The immediate bonding effectiveness of contemporary adhesives is quite favorable, regardless of the approach used. In the long term, the bonding effectiveness of some adhesives drops dramatically, whereas the bond strengths of other adhesives are more stable. This review examines the fundamental processes that cause the adhesion of biomaterials to enamel and dentin to degrade with time. Non-carious class V clinical trials remain the ultimate test method for the assessment of bonding effectiveness, but in addition to being high-cost, they are time- and labor-consuming, and they provide little information on the true cause of clinical failure. Therefore, several laboratory protocols were developed to predict bond durability. This paper critically appraises methodologies that focus on chemical degradation patterns of hydrolysis and elution of interface components, as well as mechanically oriented test set-ups, such as fatigue and fracture toughness measurements. A correlation of in vitro and in vivo data revealed that, currently, the most validated method to assess adhesion durability involves aging of micro-specimens of biomaterials bonded to either enamel or dentin. After about 3 months, all classes of adhesives exhibited mechanical and morphological evidence of degradation that resembles in vivo aging effects. A comparison of contemporary adhesives revealed that the three-step etch-and-rinse adhesives remain the 'gold standard' in terms of durability. Any kind of simplification in the clinical application procedure results in loss of bonding effectiveness. Only the two-step self-etch adhesives approach the gold standard and do have some additional clinical benefits.

http://www.endoexperience.com/documents/DeMunketalDurabiltyofadhesionJDR.pdf

A Critical Review of the Durability of Adhesion to Tooth Tissue: Methods and Results

Bonding to tooth tissue can be achieved through an "etch&rinse," "self-etch" or "glass-ionomer" approach. In this paper, the basic bonding mechanism to enamel and dentin of these three approaches is demonstrated by means of ultramorphological and chemical characterization of tooth-biomaterial interfacial interactions. Furthermore, bond-strength testing and measurement of marginal-sealing effectiveness (the two most commonly employed methodologies to determine "bonding effectiveness" in the laboratory) are evaluated upon their value and relevance in predicting clinical performance. A new dynamic methodology to test biomaterial-tooth bonds in a fatigue mode is introduced with a recently developed micro-rotary fatigue-testing device. Eventually, today's adhesives will be critically weighted upon their performance in diverse laboratory studies and clinical trials. Special attention has been given to the benefits/drawbacks of an etch&rinse versus a self-etch approach and the long-term performance of these adhesives. Correlating data gathered in the laboratory with clinical results clearly showed that laboratory research CAN predict clinical effectiveness. Although there is a tendency to simplify bonding procedures, the data presented confirm that conventional three-step etch&rinse adhesives still perform most favorably and are most reliable in the long-term. Nevertheless, a self-etch approach may have the best future perspective. Clinically, when adhesives no longer require an "etch&rinse" step, the application time, and probably more importantly, the technique-sensitivity are substantially reduced. Especially "mild," two-step self-etch adhesives that bond through a combined micromechanical and chemical interaction with tooth tissue closely approach conventional three-step systems in bonding performance.

Buonocore memorial lecture, adhesion to enamel and dentin: current status and future challenges

Systematic review of the chemical composition of contemporary dental adhesives

Dental adhesion review: Aging and stability of the bonded interface

http://webdelprofesor.ula.ve/odontologia/robertramirez/PDF/1.pdf

State of the art of self-etch adhesives

TEM evaluation of self-etching adhesives resin-dentin interfaces

Seven-Year Clinical Effectiveness of Two 3-step Etch-and-Rinse Adhesives

Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)-silver complexes (Met or His-Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy. At first the complexes were characterized using nuclear magnetic resonance (NMR), and amino acid-Ag complex-loaded Mont (amino acid-Ag-Mont) were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of these materials in dental acrylic resin was then investigated by bacterial growth measurement using a spectrophotometer. As controls, commercially available silver-loaded zeolite and silver-zirconium phosphate were also tested. Dental acrylic resin incorporating His-Ag-Mont strongly inhibited Streptococcus mutans growth. This was explained by the fact that His-Ag complex revealed the highest amounts of silver ions in the presence of chloride. The structure of the amino acid-Ag complexes affected the silver ion presence in chloride and the antibacterial efficacy. His-Ag-Mont might be used as antibacterial agents for dental materials.

/pdf/antibacterial-effect-of-amino-acid-silver-complex-loaded-14iz375diq.pdf

Antibacterial Effect of Amino Acid-Silver Complex Loaded Montmorillonite Incorporated in Dental Acrylic Resin

Background: Periopathogens and cariogenic species survive more than 48 hours on toothbrushes even under dry storage. This study examined a decontamination of toothbrushes by means of the bactericidal effect of different toothpastes or a special coating of the tufts. Methods: Eight untreated periodontitis patients were professionally brushed, using a new toothbrush per quadrant and 3 different toothpastes containing either amine/stannous fluoride (AmF/SnF2), amine fluoride (AmF), or a mild surfactant as major antibacterial component (excipient), or no paste (C). The brushes were rinsed and stored dry at room temperature. At different time intervals, 4 tufts per toothbrush were processed for selective and non-selective culturing procedures. The protocol was repeated comparing AmF/SnF2 and C with 2 toothbrushes with coated tufts (coat1 and coat2). Results: At baseline, C brushes (n = 16) harbored 10 7 , 10 8 , and 10 6 colony forming units (CFU) of aerobic, anaerobic, and black pigmented species, respectively. After 24 hours 10 6 CFU of aerobic and anaerobic species could still be cultured from 14 of the 16 brushes. Black-pigmented species remained detectable up to 4 hours; detection frequencies for Fusobacterium nucleatum and Streptococcus mutans at 24 hours were 5/16. With AmF/SnF2 and AmF toothpaste the number of adhering bacteria was already 2 log lower at baseline (P 0.20), and clearly inferior to the AmF/SnF2 paste (P 10 5 CFU. Conclusions: Toothpastes can significantly reduce contamination of toothbrushes, but their bactericidal activity is dependent on their composition. Coated tufts failed to limit the bacterial contamination. J Periodontol 2003;74:312-322.

Bart Van Meerbeek

Papers

TEM evaluation of self-etching adhesives resin-dentin interfaces

Seven-Year Clinical Effectiveness of Two 3-step Etch-and-Rinse Adhesives

Antibacterial Effect of Amino Acid-Silver Complex Loaded Montmorillonite Incorporated in Dental Acrylic Resin

Can Toothpaste or a Toothbrush with Antibacterial Tufts Prevent Toothbrush

Experimental resin-modified calcium-silicate cement containing N-(2-hydroxyethyl) acrylamide monomer for pulp tissue engineering.