Single-bottle adhesives behave as permeable membranes after polymerization. I. In vivo evidence F.R.

Taya, , R. Frankenbergerb, I. Krejcic, S. Bouillaguetc, D.H. Pashleyd, R.M. Carvalhoe and C.N.S. Laia aFaculty of Dentistry, Pediatric Dentistry and Orthodontics, University of Hong Kong, 34 Hospital Road, Hong Kong bPoliclinic for Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Germany cDepartment of Cariology, Endodontics and Pediatric Dentistry, School of Dental Medicine, University of Geneva, Switzerland dDepartment of Oral Biology and Maxillofacial Pathology, Medical College of Georgia, Augusta, GA, USA eDepartment of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil Received 16 June 2003; revised 8 October 2003; accepted 28 April 2004. Available online 4 August 2004.

Summary

Objectives:

This study tested the hypothesis that single-bottle total-etch adhesives are effective in reducing dentine permeability under in vivo conditions. Methods: Crown preparations on vital human teeth were performed under local analgesia as part of the treatment plan for prosthetic rehabilitation. Four single-bottle adhesives (Single Bond, 3M ESPE; Excite DSC, Ivoclar Vivadent; Prime and Bond NT Dual-Cure, Dentsply DeTrey and One-Step, Bisco Inc.) were applied to the cut dentine after acid-etching. Polyvinyl siloxane impressions were taken, using an ultra-low viscosity impression material, of the smear layer-covered dentine before applying the adhesives to deep vital dentine, and after adhesive placement. Additional impressions were taken of the adhesive-sealed dentine following the removal of the provisional prostheses after a 710 day period. Epoxy resin replicas of the crown preparations were examined with scanning electron microscopy to evaluate the extent of dentinal fluid transudation during pre-bonded, immediately bonded and post-bonded periods. Results: Dentinal fluid transudation from localised areas that were close to the dental pulp was universally observed from all epoxy resin replicas, irrespective of the adhesive employed. The transudation of dentinal fluid from the control smear layer-covered dentine of each crown preparation was comparatively mild when compared to the extent that was observed after total-etching and application of the single-bottle adhesive. Dentinal fluid droplets were specifically located over the surface of the adhesive layer. Continuous transudation of dentinal fluid occurred even after the removal of the provisional prostheses, and was considerably more profuse in subjects who opted for the fitting of the permanent prostheses without the use of a local anaesthetic solution.

Conclusion:

Single-bottle adhesives, because of their lack of a comparatively more hydrophobic bonding resin layer, behave as permeable membranes after polymerisation. They permit the continuous transudation of dentinal fluid and do not provide a hermetic seal in vital deep dentine. Although the relatively slow rate of diffusion of dentinal fluid is unlikely to result in post-operative cold sensitivity, it may interfere with the optimal polymerisation of dual-cured or auto-cured composites or resin cements in both direct and indirect restorations.

Keywords: Total-etch; Two-step; Vital dentine; Dentinal fluid; Permeability