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The purpose of this study was to assess the bond strengths of three self-adhesive resin cements (Rely X Unicem, Maxcem and Multilink Sprint) fixing dentine to four different restorative substrates (Ni-Cr alloy, E-Max glass-ceramic, Y-TZP Zirconia and Adoro micro-filled composite) and to compare their performances with those of two conventional dual-cured luting cements (Variolink II + Total-etch Excite DSC and Multilink Automix + Self-etching Primer A + B). Cylindric specimens (5 x 5 mm) were prepared with the four restorative materials for bonding to human dentine. Three surface treatments were performed depending on the restorative material: (i) Al2O3 50 microm sandblasting (Ni-Cr, Adoro), (ii) #800 SiC polishing (Zirconia, E-Max), (iii) hydrofluoric acid (HF)-etching (E-Max). Twenty-five groups (n = 10) were designed according to luting cements, restorative materials and surface pre-treatments. In some experimental groups, Variolink II and Multilink Automix were coupled with, respectively, a silane primer (Monobond S) and an alloy/zirconia primer (Multilink A/Z primer). Specimens were stored in distilled water at 37 degrees C for 24 h and then loaded in shear until failure. Variolink II and Multilink Automix showed the highest bond strengths, regardless of the restorative substrate, when used with dentine bonding systems and primers, while the weakest bonds were with Maxcem. The bond strength recorded with the two other self-adhesive cements depended on the nature of the restorative substrate. Increasing retention at the interfaces (i.e., HF ceramic etching) and using specific primers significantly improves the bond strength of luted restorative materials to dentine.

Objectives: The aim of this study was to evaluate the effect of drying time and primer pre-application (35% HEMA in water) on water spreading/infiltration on dentin. Methods: Freshly extracted molars were embedded in resin and sectioned on their coronal side. Flat occlusal dentin surfaces were prepared using wet SiC paper from nos. 80–4000. A computerized contact angle device complementing a special software (Wingoutt R ) was used to measure the contact angle (θ) kinetics of a reference liquid (pure H 2 O) in the ten groups each of ten dentin surfaces during 120 s: Gp1: etched (37% phosphoric acid for 15 s) and blot-dried; Gp2: 3 s dried; Gp3: 5 s air-dried; Gp4: 10 s air-dried; Gp5: 20 s air-dried; Gp6: 30 s air-dried; Gp7: 1 min dried with hair dryer; Gp8: 5 s air-dried and HEMA treated; Gp9: 30 s air-dried followed by HEMA treatment; Gp10: HEMA treated prior to 30 s air-drying. three drops were applied on each sample. 40 contact angles were recorded for each drop with a frequency of one measure every 3 s. A one-way ANOVA test was used for data analysis. A PLSD test was conducted to identify statistical differences between pairs of groups at a reliability level of 95%. Results: At each measurement time, air-drying, whatever its duration, significantly decreased the wetting ability of the pure water on the etched dentin in comparison with the blot-dried group. The contact angle increases with drying time. No significant differences in water contact angle were obtained between 3, 5 and 10 s in spite of a slight decrease in the spreading/infiltration ability of water the longer the drying time. HEMA increases the spreading/infiltration ability of water on 5 or 30 s air-dried etched dentin surfaces; 30 s air-drying did not alter the spreading/infiltration ability of the water on etched and HEMA treated dentin. Significance: Dentin hydrophobicity increases depending on air-drying time. HEMA-based primer allows to prevent collagen collapse, which may be created by air-drying and partly rewet the collapsed collagen network.

International audience; Dentine is the fundamental substrate of restorative dentistry, and its properties and characteristics are the key determinants of restorative processes. In contemporary restorative techniques, bonding to Dentine is created by the impregnation of the demineralised dentine by blends of resin monomers. In this paper, a numerical model of dentinal infiltration is proposed. The aim is to follow the resin front and to point out the optimal parameter set. The main tool is a level set technique to follow the evolving interface. It is coupled with the Navier-Stokes equation where capillary effect gives rise to the appearance of a new term in the variational approach than discretised by finite elements. Using an appropriate geometry representing demineralised dentine, the moving front is observed. First, a simulation of porosimetry test is achieved in order to validate the model. The two expected pore sizes are detected and the simulation also points out limitations of mercury intrusion porosimetry test in an educational way. Then a wetting fluid (representing the dental resin) is numerically infiltrated. In the dentinal porous network, capillarity is taken into account in our model by including a capillary term. A crucial conclusion is drawn from this study: resin application time by practitioners is sufficient if, in the infiltration process, the wetting phase is the resin.

