Progress in Dental Adhesive Materials Cadenaro, M.; Josic, U.; Maravić, T. ...
Journal of Dental Research,
03/2023, Letnik:
102, Številka:
3
Book Review, Journal Article
Recenzirano
There have been significant advances in adhesive dentistry in recent decades, with efforts being made to improve the mechanical and bonding properties of resin-based dental adhesive materials. ...Various attempts have been made to achieve versatility, introducing functional monomers and silanes into the materials’ composition to enable the chemical reaction with tooth structure and restorative materials and a multimode use. The novel adhesive materials also tend to be simpler in terms of clinical use, requiring reduced number of steps, making them less technique sensitive. However, these materials must also be reliable and have a long-lasting bond with different substrates. In order to fulfill these arduous tasks, different chemical constituents and different techniques are continuously being developed and introduced into dental adhesive materials. This critical review aims to discuss the concepts behind novel monomers, bioactive molecules, and alternative techniques recently implemented in adhesive dentistry. Incorporating monomers that are more resistant to hydrolytic degradation and functional monomers that enhance the micromechanical retention and improve chemical interactions between adhesive resin materials and various substrates improved the performance of adhesive materials. The current trend is to blend bioactive molecules into adhesive materials to enhance the mechanical properties and prevent endogenous enzymatic degradation of the dental substrate, thus ensuring the longevity of resin–dentin bonds. Moreover, alternative etching materials and techniques have been developed to address the drawbacks of phosphoric acid dentin etching. Altogether, we are witnessing a dynamic era in adhesive dentistry, with advancements aiming to bring us closer to simple and reliable bonding. However, simplification and novelty should not be achieved at the expense of material properties.
To evaluate the effects of microorganisms’ contamination inside the dispensing syringes of different types of resin-based composites (RBCs).
This study encompassed two sections. First, an anonymous ...electronic survey was submitted via Google forms to Italian dentists to acquire information about composite handling during clinical procedures. Then, a bench test was performed on nanohybrid RBCs differing in matrix chemistry and fillers FiltekTM Supreme XTE (3MTM); Venus Pearl (Kulzer GmbH); Admira Fusion x-tra (Voco) to evaluate the microbial viability on their surfaces with/out photocuring. Uncured RBCs were exposed to standardized inocula of Streptococcus Mutans, Candida Albicans, Lactobacillus Rhamnosus, or mixt plaque in an in vitro model reproducing clinical restorative procedures. Half of the RBC specimens were cured after exposure. Microbial viability was assessed using an MTT-based test. Statistical analysis included three-way ANOVA and Tukey's tests (p<0.05).
Among 300 dentists completing the survey, the majority declared to use the spatula to carry the RBCs from the syringe to the dental cavity (50% same spatula; 35% two spatulas). However, 80% of respondents had personal feelings that using one spatula could be a source of cross-contamination. In vitro results using one spatula showed microbial contamination of all RBCs after one hour of storage. The contamination levels depended on the used strain and RBC type (p<0.0001), but photocuring did not reduce contamination (p = 0.2992).
Microbial species’ viability on uncured RBCs and after photocuring shows the existence of a considerable risk of cross-infection. Clinical procedures in Restorative Dentistry need to acknowledge and to reduce such risk during RBCs handling.
Dentists must be aware of the possibility of cross-infection during restorative procedures, especially when the same spatula is repeatedly used for placing RBC in the cavity.
