Nebojša Krunić,
Zorica Ajduković,
Saša Stanković

DENTAL CLINIC, NIŠ, DEPARTMENT OF DENTAL PROSTHETICS

IIntroduction  

The basic task of the partial flat denture retention system is to provide stable lying on the jaw both in state of stillness and function, to participate in stabilization, but to meet aesthetic conditions as well. Simple to make the wire hooks are the most frequent form of retention of such dentures although they do not meet the up-to-date prosthetic principles.¹ Unfavourable factors make their presence felt when maximum partial flat denture is indicated, particularly when few teeth have been left in the frontal region. Namely, there is no need to point out of what significance, in addition to the biological moment, that is, its maximum accommodation in the mounts aesthetic is as well. ²

The purpose of this paper is to report on one of the possibilities of aesthetic solutions of the subtotal anodontia by means of a flat denture. 

Material and method 

Used as the elements for the partial flat denture were attachments (interdental crossbars  Plastdent Ni{) consisting of plastic patrix and metal matrix (Figure 1). First, a fixed construction is made that may consist of metal-ceramic or faceted crowns linked into a block. Teeth preparation, anatomic impression as well as crowns modelling were done in a standard way. Upon the distal surfaces of the end crowns patrices are fixed on both sides in a way that there remains enough space for the matrix and artificial acrylic teeth (Figure 2). For such cases of anodontia (a small number of teeth in the frontal region) previous modification of the patrix shall be done by shortening to 5 mm. The patrix should be located against the gingiva so as to touch it linearly, without pressure. Thus, creation of empty spaces between mucous membrane and the crossbar is prevented. Upon casting and processing the crowns are tested in the mouth and one should get down to making the partial flat denture anatomic impression. After reconstructing the interjaws relations and testing the teeth positioned, preparation for acrylate polymerisation in the mouth shall be carried out. Prior to prepolymerisation, enough space shall be made in the denture basis for the matrix that is fixed to the denture saddle acrylate by means of special extensions. The matrix wings shall remain free and may be activated as needed.

Fig. 1. Attachments (Interdental Crossbars)	Fig. 2. Cast Patrices with Metal-Ceramic Crowns

When the denture is finally completed one shall get down to cementing the artificial crowns always together with the denture (Figure 3). Previously, visible surfaces of the interdental crossbars should be isolated by means of vase-line so as to avoid fixing of the denture to the crowns. Then, surplused cement should easily be removed while the denture is present in the mouth because its removal and repeated applica-tion are not recommended during the final cement bonding process. The patient himself should be advised not to remove the denture, and the first subsequent visit should be scheduled for the next day when any possibly remaining cement will be definitely removed. Other controls should be carried out according to the usual regime.

Fig. 3. Final Appearance of the Fixed-Mobile Denture

 Results and discussion 

The results obtained point to the possibility of resolving the subtotal anodontia by means of the partial flat denture without using hooks as standard retention elements. These attachments provide good and aesthetic retention accomplished on the buckle principle, that is, by mechanical friction of the contacting surfaces of the matrix and the patrix.³ Tightening the matrix wings against the patrix sides excessive move-ment, which improves the denture stabilization as well. ⁴ Vertical denture settling is minimal so that the pressure division between the dental and gingival part of the denture is approximately equal. There are far less subjective troubles then with the partial flat denture with classical hooks, also probably due to the fact that the chewing pressure is closer to that physiological by means of which approximate functional unity between the denture and the remaining teeth is accomplished. ⁵ Placing the patrix against the gingiva, mucous membrane hypertrophy is pre-vented and statically is more favourable because it coincides with the Suvin assertions.6 The patients more readily and easily accept such dentures. One of the advantages of this method of work is very low price of these attachments that are simple to build-in. Should the retention relax in time, it may be improved by activating elastic matrix wings and in case of fracture may be simply replaced. 

Conclusion

 Thus made partial flat dentures represent a good therapeutic means particularly in the case of few teeth in the frontal region. Linking the remaining teeth into a block a good periodontal prophylaxis is accomplished as well. In addition to the aesthetic effect, certain dental load can also be accomplished, which at the same time improves the mastication effect. Due to its simplicity and in cases when metal dentures cannot be

Adress for correspondence:

Ass. dr Nebojša Krunić, D.D.S., MSD, Ph. D
Filipa Vićnjića Street 7/6, 18000 Nis
Tel. 018/42-424

E-mail: krunic@junis.ni.ac.yu

• Copyright © 2004 by The Editorial Council of The Acta Stomatologica Naissi