Sensitization of oral bacteria in biofilms to killing by light from a low-power laser.

Biofilms of Streptococcus sanguis, Porphyromonas gingivalis, Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans were prepared on the surfaces of agar plates and a number of compounds were screened for their ability to sensitize bacteria in these biofilms to killing by light from a 7.3 mW Helium/Neon (He/Ne) laser. Toluidine blue O and methylene blue enabled detectable killing of all four target organisms after exposure to He/Ne light for 30 s.

A comparison in vitro of two ultrasonic root canal preparation techniques.

Two ultrasonic techniques were compared for their ability to clean and shape root canals in extracted human teeth. One technique was recommended by the manufacturer (Cavi-Endo, Dentsply), while the other was a modification by the authors of the stepdown technique. Mesiobuccal root canals of molars were instrumented using these techniques, after which a silicone impression material was injected into the prepared canals.

Drugs used in the management of trigeminal neuralgia.

Management of trigeminal neuralgia, a severe facial pain, remains difficult. All patients are initially treated with drugs. Since the seventeenth century more than 40 different preparations have been used; some of these, although effective, had toxic side effects.

A preliminary evaluation of the use of a redox agent in the treatment of chronic periodontitis.

A small-scale clinical trial was carried out to evaluate the effect of a redox agent, methylene blue, on microbiological and clinical indices of chronic periodontitis. Methylene blue was applied subgingivally on a daily basis for 7 d to 25 test sites in 7 patients and the sites evaluated clinically and microbiologically for up to 14 d: 25 control sites in the same patients received sterile water. The test sites showed statistically significant differences from the control sites in terms of changes in a number of clinical and microbiological indices.

Initial studies on the behavior of salivary proteins at liquid/air interfaces.

The mode of adsorption of salivary proteins at air/liquid interfaces was studied by using the drop volume technique to measure the kinetics of surface tension decay of aqueous salivary solutions. Adsorption of salivary proteins from whole saliva was fast, with a plateau value of the surface tension of 43 (+/- 2) mNm-1. As the concentration of saliva was reduced, the plateau value of surface tension increased and was achieved more slowly.

Sensitization of oral bacteria to killing by low-power laser radiation.

Twenty-seven compounds were screened for their ability to sensitize Streptococcus sanguis to killing by light from a 7.3-mW Helium/Neon (HeNe) laser. Bacteria were mixed with various concentrations of the test compounds, spread over the surfaces of agar plates, and then exposed to light from the HeNe laser for various time periods.

The clinical use of glass-ionomer cements.

The use of glass-ionomer cements in clinical dentistry has expanded greatly over the last decade. Their use in treating early carious or erosion lesions has been investigated widely and established techniques include fissure filling, restoration of erosion lesions without cavity preparation, and the internal or tunnel restoration. Because of their adhesion to moist tooth structure, biologic compatibility, and fluoride release, increasing use also has been made of their anticariogenic properties in treating geriatric patients.

Indelible bond location marks: an avoidable aesthetic hazard.

An increasingly popular method of aiding the precise placement of bonded brackets is to identify the long axis and centre of the crown with small pencil marks. A case is reported where marks placed with a soft pencil in the centre of the etched enamel have led to the inclusion of pigment deep in the enamel surface which has proved impossible to remove.

A comparison between the old Transcend and the new Transcend series 2000 bracket.

The shear/peel and tensile/peel bond strengths of the original Transcend and the new Transcend series 2000 bracket were determined using two different light-cured composites, Prismafil (high filler) and Heliosit (low filler). Predominant sites of failure were recorded for each bracket with each cement in each mode of testing. Transcend series 2000 produced higher bond strengths than Transcend in shear/peel, but were significantly weaker in tensile/peel testing.

The comparative strengths of commercial glass-ionomer cements with and without metal additions.

Metal reinforced glass-ionomer cements are said to possess superior mechanical properties when compared to non-metal reinforced glass-ionomer cements. However, the literature to date does not always support this view, owing to the variety of materials and test methods employed. In this study the mechanical properties of three reinforced and three standard materials were tested using the standard specification tests of compressive and diametral strength in addition to tensile strength using the four point bend test.

