Comparison between two Procion dyes and Alizarin Red to assess marginal leakage in resin restorations. A laboratory study

To assess the width of the gaps that may occur in resin restorations bonded to dentine, buccal and lingual cavities were prepared in 18 caries- and restoration-free extracted molar teeth. All teeth were restored with composite resin. Nine of the teeth were then thermocycled for five hours. All teeth were stained with 0.5 per cent, 1.0 per cent or 1.5 per cent solutions of chloro-s-triazinyl dyes (Reactive Red and Reactive Orange 14) or Alizarin Red in order to assess the effectiveness of each stain in detecting marginal leakage. Quantitative assessment indicated that Reactive Orange 14 was superior to the other two stains as it more clearly defined the marginal gaps of the restorations. This superiority was evident for both thermocycled and nonthermocycled teeth.     

Cephalometric errors: A comparison between repeat measurements and retaken radiographs

This study compares landmark location errors in cephalometric radiography (when re-measuring radiographs) and radiographic errors (when retaking the radiograph). The samples comprised 32 remeasured and re-digitized radiographs and a further series of 22 retaken radiographs drawn from the same overall sample of 12-year-old Chinese children in Hong Kong. All radiographs were recorded in natural head posture with the lips in light contact. The relative size of the errors were assessed by calculating the 'error percentage' for both selected dento-skeletal and soft tissue profile measures. It is suggested that this index is clinically more meaningful than the usually used 'method error'. It expresses the variance of the method error (me2) as a percentage of the variance of the measurement under study (standard deviation2). This error percentage was found to be doubled, on average, for measurements on the retaken radiographs. In general, measures with most landmarks in the mid-sagittal plane showed the least increase in percentage error. The results suggest that errors arising from retaking cephalometric radiographs may effectively be greater than those usually reported. The Frankfort plane, the functional occlusal plane and the incisor long axes displayed poor reproducibility. For the soft tissues the lips served as poor angular landmarks and relatively acute angles with short 'arms' also displayed large errors.     

Water Fluoridation: a Response to Critics in Australia and New Zealand

Recent questions about the effectiveness of water fluoridation have come from Diesendorf in Australia and Colquhoun in New Zealand. This report examines the arguments of both authors in detail and finds errors in each. Diesendorf employed an outdated view of how fluoride exerts its anticariogenic action and took a number of quotations out of context. Colquhoun's data are questionable. Neither author has produced evidence to challenge the established safety and effectiveness of water fluoridation.     

Response Trends and Nonresponse Bias in a Mail Survey of Oral and Facial Pain

While mail surveys offer a low-cost method for collecting health data, they have been unpopular because of concerns about low response rates and nonresponse bias. This paper examines the response to a mail survey concerning oral and facial pain and uses regression techniques to assess the degree and direction of nonresponse bias on estimated prevalence rates. The analysis shows that early and late responders to the survey differed in terms of sociodemographic variables and responses to items concerning pain. The regression analysis suggests that the rather high prevalence rates revealed by the survey are not a product of bias induced by nonresponse and deserve further investigation.     

Dispensing and weighing apparatus for alginate impression material

Constant proportions in mixing of alginate impression material are difficult to achieve, especially in a teaching department, owing to variability in powder measurement with the conventional scoop method. Apparatus to facilitate powder measurement by weighing is described, and its accuracy assessed.     

Dental Utilization by Low-income Mothers

Objective : This study examines the influence of predisposing, enabling, and need variables on whether low-income mothers sought dental care during the past year. This report is a substudy of mothers and children on their self-reported health status, utilization, access, and satisfaction with health care in general. Methods : A convenience sample of 502 mothers and youngest child younger than 6 years old was administered a face-to-face questionnaire in four Ohio counties. Information was collected at county human services offices and WIC clinics between November 1995 and July 1996. Using whether or not the mother sought dental care as the dependent variable, logistic regression models were created for the variables within the predisposing, enabling, and need characteristics separately and together. Results : Fewer than one-half of the mothers sought dental care during the past year. Variables associated with the predisposing characteristic explained little about who sought care. Those mothers who have Medicaid coverage are 2.7 times more likely to have a dental visit than those without insurance. Moreover, those mothers who perceive any dental need are several times less likely to have received dental care than those who have no perceived need. Conclusion : Even among a somewhat homogeneous population of low-income women, source of payment for dental services and perceived need for dental care are discriminating variables in determining who seeks dental care.     

Gingival crevicular fluid lactoferrin levels in adult per iodontitis patients

The present study was designed to determine in a cross-sectional study whether there was any relationship between the levels of lactoferrin in gingival crevicular fluid and clinical periodontal parameters. Crevicular fluid was collected from individual sites using standardized filter paper strips (clinically healthy sites, N=23; periodontitis sites, n=66) and evaluated for lactoferrin by enzyme-linked immunosorbent assay. The data showed that: (1) the total amounts of lactoferrin were 0.003-0.021 ng (30 second sample) (average 0.009±0.005 ng) in a clinically healthy periodontium group and 0.016-3.847 ng (30 second sample) (average 0.575±0.069 ng) in adult periodontitis patients (statistically significantly higher in adult periodontitis patients); and (2) the total amounts of lactoferrin were significantly correlated with clinical parameters,     

Radionuclide skeletal imaging and single photon emission computed tomography in suspected internal derangements of the temporomandibular joint

Fifty one subjects who had pain involving the temporomandibular joint were evaluated using multidirectional tomography, arthrography, conventional nuclear scanning, and single photon emission computed tomography (SPECT) to assess the association of arthritis of the temporomandibular joint with internal derangements related to meniscal dysfunction. Five (56%) of the nine subjects who had normal arthrograms and normal multidirectional tomograms had SPECT scans that were positive for osseous changes. Twenty-two subjects (27 temporomandibular joints) were diagnosed by arthrography to have meniscal displacement with reduction. Multidirectional tomograms of the 27 joints were positive for osseous changes in five (18%) joints, whereas SPECT scans were positive in nine (70%) joints. Twenty subjects (20 temporomandibular joints) had an arthrographic diagnosis of meniscal displacement without reduction. Multidirectional tomograms of the 20 joints were positive for osseous changes in 14 (70%) joints, and SPECT scans were positive in 16 (80%) joints (P less than 0.001 vs control group). Initial observations with SPECT indicate it is a promising imaging method for detecting and staging osseous disease of the TMJ related to meniscal dysfunction.     

The use of fibrin adhesive in sinus lift procedures

Sinus lift bone grafting has expanded the use of dental implants in reconstructions of the atrophic maxilla. Potential problems include sinus membrane tear, which can lead to graft infection and early failure. Attempts at managing sinus membrane perforations are often limited by difficulty of access, as well as by the friability of the soft tissue lining the sinus. Various techniques have been proposed for managing such membrane tears. The use of fibrin adhesive, however, may present a potential solution in such situations. This article reports our experience with the use of fibrin adhesive in sinus lift procedures, as well as on its autologous preparation.