[Oral medicine 5. Dietary counselling and psycho-social aspects of chemosensory disorders]. / Oral medicine 5. Voedingsadviezen bij en psychosociale aspecten van smaak - en reukstoornissen.

Chemosensory disorders may result in loss of body weight and sometimes in gain of body weight. Therefore, dietary advice is an essential part of the counselling and treatment ofpatients with a chemosensory disorder. In cases involving a chemosensory disorder, a distinction has to be made between general dietary advice and advice during and after a patient's period of chemotherapy or radiotherapy. The aim of dietary advice is the improvement ofa patient's nutritional condition and the patient's well-being. In case of serious problems related to dealing with a chemosensory disorder, psycho-social counselling may be considered.

[Oral medicine 4. Clinical aspects and treatment of taste and smell disorders]. / Oral medicine 4. Klinische aspecten, gevolgen en behandeling van smaak- en reukstoornissen.

Taste and smell perception are closely related. Many chemosensory disorders which result in faulty taste are in fact smell disorders. Causes ofchemosensory disorders which call for attention are ageing, medication, natural proteins, burning mouth syndrome, nerve injuries, aerate disorders in the neighbourhood of the sense ofsmell, damage to the smell epithelium, and oncologic diseases or their treatment. A chemosensory disorder has implications for food delight and psychological well-being, may lead to weight loss or increase and to deficient intake of vitamins and minerals. A chemosensory disorder can be treated by medication, surgical intervention, improvement of oral health, smell rehabilitation, and dietary advice.

[Oral medicine 3. Anatomy, physiology and diagnostic considerations of taste and smell disorders]. / Oral medicine 3. Anatomie, fysiologie en diagnostische overwegingen bij smaak- en reukstoornissen.

Taste and smell perception are closely related. The taste perception is performed by taste buds which can distinguish salt, sour, sweet, bitter, and umami. Moreover, 2,000-4,000 smells can be recognized. Many taste disorders are in fact smell disorders. Saliva affects taste perception because it serves as a solvent for taste substances and as a protecting agent for the taste receptors. Therefore, hyposalivation leads to a reduction in taste perception, in which the concentration of zinc ions and specific proteins in saliva play an important role. In addition, zinc and iron deficiencies may cause diminished taste and smell perception.

[Influence of sports on saliva]. / Invloed van sport op speeksel.

Physical exertion, such as practicing sports, may have an influence on the secretion and composition of saliva. As a result of intensive physical exertion, the saliva immunoglobulin concentration decreases and the concentration of protein--the output of protein (mg/min), however, remains constant--and the viscosity of the saliva increase, while the watery secretion decreases. Moreover, saliva testosterone levels decrease and salivary cortisol levels increase. The saliva Na+, K+, Ca2+ and PO4(3-) concentrations increase slightly or remain unchanged. After a single physical exertion, the alterations are reversible and the values return to baseline within a few hours. In the case of long lasting intensive physical exertions, for instance lasting several months, particularly the decrease in the concentration of the most prevalent immunoglobulins in saliva (s-IgA) seems to have a more permanent character. This has a detrimental effect on the immunological defence, which may reduce oral as well as upper respiratory tract health. Complaints about this are not uncommon among serious athletes who are active at a high competitive level. Among these athletes, the combination of changes in the composition and secretion of saliva, together with intense mouth-breathing and an adjusted diet and drinking habits carry a higher risk of developing caries and erosion. However, in case of decent oral health selfcare, the detrimental effects on oral health can be prevented.

[Behçet's disease]. / Ziekte van Behçet.

Behçet's disease is a multisystem inflammatory disorder, characterized by recurrent oral and genital ulceration and uveitis. Additionally, skin lesions, vasculitis, and arthritis may occur. The disease is chronic, with exacerbations and remissions. Treatment of Behcet's disease is symptomatic depending on the symptoms and their severity. Oral ulcers are seen in 98% of patients with Behçet's disease. Some aspects of oral health, such as the amount of plaque and the presence of periodontal disease, and possibly also caries, are more prevalent in patients with the disease when compared to healthy persons. All oral health aspects will probably benefit from good oral health care. Medications which can be employed for treatment of the various symptoms of the disease are colchicine, corticosteroids, immunosuppressives, cyclosporine, pentoxyfylline, anticoagulants, and thalidomide.

[Painful palate and xerostomia after using paroxetine]. / Pijnlijk palatum en xerostomie na medicatie met paroxetine.