In vitro bond strengths of three current dentin adhesives to primary and permanent teeth.

The in vitro shear bond strengths of three chemically different dentin bonding agents were tested between both permanent and deciduous dentin and their respective anterior composite filling materials. The effect of the post-mortem age of the teeth on bond strength was evaluated by comparison of fresh (extracted within 24 h) and old (extracted within 10 d) teeth. The results indicated that these materials bonded more strongly to the dentin of permanent than to deciduous teeth (8.

Diagnostic dilemma: an unusual presentation of an infected nasopalatine duct cyst.

The pertinent literature on nasopalatine duct cysts is reviewed. A case is reported in which a nasopalatine duct cyst infected by Actinomyces presented clinically with unusual features. The clinical findings could have been confused with an early acute periapical abscess arising from an incisor tooth.

The nature of the eosinophilic and laminated masses in the adenomatoid odontogenic tumor: a histochemical and ultrastructural study.

The eosinophilic and laminated masses in AOT were investigated with the light and electron microscope in two cases. The results showed that the eosinophilic amorphous masses were heterogenous and consisted mainly of three types of fibrils. These were: thin collagen, electron dense fibrils probably resulting from degradation of collagen and masses of amyloid filaments with or without collagen fibers in normal and degraded forms.

The effect of adhesive type and thickness on bond strength of orthodontic brackets.

Fine-mesh based brackets were bonded to plastic cylinders using four different adhesives. Adhesive thickness was controlled using a bonding jig. The bond was then tested to failure using a shear force.

In vitro erosion of 20 commercial glass ionomer cements measured using the lactic acid jet test.

The lactic acid jet test has been proposed for incorporation in international standards for dental cements, since results correlate well with in vivo erosion. In the literature, jet test results have been reported on only six glass ionomer cements. This study examines three types of glass ionomer, restorative, luting and metal reinforced, twenty materials from six manufacturers.

The status of bite-wing radiographs in enhancing discriminatory ability in caries prophylactic clinical trials.

Data were taken from six randomised controlled trials of caries prophylactic agents in order to investigate the capacity of bite-wing radiographs of posterior approximal tooth surfaces to enhance discrimination between test and control group measurements. The findings showed that, where an active control agent was employed, the addition of radiographic to clinical examination data failed to improve discriminatory power in comparisons between 3-year caries increments.

A questionnaire survey of attitudes and concerns of three professional groups involved in the cleft palate team.

This study investigated the opinions of three of the professional groups who treat cleft lip and palate patients in the United Kingdom. Plastic surgeons, orthodontists, and speech therapists were asked to give their opinions regarding adolescents with a unilateral cleft of the lip and palate. A mail questionnaire investigating four main areas: treatment, facial appearance and speech, social and emotional aspects, and the perceived success of the specialists was sent to each subject.

Mycoplasmas in the plaque and saliva of children.

Plaque and saliva samples from 60 children were screened for the presence of mycoplasmas. Each child provided a sample of stimulated saliva and one of plaque from the buccal surface of the most posterior tooth in the upper right quadrant. Mycoplasmas were cultured from 93% of the saliva samples and from 50% of the plaque samples.

Clinical applications of glass-ionomer cements.

The use of glass-ionomer cements in clinical dentistry is now well established. They have a number of unique properties, including adhesion to moist tooth structure, biological compatibility, and anticariogenic properties due to their fluoride release. Their use in treating early carious or erosion lesions has been widely investigated.

Elevated IgA salivary antibody levels to mycobacterial 65 kDa stress protein in patients with oral candidosis.

Salivary IgA antibody levels to cytoplasmic protein extract of Candida albicans (CSE) and to mycobacterial 65 kDa stress protein (mSP65) were determined by ELISA in 25 patients with chronic atrophic oral candidosis and in 23 controls with clinically healthy oral mucosa. The results showed significantly elevated anti-CSE and anti-mSP65 antibody levels in patients when compared with healthy controls (P < 0.001).