids) showed an initial peak 1 hr after injection (2.4% dose per hour). A second peak (90% in bile acids), amounting to 1.5% of the dose per hour, appeared 11 hr after injection. Total 22-hr excretion of 3H was 22% of the dose. In cholesterol-fed rats chylomicron remnant-derived radioactivity appeared more rapidly in bile, with a peak 1 hr after injection, amounting to 3.5% of the dose per hour. In this case radioactivity was mainly present as bile acid. Total excretion in 22 hr was 27% of the dose. We conclude that chylomicron remnant uptake by the liver is efficiently coupled to bile acid synthesis and biliary excretion, thus providing an efficient pathway for removal of intestine-derived cholesterol. After cholesterol feeding, chylomicron remnant cholesteryl ester is more efficiently converted to bile acids, a mechanism which may contribute to the resistance of rats to diet-induced elevation of plasma cholesterol. In contrast, biliary excretion in the form of free cholesterol, the second main excretory pathway, is significantly decreased by a high-cholesterol diet.

Dietary fish oil-induced changes in intrahepatic cholesterol transport and bile acid synthesis in rats.

Hepatic cholesterol metabolism was studied in rats fed purified diets supplemented (9% wt/wt) with either fish oil (FO) (n-3 fatty acids) or corn oil (CO) (n-6 fatty acids) for 4 wk. Rats were equipped with permanent catheters in heart, bile duct, and duodenum to allow studies under normal feeding conditions. [3H]-cholesteryl oleate-labeled small unilamellar liposomes, which are rapidly endocytosed by hepatocytes, were intravenously injected to label intrahepatic cholesterol pools, and plasma and bile were collected. FO as compared to CO induced a lowering of plasma cholesterol levels by 38% and of triglyceride levels by 69%. This reduction in plasma lipids in FO rats was accompanied by: (a) an increased bile acid pool size (28%); (b) a fourfold increase in the ratio cholic acid/chenodeoxycholic acid in bile; (c) increased biliary excretion of cholesterol (51%); (d) accelerated excretion of endocytosed free cholesterol into bile; (e) accelerated incorporation of endocytosed cholesterol in bile acids; (f) a significant increase in the bile acid-independent fraction of bile flow; and (g) a threefold increase in hepatic alkaline phosphatase activity. The results show that FO induces changes in transport and metabolic pathways of cholesterol in the rat liver, which result in a more rapid disposition of plasma-derived cholesterol into the bile.

The value of the routine chest roentgenogram in the cardiological evaluation of infants and children. A prospective study.

The value of the routine chest roentgenogram was studied in 284 patients, newly admitted to our paediatric outpatient department. Emergency patients were excluded from the study. In 141 cases the initial diagnosis after history, physical examination and ECG was "no heart disease", while in 143 cases it was "heart disease". After a follow up of up to 4 years, 170 children appeared to have "no heart disease" and 114 definite heart disease. In 7.7% of cases the chest roentgenogram made at the first visit to the outpatient department led to a change in policy, whereas in only 3.8% was the chest roentgenogram in someway helpful in establishing the correct diagnosis. Amongst those children with initial diagnosis of innocent murmur, the chest roentgenogram led to a diagnosis of "heart disease" in only 2.8% of cases. It is concluded that for the differentiation "heart disease" or "no heart disease", a chest X-ray film is not indicated. In children with "heart disease" the chest X-ray film is also of little value, and is mostly to be used only for documentation.

Short- and long-term effects of biliary drainage on hepatic cholesterol metabolism in the rat.

The present study concerns short- and long-term effects of interruption of the enterohepatic circulation (EHC) on hepatic cholesterol metabolism and biliary secretion in rats. For this purpose, we employed a technique that allows reversible interruption of the EHC, during normal feeding conditions, and excludes effects of anaesthesia and surgical trauma. [3H]Cholesteryl oleate-labelled human low-density lipoprotein (LDL) was injected intravenously in rats with (1) chronically (8 days) interrupted EHC, (2) interrupted EHC at the time of LDL injection and (3) intact EHC. During the first 3 h after interruption of the EHC, bile flow decreased to 50% and biliary bile acid, phospholipid and cholesterol secretion to 5%, 11% and 19% of their initial values respectively. After 8 days of bile diversion, biliary cholesterol output and bile flow were at that same level, but bile acid output was increased 2-3-fold and phospholipid output was about 2 times lower. The total amount of cholesterol in the liver decreased after interruption of the EHC, which was mainly due to a decrease in the amount of cholesteryl ester. Plasma disappearance of LDL was not affected by interruption of the EHC. Biliary secretion of LDL-derived radioactivity occurred 2-4 times faster in chronically interrupted rats as compared with the excretion immediately after interruption of the EHC. Radioactivity was mainly in the form of bile acids under both conditions. This study demonstrates the very rapid changes that occur in cholesterol metabolism and biliary lipid composition after interruption of the EHC. These changes must be taken into account in studies concerning hepatic metabolism of lipoprotein cholesterol and subsequent secretion into bile.

Dietary cholesterol and fats at a young age: do they influence cholesterol metabolism in adult life?

The effects of dietary cholesterol and fats on cholesterol metabolism later in life were studied in Mongolian gerbils. Three groups were given a basic diet with soybean oil, palm kernel oil amounting to 8.75% (w/w), or the basic diet only. In three other groups, cholesterol (0.05%) was added to the above diets. Measurements were done in animals of the third generation on the diets. On all diets, teh serum cholesterol of the sucklings was increased as compared to the young that were suckled by mothers on the basic diet only, while body cholesterol was highest in sucklings of mothers on the basic diet or palm-kernel-oil-enriched diets. When the diets were replaced by the basic diets at 6 months of age, serum cholesterol was still increased at 12 months of age in animals previously fed on the cholesterol-enriched diets. Tissue cholesterol did not differ. However, after a challenge with cholesterol at that age, the differences in serum cholesterol were not significantly different.