Dental caries experience and defects of dental enamel among 12-year-old children in north London, Edinburgh, Glasgow and Dublin.

A multi-center study of caries experience and defects of dental enamel was conducted among 12-yr-old children in north London, Edinburgh, Glasgow and Dublin. None of the cities had water fluoridation except Dublin, which was included in the national program introduced in the Republic of Ireland in 1964. A random sample of children was drawn from state schools in each location and identical methods of clinical examination were used throughout under the same standardized conditions.

Killing of cariogenic bacteria by light from a gallium aluminium arsenide diode laser.

Suspensions of Streptococcus mutans, S. sobrinus, Lactobacillus casei and Actinomyces viscosus were exposed to light from a gallium aluminium arsenide laser in the presence of aluminium disulphonated phthalocyanine and the numbers of survivors determined. Exposure to the laser light in the absence of the dye, or the dye in the absence of the laser light, had no significant effect on the viability of the organisms.

Dimensional stability of denture bases following repair with microwave resin.

The dimensional stability of a commercially available acrylic resin, designed specifically for polymerization by microwave irradiation, was compared with that of a conventional water-bath-cured resin. Resin bases were processed on duplicate stone casts prepared from a cobalt chromium master die. Twenty bases were polymerized, using acrylic resin modified for rapid heat curing, in a water-bath at 100 degrees C for 22 min.

Enamel opacities and dental caries in children who used a low fluoride toothpaste between 2 and 5 years of age.

A recent clinical trial investigated the cariostatic effectiveness of a low (550 ppm) fluoride toothpaste in comparison with a standard (1050 ppm) control paste in pre-school children who were 2-years-old at the start of the 3-year trial. The present study has investigated the prevalence of enamel opacities in permanent incisor teeth and of caries in children who had taken part. As well as children from test and control groups, a third group of non-trial children were included in the sample.

An in-vitro evaluation of the influence of canal curvature on the sealing ability of Thermafil.

The sealing ability of lateral condensation and Thermafil were compared in root canals with curvatures either greater or less than 25 degrees. Forty-eight canals in roots of extracted human mandibular molar teeth were divided into four groups of 12. The root canals in two groups had curvatures of less than 25 degrees and the remaining two groups had canals with curvatures greater than 25 degrees.

A survey of current practice into the use of aesthetic inlays.

In recent years there has been a concerted effort to produce an aesthetic restoration to replace amalgam, while retaining its qualities of strength and longevity. The use of porcelains and composite resins used indirectly as inlays and onlays has today improved the qualities of directly filled composites. A survey of 310 general dental practitioners in the UK known to use this type of restoration produced 162 responses to a questionnaire to evaluate their experiences to these techniques.

Properties of acrylic resins incorporating 4META for bonding to cobalt-chromium alloys.

Polymer substitution into proprietary 4-methacryloxyethyltrimellitate anhydride (4META) resins creates tooth coloured veneers for cobalt-chromium overlay dentures. The elastic moduli and shear-bond strengths of proprietary resins (matched) and resins polymerised from 4META monomers and substituted polymers (unmatched) were determined. Bond strengths were similar for matched and unmatched heat curing resins (mean 14.

The influence on partial denture design of a teaching video for general dental practitioners.

This evaluation was based on replies from a random sample of general dental practitioners who were asked to complete questionnaires before and after being sent a video and accompanying booklet on partial denture design. Forty per cent (257) of the original sample (636) completed and returned both questionnaires. A total of 212 respondents (82%) felt the video had been of value and 175 (68%) said they would be more likely to provide metal partial dentures after having watched it.

Bactericidal effect of laser light and its potential use in the treatment of plaque-related diseases.

Chemical antibacterial agents are increasingly being used in prophylactic and therapeutic regimes for plaque-related diseases. As these agents can be rendered ineffective by the development of resistance in the target organisms there is a need to develop alternative antimicrobial approaches. Light from high-power lasers is known to be bactericidal and investigations have shown that it is effective against organisms implicated in caries and inflammatory periodontal diseases.

Complications and maintenance requirements for fixed prostheses and overdentures in the edentulous mandible: a 5-year report.

Overdentures and fixed prostheses were consecutively placed into 50 edentulous mandibles and were followed for 5 years. During this period of follow-up, 25 overdentures were supported by 68 implants with a success rate of 92.65%, and 25 fixed restorations were supported by 132 implants with a success rate of 90.

Review of a new root canal obturation technique.