The aim of this study was to evaluate the compatibility between five self-etching bonding systems (SEBSs) and two resin luting cements (RLCs) assessed by use of an in vitro dentin shear bond test.The selected RLCs were: Variolink II in a dual-cure mode and Multilink in a self-cure mode. The SEBSs combined with the RLCs were: two one-step SEBSs (One Up Bond F and Xeno III) and three two-step SEBSs (Clearfil SE Bond, Unifil Bond, and Xeno III primer coupled with Clearfil SE Bond bonding resin as an experimental combination). One hundred fifty human molars were divided into ten groups of fifteen samples each. The samples were tested in shear after seven days of storage at 100% RH and 37°C. After each test, the failure mode was recorded.Significant differences in shear bond strength (SBS) were observed according to both the curing mode of the RLC and the adhesive. The one-step systems Xeno III and One Up Bond F revealed a total incompatibility when bonded with the chemical-curing RLC. Conversely, the two-step SEBSs were compatible with chemical and dual-curing RLC. Failure modes and shear values were in good agreement. A positive correlation was found between the pH of the tested adhesive solutions or resins and the SBS data

Objectives The objectives of this study were to assess demineralized dentin porosity and quantify the different porous features distribution within the material using mercury intrusion porosimetry (MIP) technique. We compared hexamethyldisilazane (HMDS) drying and lyophilization (LYO) (freeze-drying) in sample preparation. Methods Fifty-six dentin discs were assigned into three groups. The control (CTR) group discs were superficially acid-etched (15 s 37% H 3 PO 4 ) to remove the smear layer and then freeze-dried whereas LYO and HMDS groups samples were first totally demineralized using EDTA 0.5 M and then freeze-dried and HMDS-dried respectively. MIP was used to determine open porosity and pore size distribution of each pair of samples. Field emission scanning electron microscopy (FESEM) was used to illustrate the results. Results The results showed two types of pores corresponding either to tubules and micro-branches or to inter-fibrillar spaces created by demineralization. Global porosity varied from 59% (HMDS-dried samples) to 70% (freeze-dried samples). Lyophilization drying technique seems to lead to less shrinkage than HMDS drying. FESEM revealed that collagen fibers of demineralized lyophilized samples are less melted together than in the HMDS-dried samples. Significance Demineralized dentin porosity is a key parameter in dentin bonding that will influence the hybrid layer quality. Its characterization could be helpful to improve the monomers infiltration.

The aims of this study were to evaluate the in vitro shear bond strength of the dentin-titanium interface mediated by Fuji Plus, a resin-modified glass-ionomer cement, applied in combination with several self-etching bonding systems, and to compare the values obtained with those of SuperBond, chosen as a reference luting agent.The self-etching bonding systems used in combination with Fuji Plus were AdheSE, Xeno III, Clearfil SEBond, Unifil Bond, and an experimental self-etching bonding system comprising the sequential application of Xeno III and the bonding component of SE Bond. Two control groups were also tested: a negative control with Fuji Plus along with its conditioner (10% ferric chloride, 2% citric acid solution); and a positive control with the resin cement SuperBond. One hundred five human molars were used to prepare seven groups of fifteen samples each. The samples were tested in shear after 7-day storage at 100% relative humidity and 37 degrees C.Three of the tested combinations of self-etching bonding systems with Fuji Plus significantly improved in comparison with the negative control group, from 9% to 44%. The self-etching bonding systems obtained using Fuji Plus in combination with Clearfil SEBond, Unifil Bond, and the experimental system were not different from those obtained with SuperBond.

