[Evaluation of amalgam separators]. / Une évaluation des séparateurs d'amalgame.

There is an increased awareness about environmental protection and reduction of toxic waste. This applies also to the dental profession. One of the main concerns in dentistry is the reduction of amalgam slurry, which contains mercury, being drained by dental plants. The largest pieces of amalgam are stopped by the coarse filter. For eliminating the amalgam silt out of the sewage, amalgam separators have been developed. This paper presents an evaluation of seven separators, mounted in a preclinic set-up. The average particle size of the amalgam waste was determined. The flow-velocity of the separators differed very much between the different separators. One apparatus produced an inferior separation capacity compared to the others. Apparently not one was capable to purify the effluent to 0.05 mg/l during peak supplies of amalgam slurry. Other measures such as the reduction of the need for restoring, the use of alternative materials and modified preparation techniques, will further reduce the drain of amalgam silt by dental installations.

Comparison in shear bond strength of orthodontic brackets between five bonding systems related to different etching times: an in vitro study.

New adhesives are continuously being marketed. The adhesive-bracket bond is still the weakest point in orthodontic bonding. A new device for the measurement of shear bond strength values (SBS) of orthodontic brackets is presented in this article. With this device, five commercial products were evaluated for their SBS: Lee Bond (LB), Concise (C), Super C (SC), Achieve-no-mix (ANM), and Panavia Ex (PE). After applying Begg brackets of laminated minimesh on lower human incisors, the specimens were thermocycled. The products investigated produced high bond strengths. The products tested showed shear bond strengths that were significantly lower than those stained with PE. The application of PE yielded the highest shear values. Nevertheless, some characteristics of this product might be clinically somewhat inconvenient. There was no significant difference in shear bond strength between 15 and 60 seconds enamel etching before bond application.

[Determination of tooth length in endodontics]. / La détermination de la longueur en endodontie.

Determination of the exact tooth length and subsequent working length remains a corner stone of proper endodontic treatment. Up to now, no system has proven to provide the exact location of the apical constriction under all circumstances. Several possibilities of determining tooth length are discussed. Factors influencing the outcome of the different techniques are described. A simple and rather accurate way for calculating tooth length on X-rays is elaborated. Apparently, electronic devices are becoming increasingly accurate, and may become a challenge for the radiographic tooth length determination. Actually, dentists have most of all to rely on X-rays for tooth length determination.

Effect of anti-sensitive toothpastes on opened dentinal tubules and on two dentin-bonded resins.

Treatment of dentin hypersensitivity will become of increasing importance in the daily practice of dentistry. The goal of any therapy should be the closure of opened dentinal tubules. The present study made an SEM evaluation of the effect of anti-sensitive toothpastes on root dentin with regard to the superficial changes and possible penetration by toothpaste particles. Further, the study performed an evaluation of the wear-resistance of two dentin-bonded resins during brushing, using the same anti-sensitive toothpastes. Having induced coverage of the dentinal tubules with the toothpastes (Sensodyne, Emoform and Macleans Sensitive), no particles were found within the tubules. The application of dentin-bonded resins seems an alternative solution for treating dentin hypersensitivity.

The preventive Class II restoration: clinical application.

A renewed interest in conservative cavity preparations has emerged in recent years. In this paper, a substance-saving cavity preparation for the treatment of small, interproximal carious lesions, the preventive Class II preparation, is presented. The indications, the cavity preparation, and the obturation are discussed. The combined use of both amalgam and a light-curing pit and fissure sealant is suggested. Clinically, this type of restoration seems to be acceptable. Nevertheless, more clinical experience and in vitro research regarding this type of restoration is needed.

A decision tree for the treatment of caries in posterior teeth.

