De nombreux paramètres interviennent dans la longévité des inlays/onlays réalisés par CFAO tels que l’usinabilité et les propriétés mécaniques des matériaux utilisés, l’adaptation de la restauration ainsi que la qualité de l’interface entre le matériau de restauration en céramique ou en composite et le matériau d’assemblage. Dans un premier temps, au travers d’une revue systématique de la littérature, nous avons sélectionné les méthodes expérimentales et les paramètres permettant d’évaluer l’adaptation de ces restaurations. Il existe des techniques en 2D qui mesurent l’espace dent-matériau à des points de référence présélectionnées et des techniques en 3D (Triple-scan, micro-CT) qui mesurent l'ensemble de l'interface. Cette revue de la littérature nous a permis de mettre en évidence que : le matériau de restauration, le type de préparation, le vieillissement, le collage ou non de la restauration et des paramètres propres à la CFAO ont une influence sur l’adaptation. Dans un deuxième temps, nous avons étudié les propriétés mécaniques de blocs en céramique et en composite et l’adaptation interne in vitro d’inlays usinés à partir de ces mêmes matériaux. L’influence de la nature du matériau de restauration et de son usinabilité sur l’adaptation a été mise en évidence. La troisième partie de notre travail a porté sur la qualité de cette interface par un test de résistance en microtraction et une analyse du type de fracture. Une relation étroite a été démontrée entre la microstructure du bloc testé et le type de traitement de surface utilisé. Ce travail a souligné l’importance d’utiliser plusieurs méthodologies et de les croiser entre elles afin de mieux corréler nos résultats. L’étude du vieillissement de ce joint dento-prothétique constitue un travail à part entière dans laquelle certaines méthodologies utilisées dans cette thèse (profils de rupture, essais mécaniques) peuvent être transposées / Several parameters are involved in the longevity of CAD-CAM inlays/onlays restorations such as the machinability and mechanical properties of the materials used, the adaptation of the restoration and the quality of the resin cement-ceramic or composite interface. Initially, through a systematic review of the literature, the experimental methodologies and parameters to evaluate the adaptation of these restorations were selected. The gap between the tooth and the material, at preselected reference points, is measured by 2D techniques. 3D techniques (Triple-scan, micro-CT) are able to measure the entire interface. This review of the literature allowed us to highlight that: the restorative material, the preparation design, aging, the use of a bonding-system and parameters regarding the CAD-CAM technology have an influence on the marginal adaptation. Afterwards, we assessed the mechanical properties of CAD-CAM ceramic and composite blocks and the internal adaptation in vitro of inlays milled with these same materials. The influence of the nature of the restorative material and its machinability on adaptation was put forward. The third part of our work focused on the quality of this interface using a microtensile bond strength test and a fracture type analysis. A tight association has been shown between the microstructure of the tested blocks and the type of surface treatment applied. This work underlined the importance of using several methodologies and crossing them to better correlate our results. Studying the aging of this dento-prosthetic joint constitutes a whole work in which some approaches used in this thesis (fracture profiles, mechanical tests) can be implemented and transposed

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this study was 1) To determine the impact of eliminating or delaying the photo-activation procedure on the polymerization contraction stress (PCS)and degree of conversion (DC) of a dual-cured resin luting agent, and 2) To determine the amount of delay in photo-initiation of the dual-cured resin cements that can achieve a reduced PCS value with the highest possible DC. The amount of PCS and DC of a dual-cured resin luting agent was determined using a tensometer and ATR spectroscopic technique, respectively. Photo-activation delay in seven tested groups was 0 min, 2 min, 4 min, 6 min, 8 min, 10 min and no photoactivation. Five samples for each group were tested. There were two hypotheses for this study: 1) A significant decrease in the amount of PCS associated with delayed photo-activation, and 2) A significant increase in DC associated with delayed photo-activation.The PCS of the chemical-cure luting agent had significantly lower value than all of the light-cure groups. For the light-cure groups, those with a 4-min delay had higher PCS than those with delays of 0 min, 2 min, 6 min, 8 min, and 10 min. The zero (0)-min and 2-min delay had higher PCS than the 6-min, 8-min, and 10-min delay; and the 6-min delay had higher PCS than the 8-min and 10-min delay. The PCS decreased 0.086 MPa per minute of delay. The DC of the chemical-cure luting agent had significantly lower value than the 2-min, 4-min, 6-min, 8-min, and 10-min delaylight cure. For the light-cure groups, 0-min delay had a lower DC than the 2-min, 4-min, 6-min, 8-min, and 10-min delay; 2-min delay had lower DC than 4-min, 6-min, 8-min, and 10-min delay. The 4-min and 6-min delay had lower DC than the 8-min and 10-min delay; and the 8-min delay had a lower degree of conversion by peak area than the 10- minute delay. The DC increased 0.021 per minute of delay. Extending the stress relief period of the dual-cured luting agents by delaying light activation has a significant impact on PCS and DC values. There was significant decrease in PCS with the delayed light curing of the resin luting agent. Significant increase in DC was noticed when light activation was delayed in the dual-cured resin luting agents.