To compare the penetration and the imperviousness of two pit and fissure sealants according to surface treatments involving different cleaning procedures with or without subsequent acid etching.Two sealants were used: a resin-based sealant (Concise White Sealant) and a compomer-based material (Dyract Seal) coupled with an enamel-dentin bonding agent (Dyract Seal and PrimeBond NT). Extracted molars (n = 120) were randomly divided into 12 groups: 4 control and 8 experimental groups that received different surface treatments. Pumice, alumina, or bicarbonate was used to clean the surfaces. Phosphoric acid or non-rinse conditioner was used as acid etching agents. After sealing, the Concise White Sealant groups were directly thermocycled for 1800 cycles, while the Dyract Seal groups were stored in water for one month before thermocycling. After apex sealing and varnish coating, the fillings were stained with silver nitrate and embedded. Three to 6 cross sections of 200 microm each were made per sample to assess both sealant penetration (% of the length of the fissure) and the imperviousness of the seal (scores method).Concise White Sealant achieves a better enamel sealing than Dyract Seal when the teeth are treated with air abrasion or air polishing followed by etching. Acid etching is essential for good sealing, whatever the material and cleaning technique tested. Only the combination of air abrasion and phosphoric acid etching yielded a leak-free joint.This study clearly shows that penetration and sealing are two different phenomena. Ideally, an efficient sealant must have a good sealing ability and a high rate of infiltration as well, but these two properties probably do not have the same clinical relevance. The imperviousness of the seal remains the most important requirement.

The loss and replacement of anterior maxillary teeth pose several challenges. Treatment must successfully address immediate tooth replacement, esthetics, patient comfort, and psychologic acceptance. The purpose of this case report is to present a prosthetic and surgical technique for immediate tooth replacement following extraction in an area of severe localized bone loss. Combined full- and partial-thickness flaps associated with the use of Bio-Oss collagen grafting material and a Bio-Gide membrane were used for alveolar ridge reconstruction. To improve the final esthetic result, a connective tissue graft was used to increase ridge volume and papillary height.

International audience; Purpose: To test how the number of sections affects the maximum depth of tracer penetration.Materials and methods: This study was simultaneously performed in three different centers. C-shaped Class V cavities were made on 60 human third molars. The cavities were located across the cementum-enamel junction. One restorative system was used: Scotchbond Multi-Purpose and Z100. After restoration, the samples were thermally cycled 3000 times, between 5 and 55 degrees C with a dwell time immersion of 10 seconds. Silver nitrate was used by two centers and basic fuchsin was used by the third. The teeth were longitudinally sectioned with a diamond saw: 5 sections per tooth provided 10 surfaces for evaluation. The penetration of the tracer was recorded on a scale from 0 to 3. The deepest leakage per restoration was identified for comparison with lesser measured values elsewhere in the tooth. The Spearman test was applied to evaluate the relationship between the reference and data from one, two and three sections (i.e. two, four and six measurements). The Kruskal-Wallis test was applied to compare the three centers.Results: Whatever the study center, the Spearman correlation coefficient (r(s)) increased as a function of the number of sections (S) up to three: Center 1 (1S, 0.47; 2S, 0.68; 3S, 1.0), Center 2 (1S, 0.60; 2S, 0.99; 3S, 0.99), Center 3 (S1, 0.40; 2S, 0.73; 3S, 1.0). No statistically significant difference was found between the three study centers

Regional odontodysplasia is a localized disorder of tissues of dental origin that results in a ghost-like appearance of the affected teeth. We present a case with a study of gingival tissue around the follicle. The results show evidence of the role of the matrix metalloproteinases and their natural inhibitors by resident cells in this pathosis. An imbalance in the amounts of matrix metalloproteinases and their natural inhibitors is associated with the pathologic breakdown of the collagen.