Carbodiimide (EDC)–based dentin primers preserve hybrid layer (HL) integrity. However, aging >1 y has not been investigated. The present study examined whether the cross-linking effect of EDC was ...reflected in dentin bond strength, endogenous enzymatic activity, and the chemical profile of the HL after 5-y aging in artificial saliva. Noncarious human third molars (N = 42) were cut to expose middle/deep coronal dentin and treated as follows: group 1, dentin etched with 35% H3PO4, pretreated with a 0.3M aqueous EDC primer for 1 min and restored with XP Bond (Dentsply Sirona); group 2, as in group 1 but without EDC pretreatment; group 3, Clearfil SE Bond (Kuraray-Noritake) primer applied to dentin surface, followed by EDC pretreatment as in group 1 and application of bond; group 4, as in group 3 without EDC pretreatment. After composite buildup, the specimens were cut into sticks or slabs, depending on the experiment. All tests were performed at baseline (T0) and after 5 y of aging (T5) in artificial saliva at 37 °C. Microtensile bond strength (µTBS) was tested at a crosshead speed of 1 mm/min until failure. Endogenous enzymatic activity was investigated with in situ zymography. The chemical profile of HL was determined via Raman spectroscopy. Three-way analysis of variance and post hoc Tukey test were used to analyze µTBS and in situ zymography data (α = 0.05). EDC pretreatment and aging significantly influenced µTBS and in situ zymography results (P < 0.05). Higher bond strength and lower gelatinolytic activity were identified in the EDC-treated groups at T5 (P < 0.05), especially in the etch-and-rinse groups. Raman spectra revealed less defined amide III peaks in control specimens at T5. The EDC cross-linking effect persisted in the HL for 5 y in terms of bond strength, collagen structure preservation, and dentinal enzyme silencing.
New zirconia ceramics obtained from blanks having interpenetrating layers with different mechanical and optical properties (yttria gradient concept) have been developed to improve the restoration ...strength without impairing the optical properties; the aim of this study is to evaluate the translucency of crowns made with Katana YML (Yttria Multi-Layered) comparing them to other monolithic restorations.
A.stl file was used to obtain 60 crowns (1.5mm thickness, shade: A2 VITA) with one of the following materials (n=10): 1) Katana Zirconia YML, ultra-rapid sintering (URS, Kuraray-Noritake); 2) 88 ZB PRO (8853S.p.A.); 3) Explore GT-M (Lispning-UpCera); 4) IPS e.max ZirCAD (Ivoclar); 5) Katana Zirconia YML, long sintering cycle (LS); 6) Avencia Block LT, hybrid ceramic (Kuraray). Each crown was checked for external and internal defects under transillumination, weighed to ascertain the accuracy and repeatability and finally polished using Katana Zirconia Twist Dia rubber-wheels. The following methods were used to assess crown translucency: a) Total Transmission, using both white D65 light (TTW) and blue light (TTB) @405 -468 nm peaks (Cybird Gold lamp, DXM): the light (Lx) passing through the crowns was determined as a percentage of the original flow (integrating sphere: Everfine AAIS-2-0.3M; photoradiometer: L100, PCE); b) Contrast ratio, by alternately putting the crowns on a white and black substrate: a colorimeter (Easy-Color, Smart-Vision) was used to calculate the translucency parameter (TP). Data were statistically analyzed (alpha=0.05).
Within TP analysis, YML URS showed the highest translucency among zirconia crowns, inferior only to Avencia hybrid ceramic; however, when analyzed with TTW and TTB, 88ZB and e.max ZirCAD showed slightly higher (~10%) translucency values. When comparing TTW and TTB translucency, a reduction of the residual blue light flow percentage was observed in all groups, although not significant in 88ZB and e.max ZirCAD (P>0.075); the other groups showed a significant drop (p<0.001) of the permeability to blue light. The YML LS displayed the lowest translucency among groups, irrespective of the test used.
The translucency of Katana YML ultra-rapid sintering proved to be higher or similar to the other ceramic and hybrid ceramic materials, depending on the evaluation method. The YML URS permeability to blue curing light was moderately lower (7,83%) in comparison to the value obtained with white light. Katana YML seemed sensible to the sintering technology: when processed with ultra-rapid sintering the restorations were significantly more translucent than the one subjected to long sintering cycle.
Carbodiimides (EDC) have shown a protective role of the hybrid layer in vitro. The longevity of this effect in etch-and-rinse adhesives (E&R) has been shown after 5 years. The present study aimed to ...investigate by means of microtensile bond strength test (µTBS) and in situ zymography whether EDC can preserve bond strength and inhibit endogenous dentinal enzymes even after 10 years of artificial aging.