The relatively new technique of obturation using Thermafil endodontic obturators is claimed by the manufacturers to use gutta percha of a more linear structure than conventional gutta percha, and so provide a seal at least equal to laterally condensed material. In this article the authors describe the practical use of this widely marketed technique. Studies which have so far evaluated this technique are reviewed and its advantages and shortcomings discussed.

An unusual vascular hamartoma on the gingiva of an 11-year-old boy.

A case is reported of an unusual vascular lesion on the gingiva of an 11-year-old boy which clinically and histopathologically did not fit well into any current classification of vascular lesions. The lesion presented as a firm nodular swelling of the buccal and lingual gingiva which had been present for 9 years. The term endovascular papillary haemangioma is suggested.

Lethal photosensitisation of Staphylococcus aureus.

The purpose of this study was to determine whether toluidine blue O (TBO) could sensitise Staphylococcus aureus to killing by light from a low-power helium/neon (HeNe) laser. Suspensions of the organism were irradiated with light from a HeNe laser in the presence and absence of TBO and the survivors enumerated. A 95% reduction (9 x 10(7) cfu) in the viable count was achieved following irradiation with 0.

An in-vitro evaluation of the influence of temperature of plasticization on the sealing ability of Thermafil.

The effect of temperature of plasticization on the sealing ability of Thermafil obturators was evaluated. Forty-eight canals in roots of extracted human mandibular molar teeth were divided into four groups of 12. The root canals had curvatures of less than 25 degrees, as determined using the Schneider technique.

Dimensional changes occurring in a glass-ionomer cement.

The dimensional changes occurring when glass ionomer cements are exposed both to desiccating and moist conditions were investigated. All work was done at 23 degrees C. The effect of time allowed for cements to mature before exposure to the test conditions was studied as was the effect of adding cellulose ethers.

In vitro cleaning ability of root canal irrigants with and without endosonics.

A variety of methods have been used to evaluate the cleanliness of root canals after endodontic preparation and irrigation. Few irrigation agents other than sodium hypochlorite (NaOCl) have been tested in conjunction with endosonics. The purpose of this study was to examine the cleaning ability of water, NaOCl, Hibiscrub and a biological washing liquid when used as intracanal irrigants, with and without endosonics.

Factors influencing the success of conventional root canal therapy--a five-year retrospective study.

This retrospective study on the outcome of conventional root canal therapy was carried out on patients attending the Eastman Dental Hospital between 1970 and 1982. A minimum follow-up period of 5 years was required for patients to be included in the survey. The characteristics of the resulting sample group, the techniques for canal preparation and obturation and the obturating materials used were analysed.

E-cadherin expression in normal, hyperplastic and malignant oral epithelium.

E-cadherin is a calcium-dependent cell adhesion molecule which is important in cell-cell interactions in epithelium and plays a major role in maintaining the structure and integrity of epithelial sheets. The purpose of this study was to examine E-cadherin expression in normal and malignant oral epithelium. Ten specimens of normal oral epithelium, five specimens of hyperplastic epithelium and 15 squamous cell carcinomas were stained using a standard immunoperoxidase technique and a monoclonal antibody to E-cadherin.

Ultrastructural finding of vascular degeneration in myositis ossificans circumscripta (fibrodysplasia ossificans).

A case of myositis ossificans circumscripta (fibrodysplasia ossificans) of the masseter muscle has been studied ultrastructurally. It showed atrophy of muscle fibres with deranged myofilaments, adjacent to dense fibrous tissue, osteoid and bone. A large number of the cells found in the dense fibrous tissue showed vacuolation and separation of membrane bound vesicles similar to matrix vesicles released by chondroblasts and osteoblasts during calcification.

Sensitisation of Candida albicans to killing by low-power laser light.

The purpose of this study was to determine whether Candida albicans, and other Candida spp. responsible for HIV-associated candidosis, could be sensitised to killing by low-power laser light. Suspensions of C.

Non-infectious diseases of the oral soft tissue: a new approach.

A significant proportion of the non-infectious diseases of oral mucosa are either auto-immune in nature or have lesions which are the result of immunologically-mediated events. These include pemphigus, benign mucous membrane pemphigoid, linear IgA bullous dermatosis, dermatitis herpetiformis, epidermolysis bullosa acquisita, erythema multiforme, and lichen planus. Although each of these has certain specific characteristics, all may produce bullae, erosions, and ulcers on the oral mucosa, resulting in confusingly similar clinical presentations.

Soft tissue chondroma of the cheek.

Soft tissue chondromas are rare benign tumours unrelated to bone that arise primarily in the distal extremities. Lesions in the soft tissues of the oral cavity are extremely rare although several chondromatous lesions have been reported in the tongue. A case is presented of a chondroma arising in the buccal mucosa.