The objectives of this study were (1) to investigate the effect of operator variability on the shear bond strength of adhesives to dentin and (2) to determine the effectiveness of education on bonding performance for different types of adhesives. Thirty general practitioners were recruited for a CE course by a regional mailing. They used bovine dentin as a substrate for bonding the adhesive system they routinely used in practice and two other materials (no previous experience). Each adhesive OptiBond FL, ScotchBond Multipurpose Plus, ScotchBond 1 and Clearfil SE was applied according to manufacturer's instructions and immediately tested using a shear bond strength test. Shear bond strengths between adhesives and dentin were compared before and after a 90 min lecture on bonding principles and materials. For dentists with and without previous experience with a material, there were no statistically significant differences seen before and after the lecture (paired t-tests, por = 0.05). However, in every case, the bond strengths after the lecture were higher than those before (range of improvement from 15 to 150%). For dentists with routine experience with a particular material, all materials were statistically equivalent after the lecture, although the OptiBond FL was the highest. For dentists who had no previous experience with a material, the ScotchBond 1 had lower bond strengths than the other materials after the lecture. There was a large range in the ability of dentists to manipulate adhesive systems correctly. However, if a dentist has sufficient experience and receives sufficient education, any of these materials can give reasonable results.

New luting agents, described as resin-modified glass-ionomer cements and compomers, have been developed during the last decade to improve the retention of cemented restorations. The aims of this study were to (1) compare the push-out strength of these new luting materials against both conventional cements and bonding luting agents, and (2) evaluate the influence of dentin surface treatment on both glass-ionomer cement and 4-META adhesive resin push-out strength.Conical standardized cavities were drilled in the center of coronal dentin disks. Ninety sandblasted Ni-Cr inlays, divided into nine batches, were luted into the cavities according to the surface treatment and the nature of the following luting agents: zinc phosphate cement, zinc polycarboxylate cement, type 1 glass-ionomer +/- polyacrylic acid, resin-modified glass-ionomer, polyacid-modified composite resin, filled bis-GMA phosphate ester resin, and 4-META adhesive resin +/- application of activated monomer. Each specimen was placed in a holding device, and a steel rod was used to apply a force on the inlay until rupture occurred. The push-out strength was calculated, and the failure mode was controlled.There were significant differences between some of the groups. The highest push-out strength was achieved by the 4-META adhesive resin after application of activated monomer. The lowest value was attained with zinc phosphate and polycarboxylate cements.Both resin-modified glass-ionomer and polyacid-modified composite resin luting materials exhibited a push-out strength similar to resin-based materials. Specific dentin surface treatments significantly enhanced the push-out strengths of glass-ionomer cement and 4-META adhesive resin.

Today, manufacturers provide the orthodontist with a range of adhesive systems which is so wide that is often difficult for the orthodontist to make his choice between them. The adhesive systems fall into four categories: traditional hydrophobic bonding systems, hydrophilic bonding systems, self-etching bonding systems, resin-modified glass ionomer-cements. This article will attempt to examine the first three categories which correspond to those of the composite bonding systems. Following a presentation of bonding assembling and of the required specification of the bonding systems used in orthodontic practice, the three composite bonding systems will be examined along with their advantages/disadvantages before a closing description of the corresponding clinical protocol to be followed. Whenever one of our laboratory experiments enables us to provide experimental evidence, a presentation is made within the related chapters.

The standard techniques used for amalgam restorations often result in a lack of adhesion to mineralized dental tissues. The bonding of amalgam with polymer has been suggested to improve its adaptation to dental tissues. Moreover the polymer involved in the bonding should inhibit the corrosion and the diffusion of metallic ions. The aim of this study was to evaluate in vitro the capacity of bonded amalgam to prevent ionic diffusion and migration. In this respect, an original method employing electrochemical techniques was used to determine the leakage current of bonded amalgam restorations. The electrochemical behaviour of conventional and bonded amalgam restorations was compared using a potentiostat driven by a computerized system (Voltamaster, Radiometer Analytical) with software for specific applications such as chronoamperometry or cyclic voltammetry. Samples of recently extracted teeth of young patients were first examined, and then the results were checked by other experimental assays using protected and unprotected copper sticks. The measurements obtained with chronoamperometry (E = +300 mV/SCE) in Ringer's solution at 37 degrees C showed that after polarization for 30 h the oxidation current decreased threefold for bonded samples (10 microA cm(-2)) as compared with the unprotected samples (35 microA cm(-2)). These results, as well as those obtained with the copper wires, demonstrated that even with two layers of adhesive the bonded joint is permeable to ions probably as a result of the hydrophylic properties of HEMA, a component of the adhesive. However, using five layers of adhesive reduced the ionic current by a factor as large as 10(6).