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This study determined the mechanical properties of 19 dental floss holders. Eight single-use holders and 11 reusable ones were tested. An in vitro model with dental proximal contact strength of 8 N was created. Every device had to pass the proximal contact 30 times. We measured (1) the displacement of the floss [mm], (2) the force [N] necessary to pass the proximal contact after the 30th passage, (3) the loosening of the floss (offset [mm]), and (4) the change in the distance between the branches [mm]. Each measurement was repeated seven times. The results are displacement of the floss after 30 passages, 2.0 to 9.2 mm; passage force, 2.6 to 11 N; increases in branch distance, 0-2.9 mm; offset of the floss, 0-1.8 mm (all numbers are medians). Based on cleaning a full dentition (30 passages), we suggest introducing minimal requirements of <4 mm for the displacement of the floss, ≥11 N for the force, and <0.1 mm for the difference in branch distance and the offset. Only two products fulfilled our criteria. The tests show that dental floss holders vary extremely in their mechanical properties. Their effective use seems often impossible due to limited mechanical properties.

The goal of this in vitro study was to identify the most suitable dye for endodontic dye leakage studies, which could be a further step towards standardisation. The root canals of 70 extracted, single-rooted human adult teeth were enlarged to apical size 50 using hand instruments. The teeth were divided into seven groups (n = 10 each), and all root canals were completely filled by injection with one of the following dyes: methylene blue 0.5% and 5%, blue ink, black ink, eosin 5%, basic fuchsin 0.5% and drawing ink. Transverse root sections from the coronal, middle and apical part of the roots were examined, and the percentage of the dentine penetrated by dye was evaluated by software-supported light microscopy. In addition, the range of particle size of drawing ink particles was evaluated. There were conspicuous differences in the relative dye penetration into the root dentine and the penetration behaviour in the different root sections (two-way ANOVA, both p < 0.0001). One dye (drawing ink) penetrated less into the root dentine compared with all the others (p <0.0001). The particle size of this agent (0.1-2 microm) corresponds best with the size range of a representative selection of 21 species of pathogenic endodontic bacteria. Compared to the other dyes tested, drawing ink appears to be superior for use in endodontic dye leakage studies. The penetration behaviour into the root dentine of all the other dyes tested might be one factor that limits the applicability of these dyes in dye leakage studies.

Background: Toothache prevalence in the overall population is considerable. However, for clinical purposes, the classification schemes available do not appear to be sufficiently sophisticated. Moreover, not all known forms of dental pain are considered. A refined classification that meets current standards is therefore introduced. To facilitate diagnosis, the characteristic features of the various types of odontalgia are summarized., Results: The new classification differentiates among seven different origins of pain: 1. dentinal pain (originating from the pulpal tissues), 2. pulpal pain (originating from the pulpal tissues), 3. periodontal pain, 4. alveolar-osseous pain, 5. atypical odontalgia, 6. heterotopic dental pain, 7. odontalgia associated with primary psychosocial factors., Conclusions: In our opinion, the proposed classification differentiates among the different forms of odontalgia more precisely than all previous ones. However, its viability and advantages over other available classification schemes still need to be verified in daily practice.

Unfilled resins are commonly in use as sealant material. In addition, there are filled sealants available. Helioseal F is a newly developed filled material with fluoride release. In this clinical trial, Helioseal F has been evaluated in one lower molar versus Delton opaque as an unfilled control in lower molars. After 12 months there were no significant differences in retention, porosities, and the number of clinically unacceptable margins between the materials. The complete retention was 30 out of 31 examined teeth for Delton and 28 out of 31 for Helioseal F. After 1 year of clinical testing, these results indicate that a sealant containing fluoride-releasing particles did not show a significant difference in retention rate compared to an unfilled conventional sealant. However, long-term results concerning marginal adaptation should be evaluated.

Amalgam, which has long been used as a restorative material, has recently become the target of more and more criticism. An assessment of amalgam requires consideration of different aspects of toxicology, allergology, electrochemistry, psychology, and dentistry. Up to now, there is no scientific evidence that the physical properties of amalgam can lead to pain. Amalgam fillings with insufficiently formed chewing surfaces can cause myofacial pain, but the same can be said of restorations performed with any other material. Almost all preventive or therapeutic dental treatment can have adverse effects, and an attempt to eliminate all risks could well eliminate established methods in dentistry as well. This paper presents the ramifications of an amalgam ban, which is being called for by various groups, in some detail.