Prosthetic posterior teeth with cusps may improve patient satisfaction with complete dentures

The Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials, Medline, OLDMedline, Embase, Zetoc (Zetoc provides access to the British Library's electronic table of contents of approx. 20,000 current journals and 16,000 conference proceedings published per year. The database covers 1993 to date and is updated daily. It includes an e-mail alert service to enable you to keep up-to-date with relevant new articles and papers), System for Information on Grey Literature in Europe (SIGLE) (SIGLE is a bibliographic database covering European non-conventional (or 'grey') literature in the fields of pure and applied science and technology, economics, social sciences and humanities), and the Science Citation Index were used to source studies. Reference lists of identified, relevant trials and review articles were scanned. Unpublished data were sought through personal contact with experts in the field. There was no language restriction.

Randomised controlled trials (RCT) or quasi-RCT were selected that recruited edentulous adults and compared complete dentures with different occlusal schemes, with regard to patient satisfaction and masticatory function.

The quality assessment of included trials was undertaken independently and in duplicate by two reviewers. Data were also extracted by two reviewers independently. Disagreements were discussed and a third reviewer consulted as necessary. Authors were contacted for clarification or missing information. Data were excluded until further clarification if agreement could not be reached.

Thirteen trials were thought to be potentially relevant. Ten of these studies were subsequently excluded following further analysis. Two trials require further information from the author before being considered eligible for inclusion. Only one crossover trial (n=30), which compared lingualised teeth and zero-degree teeth, fully met the review's inclusion criteria. Twenty patients preferred the lingualised denture, five the zero-degree denture and five patients had no preference. There was a statistically significant difference in favour of the lingualised denture with an odds ratio of 10.00 (95% confidence interval, 2.04-48.96).

There is weak evidence that it may be advantageous for dentists who provide a complete denture service to prescribe prosthetic posterior teeth with cusps, rather than cuspless teeth, to improve patient satisfaction. This conclusion may only be made tentatively until further, well-conducted trials are undertaken that compare different occlusal schemes for complete dentures.