This article presents the case of a 58-year-old woman with diabetes mellitus type 2 who, for one and a half years, had been using paroxetine, a specific serotonin re-uptake inhibitor, to reduce a depression. She complained of xerostomia, dry eyes, and pain of the palate. In the middle of the hard palate a circumscribed, erythemous mucosal lesion was observed. This painful spot had developed, according to the woman, virtually immediately after she had begun to use the medication with paroxetine. The salivary flow rates were reduced when compared with well-known reference values. The diagnosis was hyposalivation. After substitution of paroxetine by lithium, the painful palate and xerogenic complaints disappeared. This case report suggests a causal relationship between, on the one hand, paroxetine and other serotonin re-uptake inhibitors and, on the other, atypical oral pain as well as hyposalivation.

[Electromagnetic interference of electrical dental equipment with cardiac pacemakers]. / Elektromagnetische interferentie van tandheelkundige apparatuur met een pacemaker.

Eight different electrical dental appliances were tested at different intervals for their ability to interfere with the function of a contemporary cardiac pacemaker. The normal atrial and ventricular pacing was inhibited by an ultrasonic bath cleaner at a distance of less than 15 cm. In contrast, a dental chair, an electrosurgical unit, an ultrasonic tooth scaler, 2 handpieces, and 2 amalgamators failed to produce electromagnetic interference at the minimum distance of 2.5 cm. In conclusion, the results suggest that normal clinical use of dental electrical equipment does not have any significant effect on the cardiac pacemaker tested.

[Ecstasy use and oral health]. / Ecstasygebruik en mondgezondheid .

Ecstacy is a frequently used drug, especially by young adults in the big cities.Therefore, it is likely that dentists might be confronted with individuals that use XTC. This review of the literature describes the systemic and oral effects of XTC. Life-threatening complications include hyperthermia, hyponatreaemia and liver failure. In addition, psychotic episodes, depression, panic disorders and impulsive behaviour have been reported. Oral effects include mucosal changes, xerostomia and an increased risk of developing dental erosion and bruxism. Finally, the potential use of saliva for detection of XTC is discussed.

Design of a peptibody consisting of the antimicrobial peptide dhvar5 and a llama variable heavy-chain antibody fragment.

Immunoconjugates have been widely studied as potential therapeutics for infectious diseases to direct unspecific antimicrobials to pathogens. In this study, the recombinant approach was used for expression of the immunoconjugate composed of the variable domain of a llama heavy-chain antibody (VHH) against Streptococcus mutans and dhvar5, a synthetic antimicrobial peptide. Before cloning, the impact of the elongation of the peptide termini on its biological activity was evaluated by chemical synthesis of the N- or C-termini extended dhvar5 peptides. As the elongation of the C-terminus had a greater influence on decline of the antimicrobial activity, the N-terminal fusion was designed. To promote in vivo release of the active peptide, a factor Xa cleavage site was inserted between VHH and dhvar5. Propagation of transformed Escherichia coli with the constructed plasmid was only possible in the absence of isopropyl beta-D-thiogalactoside (IPTG). Although these data demonstrate that the diminished antimicrobial activity of dhvar5 by the N-terminal fusion to VHH was not sufficient for the protection of the bacterial host cells against the peptide lethal effect, an insight into propeptides biological activities may be beneficial not only for new and more successful rearrangement of the VHH-dhvar5 immunoconjugate construct, but also design of the other recombinant molecules composed of peptides toxic to host cells.

[Oral health in patients with chronic renal failure]. / Nierfalen en mondgezondheid.

In The Netherlands the incidence of chronic renal failure is approximately 1 in 10.000. In this review the causes of chronic renal failure and the medical treatment using hemodialysis, peritoneal dialysis or kidney transplantation, are discussed. Moreover, an overview of the oral manifestations of chronic renal failure and the implications for dental treatment is given.

The effect of the antimicrobial peptide, Dhvar-5, on gentamicin release from a polymethyl methacrylate bone cement.