Because of a better understanding of the caries process, a decrease in the prevalence of caries, and the rapid development of dental materials, a renewed approach to the treatment of dental caries in the posterior region is possible. A decision tree for the treatment of caries in posterior teeth, taking into account some of the most recent tooth substance-saving treatment options, is presented. These possibilities gradually evolve from nondestructive to conventional cavity preparations. In addition, the "preventive Class II restoration" is introduced. The application of this conservative attitude toward invasive techniques offers great advantages for both the patient and the dentist. Unfortunately, this approach is time-consuming. Long-term clinical evaluation of the application of the proposed decision tree on a wide scale is needed to confirm its potential benefits or to modify and improve treatment options.

A scanning electron microscopic and tensile bond strength evaluation of Gluma dentin bond application, as a function of dentinal pretreatment.

Scanning Electron Micrographs (SEM) and Tensile Bond Strength (TBS) measurements were used to evaluate the influence of three different dentinal pretreatments. A new testing device was developed for the TBS measurements. Human tooth roots were ground with a diamond bur. Tap water, Gluma Cleanser, and Neo-Sabenyl-Tubulicid were used to clean the surfaces before SEM inspection. The adhesion between root dentin and Lumifor Composite restorations was mediated by Gluma Bond. SEM observations revealed that a 30-second application of Gluma Cleanser removes the smear layer totally. Neo-Sabenyl-Tubulicid produced a very smooth surface. Application of Gluma Bond did not alter this appearance. Mean TBS values for surfaces sprayed with tap water, Gluma Cleanser, and Neo-Sabenyl-Tubulicid were 10 MPa, 7.3 MPa, and 10 MPa, respectively. There was a significant difference between group 2 (Gluma Cleanser) and the other groups. From this in vitro study, it is concluded that total removal of the smear layer with opening of the dentinal tubules (e.g., by means of Gluma Cleanser) reduces the TBS of Gluma Dentin Bond-Lumifor restorations to ground root dentin.

Root surface caries: an update.

Root surface caries lesions will become more predominant in the future. Recently, several definitions and graduations have been suggested. Objective, epidemiologic data are still lacking. The etiologic factors of root surface caries generally are parallel to those of coronal caries. However, some nuances needed to be identified. Differences concerning the bacteriologic characteristics, the substrate, the mineral composition, and the clearance are discussed. Some patients are more likely to develop multiple lesions than others. Restorative materials with bonding abilities to dentin are the preferred materials. Fluoride applications will probably be the most effective in preventing the development of root surface caries lesions.

A clinical evaluation of a light-cured fissure sealant (Helioseal).

The clinical success of pit and fissure sealants has been reported by several authors. In this study a white-shaded, visible-light-cured sealant was used; the results of the clinical evaluation confirmed this finding. Concerning retention rate, marginal adaptation, and the presence of secondary caries and air bubbles, good results were obtained. Data indicate that a visible- light-cured sealant (Helioseal) appears to be as good as the self-cured sealants and better than the UV-light-cured products. A comparison was also made between the invasive (PFSI) and non-invasive (PFS) application techniques; with respect to the marginal adaptation and the presence of air bubbles, better results were found for fissures that had been enlarged as a preventive measure. More longitudinal studies over a longer period of time are necessary.

[Avulsed teeth. A case study]. / La dent avulsée. Une étude de cas.

A clinical case of exarticulation and replantation served to discuss recent insights regarding the treatment of total avulsions of permanent teeth. A flow chart representing all treatment options is given. The tooth has been replanted in near ideal conditions; within one hour after the avulsion, the young patient attended the dental school with his avulsed tooth stored in milk. After replantation, a very simple splint was applied for only a fortnight and a provisory endodontic therapy with calcium hydroxide was performed. Adequate oral hygiene measures supported with chlorhexidine gel were instructed. These promote the healing process and ultimately also contribute to a long-term survival of the replanted tooth. After healing, a permanent root canal filling was applied and the crown was restored by means of composite material. The one-year- follow up check did not show any sign of resorption and/or ankylosis.

A complete fusion in the primary human dentition: a histological approach.

A trace of cementum totally surrounded by dentine could not be found here; this histological evaluation gave no further information about the origin of this double tooth. The fact that the dental pulp was complex could not be observed radiographically.