A simplified technique to fabricate complete dentures from the previous prosthesis duplication for elderly patients

Introduction: The time required for the complete dentures confection may be a limiting factor in the treatment of geriatric patients since these patients have age-related systemic conditions and morbidities that limit their mobility. Also, the elderly ability to adapt to a new prosthesis Research, Society and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8620 2 with very different characteristics from the existing ones can be difficult. Methodology: This present study aims to describe a simplified technique to fabricate the complete dentures in two visits by duplicating the patient existent prosthesis, with the teeth area confectioned in wax and the other parts made of acrylic resin. The technique consists of using the replica of the patient's existent prosthesis to record the maxillomandibular relations and as a vehicle for obtaining the functional cast. Results: This technique showed the improvement of the esthetic factors, an increase of the occlusal vertical dimension, and lip support when compared to the patient’s previous prosthesis. Conclusion: This technique allows the reduction of clinical steps and provides the patients with an easier adaptation of the new prosthesis.


Introduction
The traditional technique to rehabilitate with the conventional complete denture prosthesis is known by its methodological complexity and involves various clinical sessions (Carreiro et al., 2016). Conventionally, it consists at the following clinical steps: primary impression, functional impression, maxillomandibular relations and interocclusal records, proof of mounting, placement and post-placement care (Zarb et al., 2013). Thus, the time required for the complete dentures confection may be a limiting factor in the treatment of geriatric patients, since these patients have age-related systemic conditions and morbidities that limit their mobility (Müller, 2014).
Another important aspect at the elderly rehabilitation is the adaptation to the new complete prosthesis (Kamalakidis et al., 2016). In this population, the neuroplasticity necessary to learn new motor abilities or to adapt to the existent arrangements can be compromised (Luraschi et al., 2013). Consequently, the elderly ability to adapt to a new prosthesis with very different characteristics from the existing ones can be difficult, resulting in frustration for the patient and the dentist as well (Muller & Hasse-Sander., 1993).
In order to simplify the steps for complete denture fabrication, abbreviated techniques emerged, consisting in the elimination or simplification of some clinical and/or laboratorial phases of the traditional techniques (Cunha et al., 2013;6. Heydecke et al., 2008;Paulino et al., 2015;Vecchia et al., 2014). 5-8 One of the time-reducing ways is the previous prosthesis duplication technique. Consisting to obtain the functional impression and interocclusal record from a replica of the previous prosthesis with self (Kulkarni & Pawar, 2017) or light-curing acrylic resin. 10 This technique is indicated in the case where the prosthesis replacement is necessary due to the wear, fractures or color alterations resulted by its long period of use Research, Society and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8620 4 (Gorman & O'Sullivan,, 2006). However, when major alterations are necessary, the adjustment during the maxillomandibular register is difficult due to the replica being fabricated completely in acrylic resin.
Aiming to facilitate the alterations on the maxillomandibular relation register, the technique proposed in this article consists of fabricating the replica with wax inserting 07 at the area corresponding to the artificial teeth and has only the base in acrylic resin. The wax easily allows for the addition or removal of material at the artificial teeth area during the esthetic adjustment and the maxillomandibular relation; moreover, it facilitates the artificial teeth arrangement by the dental prosthesis technicians.

Methodology
The study proposes to present a description of the technique demonstrating a method for making a simplified total prosthesis using the technique of duplicating the old prosthesis through a clinical case report (case study) with descriptive, exploratory purposes, with a qualitative approach, according to Pereira, Shitsuka, Parreira, and Shitsuka (2018).
Thus, according to the knowledge from clinical practice and based on the scientific literature on the topic addressed, and considering the different possibilities of conducting the case presented, a simplified technique was proposed, which consists of using a replica of the prosthesis in use by the patient as an individual tray and registration of maxillomandibular relationships, in which the differential of our technique of the others already described in the literature is in fabricating the replica with wax insert 07 at the area corresponding to the artificial teeth and has only the base in acrylic resin.
In which the wax easily allows for the addition or removal of material at the artificial teeth area during the esthetic adjustment and the maxillomandibular relation. Moreover, it facilitates the artificial teeth arrangement by the dental prosthesis technicians. In addition to making the prosthesis will occur in two clinical consultations, favoring clinical time and adaptation patient's new prosthesis.

Technique
First session: 1. Disinfection of the patient's previous prosthesis with 2.5% sodium hypochlorite (Asfer; Chemical Industry) during 10 minutes; Research, Society and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4 9. When necessary, obtain the peripheral impression with low-fusing modelling compound stick (Lysanda), closed-mouth functional impression with zinc and eugenol paste or an elastomeric material (Lysanda), using the duplicated prosthesis as the custom tray ( Figure   1H); 10. Selection of the artificial teeth (Biolux, VIPI odontological products), and artificial gingival color. Research, Society and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8620 In image 1A, it is possible to observe the wax inserted in the duplication mold leaving the space for insertion of the acrylic resin. Image B with duplication completed, area of the teeth in wax, and base of the duplication in acrylic resin. Image C patient with old prosthesis intraoral view compared to duplication in image D. Image E shows a lack of lip support and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8620 7 decrease in the height of the vertical dimension of occlusion, requiring adjustment and insertion of wax observed in images F and G, followed by a functional impression of the duplication in occlusion observed in image H.

Laboratorial procedures:
1. Confection of the functional cast and articulator mounting using the register ( Figure 2A Image 2A showing duplication of the total prosthesis after being fitted to an articulator Research, Society and Development, v. 9, n. 10, e3169108620, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i10.8620 8 in which the necessary parameters for fitting the artificial teeth shown in image B can be observed. Images C and E showing old prosthesis with incisal wear and lower vestibular volume compared to images D and F that present the new prosthesis resulting from duplication, presenting better volume and vestibular height.

Second and last session:
Placement of the new prosthesis (Figure 3 A-D) and adjustments. Image 3A and C of the patient with the old total prosthesis with impaired lip support and decreased vertical dimension of occlusion, observe the wear of the teeth of the old prosthesis. Images B and D patient after the installation of the new total prosthesis presented adequate lip support and vertical dimension of occlusion with aesthetic improvement.