Protesis Total

Braz Dent J (2005) 16(2): 135-139

Acrylic resin handle for final impression

135 ISSN 0103-6440

Modified Functional Impression Technique for Complete Dentures
Alexandre MALACHIAS Helena de Freitas Oliveira PARANHOS Cláudia Helena Lovato da SILVA Valdir Antônio MUGLIA Carla MORETO

Department of Dental Materials and Prosthodontics, Faculty of Dentistry of Ribeirão Preto, University ofSão Paulo, Ribeirão Preto, SP, Brazil

This report describes the use of a removable acrylic resin tray handle that can be easily attached to custom impression trays to produce an improved peripheral sealing zone. This device can be indicated to develop functional impressions for complete dentures using the patient-conducted muscular motion technique. In upper trays, the handle is fixed in themidline with acrylic resin, while in lower trays the centrally positioned handle is removed before border molding. This removable handle allows patient’s suction and free tongue movements. Final impression is carried out in two stages: peripheral sealing (low fusion compound) and recording of the main supporting region of the denture (zinc oxide and eugenol paste). All border records are obtained fromthe patient’s own movements (handle suction and tongue motion). The removable handle is simple to use, is reusable, can be adapted to any individual acrylic resin trays and allows accurate registration of the peripheral sealing zone (border tissues). Key Words: complete dentures, functional final impressions, removable anterior tray handle.

INTRODUCTION
Stability of complete lower dentureshas challenged dentists and patients alike. In particular, “flat lower ridge” is associated with difficulties in providing successful dentures (1,2). Resorption rates vary from patient to patient and some authors have postulated several etiological factors related to residual (alveolar) ridge resorption, ranging from localized pressure to systemic factors (3). Making accurate final impression forcomplete dentures is a multistage process that involves a preliminary impression, a customized final impression tray and a final border impression (4,5). It is important to thoroughly examine the patient’s mouth and select the most appropriate impression technique (1,6). A major requirement for final impression of complete dentures is to develop the peripheral contours to accommodate normal muscularfunction and to ensure peripheral adaptation without allowing air penetration between the

future denture base and the mucous membrane (7). During the impression procedure, muscular zone record can be achieved by either the dentist or the patient or both. Many dentists pull on the patient’s lips and cheeks to register the border areas (tissues surrounding the dentures) (8), which usuallyprovides satisfactory border sealing zone (labial and buccal flanges). In the technique where muscular zone record is obtained with the patient’s help, the patient is asked to make specific muscular movements of the lips, cheeks, tongue and jaws (open/closure and lateral). The use of an individual tray is necessary for this technique. The borders of this tray should be established in such a way that thepatient’s muscular movements are free from them during the impression procedure (9,10). This article describes the construction and use of a removable functional acrylic resin handle that can be attached to custom impression trays, allowing an excellent peripheral sealing zone impression using a patientconducted muscular and jaw motion technique.

Correspondence: Profa. Dra. Helena de FreitasOliveira Paranhos, Departamento de Materiais Dentários e Prótese, Faculdade de Odontologia de Ribeirão Preto, USP, Avenida do Café, S/N, 14040-904 Ribeirão Preto, SP, Brasil. Tel: +55-16-3602-4006. e-mail: helenpar@forp.usp.br

Braz Dent J 16(2) 2005

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A. Malachias et al.

MATERIAL AND METHODS
Functional tray handles can be used with any individual acrylic resin trays. These...