Immediate Complete Denture Prosthetics

The demand for lower-cost treatment solutions is on the rise.

By Robert Kreyer, CDT

Today’s uncertain economic climate coupled with a larger aging population has produced a surge in demand for immediate complete dentures. This treatment is both one of the most challenging and rewarding in removable prosthodontics. There are two methods for providing clinical and technical treatment for complete immediate denture prosthetics—one is to use the immediate denture as an interim or provisional prosthesis and the other is to treat the immediate complete denture as the definitive prosthesis and then reline after surgical healing and ridge resorption.

The first method allows fabrication of the definitive denture at a later date after surgical healing, enabling the technician to reset denture teeth according to ridge resorption and improve anterior esthetics. This approach is optimal, but dental professionals are not always presented with optimal situations or expectations. When financial considerations are paramount, the second option usually best meets the patient’s budget and treatment outcome expectations. Other indications for immediate complete denture prosthetics as an interim or provisional prosthesis include precision restorations such as implant-retained and -supported prosthetics.

With immediate dentures, it is very common to decrease labial flare, straighten teeth, and increase vertical dimension, thus improving a patient’s esthetic smile immediately upon insertion of the prosthesis. The clinician and technician have the opportunity to improve existing anterior esthetics with posterior function while still meeting a patient’s financial expectations or restrictions.

Treatment protocol

In this case, a 76-year-old woman presented with the need for a maxillary complete denture. Due to financial constraints, this immediate prosthesis was treated as a definitive complete denture to be relined after surgical healing and ridge resorption resulting from prosthetic surgery.

Three technical factors were critical to success in this case:

• Pre-prosthetic cast surgery and ridge reduction
• Labial and peripheral border extensions
• Tooth placement for improving esthetics and function

A cast analysis of the patient’s initial dental condition (Figure 1) revealed the challenges this case presented. Teeth Nos. 5 through 12 were to be conventionally extracted while repositioning denture teeth in a more esthetic and functional position. During the planning stages the clinician communicated his desire to reduce the maxillary anterior labial flare of teeth Nos. 7 through 10 by 1.5 mm and to raise the incisal edges by 1.5 mm. According to an analysis of the posterior residual ridge in centric relation, the patient’s left and right sides were in a cross-bite relationship resulting from residual ridge resorption. When setting the denture teeth in centric occlusion a normal posterior occlusal relationship was achieved on the left side and a modified cross-bite on the right side.

The labial flare or proclination was evident (Figure 2), and the cross-bite was apparent according to cast analysis and occlusal contacts in the second molar area. Because there were only three teeth to extract on the left side (Figure 3), pre-prosthetic model surgery was performed by removing and socketing each tooth. The ridge was reduced labially by 1 mm to 2 mm, depending on the length of the tooth roots. The author then contoured denture teeth and set each into a prepared socket according to the clinician’s instructions and desired outcome (Figure 4).

Although mandibular left posteriors were missing, a prosthesis was not prescribed, so denture teeth were set to create an ideal plane of occlusion using the left retromolar pad (two-thirds height) as a posterior anatomical landmark and the distal-incisal marginal ridge of the left canine as a guide (Figure 5 ). Based on cast analysis, the relationship of the second molar to the crest of ridge could be understood according to the Hamular notch line on the medial side and the ridge crest line on the lateral or buccal side of the ridge crest. These two lines denoted proper biomechanical placement of the posterior teeth (Figure 6). Pre-prosthetic cast surgery was performed for teeth Nos. 5 through 8 by removing and preparing a socket to set each denture tooth. The labial ridge was reduced by 1.5 mm to allow for lost tissue and bone during surgery and to provide a more esthetic emergence profile (Figure 7).