The objective of this study was to investigate the release mechanism and kinetics of the antimicrobial peptide, Dhvar-5, both alone and in combination with gentamicin, from a standard commercial polymethyl methacrylate (PMMA) bone cement. Different amounts of Dhvar-5 were mixed with the bone cement powders of Osteopal and the gentamicin-containing Osteopal G bone cement and their release kinetics from the polymerized cement were investigated. Additionally, the internal structure of the bone cements were analysed by scanning electron microscopy (SEM) of the fracture surfaces. Secondly, porosity was investigated with the mercury intrusion method and related to the observed release profiles. In order to obtain an insight into the mechanical characteristics of the bone cement mixtures, the compressive strength of Osteopal and Osteopal G with Dhvar-5 was also investigated. The total Dhvar-5 release reached 96% in the 100 mg Dhvar-5/g Osteopal cement, whereas total gentamicin release from Osteopal G reached only 18%. Total gentamicin release increased significantly to 67% with the addition of 50mg Dhvar-5/g, but the Dhvar-5 release was not influenced. SEM showed an increase of dissolved gentamicin crystals with the addition of Dhvar-5. The mercury intrusion results suggested an increase of small pores (< 0.1 microm) with the addition of Dhvar-5. Compressive strength of Osteopal was reduced by the addition of Dhvar-5 and gentamicin, but still remained above the limit prescribed by the ISO standard for clinical bone cements. We therefore conclude that the antimicrobial peptide, Dhvar-5, was released in high amounts from PMMA bone cement. When used together with gentamicin sulphate, Dhvar-5 made the gentamicin crystals accessible for the release medium presumably through increased micro-porosity (< 0.1 microm) resulting in a fourfold increase of gentamicin release.

[Oral conditions in swimmers]. / Orale aandoeningen bij zwemmers.

Swimmers, for several hours a week in contact with pool-water, may develop two different types of pool-water related oral conditions: dental erosion and dental staining. Dental erosion may occur when the acidity of the pool-water is below a pH-value of 5, dental staining when the pH-value of the pool-water is above 6.5. Of the two conditions mentioned, dental erosion is the most harmful, because it involves an irreversible process. The clinical significance is clarified by a few case-reports. In Dutch pools, the pH-value of the pool-water has to be checked daily. Therefore, among Dutch swimmers there is only a slight possibility of arising oral conditions caused by pool-water.

[Research methods in dentistry 2. Methods for determining the flow rate of saliva]. / Onderzoeksmethoden in de tandheelkunde 2. Methoden voor het meten van de afgiftesnelheid van speeksel.

For patients with complaints of either hyposalivation or hypersalivation, or saliva with altered properties, the secretory flow rate can be determined in an easy way to study whether abnormalities are detectable. It is most simple to measure the flow rate of whole saliva. After collection of saliva the oral fluid can be analyzed on rheological properties, such as viscosity and elasticity and also on pH and its chemical composition. Oral fluid is the combined fluid in the oral cavity mainly composed of glandular salivas, and in addition crevicular fluid and serum exsudate. For collection of oral fluid it is of crucial importance to standardize the conditions. The diverse collection methods and their application for patient research with oral complaints are described.

Salivary proteins: protective and diagnostic value in cariology?

Saliva is essential for a lifelong conservation of the dentition. Various functions of saliva are implicated in the maintenance of oral health and the protection of our teeth: (i) The tooth surface is continuously protected against wear by a film of salivary mucins and proline-rich glycoprotein. (ii) The early pellicle proteins, proline-rich proteins and statherin, promote remineralization of the enamel by attracting calcium ions. (iii) Demineralization is retarded by the pellicle proteins, in concert with calcium and phosphate ions in saliva and in the plaque fluid. (iv) Several salivary (glyco)proteins prevent the adherence of oral microorganisms to the enamel pellicle and inhibit their growth. (v) The salivary bicarbonate/carbonate buffer system is responsible for rapid neutralization of acids. An overview is presented on the major antimicrobial systems in human saliva. Not only the well-known major salivary glycoproteins, including mucins, proline-rich glycoprotein and immunoglobulins, but also a number of minor salivary (glyco)proteins, including agglutinin, lactoferrin, cystatins and lysozyme, are involved in the first line of defense in the oral cavity. Besides, small cationic antimicrobial peptides, e.g. defensins, cathelicidin and the histatins, have come into focus. These are potentially suited as templates for the design of a new generation of antibiotics, since they kill a broad spectrum of microorganisms, while hardly evoking resistance, in contrast to the classical antibiotics.

[Influence of teas with fruit aroma and ice teas on pH and buffer capacity of saliva]. / De invloed van 'vruchten'- en ijsthee op de pH en buffercapaciteit van speeksel.

