Utilisation d'un nouveau matériau de coiffage pulpaire (la Biodentine )

NICE-Antenne de St Jean d'Angely (060882105) / SudocNICE-BU Médecine Odontologie (060882102) / SudocSudocFranceF

L 'hypersensibilité dentinaire (étiologies, mécanismes et traitements)

NICE-Antenne de St Jean d'Angely (060882105) / SudocNICE-BU Médecine Odontologie (060882102) / SudocSudocFranceF

Les adhésifs automordançants sont-ils plus adaptés à la surface dentinaire préparée avec le laser Er : Yag ? (étude in vitro et sous pression trans-dentinaire)

Notre étude se propose d évaluer les interactions entre trois types d adhésifs automordançants (le CSE Bond, le XenoIII et le iBOND) et le substrat dentinaire préparé au laser Er : YAG ou à la fraise. Les surfaces préparées avec le laser ont été analysées en microscopie optique, électronique à balayage et en XPS. Nous avons ensuite étudié les interactions entre ces trois adhésifs automordançants et le substrat. Nos études de mouillabilité ont montré que la surface préparée au laser est plus hydrophile et poreuse que la surface fraisée. Les monomères acides des adhésifs automordançants sont eux aussi hydrophiles et pénètrent plus rapidement sur la surface préparée au laser. Un essai mécanique de cisaillement avec pression trans-dentinaire a ensuite été conçu de manière à évaluer l adhérence du joint dentinaire collé. L adhérence sur surface fraisée s est avérée statistiquement équivalente à celle de la surface préparée au laser pour le Xeno III et supérieure pour les deux autres. Le CSE bond présente les meilleurs résultats sur les deux types de surfaces. Les essais de cisaillement réalisés sur le CSE Bond avec pression ont montré des valeurs d adhérence comparativement plus faibles sur surfaces fraisées alors qu elles restaient équivalentes sur surfaces préparées au laser. La présence de boue dentinaire sur surface fraisée tend à favoriser l adhérence d adhésifs chargés. Cependant, le collage sur une surface propre et préparée au laser, avec ou sans pression trans-dentinaire, est plus reproductible que celui obtenu sur une surface fraisée recouverte de boue dentinaire.The goal of this study is to estimate the interactions between three self etching adhesive systems (CSE Bond, Xeno III and iBond) and dentin prepared using either burr or Re : YAG laser. Optica microscopy, SEM and XPS have been used to characterize lased surfaces. We have then studied the interactions between these three self etching adhesive systems and the substrate. Wettability studies have shown that lased surfaces were more absorbents and porous than burred surfaces. The self etching acid monomers are also absorbents and penetrate faster in lased surfaces. We have then set up a mechanical shearing test in order to evaluate the shearing strength of the bond. Shearing strength seems to be higher on burred surfaces than on lased surfaces. However these in vitro results are obtained on a dry surface which is not really physiological. We have thus adapted the device in order to generate a trans-dentinal pressure using demineralised water. With pressure, CSE Bond shearing strengths appeared to be comparatively lower on burred surfaces but remained equivalent on lased surfaces. We have also carried out a study of resin tags for the three self etching adhesive systems and for the two preparation techniques. The smear layer presence on burred surfaces seems to improve the bonding strength of filled adhesive resin. However these bonding strength measurements on a clean and lased surface with or without trans-dentinal pressure are more reproductive than for a burred surface with smear layer.NICE-BU Sciences (060882101) / SudocSudocFranceF

Determination of the filler-matrix interface strength of dental composites from bending tests

International audienc

Finishing and polishing effects of multiblade burs on the surface texture of 5 resin composites: microhardness and roughness testing

International audienc

A numerical, theoretical and experimental study of the effect of thermocycling on the matrix-filler interface of dental restorative materials

International audienc

Theoretical prediction of dental composites yield stress and flexural modulus based on filler volume ratio

International audienc

Microhardness evaluations of CAD/CAM ceramics irradiated with CO₂ or Nd:YAP laser

International audienceBackground and aims. The aim of this study was to measure the microhardness values of irradiated computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics surfaces before and after thermal treatment. Material and Methods. Sixty CAD/CAM ceramic discs were prepared and grouped by material, i.e. lithium disilicate ceramic (Emax CAD) and zirconia ceramic (Emax ZirCAD). Laser irradiation at the material surface was performed with a carbon dioxide laser at 5 Watt (W) or 10 W power in continuous mode (CW mode), or with a neodymium:yttrium aluminum perovskite (Nd:YAP) laser at 10 W on graphite and non-graphite surfaces. Vickers hardness was tested at 0.3 kgF for lithium disilicate and 1 kgF for zirconia. Results. Emax CAD irradiated with CO2 at 5 W increased microhardness by 6.32 GPa whereas Emax ZirCAD irradiated with Nd:YAP decreased microhardness by 17.46 GPa. Conclusion. CO2 laser effectively increases the microhardness of lithium disilicate ceramics (Emax CAD)

CO₂ laser dentin surface treatment most effectively increased ceramic shear bond strength

International audienceBackground and aims: The purpose of this study is to determine the effect of CO2 laser irradiation in comparison with sandblasting (Sb), hydrofluoric acid (Hf) and silane coupling agent (Si) on shear bond strength (SBS) of resin cement to CAD/CAM ceramics bonded to dentin. Material and Methods: Forty-eight (CAD/CAM) ceramic discs were prepared and grouped by material, i.e. lithium disilicate (Emax CAD) and zirconia ceramic (Emax ZirCAD), distributed into four different groups: group A, lithium disilicate (Li) CO2/HF/Si; group B, Li: HF/Si; group C, zirconia (Zr) CO2/Sb/Si; group D, Zr: Sb/Si. Results: It was shown significant difference between irradiated and non-irradiated groups in terms of shear bond strength for zirconia ceramics (p value = 0.039). Conclusion: CO2 laser irradiation increases shear bond strength for both CAD/CAM ceramics bonded to dentin