Indiana University-Purdue University Indianapolis (IUPUI) / Potential problems of one-step adhesives have been identified, including water uptake and subsequent plasticization, water-and enzyme-induced nanoleakage, and the presence of voids due to phase-separation or osmosis. Clinically, adhesive failures due to marginal degradation present as retention loss, marginal discoloration, and secondary caries. However, the mechanisms of adhesive interface degradation of self-etching and self-bonding resin luting agents are not fully understood. The objective of the study was to investigate adhesive layer degradation by using a nanoleakage technique with five different resin luting agents. Materials and Methods: Five different resin luting systems, Variolink II, Panavia F2.0, RelyX Unicem, RelyX Unicem2, and Maxcem Elite were evaluated in this study. The 25 dentin specimens were randomly divided into five resin luting agent groups. Flat dentin surfaces were created mid-coronally and were luted with luting agents. Then, each tooth was sectioned occluso-gingivally. The first half of each tooth was used as a control group and the other half was used as the experimental group. The control group was immersed in artificial saliva at 37°C and SEM examination with chemical analysis was performed within 48 hours. In the tested group, all specimens were immersed in artificial saliva at 37°C for 10 days and thermocycled. For the SEM examination, the specimens were immersed in a 50-percent ammoniacal silver nitrate solution for 24 hours.22 SEM was used for observation of silver penetration of the specimens. Three scan lines were selected. For elemental analysis, natural apatite, olivine minerals, and pure silver metal were chosen as standards for Ca, Si and Ag. Data were analyzed using ANOVA with a 5-percent significance level. Results: At the bottom of the hybrid layer, there was no significant difference in silver uptake within the adhesive interface between luting agents (p > 0.05) and there was no significant change in silver uptake within the adhesive interface after thermocycling (aging) (p > 0.05). Conclusion: All resin luting agents exhibited nanoleakage after both 24-hour storage and 10-day storage with thermocycling.

Le fil directeur durant cette période de recherche a été l’étude d’une interface dentine/titane assemblée par collage. L’objectif était d’optimiser et de simplifier des étapes du protocole d’assemblage, d’améliorer et d’étudier les performances de l’interface adhérente. Dans ce travail, les interfaces ont été testées in vitro par cisaillement.Cette étude a comporté trois volets :Le but de la première étude a été d’évaluer un assemblage par ciment verre ionomère (CVI), le Fuji Plus®, appliqué en association avec des adhésifs auto-mordançants sur la dentine. Trois des combinaisons « système auto-mordançant/Fuji Plus® » ont été appliquées et les résultats obtenus montrent des améliorations significatives entre 9% et 44% par rapport aux valeurs obtenues sur des éprouvettes de témoin.Le second volet expérimental a eu pour objectif de tester la compatibilité entre cinq systèmes adhésifs auto-mordançants (SAM) et deux composites d’assemblage (CA). Les SAM1 se sont révélés totalement incompatibles avec les CA chémopolymérisés ou duals. Inversement, les SAM2 étaient compatibles avec des CA chémopolymérisants ou duals. Une corrélation positive a été trouvée entre le pH des SAM ou les résines testées et les données de cisaillement.La dernière étude a été dédiée à l’évaluation de l'effet du stockage dans l’eau sur la résistance à la flexion (σf) et sur la résistance au cisaillement (RC) d’une interface dentine/titane assemblée par quatre résines adhésives auto-mordançantes (MRAM). Cette étude a montré que le stockage dans l'eau durant 60 jours a affecté négativement la résistance à la flexion de certains matériaux. L'adhésion dentine/titane offerte par Rely X® et G-Cem® était significativement plus élevée que celle de Maxcem® et SmartCem2®. / The aim of this work was to study a bonding dentin/titanium interface. The objective was to optimize and simplify the steps of the bonding protocol, improve and know well the performance of the adhesive interface. In this work, all interfaces have been tested in vitro by shearing.This study included three