Sound extracted human molars (n=8 per group per aging time) were cut transversally to expose medium/deep dentin and randomly distributed in the following groups according to the bonding treatment: 1) OB: dentin was etched with H3PO4 for 15s (3M ESPE), blot-dried, and then a 3-step E&R adhesive system was applied (Optibond FL, Kerr); 2) EDCOB: dentin was treated as in OB, with the addition of a pretreatment for 1min with a 0.3M aqueous solution of EDC after the etching step; 3) SB: Dentin was etched for 15s and then a 2-step E&R adhesive system was applied (Scotchbond 1XT, 3M ESPE); 4) EDCSB: treated as SB with the addition of a pretreatment for 1min with a 0.3M aqueous solution of EDC after the etching step. Composite build-ups were made, teeth were cut into 1mm2-thick sticks and subjected to the µTBS after 24h (T0) or 10 years (T10) of aging in the artificial saliva. Additionally, freshly extracted sound molars were prepared (n=5 per group per aging time) with the same adhesive protocols as for µTBS, cut into slices, ground down and subjected to in situ zymography with a fluorescein-quenched gelatin. The data were statistically analyzed (p<0.05).
EDC pretreatment did not impair bond strength at T0 (p>0.05). At T10, although bond strength decreased, this effect was less evident in EDCOB and EDCSB groups (p<0.05).
EDC dentin pretreatment retained the cross-linking effect over 10 years improving the longevity of the dental restoration, possibly by inhibition of the endogenous dentinal enzymatic activity. The higher enzymatic activity at baseline seems to be an indicator of a higher degradation potential of endogenous enzymes after aging.
To evaluate the effects of two SDF dentin surface pre-treatments on bond strength and endogenous enzymatic activity (MMPs) of a simplified universal adhesive at baseline and after 1 year of ...artificial aging.
The middle/deep and enamel/free coronal dentin of 60 sound human molars was exposed. The following groups were formed, according to the dentin surface pre-treatment and etching mode of the universal adhesive (Zipbond, SDI; ZB) used for bonding procedures (n=10): 1) ZB applied in the self-etch mode (SE); 2) Riva Star (R) + SE (RSE); 3) Riva Star Aqua (A) + SE (ASE); 4) ZB applied in the total-etch mode (TE); 5) R + TE (RTE); 6) A + TE (ATE). After 24h, specimens were cut to obtain 1-mm2 thick sticks. The microtensile bond strength (µTBS) test was performed at baseline (T0) and after 1 year (T12) of storage in artificial saliva at 37°C and 100% relative humidity. Fractography analysis of debonded specimens was performed with a scanning electron microscope (SEM). To investigate the effect of SDF on MMPs activity, 3 additional molars per group were processed for the in situ zymography analysis at T0 and T12. Data were statistically analyzed (p<0.05).
Dentin pre-treatment, etching mode, aging and their interactions significantly influenced the bond strength (p T12 (p0.05).
Bonding performances and endogenous enzymatic activity were influenced by pre-treatment with SDF solutions, although the use of Riva Star Aqua showed long term MMPs inhibitory effects comparable to the control groups. Further studies are warranted to validate these results.
The paper presents data on the primary structure of the glycan variants present in human antithrombin (AT) isoforms obtained from a plasma pool. The analysis is conducted on the level of ...glycopeptides gained by tryptic digestion. The glycopeptides were pre-separated by lectin-affinity chromatography and analyzed by means of electrospray ionization–tandem mass spectrometry involving collision-induced dissociation. Variations of the canonical biantennary complex-type structure were present with relative abundances of about 1–5% and most of them were found site-specifically. Core fucosylation was observed at one single glycopeptide only (peptide containing N
155), triantennary glycan structures with two glycopeptides (containing N
155 and N
135). Deficiency of one terminal sialic acid was observed as not site-specific. Fucosylation was not yet reported to be present in human AT from plasma, opposite to recombinant human AT from baby hamster kidney cells, which was reported as fully core fucosylated. In total, the variability in the carbohydrate structure of plasma derived AT appears as being quite limited. This might be of significance in the context of the reported correlation between glycosylation and physiological activity.
