Interventions for replacing missing teeth: denture chewing surface designs in edentulous people

When constructing complete dentures for edentulous patients, ultimately patient satisfaction is key. Complete dentures can be produced with different types of occlusal schemes (chewing surfaces) and it is widely accepted that the occlusal scheme for complete dentures has a direct influence upon their success.

To assess the relative effectiveness of differing occlusal schemes for complete dentures with regard to patient satisfaction. The null hypothesis is that there is no difference in terms of patient satisfaction between different designs of chewing surfaces for complete dentures.

Several electronic databases were searched in order to identify relevant trials: Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (1966 to week 2 April 2004), OLDMEDLINE (1953 to 1965), EMBASE (1980 to week 16 2004),Zetoc (1993 to December 2003), SIGLE (1980 to December 2003), SCI (Science Citation Index) (1945 to 04 April 2004 ). 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 Unpublished data were sought through personal contact with experts in the field.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 or quasi-randomised controlled clinical trials (RCTs), recruiting edentulous adults, and comparing complete dentures produced with different occlusal schemes with regard to patient satisfaction and masticatory function.

The quality assessment of the included trials was undertaken independently and in duplicate by two reviewers based initially on what was written in the articles. Data were 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.

1076 titles and abstracts were identified through the electronic searches. 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 cross-over trial (n = 30), comparing 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 (95% confidence interval 2.04 to 48.96).

There is weak evidence that it may be advantageous, for dentists providing a complete denture service, to prescribe prosthetic posterior teeth with cusps to improve patient satisfaction compared to providing cuspless teeth. However, this conclusion may only be made tentatively until further well conducted trials comparing different occlusal schemes for complete dentures are undertaken.