parts :The purpose of the first study was to evaluate an assemblage by glass ionomer cement (GIC), the Fuji plus®, applied in combination with self-etch bonding system on dentin. Three combinations "system self-etching / Fuji Plus®" were applied and the results obtained by test showed significant improvements from 9% to 44% higher than the values obtained on control specimens.The second experimental part was designed to test the compatibility between five self-etch bonding systems (SEBS) and two resin luting cements (RLC). Significant differences of bond strength in shear were observed according to both the curing mode of the RLC and the adhesive. The SEBS1 proved totally incompatible with chemical or dual cured RLC. Conversely, two-steps SEBS were compatible with RLC chemical/dual cured RLC. A positive correlation was found between the pH of the SEBS or the tested resins and the shear data.The latest study was devoted to evaluate the effect of the storage condition on flexural strength (σf) and shear bond strength (SBS) of a dentin/titanium interface assembled by four self-etch adhesive resin (SEARC). This study showed that the storage in water for 60 days has negatively affected the bending resistance of certain materials. The dentin/titanium adherence offered by Rely X® and G-Cem® was significantly higher than that of Maxcem® and SmartCem2®.

No description available.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This study evaluated the effect of different types of luting cement and post configuration on the bonding to intra-radicular dentin in different depths. One hundred and twenty roots received endodontic treatment and were post space preparation for fixation of glass fiber post in the configurations: serrated/parallel Reforpost X-Ray (S); and smooth/conical Exato Cônico (L). The posts were fixed with cements: RelyX ARC (ARC), RelyX Luting 2 (LU), RelyX Unicem (UN), Maxicem (MAX) and Cement-Post (CP). The roots were sectioned transversally, getting two disks of 1mm of thickness for third of the root portion: cervical (C), medium (M) and apical (A), and submitted to the micropush-out test with speed of 0.5mm/min. The bond strength values (MPa) were submitted to the analysis of variance in scheme of subdivided parcel and Tukey test (p0.05). There was significant difference among the cements types (p<0.0001), among the localizations (p<0.0001) and the interaction cement x localization was significant (p<0.0001). The post configuration did not influence the bond strength values. The cements LU and UN presented the highest values of bonding in all extension of root dentin. The cements ARC and CP presented similar bonding values in cervical third, however, the bond strength decreased in the crown-apex direction for the ARC. The cement MAX presented the lowest values of bonding. / Este estudo avaliou o efeito do tipo de cimento de fixação e da configuração de retentores intra-radiculares na adesão à dentina intra-radicular em diferentes profundidades. Cento e vinte raízes receberam tratamento endodôntico e foram aliviadas para fixação de retentores intra-radiculares de fibra de vidro nas configurações: serrilhado/paralelo Reforpost X-Ray (S); e liso/cônico Exato Cônico (L). Os pinos foram fixados com cimentos: RelyX ARC (ARC), RelyX Luting 2 (LU), RelyX Unicem (UN), Maxicem (MAX) e Cement-Post (CP). As raízes foram seccionadas transversalmente, obtendo-se 2 discos de 1mm de espessura por terço da porção radicular aliviada: cervical (C), médio (M) e apical (A), e submetidos ao teste de micropush-out com velocidade de 0,5mm/min. Os valores de resistência adesiva (MPa) foram submetidos à análise de variância em esquema de parcela subdividida e teste de Tukey (p<0,05). Houve diferença significativa entre os tipos de cimentos (p<0,0001), entre as localizações (p<0,0001) e a interação cimento x localização foi significativa (p<0,0001). A configuração do pino não influenciou nos valores de resistência adesiva. Os cimentos LU e UN apresentaram os maiores valores de adesão em toda extensão da dentina radicular. Os cimentos ARC e CP apresentaram valores de adesão no terço cervical semelhantes, contudo, a resistência adesiva decresceu no sentido coroa-ápice para o ARC. O cimento MAX apresentou os menores valores de adesão. / Mestre em Odontologia