A number of teas with fruit aroma and ice teas has been tested on erosivity. The teas with a fruit taste have at their drinking temperature (45 degrees C) a pH between 6.2 to 7.4. Even teas with a citron or citrus flavour are neutral. The most acidic tea tested has a mango-peach-taste, but contains no buffer system. After mixing 1 ml of total saliva up to 10 ml tea or by rinsing the oral cavity with tea the pH of oral fluid was hardly lowered (minimum 6.3). In contrast, ice teas are rather acidic (pH < 4) and have a strong buffer capacity. Rinsing the oral cavity with 5 ml ice tea resulted in a decrease of the pH of the oral fluid to 4.1-4.9. However, within 2 minutes the pH in the oral fluid was already increased to 5.9-7.1 and after 5 minutes to 6.3-7.1. In other words, the teas with fruit aroma, based on organic taste components do not have an erosive potential. On the other hand, ice teas decrease the pH of the oral fluid drastically to a level that they become erosive. Therefore, from a dental point of view, teas with only a taste of fruit can be advised to replace drinking of soft drinks, but ice teas not.

[A patient with Prader-Willi syndrome. Characteristics, oral consequences and treatment options]. / Een patiënt met het Prader-Willi-syndroom. Kenmerken, orale gevolgen en behandelmogelijkheden.

A dentist referred a 32-year-old man with the Prader-Willi syndrome to a center for special dental care because of the poor cooperation of the patient, progressive toothwear and advanced palatal trauma. The dental problems were, among others, caused by the disto-relation (Class II-2), a poor oral hygiene, the frequency of sugar intake, oesophageal reflux and a strongly reduced salivary pH of 5.5. Treatment of the dentition was established by minimal invasive and adhesive dentistry.

[Enduring oral dryness after acne treatment]. / Blijvend een droge mond na behandeling van acne.

Medication influences the salivary flow rate frequently. In this paper a 26-year old patient is described, who used a systemic retinoid (a vitamin A derivate) when he was 18 years old. Since then, irreversible xerostomia was present. The oral complaints have been monitored during three years. Saliva was collected to assess the salivary flow rate and pH. The visco-elasticity of unstimulated whole saliva was high. This indicates a relatively low contribution of the gl. parotidea and a high mucin concentration in the collected saliva. Furthermore, parafilm only slightly stimulated the salivary flow rate. On the other hand, application of a 4% citric acid solution raised the flow rate to normal levels, without any delay. The medical history revealed no factors which could explain the the severe oral dryness and low salivary flow rate in rest. It was concluded that the low salivary flow rates and xerostomia might be related to the previous use of isotretinoin (Roaccutane). It is suggested to register and monitor the use of medication in patients with sudden oral health changes.

Release of antimicrobial peptide Dhvar-5 from polymethylmethacrylate beads.

Osteomyelitis is still a major cause of morbidity and remains a difficult complication to treat in orthopaedic surgery. The treatment of choice is a combination of systemic and local antibiotics. The insertion of gentamicin-loaded polymethylmethacrylate (PMMA) beads into the bone results in high local concentrations of gentamicin and low systemic concentrations. However, the effectiveness of this treatment is being hampered by the emergence of antimicrobial resistance. New antimicrobial agents are therefore needed. One new class of promising antibiotics is antimicrobial peptides (AMP). Derived from natural human peptides, these have a low tendency to induce antimicrobial resistance. Dhvar-5 is an antimicrobial peptide based on histatin-5, which is found in human saliva and consists of 14 amino acids. It has demonstrated bactericidal activity in vitro. In order to develop a new local treatment using Dhvar-5 for osteomyelitis, we investigated its release from PMMA beads and its antimicrobial activity against a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA) before and after release from PMMA beads. Specific amounts of Dhvar-5 were incorporated into PMMA mini beads, containing 120, 600 and 1200 microg of Dhvar-5, respectively. Dhvar-5 was released from the beads in all three groups. Total release from the 120 microg beads was 9 microg per bead after 7 days. However, the release per bead in the 600 and 1200 microg beads was far more, respectively, 416 and 1091 microg over a 28 day period. After release, the Dhvar-5 also retained its antimicrobial activity against MRSA. On the basis of these data we conclude that the amount of Dhvar-5 release from PMMA beads is not proportionate to the amount incorporated; instead, it demonstrated an exponential relationship to the amount of total peptide released. Furthermore, the released peptide remained biologically active against a clinical isolate of MRSA.