Before removing teeth from a cast for an immediate prosthesis, the technician should always check with the restorative dentist or surgeon regarding surgical procedures such as bone grafting or socket augmentation. These surgical procedures will affect the contour of ridge and thus proper cast trimming is critical. In this case, the surgeon was going to perform conventional extraction procedures without grafting or augmentation so the cast was being contoured appropriately. The author contoured the denture teeth on the patient’s right side and set each of them in the appropriate socket according to instructions (Figure 8). He set the posterior teeth on the patient’s right side. According to occlusal contacts and maxillary cast analysis, a modified cross-bite was evident in the first and second molar areas (Figure 9). A compromise in the occlusal contacts was needed due to the over-contoured buccal surface of crown No. 3. If right premolars and molars were set in a classic occlusal relationship with maxillary lingual cusp of No. 3 into central fossa of No. 30, then the maxillary buccal cusps would be over the vestibular area, thus increasing palatal flexure during functional occlusion. Posterior teeth Nos. 4 and 5 were set as transitional teeth in a compromised modified cross-bite occlusal scheme. The remaining denture teeth were placed and gingival wax was contoured to provide an esthetic smile (Figure 10).

To verify the proper placement of the anterior teeth according to instructions, an incisal index was created before pre-prosthetic cast surgery. The index with teeth was on the patient’s right side, and negative space where teeth needed to be set was on the left (Figure 11). The completed waxed tooth arrangement was remounted on an articulator, and the incisal edge placement was verified using the index that was previously made (Figure 12). The incisal edges were lingual to the black markings by 1.5 mm and raised by 1.5 mm as well.

The occlusal and palatal view of the completed tooth arrangement showed wax contouring with a duplicate palate stent (0.020 vacuum form) waxed in place (Figure 13). The occlusal view of the mandibular posterior contacts showed that the occlusal contacts were verified before investing as marked in red (Figure 14 ). The author then invested the first half of the immediate complete denture prosthetic and sprued it for continuous press injection mold processing (Figure 15 ).

The second half of the denture was created in VPS/silicone with mounting stone, the wax was eliminated, and then the teeth were meticulously cleaned (Figure 16 ). To prepare the denture for injection processing, the author cleaned the positive mold with the master cast, smoothed the tooth sockets, and removed the interproximal ridges (Figure 17). The ridge where the teeth were extracted during pre-prosthetic cast surgery was smoothed with a knife and sandpaper before a separator was applied for injection processing (Figure 18). After the complete immediate denture was processed, de-vested, and remounted to verify occlusal contacts, the master cast was carefully removed and intaglio exposed. The labial undercut on peripheral border was overextended and needed to be reduced by trimming the acrylic resin back. This elimination of labial undercut in intaglio surface allowed the immediate complete denture prosthesis to be easily inserted after extraction of teeth (Figure 19 ).

The black line on the overextended border showed where the reduction needed to take place (Figure 20 ). It is always better to under-extend the peripheral borders rather than overextend them. An overextended border will prevent the surgeon from seating the immediate denture and require chairside adjustments of acrylic resin. After post extraction and healing complete, the denture will be relined or tissue conditioned and the immediate denture will be extended back into labial undercut for increased retention and stability.

The author trimmed the overextended labial undercut and then polished the peripheral borders (Figure 21), which allowed the denture to be seated after surgical extractions. After the immediate complete denture was polished, the author made a VPS/addition reaction silicone index of the intaglio surface, representing the pre-prosthetic surgical ridge reduction (Figure 22). The silicone cast was used to create a clear surgical stent for verification of ridge reduction before insertion of the immediate complete denture (Figure 23 ).

Complete immediate denture surgical techniques should be discussed with the restorative clinician or surgeon and finished with a clear surgical stent if prescribed by the clinician. The clear surgical stent, which is delivered in disinfectant to the restorative clinician or surgeon, enables a surgeon to visually check for pressure points before inserting the immediate denture. The final labial view of the complete immediate denture prosthesis (Figure 24) showed anterior incisal placement and posterior tooth position in relation to the mandibular teeth and edentulous ridge on the patient’s left side.

Conclusion

While biology dictates prosthetic design and biomechanical considerations, an immediate complete denture must attempt to maintain and preserve existing opposing natural dentition. Residual ridge to occlusal surface relationship combined with a patient’s expectations will determine denture tooth placement and the best restorative material to use. As an important part of the prosthetic restorative team, dental technicians can help to improve the quality of a patient’s life while understanding that an immediate complete denture is a very traumatic and life-changing experience for a patient about to be edentulated on their maxillary or mandibular arch.