The management of patents who present with the partial loss of teeth is a common task for dentists and has been so for many years. The aim of this Cochrane review is to assess the effects of different prostheses for the treatment of partially absent dentition in terms of the following outcomes: long-term success, function, morbidity and patient satisfaction.

Searches of the Cochrane Oral Health Group’s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline  and Embase databases were conducted with no restrictions regarding language or date of publication.  The authors included randomized controlled trials (RCTs) comparing different methods (including the design and materials used) of treating partial edentulism, with clinically relevant outcomes. Trials that reported only surrogate outcomes, such as plaque accumulation or gingival volume, were excluded.

Two review authors independently carried out the screening of eligible studies, assessment of dimensions of quality of trials, and data extraction. Results were expressed as mean differences for continuous data, risk ratios for dichotomous outcomes, and hazard ratios with 95% confidence intervals for time-to-event data.

Twenty-one trials met the inclusion criteria for this review. Of these 24% were assessed as being at high risk of bias and the remainder were at unclear risk of bias. The clinical heterogeneity among the included studies precluded any attempt at meta-analysis.

There was insufficient evidence to determine whether one type of removable dental prosthesis (RDP) was better or worse than another.

With fixed dental prostheses (FDPs), there was no evidence that high gold alloys are better or worse than other alloys, northat gold alloys or frameworks are better or worse than titanium.

There is insufficient evidence to determine whether zirconia is better or worse that other FDP materials, that ceramic abutments are better or worse than titanium, or that one cement was better or worse than another in retaining FDPs.

There is insufficient evidence to determine the relative effectiveness of FDPs and RDPs in patients with shortened dental arch or to determine the relative advantages of implant supported FDPs versus tooth/implant supported FDPs

The authors concluded

Based on trials meeting the inclusion criteria for this review, there is insufficient evidence to recommend a particular method of tooth replacement for partially edentulous patients.

In their conclusions the authors discuss the implications for research highlighting that, at present the majority of clinical reports for this patient population is found:-

1. in non-randomized studies,
2. in studies not comparing different prostheses, and
3. in settings which may not be representative of standard practice settings.

Consequently they call for more well designed and conducted RCTs ideally with  follow-up periods long enough to enable the collection of data on comfort, function, appearance, and duration of survival of different types of prosthodontic devices. They also  point to the need for a greater understanding of the bias impact associated with non-random study inference.

As dental implants have become increasingly popular method of treatment they note that:-

while it is appropriate that research consider the role of implants in management of partial tooth loss, there is a need for comparative research for conventional tooth supported prostheses as well as devices, to determine whether these may have important benefits for some groups of patients.

Abt E, Carr AB, Worthington HV. Interventions for replacing missing teeth: partially absent dentition. Cochrane Database of Systematic Reviews 2012, Issue 2. Art. No.: CD003814. DOI: 10.1002/14651858.CD003814.pub2.