Simplified vs. Conventional Methods for Complete Denture Fabrication

BACKGROUND: The fabrication of complete dentures traditionally involves a series of complex technical procedures. Those procedures include two impressions for each jaw, the registration of the relationship between the upper teeth and the patient's head and usually two appointments for tooth try-in. However, recent studies have questioned the real need for such complex procedures. Simplified methods could have similar results if compared with conventional ones, and dentures would be delivered faster and with lower costs.

OBJECTIVES: This study aims to compare the effectiveness complete dentures fabricated with a simplified or conventional method.

METHODS: Eighty edentulous patients who requested treatment by maxillary and mandibular complete denture in a public dental clinic inside the University of Sao Paulo - Ribeirão Preto Dental School will be randomly divided into two groups. Group S will receive new dentures fabricated by a simplified method, whereas Group C will received new dentures according to a conventional method. Participants will complete a questionnaire for denture satisfaction and the oral health-related quality of life, 3 and 6 months after treatment. At the same time, a specialist in dental prostheses will evaluate the quality of new dentures.

Complete edentulism can be considered as an important public health problem, particularly in the elderly. The prevalence of edentulism among adults aged 65 or more years is still high in several countries, such as Canada (58%), Saudi Arabia (31-46%), United Kingdom (46%), China (11%) and India (19%). Normative needs of maxillary and mandibular complete dentures in Brazilian elders were estimated to be 16% and 24%, respectively. This way, the epidemiologic aspect reinforces the need for cost-effective methods when treating patients with complete dentures.

The conventional methods for fabrication of complete dentures demand a comprehensive sequence of clinical and laboratorial procedures. Those methods seem to be accepted and taught by most of the American and Brazilian dental schools. However, it has been argued whether they are necessary for the obtainment of adequate dentures. Several approaches were described in attempt to simplify clinical and laboratorial stages, i.e. the fabrication of denture bases directly on casts obtained from irreversible hydrocolloid impressions made in stock trays. Other simplified approaches include the fabrication without facebow transfer, alternative occlusal schemes (i.e. lingualized occlusion) and duplication techniques.

A few recent randomized clinical trials have provided some high level evidence about the efficacy of simplified methods. We ran the following search strategy for PubMed at October 2010:

(overdenture or ((removable or complete) and denture)) and ((techni\* or fabricat\* or simpl\* or tradition\*) or (impression\* or occlus\* or (facebow or face-bow) or remount\* or adjust\*)) and (((randomized controlled trial \[pt\]) OR (controlled clinical trial \[pt\]) OR (randomized \[tiab\]) OR (placebo \[tiab\]) OR (drug therapy \[sh\]) OR (randomly \[tiab\]) OR (trial \[tiab\]) OR (groups \[tiab\])) AND (humans \[mh\]))

After reading the 470 titles and abstracts, and examining possible reports of randomized clinical trials, only two studies that attempted to evaluate simplified methods for denture fabrication were found.

One of the studies compared a simplified and a conventional method for complete denture fabrication by a parallel arms trial. The difference between the methods was the use of a second impression, facebow transfer and remount by the conventional approach. No significant difference between the groups was found for the outcome variables tested - denture quality and patient satisfaction. The other trial compared the relative efficacy of complete dentures fabricated according to two occlusal concepts, by means of a crossover design. A more complex method employed a facebow transfer with recordings of condylar inclination, gothic arch tracing and bilateral balanced occlusion. The simplified technique used no facebow transfer, manual technique for the record of centric occlusion and canine guidance. Denture satisfaction was not influenced by the fabrication method.

The current evidence raises doubt about the relevance of some procedures involved in the fabrication of complete dentures. Despite the high quality of the previously cited trials, further studies could use a more pragmatically approach such as testing methods in public health patients. Moreover, data from additional studies could be summarized in the future by means of meta-analysis and thus evidence would be stronger. In summary, such studies may provide support to either:

1. Improve access of the edentulous patients to complete denture treatment by lowering costs and complexity;
2. Reinforce the importance of technical procedures during denture fabrication.

OBJECTIVES

To compare complete dentures fabricated with a simplified technique and conventional prostheses for the rehabilitation of edentulous patients, after 3 and 6 months of wearing.

The null hypothesis will be that mean values of oral health-related quality of life for pairs of dentures fabricated by the simplified and the conventional dentures are similar. Similar secondary hypotheses will be considered for the secondary variables.

Eligibility Criteria:
Inclusion Criteria:

* Completely edentulous for at least 1 year
* Patients requesting new maxillary and mandibular complete dentures
* Mental receptiveness
* Good understanding of spoken Portuguese

Exclusion Criteria:

* Debilitating systemic diseases
* Pathologic changes of residual edentulous ridges
* Dysfunctional disorders of the masticatory system