To investigate opinions on, and current use of lining materials prior to the placement of posterior resin composite restorations by general dental practitioners (GDPs) in the UK. A further objective was to investigate aspects of posterior resin composite restoration placement techniques employed by UK GDPs.
A questionnaire was devised to gain the information sought. It was sent to 500 UK dentists, chosen at random from the register of the General Dental Council.
Three hundred and fifty four replies were received, which gave a response rate of 71%. Eighty two percent of respondents reported placing lining materials in deep cavities to be restored with resin composite. Regarding moderately deep cavities, half of the respondents indicated a preference to place a lining material, whilst 44% were not sure if a lining was required. The remaining 6% did not respond to the question. Of the respondents, 39% reported that they did not place lining materials in shallow cavities. Regarding techniques for posterior resin composite placement, two-step etch and rinse systems were the most common adhesive bonding systems used (60%). The majority of respondents (80%) reported not using rubber dam when restoring posterior teeth with resin composite.
There was considerable confusion about the need to place a lining prior to resin composite restorations placement in moderate depth and shallow cavities, whilst most favoured the placement of a lining in deep posterior cavities. The majority of GDPs may not routinely use rubber dam for the placement of posterior resin composite restorations.
Decision making and operative techniques for cavity linings under posterior composite restorations in moderately deep and deep cavities is contentious among dentists, resulting in a need to generate more convincing, practice-relevant data on the use of lining materials to inform the dental profession.
Posterior composite restorative materials and adhesive bonding technologies have evolved over many decades . The materials and adhesive techniques currently available are greatly improved in comparison to early formulations. Concerns over the longevity of posterior resin composites have reduced as clinical studies suggest that this now matches that of restorations of dental amalgam . Contemporary literature would suggest an increasing trend towards the use of resin composites in the restoration of posterior teeth, and there is evidence that dental schools, both in the UK and elsewhere around the world, now teaching resin composites as the material of choice for the restoration of posterior teeth . However, variation has been reported in the teaching of the use of linings 1
1 The term lining in the present paper includes liners and bases.
prior to the placement of posterior resin composites . For decades, the restorative management of caries involved the placement of a lining on the floor and, when present, axial walls of the cavity . The placement of a lining was proposed for several reasons: to reduce the number of viable bacteria remaining close to the pulp, to induce development of reactionary/reparative dentine, to possibly remineralize remaining demineralized hard tissues, to isolate the pulp against thermal and electric conduction, to protect pulpal cells against chemical irritants such as methacrylates from adhesives and to prevent the effects of restoration leakage on the pulp. However, the development of new restorative materials and the emerging concept of minimum intervention dentistry, including changes in the perceived need to remove all caries, i.e., removing only infected dentine, leaving affected dentine , have raised doubts regarding the need for a cavity lining to maintain pulpal vitality .
To date, little information, other than anecdotal, subjective comments, exists regarding general dental practitioners’ use of dental lining materials prior to the placement of posterior resin composite restorations. No such information exists for the UK. It was therefore considered important to investigate this important aspect of everyday restorative dentistry.
The aim of this study was to investigate opinions on, and current use of lining materials prior to the placement of posterior resin composite restorations by GDPs in the UK. A further aim was to investigate aspects of posterior resin composite restoration placement techniques employed by UK GDPs.