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Mechanical root reinforcement is an important parameter to evaluate for stability analysis of rooted slopes. The contribution of roots is however difficult to quantify in situ without time-consuming methods or heavy equipment. Here we report field testing using the newly developed 'corkscrew' method at two different sites with plantings of conifers and blackcurrant. In both sites we found positive correlations between root quantity and root reinforcement in surface layers where many roots were found. Below 125 mm depth, no correlations could be found, probably due to variability in soil stress and gravel content. Roots were shown not only to increase the soil peak strength, but also to add ductility to the soil, i.e., adding strength over much larger displacement ranges. Measured reinforcement, although similar to other experimental studies, was smaller than predicted using existing models. This may be attributed to the distinct difference in shear displacement required to mobilize the strength of rooted soil as compared with fallow soil. At displacements sufficient to mobilize root strength, the soil strength component has reduced from peak to a much smaller residual strength. The corkscrew method proved a promising tool to quantify root reinforcement in field conditions due to its ease of use and short test duration. Key words: root reinforcement, cork screw, vegetation, in situ testing, slope stability. Le renforcement mecanique des racines est un parametre important a evaluer pour l'analyse de la stabilite des pentes enracinees. La contribution des racines est cependant difficile a quantifier in situ sans des methodes qui prennent du temps ou de l'equipement lourd. Nous rapportons ici des essais sur le terrain en utilisant la nouvelle methode, appelee <>, et developpee sur deux sites differents avec des plantes avec des coniferes et du cassis. Dans les deux sites, nous avons trouve des correlations positives entre la quantite de racines et le renforcement des racines dans les couches de surface ou de nombreuses racines ont ete trouvees. Au-dessous de 125 mm de profondeur, aucune correlation n'a pu etre trouvee, probablement en raison de la variabilite du stress du sol et de la teneur de gravier. Les racines ont ete montrees non seulement pour augmenter la resistance maximale du sol, mais aussi pour ajouter de la ductilite au sol, c'est-a-dire ajouter de la resistance sur des plages de deplacement beaucoup plus grandes. Le renforcement mesure, bien que similaire a d'autres etudes experimentales, etait plus petit que prevu, en utilisant des modeles existants. Cela peut etre attribue a la difference nette de deplacement de cisaillement necessaire pour mobiliser la resistance du sol enracine par rapport au sol inexploite. Aux deplacements suffisants pour mobiliser la force des racines, la resistance du sol a ete reduite du maximum a une resistance residuelle beaucoup plus faible. La methode tire-bouchon a demontre un outil prometteur pour quantifier le renforcement des racines dans les conditions du terrain, en raison de sa facilite d'utilisation et de sa courte duree d'essai. [Traduit par la Redaction] Mots-cles: renforcement des racines, tire-bouchons, vegetations, essais in situ, stabilite de pente., 1. Introduction It is well known that roots can positively increase soil strength through reinforcing soil as inclusions inducing a mechanical effect. Part of the soil shear load is taken [...]

Osseointegrated dental implants in the vicinity of oral squamous cell carcinoma (OSCC) will become more common given the increasing popularity of dental implants. Reports and studies of OSCC around dental implants are rare, as is the topic of how to handle OSCC surgically when implants are in contact with the tumour. In view of this uncertainty, a histological study was performed to assess tumour behaviour around implants. The aim was to determine whether an implant facilitates inward growth of the tumour and how this should be taken into account during staging and treatment planning. A total of 20 specimens were collected. The implants were macroscopically in contact with OSCC in 13 of the 20 specimens. Histologically, tumour tissue near the implant was indeed confirmed in nine of these cases. In seven cases, tumour invasion had led to resorption of the underlying jaw bone; tumour between the bone–implant interface was identified in only two of these cases, but without downward growth along the implant. In conclusion, no proof was found to confirm that the bone–implant interface is a preferred route for invasion. Therefore, dental implants in the vicinity of OSCC should not influence staging and treatment planning in this regard. [ABSTRACT FROM AUTHOR]

The current standard of care in alveolar cleft repair is timing the procedure in the mixed dentition stage and making use of autologous bone to restore the maxillary defect. Using a synthetic bone substitute bypasses the risk of donor site morbidity and reduces the operation time. In this study, the outcome of alveolar cleft repair using microporous beta-tricalcium phosphate (β-TCP) was investigated in patients with unilateral cleft lip and palate. Twenty patients were enrolled prospectively in this study, divided between two centres. Continuity of the alveolar process, recurrence of oronasal fistulas, and eruption of teeth into the repaired cleft were evaluated at 1 year postoperative. Also, cone beam computed tomography scans were analyzed using a volume-based semi-automatic segmentation protocol. No adverse events were reported. The mean residual bone volume in the repaired cleft at 1 year postoperative was 65%. There was no recurrence of oronasal fistula. Furthermore, 90% of the teeth adjacent to the cleft erupted spontaneously and all patients showed a continuous alveolar process. Secondary alveolar grafting using microporous β-TCP can safely be used in the clinical situation. Residual calcified tissue, canine eruption, and complication rates at the recipient site are comparable to those with autologous grafts. [ABSTRACT FROM AUTHOR]