Calcium deficiency, pregnancy and lactation in rats

Adult female rats were subjected to severe calcium deprivation by feeding them a calciumdeficient diet containing oxalate (Test group a), and in addition by subjecting them to pregnancy and lactation (Test group b).
The effect on the mandible of the present regimen was that of typical osteoporosis. Great amounts of bone tissue had been removed from the endosteal aspects of the bone, while the periosteal surfaces were almost intact, leaving the mandibular outline close to the normal. Alveolar bone loss did not seem exceptional when compared to the mandibular body. Bone resorption had occurred mostly on lamina dura. Horizontal bone loss was observed in a few cases where the gingival tissues were inflamed. The bone loss seemed to have been mediated by osteoclasts as well as mononuclear, hypertrophied, elongated cells, the former mostly in the alveolar process, the latter in the spongiosa and the endosteal cortical bone of the mandibular body. No signs of osteocytic osteolysis could be observed.     

Enamel hypoplasia in relation to caries in Guatemalan children.

Guatemalan children with anterior linear enamel hypoplasia (LEH) had a significantly greater caries experience in posterior dentition than their peers who did not have anterior LEH. The findings suggest that the synergistic mechanism of undernutrition and infection, which may underlie the occurrence of anterior LEH, may also predispose clinically normal appearing deciduous molars to an excessive caries attack equal to that observed in the grossly hypoplastic anterior teeth. The nutritional implications merit further investigation.     

Effects of criteria and checklists on reliability in preclinical evaluation

This study sought to expand and clarify research on intra- and interexaminer reliability in preclinical pedodontic grading. Six examiners graded 30 dentoform preparations using three different evaluation methods in a design that controlled the effects of order. The three methods were global (glance and grade), checklist with criteria (analytical), and checklist only. No method resulted in superior intra- or interexaminer reliability. The three evaluation methods can be easily adapted or replicated by other clinical disciplines, and the research design offers a model for similar studies in other preclinical and clinical dental settings.     

The effect of mineral trioxide aggregate on phagocytic activity and production of reactive oxygen, nitrogen species and arginase activity by M1 and M2 macrophages

AIM: To assess the influence of co-culture with mineral trioxide aggregate (MTA) on phagocytosis and the production of reactive oxygen intermediates (ROI) and nitrogen (NO) species and the arginase activity by M1 and M2 peritoneal macrophages. METHODOLOGY: Cellular viability, adherence and phagocytosis of Saccharomyces boulardii were assayed in the presence of MTA. Macrophages were stimulated with zymosan for ROI assays and with Fusobacterium nucleatum and Peptostreptococcus anaerobius and IFN-gamma for NO production and arginase activity, when in contact with capillaries containing MTA. Data were analysed by T, anova, Kruskall-Wallis and Mann-Whitney tests. RESULTS: M2 macrophages displayed greater cellular viability in polypropylene tubes, greater ability to ingest yeast and smaller production of ROI and higher arginase activity when compared with M1 macrophages. Both macrophages, M1 and M2, presented similar cell adherence and NO production. The addition of bacterial preparations to macrophages interfered with NO and arginase productions. MTA did not interfere with any of the parameters measured. CONCLUSIONS: Phagocytosis and the ability of the two macrophage subtypes to eliminate microbes were not affected by MTA.     

Attitudes of general dental practitioners in Europe to the microbial risk associated with dental unit water systems

Dental Unit Water Systems (DUWS) are used in dental practices to provide water for cooling of dental equipment and irrigation of the oral cavity. However, they have been demonstrated to be contaminated with micro-organisms. There are currently no European Union (EU) Commission guidelines for the microbial quality of water discharged by DUWS. This study was part of an EU research programme to investigate the microbial contamination of DUWS in general dental practice (GDP) in the UK, Denmark, Germany, The Netherlands, Ireland, Greece and Spain. OBJECTIVE: To undertake a questionnaire survey on the type of DUWS in use and determine the attitude of GDPs to the risk of microbial infection from DUWS. MATERIALS AND METHODS: The questionnaire was written and translated into the language of each country before being posted to each participating dentist. Dentists were asked to complete the questionnaire survey and return it by post. RESULTS AND CONCLUSIONS: The major findings were that the majority of dentists did not clean, disinfect or determine the microbial load of their DUWS, and that dentists would welcome regular monitoring and advice on maintaining their DUWS; the introduction of guidelines; and recommendations on controlling the microbial load of DUWS.     

A survey of undergraduate orthodontic training and orthodontic practices by general dental practitioners

PURPOSE of the STUDY: To assess satisfaction with undergraduate orthodontic training, the variety of treatments undertaken in general practice, practitioners' perceived competence in orthodontics and the level of interest in continuing education in orthodontics. DESIGN: Cross-sectional questionnaire-based study. MATERIALS and METHODS: A questionnaire was mailed to 520 general practitioners in Dublin, Kildare and Wicklow as listed in Irish Dental Council Register of Dentists 2003. RESULTS: Forty-six percent of dentists responded. More than half (54 per cent) of the respondents were satisfied with both academic and clinical aspects of undergraduate training. Twenty-nine percent regularly perform orthodontic treatment. Only 60 percent feel comfortable treating orthodontic emergencies. Over 70 percent have either already attended or aspire to attend further training in orthodontic diagnosis and interceptive orthodontics. CONCLUSIONS: Our study indicates that in the greater Dublin area, graduates (those qualified less than 10 years) are increasingly satisfied with undergraduate teaching. Orthodontic treatment is performed regularly in general dental practice with interceptive procedures most often carried out. While ability to deal with orthodontic emergencies is not universal, practitioners do appear confident to perform a variety of orthodontic procedures. Interest in continuing education in orthodontics is very high. Our study indicates that participation in continuing education in orthodontics appears to translate into greater provision of orthodontic care in general practice.     

In vitro susceptibility of Candida species to lysozyme

The in vitro sensitivity of 68 oral and vaginal isolates of Candida species to lysozyme was determined by a growth inhibition assay. Experiments with a single isolate of Candida albicans indicated that sensitivity to lysozyme increases in a concentration- and time-dependent manner. The examined Candida species were susceptible to lysozyme in the following decreasing order: Candida krusei (most susceptible), Candida parapsilosis, Candida tropicalis, Candida guilliermondii, Candida albicans and Candida glabrata. However, there were differences in susceptibility to lysozyme among different isolates within a given species. These results indicate that lysozyme may regulate, in a qualitative and quantitative manner, the yeast populations on human mucosal surfaces.