Siloranes–Suitability of a Novel Adhesive for Orthodontic Bracket Bonding

Recently, an epoxy-based resin-Filtek Silorane-has been proposed for restorative fillings. It was the aim of the investigation to evaluate the suitability of this novel resin for orthodontic bracket bonding on unground enamel. Shear bond strength was measured for two adhesives-Filtek Silorane, Transbond XT-in combination with steel, ceramic and polymer brackets. For Filtek Silorane etching was performed with the Silorane self-etching primer, as well as phosphoric acid. The Transbond XT samples were etched with phosphoric acid only and served as the control group. All samples were thermo-cycled (1000×, 5–55 °C). Shear testing was carried out with an Instron 3344. In addition, ARI scores were evaluated. The Shear bond strength showed a weak adhesion of Filtek Silorane to unprepared enamel, either with the self-etching primer or the conventional etching (0.87–4.28 MPa). The Shear bond strength of the control group was significantly higher (7.6–16.5 MPa). The ARI scores showed a clear failure at the enamel-adhesive interface for all Filtek Silorane samples. For the combination of Transbond XT and different brackets the failure was found at the adhesive–bracket interface. The novel epoxy-based resin Filtek Silorane is not appropriate for bracket bonding to unprepared enamel.

Investigating a Commercial Functional Adhesive with 12-MDPB and Reactive Filler to Strengthen the Adhesive Interface in Eroded Dentin

To compare the adhesive interface of eroded dentin formed by a functional dental adhesive and a gold standard strategy, by testing microtensile bond strength (μTBS), hardness/elastic modulus. Permanent sound human molars were randomly allocated to four experimental groups, all subject to artificial erosion (0.05 M citric acid; 3× daily, 5 days). Groups included control Clearfil SE Bond 2 (CFSE), and experimental group Clearfil SE Protect (CFP), at two different time points-immediate (24 h) and long term (3 months–3 M). Samples were sectioned into microspecimens for μTBS (n = 8) and into 2-mm thick slabs for nanoindentation assays (n = 3). Groups CFSE_3M and CFP_3M were stored in artificial saliva. Statistical analysis included two-way ANOVA for μTBS data, while hardness/modulus results were analyzed using Kruskal–Wallis H Test (significance level of 5%; SPSS v.27.0). Although no significant differences were found between mean μTBS values, for different adhesives and time points (p > 0.05), a positive trend, with μTBS rising in the CFP_3M group, was observed. Regarding hardness, no significant differences were seen in the hybrid layer, considering the two variables (p > 0.05), while the reduced elastic modulus rose in CFP_3M when compared to 24 h. Thus, CFP shows similar mechanical and adhesive performance to CFSE in eroded dentin, although it may comprise promising long-term results. This is advantageous in eroded substrates due to their increased enzymatic activity and need for remineralization.

Application Modes Affect Two Universal Adhesive Systems’ Nanoleakage Expression and Shear Bond Strength

Objectives. The aim of this study was to evaluate the shear bond strength and the nanoleakage expression of CLEARFIL Universal Bond Quick and Tetric N-Bond adhesive systems bonded to dentin. Materials and Methods. 100 freshly extracted human premolar teeth were utilized. The teeth were sectioned to expose dentin. All dentin specimens were assigned into 4 experimental groups; 2 groups had Universal Bond Quick (Universalself group) and Tetric N-Bond (Tetricself group) applied in the self-etch mode, while 2 groups had Universal Bond Quick (Universaltotal group) and Tetric N-Bond (Tetrictotal group) applied in the total-etch mode. n = 15 for shear bond strength and n = 10 for nanoleakage experiment. One-way ANOVA and Kruskal-Wallis test were utilized to analyze the shear bond strength test and the nanoleakage expression, respectively. Results. The highest significant bond strength value was recorded by the Tetricself specimens ( p < 0.05 ) when compared to the remaining three groups. There were no statistically significant differences between the shear bond strength values recorded in the Tetrictotal, Universalself, and Universaltotal groups ( p < 0.05 ). Both bonding systems applied in the self-etch mode (Universalself, Tetricself) had no silver nitrate deposits in the hybrid layer and the hybrid layer-adhesive interface ( p < 0.001 ); however, both bonding systems applied in the total-etch mode (Universaltotal, Tetrictotal) had silver nitrate deposits in the hybrid layer, the hybrid layer-adhesive interface, and the bonding layer ( p < 0.001 ). Conclusion. Applying the Universal Bond Quick and Tetric N-Bond in the self-etch mode exhibited better results in terms of nanoleakage expression. Universal Bond Quick showed the stability of the shear bond strength to dentin when applied using the total-etch or self-etch modes. Tetric N-Bond showed significant deterioration in bond strength when applied in the total-etch mode and exhibited the highest bond strength when applied in the self-etch mode.

One-Year Clinical Aging of Low Stress Bulk-Fill Flowable Composite in Class II Restorations: A Case Report and Literature Review

Bulk-fill flowable composites provide functional and aesthetic restorations while eliminating incremental composite layering and saving time. The degradation of the adhesive interface with subsequent gap formation is a concern when adhesively luted restorations are placed. Moreover, the number of adhesive interface failures increases when they are exposed to long-term water storage. The aim of the present study was to evaluate the morphological characteristics of the tooth-composite interface in class II cavities restored with a low stress bulk-fill flowable composite after aging in an oral environment. We describe a case of a patient with class II cavities in four premolars restored with a low stress bulk-fill flowable composite Surefil SDR (Dentsply DeTrey GmbH, Konstanz, Germany). The occlusal part was restored with nano-hybrid resin composite Ceram X Mono (Dentsply DeTrey GmbH). After one year of clinical function, the teeth were extracted and examined in a scanning electron microscope (SEM). It can be concluded that the application of bulk-fill covered with conventional composite seems to provide the homogeneous and stable bond to tooth structure after one year of aging in an oral environment. However, some defects within the dentin-resin composite interface were observed.