There are numerous dentine bonding agents c u r r e n t l y on the market, the majority of which adhere by means of infiltration of a hydrophilic p o l y m e r i z a b l e diacrylate into dentinal collagen exposed by acid treatment. The purpose of the present study was to evaluate the clinical performance of one such product, EBS dentine bonding, in nonundercut caries-free cervical lesions. Forty cavities were restored in eight patients of mean age 53 years. The manufacturer's instructions were followed, which involved essentially etching the enamel and dentine for 20 seconds with 32 per cent phosphoric acid, application and evaporation of EBS Primer, followed by placement and curing of EBS Bond, and restoring the cavity with Pertac II (ESPE) hybrid resin composite. Restorations were photographed at base line and one year for evaluation of marginal discolouration on a continuous linear rating scale. A t six months, one patient with four restorations was not available; the remaining 36 restorations were all present. At one year, one restoration was missing, giving a cumulative retention rate of over 97 per cent. One of the 36 restorations exhibited very mild marginal discolouration.Key words: Dental bonding, dentine bonding agents, acid etching, tooth abrasion therapy.(Received for publication October 1999. Revised January 2000. Accepted February 2000 did not occur in practice and clinical failure rates we r e high in non-undercut non-carious cervical lesions. Following the work of Nakabayashi et al., 4 almost all the current dentine bonding agents achieve a d h e s i o n mechanically by infiltration into the dentinal collagen, exposed by acid treatment of the dentine, by a hydrophilic polymerizable monomer (a 'primer'). The infiltrated collagen is termed the ' hy b ri d ' or ' r e s i n -r e i n f o r c e d ' l aye r , and the methacrylate groups on its surface can then bond chemically to the subsequently placed resin composite, assisted by an intermediate layer of 'adhesive' or 'bond' which acts as a wetting agent.2 Commercial products commonly employ simultaneous enamel and dentine etching, in order to enhance the efficiency of the bonding procedure.One such material is EBS (ESPE Dental AG, Seefeld, Germany).The etch consists of 32 per cent phosphoric acid, the Primer is an aqueous solution of hy d r ox ye t hy l m e t h a c ry l ate (HEMA) and m e t h a c ryl magnesium chelate (MMC), and the Bond is malonic acid alkyl methacrylate (MAM) and bis-methacrylates. There are limited published data on EBS. A tensile bond strength of 9.8 MPa, 5 and shear bond strengths of 17.2 MPa5 and 33.6 MPa, 6 have been reported. In a clinical study, van Dijken 7 reported a zero one year loss rate of zero for Pertac (ESPE Dental AG, Seefeld, Germany) resin composite restorations bonded with EBS in nonc a ri o u s c e rvical lesions (NCCL). H owe ve r , t h i s appears to be the only study of this type available.The purpose of the present study was to evaluate the clinical performance, with respect to retention and marg...